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sqlite3.c

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.5.9.  By combining all the individual C code files into this 
** single large file, the entire code can be compiled as a one translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% are more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other
** programs, you need this file and the "sqlite3.h" header file that defines
** the programming interface to the SQLite library.  (If you do not have 
** the "sqlite3.h" header file at hand, you will find a copy in the first
** 5638 lines past this header comment.)  Additional code files may be
** needed if you want a wrapper to interface SQLite with your choice of
** programming language.  The code for the "sqlite3" command-line shell
** is also in a separate file.  This file contains only code for the core
** SQLite library.
**
** This amalgamation was generated on 2008-05-14 16:20:58 UTC.
*/
#define SQLITE_CORE 1
#define SQLITE_AMALGAMATION 1
#ifndef SQLITE_PRIVATE
# define SQLITE_PRIVATE static
#endif
#ifndef SQLITE_API
# define SQLITE_API
#endif
/************** Begin file sqliteInt.h ***************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.704 2008/05/13 13:27:34 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build
*/
#ifdef _HAVE_SQLITE_CONFIG_H
#include "config.h"
#endif

/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
/************** Begin file sqliteLimit.h *************************************/
/*
** 2007 May 7
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** 
** This file defines various limits of what SQLite can process.
**
** @(#) $Id: sqliteLimit.h,v 1.8 2008/03/26 15:56:22 drh Exp $
*/

/*
** The maximum length of a TEXT or BLOB in bytes.   This also
** limits the size of a row in a table or index.
**
** The hard limit is the ability of a 32-bit signed integer
** to count the size: 2^31-1 or 2147483647.
*/
#ifndef SQLITE_MAX_LENGTH
# define SQLITE_MAX_LENGTH 1000000000
#endif

/*
** This is the maximum number of
**
**    * Columns in a table
**    * Columns in an index
**    * Columns in a view
**    * Terms in the SET clause of an UPDATE statement
**    * Terms in the result set of a SELECT statement
**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
**    * Terms in the VALUES clause of an INSERT statement
**
** The hard upper limit here is 32676.  Most database people will
** tell you that in a well-normalized database, you usually should
** not have more than a dozen or so columns in any table.  And if
** that is the case, there is no point in having more than a few
** dozen values in any of the other situations described above.
*/
#ifndef SQLITE_MAX_COLUMN
# define SQLITE_MAX_COLUMN 2000
#endif

/*
** The maximum length of a single SQL statement in bytes.
**
** It used to be the case that setting this value to zero would
** turn the limit off.  That is no longer true.  It is not possible
** to turn this limit off.
*/
#ifndef SQLITE_MAX_SQL_LENGTH
# define SQLITE_MAX_SQL_LENGTH 1000000000
#endif

/*
** The maximum depth of an expression tree. This is limited to 
** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 
** want to place more severe limits on the complexity of an 
** expression.
**
** A value of 0 used to mean that the limit was not enforced.
** But that is no longer true.  The limit is now strictly enforced
** at all times.
*/
#ifndef SQLITE_MAX_EXPR_DEPTH
# define SQLITE_MAX_EXPR_DEPTH 1000
#endif

/*
** The maximum number of terms in a compound SELECT statement.
** The code generator for compound SELECT statements does one
** level of recursion for each term.  A stack overflow can result
** if the number of terms is too large.  In practice, most SQL
** never has more than 3 or 4 terms.  Use a value of 0 to disable
** any limit on the number of terms in a compount SELECT.
*/
#ifndef SQLITE_MAX_COMPOUND_SELECT
# define SQLITE_MAX_COMPOUND_SELECT 500
#endif

/*
** The maximum number of opcodes in a VDBE program.
** Not currently enforced.
*/
#ifndef SQLITE_MAX_VDBE_OP
# define SQLITE_MAX_VDBE_OP 25000
#endif

/*
** The maximum number of arguments to an SQL function.
*/
#ifndef SQLITE_MAX_FUNCTION_ARG
# define SQLITE_MAX_FUNCTION_ARG 100
#endif

/*
** The maximum number of in-memory pages to use for the main database
** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
*/
#ifndef SQLITE_DEFAULT_CACHE_SIZE
# define SQLITE_DEFAULT_CACHE_SIZE  2000
#endif
#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
#endif

/*
** The maximum number of attached databases.  This must be between 0
** and 30.  The upper bound on 30 is because a 32-bit integer bitmap
** is used internally to track attached databases.
*/
#ifndef SQLITE_MAX_ATTACHED
# define SQLITE_MAX_ATTACHED 10
#endif


/*
** The maximum value of a ?nnn wildcard that the parser will accept.
*/
#ifndef SQLITE_MAX_VARIABLE_NUMBER
# define SQLITE_MAX_VARIABLE_NUMBER 999
#endif

/* Maximum page size.  The upper bound on this value is 32768.  This a limit
** imposed by the necessity of storing the value in a 2-byte unsigned integer
** and the fact that the page size must be a power of 2.
*/
#ifndef SQLITE_MAX_PAGE_SIZE
# define SQLITE_MAX_PAGE_SIZE 32768
#endif


/*
** The default size of a database page.
*/
#ifndef SQLITE_DEFAULT_PAGE_SIZE
# define SQLITE_DEFAULT_PAGE_SIZE 1024
#endif
#if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
# undef SQLITE_DEFAULT_PAGE_SIZE
# define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
#endif

/*
** Ordinarily, if no value is explicitly provided, SQLite creates databases
** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
** device characteristics (sector-size and atomic write() support),
** SQLite may choose a larger value. This constant is the maximum value
** SQLite will choose on its own.
*/
#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
#endif
#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
#endif


/*
** Maximum number of pages in one database file.
**
** This is really just the default value for the max_page_count pragma.
** This value can be lowered (or raised) at run-time using that the
** max_page_count macro.
*/
#ifndef SQLITE_MAX_PAGE_COUNT
# define SQLITE_MAX_PAGE_COUNT 1073741823
#endif

/*
** Maximum length (in bytes) of the pattern in a LIKE or GLOB
** operator.
*/
#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
#endif

/************** End of sqliteLimit.h *****************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/* Disable nuisance warnings on Borland compilers */
#if defined(__BORLANDC__)
#pragma warn -rch /* unreachable code */
#pragma warn -ccc /* Condition is always true or false */
#pragma warn -aus /* Assigned value is never used */
#pragma warn -csu /* Comparing signed and unsigned */
#pragma warn -spa /* Suspicous pointer arithmetic */
#endif

/* Needed for various definitions... */
#define _GNU_SOURCE

/*
** Include standard header files as necessary
*/
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif

/*
** A macro used to aid in coverage testing.  When doing coverage
** testing, the condition inside the argument must be evaluated 
** both true and false in order to get full branch coverage.
** This macro can be inserted to ensure adequate test coverage
** in places where simple condition/decision coverage is inadequate.
*/
#ifdef SQLITE_COVERAGE_TEST
SQLITE_PRIVATE   void sqlite3Coverage(int);
# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
#else
# define testcase(X)
#endif


/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
** a boolean expression that is usually true.  GCC is able to
** use these hints to generate better code, sometimes.
*/
#if defined(__GNUC__) && 0
# define likely(X)    __builtin_expect((X),1)
# define unlikely(X)  __builtin_expect((X),0)
#else
# define likely(X)    !!(X)
# define unlikely(X)  !!(X)
#endif


/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks
** large file support, or if the OS is windows, these should be no-ops.
**
** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
** system #includes.  Hence, this block of code must be the very first
** code in all source files.
**
** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
** on the compiler command line.  This is necessary if you are compiling
** on a recent machine (ex: RedHat 7.2) but you want your code to work
** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
** without this option, LFS is enable.  But LFS does not exist in the kernel
** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
** portability you should omit LFS.
**
** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
*/
#ifndef SQLITE_DISABLE_LFS
# define _LARGE_FILE       1
# ifndef _FILE_OFFSET_BITS
#   define _FILE_OFFSET_BITS 64
# endif
# define _LARGEFILE_SOURCE 1
#endif


/*
** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
** Older versions of SQLite used an optional THREADSAFE macro.
** We support that for legacy
*/
#if !defined(SQLITE_THREADSAFE)
#if defined(THREADSAFE)
# define SQLITE_THREADSAFE THREADSAFE
#else
# define SQLITE_THREADSAFE 1
#endif
#endif

/*
** Exactly one of the following macros must be defined in order to
** specify which memory allocation subsystem to use.
**
**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
**     SQLITE_MEMORY_SIZE            // internal allocator #1
**     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
**     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
**
** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
** the default.
*/
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
    defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
    defined(SQLITE_POW2_MEMORY_SIZE)>1
# error "At most one of the following compile-time configuration options\
 is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
 SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
#endif
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
    defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
    defined(SQLITE_POW2_MEMORY_SIZE)==0
# define SQLITE_SYSTEM_MALLOC 1
#endif

/*
** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the
** sizes of memory allocations below this value where possible.
*/
#if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT)
# define SQLITE_MALLOC_SOFT_LIMIT 1024
#endif

/*
** We need to define _XOPEN_SOURCE as follows in order to enable
** recursive mutexes on most unix systems.  But Mac OS X is different.
** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
** so it is omitted there.  See ticket #2673.
**
** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
** implemented on some systems.  So we avoid defining it at all
** if it is already defined or if it is unneeded because we are
** not doing a threadsafe build.  Ticket #2681.
**
** See also ticket #2741.
*/
#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
#  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
#endif

#if defined(SQLITE_TCL) || defined(TCLSH)
# include <tcl.h>
#endif

/*
** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
** Setting NDEBUG makes the code smaller and run faster.  So the following
** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
** feature.
*/
#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
# define NDEBUG 1
#endif

/************** Include sqlite3.h in the middle of sqliteInt.h ***************/
/************** Begin file sqlite3.h *****************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.  If a C-function, structure, datatype,
** or constant definition does not appear in this file, then it is
** not a published API of SQLite, is subject to change without
** notice, and should not be referenced by programs that use SQLite.
**
** Some of the definitions that are in this file are marked as
** "experimental".  Experimental interfaces are normally new
** features recently added to SQLite.  We do not anticipate changes 
** to experimental interfaces but reserve to make minor changes if
** experience from use "in the wild" suggest such changes are prudent.
**
** The official C-language API documentation for SQLite is derived
** from comments in this file.  This file is the authoritative source
** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.312 2008/05/12 12:39:56 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
*/
#if 0
extern "C" {
#endif


/*
** Add the ability to override 'extern'
*/
#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif

/*
** Make sure these symbols where not defined by some previous header
** file.
*/
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif

/*
** CAPI3REF: Compile-Time Library Version Numbers {F10010}
**
** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in
** the sqlite3.h file specify the version of SQLite with which
** that header file is associated.
**
** The "version" of SQLite is a string of the form "X.Y.Z".
** The phrase "alpha" or "beta" might be appended after the Z.
** The X value is major version number always 3 in SQLite3.
** The X value only changes when  backwards compatibility is
** broken and we intend to never break
** backwards compatibility.  The Y value is the minor version
** number and only changes when
** there are major feature enhancements that are forwards compatible
** but not backwards compatible.  The Z value is release number
** and is incremented with
** each release but resets back to 0 when Y is incremented.
**
** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
**
** INVARIANTS:
**
** {F10011} The SQLITE_VERSION #define in the sqlite3.h header file
**          evaluates to a string literal that is the SQLite version
**          with which the header file is associated.
**
** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer
**          with the value  (X*1000000 + Y*1000 + Z) where X, Y, and
**          Z are the major version, minor version, and release number.
*/
#define SQLITE_VERSION         "3.5.9"
#define SQLITE_VERSION_NUMBER  3005009

/*
** CAPI3REF: Run-Time Library Version Numbers {F10020}
** KEYWORDS: sqlite3_version
**
** These features provide the same information as the [SQLITE_VERSION]
** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated
** with the library instead of the header file.  Cautious programmers might
** include a check in their application to verify that 
** sqlite3_libversion_number() always returns the value 
** [SQLITE_VERSION_NUMBER].
**
** The sqlite3_libversion() function returns the same information as is
** in the sqlite3_version[] string constant.  The function is provided
** for use in DLLs since DLL users usually do not have direct access to string
** constants within the DLL.
**
** INVARIANTS:
**
** {F10021} The [sqlite3_libversion_number()] interface returns an integer
**          equal to [SQLITE_VERSION_NUMBER]. 
**
** {F10022} The [sqlite3_version] string constant contains the text of the
**          [SQLITE_VERSION] string. 
**
** {F10023} The [sqlite3_libversion()] function returns
**          a pointer to the [sqlite3_version] string constant.
*/
SQLITE_API const char sqlite3_version[];
SQLITE_API const char *sqlite3_libversion(void);
SQLITE_API int sqlite3_libversion_number(void);

/*
** CAPI3REF: Test To See If The Library Is Threadsafe {F10100}
**
** SQLite can be compiled with or without mutexes.  When
** the SQLITE_THREADSAFE C preprocessor macro is true, mutexes
** are enabled and SQLite is threadsafe.  When that macro is false,
** the mutexes are omitted.  Without the mutexes, it is not safe
** to use SQLite from more than one thread.
**
** There is a measurable performance penalty for enabling mutexes.
** So if speed is of utmost importance, it makes sense to disable
** the mutexes.  But for maximum safety, mutexes should be enabled.
** The default behavior is for mutexes to be enabled.
**
** This interface can be used by a program to make sure that the
** version of SQLite that it is linking against was compiled with
** the desired setting of the SQLITE_THREADSAFE macro.
**
** INVARIANTS:
**
** {F10101} The [sqlite3_threadsafe()] function returns nonzero if
**          SQLite was compiled with its mutexes enabled or zero
**          if SQLite was compiled with mutexes disabled.
*/
SQLITE_API int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle {F12000}
** KEYWORDS: {database connection} {database connections}
**
** Each open SQLite database is represented by pointer to an instance of the
** opaque structure named "sqlite3".  It is useful to think of an sqlite3
** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
** [sqlite3_open_v2()] interfaces are its constructors
** and [sqlite3_close()] is its destructor.  There are many other interfaces
** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and
** [sqlite3_busy_timeout()] to name but three) that are methods on this
** object.
*/
typedef struct sqlite3 sqlite3;


/*
** CAPI3REF: 64-Bit Integer Types {F10200}
** KEYWORDS: sqlite_int64 sqlite_uint64
**
** Because there is no cross-platform way to specify 64-bit integer types
** SQLite includes typedefs for 64-bit signed and unsigned integers.
**
** The sqlite3_int64 and sqlite3_uint64 are the preferred type
** definitions.  The sqlite_int64 and sqlite_uint64 types are
** supported for backwards compatibility only.
**
** INVARIANTS:
**
** {F10201} The [sqlite_int64] and [sqlite3_int64] types specify a
**          64-bit signed integer.
**
** {F10202} The [sqlite_uint64] and [sqlite3_uint64] types specify
**          a 64-bit unsigned integer.
*/
#ifdef SQLITE_INT64_TYPE
  typedef SQLITE_INT64_TYPE sqlite_int64;
  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
  typedef __int64 sqlite_int64;
  typedef unsigned __int64 sqlite_uint64;
#else
  typedef long long int sqlite_int64;
  typedef unsigned long long int sqlite_uint64;
#endif
typedef sqlite_int64 sqlite3_int64;
typedef sqlite_uint64 sqlite3_uint64;

/*
** If compiling for a processor that lacks floating point support,
** substitute integer for floating-point
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif

/*
** CAPI3REF: Closing A Database Connection {F12010}
**
** This routine is the destructor for the [sqlite3] object.  
**
** Applications should [sqlite3_finalize | finalize] all
** [prepared statements] and
** [sqlite3_blob_close | close] all [sqlite3_blob | BLOBs] 
** associated with the [sqlite3] object prior
** to attempting to close the [sqlite3] object.
**
** <todo>What happens to pending transactions?  Are they
** rolled back, or abandoned?</todo>
**
** INVARIANTS:
**
** {F12011} The [sqlite3_close()] interface destroys an [sqlite3] object
**          allocated by a prior call to [sqlite3_open()],
**          [sqlite3_open16()], or [sqlite3_open_v2()].
**
** {F12012} The [sqlite3_close()] function releases all memory used by the
**          connection and closes all open files.
**
** {F12013} If the database connection contains
**          [prepared statements] that have not been
**          finalized by [sqlite3_finalize()], then [sqlite3_close()]
**          returns [SQLITE_BUSY] and leaves the connection open.
**
** {F12014} Giving sqlite3_close() a NULL pointer is a harmless no-op.
**
** LIMITATIONS:
**
** {U12015} The parameter to [sqlite3_close()] must be an [sqlite3] object
**          pointer previously obtained from [sqlite3_open()] or the 
**          equivalent, or NULL.
**
** {U12016} The parameter to [sqlite3_close()] must not have been previously
**          closed.
*/
SQLITE_API int sqlite3_close(sqlite3 *);

/*
** The type for a callback function.
** This is legacy and deprecated.  It is included for historical
** compatibility and is not documented.
*/
typedef int (*sqlite3_callback)(void*,int,char**, char**);

/*
** CAPI3REF: One-Step Query Execution Interface {F12100}
**
** The sqlite3_exec() interface is a convenient way of running
** one or more SQL statements without a lot of C code.  The
** SQL statements are passed in as the second parameter to
** sqlite3_exec().  The statements are evaluated one by one
** until either an error or an interrupt is encountered or
** until they are all done.  The 3rd parameter is an optional
** callback that is invoked once for each row of any query results
** produced by the SQL statements.  The 5th parameter tells where
** to write any error messages.
**
** The sqlite3_exec() interface is implemented in terms of
** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].
** The sqlite3_exec() routine does nothing that cannot be done
** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].
** The sqlite3_exec() is just a convenient wrapper.
**
** INVARIANTS:
** 
** {F12101} The [sqlite3_exec()] interface evaluates zero or more UTF-8
**          encoded, semicolon-separated, SQL statements in the
**          zero-terminated string of its 2nd parameter within the
**          context of the [sqlite3] object given in the 1st parameter.
**
** {F12104} The return value of [sqlite3_exec()] is SQLITE_OK if all
**          SQL statements run successfully.
**
** {F12105} The return value of [sqlite3_exec()] is an appropriate 
**          non-zero error code if any SQL statement fails.
**
** {F12107} If one or more of the SQL statements handed to [sqlite3_exec()]
**          return results and the 3rd parameter is not NULL, then
**          the callback function specified by the 3rd parameter is
**          invoked once for each row of result.
**
** {F12110} If the callback returns a non-zero value then [sqlite3_exec()]
**          will aborted the SQL statement it is currently evaluating,
**          skip all subsequent SQL statements, and return [SQLITE_ABORT].
**          <todo>What happens to *errmsg here?  Does the result code for
**          sqlite3_errcode() get set?</todo>
**
** {F12113} The [sqlite3_exec()] routine will pass its 4th parameter through
**          as the 1st parameter of the callback.
**
** {F12116} The [sqlite3_exec()] routine sets the 2nd parameter of its
**          callback to be the number of columns in the current row of
**          result.
**
** {F12119} The [sqlite3_exec()] routine sets the 3rd parameter of its 
**          callback to be an array of pointers to strings holding the
**          values for each column in the current result set row as
**          obtained from [sqlite3_column_text()].
**
** {F12122} The [sqlite3_exec()] routine sets the 4th parameter of its
**          callback to be an array of pointers to strings holding the
**          names of result columns as obtained from [sqlite3_column_name()].
**
** {F12125} If the 3rd parameter to [sqlite3_exec()] is NULL then
**          [sqlite3_exec()] never invokes a callback.  All query
**          results are silently discarded.
**
** {F12128} If an error occurs while parsing or evaluating any of the SQL
**          statements handed to [sqlite3_exec()] then [sqlite3_exec()] will
**          return an [error code] other than [SQLITE_OK].
**
** {F12131} If an error occurs while parsing or evaluating any of the SQL
**          handed to [sqlite3_exec()] and if the 5th parameter (errmsg)
**          to [sqlite3_exec()] is not NULL, then an error message is
**          allocated using the equivalent of [sqlite3_mprintf()] and
**          *errmsg is made to point to that message.
**
** {F12134} The [sqlite3_exec()] routine does not change the value of
**          *errmsg if errmsg is NULL or if there are no errors.
**
** {F12137} The [sqlite3_exec()] function sets the error code and message
**          accessible via [sqlite3_errcode()], [sqlite3_errmsg()], and
**          [sqlite3_errmsg16()].
**
** LIMITATIONS:
**
** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open
**          [database connection].
**
** {U12142} The database connection must not be closed while
**          [sqlite3_exec()] is running.
** 
** {U12143} The calling function is should use [sqlite3_free()] to free
**          the memory that *errmsg is left pointing at once the error
**          message is no longer needed.
**
** {U12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()]
**          must remain unchanged while [sqlite3_exec()] is running.
*/
SQLITE_API int sqlite3_exec(
  sqlite3*,                                  /* An open database */
  const char *sql,                           /* SQL to be evaluted */
  int (*callback)(void*,int,char**,char**),  /* Callback function */
  void *,                                    /* 1st argument to callback */
  char **errmsg                              /* Error msg written here */
);

/*
** CAPI3REF: Result Codes {F10210}
** KEYWORDS: SQLITE_OK {error code} {error codes}
**
** Many SQLite functions return an integer result code from the set shown
** here in order to indicates success or failure.
**
** See also: [SQLITE_IOERR_READ | extended result codes]
*/
#define SQLITE_OK           0   /* Successful result */
/* beginning-of-error-codes */
#define SQLITE_ERROR        1   /* SQL error or missing database */
#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
#define SQLITE_PERM         3   /* Access permission denied */
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
#define SQLITE_BUSY         5   /* The database file is locked */
#define SQLITE_LOCKED       6   /* A table in the database is locked */
#define SQLITE_NOMEM        7   /* A malloc() failed */
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
#define SQLITE_FULL        13   /* Insertion failed because database is full */
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */
#define SQLITE_EMPTY       16   /* Database is empty */
#define SQLITE_SCHEMA      17   /* The database schema changed */
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
#define SQLITE_MISMATCH    20   /* Data type mismatch */
#define SQLITE_MISUSE      21   /* Library used incorrectly */
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
#define SQLITE_AUTH        23   /* Authorization denied */
#define SQLITE_FORMAT      24   /* Auxiliary database format error */
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
/* end-of-error-codes */

/*
** CAPI3REF: Extended Result Codes {F10220}
** KEYWORDS: {extended error code} {extended error codes}
** KEYWORDS: {extended result codes}
**
** In its default configuration, SQLite API routines return one of 26 integer
** [SQLITE_OK | result codes].  However, experience has shown that
** many of these result codes are too course-grained.  They do not provide as
** much information about problems as programmers might like.  In an effort to
** address this, newer versions of SQLite (version 3.3.8 and later) include
** support for additional result codes that provide more detailed information
** about errors. The extended result codes are enabled or disabled
** for each database connection using the [sqlite3_extended_result_codes()]
** API.
** 
** Some of the available extended result codes are listed here.
** One may expect the number of extended result codes will be expand
** over time.  Software that uses extended result codes should expect
** to see new result codes in future releases of SQLite.
**
** The SQLITE_OK result code will never be extended.  It will always
** be exactly zero.
** 
** INVARIANTS:
**
** {F10223} The symbolic name for an extended result code always contains
**          a related primary result code as a prefix.
**
** {F10224} Primary result code names contain a single "_" character.
**
** {F10225} Extended result code names contain two or more "_" characters.
**
** {F10226} The numeric value of an extended result code contains the
**          numeric value of its corresponding primary result code in
**          its least significant 8 bits.
*/
#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
#define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
#define SQLITE_IOERR_BLOCKED       (SQLITE_IOERR | (11<<8))
#define SQLITE_IOERR_NOMEM         (SQLITE_IOERR | (12<<8))

/*
** CAPI3REF: Flags For File Open Operations {F10230}
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the xOpen method of the
** [sqlite3_vfs] object.
*/
#define SQLITE_OPEN_READONLY         0x00000001
#define SQLITE_OPEN_READWRITE        0x00000002
#define SQLITE_OPEN_CREATE           0x00000004
#define SQLITE_OPEN_DELETEONCLOSE    0x00000008
#define SQLITE_OPEN_EXCLUSIVE        0x00000010
#define SQLITE_OPEN_MAIN_DB          0x00000100
#define SQLITE_OPEN_TEMP_DB          0x00000200
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000
#define SQLITE_OPEN_SUBJOURNAL       0x00002000
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000

/*
** CAPI3REF: Device Characteristics {F10240}
**
** The xDeviceCapabilities method of the [sqlite3_io_methods]
** object returns an integer which is a vector of the these
** bit values expressing I/O characteristics of the mass storage
** device that holds the file that the [sqlite3_io_methods]
** refers to.
**
** The SQLITE_IOCAP_ATOMIC property means that all writes of
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
** mean that writes of blocks that are nnn bytes in size and
** are aligned to an address which is an integer multiple of
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
** that when data is appended to a file, the data is appended
** first then the size of the file is extended, never the other
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
** information is written to disk in the same order as calls
** to xWrite().
*/
#define SQLITE_IOCAP_ATOMIC          0x00000001
#define SQLITE_IOCAP_ATOMIC512       0x00000002
#define SQLITE_IOCAP_ATOMIC1K        0x00000004
#define SQLITE_IOCAP_ATOMIC2K        0x00000008
#define SQLITE_IOCAP_ATOMIC4K        0x00000010
#define SQLITE_IOCAP_ATOMIC8K        0x00000020
#define SQLITE_IOCAP_ATOMIC16K       0x00000040
#define SQLITE_IOCAP_ATOMIC32K       0x00000080
#define SQLITE_IOCAP_ATOMIC64K       0x00000100
#define SQLITE_IOCAP_SAFE_APPEND     0x00000200
#define SQLITE_IOCAP_SEQUENTIAL      0x00000400

/*
** CAPI3REF: File Locking Levels {F10250}
**
** SQLite uses one of these integer values as the second
** argument to calls it makes to the xLock() and xUnlock() methods
** of an [sqlite3_io_methods] object.
*/
#define SQLITE_LOCK_NONE          0
#define SQLITE_LOCK_SHARED        1
#define SQLITE_LOCK_RESERVED      2
#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4

/*
** CAPI3REF: Synchronization Type Flags {F10260}
**
** When SQLite invokes the xSync() method of an
** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 
** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 
** to use Mac OS-X style fullsync instead of fsync().
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010


/*
** CAPI3REF: OS Interface Open File Handle {F11110}
**
** An [sqlite3_file] object represents an open file in the OS
** interface layer.  Individual OS interface implementations will
** want to subclass this object by appending additional fields
** for their own use.  The pMethods entry is a pointer to an
** [sqlite3_io_methods] object that defines methods for performing
** I/O operations on the open file.
*/
typedef struct sqlite3_file sqlite3_file;
struct sqlite3_file {
  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
};

/*
** CAPI3REF: OS Interface File Virtual Methods Object {F11120}
**
** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to
** an instance of this object.  This object defines the
** methods used to perform various operations against the open file.
**
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
*  The second choice is an
** OS-X style fullsync.  The SQLITE_SYNC_DATA flag may be ORed in to
** indicate that only the data of the file and not its inode needs to be
** synced.
** 
** The integer values to xLock() and xUnlock() are one of
** <ul>
** <li> [SQLITE_LOCK_NONE],
** <li> [SQLITE_LOCK_SHARED],
** <li> [SQLITE_LOCK_RESERVED],
** <li> [SQLITE_LOCK_PENDING], or
** <li> [SQLITE_LOCK_EXCLUSIVE].
** </ul>
** xLock() increases the lock. xUnlock() decreases the lock.  
** The xCheckReservedLock() method looks
** to see if any database connection, either in this
** process or in some other process, is holding an RESERVED,
** PENDING, or EXCLUSIVE lock on the file.  It returns true
** if such a lock exists and false if not.
** 
** The xFileControl() method is a generic interface that allows custom
** VFS implementations to directly control an open file using the
** [sqlite3_file_control()] interface.  The second "op" argument
** is an integer opcode.   The third
** argument is a generic pointer which is intended to be a pointer
** to a structure that may contain arguments or space in which to
** write return values.  Potential uses for xFileControl() might be
** functions to enable blocking locks with timeouts, to change the
** locking strategy (for example to use dot-file locks), to inquire
** about the status of a lock, or to break stale locks.  The SQLite
** core reserves opcodes less than 100 for its own use. 
** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
** Applications that define a custom xFileControl method should use opcodes 
** greater than 100 to avoid conflicts.
**
** The xSectorSize() method returns the sector size of the
** device that underlies the file.  The sector size is the
** minimum write that can be performed without disturbing
** other bytes in the file.  The xDeviceCharacteristics()
** method returns a bit vector describing behaviors of the
** underlying device:
**
** <ul>
** <li> [SQLITE_IOCAP_ATOMIC]
** <li> [SQLITE_IOCAP_ATOMIC512]
** <li> [SQLITE_IOCAP_ATOMIC1K]
** <li> [SQLITE_IOCAP_ATOMIC2K]
** <li> [SQLITE_IOCAP_ATOMIC4K]
** <li> [SQLITE_IOCAP_ATOMIC8K]
** <li> [SQLITE_IOCAP_ATOMIC16K]
** <li> [SQLITE_IOCAP_ATOMIC32K]
** <li> [SQLITE_IOCAP_ATOMIC64K]
** <li> [SQLITE_IOCAP_SAFE_APPEND]
** <li> [SQLITE_IOCAP_SEQUENTIAL]
** </ul>
**
** The SQLITE_IOCAP_ATOMIC property means that all writes of
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
** mean that writes of blocks that are nnn bytes in size and
** are aligned to an address which is an integer multiple of
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
** that when data is appended to a file, the data is appended
** first then the size of the file is extended, never the other
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
** information is written to disk in the same order as calls
** to xWrite().
*/
typedef struct sqlite3_io_methods sqlite3_io_methods;
struct sqlite3_io_methods {
  int iVersion;
  int (*xClose)(sqlite3_file*);
  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
  int (*xSync)(sqlite3_file*, int flags);
  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
  int (*xLock)(sqlite3_file*, int);
  int (*xUnlock)(sqlite3_file*, int);
  int (*xCheckReservedLock)(sqlite3_file*);
  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
  int (*xSectorSize)(sqlite3_file*);
  int (*xDeviceCharacteristics)(sqlite3_file*);
  /* Additional methods may be added in future releases */
};

/*
** CAPI3REF: Standard File Control Opcodes {F11310}
**
** These integer constants are opcodes for the xFileControl method
** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()]
** interface.
**
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
** into an integer that the pArg argument points to. This capability
** is used during testing and only needs to be supported when SQLITE_TEST
** is defined.
*/
#define SQLITE_FCNTL_LOCKSTATE        1

/*
** CAPI3REF: Mutex Handle {F17110}
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
** deals with pointers to the [sqlite3_mutex] object.
**
** Mutexes are created using [sqlite3_mutex_alloc()].
*/
typedef struct sqlite3_mutex sqlite3_mutex;

/*
** CAPI3REF: OS Interface Object {F11140}
**
** An instance of this object defines the interface between the
** SQLite core and the underlying operating system.  The "vfs"
** in the name of the object stands for "virtual file system".
**
** The iVersion field is initially 1 but may be larger for future
** versions of SQLite.  Additional fields may be appended to this
** object when the iVersion value is increased.
**
** The szOsFile field is the size of the subclassed [sqlite3_file]
** structure used by this VFS.  mxPathname is the maximum length of
** a pathname in this VFS.
**
** Registered sqlite3_vfs objects are kept on a linked list formed by
** the pNext pointer.  The [sqlite3_vfs_register()]
** and [sqlite3_vfs_unregister()] interfaces manage this list
** in a thread-safe way.  The [sqlite3_vfs_find()] interface
** searches the list.
**
** The pNext field is the only field in the sqlite3_vfs 
** structure that SQLite will ever modify.  SQLite will only access
** or modify this field while holding a particular static mutex.
** The application should never modify anything within the sqlite3_vfs
** object once the object has been registered.
**
** The zName field holds the name of the VFS module.  The name must
** be unique across all VFS modules.
**
** {F11141} SQLite will guarantee that the zFilename string passed to
** xOpen() is a full pathname as generated by xFullPathname() and
** that the string will be valid and unchanged until xClose() is
** called.  {END} So the [sqlite3_file] can store a pointer to the
** filename if it needs to remember the filename for some reason.
**
** {F11142} The flags argument to xOpen() includes all bits set in
** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
** or [sqlite3_open16()] is used, then flags includes at least
** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END}
** If xOpen() opens a file read-only then it sets *pOutFlags to
** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be
** set.
** 
** {F11143} SQLite will also add one of the following flags to the xOpen()
** call, depending on the object being opened:
** 
** <ul>
** <li>  [SQLITE_OPEN_MAIN_DB]
** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
** <li>  [SQLITE_OPEN_TEMP_DB]
** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
** <li>  [SQLITE_OPEN_TRANSIENT_DB]
** <li>  [SQLITE_OPEN_SUBJOURNAL]
** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
** </ul> {END}
**
** The file I/O implementation can use the object type flags to
** changes the way it deals with files.  For example, an application
** that does not care about crash recovery or rollback might make
** the open of a journal file a no-op.  Writes to this journal would
** also be no-ops, and any attempt to read the journal would return 
** SQLITE_IOERR.  Or the implementation might recognize that a database 
** file will be doing page-aligned sector reads and writes in a random 
** order and set up its I/O subsystem accordingly.
** 
** SQLite might also add one of the following flags to the xOpen
** method:
** 
** <ul>
** <li> [SQLITE_OPEN_DELETEONCLOSE]
** <li> [SQLITE_OPEN_EXCLUSIVE]
** </ul>
** 
** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
** deleted when it is closed.  {F11146} The [SQLITE_OPEN_DELETEONCLOSE]
** will be set for TEMP  databases, journals and for subjournals. 
** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
** for exclusive access.  This flag is set for all files except
** for the main database file. {END}
** 
** {F11148} At least szOsFile bytes of memory are allocated by SQLite 
** to hold the  [sqlite3_file] structure passed as the third 
** argument to xOpen.  {END}  The xOpen method does not have to
** allocate the structure; it should just fill it in.
** 
** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 
** to test for the existance of a file,
** or [SQLITE_ACCESS_READWRITE] to test to see
** if a file is readable and writable, or [SQLITE_ACCESS_READ]
** to test to see if a file is at least readable.  {END} The file can be a 
** directory.
** 
** {F11150} SQLite will always allocate at least mxPathname+1 bytes for
** the output buffers for xGetTempname and xFullPathname. {F11151} The exact
** size of the output buffer is also passed as a parameter to both 
** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN
** should be returned. As this is handled as a fatal error by SQLite,
** vfs implementations should endeavor to prevent this by setting 
** mxPathname to a sufficiently large value.
** 
** The xRandomness(), xSleep(), and xCurrentTime() interfaces
** are not strictly a part of the filesystem, but they are
** included in the VFS structure for completeness.
** The xRandomness() function attempts to return nBytes bytes
** of good-quality randomness into zOut.  The return value is
** the actual number of bytes of randomness obtained.  The
** xSleep() method causes the calling thread to sleep for at
** least the number of microseconds given.  The xCurrentTime()
** method returns a Julian Day Number for the current date and
** time.
*/
typedef struct sqlite3_vfs sqlite3_vfs;
struct sqlite3_vfs {
  int iVersion;            /* Structure version number */
  int szOsFile;            /* Size of subclassed sqlite3_file */
  int mxPathname;          /* Maximum file pathname length */
  sqlite3_vfs *pNext;      /* Next registered VFS */
  const char *zName;       /* Name of this virtual file system */
  void *pAppData;          /* Pointer to application-specific data */
  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
               int flags, int *pOutFlags);
  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags);
  int (*xGetTempname)(sqlite3_vfs*, int nOut, char *zOut);
  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
  void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol);
  void (*xDlClose)(sqlite3_vfs*, void*);
  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
  int (*xSleep)(sqlite3_vfs*, int microseconds);
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  /* New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. */
};

/*
** CAPI3REF: Flags for the xAccess VFS method {F11190}
**
** {F11191} These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object. {END}  They determine
** what kind of permissions the xAccess method is
** looking for.  {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method
** simply checks to see if the file exists. {F11193} With
** SQLITE_ACCESS_READWRITE, the xAccess method checks to see
** if the file is both readable and writable.  {F11194} With
** SQLITE_ACCESS_READ the xAccess method
** checks to see if the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2

/*
** CAPI3REF: Enable Or Disable Extended Result Codes {F12200}
**
** The sqlite3_extended_result_codes() routine enables or disables the
** [SQLITE_IOERR_READ | extended result codes] feature of SQLite.
** The extended result codes are disabled by default for historical
** compatibility.
**
** INVARIANTS:
**
** {F12201} Each new [database connection] has the 
**          [extended result codes] feature
**          disabled by default.
**
** {F12202} The [sqlite3_extended_result_codes(D,F)] interface will enable
**          [extended result codes] for the 
**          [database connection] D if the F parameter
**          is true, or disable them if F is false.
*/
SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid {F12220}
**
** Each entry in an SQLite table has a unique 64-bit signed
** integer key called the "rowid". The rowid is always available
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
** names are not also used by explicitly declared columns. If
** the table has a column of type INTEGER PRIMARY KEY then that column
** is another alias for the rowid.
**
** This routine returns the rowid of the most recent
** successful INSERT into the database from the database connection
** shown in the first argument.  If no successful inserts
** have ever occurred on this database connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the
** inserted row is returned by this routine as long as the trigger
** is running.  But once the trigger terminates, the value returned
** by this routine reverts to the last value inserted before the
** trigger fired.
**
** An INSERT that fails due to a constraint violation is not a
** successful insert and does not change the value returned by this
** routine.  Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
** and INSERT OR ABORT make no changes to the return value of this
** routine when their insertion fails.  When INSERT OR REPLACE 
** encounters a constraint violation, it does not fail.  The
** INSERT continues to completion after deleting rows that caused
** the constraint problem so INSERT OR REPLACE will always change
** the return value of this interface. 
**
** For the purposes of this routine, an insert is considered to
** be successful even if it is subsequently rolled back.
**
** INVARIANTS:
**
** {F12221} The [sqlite3_last_insert_rowid()] function returns the
**          rowid of the most recent successful insert done
**          on the same database connection and within the same
**          trigger context, or zero if there have
**          been no qualifying inserts on that connection.
**
** {F12223} The [sqlite3_last_insert_rowid()] function returns
**          same value when called from the same trigger context
**          immediately before and after a ROLLBACK.
**
** LIMITATIONS:
**
** {U12232} If a separate thread does a new insert on the same
**          database connection while the [sqlite3_last_insert_rowid()]
**          function is running and thus changes the last insert rowid,
**          then the value returned by [sqlite3_last_insert_rowid()] is
**          unpredictable and might not equal either the old or the new
**          last insert rowid.
*/
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {F12240}
**
** This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the connection specified by the first parameter.  Only
** changes that are directly specified by the INSERT, UPDATE, or
** DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted. Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of REPLACE constraint resolution,
** rollback, ABORT processing, DROP TABLE, or by any other
** mechanisms do not count as direct row changes.
**
** A "trigger context" is a scope of execution that begins and
** ends with the script of a trigger.  Most SQL statements are
** evaluated outside of any trigger.  This is the "top level"
** trigger context.  If a trigger fires from the top level, a
** new trigger context is entered for the duration of that one
** trigger.  Subtriggers create subcontexts for their duration.
**
** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** So when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.
** Within the body of a trigger, the sqlite3_changes() interface
** can be called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the same trigger.
** However, the number returned does not include in changes
** caused by subtriggers since they have their own context.
**
** SQLite implements the command "DELETE FROM table" without
** a WHERE clause by dropping and recreating the table.  (This is much
** faster than going through and deleting individual elements from the
** table.)  Because of this optimization, the deletions in
** "DELETE FROM table" are not row changes and will not be counted
** by the sqlite3_changes() or [sqlite3_total_changes()] functions.
** To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
**
** INVARIANTS:
**
** {F12241} The [sqlite3_changes()] function returns the number of
**          row changes caused by the most recent INSERT, UPDATE,
**          or DELETE statement on the same database connection and
**          within the same trigger context, or zero if there have
**          not been any qualifying row changes.
**
** LIMITATIONS:
**
** {U12252} If a separate thread makes changes on the same database connection
**          while [sqlite3_changes()] is running then the value returned
**          is unpredictable and unmeaningful.
*/
SQLITE_API int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified {F12260}
***
** This function returns the number of row changes caused
** by INSERT, UPDATE or DELETE statements since the database handle
** was opened.  The count includes all changes from all trigger
** contexts.  But the count does not include changes used to
** implement REPLACE constraints, do rollbacks or ABORT processing,
** or DROP table processing.
** The changes
** are counted as soon as the statement that makes them is completed 
** (when the statement handle is passed to [sqlite3_reset()] or 
** [sqlite3_finalize()]).
**
** SQLite implements the command "DELETE FROM table" without
** a WHERE clause by dropping and recreating the table.  (This is much
** faster than going
** through and deleting individual elements from the table.)  Because of
** this optimization, the change count for "DELETE FROM table" will be
** zero regardless of the number of elements that were originally in the
** table. To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
**
** See also the [sqlite3_changes()] interface.
**
** INVARIANTS:
** 
** {F12261} The [sqlite3_total_changes()] returns the total number
**          of row changes caused by INSERT, UPDATE, and/or DELETE
**          statements on the same [database connection], in any
**          trigger context, since the database connection was
**          created.
**
** LIMITATIONS:
**
** {U12264} If a separate thread makes changes on the same database connection
**          while [sqlite3_total_changes()] is running then the value 
**          returned is unpredictable and unmeaningful.
*/
SQLITE_API int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query {F12270}
**
** This function causes any pending database operation to abort and
** return at its earliest opportunity. This routine is typically
** called in response to a user action such as pressing "Cancel"
** or Ctrl-C where the user wants a long query operation to halt
** immediately.
**
** It is safe to call this routine from a thread different from the
** thread that is currently running the database operation.  But it
** is not safe to call this routine with a database connection that
** is closed or might close before sqlite3_interrupt() returns.
**
** If an SQL is very nearly finished at the time when sqlite3_interrupt()
** is called, then it might not have an opportunity to be interrupted.
** It might continue to completion.
** An SQL operation that is interrupted will return
** [SQLITE_INTERRUPT].  If the interrupted SQL operation is an
** INSERT, UPDATE, or DELETE that is inside an explicit transaction, 
** then the entire transaction will be rolled back automatically.
** A call to sqlite3_interrupt() has no effect on SQL statements
** that are started after sqlite3_interrupt() returns.
**
** INVARIANTS:
**
** {F12271} The [sqlite3_interrupt()] interface will force all running
**          SQL statements associated with the same database connection
**          to halt after processing at most one additional row of
**          data.
**
** {F12272} Any SQL statement that is interrupted by [sqlite3_interrupt()]
**          will return [SQLITE_INTERRUPT].
**
** LIMITATIONS:
**
** {U12279} If the database connection closes while [sqlite3_interrupt()]
**          is running then bad things will likely happen.
*/
SQLITE_API void sqlite3_interrupt(sqlite3*);

/*
** CAPI3REF: Determine If An SQL Statement Is Complete {F10510}
**
** These routines are useful for command-line input to determine if the
** currently entered text seems to form complete a SQL statement or
** if additional input is needed before sending the text into
** SQLite for parsing.  These routines return true if the input string
** appears to be a complete SQL statement.  A statement is judged to be
** complete if it ends with a semicolon token and is not a fragment of a
** CREATE TRIGGER statement.  Semicolons that are embedded within
** string literals or quoted identifier names or comments are not
** independent tokens (they are part of the token in which they are
** embedded) and thus do not count as a statement terminator.
**
** These routines do not parse the SQL and
** so will not detect syntactically incorrect SQL.
**
** INVARIANTS:
**
** {F10511} The sqlite3_complete() and sqlite3_complete16() functions
**          return true (non-zero) if and only if the last
**          non-whitespace token in their input is a semicolon that
**          is not in between the BEGIN and END of a CREATE TRIGGER
**          statement.
**
** LIMITATIONS:
**
** {U10512} The input to sqlite3_complete() must be a zero-terminated
**          UTF-8 string.
**
** {U10513} The input to sqlite3_complete16() must be a zero-terminated
**          UTF-16 string in native byte order.
*/
SQLITE_API int sqlite3_complete(const char *sql);
SQLITE_API int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310}
**
** This routine identifies a callback function that might be
** invoked whenever an attempt is made to open a database table 
** that another thread or process has locked.
** If the busy callback is NULL, then [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock.
** If the busy callback is not NULL, then the
** callback will be invoked with two arguments.  The
** first argument to the handler is a copy of the void* pointer which
** is the third argument to this routine.  The second argument to
** the handler is the number of times that the busy handler has
** been invoked for this locking event.   If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
** If the callback returns non-zero, then another attempt
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that
** it will be invoked when there is lock contention.
** If SQLite determines that invoking the busy handler could result in
** a deadlock, it will go ahead and return [SQLITE_BUSY] or
** [SQLITE_IOERR_BLOCKED] instead of invoking the
** busy handler.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock.  The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first.  If both processes
** invoke the busy handlers, neither will make any progress.  Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** The default busy callback is NULL.
**
** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache.  SQLite will
** already hold a RESERVED lock on the database file, but it needs
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
** forces an automatic rollback of the changes.  See the
** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**    
** There can only be a single busy handler defined for each database
** connection.  Setting a new busy handler clears any previous one. 
** Note that calling [sqlite3_busy_timeout()] will also set or clear
** the busy handler.
**
** INVARIANTS:
**
** {F12311} The [sqlite3_busy_handler()] function replaces the busy handler
**          callback in the database connection identified by the 1st
**          parameter with a new busy handler identified by the 2nd and 3rd
**          parameters.
**
** {F12312} The default busy handler for new database connections is NULL.
**
** {F12314} When two or more database connection share a common cache,
**          the busy handler for the database connection currently using
**          the cache is invoked when the cache encounters a lock.
**
** {F12316} If a busy handler callback returns zero, then the SQLite
**          interface that provoked the locking event will return
**          [SQLITE_BUSY].
**
** {F12318} SQLite will invokes the busy handler with two argument which
**          are a copy of the pointer supplied by the 3rd parameter to
**          [sqlite3_busy_handler()] and a count of the number of prior
**          invocations of the busy handler for the same locking event.
**
** LIMITATIONS:
**
** {U12319} A busy handler should not call close the database connection
**          or prepared statement that invoked the busy handler.
*/
SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {F12340}
**
** This routine sets a [sqlite3_busy_handler | busy handler]
** that sleeps for a while when a
** table is locked.  The handler will sleep multiple times until 
** at least "ms" milliseconds of sleeping have been done. {F12343} After
** "ms" milliseconds of sleeping, the handler returns 0 which
** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** There can only be a single busy handler for a particular database
** connection.  If another busy handler was defined  
** (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
**
** INVARIANTS:
**
** {F12341} The [sqlite3_busy_timeout()] function overrides any prior
**          [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting
**          on the same database connection.
**
** {F12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than
**          or equal to zero, then the busy handler is cleared so that
**          all subsequent locking events immediately return [SQLITE_BUSY].
**
** {F12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive
**          number N, then a busy handler is set that repeatedly calls
**          the xSleep() method in the VFS interface until either the
**          lock clears or until the cumulative sleep time reported back
**          by xSleep() exceeds N milliseconds.
*/
SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);

/*
** CAPI3REF: Convenience Routines For Running Queries {F12370}
**
** Definition: A <b>result table</b> is memory data structure created by the
** [sqlite3_get_table()] interface.  A result table records the
** complete query results from one or more queries.
**
** The table conceptually has a number of rows and columns.  But
** these numbers are not part of the result table itself.  These
** numbers are obtained separately.  Let N be the number of rows
** and M be the number of columns.
**
** A result table is an array of pointers to zero-terminated
** UTF-8 strings.  There are (N+1)*M elements in the array.  
** The first M pointers point to zero-terminated strings that 
** contain the names of the columns.
** The remaining entries all point to query results.  NULL
** values are give a NULL pointer.  All other values are in
** their UTF-8 zero-terminated string representation as returned by
** [sqlite3_column_text()].
**
** A result table might consists of one or more memory allocations.
** It is not safe to pass a result table directly to [sqlite3_free()].
** A result table should be deallocated using [sqlite3_free_table()].
**
** As an example of the result table format, suppose a query result
** is as follows:
**
** <blockquote><pre>
**        Name        | Age
**        -----------------------
**        Alice       | 43
**        Bob         | 28
**        Cindy       | 21
** </pre></blockquote>
**
** There are two column (M==2) and three rows (N==3).  Thus the
** result table has 8 entries.  Suppose the result table is stored
** in an array names azResult.  Then azResult holds this content:
**
** <blockquote><pre>
**        azResult&#91;0] = "Name";
**        azResult&#91;1] = "Age";
**        azResult&#91;2] = "Alice";
**        azResult&#91;3] = "43";
**        azResult&#91;4] = "Bob";
**        azResult&#91;5] = "28";
**        azResult&#91;6] = "Cindy";
**        azResult&#91;7] = "21";
** </pre></blockquote>
**
** The sqlite3_get_table() function evaluates one or more
** semicolon-separated SQL statements in the zero-terminated UTF-8
** string of its 2nd parameter.  It returns a result table to the
** pointer given in its 3rd parameter.
**
** After the calling function has finished using the result, it should 
** pass the pointer to the result table to sqlite3_free_table() in order to 
** release the memory that was malloc-ed.  Because of the way the 
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
** function must not try to call [sqlite3_free()] directly.  Only 
** [sqlite3_free_table()] is able to release the memory properly and safely.
**
** The sqlite3_get_table() interface is implemented as a wrapper around
** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
** to any internal data structures of SQLite.  It uses only the public
** interface defined here.  As a consequence, errors that occur in the
** wrapper layer outside of the internal [sqlite3_exec()] call are not
** reflected in subsequent calls to [sqlite3_errcode()] or
** [sqlite3_errmsg()].
**
** INVARIANTS:
**
** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then
**          it frees the result table under construction, aborts the
**          query in process, skips any subsequent queries, sets the
**          *resultp output pointer to NULL and returns [SQLITE_NOMEM].
**
** {F12373} If the ncolumn parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] write the number of columns in the
**          result set of the query into *ncolumn if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12374} If the nrow parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] write the number of rows in the
**          result set of the query into *nrow if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12376} The [sqlite3_get_table()] function sets its *ncolumn value
**          to the number of columns in the result set of the query in the
**          sql parameter, or to zero if the query in sql has an empty
**          result set.
*/
SQLITE_API int sqlite3_get_table(
  sqlite3*,             /* An open database */
  const char *sql,      /* SQL to be evaluated */
  char ***pResult,      /* Results of the query */
  int *nrow,            /* Number of result rows written here */
  int *ncolumn,         /* Number of result columns written here */
  char **errmsg         /* Error msg written here */
);
SQLITE_API void sqlite3_free_table(char **result);

/*
** CAPI3REF: Formatted String Printing Functions {F17400}
**
** These routines are workalikes of the "printf()" family of functions
** from the standard C library.
**
** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
** results into memory obtained from [sqlite3_malloc()].
** The strings returned by these two routines should be
** released by [sqlite3_free()].   Both routines return a
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
** memory to hold the resulting string.
**
** In sqlite3_snprintf() routine is similar to "snprintf()" from
** the standard C library.  The result is written into the
** buffer supplied as the second parameter whose size is given by
** the first parameter. Note that the order of the
** first two parameters is reversed from snprintf().  This is an
** historical accident that cannot be fixed without breaking
** backwards compatibility.  Note also that sqlite3_snprintf()
** returns a pointer to its buffer instead of the number of
** characters actually written into the buffer.  We admit that
** the number of characters written would be a more useful return
** value but we cannot change the implementation of sqlite3_snprintf()
** now without breaking compatibility.
**
** As long as the buffer size is greater than zero, sqlite3_snprintf()
** guarantees that the buffer is always zero-terminated.  The first
** parameter "n" is the total size of the buffer, including space for
** the zero terminator.  So the longest string that can be completely
** written will be n-1 characters.
**
** These routines all implement some additional formatting
** options that are useful for constructing SQL statements.
** All of the usual printf formatting options apply.  In addition, there
** is are "%q", "%Q", and "%z" options.
**
** The %q option works like %s in that it substitutes a null-terminated
** string from the argument list.  But %q also doubles every '\'' character.
** %q is designed for use inside a string literal.  By doubling each '\''
** character it escapes that character and allows it to be inserted into
** the string.
**
** For example, so some string variable contains text as follows:
**
** <blockquote><pre>
**  char *zText = "It's a happy day!";
** </pre></blockquote>
**
** One can use this text in an SQL statement as follows:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** Because the %q format string is used, the '\'' character in zText
** is escaped and the SQL generated is as follows:
**
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It''s a happy day!')
** </pre></blockquote>
**
** This is correct.  Had we used %s instead of %q, the generated SQL
** would have looked like this:
**
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It's a happy day!');
** </pre></blockquote>
**
** This second example is an SQL syntax error.  As a general rule you
** should always use %q instead of %s when inserting text into a string 
** literal.
**
** The %Q option works like %q except it also adds single quotes around
** the outside of the total string.  Or if the parameter in the argument
** list is a NULL pointer, %Q substitutes the text "NULL" (without single
** quotes) in place of the %Q option. {END}  So, for example, one could say:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** The code above will render a correct SQL statement in the zSQL
** variable even if the zText variable is a NULL pointer.
**
** The "%z" formatting option works exactly like "%s" with the
** addition that after the string has been read and copied into
** the result, [sqlite3_free()] is called on the input string. {END}
**
** INVARIANTS:
**
** {F17403}  The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces
**           return either pointers to zero-terminated UTF-8 strings held in
**           memory obtained from [sqlite3_malloc()] or NULL pointers if
**           a call to [sqlite3_malloc()] fails.
**
** {F17406}  The [sqlite3_snprintf()] interface writes a zero-terminated
**           UTF-8 string into the buffer pointed to by the second parameter
**           provided that the first parameter is greater than zero.
**
** {F17407}  The [sqlite3_snprintf()] interface does not writes slots of
**           its output buffer (the second parameter) outside the range
**           of 0 through N-1 (where N is the first parameter)
**           regardless of the length of the string
**           requested by the format specification.
**   
*/
SQLITE_API char *sqlite3_mprintf(const char*,...);
SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem {F17300}
**
** The SQLite core  uses these three routines for all of its own
** internal memory allocation needs. "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The
** windows VFS uses native malloc and free for some operations.
**
** The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.
**
** Calling sqlite3_free() with a pointer previously returned
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
** that it might be reused.  The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_free().
**
** The sqlite3_realloc() interface attempts to resize a
** prior memory allocation to be at least N bytes, where N is the
** second parameter.  The memory allocation to be resized is the first
** parameter.  If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** Sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** If M is the size of the prior allocation, then min(N,M) bytes
** of the prior allocation are copied into the beginning of buffer returned
** by sqlite3_realloc() and the prior allocation is freed.
** If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** The default implementation
** of the memory allocation subsystem uses the malloc(), realloc()
** and free() provided by the standard C library. {F17382} However, if 
** SQLite is compiled with the following C preprocessor macro
**
** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote>
**
** where <i>NNN</i> is an integer, then SQLite create a static
** array of at least <i>NNN</i> bytes in size and use that array
** for all of its dynamic memory allocation needs. {END}  Additional
** memory allocator options may be added in future releases.
**
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
** implementation of these routines to be omitted.  That capability
** is no longer provided.  Only built-in memory allocators can be
** used.
**
** The windows OS interface layer calls
** the system malloc() and free() directly when converting
** filenames between the UTF-8 encoding used by SQLite
** and whatever filename encoding is used by the particular windows
** installation.  Memory allocation errors are detected, but
** they are reported back as [SQLITE_CANTOPEN] or
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
**
** INVARIANTS:
**
** {F17303}  The [sqlite3_malloc(N)] interface returns either a pointer to 
**           newly checked-out block of at least N bytes of memory
**           that is 8-byte aligned, 
**           or it returns NULL if it is unable to fulfill the request.
**
** {F17304}  The [sqlite3_malloc(N)] interface returns a NULL pointer if
**           N is less than or equal to zero.
**
** {F17305}  The [sqlite3_free(P)] interface releases memory previously
**           returned from [sqlite3_malloc()] or [sqlite3_realloc()],
**           making it available for reuse.
**
** {F17306}  A call to [sqlite3_free(NULL)] is a harmless no-op.
**
** {F17310}  A call to [sqlite3_realloc(0,N)] is equivalent to a call
**           to [sqlite3_malloc(N)].
**
** {F17312}  A call to [sqlite3_realloc(P,0)] is equivalent to a call
**           to [sqlite3_free(P)].
**
** {F17315}  The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()],
**           and [sqlite3_free()] for all of its memory allocation and
**           deallocation needs.
**
** {F17318}  The [sqlite3_realloc(P,N)] interface returns either a pointer
**           to a block of checked-out memory of at least N bytes in size
**           that is 8-byte aligned, or a NULL pointer.
**
** {F17321}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           copies the first K bytes of content from P into the newly allocated
**           where K is the lessor of N and the size of the buffer P.
**
** {F17322}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           releases the buffer P.
**
** {F17323}  When [sqlite3_realloc(P,N)] returns NULL, the buffer P is
**           not modified or released.
**
** LIMITATIONS:
**
** {U17350}  The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
**           must be either NULL or else a pointer obtained from a prior
**           invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that has
**           not been released.
**
** {U17351}  The application must not read or write any part of 
**           a block of memory after it has been released using
**           [sqlite3_free()] or [sqlite3_realloc()].
**
*/
SQLITE_API void *sqlite3_malloc(int);
SQLITE_API void *sqlite3_realloc(void*, int);
SQLITE_API void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics {F17370}
**
** SQLite provides these two interfaces for reporting on the status
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
** the memory allocation subsystem included within the SQLite.
**
** INVARIANTS:
**
** {F17371} The [sqlite3_memory_used()] routine returns the
**          number of bytes of memory currently outstanding 
**          (malloced but not freed).
**
** {F17373} The [sqlite3_memory_highwater()] routine returns the maximum
**          value of [sqlite3_memory_used()] 
**          since the highwater mark was last reset.
**
** {F17374} The values returned by [sqlite3_memory_used()] and
**          [sqlite3_memory_highwater()] include any overhead
**          added by SQLite in its implementation of [sqlite3_malloc()],
**          but not overhead added by the any underlying system library
**          routines that [sqlite3_malloc()] may call.
** 
** {F17375} The memory highwater mark is reset to the current value of
**          [sqlite3_memory_used()] if and only if the parameter to
**          [sqlite3_memory_highwater()] is true.  The value returned
**          by [sqlite3_memory_highwater(1)] is the highwater mark
**          prior to the reset.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Pseudo-Random Number Generator {F17390}
**
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random ROWIDs when inserting new records into a table that
** already uses the largest possible ROWID.  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** appliations to access the same PRNG for other purposes.
**
** A call to this routine stores N bytes of randomness into buffer P.
**
** The first time this routine is invoked (either internally or by
** the application) the PRNG is seeded using randomness obtained
** from the xRandomness method of the default [sqlite3_vfs] object.
** On all subsequent invocations, the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.
**
** INVARIANTS:
**
** {F17392} The [sqlite3_randomness(N,P)] interface writes N bytes of
**          high-quality pseudo-randomness into buffer P.
*/
SQLITE_API void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks {F12500}
**
** This routine registers a authorizer callback with a particular
** [database connection], supplied in the first argument.
** The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  The authorizer callback should
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
** specific action but allow the SQL statement to continue to be
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
** rejected with an error.   If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer will fail with an error message.
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  When the callback returns [SQLITE_DENY], the
** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer will fail with an error message explaining that
** access is denied.  If the authorizer code is [SQLITE_READ]
** and the callback returns [SQLITE_IGNORE] then the
** [prepared statement] statement is constructed to substitute
** a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
** return can be used to deny an untrusted user access to individual
** columns of a table.
**
** The first parameter to the authorizer callback is a copy of
** the third parameter to the sqlite3_set_authorizer() interface.
** The second parameter to the callback is an integer 
** [SQLITE_COPY | action code] that specifies the particular action
** to be authorized. The third through sixth
** parameters to the callback are zero-terminated strings that contain 
** additional details about the action to be authorized.
**
** An authorizer is used when [sqlite3_prepare | preparing]
** SQL statements from an untrusted
** source, to ensure that the SQL statements do not try to access data
** that they are not allowed to see, or that they do not try to
** execute malicious statements that damage the database.  For
** example, an application may allow a user to enter arbitrary
** SQL queries for evaluation by a database.  But the application does
** not want the user to be able to make arbitrary changes to the
** database.  An authorizer could then be put in place while the
** user-entered SQL is being [sqlite3_prepare | prepared] that
** disallows everything except [SELECT] statements.
**
** Applications that need to process SQL from untrusted sources
** might also consider lowering resource limits using [sqlite3_limit()]
** and limiting database size using the [max_page_count] [PRAGMA]
** in addition to using an authorizer.
**
** Only a single authorizer can be in place on a database connection
** at a time.  Each call to sqlite3_set_authorizer overrides the
** previous call.  Disable the authorizer by installing a NULL callback.
** The authorizer is disabled by default.
**
** Note that the authorizer callback is invoked only during 
** [sqlite3_prepare()] or its variants.  Authorization is not
** performed during statement evaluation in [sqlite3_step()].
**
** INVARIANTS:
**
** {F12501} The [sqlite3_set_authorizer(D,...)] interface registers a
**          authorizer callback with database connection D.
**
** {F12502} The authorizer callback is invoked as SQL statements are
**          being compiled
**
** {F12503} If the authorizer callback returns any value other than
**          [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] then
**          the [sqlite3_prepare_v2()] or equivalent call that caused
**          the authorizer callback to run shall fail with an
**          [SQLITE_ERROR] error code and an appropriate error message.
**
** {F12504} When the authorizer callback returns [SQLITE_OK], the operation
**          described is coded normally.
**
** {F12505} When the authorizer callback returns [SQLITE_DENY], the
**          [sqlite3_prepare_v2()] or equivalent call that caused the
**          authorizer callback to run shall fail
**          with an [SQLITE_ERROR] error code and an error message
**          explaining that access is denied.
**
** {F12506} If the authorizer code (the 2nd parameter to the authorizer
**          callback) is [SQLITE_READ] and the authorizer callback returns
**          [SQLITE_IGNORE] then the prepared statement is constructed to
**          insert a NULL value in place of the table column that would have
**          been read if [SQLITE_OK] had been returned.
**
** {F12507} If the authorizer code (the 2nd parameter to the authorizer
**          callback) is anything other than [SQLITE_READ], then
**          a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 
**
** {F12510} The first parameter to the authorizer callback is a copy of
**          the third parameter to the [sqlite3_set_authorizer()] interface.
**
** {F12511} The second parameter to the callback is an integer 
**          [SQLITE_COPY | action code] that specifies the particular action
**          to be authorized.
**
** {F12512} The third through sixth parameters to the callback are
**          zero-terminated strings that contain 
**          additional details about the action to be authorized.
**
** {F12520} Each call to [sqlite3_set_authorizer()] overrides the
**          any previously installed authorizer.
**
** {F12521} A NULL authorizer means that no authorization
**          callback is invoked.
**
** {F12522} The default authorizer is NULL.
*/
SQLITE_API int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);

/*
** CAPI3REF: Authorizer Return Codes {F12590}
**
** The [sqlite3_set_authorizer | authorizer callback function] must
** return either [SQLITE_OK] or one of these two constants in order
** to signal SQLite whether or not the action is permitted.  See the
** [sqlite3_set_authorizer | authorizer documentation] for additional
** information.
*/
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

/*
** CAPI3REF: Authorizer Action Codes {F12550}
**
** The [sqlite3_set_authorizer()] interface registers a callback function
** that is invoked to authorizer certain SQL statement actions.  The
** second parameter to the callback is an integer code that specifies
** what action is being authorized.  These are the integer action codes that
** the authorizer callback may be passed.
**
** These action code values signify what kind of operation is to be 
** authorized.  The 3rd and 4th parameters to the authorization
** callback function will be parameters or NULL depending on which of these
** codes is used as the second parameter.  The 5th parameter to the
** authorizer callback is the name of the database ("main", "temp", 
** etc.) if applicable.  The 6th parameter to the authorizer callback
** is the name of the inner-most trigger or view that is responsible for
** the access attempt or NULL if this access attempt is directly from 
** top-level SQL code.
**
** INVARIANTS:
**
** {F12551} The second parameter to an 
**          [sqlite3_set_authorizer | authorizer callback is always an integer
**          [SQLITE_COPY | authorizer code] that specifies what action
**          is being authorized.
**
** {F12552} The 3rd and 4th parameters to the 
**          [sqlite3_set_authorizer | authorization callback function]
**          will be parameters or NULL depending on which 
**          [SQLITE_COPY | authorizer code] is used as the second parameter.
**
** {F12553} The 5th parameter to the
**          [sqlite3_set_authorizer | authorizer callback] is the name
**          of the database (example: "main", "temp", etc.) if applicable.
**
** {F12554} The 6th parameter to the
**          [sqlite3_set_authorizer | authorizer callback] is the name
**          of the inner-most trigger or view that is responsible for
**          the access attempt or NULL if this access attempt is directly from 
**          top-level SQL code.
*/
/******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
#define SQLITE_DELETE                9   /* Table Name      NULL            */
#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
#define SQLITE_INSERT               18   /* Table Name      NULL            */
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
#define SQLITE_READ                 20   /* Table Name      Column Name     */
#define SQLITE_SELECT               21   /* NULL            NULL            */
#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */
#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* Function Name   NULL            */
#define SQLITE_COPY                  0   /* No longer used */

/*
** CAPI3REF: Tracing And Profiling Functions {F12280}
**
** These routines register callback functions that can be used for
** tracing and profiling the execution of SQL statements.
**
** The callback function registered by sqlite3_trace() is invoked at
** various times when an SQL statement is being run by [sqlite3_step()].
** The callback returns a UTF-8 rendering of the SQL statement text
** as the statement first begins executing.  Additional callbacks occur
** as each triggersubprogram is entered.  The callbacks for triggers
** contain a UTF-8 SQL comment that identifies the trigger.
** 
** The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.
**
** The sqlite3_profile() API is currently considered experimental and
** is subject to change or removal in a future release.
**
** The trigger reporting feature of the trace callback is considered
** experimental and is subject to change or removal in future releases.
** Future versions of SQLite might also add new trace callback 
** invocations.
**
** INVARIANTS:
**
** {F12281} The callback function registered by [sqlite3_trace()] is
**          whenever an SQL statement first begins to execute and
**          whenever a trigger subprogram first begins to run.
**
** {F12282} Each call to [sqlite3_trace()] overrides the previously
**          registered trace callback.
**
** {F12283} A NULL trace callback disables tracing.
**
** {F12284} The first argument to the trace callback is a copy of
**          the pointer which was the 3rd argument to [sqlite3_trace()].
**
** {F12285} The second argument to the trace callback is a
**          zero-terminated UTF8 string containing the original text
**          of the SQL statement as it was passed into [sqlite3_prepare_v2()]
**          or the equivalent, or an SQL comment indicating the beginning
**          of a trigger subprogram.
**
** {F12287} The callback function registered by [sqlite3_profile()] is invoked
**          as each SQL statement finishes.
**
** {F12288} The first parameter to the profile callback is a copy of
**          the 3rd parameter to [sqlite3_profile()].
**
** {F12289} The second parameter to the profile callback is a
**          zero-terminated UTF-8 string that contains the complete text of
**          the SQL statement as it was processed by [sqlite3_prepare_v2()]
**          or the equivalent.
**
** {F12290} The third parameter to the profile  callback is an estimate
**          of the number of nanoseconds of wall-clock time required to
**          run the SQL statement from start to finish.
*/
SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
SQLITE_API void *sqlite3_profile(sqlite3*,
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

/*
** CAPI3REF: Query Progress Callbacks {F12910}
**
** This routine configures a callback function - the
** progress callback - that is invoked periodically during long
** running calls to [sqlite3_exec()], [sqlite3_step()] and
** [sqlite3_get_table()].   An example use for this 
** interface is to keep a GUI updated during a large query.
**
** If the progress callback returns non-zero, the opertion is
** interrupted.  This feature can be used to implement a
** "Cancel" button on a GUI dialog box.
**
** INVARIANTS:
**
** {F12911} The callback function registered by [sqlite3_progress_handler()]
**          is invoked periodically during long running calls to
**          [sqlite3_step()].
**
** {F12912} The progress callback is invoked once for every N virtual
**          machine opcodes, where N is the second argument to 
**          the [sqlite3_progress_handler()] call that registered
**          the callback.  <todo>What if N is less than 1?</todo>
**
** {F12913} The progress callback itself is identified by the third
**          argument to [sqlite3_progress_handler()].
**
** {F12914} The fourth argument [sqlite3_progress_handler()] is a
***         void pointer passed to the progress callback
**          function each time it is invoked.
**
** {F12915} If a call to [sqlite3_step()] results in fewer than
**          N opcodes being executed,
**          then the progress callback is never invoked. {END}
** 
** {F12916} Every call to [sqlite3_progress_handler()]
**          overwrites any previously registere progress handler.
**
** {F12917} If the progress handler callback is NULL then no progress
**          handler is invoked.
**
** {F12918} If the progress callback returns a result other than 0, then
**          the behavior is a if [sqlite3_interrupt()] had been called.
*/
SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

/*
** CAPI3REF: Opening A New Database Connection {F12700}
**
** These routines open an SQLite database file whose name
** is given by the filename argument.
** The filename argument is interpreted as UTF-8
** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16
** in the native byte order for [sqlite3_open16()].
** An [sqlite3*] handle is usually returned in *ppDb, even
** if an error occurs.  The only exception is if SQLite is unable
** to allocate memory to hold the [sqlite3] object, a NULL will
** be written into *ppDb instead of a pointer to the [sqlite3] object.
** If the database is opened (and/or created)
** successfully, then [SQLITE_OK] is returned.  Otherwise an
** error code is returned.  The
** [sqlite3_errmsg()] or [sqlite3_errmsg16()]  routines can be used to obtain
** an English language description of the error.
**
** The default encoding for the database will be UTF-8 if
** [sqlite3_open()] or [sqlite3_open_v2()] is called and
** UTF-16 in the native byte order if [sqlite3_open16()] is used.
**
** Whether or not an error occurs when it is opened, resources
** associated with the [sqlite3*] handle should be released by passing it
** to [sqlite3_close()] when it is no longer required.
**
** The [sqlite3_open_v2()] interface works like [sqlite3_open()] 
** except that it acccepts two additional parameters for additional control
** over the new database connection.  The flags parameter can be
** one of:
**
** <ol>
** <li>  [SQLITE_OPEN_READONLY]
** <li>  [SQLITE_OPEN_READWRITE]
** <li>  [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
** </ol>
**
** The first value opens the database read-only. 
** If the database does not previously exist, an error is returned.
** The second option opens
** the database for reading and writing if possible, or reading only if
** if the file is write protected.  In either case the database
** must already exist or an error is returned.  The third option
** opens the database for reading and writing and creates it if it does
** not already exist.
** The third options is behavior that is always used for [sqlite3_open()]
** and [sqlite3_open16()].
**
** If the 3rd parameter to [sqlite3_open_v2()] is not one of the
** combinations shown above then the behavior is undefined.
**
** If the filename is ":memory:", then an private
** in-memory database is created for the connection.  This in-memory
** database will vanish when the database connection is closed.  Future
** version of SQLite might make use of additional special filenames
** that begin with the ":" character.  It is recommended that 
** when a database filename really does begin with
** ":" that you prefix the filename with a pathname like "./" to
** avoid ambiguity.
**
** If the filename is an empty string, then a private temporary
** on-disk database will be created.  This private database will be
** automatically deleted as soon as the database connection is closed.
**
** The fourth parameter to sqlite3_open_v2() is the name of the
** [sqlite3_vfs] object that defines the operating system 
** interface that the new database connection should use.  If the
** fourth parameter is a NULL pointer then the default [sqlite3_vfs]
** object is used.
**
** <b>Note to windows users:</b>  The encoding used for the filename argument
** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever
** codepage is currently defined.  Filenames containing international
** characters must be converted to UTF-8 prior to passing them into
** [sqlite3_open()] or [sqlite3_open_v2()].
**
** INVARIANTS:
**
** {F12701} The [sqlite3_open()], [sqlite3_open16()], and
**          [sqlite3_open_v2()] interfaces create a new
**          [database connection] associated with
**          the database file given in their first parameter.
**
** {F12702} The filename argument is interpreted as UTF-8
**          for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16
**          in the native byte order for [sqlite3_open16()].
**
** {F12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()], 
**          or [sqlite3_open_v2()] writes a pointer to a new
**          [database connection] into *ppDb.
**
** {F12704} The [sqlite3_open()], [sqlite3_open16()], and
**          [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success,
**          or an appropriate [error code] on failure.
**
** {F12706} The default text encoding for a new database created using
**          [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8.
**
** {F12707} The default text encoding for a new database created using
**          [sqlite3_open16()] will be UTF-16.
**
** {F12709} The [sqlite3_open(F,D)] interface is equivalent to
**          [sqlite3_open_v2(F,D,G,0)] where the G parameter is
**          [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE].
**
** {F12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the
**          bit value [SQLITE_OPEN_READONLY] then the database is opened
**          for reading only.
**
** {F12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the
**          bit value [SQLITE_OPEN_READWRITE] then the database is opened
**          reading and writing if possible, or for reading only if the
**          file is write protected by the operating system.
**
** {F12713} If the G parameter to [sqlite3_open(v2(F,D,G,V)] omits the
**          bit value [SQLITE_OPEN_CREATE] and the database does not
**          previously exist, an error is returned.
**
** {F12714} If the G parameter to [sqlite3_open(v2(F,D,G,V)] contains the
**          bit value [SQLITE_OPEN_CREATE] and the database does not
**          previously exist, then an attempt is made to create and
**          initialize the database.
**
** {F12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()],
**          or [sqlite3_open_v2()] is ":memory:", then an private,
**          ephemeral, in-memory database is created for the connection.
**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
**          in sqlite3_open_v2()?</todo>
**
** {F12719} If the filename is NULL or an empty string, then a private,
**          ephermeral on-disk database will be created.
**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
**          in sqlite3_open_v2()?</todo>
**
** {F12721} The [database connection] created by 
**          [sqlite3_open_v2(F,D,G,V)] will use the
**          [sqlite3_vfs] object identified by the V parameter, or
**          the default [sqlite3_vfs] object is V is a NULL pointer.
*/
SQLITE_API int sqlite3_open(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb          /* OUT: SQLite db handle */
);
SQLITE_API int sqlite3_open16(
  const void *filename,   /* Database filename (UTF-16) */
  sqlite3 **ppDb          /* OUT: SQLite db handle */
);
SQLITE_API int sqlite3_open_v2(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  int flags,              /* Flags */
  const char *zVfs        /* Name of VFS module to use */
);

/*
** CAPI3REF: Error Codes And Messages {F12800}
**
** The sqlite3_errcode() interface returns the numeric
** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
** for the most recent failed sqlite3_* API call associated
** with [sqlite3] handle 'db'. If a prior API call failed but the
** most recent API call succeeded, the return value from sqlite3_errcode()
** is undefined.
**
** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF8 or UTF16 respectively.
** Memory to hold the error message string is managed internally.
** The application does not need to worry with freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.
**
** INVARIANTS:
**
** {F12801} The [sqlite3_errcode(D)] interface returns the numeric
**          [SQLITE_OK | result code] or
**          [SQLITE_IOERR_READ | extended result code]
**          for the most recently failed interface call associated
**          with [database connection] D.
**
** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
**          interfaces return English-language text that describes
**          the error in the mostly recently failed interface call,
**          encoded as either UTF8 or UTF16 respectively.
**
** {F12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
**          are valid until the next SQLite interface call.
**
** {F12808} Calls to API routines that do not return an error code
**          (example: [sqlite3_data_count()]) do not
**          change the error code or message returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**
** {F12809} Interfaces that are not associated with a specific
**          [database connection] (examples:
**          [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()]
**          do not change the values returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
*/
SQLITE_API int sqlite3_errcode(sqlite3 *db);
SQLITE_API const char *sqlite3_errmsg(sqlite3*);
SQLITE_API const void *sqlite3_errmsg16(sqlite3*);

/*
** CAPI3REF: SQL Statement Object {F13000}
** KEYWORDS: {prepared statement} {prepared statements}
**
** An instance of this object represent single SQL statements.  This
** object is variously known as a "prepared statement" or a 
** "compiled SQL statement" or simply as a "statement".
** 
** The life of a statement object goes something like this:
**
** <ol>
** <li> Create the object using [sqlite3_prepare_v2()] or a related
**      function.
** <li> Bind values to host parameters using
**      [sqlite3_bind_blob | sqlite3_bind_* interfaces].
** <li> Run the SQL by calling [sqlite3_step()] one or more times.
** <li> Reset the statement using [sqlite3_reset()] then go back
**      to step 2.  Do this zero or more times.
** <li> Destroy the object using [sqlite3_finalize()].
** </ol>
**
** Refer to documentation on individual methods above for additional
** information.
*/
typedef struct sqlite3_stmt sqlite3_stmt;

/*
** CAPI3REF: Run-time Limits {F12760}
**
** This interface allows the size of various constructs to be limited
** on a connection by connection basis.  The first parameter is the
** [database connection] whose limit is to be set or queried.  The
** second parameter is one of the [limit categories] that define a
** class of constructs to be size limited.  The third parameter is the
** new limit for that construct.  The function returns the old limit.
**
** If the new limit is a negative number, the limit is unchanged.
** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper
** bound set by a compile-time C-preprocess macro named SQLITE_MAX_XYZ.
** (The "_LIMIT_" in the name is changed to "_MAX_".)
** Attempts to increase a limit above its hard upper bound are
** silently truncated to the hard upper limit.
**
** Run time limits are intended for use in applications that manage
** both their own internal database and also databases that are controlled
** by untrusted external sources.  An example application might be a
** webbrowser that has its own databases for storing history and
** separate databases controlled by javascript applications downloaded
** off the internet.  The internal databases can be given the
** large, default limits.  Databases managed by external sources can
** be given much smaller limits designed to prevent a denial of service
** attach.  Developers might also want to use the [sqlite3_set_authorizer()]
** interface to further control untrusted SQL.  The size of the database
** created by an untrusted script can be contained using the
** [max_page_count] [PRAGMA].
**
** This interface is currently considered experimental and is subject
** to change or removal without prior notice.
**
** INVARIANTS:
**
** {F12762} A successful call to [sqlite3_limit(D,C,V)] where V is
**          positive changes the
**          limit on the size of construct C in [database connection] D
**          to the lessor of V and the hard upper bound on the size
**          of C that is set at compile-time.
**
** {F12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative
**          leaves the state of [database connection] D unchanged.
**
** {F12769} A successful call to [sqlite3_limit(D,C,V)] returns the
**          value of the limit on the size of construct C in
**          in [database connection] D as it was prior to the call.
*/
SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);

/*
** CAPI3REF: Run-Time Limit Categories {F12790}
** KEYWORDS: {limit category} {limit categories}
** 
** These constants define various aspects of a [database connection]
** that can be limited in size by calls to [sqlite3_limit()].
** The meanings of the various limits are as follows:
**
** <dl>
** <dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any
** string or blob or table row.<dd>
**
** <dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_COLUMN</dt>
** <dd>The maximum number of columns in a table definition or in the
** result set of a SELECT or the maximum number of columns in an index
** or in an ORDER BY or GROUP BY clause.</dd>
**
** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
** <dd>The maximum depth of the parse tree on any expression.</dd>
**
** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
** <dd>The maximum number of terms in a compound SELECT statement.</dd>
**
** <dt>SQLITE_LIMIT_VDBE_OP</dt>
** <dd>The maximum number of instructions in a virtual machine program
** used to implement an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
** <dd>The maximum number of arguments on a function.</dd>
**
** <dt>SQLITE_LIMIT_ATTACHED</dt>
** <dd>The maximum number of attached databases.</dd>
**
** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
** <dd>The maximum length of the pattern argument to the LIKE or
** GLOB operators.</dd>
**
** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
** <dd>The maximum number of variables in an SQL statement that can
** be bound.</dd>
** </dl>
*/
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
#define SQLITE_LIMIT_VDBE_OP                   5
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9

/*
** CAPI3REF: Compiling An SQL Statement {F13010}
**
** To execute an SQL query, it must first be compiled into a byte-code
** program using one of these routines. 
**
** The first argument "db" is an [database connection] 
** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()]
** or [sqlite3_open16()]. 
** The second argument "zSql" is the statement to be compiled, encoded
** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
** use UTF-16. {END}
**
** If the nByte argument is less
** than zero, then zSql is read up to the first zero terminator.
** If nByte is non-negative, then it is the maximum number of 
** bytes read from zSql.  When nByte is non-negative, the
** zSql string ends at either the first '\000' or '\u0000' character or 
** the nByte-th byte, whichever comes first. If the caller knows
** that the supplied string is nul-terminated, then there is a small
** performance advantage to be had by passing an nByte parameter that 
** is equal to the number of bytes in the input string <i>including</i> 
** the nul-terminator bytes.{END}
**
** *pzTail is made to point to the first byte past the end of the
** first SQL statement in zSql.  These routines only compiles the first
** statement in zSql, so *pzTail is left pointing to what remains
** uncompiled.
**
** *ppStmt is left pointing to a compiled [prepared statement] that can be
** executed using [sqlite3_step()].  Or if there is an error, *ppStmt is
** set to NULL.  If the input text contains no SQL (if the input
** is and empty string or a comment) then *ppStmt is set to NULL.
** {U13018} The calling procedure is responsible for deleting the
** compiled SQL statement
** using [sqlite3_finalize()] after it has finished with it.
**
** On success, [SQLITE_OK] is returned.  Otherwise an 
** [error code] is returned.
**
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
** recommended for all new programs. The two older interfaces are retained
** for backwards compatibility, but their use is discouraged.
** In the "v2" interfaces, the prepared statement
** that is returned (the [sqlite3_stmt] object) contains a copy of the 
** original SQL text. {END} This causes the [sqlite3_step()] interface to
** behave a differently in two ways:
**
** <ol>
** <li>
** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
** always used to do, [sqlite3_step()] will automatically recompile the SQL
** statement and try to run it again.  If the schema has changed in
** a way that makes the statement no longer valid, [sqlite3_step()] will still
** return [SQLITE_SCHEMA].  But unlike the legacy behavior, 
** [SQLITE_SCHEMA] is now a fatal error.  Calling
** [sqlite3_prepare_v2()] again will not make the
** error go away.  Note: use [sqlite3_errmsg()] to find the text
** of the parsing error that results in an [SQLITE_SCHEMA] return. {END}
** </li>
**
** <li>
** When an error occurs, 
** [sqlite3_step()] will return one of the detailed 
** [error codes] or [extended error codes]. 
** The legacy behavior was that [sqlite3_step()] would only return a generic
** [SQLITE_ERROR] result code and you would have to make a second call to
** [sqlite3_reset()] in order to find the underlying cause of the problem.
** With the "v2" prepare interfaces, the underlying reason for the error is
** returned immediately.
** </li>
** </ol>
**
** INVARIANTS:
**
** {F13011} The [sqlite3_prepare(db,zSql,...)] and
**          [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the
**          text in their zSql parameter as UTF-8.
**
** {F13012} The [sqlite3_prepare16(db,zSql,...)] and
**          [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the
**          text in their zSql parameter as UTF-16 in the native byte order.
**
** {F13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
**          and its variants is less than zero, then SQL text is
**          read from zSql is read up to the first zero terminator.
**
** {F13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
**          and its variants is non-negative, then at most nBytes bytes
**          SQL text is read from zSql.
**
** {F13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants
**          if the zSql input text contains more than one SQL statement
**          and pzTail is not NULL, then *pzTail is made to point to the
**          first byte past the end of the first SQL statement in zSql.
**          <todo>What does *pzTail point to if there is one statement?</todo>
**
** {F13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)]
**          or one of its variants writes into *ppStmt a pointer to a new
**          [prepared statement] or a pointer to NULL
**          if zSql contains nothing other than whitespace or comments. 
**
** {F13019} The [sqlite3_prepare_v2()] interface and its variants return
**          [SQLITE_OK] or an appropriate [error code] upon failure.
**
** {F13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its
**          variants returns an error (any value other than [SQLITE_OK])
**          it first sets *ppStmt to NULL.
*/
SQLITE_API int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
);
SQLITE_API int sqlite3_prepare_v2(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
);
SQLITE_API int sqlite3_prepare16(
  sqlite3 *db,            /* Database handle */
  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);
SQLITE_API int sqlite3_prepare16_v2(
  sqlite3 *db,            /* Database handle */
  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);

/*
** CAPIREF: Retrieving Statement SQL {F13100}
**
** This intereface can be used to retrieve a saved copy of the original
** SQL text used to create a [prepared statement].
**
** INVARIANTS:
**
** {F13101} If the [prepared statement] passed as 
**          the an argument to [sqlite3_sql()] was compiled
**          compiled using either [sqlite3_prepare_v2()] or
**          [sqlite3_prepare16_v2()],
**          then [sqlite3_sql()] function returns a pointer to a
**          zero-terminated string containing a UTF-8 rendering
**          of the original SQL statement.
**
** {F13102} If the [prepared statement] passed as 
**          the an argument to [sqlite3_sql()] was compiled
**          compiled using either [sqlite3_prepare()] or
**          [sqlite3_prepare16()],
**          then [sqlite3_sql()] function returns a NULL pointer.
**
** {F13103} The string returned by [sqlite3_sql(S)] is valid until the
**          [prepared statement] S is deleted using [sqlite3_finalize(S)].
*/
SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF:  Dynamically Typed Value Object  {F15000}
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**
** SQLite uses the sqlite3_value object to represent all values
** that can be stored in a database table.
** SQLite uses dynamic typing for the values it stores.  
** Values stored in sqlite3_value objects can be
** be integers, floating point values, strings, BLOBs, or NULL.
**
** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies 
** whether or not it requires a protected sqlite3_value.
**
** The terms "protected" and "unprotected" refer to whether or not
** a mutex is held.  A internal mutex is held for a protected
** sqlite3_value object but no mutex is held for an unprotected
** sqlite3_value object.  If SQLite is compiled to be single-threaded
** (with SQLITE_THREADSAFE=0 and with [sqlite3_threadsafe()] returning 0)
** then there is no distinction between
** protected and unprotected sqlite3_value objects and they can be
** used interchangable.  However, for maximum code portability it
** is recommended that applications make the distinction between
** between protected and unprotected sqlite3_value objects even if
** they are single threaded.
**
** The sqlite3_value objects that are passed as parameters into the
** implementation of application-defined SQL functions are protected.
** The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used with
** [sqlite3_result_value()] and [sqlite3_bind_value()].  All other
** interfaces that use sqlite3_value require protected sqlite3_value objects.
*/
typedef struct Mem sqlite3_value;

/*
** CAPI3REF:  SQL Function Context Object {F16001}
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  A pointer to an sqlite3_context
** object is always first parameter to application-defined SQL functions.
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF:  Binding Values To Prepared Statements {F13500}
**
** In the SQL strings input to [sqlite3_prepare_v2()] and its
** variants, literals may be replace by a parameter in one
** of these forms:
**
** <ul>
** <li>  ?
** <li>  ?NNN
** <li>  :VVV
** <li>  @VVV
** <li>  $VVV
** </ul>
**
** In the parameter forms shown above NNN is an integer literal,
** VVV alpha-numeric parameter name.
** The values of these parameters (also called "host parameter names"
** or "SQL parameters")
** can be set using the sqlite3_bind_*() routines defined here.
**
** The first argument to the sqlite3_bind_*() routines always
** is a pointer to the [sqlite3_stmt] object returned from
** [sqlite3_prepare_v2()] or its variants. The second
** argument is the index of the parameter to be set. The
** first parameter has an index of 1.  When the same named
** parameter is used more than once, second and subsequent
** occurrences have the same index as the first occurrence. 
** The index for named parameters can be looked up using the
** [sqlite3_bind_parameter_name()] API if desired.  The index
** for "?NNN" parameters is the value of NNN.
** The NNN value must be between 1 and the compile-time
** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
**
** The third argument is the value to bind to the parameter.
**
** In those
** routines that have a fourth argument, its value is the number of bytes
** in the parameter.  To be clear: the value is the number of <u>bytes</u>
** in the value, not the number of characters. 
** If the fourth parameter is negative, the length of the string is
** number of bytes up to the first zero terminator.
**
** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
** string after SQLite has finished with it. If the fifth argument is
** the special value [SQLITE_STATIC], then SQLite assumes that the
** information is in static, unmanaged space and does not need to be freed.
** If the fifth argument has the value [SQLITE_TRANSIENT], then
** SQLite makes its own private copy of the data immediately, before
** the sqlite3_bind_*() routine returns.
**
** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
** is filled with zeros.  A zeroblob uses a fixed amount of memory
** (just an integer to hold it size) while it is being processed.
** Zeroblobs are intended to serve as place-holders for BLOBs whose
** content is later written using 
** [sqlite3_blob_open | increment BLOB I/O] routines. A negative
** value for the zeroblob results in a zero-length BLOB.
**
** The sqlite3_bind_*() routines must be called after
** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
** before [sqlite3_step()].
** Bindings are not cleared by the [sqlite3_reset()] routine.
** Unbound parameters are interpreted as NULL.
**
** These routines return [SQLITE_OK] on success or an error code if
** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter
** index is out of range.  [SQLITE_NOMEM] is returned if malloc fails.
** [SQLITE_MISUSE] might be returned if these routines are called on a
** virtual machine that is the wrong state or which has already been finalized.
** Detection of misuse is unreliable.  Applications should not depend
** on SQLITE_MISUSE returns.  SQLITE_MISUSE is intended to indicate a
** a logic error in the application.  Future versions of SQLite might
** panic rather than return SQLITE_MISUSE.
**
** See also: [sqlite3_bind_parameter_count()],
** [sqlite3_bind_parameter_name()], and
** [sqlite3_bind_parameter_index()].
**
** INVARIANTS:
**
** {F13506} The [sqlite3_prepare | SQL statement compiler] recognizes
**          tokens of the forms "?", "?NNN", "$VVV", ":VVV", and "@VVV"
**          as SQL parameters, where NNN is any sequence of one or more
**          digits and where VVV is any sequence of one or more 
**          alphanumeric characters or "::" optionally followed by
**          a string containing no spaces and contained within parentheses.
**
** {F13509} The initial value of an SQL parameter is NULL.
**
** {F13512} The index of an "?" SQL parameter is one larger than the
**          largest index of SQL parameter to the left, or 1 if
**          the "?" is the leftmost SQL parameter.
**
** {F13515} The index of an "?NNN" SQL parameter is the integer NNN.
**
** {F13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is
**          the same as the index of leftmost occurances of the same
**          parameter, or one more than the largest index over all
**          parameters to the left if this is the first occurrance
**          of this parameter, or 1 if this is the leftmost parameter.
**
** {F13521} The [sqlite3_prepare | SQL statement compiler] fail with
**          an [SQLITE_RANGE] error if the index of an SQL parameter
**          is less than 1 or greater than SQLITE_MAX_VARIABLE_NUMBER.
**
** {F13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)]
**          associate the value V with all SQL parameters having an
**          index of N in the [prepared statement] S.
**
** {F13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)]
**          override prior calls with the same values of S and N.
**
** {F13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)]
**          persist across calls to [sqlite3_reset(S)].
**
** {F13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
**          [sqlite3_bind_text(S,N,V,L,D)], or
**          [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L
**          bytes of the blob or string pointed to by V, when L
**          is non-negative.
**
** {F13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or
**          [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters
**          from V through the first zero character when L is negative.
**
** {F13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
**          [sqlite3_bind_text(S,N,V,L,D)], or
**          [sqlite3_bind_text16(S,N,V,L,D)] when D is the special
**          constant [SQLITE_STATIC], SQLite assumes that the value V
**          is held in static unmanaged space that will not change
**          during the lifetime of the binding.
**
** {F13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
**          [sqlite3_bind_text(S,N,V,L,D)], or
**          [sqlite3_bind_text16(S,N,V,L,D)] when D is the special
**          constant [SQLITE_TRANSIENT], the routine makes a 
**          private copy of V value before it returns.
**
** {F13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
**          [sqlite3_bind_text(S,N,V,L,D)], or
**          [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to
**          a function, SQLite invokes that function to destroy the
**          V value after it has finished using the V value.
**
** {F13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound
**          is a blob of L bytes, or a zero-length blob if L is negative.
**
** {F13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may
**          be either a [protected sqlite3_value] object or an
**          [unprotected sqlite3_value] object.
*/
SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

/*
** CAPI3REF: Number Of SQL Parameters {F13600}
**
** This routine can be used to find the number of SQL parameters
** in a prepared statement.  SQL parameters are tokens of the
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
** place-holders for values that are [sqlite3_bind_blob | bound]
** to the parameters at a later time.
**
** This routine actually returns the index of the largest parameter.
** For all forms except ?NNN, this will correspond to the number of
** unique parameters.  If parameters of the ?NNN are used, there may
** be gaps in the list.
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_name()], and
** [sqlite3_bind_parameter_index()].
**
** INVARIANTS:
**
** {F13601} The [sqlite3_bind_parameter_count(S)] interface returns
**          the largest index of all SQL parameters in the
**          [prepared statement] S, or 0 if S
**          contains no SQL parameters.
*/
SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);

/*
** CAPI3REF: Name Of A Host Parameter {F13620}
**
** This routine returns a pointer to the name of the n-th
** SQL parameter in a [prepared statement].
** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
** respectively.
** In other words, the initial ":" or "$" or "@" or "?"
** is included as part of the name.
** Parameters of the form "?" without a following integer have no name.
**
** The first host parameter has an index of 1, not 0.
**
** If the value n is out of range or if the n-th parameter is
** nameless, then NULL is returned.  The returned string is
** always in the UTF-8 encoding even if the named parameter was
** originally specified as UTF-16 in [sqlite3_prepare16()] or
** [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].
**
** INVARIANTS:
**
** {F13621} The [sqlite3_bind_parameter_name(S,N)] interface returns
**          a UTF-8 rendering of the name of the SQL parameter in
**          [prepared statement] S having index N, or
**          NULL if there is no SQL parameter with index N or if the
**          parameter with index N is an anonymous parameter "?".
*/
SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

/*
** CAPI3REF: Index Of A Parameter With A Given Name {F13640}
**
** Return the index of an SQL parameter given its name.  The
** index value returned is suitable for use as the second
** parameter to [sqlite3_bind_blob|sqlite3_bind()].  A zero
** is returned if no matching parameter is found.  The parameter
** name must be given in UTF-8 even if the original statement
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].
**
** INVARIANTS:
**
** {F13641} The [sqlite3_bind_parameter_index(S,N)] interface returns
**          the index of SQL parameter in [prepared statement]
**          S whose name matches the UTF-8 string N, or 0 if there is
**          no match.
*/
SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);

/*
** CAPI3REF: Reset All Bindings On A Prepared Statement {F13660}
**
** Contrary to the intuition of many, [sqlite3_reset()] does not
** reset the [sqlite3_bind_blob | bindings] on a 
** [prepared statement].  Use this routine to
** reset all host parameters to NULL.
**
** INVARIANTS:
**
** {F13661} The [sqlite3_clear_bindings(S)] interface resets all
**          SQL parameter bindings in [prepared statement] S
**          back to NULL.
*/
SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);

/*
** CAPI3REF: Number Of Columns In A Result Set {F13710}
**
** Return the number of columns in the result set returned by the 
** [prepared statement]. This routine returns 0
** if pStmt is an SQL statement that does not return data (for 
** example an UPDATE).
**
** INVARIANTS:
**
** {F13711} The [sqlite3_column_count(S)] interface returns the number of
**          columns in the result set generated by the
**          [prepared statement] S, or 0 if S does not generate
**          a result set.
*/
SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Column Names In A Result Set {F13720}
**
** These routines return the name assigned to a particular column
** in the result set of a SELECT statement.  The sqlite3_column_name()
** interface returns a pointer to a zero-terminated UTF8 string
** and sqlite3_column_name16() returns a pointer to a zero-terminated
** UTF16 string.  The first parameter is the
** [prepared statement] that implements the SELECT statement.
** The second parameter is the column number.  The left-most column is
** number 0.
**
** The returned string pointer is valid until either the 
** [prepared statement] is destroyed by [sqlite3_finalize()]
** or until the next call sqlite3_column_name() or sqlite3_column_name16()
** on the same column.
**
** If sqlite3_malloc() fails during the processing of either routine
** (for example during a conversion from UTF-8 to UTF-16) then a
** NULL pointer is returned.
**
** The name of a result column is the value of the "AS" clause for
** that column, if there is an AS clause.  If there is no AS clause
** then the name of the column is unspecified and may change from
** one release of SQLite to the next.
**
** INVARIANTS:
**
** {F13721} A successful invocation of the [sqlite3_column_name(S,N)]
**          interface returns the name
**          of the Nth column (where 0 is the left-most column) for the
**          result set of [prepared statement] S as a
**          zero-terminated UTF-8 string.
**
** {F13723} A successful invocation of the [sqlite3_column_name16(S,N)]
**          interface returns the name
**          of the Nth column (where 0 is the left-most column) for the
**          result set of [prepared statement] S as a
**          zero-terminated UTF-16 string in the native byte order.
**
** {F13724} The [sqlite3_column_name()] and [sqlite3_column_name16()]
**          interfaces return a NULL pointer if they are unable to
**          allocate memory memory to hold there normal return strings.
**
** {F13725} If the N parameter to [sqlite3_column_name(S,N)] or
**          [sqlite3_column_name16(S,N)] is out of range, then the
**          interfaces returns a NULL pointer.
** 
** {F13726} The strings returned by [sqlite3_column_name(S,N)] and
**          [sqlite3_column_name16(S,N)] are valid until the next
**          call to either routine with the same S and N parameters
**          or until [sqlite3_finalize(S)] is called.
**
** {F13727} When a result column of a [SELECT] statement contains
**          an AS clause, the name of that column is the indentifier
**          to the right of the AS keyword.
*/
SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);

/*
** CAPI3REF: Source Of Data In A Query Result {F13740}
**
** These routines provide a means to determine what column of what
** table in which database a result of a SELECT statement comes from.
** The name of the database or table or column can be returned as
** either a UTF8 or UTF16 string.  The _database_ routines return
** the database name, the _table_ routines return the table name, and
** the origin_ routines return the column name.
** The returned string is valid until
** the [prepared statement] is destroyed using
** [sqlite3_finalize()] or until the same information is requested
** again in a different encoding.
**
** The names returned are the original un-aliased names of the
** database, table, and column.
**
** The first argument to the following calls is a [prepared statement].
** These functions return information about the Nth column returned by 
** the statement, where N is the second function argument.
**
** If the Nth column returned by the statement is an expression
** or subquery and is not a column value, then all of these functions
** return NULL.  These routine might also return NULL if a memory
** allocation error occurs.  Otherwise, they return the 
** name of the attached database, table and column that query result
** column was extracted from.
**
** As with all other SQLite APIs, those postfixed with "16" return
** UTF-16 encoded strings, the other functions return UTF-8. {END}
**
** These APIs are only available if the library was compiled with the 
** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
**
** {U13751}
** If two or more threads call one or more of these routines against the same
** prepared statement and column at the same time then the results are
** undefined.
**
** INVARIANTS:
**
** {F13741} The [sqlite3_column_database_name(S,N)] interface returns either
**          the UTF-8 zero-terminated name of the database from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13742} The [sqlite3_column_database_name16(S,N)] interface returns either
**          the UTF-16 native byte order
**          zero-terminated name of the database from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13743} The [sqlite3_column_table_name(S,N)] interface returns either
**          the UTF-8 zero-terminated name of the table from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13744} The [sqlite3_column_table_name16(S,N)] interface returns either
**          the UTF-16 native byte order
**          zero-terminated name of the table from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13745} The [sqlite3_column_origin_name(S,N)] interface returns either
**          the UTF-8 zero-terminated name of the table column from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13746} The [sqlite3_column_origin_name16(S,N)] interface returns either
**          the UTF-16 native byte order
**          zero-terminated name of the table column from which the 
**          Nth result column of [prepared statement] S 
**          is extracted, or NULL if the the Nth column of S is a
**          general expression or if unable to allocate memory
**          to store the name.
**          
** {F13748} The return values from
**          [sqlite3_column_database_name|column metadata interfaces]
**          are valid
**          for the lifetime of the [prepared statement]
**          or until the encoding is changed by another metadata
**          interface call for the same prepared statement and column.
**
** LIMITATIONS:
**
** {U13751} If two or more threads call one or more
**          [sqlite3_column_database_name|column metadata interfaces]
**          the same [prepared statement] and result column
**          at the same time then the results are undefined.
*/
SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

/*
** CAPI3REF: Declared Datatype Of A Query Result {F13760}
**
** The first parameter is a [prepared statement]. 
** If this statement is a SELECT statement and the Nth column of the 
** returned result set of that SELECT is a table column (not an
** expression or subquery) then the declared type of the table
** column is returned.  If the Nth column of the result set is an
** expression or subquery, then a NULL pointer is returned.
** The returned string is always UTF-8 encoded.  {END} 
** For example, in the database schema:
**
** CREATE TABLE t1(c1 VARIANT);
**
** And the following statement compiled:
**
** SELECT c1 + 1, c1 FROM t1;
**
** Then this routine would return the string "VARIANT" for the second
** result column (i==1), and a NULL pointer for the first result column
** (i==0).
**
** SQLite uses dynamic run-time typing.  So just because a column
** is declared to contain a particular type does not mean that the
** data stored in that column is of the declared type.  SQLite is
** strongly typed, but the typing is dynamic not static.  Type
** is associated with individual values, not with the containers
** used to hold those values.
**
** INVARIANTS:
**
** {F13761}  A successful call to [sqlite3_column_decltype(S,N)]
**           returns a zero-terminated UTF-8 string containing the
**           the declared datatype of the table column that appears
**           as the Nth column (numbered from 0) of the result set to the
**           [prepared statement] S.
**
** {F13762}  A successful call to [sqlite3_column_decltype16(S,N)]
**           returns a zero-terminated UTF-16 native byte order string
**           containing the declared datatype of the table column that appears
**           as the Nth column (numbered from 0) of the result set to the
**           [prepared statement] S.
**
** {F13763}  If N is less than 0 or N is greater than or equal to
**           the number of columns in [prepared statement] S
**           or if the Nth column of S is an expression or subquery rather
**           than a table column or if a memory allocation failure
**           occurs during encoding conversions, then
**           calls to [sqlite3_column_decltype(S,N)] or
**           [sqlite3_column_decltype16(S,N)] return NULL.
*/
SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

/* 
** CAPI3REF:  Evaluate An SQL Statement {F13200}
**
** After an [prepared statement] has been prepared with a call
** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
** then this function must be called one or more times to evaluate the 
** statement.
**
** The details of the behavior of this sqlite3_step() interface depend
** on whether the statement was prepared using the newer "v2" interface
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
** new "v2" interface is recommended for new applications but the legacy
** interface will continue to be supported.
**
** In the legacy interface, the return value will be either [SQLITE_BUSY], 
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
** With the "v2" interface, any of the other [SQLITE_OK | result code]
** or [SQLITE_IOERR_READ | extended result code] might be returned as
** well.
**
** [SQLITE_BUSY] means that the database engine was unable to acquire the
** database locks it needs to do its job.  If the statement is a COMMIT
** or occurs outside of an explicit transaction, then you can retry the
** statement.  If the statement is not a COMMIT and occurs within a
** explicit transaction then you should rollback the transaction before
** continuing.
**
** [SQLITE_DONE] means that the statement has finished executing
** successfully.  sqlite3_step() should not be called again on this virtual
** machine without first calling [sqlite3_reset()] to reset the virtual
** machine back to its initial state.
**
** If the SQL statement being executed returns any data, then 
** [SQLITE_ROW] is returned each time a new row of data is ready
** for processing by the caller. The values may be accessed using
** the [sqlite3_column_int | column access functions].
** sqlite3_step() is called again to retrieve the next row of data.
** 
** [SQLITE_ERROR] means that a run-time error (such as a constraint
** violation) has occurred.  sqlite3_step() should not be called again on
** the VM. More information may be found by calling [sqlite3_errmsg()].
** With the legacy interface, a more specific error code (example:
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
** can be obtained by calling [sqlite3_reset()] on the
** [prepared statement].  In the "v2" interface,
** the more specific error code is returned directly by sqlite3_step().
**
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
** Perhaps it was called on a [prepared statement] that has
** already been [sqlite3_finalize | finalized] or on one that had 
** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
** be the case that the same database connection is being used by two or
** more threads at the same moment in time.
**
** <b>Goofy Interface Alert:</b>
** In the legacy interface, 
** the sqlite3_step() API always returns a generic error code,
** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
** and [SQLITE_MISUSE].  You must call [sqlite3_reset()] or
** [sqlite3_finalize()] in order to find one of the specific
** [error codes] that better describes the error.
** We admit that this is a goofy design.  The problem has been fixed
** with the "v2" interface.  If you prepare all of your SQL statements
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the 
** more specific [error codes] are returned directly
** by sqlite3_step().  The use of the "v2" interface is recommended.
**
** INVARIANTS:
**
** {F13202}  If [prepared statement] S is ready to be
**           run, then [sqlite3_step(S)] advances that prepared statement
**           until to completion or until it is ready to return another
**           row of the result set or an interrupt or run-time error occurs.
**
** {F15304}  When a call to [sqlite3_step(S)] causes the 
**           [prepared statement] S to run to completion,
**           the function returns [SQLITE_DONE].
**
** {F15306}  When a call to [sqlite3_step(S)] stops because it is ready
**           to return another row of the result set, it returns
**           [SQLITE_ROW].
**
** {F15308}  If a call to [sqlite3_step(S)] encounters an
**           [sqlite3_interrupt|interrupt] or a run-time error,
**           it returns an appropraite error code that is not one of
**           [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE].
**
** {F15310}  If an [sqlite3_interrupt|interrupt] or run-time error
**           occurs during a call to [sqlite3_step(S)]
**           for a [prepared statement] S created using
**           legacy interfaces [sqlite3_prepare()] or
**           [sqlite3_prepare16()] then the function returns either
**           [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE].
*/
SQLITE_API int sqlite3_step(sqlite3_stmt*);

/*
** CAPI3REF: Number of columns in a result set {F13770}
**
** Return the number of values in the current row of the result set.
**
** INVARIANTS:
**
** {F13771}  After a call to [sqlite3_step(S)] that returns
**           [SQLITE_ROW], the [sqlite3_data_count(S)] routine
**           will return the same value as the
**           [sqlite3_column_count(S)] function.
**
** {F13772}  After [sqlite3_step(S)] has returned any value other than
**           [SQLITE_ROW] or before [sqlite3_step(S)] has been 
**           called on the [prepared statement] for
**           the first time since it was [sqlite3_prepare|prepared]
**           or [sqlite3_reset|reset], the [sqlite3_data_count(S)]
**           routine returns zero.
*/
SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Fundamental Datatypes {F10265}
** KEYWORDS: SQLITE_TEXT
**
** {F10266}Every value in SQLite has one of five fundamental datatypes:
**
** <ul>
** <li> 64-bit signed integer
** <li> 64-bit IEEE floating point number
** <li> string
** <li> BLOB
** <li> NULL
** </ul> {END}
**
** These constants are codes for each of those types.
**
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
** for a completely different meaning.  Software that links against both
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
** SQLITE_TEXT.
*/
#define SQLITE_INTEGER  1
#define SQLITE_FLOAT    2
#define SQLITE_BLOB     4
#define SQLITE_NULL     5
#ifdef SQLITE_TEXT
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3

/*
** CAPI3REF: Results Values From A Query {F13800}
**
** These routines form the "result set query" interface.
**
** These routines return information about
** a single column of the current result row of a query.  In every
** case the first argument is a pointer to the 
** [prepared statement] that is being
** evaluated (the [sqlite3_stmt*] that was returned from 
** [sqlite3_prepare_v2()] or one of its variants) and
** the second argument is the index of the column for which information 
** should be returned.  The left-most column of the result set
** has an index of 0.
**
** If the SQL statement is not currently point to a valid row, or if the
** the column index is out of range, the result is undefined. 
** These routines may only be called when the most recent call to
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently.
** If any of these routines are called after [sqlite3_reset()] or
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
** something other than [SQLITE_ROW], the results are undefined.
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
** are called from a different thread while any of these routines
** are pending, then the results are undefined.  
**
** The sqlite3_column_type() routine returns 
** [SQLITE_INTEGER | datatype code] for the initial data type
** of the result column.  The returned value is one of [SQLITE_INTEGER],
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
** returned by sqlite3_column_type() is only meaningful if no type
** conversions have occurred as described below.  After a type conversion,
** the value returned by sqlite3_column_type() is undefined.  Future
** versions of SQLite may change the behavior of sqlite3_column_type()
** following a type conversion.
**
** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 
** routine returns the number of bytes in that BLOB or string.
** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
** the string to UTF-8 and then returns the number of bytes.
** If the result is a numeric value then sqlite3_column_bytes() uses
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
** the number of bytes in that string.
** The value returned does not include the zero terminator at the end
** of the string.  For clarity: the value returned is the number of
** bytes in the string, not the number of characters.
**
** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
** even empty strings, are always zero terminated.  The return
** value from sqlite3_column_blob() for a zero-length blob is an arbitrary
** pointer, possibly even a NULL pointer.
**
** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
** but leaves the result in UTF-16 in native byte order instead of UTF-8.  
** The zero terminator is not included in this count.
**
** The object returned by [sqlite3_column_value()] is an
** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
** If the [unprotected sqlite3_value] object returned by
** [sqlite3_column_value()] is used in any other way, including calls
** to routines like 
** [sqlite3_value_int()], [sqlite3_value_text()], or [sqlite3_value_bytes()],
** then the behavior is undefined.
**
** These routines attempt to convert the value where appropriate.  For
** example, if the internal representation is FLOAT and a text result
** is requested, [sqlite3_snprintf()] is used internally to do the conversion
** automatically.  The following table details the conversions that
** are applied:
**
** <blockquote>
** <table border="1">
** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
**
** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
** <tr><td> INTEGER  <td>   BLOB    <td> Same as for INTEGER->TEXT
** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
** <tr><td>  TEXT    <td>   BLOB    <td> No change
** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
** </table>
** </blockquote>
**
** The table above makes reference to standard C library functions atoi()
** and atof().  SQLite does not really use these functions.  It has its
** on equavalent internal routines.  The atoi() and atof() names are
** used in the table for brevity and because they are familiar to most
** C programmers.
**
** Note that when type conversions occur, pointers returned by prior
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
** sqlite3_column_text16() may be invalidated. 
** Type conversions and pointer invalidations might occur
** in the following cases:
**
** <ul>
** <li><p>  The initial content is a BLOB and sqlite3_column_text() 
**          or sqlite3_column_text16() is called.  A zero-terminator might
**          need to be added to the string.</p></li>
**
** <li><p>  The initial content is UTF-8 text and sqlite3_column_bytes16() or
**          sqlite3_column_text16() is called.  The content must be converted
**          to UTF-16.</p></li>
**
** <li><p>  The initial content is UTF-16 text and sqlite3_column_bytes() or
**          sqlite3_column_text() is called.  The content must be converted
**          to UTF-8.</p></li>
** </ul>
**
** Conversions between UTF-16be and UTF-16le are always done in place and do
** not invalidate a prior pointer, though of course the content of the buffer
** that the prior pointer points to will have been modified.  Other kinds
** of conversion are done in place when it is possible, but sometime it is
** not possible and in those cases prior pointers are invalidated.  
**
** The safest and easiest to remember policy is to invoke these routines
** in one of the following ways:
**
**  <ul>
**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
**  </ul>
**
** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
** or sqlite3_column_text16() first to force the result into the desired
** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
** find the size of the result.  Do not mix call to sqlite3_column_text() or
** sqlite3_column_blob() with calls to sqlite3_column_bytes16().  And do not
** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
**
** The pointers returned are valid until a type conversion occurs as
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
** [sqlite3_finalize()] is called.  The memory space used to hold strings
** and blobs is freed automatically.  Do <b>not</b> pass the pointers returned
** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 
** [sqlite3_free()].
**
** If a memory allocation error occurs during the evaluation of any
** of these routines, a default value is returned.  The default value
** is either the integer 0, the floating point number 0.0, or a NULL
** pointer.  Subsequent calls to [sqlite3_errcode()] will return
** [SQLITE_NOMEM].
**
** INVARIANTS:
**
** {F13803} The [sqlite3_column_blob(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a blob and then returns a
**          pointer to the converted value.
**
** {F13806} The [sqlite3_column_bytes(S,N)] interface returns the
**          number of bytes in the blob or string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_column_blob(S,N)] or
**          [sqlite3_column_text(S,N)].
**
** {F13809} The [sqlite3_column_bytes16(S,N)] interface returns the
**          number of bytes in the string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_column_text16(S,N)].
**
** {F13812} The [sqlite3_column_double(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a floating point value and
**          returns a copy of that value.
**
** {F13815} The [sqlite3_column_int(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a 64-bit signed integer and
**          returns the lower 32 bits of that integer.
**
** {F13818} The [sqlite3_column_int64(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a 64-bit signed integer and
**          returns a copy of that integer.
**
** {F13821} The [sqlite3_column_text(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a zero-terminated UTF-8 
**          string and returns a pointer to that string.
**
** {F13824} The [sqlite3_column_text16(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a zero-terminated 2-byte
**          aligned UTF-16 native byte order
**          string and returns a pointer to that string.
**
** {F13827} The [sqlite3_column_type(S,N)] interface returns
**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
**          the Nth column in the current row of the result set for
**          [prepared statement] S.
**
** {F13830} The [sqlite3_column_value(S,N)] interface returns a
**          pointer to an [unprotected sqlite3_value] object for the
**          Nth column in the current row of the result set for
**          [prepared statement] S.
*/
SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

/*
** CAPI3REF: Destroy A Prepared Statement Object {F13300}
**
** The sqlite3_finalize() function is called to delete a 
** [prepared statement]. If the statement was
** executed successfully, or not executed at all, then SQLITE_OK is returned.
** If execution of the statement failed then an 
** [error code] or [extended error code]
** is returned. 
**
** This routine can be called at any point during the execution of the
** [prepared statement].  If the virtual machine has not 
** completed execution when this routine is called, that is like
** encountering an error or an interrupt.  (See [sqlite3_interrupt()].) 
** Incomplete updates may be rolled back and transactions cancelled,  
** depending on the circumstances, and the 
** [error code] returned will be [SQLITE_ABORT].
**
** INVARIANTS:
**
** {F11302} The [sqlite3_finalize(S)] interface destroys the
**          [prepared statement] S and releases all
**          memory and file resources held by that object.
**
** {F11304} If the most recent call to [sqlite3_step(S)] for the
**          [prepared statement] S returned an error,
**          then [sqlite3_finalize(S)] returns that same error.
*/
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Reset A Prepared Statement Object {F13330}
**
** The sqlite3_reset() function is called to reset a 
** [prepared statement] object.
** back to its initial state, ready to be re-executed.
** Any SQL statement variables that had values bound to them using
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
** Use [sqlite3_clear_bindings()] to reset the bindings.
**
** {F11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S
**          back to the beginning of its program.
**
** {F11334} If the most recent call to [sqlite3_step(S)] for 
**          [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
**          or if [sqlite3_step(S)] has never before been called on S,
**          then [sqlite3_reset(S)] returns [SQLITE_OK].
**
** {F11336} If the most recent call to [sqlite3_step(S)] for
**          [prepared statement] S indicated an error, then
**          [sqlite3_reset(S)] returns an appropriate [error code].
**
** {F11338} The [sqlite3_reset(S)] interface does not change the values
**          of any [sqlite3_bind_blob|bindings] on [prepared statement] S.
*/
SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Create Or Redefine SQL Functions {F16100}
** KEYWORDS: {function creation routines} 
**
** These two functions (collectively known as
** "function creation routines") are used to add SQL functions or aggregates
** or to redefine the behavior of existing SQL functions or aggregates.  The
** difference only between the two is that the second parameter, the
** name of the (scalar) function or aggregate, is encoded in UTF-8 for
** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
**
** The first parameter is the [database connection] to which the SQL
** function is to be added.  If a single
** program uses more than one [database connection] internally, then SQL
** functions must be added individually to each [database connection].
**
** The second parameter is the name of the SQL function to be created
** or redefined.
** The length of the name is limited to 255 bytes, exclusive of the 
** zero-terminator.  Note that the name length limit is in bytes, not
** characters.  Any attempt to create a function with a longer name
** will result in an SQLITE_ERROR error.
**
** The third parameter is the number of arguments that the SQL function or
** aggregate takes. If this parameter is negative, then the SQL function or
** aggregate may take any number of arguments.
**
** The fourth parameter, eTextRep, specifies what 
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
** its parameters.  Any SQL function implementation should be able to work
** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
** more efficient with one encoding than another.  It is allowed to
** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
** times with the same function but with different values of eTextRep.
** When multiple implementations of the same function are available, SQLite
** will pick the one that involves the least amount of data conversion.
** If there is only a single implementation which does not care what
** text encoding is used, then the fourth argument should be
** [SQLITE_ANY].
**
** The fifth parameter is an arbitrary pointer.  The implementation
** of the function can gain access to this pointer using
** [sqlite3_user_data()].
**
** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL
** function or aggregate. A scalar SQL function requires an implementation of
** the xFunc callback only, NULL pointers should be passed as the xStep
** and xFinal parameters. An aggregate SQL function requires an implementation
** of xStep and xFinal and NULL should be passed for xFunc. To delete an
** existing SQL function or aggregate, pass NULL for all three function
** callback.
**
** It is permitted to register multiple implementations of the same
** functions with the same name but with either differing numbers of
** arguments or differing perferred text encodings.  SQLite will use
** the implementation most closely matches the way in which the
** SQL function is used.
**
** INVARIANTS:
**
** {F16103} The [sqlite3_create_function16()] interface behaves exactly
**          like [sqlite3_create_function()] in every way except that it
**          interprets the zFunctionName argument as
**          zero-terminated UTF-16 native byte order instead of as a
**          zero-terminated UTF-8.
**
** {F16106} A successful invocation of
**          the [sqlite3_create_function(D,X,N,E,...)] interface registers
**          or replaces callback functions in [database connection] D
**          used to implement the SQL function named X with N parameters
**          and having a perferred text encoding of E.
**
** {F16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          replaces the P, F, S, and L values from any prior calls with
**          the same D, X, N, and E values.
**
** {F16112} The [sqlite3_create_function(D,X,...)] interface fails with
**          a return code of [SQLITE_ERROR] if the SQL function name X is
**          longer than 255 bytes exclusive of the zero terminator.
**
** {F16118} Either F must be NULL and S and L are non-NULL or else F
**          is non-NULL and S and L are NULL, otherwise
**          [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR].
**
** {F16121} The [sqlite3_create_function(D,...)] interface fails with an
**          error code of [SQLITE_BUSY] if there exist [prepared statements]
**          associated with the [database connection] D.
**
** {F16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an
**          error code of [SQLITE_ERROR] if parameter N (specifying the number
**          of arguments to the SQL function being registered) is less
**          than -1 or greater than 127.
**
** {F16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)]
**          interface causes callbacks to be invoked for the SQL function
**          named X when the number of arguments to the SQL function is
**          exactly N.
**
** {F16130} When N is -1, the [sqlite3_create_function(D,X,N,...)]
**          interface causes callbacks to be invoked for the SQL function
**          named X with any number of arguments.
**
** {F16133} When calls to [sqlite3_create_function(D,X,N,...)]
**          specify multiple implementations of the same function X
**          and when one implementation has N>=0 and the other has N=(-1)
**          the implementation with a non-zero N is preferred.
**
** {F16136} When calls to [sqlite3_create_function(D,X,N,E,...)]
**          specify multiple implementations of the same function X with
**          the same number of arguments N but with different
**          encodings E, then the implementation where E matches the
**          database encoding is preferred.
**
** {F16139} For an aggregate SQL function created using
**          [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finializer
**          function L will always be invoked exactly once if the
**          step function S is called one or more times.
**
** {F16142} When SQLite invokes either the xFunc or xStep function of
**          an application-defined SQL function or aggregate created
**          by [sqlite3_create_function()] or [sqlite3_create_function16()],
**          then the array of [sqlite3_value] objects passed as the
**          third parameter are always [protected sqlite3_value] objects.
*/
SQLITE_API int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);
SQLITE_API int sqlite3_create_function16(
  sqlite3 *db,
  const void *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);

/*
** CAPI3REF: Text Encodings {F10267}
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* sqlite3_create_function only */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

/*
** CAPI3REF: Obsolete Functions
**
** These functions are all now obsolete.  In order to maintain
** backwards compatibility with older code, we continue to support
** these functions.  However, new development projects should avoid
** the use of these functions.  To help encourage people to avoid
** using these functions, we are not going to tell you want they do.
*/
SQLITE_API int sqlite3_aggregate_count(sqlite3_context*);
SQLITE_API int sqlite3_expired(sqlite3_stmt*);
SQLITE_API int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
SQLITE_API int sqlite3_global_recover(void);
SQLITE_API void sqlite3_thread_cleanup(void);
SQLITE_API int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);

/*
** CAPI3REF: Obtaining SQL Function Parameter Values {F15100}
**
** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
** define callbacks that implement the SQL functions and aggregates.
** The 4th parameter to these callbacks is an array of pointers to
** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
** each parameter to the SQL function.  These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** These routines work just like the corresponding 
** [sqlite3_column_blob | sqlite3_column_* routines] except that 
** these routines take a single [protected sqlite3_value] object pointer
** instead of an [sqlite3_stmt*] pointer and an integer column number.
**
** The sqlite3_value_text16() interface extracts a UTF16 string
** in the native byte-order of the host machine.  The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF16 strings as big-endian and little-endian respectively.
**
** The sqlite3_value_numeric_type() interface attempts to apply
** numeric affinity to the value.  This means that an attempt is
** made to convert the value to an integer or floating point.  If
** such a conversion is possible without loss of information (in other
** words if the value is a string that looks like a number)
** then the conversion is done.  Otherwise no conversion occurs.  The 
** [SQLITE_INTEGER | datatype] after conversion is returned.
**
** Please pay particular attention to the fact that the pointer that
** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].  
**
** These routines must be called from the same thread as
** the SQL function that supplied the [sqlite3_value*] parameters.
**
**
** INVARIANTS:
**
** {F15103} The [sqlite3_value_blob(V)] interface converts the
**          [protected sqlite3_value] object V into a blob and then returns a
**          pointer to the converted value.
**
** {F15106} The [sqlite3_value_bytes(V)] interface returns the
**          number of bytes in the blob or string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_value_blob(V)] or
**          [sqlite3_value_text(V)].
**
** {F15109} The [sqlite3_value_bytes16(V)] interface returns the
**          number of bytes in the string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_value_text16(V)],
**          [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)].
**
** {F15112} The [sqlite3_value_double(V)] interface converts the
**          [protected sqlite3_value] object V into a floating point value and
**          returns a copy of that value.
**
** {F15115} The [sqlite3_value_int(V)] interface converts the
**          [protected sqlite3_value] object V into a 64-bit signed integer and
**          returns the lower 32 bits of that integer.
**
** {F15118} The [sqlite3_value_int64(V)] interface converts the
**          [protected sqlite3_value] object V into a 64-bit signed integer and
**          returns a copy of that integer.
**
** {F15121} The [sqlite3_value_text(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated UTF-8 
**          string and returns a pointer to that string.
**
** {F15124} The [sqlite3_value_text16(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 native byte order
**          string and returns a pointer to that string.
**
** {F15127} The [sqlite3_value_text16be(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 big-endian
**          string and returns a pointer to that string.
**
** {F15130} The [sqlite3_value_text16le(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 little-endian
**          string and returns a pointer to that string.
**
** {F15133} The [sqlite3_value_type(V)] interface returns
**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
**          the [sqlite3_value] object V.
**
** {F15136} The [sqlite3_value_numeric_type(V)] interface converts
**          the [protected sqlite3_value] object V into either an integer or
**          a floating point value if it can do so without loss of
**          information, and returns one of [SQLITE_NULL],
**          [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or
**          [SQLITE_BLOB] as appropriate for
**          the [protected sqlite3_value] object V after the conversion attempt.
*/
SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
SQLITE_API double sqlite3_value_double(sqlite3_value*);
SQLITE_API int sqlite3_value_int(sqlite3_value*);
SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
SQLITE_API int sqlite3_value_type(sqlite3_value*);
SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context {F16210}
**
** The implementation of aggregate SQL functions use this routine to allocate
** a structure for storing their state.  
** The first time the sqlite3_aggregate_context() routine is
** is called for a particular aggregate, SQLite allocates nBytes of memory
** zeros that memory, and returns a pointer to it.
** On second and subsequent calls to sqlite3_aggregate_context()
** for the same aggregate function index, the same buffer is returned.
** The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** SQLite automatically frees the allocated buffer when the aggregate
** query concludes.
**
** The first parameter should be a copy of the 
** [sqlite3_context | SQL function context] that is the first
** parameter to the callback routine that implements the aggregate
** function.
**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.
**
** INVARIANTS:
**
** {F16211} The first invocation of [sqlite3_aggregate_context(C,N)] for
**          a particular instance of an aggregate function (for a particular
**          context C) causes SQLite to allocation N bytes of memory,
**          zero that memory, and return a pointer to the allocationed
**          memory.
**
** {F16213} If a memory allocation error occurs during
**          [sqlite3_aggregate_context(C,N)] then the function returns 0.
**
** {F16215} Second and subsequent invocations of
**          [sqlite3_aggregate_context(C,N)] for the same context pointer C
**          ignore the N parameter and return a pointer to the same
**          block of memory returned by the first invocation.
**
** {F16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is
**          automatically freed on the next call to [sqlite3_reset()]
**          or [sqlite3_finalize()] for the [prepared statement] containing
**          the aggregate function associated with context C.
*/
SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** CAPI3REF: User Data For Functions {F16240}
**
** The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function. {END}
**
** This routine must be called from the same thread in which
** the application-defined function is running.
**
** INVARIANTS:
**
** {F16243} The [sqlite3_user_data(C)] interface returns a copy of the
**          P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
**          registered the SQL function associated with 
**          [sqlite3_context] C.
*/
SQLITE_API void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Database Connection For Functions {F16250}
**
** The sqlite3_context_db_handle() interface returns a copy of
** the pointer to the [database connection] (the 1st parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.
**
** INVARIANTS:
**
** {F16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the
**          D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
**          registered the SQL function associated with 
**          [sqlite3_context] C.
*/
SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data {F16270}
**
** The following two functions may be used by scalar SQL functions to
** associate meta-data with argument values. If the same value is passed to
** multiple invocations of the same SQL function during query execution, under
** some circumstances the associated meta-data may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** meta-data associated with the SQL value passed as the regular expression
** pattern.  The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**
** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function.
** If no meta-data has been ever been set for the Nth
** argument of the function, or if the cooresponding function parameter
** has changed since the meta-data was set, then sqlite3_get_auxdata()
** returns a NULL pointer.
**
** The sqlite3_set_auxdata() interface saves the meta-data
** pointed to by its 3rd parameter as the meta-data for the N-th
** argument of the application-defined function.  Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed. 
** If it is not NULL, SQLite will invoke the destructor 
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the meta-data when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first.
**
** SQLite is free to call the destructor and drop meta-data on
** any parameter of any function at any time.  The only guarantee
** is that the destructor will be called before the metadata is
** dropped.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
**
** INVARIANTS:
**
** {F16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer
**          to metadata associated with the Nth parameter of the SQL function
**          whose context is C, or NULL if there is no metadata associated
**          with that parameter.
**
** {F16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata
**          pointer P to the Nth parameter of the SQL function with context
**          C.
**
** {F16276} SQLite will invoke the destructor D with a single argument
**          which is the metadata pointer P following a call to
**          [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold
**          the metadata.
**
** {F16277} SQLite ceases to hold metadata for an SQL function parameter
**          when the value of that parameter changes.
**
** {F16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor
**          is called for any prior metadata associated with the same function
**          context C and parameter N.
**
** {F16279} SQLite will call destructors for any metadata it is holding
**          in a particular [prepared statement] S when either
**          [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called.
*/
SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior {F10280}
**
** These are special value for the destructor that is passed in as the
** final argument to routines like [sqlite3_result_blob()].  If the destructor
** argument is SQLITE_STATIC, it means that the content pointer is constant
** and will never change.  It does not need to be destroyed.  The 
** SQLITE_TRANSIENT value means that the content will likely change in
** the near future and that SQLite should make its own private copy of
** the content before returning.
**
** The typedef is necessary to work around problems in certain
** C++ compilers.  See ticket #2191.
*/
typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

/*
** CAPI3REF: Setting The Result Of An SQL Function {F16400}
**
** These routines are used by the xFunc or xFinal callbacks that
** implement SQL functions and aggregates.  See
** [sqlite3_create_function()] and [sqlite3_create_function16()]
** for additional information.
**
** These functions work very much like the 
** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
** to bind values to host parameters in prepared statements.
** Refer to the
** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
** additional information.
**
** The sqlite3_result_blob() interface sets the result from
** an application defined function to be the BLOB whose content is pointed
** to by the second parameter and which is N bytes long where N is the
** third parameter. 
** The sqlite3_result_zeroblob() inerfaces set the result of
** the application defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** The sqlite3_result_double() interface sets the result from
** an application defined function to be a floating point value specified
** by its 2nd argument.
**
** The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** SQLite uses the string pointed to by the
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
** as the text of an error message.  SQLite interprets the error
** message string from sqlite3_result_error() as UTF8. SQLite
** interprets the string from sqlite3_result_error16() as UTF16 in native
** byte order.  If the third parameter to sqlite3_result_error()
** or sqlite3_result_error16() is negative then SQLite takes as the error
** message all text up through the first zero character.
** If the third parameter to sqlite3_result_error() or
** sqlite3_result_error16() is non-negative then SQLite takes that many
** bytes (not characters) from the 2nd parameter as the error message.
** The sqlite3_result_error() and sqlite3_result_error16()
** routines make a copy private copy of the error message text before
** they return.  Hence, the calling function can deallocate or
** modify the text after they return without harm.
** The sqlite3_result_error_code() function changes the error code
** returned by SQLite as a result of an error in a function.  By default,
** the error code is SQLITE_ERROR.  A subsequent call to sqlite3_result_error()
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
**
** The sqlite3_result_toobig() interface causes SQLite
** to throw an error indicating that a string or BLOB is to long
** to represent.  The sqlite3_result_nomem() interface
** causes SQLite to throw an exception indicating that the a
** memory allocation failed.
**
** The sqlite3_result_int() interface sets the return value
** of the application-defined function to be the 32-bit signed integer
** value given in the 2nd argument.
** The sqlite3_result_int64() interface sets the return value
** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** The sqlite3_result_text(), sqlite3_result_text16(), 
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter 
** through the first zero character.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text
** pointed to by the 2nd parameter are taken as the application-defined
** function result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
** function as the destructor on the text or blob result when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_STATIC, then
** SQLite assumes that the text or blob result is constant space and
** does not copy the space or call a destructor when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the
** [unprotected sqlite3_value] object specified by the 2nd parameter.  The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread 
** than the one containing the application-defined function that recieved
** the [sqlite3_context] pointer, the results are undefined.
**
** INVARIANTS:
**
** {F16403} The default return value from any SQL function is NULL.
**
** {F16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the
**          return value of function C to be a blob that is N bytes
**          in length and with content pointed to by V.
**
** {F16409} The [sqlite3_result_double(C,V)] interface changes the
**          return value of function C to be the floating point value V.
**
** {F16412} The [sqlite3_result_error(C,V,N)] interface changes the return
**          value of function C to be an exception with error code
**          [SQLITE_ERROR] and a UTF8 error message copied from V up to the
**          first zero byte or until N bytes are read if N is positive.
**
** {F16415} The [sqlite3_result_error16(C,V,N)] interface changes the return
**          value of function C to be an exception with error code
**          [SQLITE_ERROR] and a UTF16 native byte order error message
**          copied from V up to the first zero terminator or until N bytes
**          are read if N is positive.
**
** {F16418} The [sqlite3_result_error_toobig(C)] interface changes the return
**          value of the function C to be an exception with error code
**          [SQLITE_TOOBIG] and an appropriate error message.
**
** {F16421} The [sqlite3_result_error_nomem(C)] interface changes the return
**          value of the function C to be an exception with error code
**          [SQLITE_NOMEM] and an appropriate error message.
**
** {F16424} The [sqlite3_result_error_code(C,E)] interface changes the return
**          value of the function C to be an exception with error code E.
**          The error message text is unchanged.
**
** {F16427} The [sqlite3_result_int(C,V)] interface changes the
**          return value of function C to be the 32-bit integer value V.
**
** {F16430} The [sqlite3_result_int64(C,V)] interface changes the
**          return value of function C to be the 64-bit integer value V.
**
** {F16433} The [sqlite3_result_null(C)] interface changes the
**          return value of function C to be NULL.
**
** {F16436} The [sqlite3_result_text(C,V,N,D)] interface changes the
**          return value of function C to be the UTF8 string
**          V up to the first zero if N is negative
**          or the first N bytes of V if N is non-negative.
**
** {F16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 native byte order
**          string V up to the first zero if N is
**          negative or the first N bytes of V if N is non-negative.
**
** {F16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 big-endian
**          string V up to the first zero if N is
**          is negative or the first N bytes or V if N is non-negative.
**
** {F16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 little-endian
**          string V up to the first zero if N is
**          negative or the first N bytes of V if N is non-negative.
**
** {F16448} The [sqlite3_result_value(C,V)] interface changes the
**          return value of function C to be [unprotected sqlite3_value]
**          object V.
**
** {F16451} The [sqlite3_result_zeroblob(C,N)] interface changes the
**          return value of function C to be an N-byte blob of all zeros.
**
** {F16454} The [sqlite3_result_error()] and [sqlite3_result_error16()]
**          interfaces make a copy of their error message strings before
**          returning.
**
** {F16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC]
**          then no destructor is ever called on the pointer V and SQLite
**          assumes that V is immutable.
**
** {F16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is the constant
**          [SQLITE_TRANSIENT] then the interfaces makes a copy of the
**          content of V and retains the copy.
**
** {F16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is some value other than
**          the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then 
**          SQLite will invoke the destructor D with V as its only argument
**          when it has finished with the V value.
*/
SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
SQLITE_API void sqlite3_result_null(sqlite3_context*);
SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*
** CAPI3REF: Define New Collating Sequences {F16600}
**
** These functions are used to add new collation sequences to the
** [sqlite3*] handle specified as the first argument. 
**
** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). In all cases
** the name is passed as the second function argument.
**
** The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian or UTF-16 big-endian respectively. The
** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that
** the routine expects pointers to 16-bit word aligned strings
** of UTF16 in the native byte order of the host computer.
**
** A pointer to the user supplied routine must be passed as the fifth
** argument.  If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** Each time the application
** supplied function is invoked, it is passed a copy of the void* passed as
** the fourth argument to sqlite3_create_collation() or
** sqlite3_create_collation16() as its first parameter.
**
** The remaining arguments to the application-supplied routine are two strings,
** each represented by a (length, data) pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered. {END} The application defined collation routine should
** return negative, zero or positive if
** the first string is less than, equal to, or greater than the second
** string. i.e. (STRING1 - STRING2).
**
** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** excapt that it takes an extra argument which is a destructor for
** the collation.  The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** Collations are destroyed when
** they are overridden by later calls to the collation creation functions
** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
**
** INVARIANTS:
**
** {F16603} A successful call to the
**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface
**          registers function F as the comparison function used to
**          implement collation X on [database connection] B for
**          databases having encoding E.
**
** {F16604} SQLite understands the X parameter to
**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated
**          UTF-8 string in which case is ignored for ASCII characters and
**          is significant for non-ASCII characters.
**
** {F16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          with the same values for B, X, and E, override prior values
**          of P, F, and D.
**
** {F16609} The destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          is not NULL then it is called with argument P when the
**          collating function is dropped by SQLite.
**
** {F16612} A collating function is dropped when it is overloaded.
**
** {F16615} A collating function is dropped when the database connection
**          is closed using [sqlite3_close()].
**
** {F16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          is passed through as the first parameter to the comparison
**          function F for all subsequent invocations of F.
**
** {F16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly
**          the same as a call to [sqlite3_create_collation_v2()] with
**          the same parameters and a NULL destructor.
**
** {F16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)],
**          SQLite uses the comparison function F for all text comparison
**          operations on [database connection] B on text values that
**          use the collating sequence name X.
**
** {F16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same
**          as [sqlite3_create_collation(B,X,E,P,F)] except that the
**          collation name X is understood as UTF-16 in native byte order
**          instead of UTF-8.
**
** {F16630} When multiple comparison functions are available for the same
**          collating sequence, SQLite chooses the one whose text encoding
**          requires the least amount of conversion from the default
**          text encoding of the database.
*/
SQLITE_API int sqlite3_create_collation(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);
SQLITE_API int sqlite3_create_collation_v2(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*),
  void(*xDestroy)(void*)
);
SQLITE_API int sqlite3_create_collation16(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);

/*
** CAPI3REF: Collation Needed Callbacks {F16700}
**
** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** database handle to be called whenever an undefined collation sequence is
** required.
**
** If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names
** are passed as UTF-16 in machine native byte order. A call to either
** function replaces any existing callback.
**
** When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16().  The second argument is the database
** handle.  The third argument is one of [SQLITE_UTF8],
** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most
** desirable form of the collation sequence function required.
** The fourth parameter is the name of the
** required collation sequence.
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
**
** INVARIANTS:
**
** {F16702} A successful call to [sqlite3_collation_needed(D,P,F)]
**          or [sqlite3_collation_needed16(D,P,F)] causes
**          the [database connection] D to invoke callback F with first
**          parameter P whenever it needs a comparison function for a
**          collating sequence that it does not know about.
**
** {F16704} Each successful call to [sqlite3_collation_needed()] or
**          [sqlite3_collation_needed16()] overrides the callback registered
**          on the same [database connection] by prior calls to either
**          interface.
**
** {F16706} The name of the requested collating function passed in the
**          4th parameter to the callback is in UTF-8 if the callback
**          was registered using [sqlite3_collation_needed()] and
**          is in UTF-16 native byte order if the callback was
**          registered using [sqlite3_collation_needed16()].
**
** 
*/
SQLITE_API int sqlite3_collation_needed(
  sqlite3*, 
  void*, 
  void(*)(void*,sqlite3*,int eTextRep,const char*)
);
SQLITE_API int sqlite3_collation_needed16(
  sqlite3*, 
  void*,
  void(*)(void*,sqlite3*,int eTextRep,const void*)
);

/*
** Specify the key for an encrypted database.  This routine should be
** called right after sqlite3_open().
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
SQLITE_API int sqlite3_key(
  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The key */
);

/*
** Change the key on an open database.  If the current database is not
** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
** database is decrypted.
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
SQLITE_API int sqlite3_rekey(
  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF:  Suspend Execution For A Short Time {F10530}
**
** The sqlite3_sleep() function
** causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** If the operating system does not support sleep requests with 
** millisecond time resolution, then the time will be rounded up to 
** the nearest second. The number of milliseconds of sleep actually 
** requested from the operating system is returned.
**
** SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.
**
** INVARIANTS:
**
** {F10533} The [sqlite3_sleep(M)] interface invokes the xSleep
**          method of the default [sqlite3_vfs|VFS] in order to
**          suspend execution of the current thread for at least
**          M milliseconds.
**
** {F10536} The [sqlite3_sleep(M)] interface returns the number of
**          milliseconds of sleep actually requested of the operating
**          system, which might be larger than the parameter M.
*/
SQLITE_API int sqlite3_sleep(int);

/*
** CAPI3REF:  Name Of The Folder Holding Temporary Files {F10310}
**
** If this global variable is made to point to a string which is
** the name of a folder (a.ka. directory), then all temporary files
** created by SQLite will be placed in that directory.  If this variable
** is NULL pointer, then SQLite does a search for an appropriate temporary
** file directory.
**
** It is not safe to modify this variable once a database connection
** has been opened.  It is intended that this variable be set once
** as part of process initialization and before any SQLite interface
** routines have been call and remain unchanged thereafter.
*/
SQLITE_API char *sqlite3_temp_directory;

/*
** CAPI3REF:  Test To See If The Database Is In Auto-Commit Mode {F12930}
**
** The sqlite3_get_autocommit() interfaces returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively.   Autocommit mode is on
** by default.  Autocommit mode is disabled by a [BEGIN] statement.
** Autocommit mode is reenabled by a [COMMIT] or [ROLLBACK].
**
** If certain kinds of errors occur on a statement within a multi-statement
** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR], 
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  The only way to
** find out if SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** INVARIANTS:
**
** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or
**          zero if the [database connection] D is or is not in autocommit
**          mode, respectively.
**
** {F12932} Autocommit mode is on by default.
**
** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement.
**
** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]
**          statement.
** 
**
** LIMITATIONS:
***
** {U12936} If another thread changes the autocommit status of the database
**          connection while this routine is running, then the return value
**          is undefined.
*/
SQLITE_API int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF:  Find The Database Handle Of A Prepared Statement {F13120}
**
** The sqlite3_db_handle interface
** returns the [sqlite3*] database handle to which a
** [prepared statement] belongs.
** The database handle returned by sqlite3_db_handle
** is the same database handle that was
** the first argument to the [sqlite3_prepare_v2()] or its variants
** that was used to create the statement in the first place.
**
** INVARIANTS:
**
** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer
**          to the [database connection] associated with
**          [prepared statement] S.
*/
SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);


/*
** CAPI3REF: Commit And Rollback Notification Callbacks {F12950}
**
** The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The pArg argument is passed through
** to the callback.  If the callback on a commit hook function 
** returns non-zero, then the commit is converted into a rollback.
**
** If another function was previously registered, its
** pArg value is returned.  Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
** For the purposes of this API, a transaction is said to have been 
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo>
**
** These are experimental interfaces and are subject to change.
**
** INVARIANTS:
**
** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction commits on [database connection] D.
**
** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P
**          argument from the previous call with the same 
**          [database connection ] D , or NULL on the first call
**          for a particular [database connection] D.
**
** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL
**          then the commit hook callback is cancelled and no callback
**          is invoked when a transaction commits.
**
** {F12955} If the commit callback returns non-zero then the commit is
**          converted into a rollback.
**
** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction rolls back on [database connection] D.
**
** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P
**          argument from the previous call with the same 
**          [database connection ] D , or NULL on the first call
**          for a particular [database connection] D.
**
** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL
**          then the rollback hook callback is cancelled and no callback
**          is invoked when a transaction rolls back.
*/
SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks {F12970}
**
** The sqlite3_update_hook() interface
** registers a callback function with the database connection identified by the 
** first argument to be invoked whenever a row is updated, inserted or deleted.
** Any callback set by a previous call to this function for the same 
** database connection is overridden.
**
** The second argument is a pointer to the function to invoke when a 
** row is updated, inserted or deleted. 
** The first argument to the callback is
** a copy of the third argument to sqlite3_update_hook().
** The second callback 
** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
** depending on the operation that caused the callback to be invoked.
** The third and 
** fourth arguments to the callback contain pointers to the database and 
** table name containing the affected row.
** The final callback parameter is 
** the rowid of the row.
** In the case of an update, this is the rowid after 
** the update takes place.
**
** The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** If another function was previously registered, its pArg value
** is returned.  Otherwise NULL is returned.
**
** INVARIANTS:
**
** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes callback
**          function F to be invoked with first parameter P whenever
**          a table row is modified, inserted, or deleted on
**          [database connection] D.
**
** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value
**          of P for the previous call on the same [database connection] D,
**          or NULL for the first call.
**
** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]
**          is NULL then the no update callbacks are made.
**
** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls
**          to the same interface on the same [database connection] D.
**
** {F12979} The update hook callback is not invoked when internal system
**          tables such as sqlite_master and sqlite_sequence are modified.
**
** {F12981} The second parameter to the update callback 
**          is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
**          depending on the operation that caused the callback to be invoked.
**
** {F12983} The third and fourth arguments to the callback contain pointers
**          to zero-terminated UTF-8 strings which are the names of the
**          database and table that is being updated.

** {F12985} The final callback parameter is the rowid of the row after
**          the change occurs.
*/
SQLITE_API void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);

/*
** CAPI3REF:  Enable Or Disable Shared Pager Cache {F10330}
**
** This routine enables or disables the sharing of the database cache
** and schema data structures between connections to the same database.
** Sharing is enabled if the argument is true and disabled if the argument
** is false.
**
** Cache sharing is enabled and disabled
** for an entire process. {END} This is a change as of SQLite version 3.5.0.
** In prior versions of SQLite, sharing was
** enabled or disabled for each thread separately.
**
** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.
**
** Virtual tables cannot be used with a shared cache.   When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error.
**
** This routine returns [SQLITE_OK] if shared cache was
** enabled or disabled successfully.  An [error code]
** is returned otherwise.
**
** Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** INVARIANTS:
** 
** {F10331} A successful invocation of [sqlite3_enable_shared_cache(B)]
**          will enable or disable shared cache mode for any subsequently
**          created [database connection] in the same process.
**
** {F10336} When shared cache is enabled, the [sqlite3_create_module()]
**          interface will always return an error.
**
** {F10337} The [sqlite3_enable_shared_cache(B)] interface returns
**          [SQLITE_OK] if shared cache was enabled or disabled successfully.
**
** {F10339} Shared cache is disabled by default.
*/
SQLITE_API int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF:  Attempt To Free Heap Memory {F17340}
**
** The sqlite3_release_memory() interface attempts to
** free N bytes of heap memory by deallocating non-essential memory
** allocations held by the database labrary. {END}  Memory used
** to cache database pages to improve performance is an example of
** non-essential memory.  Sqlite3_release_memory() returns
** the number of bytes actually freed, which might be more or less
** than the amount requested.
**
** INVARIANTS:
**
** {F17341} The [sqlite3_release_memory(N)] interface attempts to
**          free N bytes of heap memory by deallocating non-essential
**          memory allocations held by the database labrary.
**
** {F16342} The [sqlite3_release_memory(N)] returns the number
**          of bytes actually freed, which might be more or less
**          than the amount requested.
*/
SQLITE_API int sqlite3_release_memory(int);

/*
** CAPI3REF:  Impose A Limit On Heap Size {F17350}
**
** The sqlite3_soft_heap_limit() interface
** places a "soft" limit on the amount of heap memory that may be allocated
** by SQLite. If an internal allocation is requested 
** that would exceed the soft heap limit, [sqlite3_release_memory()] is
** invoked one or more times to free up some space before the allocation
** is made.
**
** The limit is called "soft", because if
** [sqlite3_release_memory()] cannot
** free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  
** But if the soft heap limit cannot honored, execution will
** continue without error or notification.  This is why the limit is 
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.
**
** INVARIANTS:
**
** {F16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit
**          of N bytes on the amount of heap memory that may be allocated
**          using [sqlite3_malloc()] or [sqlite3_realloc()] at any point
**          in time.
**
** {F16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would
**          cause the total amount of allocated memory to exceed the
**          soft heap limit, then [sqlite3_release_memory()] is invoked
**          in an attempt to reduce the memory usage prior to proceeding
**          with the memory allocation attempt.
**
** {F16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger
**          attempts to reduce memory usage through the soft heap limit
**          mechanism continue even if the attempt to reduce memory
**          usage is unsuccessful.
**
** {F16354} A negative or zero value for N in a call to
**          [sqlite3_soft_heap_limit(N)] means that there is no soft
**          heap limit and [sqlite3_release_memory()] will only be
**          called when memory is completely exhausted.
**
** {F16355} The default value for the soft heap limit is zero.
**
** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the
**          values set by all prior calls.
*/
SQLITE_API void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF:  Extract Metadata About A Column Of A Table {F12850}
**
** This routine
** returns meta-data about a specific column of a specific database
** table accessible using the connection handle passed as the first function 
** argument.
**
** The column is identified by the second, third and fourth parameters to 
** this function. The second parameter is either the name of the database
** (i.e. "main", "temp" or an attached database) containing the specified
** table or NULL. If it is NULL, then all attached databases are searched
** for the table using the same algorithm as the database engine uses to 
** resolve unqualified table references.
**
** The third and fourth parameters to this function are the table and column 
** name of the desired column, respectively. Neither of these parameters 
** may be NULL.
**
** Meta information is returned by writing to the memory locations passed as
** the 5th and subsequent parameters to this function. Any of these 
** arguments may be NULL, in which case the corresponding element of meta 
** information is ommitted.
**
** <pre>
** Parameter     Output Type      Description
** -----------------------------------
**
**   5th         const char*      Data type
**   6th         const char*      Name of the default collation sequence 
**   7th         int              True if the column has a NOT NULL constraint
**   8th         int              True if the column is part of the PRIMARY KEY
**   9th         int              True if the column is AUTOINCREMENT
** </pre>
**
**
** The memory pointed to by the character pointers returned for the 
** declaration type and collation sequence is valid only until the next 
** call to any sqlite API function.
**
** If the specified table is actually a view, then an error is returned.
**
** If the specified column is "rowid", "oid" or "_rowid_" and an 
** INTEGER PRIMARY KEY column has been explicitly declared, then the output 
** parameters are set for the explicitly declared column. If there is no
** explicitly declared IPK column, then the output parameters are set as 
** follows:
**
** <pre>
**     data type: "INTEGER"
**     collation sequence: "BINARY"
**     not null: 0
**     primary key: 1
**     auto increment: 0
** </pre>
**
** This function may load one or more schemas from database files. If an
** error occurs during this process, or if the requested table or column
** cannot be found, an SQLITE error code is returned and an error message
** left in the database handle (to be retrieved using sqlite3_errmsg()).
**
** This API is only available if the library was compiled with the
** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
*/
SQLITE_API int sqlite3_table_column_metadata(
  sqlite3 *db,                /* Connection handle */
  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
  char const **pzDataType,    /* OUTPUT: Declared data type */
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension {F12600}
**
** {F12601} The sqlite3_load_extension() interface
** attempts to load an SQLite extension library contained in the file
** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0
** in which case the name of the entry point defaults
** to "sqlite3_extension_init".
**
** {F12604} The sqlite3_load_extension() interface shall
** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
**
** {F12605}
** If an error occurs and pzErrMsg is not 0, then the
** sqlite3_load_extension() interface shall attempt to fill *pzErrMsg with 
** error message text stored in memory obtained from [sqlite3_malloc()].
** {END}  The calling function should free this memory
** by calling [sqlite3_free()].
**
** {F12606}
** Extension loading must be enabled using [sqlite3_enable_load_extension()]
** prior to calling this API or an error will be returned.
*/
SQLITE_API int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
);

/*
** CAPI3REF:  Enable Or Disable Extension Loading {F12620}
**
** So as not to open security holes in older applications that are
** unprepared to deal with extension loading, and as a means of disabling
** extension loading while evaluating user-entered SQL, the following
** API is provided to turn the [sqlite3_load_extension()] mechanism on and
** off.  {F12622} It is off by default. {END} See ticket #1863.
**
** {F12621} Call the sqlite3_enable_load_extension() routine
** with onoff==1 to turn extension loading on
** and call it with onoff==0 to turn it back off again. {END}
*/
SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

/*
** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640}
**
** {F12641} This function
** registers an extension entry point that is automatically invoked
** whenever a new database connection is opened using
** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END}
**
** This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new database connections.
**
** {F12642} Duplicate extensions are detected so calling this routine multiple
** times with the same extension is harmless.
**
** {F12643} This routine stores a pointer to the extension in an array
** that is obtained from sqlite_malloc(). {END} If you run a memory leak
** checker on your program and it reports a leak because of this
** array, then invoke [sqlite3_reset_auto_extension()] prior
** to shutdown to free the memory.
**
** {F12644} Automatic extensions apply across all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
SQLITE_API int sqlite3_auto_extension(void *xEntryPoint);


/*
** CAPI3REF: Reset Automatic Extension Loading {F12660}
**
** {F12661} This function disables all previously registered
** automatic extensions. {END}  This
** routine undoes the effect of all prior [sqlite3_auto_extension()]
** calls.
**
** {F12662} This call disabled automatic extensions in all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
SQLITE_API void sqlite3_reset_auto_extension(void);


/*
****** EXPERIMENTAL - subject to change without notice **************
**
** The interface to the virtual-table mechanism is currently considered
** to be experimental.  The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.
**
** When the virtual-table mechanism stablizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
*/

/*
** Structures used by the virtual table interface
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;

/*
** CAPI3REF: Virtual Table Object {F18000}
** KEYWORDS: sqlite3_module
**
** A module is a class of virtual tables.  Each module is defined
** by an instance of the following structure.  This structure consists
** mostly of methods for the module.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,
               int argc, const char *const*argv,
               sqlite3_vtab **ppVTab, char**);
  int (*xConnect)(sqlite3*, void *pAux,
               int argc, const char *const*argv,
               sqlite3_vtab **ppVTab, char**);
  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
  int (*xDisconnect)(sqlite3_vtab *pVTab);
  int (*xDestroy)(sqlite3_vtab *pVTab);
  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
  int (*xClose)(sqlite3_vtab_cursor*);
  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
                int argc, sqlite3_value **argv);
  int (*xNext)(sqlite3_vtab_cursor*);
  int (*xEof)(sqlite3_vtab_cursor*);
  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
  int (*xBegin)(sqlite3_vtab *pVTab);
  int (*xSync)(sqlite3_vtab *pVTab);
  int (*xCommit)(sqlite3_vtab *pVTab);
  int (*xRollback)(sqlite3_vtab *pVTab);
  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);

  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*
** CAPI3REF: Virtual Table Indexing Information {F18100}
** KEYWORDS: sqlite3_index_info
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the xBestIndex
** method of an sqlite3_module.  The fields under **Inputs** are the
** inputs to xBestIndex and are read-only.  xBestIndex inserts its
** results into the **Outputs** fields.
**
** The aConstraint[] array records WHERE clause constraints of the
** form:
**
**         column OP expr
**
** Where OP is =, &lt;, &lt;=, &gt;, or &gt;=.  
** The particular operator is stored
** in aConstraint[].op.  The index of the column is stored in 
** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
** expr on the right-hand side can be evaluated (and thus the constraint
** is usable) and false if it cannot.
**
** The optimizer automatically inverts terms of the form "expr OP column"
** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** The aConstraint[] array only reports WHERE clause terms in the correct
** form that refer to the particular virtual table being queried.
**
** Information about the ORDER BY clause is stored in aOrderBy[].
** Each term of aOrderBy records a column of the ORDER BY clause.
**
** The xBestIndex method must fill aConstraintUsage[] with information
** about what parameters to pass to xFilter.  If argvIndex>0 then
** the right-hand side of the corresponding aConstraint[] is evaluated
** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
** is true, then the constraint is assumed to be fully handled by the
** virtual table and is not checked again by SQLite.
**
** The idxNum and idxPtr values are recorded and passed into xFilter.
** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
**
** The orderByConsumed means that output from xFilter will occur in
** the correct order to satisfy the ORDER BY clause so that no separate
** sorting step is required.
**
** The estimatedCost value is an estimate of the cost of doing the
** particular lookup.  A full scan of a table with N entries should have
** a cost of N.  A binary search of a table of N entries should have a
** cost of approximately log(N).
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
     unsigned char usable;     /* True if this constraint is usable */
     int iTermOffset;          /* Used internally - xBestIndex should ignore */
  } *aConstraint;            /* Table of WHERE clause constraints */
  int nOrderBy;              /* Number of terms in the ORDER BY clause */
  struct sqlite3_index_orderby {
     int iColumn;              /* Column number */
     unsigned char desc;       /* True for DESC.  False for ASC. */
  } *aOrderBy;               /* The ORDER BY clause */

  /* Outputs */
  struct sqlite3_index_constraint_usage {
    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
    unsigned char omit;      /* Do not code a test for this constraint */
  } *aConstraintUsage;
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;      /* Estimated cost of using this index */
};
#define SQLITE_INDEX_CONSTRAINT_EQ    2
#define SQLITE_INDEX_CONSTRAINT_GT    4
#define SQLITE_INDEX_CONSTRAINT_LE    8
#define SQLITE_INDEX_CONSTRAINT_LT    16
#define SQLITE_INDEX_CONSTRAINT_GE    32
#define SQLITE_INDEX_CONSTRAINT_MATCH 64

/*
** CAPI3REF: Register A Virtual Table Implementation {F18200}
**
** This routine is used to register a new module name with an SQLite
** connection.  Module names must be registered before creating new
** virtual tables on the module, or before using preexisting virtual
** tables of the module.
*/
SQLITE_API int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *                     /* Client data for xCreate/xConnect */
);

/*
** CAPI3REF: Register A Virtual Table Implementation {F18210}
**
** This routine is identical to the sqlite3_create_module() method above,
** except that it allows a destructor function to be specified. It is
** even more experimental than the rest of the virtual tables API.
*/
SQLITE_API int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *,                    /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** CAPI3REF: Virtual Table Instance Object {F18010}
** KEYWORDS: sqlite3_vtab
**
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  Each subclass will
** be tailored to the specific needs of the module implementation.   The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
**
** Virtual tables methods can set an error message by assigning a
** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
** take care that any prior string is freed by a call to sqlite3_free()
** prior to assigning a new string to zErrMsg.  After the error message
** is delivered up to the client application, the string will be automatically
** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
** since virtual tables are commonly implemented in loadable extensions which
** do not have access to sqlite3MPrintf() or sqlite3Free().
*/
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* Used internally */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Virtual Table Cursor Object  {F18020}
** KEYWORDS: sqlite3_vtab_cursor
**
** Every module implementation uses a subclass of the following structure
** to describe cursors that point into the virtual table and are used
** to loop through the virtual table.  Cursors are created using the
** xOpen method of the module.  Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Declare The Schema Of A Virtual Table {F18280}
**
** The xCreate and xConnect methods of a module use the following API
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

/*
** CAPI3REF: Overload A Function For A Virtual Table {F18300}
**
** Virtual tables can provide alternative implementations of functions
** using the xFindFunction method.  But global versions of those functions
** must exist in order to be overloaded.
**
** This API makes sure a global version of a function with a particular
** name and number of parameters exists.  If no such function exists
** before this API is called, a new function is created.  The implementation
** of the new function always causes an exception to be thrown.  So
** the new function is not good for anything by itself.  Its only
** purpose is to be a place-holder function that can be overloaded
** by virtual tables.
**
** This API should be considered part of the virtual table interface,
** which is experimental and subject to change.
*/
SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);

/*
** The interface to the virtual-table mechanism defined above (back up
** to a comment remarkably similar to this one) is currently considered
** to be experimental.  The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.
**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB {F17800}
**
** An instance of this object represents an open BLOB on which
** incremental I/O can be preformed.
** Objects of this type are created by
** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the blob.
** The [sqlite3_blob_bytes()] interface returns the size of the
** blob in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O {F17810}
**
** This interfaces opens a handle to the blob located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words,  the same blob that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
** </pre> {END}
**
** If the flags parameter is non-zero, the blob is opened for 
** read and write access. If it is zero, the blob is opened for read 
** access.
**
** Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** is assigned when the database is connected using [ATTACH].
** For the main database file, the database name is "main".  For
** TEMP tables, the database name is "temp".
**
** On success, [SQLITE_OK] is returned and the new 
** [sqlite3_blob | blob handle] is written to *ppBlob. 
** Otherwise an error code is returned and 
** any value written to *ppBlob should not be used by the caller.
** This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
** 
** INVARIANTS:
**
** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
**          interface opens an [sqlite3_blob] object P on the blob
**          in column C of table T in database B on [database connection] D.
**
** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts
**          a new transaction on [database connection] D if that connection
**          is not already in a transaction.
**
** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob
**          for read and write access if and only if the F parameter
**          is non-zero.
**
** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on 
**          success and an appropriate [error code] on failure.
**
** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
SQLITE_API int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF:  Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | blob handle].
**
** Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in autocommit mode.
** If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit. {END}
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.
**
** INVARIANTS:
**
** {F17833} The [sqlite3_blob_close(P)] interface closes an
**          [sqlite3_blob] object P previously opened using
**          [sqlite3_blob_open()].
**
** {F17836} Closing an [sqlite3_blob] object using
**          [sqlite3_blob_close()] shall cause the current transaction to
**          commit if there are no other open [sqlite3_blob] objects
**          or [prepared statements] on the same [database connection] and
**          the [database connection] is in
**          [sqlite3_get_autocommit | autocommit mode].
**
** {F17839} The [sqlite3_blob_close(P)] interfaces closes the 
**          [sqlite3_blob] object P unconditionally, even if
**          [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].
**          
*/
SQLITE_API int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF:  Return The Size Of An Open BLOB {F17840}
**
** Return the size in bytes of the blob accessible via the open 
** [sqlite3_blob] object in its only argument.
**
** INVARIANTS:
**
** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size
**          in bytes of the BLOB that the [sqlite3_blob] object P
**          refers to.
*/
SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF:  Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open 
** [sqlite3_blob | blob-handle] into a caller supplied buffer.
** N bytes of data are copied into buffer
** Z from the open blob, starting at offset iOffset.
**
** If offset iOffset is less than N bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is read.  If N or iOffset is
** less than zero [SQLITE_ERROR] is returned and no data is read.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes
**          beginning at offset X from
**          the blob that [sqlite3_blob] object P refers to
**          and writes those N bytes into buffer Z.
**
** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully read into buffer Z.
**
** {F17865} If the requested read could not be completed,
**          the [sqlite3_blob_read(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error, where D is the
**          database handle that was used to open blob handle P.
*/
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF:  Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open 
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** If the [sqlite3_blob | blob-handle] passed as the first argument
** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
*** was zero), this function returns [SQLITE_READONLY].
**
** This function may only modify the contents of the blob; it is
** not possible to increase the size of a blob using this API.
** If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is written.  If n is
** less than zero [SQLITE_ERROR] is returned and no data is written.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes
**          from buffer Z into
**          the blob that [sqlite3_blob] object P refers to
**          beginning at an offset of X into the blob.
**
** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns
**          [SQLITE_READONLY] if the [sqlite3_blob] object P was
**          [sqlite3_blob_open | opened] for reading only.
**
** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully written into blob.
**
** {F17885} If the requested write could not be completed,
**          the [sqlite3_blob_write(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF:  Virtual File System Objects {F11200}
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most SQLite builds come with a
** single default VFS that is appropriate for the host computer.
** New VFSes can be registered and existing VFSes can be unregistered.
** The following interfaces are provided.
**
** The sqlite3_vfs_find() interface returns a pointer to 
** a VFS given its name.  Names are case sensitive.
** Names are zero-terminated UTF-8 strings.
** If there is no match, a NULL
** pointer is returned.  If zVfsName is NULL then the default 
** VFS is returned. 
**
** New VFSes are registered with sqlite3_vfs_register().
** Each new VFS becomes the default VFS if the makeDflt flag is set.
** The same VFS can be registered multiple times without injury.
** To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set.  If two different VFSes with the
** same name are registered, the behavior is undefined.  If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
** 
** Unregister a VFS with the sqlite3_vfs_unregister() interface.
** If the default VFS is unregistered, another VFS is chosen as
** the default.  The choice for the new VFS is arbitrary.
**
** INVARIANTS:
**
** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the
**          registered [sqlite3_vfs] object whose name exactly matches
**          the zero-terminated UTF-8 string N, or it returns NULL if
**          there is no match.
**
** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then
**          the function returns a pointer to the default [sqlite3_vfs]
**          object if there is one, or NULL if there is no default 
**          [sqlite3_vfs] object.
**
** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the
**          well-formed [sqlite3_vfs] object P using the name given
**          by the zName field of the object.
**
** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register
**          the same [sqlite3_vfs] object multiple times is a harmless no-op.
**
** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the
**          the [sqlite3_vfs] object P the default [sqlite3_vfs] object
**          if F is non-zero.
**
** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the
**          [sqlite3_vfs] object P so that it is no longer returned by
**          subsequent calls to [sqlite3_vfs_find()].
*/
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes {F17000}
**
** The SQLite core uses these routines for thread
** synchronization.  Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations 
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  The following
** implementations are available in the SQLite core:
**
** <ul>
** <li>   SQLITE_MUTEX_OS2
** <li>   SQLITE_MUTEX_PTHREAD
** <li>   SQLITE_MUTEX_W32
** <li>   SQLITE_MUTEX_NOOP
** </ul>
**
** The SQLITE_MUTEX_NOOP implementation is a set of routines 
** that does no real locking and is appropriate for use in 
** a single-threaded application.  The SQLITE_MUTEX_OS2,
** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
** are appropriate for use on os/2, unix, and windows.
** 
** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library.  The
** mutex interface routines defined here become external
** references in the SQLite library for which implementations
** must be provided by the application.  This facility allows an
** application that links against SQLite to provide its own mutex
** implementation without having to modify the SQLite core.
**
** {F17011} The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. {F17012} If it returns NULL
** that means that a mutex could not be allocated. {F17013} SQLite
** will unwind its stack and return an error. {F17014} The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** </ul> {END}
**
** {F17015} The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  {F17016} But SQLite will only request a recursive mutex in
** cases where it really needs one.  {END} If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex. {END}  Four static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** {F17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  {F17034} But for the static 
** mutex types, the same mutex is returned on every call that has
** the same type number. {END}
**
** {F17019} The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every
** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in 
** use when they are deallocated. {U17022} Attempting to deallocate a static
** mutex results in undefined behavior. {F17023} SQLite never deallocates
** a static mutex. {END}
**
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. {F17024} If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. {F17025}  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  {F17026} Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** {F17027} In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  {U17028} If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** {F17029} SQLite will never exhibit
** such behavior in its own use of mutexes. {END}
**
** Some systems (ex: windows95) do not the operation implemented by
** sqlite3_mutex_try().  On those systems, sqlite3_mutex_try() will
** always return SQLITE_BUSY.  {F17030} The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END}
**
** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  {U17032} The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.  {F17033} SQLite will
** never do either. {END}
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Verifcation Routines {F17080}
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements. {F17081} The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  {F17082} The core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  {U17087} External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** {F17083} These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread. {END}
**
** {X17084} The implementation is not required to provided versions of these
** routines that actually work.
** If the implementation does not provide working
** versions of these routines, it should at least provide stubs
** that always return true so that one does not get spurious
** assertion failures. {END}
**
** {F17085} If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1.  {END} This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist.  But the
** the reason the mutex does not exist is because the build is not
** using mutexes.  And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do.  {F17086} The sqlite3_mutex_notheld() 
** interface should also return 1 when given a NULL pointer.
*/
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Types {F17001}
**
** {F17002} The [sqlite3_mutex_alloc()] interface takes a single argument
** which is one of these integer constants. {END}
*/
#define SQLITE_MUTEX_FAST             0
#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MASTER    2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* sqlite3_release_memory() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

/*
** CAPI3REF: Low-Level Control Of Database Files {F11300}
**
** {F11301} The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. {F11302} The
** name of the database is the name assigned to the database by the
** <a href="lang_attach.html">ATTACH</a> SQL command that opened the
** database. {F11303} To control the main database file, use the name "main"
** or a NULL pointer. {F11304} The third and fourth parameters to this routine
** are passed directly through to the second and third parameters of
** the xFileControl method.  {F11305} The return value of the xFileControl
** method becomes the return value of this routine.
**
** {F11306} If the second parameter (zDbName) does not match the name of any
** open database file, then SQLITE_ERROR is returned. {F11307} This error
** code is not remembered and will not be recalled by [sqlite3_errcode()]
** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might
** also return SQLITE_ERROR.  {U11309} There is no way to distinguish between
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
** xFileControl method. {END}
**
** See also: [SQLITE_FCNTL_LOCKSTATE]
*/
SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);

/*
** CAPI3REF: Testing Interface {F11400}
**
** The sqlite3_test_control() interface is used to read out internal
** state of SQLite and to inject faults into SQLite for testing
** purposes.  The first parameter a operation code that determines
** the number, meaning, and operation of all subsequent parameters.
**
** This interface is not for use by applications.  It exists solely
** for verifying the correct operation of the SQLite library.  Depending
** on how the SQLite library is compiled, this interface might not exist.
**
** The details of the operation codes, their meanings, the parameters
** they take, and what they do are all subject to change without notice.
** Unlike most of the SQLite API, this function is not guaranteed to
** operate consistently from one release to the next.
*/
SQLITE_API int sqlite3_test_control(int op, ...);

/*
** CAPI3REF: Testing Interface Operation Codes {F11410}
**
** These constants are the valid operation code parameters used
** as the first argument to [sqlite3_test_control()].
**
** These parameters and their meansing are subject to change
** without notice.  These values are for testing purposes only.
** Applications should not use any of these parameters or the
** [sqlite3_test_control()] interface.
*/
#define SQLITE_TESTCTRL_FAULT_CONFIG             1
#define SQLITE_TESTCTRL_FAULT_FAILURES           2
#define SQLITE_TESTCTRL_FAULT_BENIGN_FAILURES    3
#define SQLITE_TESTCTRL_FAULT_PENDING            4
#define SQLITE_TESTCTRL_PRNG_SAVE                5
#define SQLITE_TESTCTRL_PRNG_RESTORE             6
#define SQLITE_TESTCTRL_PRNG_RESET               7
#define SQLITE_TESTCTRL_BITVEC_TEST              8


/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#if 0
}  /* End of the 'extern "C"' block */
#endif
#endif

/************** End of sqlite3.h *********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include hash.h in the middle of sqliteInt.h ******************/
/************** Begin file hash.h ********************************************/
/*
** 2001 September 22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the header file for the generic hash-table implemenation
** used in SQLite.
**
** $Id: hash.h,v 1.11 2007/09/04 14:31:47 danielk1977 Exp $
*/
#ifndef _SQLITE_HASH_H_
#define _SQLITE_HASH_H_

/* Forward declarations of structures. */
typedef struct Hash Hash;
typedef struct HashElem HashElem;

/* A complete hash table is an instance of the following structure.
** The internals of this structure are intended to be opaque -- client
** code should not attempt to access or modify the fields of this structure
** directly.  Change this structure only by using the routines below.
** However, many of the "procedures" and "functions" for modifying and
** accessing this structure are really macros, so we can't really make
** this structure opaque.
*/
struct Hash {
  char keyClass;          /* SQLITE_HASH_INT, _POINTER, _STRING, _BINARY */
  char copyKey;           /* True if copy of key made on insert */
  int count;              /* Number of entries in this table */
  int htsize;             /* Number of buckets in the hash table */
  HashElem *first;        /* The first element of the array */
  struct _ht {            /* the hash table */
    int count;               /* Number of entries with this hash */
    HashElem *chain;         /* Pointer to first entry with this hash */
  } *ht;
};

/* Each element in the hash table is an instance of the following 
** structure.  All elements are stored on a single doubly-linked list.
**
** Again, this structure is intended to be opaque, but it can't really
** be opaque because it is used by macros.
*/
struct HashElem {
  HashElem *next, *prev;   /* Next and previous elements in the table */
  void *data;              /* Data associated with this element */
  void *pKey; int nKey;    /* Key associated with this element */
};

/*
** There are 4 different modes of operation for a hash table:
**
**   SQLITE_HASH_INT         nKey is used as the key and pKey is ignored.
**
**   SQLITE_HASH_POINTER     pKey is used as the key and nKey is ignored.
**
**   SQLITE_HASH_STRING      pKey points to a string that is nKey bytes long
**                           (including the null-terminator, if any).  Case
**                           is ignored in comparisons.
**
**   SQLITE_HASH_BINARY      pKey points to binary data nKey bytes long. 
**                           memcmp() is used to compare keys.
**
** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY
** if the copyKey parameter to HashInit is 1.  
*/
/* #define SQLITE_HASH_INT       1 // NOT USED */
/* #define SQLITE_HASH_POINTER   2 // NOT USED */
#define SQLITE_HASH_STRING    3
#define SQLITE_HASH_BINARY    4

/*
** Access routines.  To delete, insert a NULL pointer.
*/
SQLITE_PRIVATE void sqlite3HashInit(Hash*, int keytype, int copyKey);
SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
SQLITE_PRIVATE HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey);
SQLITE_PRIVATE void sqlite3HashClear(Hash*);

/*
** Macros for looping over all elements of a hash table.  The idiom is
** like this:
**
**   Hash h;
**   HashElem *p;
**   ...
**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
**     SomeStructure *pData = sqliteHashData(p);
**     // do something with pData
**   }
*/
#define sqliteHashFirst(H)  ((H)->first)
#define sqliteHashNext(E)   ((E)->next)
#define sqliteHashData(E)   ((E)->data)
#define sqliteHashKey(E)    ((E)->pKey)
#define sqliteHashKeysize(E) ((E)->nKey)

/*
** Number of entries in a hash table
*/
#define sqliteHashCount(H)  ((H)->count)

#endif /* _SQLITE_HASH_H_ */

/************** End of hash.h ************************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include parse.h in the middle of sqliteInt.h *****************/
/************** Begin file parse.h *******************************************/
#define TK_SEMI                            1
#define TK_EXPLAIN                         2
#define TK_QUERY                           3
#define TK_PLAN                            4
#define TK_BEGIN                           5
#define TK_TRANSACTION                     6
#define TK_DEFERRED                        7
#define TK_IMMEDIATE                       8
#define TK_EXCLUSIVE                       9
#define TK_COMMIT                         10
#define TK_END                            11
#define TK_ROLLBACK                       12
#define TK_CREATE                         13
#define TK_TABLE                          14
#define TK_IF                             15
#define TK_NOT                            16
#define TK_EXISTS                         17
#define TK_TEMP                           18
#define TK_LP                             19
#define TK_RP                             20
#define TK_AS                             21
#define TK_COMMA                          22
#define TK_ID                             23
#define TK_ABORT                          24
#define TK_AFTER                          25
#define TK_ANALYZE                        26
#define TK_ASC                            27
#define TK_ATTACH                         28
#define TK_BEFORE                         29
#define TK_CASCADE                        30
#define TK_CAST                           31
#define TK_CONFLICT                       32
#define TK_DATABASE                       33
#define TK_DESC                           34
#define TK_DETACH                         35
#define TK_EACH                           36
#define TK_FAIL                           37
#define TK_FOR                            38
#define TK_IGNORE                         39
#define TK_INITIALLY                      40
#define TK_INSTEAD                        41
#define TK_LIKE_KW                        42
#define TK_MATCH                          43
#define TK_KEY                            44
#define TK_OF                             45
#define TK_OFFSET                         46
#define TK_PRAGMA                         47
#define TK_RAISE                          48
#define TK_REPLACE                        49
#define TK_RESTRICT                       50
#define TK_ROW                            51
#define TK_TRIGGER                        52
#define TK_VACUUM                         53
#define TK_VIEW                           54
#define TK_VIRTUAL                        55
#define TK_REINDEX                        56
#define TK_RENAME                         57
#define TK_CTIME_KW                       58
#define TK_ANY                            59
#define TK_OR                             60
#define TK_AND                            61
#define TK_IS                             62
#define TK_BETWEEN                        63
#define TK_IN                             64
#define TK_ISNULL                         65
#define TK_NOTNULL                        66
#define TK_NE                             67
#define TK_EQ                             68
#define TK_GT                             69
#define TK_LE                             70
#define TK_LT                             71
#define TK_GE                             72
#define TK_ESCAPE                         73
#define TK_BITAND                         74
#define TK_BITOR                          75
#define TK_LSHIFT                         76
#define TK_RSHIFT                         77
#define TK_PLUS                           78
#define TK_MINUS                          79
#define TK_STAR                           80
#define TK_SLASH                          81
#define TK_REM                            82
#define TK_CONCAT                         83
#define TK_COLLATE                        84
#define TK_UMINUS                         85
#define TK_UPLUS                          86
#define TK_BITNOT                         87
#define TK_STRING                         88
#define TK_JOIN_KW                        89
#define TK_CONSTRAINT                     90
#define TK_DEFAULT                        91
#define TK_NULL                           92
#define TK_PRIMARY                        93
#define TK_UNIQUE                         94
#define TK_CHECK                          95
#define TK_REFERENCES                     96
#define TK_AUTOINCR                       97
#define TK_ON                             98
#define TK_DELETE                         99
#define TK_UPDATE                         100
#define TK_INSERT                         101
#define TK_SET                            102
#define TK_DEFERRABLE                     103
#define TK_FOREIGN                        104
#define TK_DROP                           105
#define TK_UNION                          106
#define TK_ALL                            107
#define TK_EXCEPT                         108
#define TK_INTERSECT                      109
#define TK_SELECT                         110
#define TK_DISTINCT                       111
#define TK_DOT                            112
#define TK_FROM                           113
#define TK_JOIN                           114
#define TK_USING                          115
#define TK_ORDER                          116
#define TK_BY                             117
#define TK_GROUP                          118
#define TK_HAVING                         119
#define TK_LIMIT                          120
#define TK_WHERE                          121
#define TK_INTO                           122
#define TK_VALUES                         123
#define TK_INTEGER                        124
#define TK_FLOAT                          125
#define TK_BLOB                           126
#define TK_REGISTER                       127
#define TK_VARIABLE                       128
#define TK_CASE                           129
#define TK_WHEN                           130
#define TK_THEN                           131
#define TK_ELSE                           132
#define TK_INDEX                          133
#define TK_ALTER                          134
#define TK_TO                             135
#define TK_ADD                            136
#define TK_COLUMNKW                       137
#define TK_TO_TEXT                        138
#define TK_TO_BLOB                        139
#define TK_TO_NUMERIC                     140
#define TK_TO_INT                         141
#define TK_TO_REAL                        142
#define TK_END_OF_FILE                    143
#define TK_ILLEGAL                        144
#define TK_SPACE                          145
#define TK_UNCLOSED_STRING                146
#define TK_COMMENT                        147
#define TK_FUNCTION                       148
#define TK_COLUMN                         149
#define TK_AGG_FUNCTION                   150
#define TK_AGG_COLUMN                     151
#define TK_CONST_FUNC                     152

/************** End of parse.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stddef.h>

/*
** If compiling for a processor that lacks floating point support,
** substitute integer for floating-point
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite_int64
# define LONGDOUBLE_TYPE sqlite_int64
# ifndef SQLITE_BIG_DBL
#   define SQLITE_BIG_DBL (0x7fffffffffffffff)
# endif
# define SQLITE_OMIT_DATETIME_FUNCS 1
# define SQLITE_OMIT_TRACE 1
# undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
#endif
#ifndef SQLITE_BIG_DBL
# define SQLITE_BIG_DBL (1e99)
#endif

/*
** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
** afterward. Having this macro allows us to cause the C compiler 
** to omit code used by TEMP tables without messy #ifndef statements.
*/
#ifdef SQLITE_OMIT_TEMPDB
#define OMIT_TEMPDB 1
#else
#define OMIT_TEMPDB 0
#endif

/*
** If the following macro is set to 1, then NULL values are considered
** distinct when determining whether or not two entries are the same
** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
** is the way things are suppose to work.
**
** If the following macro is set to 0, the NULLs are indistinct for
** a UNIQUE index.  In this mode, you can only have a single NULL entry
** for a column declared UNIQUE.  This is the way Informix and SQL Server
** work.
*/
#define NULL_DISTINCT_FOR_UNIQUE 1

/*
** The "file format" number is an integer that is incremented whenever
** the VDBE-level file format changes.  The following macros define the
** the default file format for new databases and the maximum file format
** that the library can read.
*/
#define SQLITE_MAX_FILE_FORMAT 4
#ifndef SQLITE_DEFAULT_FILE_FORMAT
# define SQLITE_DEFAULT_FILE_FORMAT 1
#endif

/*
** Provide a default value for TEMP_STORE in case it is not specified
** on the command-line
*/
#ifndef TEMP_STORE
# define TEMP_STORE 1
#endif

/*
** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
#endif

/*
** Check to see if this machine uses EBCDIC.  (Yes, believe it or
** not, there are still machines out there that use EBCDIC.)
*/
#if 'A' == '\301'
# define SQLITE_EBCDIC 1
#else
# define SQLITE_ASCII 1
#endif

/*
** Integers of known sizes.  These typedefs might change for architectures
** where the sizes very.  Preprocessor macros are available so that the
** types can be conveniently redefined at compile-type.  Like this:
**
**         cc '-DUINTPTR_TYPE=long long int' ...
*/
#ifndef UINT32_TYPE
# ifdef HAVE_UINT32_T
#  define UINT32_TYPE uint32_t
# else
#  define UINT32_TYPE unsigned int
# endif
#endif
#ifndef UINT16_TYPE
# ifdef HAVE_UINT16_T
#  define UINT16_TYPE uint16_t
# else
#  define UINT16_TYPE unsigned short int
# endif
#endif
#ifndef INT16_TYPE
# ifdef HAVE_INT16_T
#  define INT16_TYPE int16_t
# else
#  define INT16_TYPE short int
# endif
#endif
#ifndef UINT8_TYPE
# ifdef HAVE_UINT8_T
#  define UINT8_TYPE uint8_t
# else
#  define UINT8_TYPE unsigned char
# endif
#endif
#ifndef INT8_TYPE
# ifdef HAVE_INT8_T
#  define INT8_TYPE int8_t
# else
#  define INT8_TYPE signed char
# endif
#endif
#ifndef LONGDOUBLE_TYPE
# define LONGDOUBLE_TYPE long double
#endif
typedef sqlite_int64 i64;          /* 8-byte signed integer */
typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
typedef INT16_TYPE i16;            /* 2-byte signed integer */
typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
typedef UINT8_TYPE i8;             /* 1-byte signed integer */

/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
#ifdef SQLITE_AMALGAMATION
SQLITE_PRIVATE const int sqlite3one;
#else
SQLITE_PRIVATE const int sqlite3one;
#endif
#if defined(i386) || defined(__i386__) || defined(_M_IX86)
# define SQLITE_BIGENDIAN    0
# define SQLITE_LITTLEENDIAN 1
# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
#else
# define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
#endif

/*
** Constants for the largest and smallest possible 64-bit signed integers.
** These macros are designed to work correctly on both 32-bit and 64-bit
** compilers.
*/
#define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
#define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)

/*
** An instance of the following structure is used to store the busy-handler
** callback for a given sqlite handle. 
**
** The sqlite.busyHandler member of the sqlite struct contains the busy
** callback for the database handle. Each pager opened via the sqlite
** handle is passed a pointer to sqlite.busyHandler. The busy-handler
** callback is currently invoked only from within pager.c.
*/
typedef struct BusyHandler BusyHandler;
struct BusyHandler {
  int (*xFunc)(void *,int);  /* The busy callback */
  void *pArg;                /* First arg to busy callback */
  int nBusy;                 /* Incremented with each busy call */
};

/*
** Name of the master database table.  The master database table
** is a special table that holds the names and attributes of all
** user tables and indices.
*/
#define MASTER_NAME       "sqlite_master"
#define TEMP_MASTER_NAME  "sqlite_temp_master"

/*
** The root-page of the master database table.
*/
#define MASTER_ROOT       1

/*
** The name of the schema table.
*/
#define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)

/*
** A convenience macro that returns the number of elements in
** an array.
*/
#define ArraySize(X)    (sizeof(X)/sizeof(X[0]))

/*
** Forward references to structures
*/
typedef struct AggInfo AggInfo;
typedef struct AuthContext AuthContext;
typedef struct Bitvec Bitvec;
typedef struct CollSeq CollSeq;
typedef struct Column Column;
typedef struct Db Db;
typedef struct Schema Schema;
typedef struct Expr Expr;
typedef struct ExprList ExprList;
typedef struct FKey FKey;
typedef struct FuncDef FuncDef;
typedef struct IdList IdList;
typedef struct Index Index;
typedef struct KeyClass KeyClass;
typedef struct KeyInfo KeyInfo;
typedef struct Module Module;
typedef struct NameContext NameContext;
typedef struct Parse Parse;
typedef struct Select Select;
typedef struct SrcList SrcList;
typedef struct StrAccum StrAccum;
typedef struct Table Table;
typedef struct TableLock TableLock;
typedef struct Token Token;
typedef struct TriggerStack TriggerStack;
typedef struct TriggerStep TriggerStep;
typedef struct Trigger Trigger;
typedef struct WhereInfo WhereInfo;
typedef struct WhereLevel WhereLevel;

/*
** Defer sourcing vdbe.h and btree.h until after the "u8" and 
** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
** pointer types (i.e. FuncDef) defined above.
*/
/************** Include btree.h in the middle of sqliteInt.h *****************/
/************** Begin file btree.h *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.98 2008/04/26 13:39:47 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
#define SQLITE_N_BTREE_META 10

/*
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
** it must be turned on for each database using "PRAGMA auto_vacuum = 1".
*/
#ifndef SQLITE_DEFAULT_AUTOVACUUM
  #define SQLITE_DEFAULT_AUTOVACUUM 0
#endif

#define BTREE_AUTOVACUUM_NONE 0        /* Do not do auto-vacuum */
#define BTREE_AUTOVACUUM_FULL 1        /* Do full auto-vacuum */
#define BTREE_AUTOVACUUM_INCR 2        /* Incremental vacuum */

/*
** Forward declarations of structure
*/
typedef struct Btree Btree;
typedef struct BtCursor BtCursor;
typedef struct BtShared BtShared;
typedef struct BtreeMutexArray BtreeMutexArray;

/*
** This structure records all of the Btrees that need to hold
** a mutex before we enter sqlite3VdbeExec().  The Btrees are
** are placed in aBtree[] in order of aBtree[]->pBt.  That way,
** we can always lock and unlock them all quickly.
*/
struct BtreeMutexArray {
  int nMutex;
  Btree *aBtree[SQLITE_MAX_ATTACHED+1];
};


SQLITE_PRIVATE int sqlite3BtreeOpen(
  const char *zFilename,   /* Name of database file to open */
  sqlite3 *db,             /* Associated database connection */
  Btree **,                /* Return open Btree* here */
  int flags,               /* Flags */
  int vfsFlags             /* Flags passed through to VFS open */
);

/* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the
** following values.
**
** NOTE:  These values must match the corresponding PAGER_ values in
** pager.h.
*/
#define BTREE_OMIT_JOURNAL  1  /* Do not use journal.  No argument */
#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
#define BTREE_MEMORY        4  /* In-memory DB.  No argument */
#define BTREE_READONLY      8  /* Open the database in read-only mode */
#define BTREE_READWRITE    16  /* Open for both reading and writing */
#define BTREE_CREATE       32  /* Create the database if it does not exist */

/* Additional values for the 4th argument of sqlite3BtreeOpen that
** are not associated with PAGER_ values.
*/
#define BTREE_PRIVATE      64  /* Never share with other connections */

SQLITE_PRIVATE int sqlite3BtreeClose(Btree*);
SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree*,int);
SQLITE_PRIVATE int sqlite3BtreeSetSafetyLevel(Btree*,int,int);
SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree*);
SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree*,int,int);
SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*);
SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree*,int);
SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree*);
SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int);
SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *);
SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int);
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree*);
SQLITE_PRIVATE int sqlite3BtreeCommit(Btree*);
SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*);
SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree*);
SQLITE_PRIVATE int sqlite3BtreeCommitStmt(Btree*);
SQLITE_PRIVATE int sqlite3BtreeRollbackStmt(Btree*);
SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree*, int*, int flags);
SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree*);
SQLITE_PRIVATE int sqlite3BtreeIsInStmt(Btree*);
SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree*);
SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *);
SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *, int, u8);

SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *);
SQLITE_PRIVATE const char *sqlite3BtreeGetDirname(Btree *);
SQLITE_PRIVATE const char *sqlite3BtreeGetJournalname(Btree *);
SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *, Btree *);

SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *);

/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
** of the following flags:
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_ZERODATA   2    /* Table has keys only - no data */
#define BTREE_LEAFDATA   4    /* Data stored in leaves only.  Implies INTKEY */

SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree*, int, int*);
SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int);
SQLITE_PRIVATE int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree*, int);

struct UnpackedRecord;  /* Forward declaration.  Definition in vdbeaux.c. */

SQLITE_PRIVATE int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */
  int wrFlag,                          /* 1 for writing.  0 for read-only */
  struct KeyInfo*,                     /* First argument to compare function */
  BtCursor *pCursor                    /* Space to write cursor structure */
);
SQLITE_PRIVATE int sqlite3BtreeCursorSize(void);

SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeMoveto(
  BtCursor*,
  const void *pKey,
  struct UnpackedRecord *pUnKey,
  i64 nKey,
  int bias,
  int *pRes
);
SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias);
SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeFlags(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
SQLITE_PRIVATE sqlite3 *sqlite3BtreeCursorDb(const BtCursor*);
SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
SQLITE_PRIVATE int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);

SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
SQLITE_PRIVATE void sqlite3BtreeCacheOverflow(BtCursor *);

#ifdef SQLITE_TEST
SQLITE_PRIVATE int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
SQLITE_PRIVATE void sqlite3BtreeCursorList(Btree*);
SQLITE_PRIVATE int sqlite3BtreePageDump(Btree*, int, int recursive);
#endif

/*
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
SQLITE_PRIVATE   void sqlite3BtreeEnter(Btree*);
SQLITE_PRIVATE   void sqlite3BtreeLeave(Btree*);
SQLITE_PRIVATE   int sqlite3BtreeHoldsMutex(Btree*);
SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
SQLITE_PRIVATE   void sqlite3BtreeLeaveCursor(BtCursor*);
SQLITE_PRIVATE   void sqlite3BtreeEnterAll(sqlite3*);
SQLITE_PRIVATE   void sqlite3BtreeLeaveAll(sqlite3*);
SQLITE_PRIVATE   int sqlite3BtreeHoldsAllMutexes(sqlite3*);
SQLITE_PRIVATE   void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
SQLITE_PRIVATE   void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
SQLITE_PRIVATE   void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
#else
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeHoldsMutex(X) 1
# define sqlite3BtreeEnterCursor(X)
# define sqlite3BtreeLeaveCursor(X)
# define sqlite3BtreeEnterAll(X)
# define sqlite3BtreeLeaveAll(X)
# define sqlite3BtreeHoldsAllMutexes(X) 1
# define sqlite3BtreeMutexArrayEnter(X)
# define sqlite3BtreeMutexArrayLeave(X)
# define sqlite3BtreeMutexArrayInsert(X,Y)
#endif


#endif /* _BTREE_H_ */

/************** End of btree.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include vdbe.h in the middle of sqliteInt.h ******************/
/************** Begin file vdbe.h ********************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.131 2008/05/01 17:03:49 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
** in the source file sqliteVdbe.c are allowed to see the insides
** of this structure.
*/
typedef struct Vdbe Vdbe;

/*
** The names of the following types declared in vdbeInt.h are required
** for the VdbeOp definition.
*/
typedef struct VdbeFunc VdbeFunc;
typedef struct Mem Mem;
typedef struct UnpackedRecord UnpackedRecord;

/*
** A single instruction of the virtual machine has an opcode
** and as many as three operands.  The instruction is recorded
** as an instance of the following structure:
*/
struct VdbeOp {
  u8 opcode;          /* What operation to perform */
  signed char p4type; /* One of the P4_xxx constants for p4 */
  u8 opflags;         /* Not currently used */
  u8 p5;              /* Fifth parameter is an unsigned character */
  int p1;             /* First operand */
  int p2;             /* Second parameter (often the jump destination) */
  int p3;             /* The third parameter */
  union {             /* forth parameter */
    int i;                 /* Integer value if p4type==P4_INT32 */
    void *p;               /* Generic pointer */
    char *z;               /* Pointer to data for string (char array) types */
    i64 *pI64;             /* Used when p4type is P4_INT64 */
    double *pReal;         /* Used when p4type is P4_REAL */
    FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
    Mem *pMem;             /* Used when p4type is P4_MEM */
    sqlite3_vtab *pVtab;   /* Used when p4type is P4_VTAB */
    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
  } p4;
#ifdef SQLITE_DEBUG
  char *zComment;     /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;            /* Number of times this instruction was executed */
  long long cycles;   /* Total time spend executing this instruction */
#endif
};
typedef struct VdbeOp VdbeOp;

/*
** A smaller version of VdbeOp used for the VdbeAddOpList() function because
** it takes up less space.
*/
struct VdbeOpList {
  u8 opcode;          /* What operation to perform */
  signed char p1;     /* First operand */
  signed char p2;     /* Second parameter (often the jump destination) */
  signed char p3;     /* Third parameter */
};
typedef struct VdbeOpList VdbeOpList;

/*
** Allowed values of VdbeOp.p3type
*/
#define P4_NOTUSED    0   /* The P4 parameter is not used */
#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
#define P4_STATIC   (-2)  /* Pointer to a static string */
#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
#define P4_TRANSIENT (-9) /* P4 is a pointer to a transient string */
#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */

/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
*/
#define P4_KEYINFO_HANDOFF (-9)

/*
** The Vdbe.aColName array contains 5n Mem structures, where n is the 
** number of columns of data returned by the statement.
*/
#define COLNAME_NAME     0
#define COLNAME_DECLTYPE 1
#define COLNAME_DATABASE 2
#define COLNAME_TABLE    3
#define COLNAME_COLUMN   4
#ifdef SQLITE_ENABLE_COLUMN_METADATA
# define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
#else
# ifdef SQLITE_OMIT_DECLTYPE
#   define COLNAME_N      1      /* Store only the name */
# else
#   define COLNAME_N      2      /* Store the name and decltype */
# endif
#endif

/*
** The following macro converts a relative address in the p2 field
** of a VdbeOp structure into a negative number so that 
** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
** the macro again restores the address.
*/
#define ADDR(X)  (-1-(X))

/*
** The makefile scans the vdbe.c source file and creates the "opcodes.h"
** header file that defines a number for each opcode used by the VDBE.
*/
/************** Include opcodes.h in the middle of vdbe.h ********************/
/************** Begin file opcodes.h *****************************************/
/* Automatically generated.  Do not edit */
/* See the mkopcodeh.awk script for details */
#define OP_VNext                                1
#define OP_Affinity                             2
#define OP_Column                               3
#define OP_SetCookie                            4
#define OP_Real                               125   /* same as TK_FLOAT    */
#define OP_Sequence                             5
#define OP_MoveGt                               6
#define OP_Ge                                  72   /* same as TK_GE       */
#define OP_RowKey                               7
#define OP_SCopy                                8
#define OP_Eq                                  68   /* same as TK_EQ       */
#define OP_OpenWrite                            9
#define OP_NotNull                             66   /* same as TK_NOTNULL  */
#define OP_If                                  10
#define OP_ToInt                              141   /* same as TK_TO_INT   */
#define OP_String8                             88   /* same as TK_STRING   */
#define OP_VRowid                              11
#define OP_CollSeq                             12
#define OP_OpenRead                            13
#define OP_Expire                              14
#define OP_AutoCommit                          15
#define OP_Gt                                  69   /* same as TK_GT       */
#define OP_IntegrityCk                         17
#define OP_Sort                                18
#define OP_Copy                                19
#define OP_Trace                               20
#define OP_Function                            21
#define OP_IfNeg                               22
#define OP_And                                 61   /* same as TK_AND      */
#define OP_Subtract                            79   /* same as TK_MINUS    */
#define OP_Noop                                23
#define OP_Return                              24
#define OP_Remainder                           82   /* same as TK_REM      */
#define OP_NewRowid                            25
#define OP_Multiply                            80   /* same as TK_STAR     */
#define OP_Variable                            26
#define OP_String                              27
#define OP_RealAffinity                        28
#define OP_VRename                             29
#define OP_ParseSchema                         30
#define OP_VOpen                               31
#define OP_Close                               32
#define OP_CreateIndex                         33
#define OP_IsUnique                            34
#define OP_NotFound                            35
#define OP_Int64                               36
#define OP_MustBeInt                           37
#define OP_Halt                                38
#define OP_Rowid                               39
#define OP_IdxLT                               40
#define OP_AddImm                              41
#define OP_Statement                           42
#define OP_RowData                             43
#define OP_MemMax                              44
#define OP_Or                                  60   /* same as TK_OR       */
#define OP_NotExists                           45
#define OP_Gosub                               46
#define OP_Divide                              81   /* same as TK_SLASH    */
#define OP_Integer                             47
#define OP_ToNumeric                          140   /* same as TK_TO_NUMERIC*/
#define OP_Prev                                48
#define OP_Concat                              83   /* same as TK_CONCAT   */
#define OP_BitAnd                              74   /* same as TK_BITAND   */
#define OP_VColumn                             49
#define OP_CreateTable                         50
#define OP_Last                                51
#define OP_IsNull                              65   /* same as TK_ISNULL   */
#define OP_IncrVacuum                          52
#define OP_IdxRowid                            53
#define OP_ShiftRight                          77   /* same as TK_RSHIFT   */
#define OP_ResetCount                          54
#define OP_FifoWrite                           55
#define OP_ContextPush                         56
#define OP_DropTrigger                         57
#define OP_DropIndex                           58
#define OP_IdxGE                               59
#define OP_IdxDelete                           62
#define OP_Vacuum                              63
#define OP_MoveLe                              64
#define OP_IfNot                               73
#define OP_DropTable                           84
#define OP_MakeRecord                          85
#define OP_ToBlob                             139   /* same as TK_TO_BLOB  */
#define OP_ResultRow                           86
#define OP_Delete                              89
#define OP_AggFinal                            90
#define OP_ShiftLeft                           76   /* same as TK_LSHIFT   */
#define OP_Goto                                91
#define OP_TableLock                           92
#define OP_FifoRead                            93
#define OP_Clear                               94
#define OP_MoveLt                              95
#define OP_Le                                  70   /* same as TK_LE       */
#define OP_VerifyCookie                        96
#define OP_AggStep                             97
#define OP_ToText                             138   /* same as TK_TO_TEXT  */
#define OP_Not                                 16   /* same as TK_NOT      */
#define OP_ToReal                             142   /* same as TK_TO_REAL  */
#define OP_SetNumColumns                       98
#define OP_Transaction                         99
#define OP_VFilter                            100
#define OP_Ne                                  67   /* same as TK_NE       */
#define OP_VDestroy                           101
#define OP_ContextPop                         102
#define OP_BitOr                               75   /* same as TK_BITOR    */
#define OP_Next                               103
#define OP_IdxInsert                          104
#define OP_Lt                                  71   /* same as TK_LT       */
#define OP_Insert                             105
#define OP_Destroy                            106
#define OP_ReadCookie                         107
#define OP_ForceInt                           108
#define OP_LoadAnalysis                       109
#define OP_Explain                            110
#define OP_OpenPseudo                         111
#define OP_OpenEphemeral                      112
#define OP_Null                               113
#define OP_Move                               114
#define OP_Blob                               115
#define OP_Add                                 78   /* same as TK_PLUS     */
#define OP_Rewind                             116
#define OP_MoveGe                             117
#define OP_VBegin                             118
#define OP_VUpdate                            119
#define OP_IfZero                             120
#define OP_BitNot                              87   /* same as TK_BITNOT   */
#define OP_VCreate                            121
#define OP_Found                              122
#define OP_IfPos                              123
#define OP_NullRow                            124

/* The following opcode values are never used */
#define OP_NotUsed_126                        126
#define OP_NotUsed_127                        127
#define OP_NotUsed_128                        128
#define OP_NotUsed_129                        129
#define OP_NotUsed_130                        130
#define OP_NotUsed_131                        131
#define OP_NotUsed_132                        132
#define OP_NotUsed_133                        133
#define OP_NotUsed_134                        134
#define OP_NotUsed_135                        135
#define OP_NotUsed_136                        136
#define OP_NotUsed_137                        137


/* Properties such as "out2" or "jump" that are specified in
** comments following the "case" for each opcode in the vdbe.c
** are encoded into bitvectors as follows:
*/
#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
#define OPFLG_OUT2_PRERELEASE 0x0002  /* out2-prerelease: */
#define OPFLG_IN1             0x0004  /* in1:   P1 is an input */
#define OPFLG_IN2             0x0008  /* in2:   P2 is an input */
#define OPFLG_IN3             0x0010  /* in3:   P3 is an input */
#define OPFLG_OUT3            0x0020  /* out3:  P3 is an output */
#define OPFLG_INITIALIZER {\
/*   0 */ 0x00, 0x01, 0x00, 0x00, 0x10, 0x02, 0x11, 0x00,\
/*   8 */ 0x00, 0x00, 0x05, 0x02, 0x00, 0x00, 0x00, 0x00,\
/*  16 */ 0x04, 0x00, 0x01, 0x00, 0x00, 0x00, 0x05, 0x00,\
/*  24 */ 0x00, 0x02, 0x02, 0x02, 0x04, 0x00, 0x00, 0x00,\
/*  32 */ 0x00, 0x02, 0x11, 0x11, 0x02, 0x05, 0x00, 0x02,\
/*  40 */ 0x11, 0x04, 0x00, 0x00, 0x0c, 0x11, 0x01, 0x02,\
/*  48 */ 0x01, 0x00, 0x02, 0x01, 0x01, 0x02, 0x00, 0x04,\
/*  56 */ 0x00, 0x00, 0x00, 0x11, 0x2c, 0x2c, 0x00, 0x00,\
/*  64 */ 0x11, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\
/*  72 */ 0x15, 0x05, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,\
/*  80 */ 0x2c, 0x2c, 0x2c, 0x2c, 0x00, 0x00, 0x00, 0x04,\
/*  88 */ 0x02, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x11,\
/*  96 */ 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x01,\
/* 104 */ 0x08, 0x00, 0x02, 0x02, 0x05, 0x00, 0x00, 0x00,\
/* 112 */ 0x00, 0x02, 0x00, 0x02, 0x01, 0x11, 0x00, 0x00,\
/* 120 */ 0x05, 0x00, 0x11, 0x05, 0x00, 0x02, 0x00, 0x00,\
/* 128 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 136 */ 0x00, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04,}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(sqlite3*);
SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   void sqlite3VdbeTrace(Vdbe*,FILE*);
#endif
SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe*, int);
SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, int);
SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*);
SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n);
SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
SQLITE_PRIVATE int sqlite3VdbeReleaseMemory(int);
#endif
SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,void*,int);
SQLITE_PRIVATE void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord*);
SQLITE_PRIVATE int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);


#ifndef NDEBUG
SQLITE_PRIVATE   void sqlite3VdbeComment(Vdbe*, const char*, ...);
# define VdbeComment(X)  sqlite3VdbeComment X
#else
# define VdbeComment(X)
#endif

#endif

/************** End of vdbe.h ************************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include pager.h in the middle of sqliteInt.h *****************/
/************** Begin file pager.h *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.72 2008/05/01 17:03:49 drh Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** The type used to represent a page number.  The first page in a file
** is called page 1.  0 is used to represent "not a page".
*/
typedef unsigned int Pgno;

/*
** Each open file is managed by a separate instance of the "Pager" structure.
*/
typedef struct Pager Pager;

/*
** Handle type for pages.
*/
typedef struct PgHdr DbPage;

/*
** Allowed values for the flags parameter to sqlite3PagerOpen().
**
** NOTE: This values must match the corresponding BTREE_ values in btree.h.
*/
#define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */

/*
** Valid values for the second argument to sqlite3PagerLockingMode().
*/
#define PAGER_LOCKINGMODE_QUERY      -1
#define PAGER_LOCKINGMODE_NORMAL      0
#define PAGER_LOCKINGMODE_EXCLUSIVE   1

/*
** Valid values for the second argument to sqlite3PagerJournalMode().
*/
#define PAGER_JOURNALMODE_QUERY      -1
#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */

/*
** See source code comments for a detailed description of the following
** routines:
*/
SQLITE_PRIVATE int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, int,int,int);
SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(Pager*, BusyHandler *pBusyHandler);
SQLITE_PRIVATE void sqlite3PagerSetDestructor(Pager*, void(*)(DbPage*,int));
SQLITE_PRIVATE void sqlite3PagerSetReiniter(Pager*, void(*)(DbPage*,int));
SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u16*);
SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int);
SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);
SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager);
SQLITE_PRIVATE int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
SQLITE_PRIVATE int sqlite3PagerRef(DbPage*);
SQLITE_PRIVATE int sqlite3PagerUnref(DbPage*);
SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*);
SQLITE_PRIVATE int sqlite3PagerPagecount(Pager*);
SQLITE_PRIVATE int sqlite3PagerTruncate(Pager*,Pgno);
SQLITE_PRIVATE int sqlite3PagerBegin(DbPage*, int exFlag);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno, int);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*);
SQLITE_PRIVATE int sqlite3PagerRollback(Pager*);
SQLITE_PRIVATE int sqlite3PagerIsreadonly(Pager*);
SQLITE_PRIVATE int sqlite3PagerStmtBegin(Pager*);
SQLITE_PRIVATE int sqlite3PagerStmtCommit(Pager*);
SQLITE_PRIVATE int sqlite3PagerStmtRollback(Pager*);
SQLITE_PRIVATE void sqlite3PagerDontRollback(DbPage*);
SQLITE_PRIVATE void sqlite3PagerDontWrite(DbPage*);
SQLITE_PRIVATE int sqlite3PagerRefcount(Pager*);
SQLITE_PRIVATE void sqlite3PagerSetSafetyLevel(Pager*,int,int);
SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*);
SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager*);
SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*);
SQLITE_PRIVATE const char *sqlite3PagerDirname(Pager*);
SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*);
SQLITE_PRIVATE int sqlite3PagerNosync(Pager*);
SQLITE_PRIVATE int sqlite3PagerMovepage(Pager*,DbPage*,Pgno);
SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *); 
SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *); 
SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *, int);
SQLITE_PRIVATE int sqlite3PagerJournalMode(Pager *, int);
SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*);
SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager);

#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
SQLITE_PRIVATE   int sqlite3PagerReleaseMemory(int);
#endif

#ifdef SQLITE_HAS_CODEC
SQLITE_PRIVATE   void sqlite3PagerSetCodec(Pager*,void*(*)(void*,void*,Pgno,int),void*);
#endif

#if !defined(NDEBUG) || defined(SQLITE_TEST)
SQLITE_PRIVATE   Pgno sqlite3PagerPagenumber(DbPage*);
SQLITE_PRIVATE   int sqlite3PagerIswriteable(DbPage*);
#endif

#ifdef SQLITE_TEST
SQLITE_PRIVATE   int *sqlite3PagerStats(Pager*);
SQLITE_PRIVATE   void sqlite3PagerRefdump(Pager*);
#endif

#ifdef SQLITE_TEST
void disable_simulated_io_errors(void);
void enable_simulated_io_errors(void);
#else
# define disable_simulated_io_errors()
# define enable_simulated_io_errors()
#endif

#endif /* _PAGER_H_ */

/************** End of pager.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/************** Include os.h in the middle of sqliteInt.h ********************/
/************** Begin file os.h **********************************************/
/*
** 2001 September 16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This header file (together with is companion C source-code file
** "os.c") attempt to abstract the underlying operating system so that
** the SQLite library will work on both POSIX and windows systems.
**
** This header file is #include-ed by sqliteInt.h and thus ends up
** being included by every source file.
*/
#ifndef _SQLITE_OS_H_
#define _SQLITE_OS_H_

/*
** Figure out if we are dealing with Unix, Windows, or some other
** operating system.  After the following block of preprocess macros,
** all of OS_UNIX, OS_WIN, OS_OS2, and OS_OTHER will defined to either
** 1 or 0.  One of the four will be 1.  The other three will be 0.
*/
#if defined(OS_OTHER)
# if OS_OTHER==1
#   undef OS_UNIX
#   define OS_UNIX 0
#   undef OS_WIN
#   define OS_WIN 0
#   undef OS_OS2
#   define OS_OS2 0
# else
#   undef OS_OTHER
# endif
#endif
#if !defined(OS_UNIX) && !defined(OS_OTHER)
# define OS_OTHER 0
# ifndef OS_WIN
#   if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__)
#     define OS_WIN 1
#     define OS_UNIX 0
#     define OS_OS2 0
#   elif defined(__EMX__) || defined(_OS2) || defined(OS2) || defined(_OS2_) || defined(__OS2__)
#     define OS_WIN 0
#     define OS_UNIX 0
#     define OS_OS2 1
#   else
#     define OS_WIN 0
#     define OS_UNIX 1
#     define OS_OS2 0
#  endif
# else
#  define OS_UNIX 0
#  define OS_OS2 0
# endif
#else
# ifndef OS_WIN
#  define OS_WIN 0
# endif
#endif



/*
** Define the maximum size of a temporary filename
*/
#if OS_WIN
# include <windows.h>
# define SQLITE_TEMPNAME_SIZE (MAX_PATH+50)
#elif OS_OS2
# if (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3) && defined(OS2_HIGH_MEMORY)
#  include <os2safe.h> /* has to be included before os2.h for linking to work */
# endif
# define INCL_DOSDATETIME
# define INCL_DOSFILEMGR
# define INCL_DOSERRORS
# define INCL_DOSMISC
# define INCL_DOSPROCESS
# define INCL_DOSMODULEMGR
# define INCL_DOSSEMAPHORES
# include <os2.h>
# include <uconv.h>
# define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP)
#else
# define SQLITE_TEMPNAME_SIZE 200
#endif

/* If the SET_FULLSYNC macro is not defined above, then make it
** a no-op
*/
#ifndef SET_FULLSYNC
# define SET_FULLSYNC(x,y)
#endif

/*
** The default size of a disk sector
*/
#ifndef SQLITE_DEFAULT_SECTOR_SIZE
# define SQLITE_DEFAULT_SECTOR_SIZE 512
#endif

/*
** Temporary files are named starting with this prefix followed by 16 random
** alphanumeric characters, and no file extension. They are stored in the
** OS's standard temporary file directory, and are deleted prior to exit.
** If sqlite is being embedded in another program, you may wish to change the
** prefix to reflect your program's name, so that if your program exits
** prematurely, old temporary files can be easily identified. This can be done
** using -DSQLITE_TEMP_FILE_PREFIX=myprefix_ on the compiler command line.
**
** 2006-10-31:  The default prefix used to be "sqlite_".  But then
** Mcafee started using SQLite in their anti-virus product and it
** started putting files with the "sqlite" name in the c:/temp folder.
** This annoyed many windows users.  Those users would then do a 
** Google search for "sqlite", find the telephone numbers of the
** developers and call to wake them up at night and complain.
** For this reason, the default name prefix is changed to be "sqlite" 
** spelled backwards.  So the temp files are still identified, but
** anybody smart enough to figure out the code is also likely smart
** enough to know that calling the developer will not help get rid
** of the file.
*/
#ifndef SQLITE_TEMP_FILE_PREFIX
# define SQLITE_TEMP_FILE_PREFIX "etilqs_"
#endif

/*
** The following values may be passed as the second argument to
** sqlite3OsLock(). The various locks exhibit the following semantics:
**
** SHARED:    Any number of processes may hold a SHARED lock simultaneously.
** RESERVED:  A single process may hold a RESERVED lock on a file at
**            any time. Other processes may hold and obtain new SHARED locks.
** PENDING:   A single process may hold a PENDING lock on a file at
**            any one time. Existing SHARED locks may persist, but no new
**            SHARED locks may be obtained by other processes.
** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks.
**
** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a
** process that requests an EXCLUSIVE lock may actually obtain a PENDING
** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to
** sqlite3OsLock().
*/
#define NO_LOCK         0
#define SHARED_LOCK     1
#define RESERVED_LOCK   2
#define PENDING_LOCK    3
#define EXCLUSIVE_LOCK  4

/*
** File Locking Notes:  (Mostly about windows but also some info for Unix)
**
** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because
** those functions are not available.  So we use only LockFile() and
** UnlockFile().
**
** LockFile() prevents not just writing but also reading by other processes.
** A SHARED_LOCK is obtained by locking a single randomly-chosen 
** byte out of a specific range of bytes. The lock byte is obtained at 
** random so two separate readers can probably access the file at the 
** same time, unless they are unlucky and choose the same lock byte.
** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range.
** There can only be one writer.  A RESERVED_LOCK is obtained by locking
** a single byte of the file that is designated as the reserved lock byte.
** A PENDING_LOCK is obtained by locking a designated byte different from
** the RESERVED_LOCK byte.
**
** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available,
** which means we can use reader/writer locks.  When reader/writer locks
** are used, the lock is placed on the same range of bytes that is used
** for probabilistic locking in Win95/98/ME.  Hence, the locking scheme
** will support two or more Win95 readers or two or more WinNT readers.
** But a single Win95 reader will lock out all WinNT readers and a single
** WinNT reader will lock out all other Win95 readers.
**
** The following #defines specify the range of bytes used for locking.
** SHARED_SIZE is the number of bytes available in the pool from which
** a random byte is selected for a shared lock.  The pool of bytes for
** shared locks begins at SHARED_FIRST. 
**
** These #defines are available in sqlite_aux.h so that adaptors for
** connecting SQLite to other operating systems can use the same byte
** ranges for locking.  In particular, the same locking strategy and
** byte ranges are used for Unix.  This leaves open the possiblity of having
** clients on win95, winNT, and unix all talking to the same shared file
** and all locking correctly.  To do so would require that samba (or whatever
** tool is being used for file sharing) implements locks correctly between
** windows and unix.  I'm guessing that isn't likely to happen, but by
** using the same locking range we are at least open to the possibility.
**
** Locking in windows is manditory.  For this reason, we cannot store
** actual data in the bytes used for locking.  The pager never allocates
** the pages involved in locking therefore.  SHARED_SIZE is selected so
** that all locks will fit on a single page even at the minimum page size.
** PENDING_BYTE defines the beginning of the locks.  By default PENDING_BYTE
** is set high so that we don't have to allocate an unused page except
** for very large databases.  But one should test the page skipping logic 
** by setting PENDING_BYTE low and running the entire regression suite.
**
** Changing the value of PENDING_BYTE results in a subtly incompatible
** file format.  Depending on how it is changed, you might not notice
** the incompatibility right away, even running a full regression test.
** The default location of PENDING_BYTE is the first byte past the
** 1GB boundary.
**
*/
#ifndef SQLITE_TEST
#define PENDING_BYTE      0x40000000  /* First byte past the 1GB boundary */
#else
SQLITE_API extern unsigned int sqlite3_pending_byte;
#define PENDING_BYTE sqlite3_pending_byte
#endif

#define RESERVED_BYTE     (PENDING_BYTE+1)
#define SHARED_FIRST      (PENDING_BYTE+2)
#define SHARED_SIZE       510

/* 
** Functions for accessing sqlite3_file methods 
*/
SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file*);
SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);
SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);
SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file*, i64 size);
SQLITE_PRIVATE int sqlite3OsSync(sqlite3_file*, int);
SQLITE_PRIVATE int sqlite3OsFileSize(sqlite3_file*, i64 *pSize);
SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file*, int);
SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file*, int);
SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id);
SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file*,int,void*);
SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id);
SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id);

/* 
** Functions for accessing sqlite3_vfs methods 
*/
SQLITE_PRIVATE int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file*, int, int *);
SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *, const char *, int);
SQLITE_PRIVATE int sqlite3OsAccess(sqlite3_vfs *, const char *, int);
SQLITE_PRIVATE int sqlite3OsGetTempname(sqlite3_vfs *, int, char *);
SQLITE_PRIVATE int sqlite3OsFullPathname(sqlite3_vfs *, const char *, int, char *);
SQLITE_PRIVATE void *sqlite3OsDlOpen(sqlite3_vfs *, const char *);
SQLITE_PRIVATE void sqlite3OsDlError(sqlite3_vfs *, int, char *);
SQLITE_PRIVATE void *sqlite3OsDlSym(sqlite3_vfs *, void *, const char *);
SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *, void *);
SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *, int);
SQLITE_PRIVATE int sqlite3OsCurrentTime(sqlite3_vfs *, double*);

/*
** Convenience functions for opening and closing files using 
** sqlite3_malloc() to obtain space for the file-handle structure.
*/
SQLITE_PRIVATE int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);
SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);

/*
** Each OS-specific backend defines an instance of the following
** structure for returning a pointer to its sqlite3_vfs.  If OS_OTHER
** is defined (meaning that the application-defined OS interface layer
** is used) then there is no default VFS.   The application must
** register one or more VFS structures using sqlite3_vfs_register()
** before attempting to use SQLite.
*/
SQLITE_PRIVATE sqlite3_vfs *sqlite3OsDefaultVfs(void);

#endif /* _SQLITE_OS_H_ */

/************** End of os.h **************************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include mutex.h in the middle of sqliteInt.h *****************/
/************** Begin file mutex.h *******************************************/
/*
** 2007 August 28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains the common header for all mutex implementations.
** The sqliteInt.h header #includes this file so that it is available
** to all source files.  We break it out in an effort to keep the code
** better organized.
**
** NOTE:  source files should *not* #include this header file directly.
** Source files should #include the sqliteInt.h file and let that file
** include this one indirectly.
**
** $Id: mutex.h,v 1.2 2007/08/30 14:10:30 drh Exp $
*/


#ifdef SQLITE_MUTEX_APPDEF
/*
** If SQLITE_MUTEX_APPDEF is defined, then this whole module is
** omitted and equivalent functionality must be provided by the
** application that links against the SQLite library.
*/
#else
/*
** Figure out what version of the code to use.  The choices are
**
**   SQLITE_MUTEX_NOOP         For single-threaded applications that
**                             do not desire error checking.
**
**   SQLITE_MUTEX_NOOP_DEBUG   For single-threaded applications with
**                             error checking to help verify that mutexes
**                             are being used correctly even though they
**                             are not needed.  Used when SQLITE_DEBUG is
**                             defined on single-threaded builds.
**
**   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
**
**   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
**
**   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
*/
#define SQLITE_MUTEX_NOOP 1   /* The default */
#if defined(SQLITE_DEBUG) && !SQLITE_THREADSAFE
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_NOOP_DEBUG
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_UNIX
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_PTHREADS
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_WIN
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_W32
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_OS2
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_OS2
#endif

#ifdef SQLITE_MUTEX_NOOP
/*
** If this is a no-op implementation, implement everything as macros.
*/
#define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
#define sqlite3_mutex_free(X)
#define sqlite3_mutex_enter(X)
#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)
#define sqlite3_mutex_held(X)     1
#define sqlite3_mutex_notheld(X)  1
#endif

#endif /* SQLITE_MUTEX_APPDEF */

/************** End of mutex.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/


/*
** Each database file to be accessed by the system is an instance
** of the following structure.  There are normally two of these structures
** in the sqlite.aDb[] array.  aDb[0] is the main database file and
** aDb[1] is the database file used to hold temporary tables.  Additional
** databases may be attached.
*/
struct Db {
  char *zName;         /* Name of this database */
  Btree *pBt;          /* The B*Tree structure for this database file */
  u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
  u8 safety_level;     /* How aggressive at synching data to disk */
  void *pAux;               /* Auxiliary data.  Usually NULL */
  void (*xFreeAux)(void*);  /* Routine to free pAux */
  Schema *pSchema;     /* Pointer to database schema (possibly shared) */
};

/*
** An instance of the following structure stores a database schema.
**
** If there are no virtual tables configured in this schema, the
** Schema.db variable is set to NULL. After the first virtual table
** has been added, it is set to point to the database connection 
** used to create the connection. Once a virtual table has been
** added to the Schema structure and the Schema.db variable populated, 
** only that database connection may use the Schema to prepare 
** statements.
*/
struct Schema {
  int schema_cookie;   /* Database schema version number for this file */
  Hash tblHash;        /* All tables indexed by name */
  Hash idxHash;        /* All (named) indices indexed by name */
  Hash trigHash;       /* All triggers indexed by name */
  Hash aFKey;          /* Foreign keys indexed by to-table */
  Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
  u8 file_format;      /* Schema format version for this file */
  u8 enc;              /* Text encoding used by this database */
  u16 flags;           /* Flags associated with this schema */
  int cache_size;      /* Number of pages to use in the cache */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3 *db;         /* "Owner" connection. See comment above */
#endif
};

/*
** These macros can be used to test, set, or clear bits in the 
** Db.flags field.
*/
#define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
#define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
#define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
#define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)

/*
** Allowed values for the DB.flags field.
**
** The DB_SchemaLoaded flag is set after the database schema has been
** read into internal hash tables.
**
** DB_UnresetViews means that one or more views have column names that
** have been filled out.  If the schema changes, these column names might
** changes and so the view will need to be reset.
*/
#define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
#define DB_UnresetViews    0x0002  /* Some views have defined column names */
#define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */

/*
** The number of different kinds of things that can be limited
** using the sqlite3_limit() interface.
*/
#define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)

/*
** Each database is an instance of the following structure.
**
** The sqlite.lastRowid records the last insert rowid generated by an
** insert statement.  Inserts on views do not affect its value.  Each
** trigger has its own context, so that lastRowid can be updated inside
** triggers as usual.  The previous value will be restored once the trigger
** exits.  Upon entering a before or instead of trigger, lastRowid is no
** longer (since after version 2.8.12) reset to -1.
**
** The sqlite.nChange does not count changes within triggers and keeps no
** context.  It is reset at start of sqlite3_exec.
** The sqlite.lsChange represents the number of changes made by the last
** insert, update, or delete statement.  It remains constant throughout the
** length of a statement and is then updated by OP_SetCounts.  It keeps a
** context stack just like lastRowid so that the count of changes
** within a trigger is not seen outside the trigger.  Changes to views do not
** affect the value of lsChange.
** The sqlite.csChange keeps track of the number of current changes (since
** the last statement) and is used to update sqlite_lsChange.
**
** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
** store the most recent error code and, if applicable, string. The
** internal function sqlite3Error() is used to set these variables
** consistently.
*/
struct sqlite3 {
  sqlite3_vfs *pVfs;            /* OS Interface */
  int nDb;                      /* Number of backends currently in use */
  Db *aDb;                      /* All backends */
  int flags;                    /* Miscellanous flags. See below */
  int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errMask;                  /* & result codes with this before returning */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */
  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
  u8 dfltJournalMode;           /* Default journal mode for attached dbs */
  signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
  int nextPagesize;             /* Pagesize after VACUUM if >0 */
  int nTable;                   /* Number of tables in the database */
  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 priorNewRowid;            /* Last randomly generated ROWID */
  int magic;                    /* Magic number for detect library misuse */
  int nChange;                  /* Value returned by sqlite3_changes() */
  int nTotalChange;             /* Value returned by sqlite3_total_changes() */
  sqlite3_mutex *mutex;         /* Connection mutex */
  int aLimit[SQLITE_N_LIMIT];   /* Limits */
  struct sqlite3InitInfo {      /* Information used during initialization */
    int iDb;                    /* When back is being initialized */
    int newTnum;                /* Rootpage of table being initialized */
    u8 busy;                    /* TRUE if currently initializing */
  } init;
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared libraray handles */
  struct Vdbe *pVdbe;           /* List of active virtual machines */
  int activeVdbeCnt;            /* Number of vdbes currently executing */
  void (*xTrace)(void*,const char*);        /* Trace function */
  void *pTraceArg;                          /* Argument to the trace function */
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
  void *pUpdateArg;
  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
  void *pCollNeededArg;
  sqlite3_value *pErr;          /* Most recent error message */
  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
  union {
    int isInterrupted;          /* True if sqlite3_interrupt has been called */
    double notUsed1;            /* Spacer */
  } u1;
#ifndef SQLITE_OMIT_AUTHORIZATION
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
                                /* Access authorization function */
  void *pAuthArg;               /* 1st argument to the access auth function */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int (*xProgress)(void *);     /* The progress callback */
  void *pProgressArg;           /* Argument to the progress callback */
  int nProgressOps;             /* Number of opcodes for progress callback */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Hash aModule;                 /* populated by sqlite3_create_module() */
  Table *pVTab;                 /* vtab with active Connect/Create method */
  sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
  int nVTrans;                  /* Allocated size of aVTrans */
#endif
  Hash aFunc;                   /* All functions that can be in SQL exprs */
  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
#ifdef SQLITE_SSE
  sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
#endif
};

/*
** A macro to discover the encoding of a database.
*/
#define ENC(db) ((db)->aDb[0].pSchema->enc)

/*
** Possible values for the sqlite.flags and or Db.flags fields.
**
** On sqlite.flags, the SQLITE_InTrans value means that we have
** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
** transaction is active on that particular database file.
*/
#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
#define SQLITE_InTrans        0x00000008  /* True if in a transaction */
#define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                          /*   DELETE, or UPDATE and return */
                                          /*   the count using a callback. */
#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                          /*   result set is empty */
#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
#define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when 
                                          ** accessing read-only databases */
#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
#define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
#define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
#define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */

#define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
#define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
#define SQLITE_Vtab           0x00100000  /* There exists a virtual table */

/*
** Possible values for the sqlite.magic field.
** The numbers are obtained at random and have no special meaning, other
** than being distinct from one another.
*/
#define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
#define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
#define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
#define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
#define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */

/*
** Each SQL function is defined by an instance of the following
** structure.  A pointer to this structure is stored in the sqlite.aFunc
** hash table.  When multiple functions have the same name, the hash table
** points to a linked list of these structures.
*/
struct FuncDef {
  i16 nArg;            /* Number of arguments.  -1 means unlimited */
  u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
  u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
  u8 flags;            /* Some combination of SQLITE_FUNC_* */
  void *pUserData;     /* User data parameter */
  FuncDef *pNext;      /* Next function with same name */
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
  void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
  char zName[1];       /* SQL name of the function.  MUST BE LAST */
};

/*
** Each SQLite module (virtual table definition) is defined by an
** instance of the following structure, stored in the sqlite3.aModule
** hash table.
*/
struct Module {
  const sqlite3_module *pModule;       /* Callback pointers */
  const char *zName;                   /* Name passed to create_module() */
  void *pAux;                          /* pAux passed to create_module() */
  void (*xDestroy)(void *);            /* Module destructor function */
};

/*
** Possible values for FuncDef.flags
*/
#define SQLITE_FUNC_LIKE   0x01  /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE   0x02  /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM  0x04  /* Ephermeral.  Delete with VDBE */

/*
** information about each column of an SQL table is held in an instance
** of this structure.
*/
struct Column {
  char *zName;     /* Name of this column */
  Expr *pDflt;     /* Default value of this column */
  char *zType;     /* Data type for this column */
  char *zColl;     /* Collating sequence.  If NULL, use the default */
  u8 notNull;      /* True if there is a NOT NULL constraint */
  u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
  char affinity;   /* One of the SQLITE_AFF_... values */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u8 isHidden;     /* True if this column is 'hidden' */
#endif
};

/*
** A "Collating Sequence" is defined by an instance of the following
** structure. Conceptually, a collating sequence consists of a name and
** a comparison routine that defines the order of that sequence.
**
** There may two seperate implementations of the collation function, one
** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
** native byte order. When a collation sequence is invoked, SQLite selects
** the version that will require the least expensive encoding
** translations, if any.
**
** The CollSeq.pUser member variable is an extra parameter that passed in
** as the first argument to the UTF-8 comparison function, xCmp.
** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
** xCmp16.
**
** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
** collating sequence is undefined.  Indices built on an undefined
** collating sequence may not be read or written.
*/
struct CollSeq {
  char *zName;          /* Name of the collating sequence, UTF-8 encoded */
  u8 enc;               /* Text encoding handled by xCmp() */
  u8 type;              /* One of the SQLITE_COLL_... values below */
  void *pUser;          /* First argument to xCmp() */
  int (*xCmp)(void*,int, const void*, int, const void*);
  void (*xDel)(void*);  /* Destructor for pUser */
};

/*
** Allowed values of CollSeq flags:
*/
#define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
#define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
#define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
#define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */

/*
** A sort order can be either ASC or DESC.
*/
#define SQLITE_SO_ASC       0  /* Sort in ascending order */
#define SQLITE_SO_DESC      1  /* Sort in ascending order */

/*
** Column affinity types.
**
** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
** the speed a little by number the values consecutively.  
**
** But rather than start with 0 or 1, we begin with 'a'.  That way,
** when multiple affinity types are concatenated into a string and
** used as the P4 operand, they will be more readable.
**
** Note also that the numeric types are grouped together so that testing
** for a numeric type is a single comparison.
*/
#define SQLITE_AFF_TEXT     'a'
#define SQLITE_AFF_NONE     'b'
#define SQLITE_AFF_NUMERIC  'c'
#define SQLITE_AFF_INTEGER  'd'
#define SQLITE_AFF_REAL     'e'

#define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)

/*
** The SQLITE_AFF_MASK values masks off the significant bits of an
** affinity value. 
*/
#define SQLITE_AFF_MASK     0x67

/*
** Additional bit values that can be ORed with an affinity without
** changing the affinity.
*/
#define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
#define SQLITE_NULLEQUAL    0x10  /* compare NULLs equal */
#define SQLITE_STOREP2      0x80  /* Store result in reg[P2] rather than jump */

/*
** Each SQL table is represented in memory by an instance of the
** following structure.
**
** Table.zName is the name of the table.  The case of the original
** CREATE TABLE statement is stored, but case is not significant for
** comparisons.
**
** Table.nCol is the number of columns in this table.  Table.aCol is a
** pointer to an array of Column structures, one for each column.
**
** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
** the column that is that key.   Otherwise Table.iPKey is negative.  Note
** that the datatype of the PRIMARY KEY must be INTEGER for this field to
** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
** is generated for each row of the table.  Table.hasPrimKey is true if
** the table has any PRIMARY KEY, INTEGER or otherwise.
**
** Table.tnum is the page number for the root BTree page of the table in the
** database file.  If Table.iDb is the index of the database table backend
** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
** holds temporary tables and indices.  If Table.isEphem
** is true, then the table is stored in a file that is automatically deleted
** when the VDBE cursor to the table is closed.  In this case Table.tnum 
** refers VDBE cursor number that holds the table open, not to the root
** page number.  Transient tables are used to hold the results of a
** sub-query that appears instead of a real table name in the FROM clause 
** of a SELECT statement.
*/
struct Table {
  char *zName;     /* Name of the table */
  int nCol;        /* Number of columns in this table */
  Column *aCol;    /* Information about each column */
  int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
  Index *pIndex;   /* List of SQL indexes on this table. */
  int tnum;        /* Root BTree node for this table (see note above) */
  Select *pSelect; /* NULL for tables.  Points to definition if a view. */
  int nRef;          /* Number of pointers to this Table */
  Trigger *pTrigger; /* List of SQL triggers on this table */
  FKey *pFKey;       /* Linked list of all foreign keys in this table */
  char *zColAff;     /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
  Expr *pCheck;      /* The AND of all CHECK constraints */
#endif
#ifndef SQLITE_OMIT_ALTERTABLE
  int addColOffset;  /* Offset in CREATE TABLE statement to add a new column */
#endif
  u8 readOnly;     /* True if this table should not be written by the user */
  u8 isEphem;      /* True if created using OP_OpenEphermeral */
  u8 hasPrimKey;   /* True if there exists a primary key */
  u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
  u8 autoInc;      /* True if the integer primary key is autoincrement */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u8 isVirtual;             /* True if this is a virtual table */
  u8 isCommit;              /* True once the CREATE TABLE has been committed */
  Module *pMod;             /* Pointer to the implementation of the module */
  sqlite3_vtab *pVtab;      /* Pointer to the module instance */
  int nModuleArg;           /* Number of arguments to the module */
  char **azModuleArg;       /* Text of all module args. [0] is module name */
#endif
  Schema *pSchema;          /* Schema that contains this table */
};

/*
** Test to see whether or not a table is a virtual table.  This is
** done as a macro so that it will be optimized out when virtual
** table support is omitted from the build.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#  define IsVirtual(X)      ((X)->isVirtual)
#  define IsHiddenColumn(X) ((X)->isHidden)
#else
#  define IsVirtual(X)      0
#  define IsHiddenColumn(X) 0
#endif

/*
** Each foreign key constraint is an instance of the following structure.
**
** A foreign key is associated with two tables.  The "from" table is
** the table that contains the REFERENCES clause that creates the foreign
** key.  The "to" table is the table that is named in the REFERENCES clause.
** Consider this example:
**
**     CREATE TABLE ex1(
**       a INTEGER PRIMARY KEY,
**       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
**     );
**
** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
**
** Each REFERENCES clause generates an instance of the following structure
** which is attached to the from-table.  The to-table need not exist when
** the from-table is created.  The existance of the to-table is not checked
** until an attempt is made to insert data into the from-table.
**
** The sqlite.aFKey hash table stores pointers to this structure
** given the name of a to-table.  For each to-table, all foreign keys
** associated with that table are on a linked list using the FKey.pNextTo
** field.
*/
struct FKey {
  Table *pFrom;     /* The table that constains the REFERENCES clause */
  FKey *pNextFrom;  /* Next foreign key in pFrom */
  char *zTo;        /* Name of table that the key points to */
  FKey *pNextTo;    /* Next foreign key that points to zTo */
  int nCol;         /* Number of columns in this key */
  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
    int iFrom;         /* Index of column in pFrom */
    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
  } *aCol;          /* One entry for each of nCol column s */
  u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
  u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
  u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
  u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
};

/*
** SQLite supports many different ways to resolve a constraint
** error.  ROLLBACK processing means that a constraint violation
** causes the operation in process to fail and for the current transaction
** to be rolled back.  ABORT processing means the operation in process
** fails and any prior changes from that one operation are backed out,
** but the transaction is not rolled back.  FAIL processing means that
** the operation in progress stops and returns an error code.  But prior
** changes due to the same operation are not backed out and no rollback
** occurs.  IGNORE means that the particular row that caused the constraint
** error is not inserted or updated.  Processing continues and no error
** is returned.  REPLACE means that preexisting database rows that caused
** a UNIQUE constraint violation are removed so that the new insert or
** update can proceed.  Processing continues and no error is reported.
**
** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
** referenced table row is propagated into the row that holds the
** foreign key.
** 
** The following symbolic values are used to record which type
** of action to take.
*/
#define OE_None     0   /* There is no constraint to check */
#define OE_Rollback 1   /* Fail the operation and rollback the transaction */
#define OE_Abort    2   /* Back out changes but do no rollback transaction */
#define OE_Fail     3   /* Stop the operation but leave all prior changes */
#define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
#define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */

#define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
#define OE_SetNull  7   /* Set the foreign key value to NULL */
#define OE_SetDflt  8   /* Set the foreign key value to its default */
#define OE_Cascade  9   /* Cascade the changes */

#define OE_Default  99  /* Do whatever the default action is */


/*
** An instance of the following structure is passed as the first
** argument to sqlite3VdbeKeyCompare and is used to control the 
** comparison of the two index keys.
**
** If the KeyInfo.incrKey value is true and the comparison would
** otherwise be equal, then return a result as if the second key
** were larger.
*/
struct KeyInfo {
  sqlite3 *db;        /* The database connection */
  u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
  u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
  u8 prefixIsEqual;   /* Treat a prefix as equal */
  int nField;         /* Number of entries in aColl[] */
  u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
};

/*
** Each SQL index is represented in memory by an
** instance of the following structure.
**
** The columns of the table that are to be indexed are described
** by the aiColumn[] field of this structure.  For example, suppose
** we have the following table and index:
**
**     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
**     CREATE INDEX Ex2 ON Ex1(c3,c1);
**
** In the Table structure describing Ex1, nCol==3 because there are
** three columns in the table.  In the Index structure describing
** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the 
** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
** The second column to be indexed (c1) has an index of 0 in
** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
**
** The Index.onError field determines whether or not the indexed columns
** must be unique and what to do if they are not.  When Index.onError=OE_None,
** it means this is not a unique index.  Otherwise it is a unique index
** and the value of Index.onError indicate the which conflict resolution 
** algorithm to employ whenever an attempt is made to insert a non-unique
** element.
*/
struct Index {
  char *zName;     /* Name of this index */
  int nColumn;     /* Number of columns in the table used by this index */
  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
  unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
  Table *pTable;   /* The SQL table being indexed */
  int tnum;        /* Page containing root of this index in database file */
  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */
};

/*
** Each token coming out of the lexer is an instance of
** this structure.  Tokens are also used as part of an expression.
**
** Note if Token.z==0 then Token.dyn and Token.n are undefined and
** may contain random values.  Do not make any assuptions about Token.dyn
** and Token.n when Token.z==0.
*/
struct Token {
  const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
  unsigned dyn  : 1;      /* True for malloced memory, false for static */
  unsigned n    : 31;     /* Number of characters in this token */
};

/*
** An instance of this structure contains information needed to generate
** code for a SELECT that contains aggregate functions.
**
** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
** pointer to this structure.  The Expr.iColumn field is the index in
** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
** code for that node.
**
** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
** original Select structure that describes the SELECT statement.  These
** fields do not need to be freed when deallocating the AggInfo structure.
*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** than the source table */
  int sortingIdx;         /* Cursor number of the sorting index */
  ExprList *pGroupBy;     /* The group by clause */
  int nSortingColumn;     /* Number of columns in the sorting index */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */
    int iMem;                /* Memory location that acts as accumulator */
    Expr *pExpr;             /* The original expression */
  } *aCol;
  int nColumn;            /* Number of used entries in aCol[] */
  int nColumnAlloc;       /* Number of slots allocated for aCol[] */
  int nAccumulator;       /* Number of columns that show through to the output.
                          ** Additional columns are used only as parameters to
                          ** aggregate functions */
  struct AggInfo_func {   /* For each aggregate function */
    Expr *pExpr;             /* Expression encoding the function */
    FuncDef *pFunc;          /* The aggregate function implementation */
    int iMem;                /* Memory location that acts as accumulator */
    int iDistinct;           /* Ephermeral table used to enforce DISTINCT */
  } *aFunc;
  int nFunc;              /* Number of entries in aFunc[] */
  int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
};

/*
** Each node of an expression in the parse tree is an instance
** of this structure.
**
** Expr.op is the opcode.  The integer parser token codes are reused
** as opcodes here.  For example, the parser defines TK_GE to be an integer
** code representing the ">=" operator.  This same integer code is reused
** to represent the greater-than-or-equal-to operator in the expression
** tree.
**
** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
** of argument if the expression is a function.
**
** Expr.token is the operator token for this node.  For some expressions
** that have subexpressions, Expr.token can be the complete text that gave
** rise to the Expr.  In the latter case, the token is marked as being
** a compound token.
**
** An expression of the form ID or ID.ID refers to a column in a table.
** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
** the integer cursor number of a VDBE cursor pointing to that table and
** Expr.iColumn is the column number for the specific column.  If the
** expression is used as a result in an aggregate SELECT, then the
** value is also stored in the Expr.iAgg column in the aggregate so that
** it can be accessed after all aggregates are computed.
**
** If the expression is a function, the Expr.iTable is an integer code
** representing which function.  If the expression is an unbound variable
** marker (a question mark character '?' in the original SQL) then the
** Expr.iTable holds the index number for that variable.
**
** If the expression is a subquery then Expr.iColumn holds an integer
** register number containing the result of the subquery.  If the
** subquery gives a constant result, then iTable is -1.  If the subquery
** gives a different answer at different times during statement processing
** then iTable is the address of a subroutine that computes the subquery.
**
** The Expr.pSelect field points to a SELECT statement.  The SELECT might
** be the right operand of an IN operator.  Or, if a scalar SELECT appears
** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
** operand.
**
** If the Expr is of type OP_Column, and the table it is selecting from
** is a disk table or the "old.*" pseudo-table, then pTab points to the
** corresponding table definition.
*/
struct Expr {
  u8 op;                 /* Operation performed by this node */
  char affinity;         /* The affinity of the column or 0 if not a column */
  u16 flags;             /* Various flags.  See below */
  CollSeq *pColl;        /* The collation type of the column or 0 */
  Expr *pLeft, *pRight;  /* Left and right subnodes */
  ExprList *pList;       /* A list of expressions used as function arguments
                         ** or in "<expr> IN (<expr-list)" */
  Token token;           /* An operand token */
  Token span;            /* Complete text of the expression */
  int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
                         ** iColumn-th field of the iTable-th table. */
  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  Select *pSelect;       /* When the expression is a sub-select.  Also the
                         ** right side of "<expr> IN (<select>)" */
  Table *pTab;           /* Table for OP_Column expressions. */
/*  Schema *pSchema; */
#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
};

/*
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
#define EP_Agg        0x0002  /* Contains one or more aggregate functions */
#define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
#define EP_Error      0x0008  /* Expression contains one or more errors */
#define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
#define EP_Dequoted   0x0040  /* True if the string has been dequoted */
#define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
#define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
#define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
#define EP_FixedDest  0x0400  /* Result needed in a specific register */

/*
** These macros can be used to test, set, or clear bits in the 
** Expr.flags field.
*/
#define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
#define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
#define ExprSetProperty(E,P)     (E)->flags|=(P)
#define ExprClearProperty(E,P)   (E)->flags&=~(P)

/*
** A list of expressions.  Each expression may optionally have a
** name.  An expr/name combination can be used in several ways, such
** as the list of "expr AS ID" fields following a "SELECT" or in the
** list of "ID = expr" items in an UPDATE.  A list of expressions can
** also be used as the argument to a function, in which case the a.zName
** field is not used.
*/
struct ExprList {
  int nExpr;             /* Number of expressions on the list */
  int nAlloc;            /* Number of entries allocated below */
  int iECursor;          /* VDBE Cursor associated with this ExprList */
  struct ExprList_item {
    Expr *pExpr;           /* The list of expressions */
    char *zName;           /* Token associated with this expression */
    u8 sortOrder;          /* 1 for DESC or 0 for ASC */
    u8 isAgg;              /* True if this is an aggregate like count(*) */
    u8 done;               /* A flag to indicate when processing is finished */
  } *a;                  /* One entry for each expression */
};

/*
** An instance of this structure can hold a simple list of identifiers,
** such as the list "a,b,c" in the following statements:
**
**      INSERT INTO t(a,b,c) VALUES ...;
**      CREATE INDEX idx ON t(a,b,c);
**      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
**
** The IdList.a.idx field is used when the IdList represents the list of
** column names after a table name in an INSERT statement.  In the statement
**
**     INSERT INTO t(a,b,c) ...
**
** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
*/
struct IdList {
  struct IdList_item {
    char *zName;      /* Name of the identifier */
    int idx;          /* Index in some Table.aCol[] of a column named zName */
  } *a;
  int nId;         /* Number of identifiers on the list */
  int nAlloc;      /* Number of entries allocated for a[] below */
};

/*
** The bitmask datatype defined below is used for various optimizations.
**
** Changing this from a 64-bit to a 32-bit type limits the number of
** tables in a join to 32 instead of 64.  But it also reduces the size
** of the library by 738 bytes on ix86.
*/
typedef u64 Bitmask;

/*
** The following structure describes the FROM clause of a SELECT statement.
** Each table or subquery in the FROM clause is a separate element of
** the SrcList.a[] array.
**
** With the addition of multiple database support, the following structure
** can also be used to describe a particular table such as the table that
** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
** such a table must be a simple name: ID.  But in SQLite, the table can
** now be identified by a database name, a dot, then the table name: ID.ID.
**
** The jointype starts out showing the join type between the current table
** and the next table on the list.  The parser builds the list this way.
** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
** jointype expresses the join between the table and the previous table.
*/
struct SrcList {
  i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
  i16 nAlloc;      /* Number of entries allocated in a[] below */
  struct SrcList_item {
    char *zDatabase;  /* Name of database holding this table */
    char *zName;      /* Name of the table */
    char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
    Table *pTab;      /* An SQL table corresponding to zName */
    Select *pSelect;  /* A SELECT statement used in place of a table name */
    u8 isPopulated;   /* Temporary table associated with SELECT is populated */
    u8 jointype;      /* Type of join between this able and the previous */
    int iCursor;      /* The VDBE cursor number used to access this table */
    Expr *pOn;        /* The ON clause of a join */
    IdList *pUsing;   /* The USING clause of a join */
    Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
  } a[1];             /* One entry for each identifier on the list */
};

/*
** Permitted values of the SrcList.a.jointype field
*/
#define JT_INNER     0x0001    /* Any kind of inner or cross join */
#define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
#define JT_NATURAL   0x0004    /* True for a "natural" join */
#define JT_LEFT      0x0008    /* Left outer join */
#define JT_RIGHT     0x0010    /* Right outer join */
#define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
#define JT_ERROR     0x0040    /* unknown or unsupported join type */

/*
** For each nested loop in a WHERE clause implementation, the WhereInfo
** structure contains a single instance of this structure.  This structure
** is intended to be private the the where.c module and should not be
** access or modified by other modules.
**
** The pIdxInfo and pBestIdx fields are used to help pick the best
** index on a virtual table.  The pIdxInfo pointer contains indexing
** information for the i-th table in the FROM clause before reordering.
** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
** FROM clause ordering.  This is a little confusing so I will repeat
** it in different words.  WhereInfo.a[i].pIdxInfo is index information 
** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
** index information for the i-th loop of the join.  pBestInfo is always
** either NULL or a copy of some pIdxInfo.  So for cleanup it is 
** sufficient to free all of the pIdxInfo pointers.
** 
*/
struct WhereLevel {
  int iFrom;            /* Which entry in the FROM clause */
  int flags;            /* Flags associated with this level */
  int iMem;             /* First memory cell used by this level */
  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
  Index *pIdx;          /* Index used.  NULL if no index */
  int iTabCur;          /* The VDBE cursor used to access the table */
  int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
  int brk;              /* Jump here to break out of the loop */
  int nxt;              /* Jump here to start the next IN combination */
  int cont;             /* Jump here to continue with the next loop cycle */
  int top;              /* First instruction of interior of the loop */
  int op, p1, p2;       /* Opcode used to terminate the loop */
  int nEq;              /* Number of == or IN constraints on this loop */
  int nIn;              /* Number of IN operators constraining this loop */
  struct InLoop {
    int iCur;              /* The VDBE cursor used by this IN operator */
    int topAddr;           /* Top of the IN loop */
  } *aInLoop;           /* Information about each nested IN operator */
  sqlite3_index_info *pBestIdx;  /* Index information for this level */

  /* The following field is really not part of the current level.  But
  ** we need a place to cache index information for each table in the
  ** FROM clause and the WhereLevel structure is a convenient place.
  */
  sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
};

/*
** Flags appropriate for the wflags parameter of sqlite3WhereBegin().
*/
#define WHERE_ORDERBY_NORMAL     0   /* No-op */
#define WHERE_ORDERBY_MIN        1   /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX        2   /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED    4   /* Want to do one-pass UPDATE/DELETE */

/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
struct WhereInfo {
  Parse *pParse;       /* Parsing and code generating context */
  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
  SrcList *pTabList;   /* List of tables in the join */
  int iTop;            /* The very beginning of the WHERE loop */
  int iContinue;       /* Jump here to continue with next record */
  int iBreak;          /* Jump here to break out of the loop */
  int nLevel;          /* Number of nested loop */
  sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
  WhereLevel a[1];     /* Information about each nest loop in the WHERE */
};

/*
** A NameContext defines a context in which to resolve table and column
** names.  The context consists of a list of tables (the pSrcList) field and
** a list of named expression (pEList).  The named expression list may
** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
** to the table being operated on by INSERT, UPDATE, or DELETE.  The
** pEList corresponds to the result set of a SELECT and is NULL for
** other statements.
**
** NameContexts can be nested.  When resolving names, the inner-most 
** context is searched first.  If no match is found, the next outer
** context is checked.  If there is still no match, the next context
** is checked.  This process continues until either a match is found
** or all contexts are check.  When a match is found, the nRef member of
** the context containing the match is incremented. 
**
** Each subquery gets a new NameContext.  The pNext field points to the
** NameContext in the parent query.  Thus the process of scanning the
** NameContext list corresponds to searching through successively outer
** subqueries looking for a match.
*/
struct NameContext {
  Parse *pParse;       /* The parser */
  SrcList *pSrcList;   /* One or more tables used to resolve names */
  ExprList *pEList;    /* Optional list of named expressions */
  int nRef;            /* Number of names resolved by this context */
  int nErr;            /* Number of errors encountered while resolving names */
  u8 allowAgg;         /* Aggregate functions allowed here */
  u8 hasAgg;           /* True if aggregates are seen */
  u8 isCheck;          /* True if resolving names in a CHECK constraint */
  int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
  AggInfo *pAggInfo;   /* Information about aggregates at this level */
  NameContext *pNext;  /* Next outer name context.  NULL for outermost */
};

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
** If there is a LIMIT clause, the parser sets nLimit to the value of the
** limit and nOffset to the value of the offset (or 0 if there is not
** offset).  But later on, nLimit and nOffset become the memory locations
** in the VDBE that record the limit and offset counters.
**
** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
** These addresses must be stored so that we can go back and fill in
** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
** the number of columns in P2 can be computed at the same time
** as the OP_OpenEphm instruction is coded because not
** enough information about the compound query is known at that point.
** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
** sequences for the ORDER BY clause.
*/
struct Select {
  ExprList *pEList;      /* The fields of the result */
  u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
  u8 isDistinct;         /* True if the DISTINCT keyword is present */
  u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
  u8 isAgg;              /* True if this is an aggregate query */
  u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
  u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
  char affinity;         /* MakeRecord with this affinity for SRT_Set */
  SrcList *pSrc;         /* The FROM clause */
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  Select *pPrior;        /* Prior select in a compound select statement */
  Select *pNext;         /* Next select to the left in a compound */
  Select *pRightmost;    /* Right-most select in a compound select statement */
  Expr *pLimit;          /* LIMIT expression. NULL means not used. */
  Expr *pOffset;         /* OFFSET expression. NULL means not used. */
  int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
  int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
};

/*
** The results of a select can be distributed in several ways.
*/
#define SRT_Union        1  /* Store result as keys in an index */
#define SRT_Except       2  /* Remove result from a UNION index */
#define SRT_Exists       3  /* Store 1 if the result is not empty */
#define SRT_Discard      4  /* Do not save the results anywhere */

/* The ORDER BY clause is ignored for all of the above */
#define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)

#define SRT_Callback     5  /* Invoke a callback with each row of result */
#define SRT_Mem          6  /* Store result in a memory cell */
#define SRT_Set          7  /* Store non-null results as keys in an index */
#define SRT_Table        8  /* Store result as data with an automatic rowid */
#define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
#define SRT_Subroutine  10  /* Call a subroutine to handle results */

/*
** A structure used to customize the behaviour of sqlite3Select(). See
** comments above sqlite3Select() for details.
*/
typedef struct SelectDest SelectDest;
struct SelectDest {
  u8 eDest;         /* How to dispose of the results */
  u8 affinity;      /* Affinity used when eDest==SRT_Set */
  int iParm;        /* A parameter used by the eDest disposal method */
  int iMem;         /* Base register where results are written */
  int nMem;         /* Number of registers allocated */
};

/*
** An SQL parser context.  A copy of this structure is passed through
** the parser and down into all the parser action routine in order to
** carry around information that is global to the entire parse.
**
** The structure is divided into two parts.  When the parser and code
** generate call themselves recursively, the first part of the structure
** is constant but the second part is reset at the beginning and end of
** each recursion.
**
** The nTableLock and aTableLock variables are only used if the shared-cache 
** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
** used to store the set of table-locks required by the statement being
** compiled. Function sqlite3TableLock() is used to add entries to the
** list.
*/
struct Parse {
  sqlite3 *db;         /* The main database structure */
  int rc;              /* Return code from execution */
  char *zErrMsg;       /* An error message */
  Vdbe *pVdbe;         /* An engine for executing database bytecode */
  u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
  u8 nameClash;        /* A permanent table name clashes with temp table name */
  u8 checkSchema;      /* Causes schema cookie check after an error */
  u8 nested;           /* Number of nested calls to the parser/code generator */
  u8 parseError;       /* True after a parsing error.  Ticket #1794 */
  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
  u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
  int aTempReg[8];     /* Holding area for temporary registers */
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nSet;            /* Number of sets used so far */
  int ckBase;          /* Base register of data during check constraints */
  int disableColCache; /* True to disable adding to column cache */
  int nColCache;       /* Number of entries in the column cache */
  int iColCache;       /* Next entry of the cache to replace */
  struct yColCache {
    int iTable;           /* Table cursor number */
    int iColumn;          /* Table column number */
    char affChange;       /* True if this register has had an affinity change */
    int iReg;             /* Register holding value of this column */
  } aColCache[10];     /* One for each valid column cache entry */
  u32 writeMask;       /* Start a write transaction on these databases */
  u32 cookieMask;      /* Bitmask of schema verified databases */
  int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
  int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nTableLock;        /* Number of locks in aTableLock */
  TableLock *aTableLock; /* Required table locks for shared-cache mode */
#endif
  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
  int regRoot;         /* Register holding root page number for new objects */

  /* Above is constant between recursions.  Below is reset before and after
  ** each recursion */

  int nVar;            /* Number of '?' variables seen in the SQL so far */
  int nVarExpr;        /* Number of used slots in apVarExpr[] */
  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
  Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
  u8 explain;          /* True if the EXPLAIN flag is found on the query */
  Token sErrToken;     /* The token at which the error occurred */
  Token sNameToken;    /* Token with unqualified schema object name */
  Token sLastToken;    /* The last token parsed */
  const char *zSql;    /* All SQL text */
  const char *zTail;   /* All SQL text past the last semicolon parsed */
  Table *pNewTable;    /* A table being constructed by CREATE TABLE */
  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
  TriggerStack *trigStack;  /* Trigger actions being coded */
  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Token sArg;                /* Complete text of a module argument */
  u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
  int nVtabLock;             /* Number of virtual tables to lock */
  Table **apVtabLock;        /* Pointer to virtual tables needing locking */
#endif
#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;            /* Expression tree height of current sub-select */
#endif
};

#ifdef SQLITE_OMIT_VIRTUALTABLE
  #define IN_DECLARE_VTAB 0
#else
  #define IN_DECLARE_VTAB (pParse->declareVtab)
#endif

/*
** An instance of the following structure can be declared on a stack and used
** to save the Parse.zAuthContext value so that it can be restored later.
*/
struct AuthContext {
  const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
  Parse *pParse;              /* The Parse structure */
};

/*
** Bitfield flags for P2 value in OP_Insert and OP_Delete
*/
#define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
#define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
#define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
#define OPFLAG_APPEND    8    /* This is likely to be an append */

/*
 * Each trigger present in the database schema is stored as an instance of
 * struct Trigger. 
 *
 * Pointers to instances of struct Trigger are stored in two ways.
 * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
 *    database). This allows Trigger structures to be retrieved by name.
 * 2. All triggers associated with a single table form a linked list, using the
 *    pNext member of struct Trigger. A pointer to the first element of the
 *    linked list is stored as the "pTrigger" member of the associated
 *    struct Table.
 *
 * The "step_list" member points to the first element of a linked list
 * containing the SQL statements specified as the trigger program.
 */
struct Trigger {
  char *name;             /* The name of the trigger                        */
  char *table;            /* The table or view to which the trigger applies */
  u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
  u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
  Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
  IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
                             the <column-list> is stored here */
  Token nameToken;        /* Token containing zName. Use during parsing only */
  Schema *pSchema;        /* Schema containing the trigger */
  Schema *pTabSchema;     /* Schema containing the table */
  TriggerStep *step_list; /* Link list of trigger program steps             */
  Trigger *pNext;         /* Next trigger associated with the table */
};

/*
** A trigger is either a BEFORE or an AFTER trigger.  The following constants
** determine which. 
**
** If there are multiple triggers, you might of some BEFORE and some AFTER.
** In that cases, the constants below can be ORed together.
*/
#define TRIGGER_BEFORE  1
#define TRIGGER_AFTER   2

/*
 * An instance of struct TriggerStep is used to store a single SQL statement
 * that is a part of a trigger-program. 
 *
 * Instances of struct TriggerStep are stored in a singly linked list (linked
 * using the "pNext" member) referenced by the "step_list" member of the 
 * associated struct Trigger instance. The first element of the linked list is
 * the first step of the trigger-program.
 * 
 * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
 * "SELECT" statement. The meanings of the other members is determined by the 
 * value of "op" as follows:
 *
 * (op == TK_INSERT)
 * orconf    -> stores the ON CONFLICT algorithm
 * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
 *              this stores a pointer to the SELECT statement. Otherwise NULL.
 * target    -> A token holding the name of the table to insert into.
 * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
 *              this stores values to be inserted. Otherwise NULL.
 * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ... 
 *              statement, then this stores the column-names to be
 *              inserted into.
 *
 * (op == TK_DELETE)
 * target    -> A token holding the name of the table to delete from.
 * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
 *              Otherwise NULL.
 * 
 * (op == TK_UPDATE)
 * target    -> A token holding the name of the table to update rows of.
 * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
 *              Otherwise NULL.
 * pExprList -> A list of the columns to update and the expressions to update
 *              them to. See sqlite3Update() documentation of "pChanges"
 *              argument.
 * 
 */
struct TriggerStep {
  int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
  int orconf;          /* OE_Rollback etc. */
  Trigger *pTrig;      /* The trigger that this step is a part of */

  Select *pSelect;     /* Valid for SELECT and sometimes 
                          INSERT steps (when pExprList == 0) */
  Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
  Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
  ExprList *pExprList; /* Valid for UPDATE statements and sometimes 
                           INSERT steps (when pSelect == 0)         */
  IdList *pIdList;     /* Valid for INSERT statements only */
  TriggerStep *pNext;  /* Next in the link-list */
  TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
};

/*
 * An instance of struct TriggerStack stores information required during code
 * generation of a single trigger program. While the trigger program is being
 * coded, its associated TriggerStack instance is pointed to by the
 * "pTriggerStack" member of the Parse structure.
 *
 * The pTab member points to the table that triggers are being coded on. The 
 * newIdx member contains the index of the vdbe cursor that points at the temp
 * table that stores the new.* references. If new.* references are not valid
 * for the trigger being coded (for example an ON DELETE trigger), then newIdx
 * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
 *
 * The ON CONFLICT policy to be used for the trigger program steps is stored 
 * as the orconf member. If this is OE_Default, then the ON CONFLICT clause 
 * specified for individual triggers steps is used.
 *
 * struct TriggerStack has a "pNext" member, to allow linked lists to be
 * constructed. When coding nested triggers (triggers fired by other triggers)
 * each nested trigger stores its parent trigger's TriggerStack as the "pNext" 
 * pointer. Once the nested trigger has been coded, the pNext value is restored
 * to the pTriggerStack member of the Parse stucture and coding of the parent
 * trigger continues.
 *
 * Before a nested trigger is coded, the linked list pointed to by the 
 * pTriggerStack is scanned to ensure that the trigger is not about to be coded
 * recursively. If this condition is detected, the nested trigger is not coded.
 */
struct TriggerStack {
  Table *pTab;         /* Table that triggers are currently being coded on */
  int newIdx;          /* Index of vdbe cursor to "new" temp table */
  int oldIdx;          /* Index of vdbe cursor to "old" temp table */
  u32 newColMask;
  u32 oldColMask;
  int orconf;          /* Current orconf policy */
  int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
  Trigger *pTrigger;   /* The trigger currently being coded */
  TriggerStack *pNext; /* Next trigger down on the trigger stack */
};

/*
** The following structure contains information used by the sqliteFix...
** routines as they walk the parse tree to make database references
** explicit.  
*/
typedef struct DbFixer DbFixer;
struct DbFixer {
  Parse *pParse;      /* The parsing context.  Error messages written here */
  const char *zDb;    /* Make sure all objects are contained in this database */
  const char *zType;  /* Type of the container - used for error messages */
  const Token *pName; /* Name of the container - used for error messages */
};

/*
** An objected used to accumulate the text of a string where we
** do not necessarily know how big the string will be in the end.
*/
struct StrAccum {
  char *zBase;     /* A base allocation.  Not from malloc. */
  char *zText;     /* The string collected so far */
  int  nChar;      /* Length of the string so far */
  int  nAlloc;     /* Amount of space allocated in zText */
  int  mxAlloc;        /* Maximum allowed string length */
  u8   mallocFailed;   /* Becomes true if any memory allocation fails */
  u8   useMalloc;      /* True if zText is enlargable using realloc */
  u8   tooBig;         /* Becomes true if string size exceeds limits */
};

/*
** A pointer to this structure is used to communicate information
** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
*/
typedef struct {
  sqlite3 *db;        /* The database being initialized */
  int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
  char **pzErrMsg;    /* Error message stored here */
  int rc;             /* Result code stored here */
} InitData;

/*
** Assuming zIn points to the first byte of a UTF-8 character,
** advance zIn to point to the first byte of the next UTF-8 character.
*/
#define SQLITE_SKIP_UTF8(zIn) {                        \
  if( (*(zIn++))>=0xc0 ){                              \
    while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
  }                                                    \
}

/*
** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
** builds) or a function call (for debugging).  If it is a function call,
** it allows the operator to set a breakpoint at the spot where database
** corruption is first detected.
*/
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   int sqlite3Corrupt(void);
# define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
# define DEBUGONLY(X)        X
#else
# define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
# define DEBUGONLY(X)
#endif

/*
** Internal function prototypes
*/
SQLITE_PRIVATE int sqlite3StrICmp(const char *, const char *);
SQLITE_PRIVATE int sqlite3StrNICmp(const char *, const char *, int);
SQLITE_PRIVATE int sqlite3IsNumber(const char*, int*, u8);

SQLITE_PRIVATE void *sqlite3MallocZero(unsigned);
SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, unsigned);
SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, unsigned);
SQLITE_PRIVATE char *sqlite3StrDup(const char*);
SQLITE_PRIVATE char *sqlite3StrNDup(const char*, int);
SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3*,const char*);
SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, int);
SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, int);
SQLITE_PRIVATE int sqlite3MallocSize(void *);

SQLITE_PRIVATE int sqlite3IsNaN(double);

SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3*,const char*, ...);
SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
SQLITE_PRIVATE   void sqlite3DebugPrintf(const char*, ...);
#endif
#if defined(SQLITE_TEST)
SQLITE_PRIVATE   void *sqlite3TextToPtr(const char*);
#endif
SQLITE_PRIVATE void sqlite3SetString(char **, ...);
SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3ErrorClear(Parse*);
SQLITE_PRIVATE void sqlite3Dequote(char*);
SQLITE_PRIVATE void sqlite3DequoteExpr(sqlite3*, Expr*);
SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);
SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, char **);
SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);
SQLITE_PRIVATE int sqlite3GetTempReg(Parse*);
SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);
SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);
SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);
SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
SQLITE_PRIVATE Expr *sqlite3RegisterExpr(Parse*,Token*);
SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
SQLITE_PRIVATE void sqlite3ExprSpan(Expr*,Token*,Token*);
SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3ExprDelete(Expr*);
SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
SQLITE_PRIVATE void sqlite3ExprListDelete(ExprList*);
SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3*, int);
SQLITE_PRIVATE void sqlite3BeginParse(Parse*,int);
SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);
SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *, int);
SQLITE_PRIVATE void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*);
SQLITE_PRIVATE void sqlite3AddNotNull(Parse*, int);
SQLITE_PRIVATE void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
SQLITE_PRIVATE void sqlite3AddCheckConstraint(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3AddColumnType(Parse*,Token*);
SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse*,Expr*);
SQLITE_PRIVATE void sqlite3AddCollateType(Parse*, Token*);
SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,Select*);

SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32);
SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec*, u32);
SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec*, u32);
SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec*, u32);
SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec*);
SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int,int*);

SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);

#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
#else
# define sqlite3ViewGetColumnNames(A,B) 0
#endif

SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);
SQLITE_PRIVATE void sqlite3DeleteTable(Table*);
SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
SQLITE_PRIVATE IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
SQLITE_PRIVATE int sqlite3IdListIndex(IdList*,const char*);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, Token*,
                                      Select*, Expr*, IdList*);
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);
SQLITE_PRIVATE void sqlite3IdListDelete(IdList*);
SQLITE_PRIVATE void sqlite3SrcListDelete(SrcList*);
SQLITE_PRIVATE void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                        Token*, int, int);
SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);
SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*, Select*, int, int*, char *aff);
SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,int,Expr*,Expr*);
SQLITE_PRIVATE void sqlite3SelectDelete(Select*);
SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);
SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, int);
SQLITE_PRIVATE void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);
SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse*, int, int);
SQLITE_PRIVATE void sqlite3ExprClearColumnCache(Parse*, int);
SQLITE_PRIVATE void sqlite3ExprCacheAffinityChange(Parse*, int, int);
SQLITE_PRIVATE int sqlite3ExprWritableRegister(Parse*,int,int);
SQLITE_PRIVATE void sqlite3ExprHardCopy(Parse*,int,int);
SQLITE_PRIVATE int sqlite3ExprCode(Parse*, Expr*, int);
SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse*, Expr*, int);
SQLITE_PRIVATE int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
SQLITE_PRIVATE void sqlite3ExprCodeConstants(Parse*, Expr*);
SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3*,const char*, const char*);
SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
SQLITE_PRIVATE void sqlite3Vacuum(Parse*);
SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*);
SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3ExprCompare(Expr*, Expr*);
SQLITE_PRIVATE int sqlite3ExprResolveNames(NameContext *, Expr *);
SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
SQLITE_PRIVATE void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse*);
SQLITE_PRIVATE Expr *sqlite3CreateIdExpr(Parse *, const char*);
SQLITE_PRIVATE void sqlite3PrngSaveState(void);
SQLITE_PRIVATE void sqlite3PrngRestoreState(void);
SQLITE_PRIVATE void sqlite3PrngResetState(void);
SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3*);
SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse*, int);
SQLITE_PRIVATE void sqlite3BeginTransaction(Parse*, int);
SQLITE_PRIVATE void sqlite3CommitTransaction(Parse*);
SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse*);
SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr*);
SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr*);
SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*);
SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr*, int*);
SQLITE_PRIVATE int sqlite3IsRowid(const char*);
SQLITE_PRIVATE void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
                                     int*,int,int,int,int);
SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*,int,int,int,int);
SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse*, int, int);
SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3*,Expr*);
SQLITE_PRIVATE void sqlite3TokenCopy(sqlite3*,Token*, Token*);
SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3*,IdList*);
SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3*,Select*);
SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3*);
SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(sqlite3*);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   int sqlite3SafetyOn(sqlite3*);
SQLITE_PRIVATE   int sqlite3SafetyOff(sqlite3*);
#else
# define sqlite3SafetyOn(A) 0
# define sqlite3SafetyOff(A) 0
#endif
SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3*);
SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3*);
SQLITE_PRIVATE void sqlite3ChangeCookie(Parse*, int);
SQLITE_PRIVATE void sqlite3MaterializeView(Parse*, Select*, Expr*, int);

#ifndef SQLITE_OMIT_TRIGGER
SQLITE_PRIVATE   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
SQLITE_PRIVATE   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
SQLITE_PRIVATE   void sqlite3DropTrigger(Parse*, SrcList*, int);
SQLITE_PRIVATE   void sqlite3DropTriggerPtr(Parse*, Trigger*);
SQLITE_PRIVATE   int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
SQLITE_PRIVATE   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int, 
                           int, int, u32*, u32*);
  void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
SQLITE_PRIVATE   void sqlite3DeleteTriggerStep(TriggerStep*);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
                                        ExprList*,Select*,int);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
SQLITE_PRIVATE   void sqlite3DeleteTrigger(Trigger*);
SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
#else
# define sqlite3TriggersExist(A,B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
#endif

SQLITE_PRIVATE int sqlite3JoinType(Parse*, Token*, Token*, Token*);
SQLITE_PRIVATE void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
SQLITE_PRIVATE   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
SQLITE_PRIVATE   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
SQLITE_PRIVATE   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
SQLITE_PRIVATE   void sqlite3AuthContextPop(AuthContext*);
#else
# define sqlite3AuthRead(a,b,c,d)
# define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
# define sqlite3AuthContextPush(a,b,c)
# define sqlite3AuthContextPop(a)  ((void)(a))
#endif
SQLITE_PRIVATE void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
SQLITE_PRIVATE void sqlite3Detach(Parse*, Expr*);
SQLITE_PRIVATE int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
                       int omitJournal, int nCache, int flags, Btree **ppBtree);
SQLITE_PRIVATE int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
SQLITE_PRIVATE int sqlite3FixSrcList(DbFixer*, SrcList*);
SQLITE_PRIVATE int sqlite3FixSelect(DbFixer*, Select*);
SQLITE_PRIVATE int sqlite3FixExpr(DbFixer*, Expr*);
SQLITE_PRIVATE int sqlite3FixExprList(DbFixer*, ExprList*);
SQLITE_PRIVATE int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
SQLITE_PRIVATE int sqlite3AtoF(const char *z, double*);
SQLITE_API char *sqlite3_snprintf(int,char*,const char*,...);
SQLITE_PRIVATE int sqlite3GetInt32(const char *, int*);
SQLITE_PRIVATE int sqlite3FitsIn64Bits(const char *, int);
SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *pData, int nChar);
SQLITE_PRIVATE int sqlite3Utf8CharLen(const char *pData, int nByte);
SQLITE_PRIVATE int sqlite3Utf8Read(const u8*, const u8*, const u8**);

/*
** Routines to read and write variable-length integers.  These used to
** be defined locally, but now we use the varint routines in the util.c
** file.  Code should use the MACRO forms below, as the Varint32 versions
** are coded to assume the single byte case is already handled (which 
** the MACRO form does).
*/
SQLITE_PRIVATE int sqlite3PutVarint(unsigned char*, u64);
SQLITE_PRIVATE int sqlite3PutVarint32(unsigned char*, u32);
SQLITE_PRIVATE int sqlite3GetVarint(const unsigned char *, u64 *);
SQLITE_PRIVATE int sqlite3GetVarint32(const unsigned char *, u32 *);
SQLITE_PRIVATE int sqlite3VarintLen(u64 v);

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macros take advantage this fact to provide a fast encode
** and decode of the integers in a record header.  It is faster for the common
** case where the integer is a single byte.  It is a little slower when the
** integer is two or more bytes.  But overall it is faster.
**
** The following expressions are equivalent:
**
**     x = sqlite3GetVarint32( A, &B );
**     x = sqlite3PutVarint32( A, B );
**
**     x = getVarint32( A, B );
**     x = putVarint32( A, B );
**
*/
#define getVarint32(A,B)  ((*(A)<(unsigned char)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), &(B)))
#define putVarint32(A,B)  (((B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
#define getVarint    sqlite3GetVarint
#define putVarint    sqlite3PutVarint


SQLITE_PRIVATE void sqlite3IndexAffinityStr(Vdbe *, Index *);
SQLITE_PRIVATE void sqlite3TableAffinityStr(Vdbe *, Table *);
SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2);
SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr);
SQLITE_PRIVATE int sqlite3Atoi64(const char*, i64*);
SQLITE_PRIVATE void sqlite3Error(sqlite3*, int, const char*,...);
SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
SQLITE_PRIVATE int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
SQLITE_PRIVATE const char *sqlite3ErrStr(int);
SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse);
SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
SQLITE_PRIVATE Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *, CollSeq *);
SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *, const char *);
SQLITE_PRIVATE void sqlite3VdbeSetChanges(sqlite3 *, int);

SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int);
SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
#endif
SQLITE_PRIVATE void sqlite3RootPageMoved(Db*, int, int);
SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);
SQLITE_PRIVATE void sqlite3AlterFunctions(sqlite3*);
SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);
SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*);
SQLITE_PRIVATE void sqlite3CodeSubselect(Parse *, Expr *);
SQLITE_PRIVATE int sqlite3SelectResolve(Parse *, Select *, NameContext *);
SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *, Table *, int);
SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *, Token *);
SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
SQLITE_PRIVATE char sqlite3AffinityType(const Token*);
SQLITE_PRIVATE void sqlite3Analyze(Parse*, Token*, Token*);
SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler*);
SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3*,int iDB);
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
SQLITE_PRIVATE void sqlite3AttachFunctions(sqlite3 *);
SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse*, int, int);
SQLITE_PRIVATE void sqlite3SchemaFree(void *);
SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
SQLITE_PRIVATE KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
  void (*)(sqlite3_context*,int,sqlite3_value **),
  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);
SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);

SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum*,const char*,int);
SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);
SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum*);
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);

/*
** The interface to the LEMON-generated parser
*/
SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(size_t));
SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));
SQLITE_PRIVATE void sqlite3Parser(void*, int, Token, Parse*);

SQLITE_PRIVATE int sqlite3AutoLoadExtensions(sqlite3*);
#ifndef SQLITE_OMIT_LOAD_EXTENSION
SQLITE_PRIVATE   void sqlite3CloseExtensions(sqlite3*);
#else
# define sqlite3CloseExtensions(X)
#endif

#ifndef SQLITE_OMIT_SHARED_CACHE
SQLITE_PRIVATE   void sqlite3TableLock(Parse *, int, int, u8, const char *);
#else
  #define sqlite3TableLock(v,w,x,y,z)
#endif

#ifdef SQLITE_TEST
SQLITE_PRIVATE   int sqlite3Utf8To8(unsigned char*);
#endif

#ifdef SQLITE_OMIT_VIRTUALTABLE
#  define sqlite3VtabClear(X)
#  define sqlite3VtabSync(X,Y) (Y)
#  define sqlite3VtabRollback(X)
#  define sqlite3VtabCommit(X)
#else
SQLITE_PRIVATE    void sqlite3VtabClear(Table*);
SQLITE_PRIVATE    int sqlite3VtabSync(sqlite3 *db, int rc);
SQLITE_PRIVATE    int sqlite3VtabRollback(sqlite3 *db);
SQLITE_PRIVATE    int sqlite3VtabCommit(sqlite3 *db);
#endif
SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse*,Table*);
SQLITE_PRIVATE void sqlite3VtabLock(sqlite3_vtab*);
SQLITE_PRIVATE void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
SQLITE_PRIVATE void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse*, Token*);
SQLITE_PRIVATE void sqlite3VtabArgInit(Parse*);
SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse*, Token*);
SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse*, Table*);
SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
SQLITE_PRIVATE void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
SQLITE_PRIVATE int sqlite3Reprepare(Vdbe*);
SQLITE_PRIVATE void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);


/*
** Available fault injectors.  Should be numbered beginning with 0.
*/
#define SQLITE_FAULTINJECTOR_MALLOC     0
#define SQLITE_FAULTINJECTOR_COUNT      1

/*
** The interface to the fault injector subsystem.  If the fault injector
** mechanism is disabled at compile-time then set up macros so that no
** unnecessary code is generated.
*/
#ifndef SQLITE_OMIT_BUILTIN_TEST
SQLITE_PRIVATE   void sqlite3FaultConfig(int,int,int);
SQLITE_PRIVATE   int sqlite3FaultFailures(int);
SQLITE_PRIVATE   int sqlite3FaultBenignFailures(int);
SQLITE_PRIVATE   int sqlite3FaultPending(int);
SQLITE_PRIVATE   void sqlite3FaultBeginBenign(int);
SQLITE_PRIVATE   void sqlite3FaultEndBenign(int);
SQLITE_PRIVATE   int sqlite3FaultStep(int);
#else
# define sqlite3FaultConfig(A,B,C)
# define sqlite3FaultFailures(A)         0
# define sqlite3FaultBenignFailures(A)   0
# define sqlite3FaultPending(A)          (-1)
# define sqlite3FaultBeginBenign(A)
# define sqlite3FaultEndBenign(A)
# define sqlite3FaultStep(A)             0
#endif
  
  

#define IN_INDEX_ROWID           1
#define IN_INDEX_EPH             2
#define IN_INDEX_INDEX           3
SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, int);

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
SQLITE_PRIVATE   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
SQLITE_PRIVATE   int sqlite3JournalSize(sqlite3_vfs *);
SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
#else
  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
#endif

#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
SQLITE_PRIVATE   void sqlite3ExprSetHeight(Expr *);
SQLITE_PRIVATE   int sqlite3SelectExprHeight(Select *);
#else
  #define sqlite3ExprSetHeight(x)
#endif

SQLITE_PRIVATE u32 sqlite3Get4byte(const u8*);
SQLITE_PRIVATE void sqlite3Put4byte(u8*, u32);

#ifdef SQLITE_SSE
#include "sseInt.h"
#endif

#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   void sqlite3ParserTrace(FILE*, char *);
#endif

/*
** If the SQLITE_ENABLE IOTRACE exists then the global variable
** sqlite3IoTrace is a pointer to a printf-like routine used to
** print I/O tracing messages. 
*/
#ifdef SQLITE_ENABLE_IOTRACE
# define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
SQLITE_PRIVATE   void sqlite3VdbeIOTraceSql(Vdbe*);
SQLITE_PRIVATE void (*sqlite3IoTrace)(const char*,...);
#else
# define IOTRACE(A)
# define sqlite3VdbeIOTraceSql(X)
#endif

#endif

/************** End of sqliteInt.h *******************************************/
/************** Begin file date.c ********************************************/
/*
** 2003 October 31
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.79 2008/03/20 14:03:29 drh Exp $
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
** This implemention requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar.  Historians usually
** use the Julian calendar for dates prior to 1582-10-15 and for some
** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBM 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/
#include <ctype.h>
#include <time.h>

#ifndef SQLITE_OMIT_DATETIME_FUNCS

/*
** A structure for holding a single date and time.
*/
typedef struct DateTime DateTime;
struct DateTime {
  double rJD;      /* The julian day number */
  int Y, M, D;     /* Year, month, and day */
  int h, m;        /* Hour and minutes */
  int tz;          /* Timezone offset in minutes */
  double s;        /* Seconds */
  char validYMD;   /* True if Y,M,D are valid */
  char validHMS;   /* True if h,m,s are valid */
  char validJD;    /* True if rJD is valid */
  char validTZ;    /* True if tz is valid */
};


/*
** Convert zDate into one or more integers.  Additional arguments
** come in groups of 5 as follows:
**
**       N       number of digits in the integer
**       min     minimum allowed value of the integer
**       max     maximum allowed value of the integer
**       nextC   first character after the integer
**       pVal    where to write the integers value.
**
** Conversions continue until one with nextC==0 is encountered.
** The function returns the number of successful conversions.
*/
static int getDigits(const char *zDate, ...){
  va_list ap;
  int val;
  int N;
  int min;
  int max;
  int nextC;
  int *pVal;
  int cnt = 0;
  va_start(ap, zDate);
  do{
    N = va_arg(ap, int);
    min = va_arg(ap, int);
    max = va_arg(ap, int);
    nextC = va_arg(ap, int);
    pVal = va_arg(ap, int*);
    val = 0;
    while( N-- ){
      if( !isdigit(*(u8*)zDate) ){
        goto end_getDigits;
      }
      val = val*10 + *zDate - '0';
      zDate++;
    }
    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
      goto end_getDigits;
    }
    *pVal = val;
    zDate++;
    cnt++;
  }while( nextC );
end_getDigits:
  va_end(ap);
  return cnt;
}

/*
** Read text from z[] and convert into a floating point number.  Return
** the number of digits converted.
*/
#define getValue sqlite3AtoF

/*
** Parse a timezone extension on the end of a date-time.
** The extension is of the form:
**
**        (+/-)HH:MM
**
** Or the "zulu" notation:
**
**        Z
**
** If the parse is successful, write the number of minutes
** of change in p->tz and return 0.  If a parser error occurs,
** return non-zero.
**
** A missing specifier is not considered an error.
*/
static int parseTimezone(const char *zDate, DateTime *p){
  int sgn = 0;
  int nHr, nMn;
  int c;
  while( isspace(*(u8*)zDate) ){ zDate++; }
  p->tz = 0;
  c = *zDate;
  if( c=='-' ){
    sgn = -1;
  }else if( c=='+' ){
    sgn = +1;
  }else if( c=='Z' || c=='z' ){
    zDate++;
    goto zulu_time;
  }else{
    return c!=0;
  }
  zDate++;
  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
    return 1;
  }
  zDate += 5;
  p->tz = sgn*(nMn + nHr*60);
zulu_time:
  while( isspace(*(u8*)zDate) ){ zDate++; }
  return *zDate!=0;
}

/*
** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF.
** The HH, MM, and SS must each be exactly 2 digits.  The
** fractional seconds FFFF can be one or more digits.
**
** Return 1 if there is a parsing error and 0 on success.
*/
static int parseHhMmSs(const char *zDate, DateTime *p){
  int h, m, s;
  double ms = 0.0;
  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
    return 1;
  }
  zDate += 5;
  if( *zDate==':' ){
    zDate++;
    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
      return 1;
    }
    zDate += 2;
    if( *zDate=='.' && isdigit((u8)zDate[1]) ){
      double rScale = 1.0;
      zDate++;
      while( isdigit(*(u8*)zDate) ){
        ms = ms*10.0 + *zDate - '0';
        rScale *= 10.0;
        zDate++;
      }
      ms /= rScale;
    }
  }else{
    s = 0;
  }
  p->validJD = 0;
  p->validHMS = 1;
  p->h = h;
  p->m = m;
  p->s = s + ms;
  if( parseTimezone(zDate, p) ) return 1;
  p->validTZ = p->tz!=0;
  return 0;
}

/*
** Convert from YYYY-MM-DD HH:MM:SS to julian day.  We always assume
** that the YYYY-MM-DD is according to the Gregorian calendar.
**
** Reference:  Meeus page 61
*/
static void computeJD(DateTime *p){
  int Y, M, D, A, B, X1, X2;

  if( p->validJD ) return;
  if( p->validYMD ){
    Y = p->Y;
    M = p->M;
    D = p->D;
  }else{
    Y = 2000;  /* If no YMD specified, assume 2000-Jan-01 */
    M = 1;
    D = 1;
  }
  if( M<=2 ){
    Y--;
    M += 12;
  }
  A = Y/100;
  B = 2 - A + (A/4);
  X1 = 365.25*(Y+4716);
  X2 = 30.6001*(M+1);
  p->rJD = X1 + X2 + D + B - 1524.5;
  p->validJD = 1;
  if( p->validHMS ){
    p->rJD += (p->h*3600.0 + p->m*60.0 + p->s)/86400.0;
    if( p->validTZ ){
      p->rJD -= p->tz*60/86400.0;
      p->validYMD = 0;
      p->validHMS = 0;
      p->validTZ = 0;
    }
  }
}

/*
** Parse dates of the form
**
**     YYYY-MM-DD HH:MM:SS.FFF
**     YYYY-MM-DD HH:MM:SS
**     YYYY-MM-DD HH:MM
**     YYYY-MM-DD
**
** Write the result into the DateTime structure and return 0
** on success and 1 if the input string is not a well-formed
** date.
*/
static int parseYyyyMmDd(const char *zDate, DateTime *p){
  int Y, M, D, neg;

  if( zDate[0]=='-' ){
    zDate++;
    neg = 1;
  }else{
    neg = 0;
  }
  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
    return 1;
  }
  zDate += 10;
  while( isspace(*(u8*)zDate) || 'T'==*(u8*)zDate ){ zDate++; }
  if( parseHhMmSs(zDate, p)==0 ){
    /* We got the time */
  }else if( *zDate==0 ){
    p->validHMS = 0;
  }else{
    return 1;
  }
  p->validJD = 0;
  p->validYMD = 1;
  p->Y = neg ? -Y : Y;
  p->M = M;
  p->D = D;
  if( p->validTZ ){
    computeJD(p);
  }
  return 0;
}

/*
** Attempt to parse the given string into a Julian Day Number.  Return
** the number of errors.
**
** The following are acceptable forms for the input string:
**
**      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM
**      DDDD.DD 
**      now
**
** In the first form, the +/-HH:MM is always optional.  The fractional
** seconds extension (the ".FFF") is optional.  The seconds portion
** (":SS.FFF") is option.  The year and date can be omitted as long
** as there is a time string.  The time string can be omitted as long
** as there is a year and date.
*/
static int parseDateOrTime(
  sqlite3_context *context, 
  const char *zDate, 
  DateTime *p
){
  memset(p, 0, sizeof(*p));
  if( parseYyyyMmDd(zDate,p)==0 ){
    return 0;
  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
  }else if( sqlite3StrICmp(zDate,"now")==0){
    double r;
    sqlite3 *db = sqlite3_context_db_handle(context);
    sqlite3OsCurrentTime(db->pVfs, &r);
    p->rJD = r;
    p->validJD = 1;
    return 0;
  }else if( sqlite3IsNumber(zDate, 0, SQLITE_UTF8) ){
    getValue(zDate, &p->rJD);
    p->validJD = 1;
    return 0;
  }
  return 1;
}

/*
** Compute the Year, Month, and Day from the julian day number.
*/
static void computeYMD(DateTime *p){
  int Z, A, B, C, D, E, X1;
  if( p->validYMD ) return;
  if( !p->validJD ){
    p->Y = 2000;
    p->M = 1;
    p->D = 1;
  }else{
    Z = p->rJD + 0.5;
    A = (Z - 1867216.25)/36524.25;
    A = Z + 1 + A - (A/4);
    B = A + 1524;
    C = (B - 122.1)/365.25;
    D = 365.25*C;
    E = (B-D)/30.6001;
    X1 = 30.6001*E;
    p->D = B - D - X1;
    p->M = E<14 ? E-1 : E-13;
    p->Y = p->M>2 ? C - 4716 : C - 4715;
  }
  p->validYMD = 1;
}

/*
** Compute the Hour, Minute, and Seconds from the julian day number.
*/
static void computeHMS(DateTime *p){
  int Z, s;
  if( p->validHMS ) return;
  computeJD(p);
  Z = p->rJD + 0.5;
  s = (p->rJD + 0.5 - Z)*86400000.0 + 0.5;
  p->s = 0.001*s;
  s = p->s;
  p->s -= s;
  p->h = s/3600;
  s -= p->h*3600;
  p->m = s/60;
  p->s += s - p->m*60;
  p->validHMS = 1;
}

/*
** Compute both YMD and HMS
*/
static void computeYMD_HMS(DateTime *p){
  computeYMD(p);
  computeHMS(p);
}

/*
** Clear the YMD and HMS and the TZ
*/
static void clearYMD_HMS_TZ(DateTime *p){
  p->validYMD = 0;
  p->validHMS = 0;
  p->validTZ = 0;
}

/*
** Compute the difference (in days) between localtime and UTC (a.k.a. GMT)
** for the time value p where p is in UTC.
*/
static double localtimeOffset(DateTime *p){
  DateTime x, y;
  time_t t;
  x = *p;
  computeYMD_HMS(&x);
  if( x.Y<1971 || x.Y>=2038 ){
    x.Y = 2000;
    x.M = 1;
    x.D = 1;
    x.h = 0;
    x.m = 0;
    x.s = 0.0;
  } else {
    int s = x.s + 0.5;
    x.s = s;
  }
  x.tz = 0;
  x.validJD = 0;
  computeJD(&x);
  t = (x.rJD-2440587.5)*86400.0 + 0.5;
#ifdef HAVE_LOCALTIME_R
  {
    struct tm sLocal;
    localtime_r(&t, &sLocal);
    y.Y = sLocal.tm_year + 1900;
    y.M = sLocal.tm_mon + 1;
    y.D = sLocal.tm_mday;
    y.h = sLocal.tm_hour;
    y.m = sLocal.tm_min;
    y.s = sLocal.tm_sec;
  }
#else
  {
    struct tm *pTm;
    sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
    pTm = localtime(&t);
    y.Y = pTm->tm_year + 1900;
    y.M = pTm->tm_mon + 1;
    y.D = pTm->tm_mday;
    y.h = pTm->tm_hour;
    y.m = pTm->tm_min;
    y.s = pTm->tm_sec;
    sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
  }
#endif
  y.validYMD = 1;
  y.validHMS = 1;
  y.validJD = 0;
  y.validTZ = 0;
  computeJD(&y);
  return y.rJD - x.rJD;
}

/*
** Process a modifier to a date-time stamp.  The modifiers are
** as follows:
**
**     NNN days
**     NNN hours
**     NNN minutes
**     NNN.NNNN seconds
**     NNN months
**     NNN years
**     start of month
**     start of year
**     start of week
**     start of day
**     weekday N
**     unixepoch
**     localtime
**     utc
**
** Return 0 on success and 1 if there is any kind of error.
*/
static int parseModifier(const char *zMod, DateTime *p){
  int rc = 1;
  int n;
  double r;
  char *z, zBuf[30];
  z = zBuf;
  for(n=0; n<sizeof(zBuf)-1 && zMod[n]; n++){
    z[n] = tolower(zMod[n]);
  }
  z[n] = 0;
  switch( z[0] ){
    case 'l': {
      /*    localtime
      **
      ** Assuming the current time value is UTC (a.k.a. GMT), shift it to
      ** show local time.
      */
      if( strcmp(z, "localtime")==0 ){
        computeJD(p);
        p->rJD += localtimeOffset(p);
        clearYMD_HMS_TZ(p);
        rc = 0;
      }
      break;
    }
    case 'u': {
      /*
      **    unixepoch
      **
      ** Treat the current value of p->rJD as the number of
      ** seconds since 1970.  Convert to a real julian day number.
      */
      if( strcmp(z, "unixepoch")==0 && p->validJD ){
        p->rJD = p->rJD/86400.0 + 2440587.5;
        clearYMD_HMS_TZ(p);
        rc = 0;
      }else if( strcmp(z, "utc")==0 ){
        double c1;
        computeJD(p);
        c1 = localtimeOffset(p);
        p->rJD -= c1;
        clearYMD_HMS_TZ(p);
        p->rJD += c1 - localtimeOffset(p);
        rc = 0;
      }
      break;
    }
    case 'w': {
      /*
      **    weekday N
      **
      ** Move the date to the same time on the next occurrence of
      ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the
      ** date is already on the appropriate weekday, this is a no-op.
      */
      if( strncmp(z, "weekday ", 8)==0 && getValue(&z[8],&r)>0
                 && (n=r)==r && n>=0 && r<7 ){
        int Z;
        computeYMD_HMS(p);
        p->validTZ = 0;
        p->validJD = 0;
        computeJD(p);
        Z = p->rJD + 1.5;
        Z %= 7;
        if( Z>n ) Z -= 7;
        p->rJD += n - Z;
        clearYMD_HMS_TZ(p);
        rc = 0;
      }
      break;
    }
    case 's': {
      /*
      **    start of TTTTT
      **
      ** Move the date backwards to the beginning of the current day,
      ** or month or year.
      */
      if( strncmp(z, "start of ", 9)!=0 ) break;
      z += 9;
      computeYMD(p);
      p->validHMS = 1;
      p->h = p->m = 0;
      p->s = 0.0;
      p->validTZ = 0;
      p->validJD = 0;
      if( strcmp(z,"month")==0 ){
        p->D = 1;
        rc = 0;
      }else if( strcmp(z,"year")==0 ){
        computeYMD(p);
        p->M = 1;
        p->D = 1;
        rc = 0;
      }else if( strcmp(z,"day")==0 ){
        rc = 0;
      }
      break;
    }
    case '+':
    case '-':
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9': {
      n = getValue(z, &r);
      assert( n>=1 );
      if( z[n]==':' ){
        /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the
        ** specified number of hours, minutes, seconds, and fractional seconds
        ** to the time.  The ".FFF" may be omitted.  The ":SS.FFF" may be
        ** omitted.
        */
        const char *z2 = z;
        DateTime tx;
        int day;
        if( !isdigit(*(u8*)z2) ) z2++;
        memset(&tx, 0, sizeof(tx));
        if( parseHhMmSs(z2, &tx) ) break;
        computeJD(&tx);
        tx.rJD -= 0.5;
        day = (int)tx.rJD;
        tx.rJD -= day;
        if( z[0]=='-' ) tx.rJD = -tx.rJD;
        computeJD(p);
        clearYMD_HMS_TZ(p);
        p->rJD += tx.rJD;
        rc = 0;
        break;
      }
      z += n;
      while( isspace(*(u8*)z) ) z++;
      n = strlen(z);
      if( n>10 || n<3 ) break;
      if( z[n-1]=='s' ){ z[n-1] = 0; n--; }
      computeJD(p);
      rc = 0;
      if( n==3 && strcmp(z,"day")==0 ){
        p->rJD += r;
      }else if( n==4 && strcmp(z,"hour")==0 ){
        p->rJD += r/24.0;
      }else if( n==6 && strcmp(z,"minute")==0 ){
        p->rJD += r/(24.0*60.0);
      }else if( n==6 && strcmp(z,"second")==0 ){
        p->rJD += r/(24.0*60.0*60.0);
      }else if( n==5 && strcmp(z,"month")==0 ){
        int x, y;
        computeYMD_HMS(p);
        p->M += r;
        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
        p->Y += x;
        p->M -= x*12;
        p->validJD = 0;
        computeJD(p);
        y = r;
        if( y!=r ){
          p->rJD += (r - y)*30.0;
        }
      }else if( n==4 && strcmp(z,"year")==0 ){
        computeYMD_HMS(p);
        p->Y += r;
        p->validJD = 0;
        computeJD(p);
      }else{
        rc = 1;
      }
      clearYMD_HMS_TZ(p);
      break;
    }
    default: {
      break;
    }
  }
  return rc;
}

/*
** Process time function arguments.  argv[0] is a date-time stamp.
** argv[1] and following are modifiers.  Parse them all and write
** the resulting time into the DateTime structure p.  Return 0
** on success and 1 if there are any errors.
**
** If there are zero parameters (if even argv[0] is undefined)
** then assume a default value of "now" for argv[0].
*/
static int isDate(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv, 
  DateTime *p
){
  int i;
  const unsigned char *z;
  static const unsigned char zDflt[] = "now";
  if( argc==0 ){
    z = zDflt;
  }else{
    z = sqlite3_value_text(argv[0]);
  }
  if( !z || parseDateOrTime(context, (char*)z, p) ){
    return 1;
  }
  for(i=1; i<argc; i++){
    if( (z = sqlite3_value_text(argv[i]))==0 || parseModifier((char*)z, p) ){
      return 1;
    }
  }
  return 0;
}


/*
** The following routines implement the various date and time functions
** of SQLite.
*/

/*
**    julianday( TIMESTRING, MOD, MOD, ...)
**
** Return the julian day number of the date specified in the arguments
*/
static void juliandayFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    computeJD(&x);
    sqlite3_result_double(context, x.rJD);
  }
}

/*
**    datetime( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD HH:MM:SS
*/
static void datetimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    char zBuf[100];
    computeYMD_HMS(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d %02d:%02d:%02d",
                     x.Y, x.M, x.D, x.h, x.m, (int)(x.s));
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    time( TIMESTRING, MOD, MOD, ...)
**
** Return HH:MM:SS
*/
static void timeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    char zBuf[100];
    computeHMS(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s);
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    date( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD
*/
static void dateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    char zBuf[100];
    computeYMD(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D);
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
  }
}

/*
**    strftime( FORMAT, TIMESTRING, MOD, MOD, ...)
**
** Return a string described by FORMAT.  Conversions as follows:
**
**   %d  day of month
**   %f  ** fractional seconds  SS.SSS
**   %H  hour 00-24
**   %j  day of year 000-366
**   %J  ** Julian day number
**   %m  month 01-12
**   %M  minute 00-59
**   %s  seconds since 1970-01-01
**   %S  seconds 00-59
**   %w  day of week 0-6  sunday==0
**   %W  week of year 00-53
**   %Y  year 0000-9999
**   %%  %
*/
static void strftimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  u64 n;
  int i, j;
  char *z;
  const char *zFmt = (const char*)sqlite3_value_text(argv[0]);
  char zBuf[100];
  if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;
  for(i=0, n=1; zFmt[i]; i++, n++){
    if( zFmt[i]=='%' ){
      switch( zFmt[i+1] ){
        case 'd':
        case 'H':
        case 'm':
        case 'M':
        case 'S':
        case 'W':
          n++;
          /* fall thru */
        case 'w':
        case '%':
          break;
        case 'f':
          n += 8;
          break;
        case 'j':
          n += 3;
          break;
        case 'Y':
          n += 8;
          break;
        case 's':
        case 'J':
          n += 50;
          break;
        default:
          return;  /* ERROR.  return a NULL */
      }
      i++;
    }
  }
  if( n<sizeof(zBuf) ){
    z = zBuf;
  }else if( n>sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH] ){
    sqlite3_result_error_toobig(context);
    return;
  }else{
    z = sqlite3_malloc( n );
    if( z==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  computeJD(&x);
  computeYMD_HMS(&x);
  for(i=j=0; zFmt[i]; i++){
    if( zFmt[i]!='%' ){
      z[j++] = zFmt[i];
    }else{
      i++;
      switch( zFmt[i] ){
        case 'd':  sqlite3_snprintf(3, &z[j],"%02d",x.D); j+=2; break;
        case 'f': {
          double s = x.s;
          if( s>59.999 ) s = 59.999;
          sqlite3_snprintf(7, &z[j],"%06.3f", s);
          j += strlen(&z[j]);
          break;
        }
        case 'H':  sqlite3_snprintf(3, &z[j],"%02d",x.h); j+=2; break;
        case 'W': /* Fall thru */
        case 'j': {
          int nDay;             /* Number of days since 1st day of year */
          DateTime y = x;
          y.validJD = 0;
          y.M = 1;
          y.D = 1;
          computeJD(&y);
          nDay = x.rJD - y.rJD + 0.5;
          if( zFmt[i]=='W' ){
            int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */
            wd = ((int)(x.rJD+0.5)) % 7;
            sqlite3_snprintf(3, &z[j],"%02d",(nDay+7-wd)/7);
            j += 2;
          }else{
            sqlite3_snprintf(4, &z[j],"%03d",nDay+1);
            j += 3;
          }
          break;
        }
        case 'J': {
          sqlite3_snprintf(20, &z[j],"%.16g",x.rJD);
          j+=strlen(&z[j]);
          break;
        }
        case 'm':  sqlite3_snprintf(3, &z[j],"%02d",x.M); j+=2; break;
        case 'M':  sqlite3_snprintf(3, &z[j],"%02d",x.m); j+=2; break;
        case 's': {
          sqlite3_snprintf(30,&z[j],"%d",
                           (int)((x.rJD-2440587.5)*86400.0 + 0.5));
          j += strlen(&z[j]);
          break;
        }
        case 'S':  sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break;
        case 'w':  z[j++] = (((int)(x.rJD+1.5)) % 7) + '0'; break;
        case 'Y':  sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=strlen(&z[j]);break;
        default:   z[j++] = '%'; break;
      }
    }
  }
  z[j] = 0;
  sqlite3_result_text(context, z, -1,
                      z==zBuf ? SQLITE_TRANSIENT : sqlite3_free);
}

/*
** current_time()
**
** This function returns the same value as time('now').
*/
static void ctimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  timeFunc(context, 0, 0);
}

/*
** current_date()
**
** This function returns the same value as date('now').
*/
static void cdateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  dateFunc(context, 0, 0);
}

/*
** current_timestamp()
**
** This function returns the same value as datetime('now').
*/
static void ctimestampFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  datetimeFunc(context, 0, 0);
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

#ifdef SQLITE_OMIT_DATETIME_FUNCS
/*
** If the library is compiled to omit the full-scale date and time
** handling (to get a smaller binary), the following minimal version
** of the functions current_time(), current_date() and current_timestamp()
** are included instead. This is to support column declarations that
** include "DEFAULT CURRENT_TIME" etc.
**
** This function uses the C-library functions time(), gmtime()
** and strftime(). The format string to pass to strftime() is supplied
** as the user-data for the function.
*/
static void currentTimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  time_t t;
  char *zFormat = (char *)sqlite3_user_data(context);
  sqlite3 *db;
  double rT;
  char zBuf[20];

  db = sqlite3_context_db_handle(context);
  sqlite3OsCurrentTime(db->pVfs, &rT);
  t = 86400.0*(rT - 2440587.5) + 0.5;
#ifdef HAVE_GMTIME_R
  {
    struct tm sNow;
    gmtime_r(&t, &sNow);
    strftime(zBuf, 20, zFormat, &sNow);
  }
#else
  {
    struct tm *pTm;
    sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
    pTm = gmtime(&t);
    strftime(zBuf, 20, zFormat, pTm);
    sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
  }
#endif

  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}
#endif

/*
** This function registered all of the above C functions as SQL
** functions.  This should be the only routine in this file with
** external linkage.
*/
SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(sqlite3 *db){
#ifndef SQLITE_OMIT_DATETIME_FUNCS
  static const struct {
     char *zName;
     int nArg;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFuncs[] = {
    { "julianday", -1, juliandayFunc   },
    { "date",      -1, dateFunc        },
    { "time",      -1, timeFunc        },
    { "datetime",  -1, datetimeFunc    },
    { "strftime",  -1, strftimeFunc    },
    { "current_time",       0, ctimeFunc      },
    { "current_timestamp",  0, ctimestampFunc },
    { "current_date",       0, cdateFunc      },
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
        SQLITE_UTF8, 0, aFuncs[i].xFunc, 0, 0);
  }
#else
  static const struct {
     char *zName;
     char *zFormat;
  } aFuncs[] = {
    { "current_time", "%H:%M:%S" },
    { "current_date", "%Y-%m-%d" },
    { "current_timestamp", "%Y-%m-%d %H:%M:%S" }
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3CreateFunc(db, aFuncs[i].zName, 0, SQLITE_UTF8, 
        aFuncs[i].zFormat, currentTimeFunc, 0, 0);
  }
#endif
}

/************** End of date.c ************************************************/
/************** Begin file os.c **********************************************/
/*
** 2005 November 29
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains OS interface code that is common to all
** architectures.
*/
#define _SQLITE_OS_C_ 1
#undef _SQLITE_OS_C_

/*
** The default SQLite sqlite3_vfs implementations do not allocate
** memory (actually, os_unix.c allocates a small amount of memory
** from within OsOpen()), but some third-party implementations may.
** So we test the effects of a malloc() failing and the sqlite3OsXXX()
** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.
**
** The following functions are instrumented for malloc() failure 
** testing:
**
**     sqlite3OsOpen()
**     sqlite3OsRead()
**     sqlite3OsWrite()
**     sqlite3OsSync()
**     sqlite3OsLock()
**
*/
#if defined(SQLITE_TEST) && (OS_WIN==0)
  #define DO_OS_MALLOC_TEST if (1) {            \
    void *pTstAlloc = sqlite3_malloc(10);       \
    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;  \
    sqlite3_free(pTstAlloc);                    \
  }
#else
  #define DO_OS_MALLOC_TEST
#endif

/*
** The following routines are convenience wrappers around methods
** of the sqlite3_file object.  This is mostly just syntactic sugar. All
** of this would be completely automatic if SQLite were coded using
** C++ instead of plain old C.
*/
SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file *pId){
  int rc = SQLITE_OK;
  if( pId->pMethods ){
    rc = pId->pMethods->xClose(pId);
    pId->pMethods = 0;
  }
  return rc;
}
SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
  DO_OS_MALLOC_TEST;
  return id->pMethods->xRead(id, pBuf, amt, offset);
}
SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){
  DO_OS_MALLOC_TEST;
  return id->pMethods->xWrite(id, pBuf, amt, offset);
}
SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file *id, i64 size){
  return id->pMethods->xTruncate(id, size);
}
SQLITE_PRIVATE int sqlite3OsSync(sqlite3_file *id, int flags){
  DO_OS_MALLOC_TEST;
  return id->pMethods->xSync(id, flags);
}
SQLITE_PRIVATE int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){
  return id->pMethods->xFileSize(id, pSize);
}
SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file *id, int lockType){
  DO_OS_MALLOC_TEST;
  return id->pMethods->xLock(id, lockType);
}
SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file *id, int lockType){
  return id->pMethods->xUnlock(id, lockType);
}
SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id){
  return id->pMethods->xCheckReservedLock(id);
}
SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
  return id->pMethods->xFileControl(id,op,pArg);
}
SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id){
  int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;
  return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);
}
SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id){
  return id->pMethods->xDeviceCharacteristics(id);
}

/*
** The next group of routines are convenience wrappers around the
** VFS methods.
*/
SQLITE_PRIVATE int sqlite3OsOpen(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  sqlite3_file *pFile, 
  int flags, 
  int *pFlagsOut
){
  DO_OS_MALLOC_TEST;
  return pVfs->xOpen(pVfs, zPath, pFile, flags, pFlagsOut);
}
SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return pVfs->xDelete(pVfs, zPath, dirSync);
}
SQLITE_PRIVATE int sqlite3OsAccess(sqlite3_vfs *pVfs, const char *zPath, int flags){
  int rc;
#ifdef SQLITE_TEST
  void *pTstAlloc = sqlite3_malloc(10);
  if (!pTstAlloc) return -1;
  sqlite3_free(pTstAlloc);
#endif
  rc = pVfs->xAccess(pVfs, zPath, flags);
  return rc;
}
SQLITE_PRIVATE int sqlite3OsGetTempname(sqlite3_vfs *pVfs, int nBufOut, char *zBufOut){
  return pVfs->xGetTempname(pVfs, nBufOut, zBufOut);
}
SQLITE_PRIVATE int sqlite3OsFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nPathOut, 
  char *zPathOut
){
  return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
}
SQLITE_PRIVATE void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  return pVfs->xDlOpen(pVfs, zPath);
}
SQLITE_PRIVATE void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  pVfs->xDlError(pVfs, nByte, zBufOut);
}
SQLITE_PRIVATE void *sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
  return pVfs->xDlSym(pVfs, pHandle, zSymbol);
}
SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){
  pVfs->xDlClose(pVfs, pHandle);
}
SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  return pVfs->xRandomness(pVfs, nByte, zBufOut);
}
SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
  return pVfs->xSleep(pVfs, nMicro);
}
SQLITE_PRIVATE int sqlite3OsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return pVfs->xCurrentTime(pVfs, pTimeOut);
}

SQLITE_PRIVATE int sqlite3OsOpenMalloc(
  sqlite3_vfs *pVfs, 
  const char *zFile, 
  sqlite3_file **ppFile, 
  int flags,
  int *pOutFlags
){
  int rc = SQLITE_NOMEM;
  sqlite3_file *pFile;
  pFile = (sqlite3_file *)sqlite3_malloc(pVfs->szOsFile);
  if( pFile ){
    rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);
    if( rc!=SQLITE_OK ){
      sqlite3_free(pFile);
    }else{
      *ppFile = pFile;
    }
  }
  return rc;
}
SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *pFile){
  int rc = SQLITE_OK;
  assert( pFile );
  rc = sqlite3OsClose(pFile);
  sqlite3_free(pFile);
  return rc;
}

/*
** The list of all registered VFS implementations.  This list is
** initialized to the single VFS returned by sqlite3OsDefaultVfs()
** upon the first call to sqlite3_vfs_find().
*/
static sqlite3_vfs *vfsList = 0;

/*
** Locate a VFS by name.  If no name is given, simply return the
** first VFS on the list.
*/
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
#ifndef SQLITE_MUTEX_NOOP
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
  sqlite3_vfs *pVfs = 0;
  static int isInit = 0;
  sqlite3_mutex_enter(mutex);
  if( !isInit ){
    vfsList = sqlite3OsDefaultVfs();
    isInit = 1;
  }
  for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
    if( zVfs==0 ) break;
    if( strcmp(zVfs, pVfs->zName)==0 ) break;
  }
  sqlite3_mutex_leave(mutex);
  return pVfs;
}

/*
** Unlink a VFS from the linked list
*/
static void vfsUnlink(sqlite3_vfs *pVfs){
  assert( sqlite3_mutex_held(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)) );
  if( pVfs==0 ){
    /* No-op */
  }else if( vfsList==pVfs ){
    vfsList = pVfs->pNext;
  }else if( vfsList ){
    sqlite3_vfs *p = vfsList;
    while( p->pNext && p->pNext!=pVfs ){
      p = p->pNext;
    }
    if( p->pNext==pVfs ){
      p->pNext = pVfs->pNext;
    }
  }
}

/*
** Register a VFS with the system.  It is harmless to register the same
** VFS multiple times.  The new VFS becomes the default if makeDflt is
** true.
*/
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
#ifndef SQLITE_MUTEX_NOOP
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
  sqlite3_vfs_find(0);  /* Make sure we are initialized */
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  if( makeDflt || vfsList==0 ){
    pVfs->pNext = vfsList;
    vfsList = pVfs;
  }else{
    pVfs->pNext = vfsList->pNext;
    vfsList->pNext = pVfs;
  }
  assert(vfsList);
  sqlite3_mutex_leave(mutex);
  return SQLITE_OK;
}

/*
** Unregister a VFS so that it is no longer accessible.
*/
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
#ifndef SQLITE_MUTEX_NOOP
  sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  sqlite3_mutex_leave(mutex);
  return SQLITE_OK;
}

/*
** Provide a default sqlite3OsDefaultVfs() implementation in the
** cases where none of the standard backends are used.
*/
#if !OS_UNIX && !OS_WIN && !OS_OS2
SQLITE_PRIVATE sqlite3_vfs *sqlite3OsDefaultVfs(void){ return 0; }
#endif

/************** End of os.c **************************************************/
/************** Begin file fault.c *******************************************/
/*
** 2008 Jan 22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement a fault-injector used for
** testing and verification of SQLite.
**
** Subsystems within SQLite can call sqlite3FaultStep() to see if
** they should simulate a fault.  sqlite3FaultStep() normally returns
** zero but will return non-zero if a fault should be simulated.
** Fault injectors can be used, for example, to simulate memory
** allocation failures or I/O errors.
**
** The fault injector is omitted from the code if SQLite is
** compiled with -DSQLITE_OMIT_BUILTIN_TEST=1.  There is a very
** small performance hit for leaving the fault injector in the code.
** Commerical products will probably want to omit the fault injector
** from production builds.  But safety-critical systems who work
** under the motto "fly what you test and test what you fly" may
** choose to leave the fault injector enabled even in production.
*/

#ifndef SQLITE_OMIT_BUILTIN_TEST

/*
** There can be various kinds of faults.  For example, there can be
** a memory allocation failure.  Or an I/O failure.  For each different
** fault type, there is a separate FaultInjector structure to keep track
** of the status of that fault.
*/
static struct FaultInjector {
  int iCountdown;   /* Number of pending successes before we hit a failure */
  int nRepeat;      /* Number of times to repeat the failure */
  int nBenign;      /* Number of benign failures seen since last config */
  int nFail;        /* Number of failures seen since last config */
  u8 enable;        /* True if enabled */
  i16 benign;       /* Positive if next failure will be benign */
} aFault[SQLITE_FAULTINJECTOR_COUNT];

/*
** This routine configures and enables a fault injector.  After
** calling this routine, aFaultStep() will return false (zero)
** nDelay times, then it will return true nRepeat times,
** then it will again begin returning false.
*/
SQLITE_PRIVATE void sqlite3FaultConfig(int id, int nDelay, int nRepeat){
  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
  aFault[id].iCountdown = nDelay;
  aFault[id].nRepeat = nRepeat;
  aFault[id].nBenign = 0;
  aFault[id].nFail = 0;
  aFault[id].enable = nDelay>=0;
  aFault[id].benign = 0;
}

/*
** Return the number of faults (both hard and benign faults) that have
** occurred since the injector was last configured.
*/
SQLITE_PRIVATE int sqlite3FaultFailures(int id){
  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
  return aFault[id].nFail;
}

/*
** Return the number of benign faults that have occurred since the
** injector was last configured.
*/
SQLITE_PRIVATE int sqlite3FaultBenignFailures(int id){
  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
  return aFault[id].nBenign;
}

/*
** Return the number of successes that will occur before the next failure.
** If no failures are scheduled, return -1.
*/
SQLITE_PRIVATE int sqlite3FaultPending(int id){
  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
  if( aFault[id].enable ){
    return aFault[id].iCountdown;
  }else{
    return -1;
  }
}

/* 
** After this routine causes subsequent faults to be either benign
** or hard (not benign), according to the "enable" parameter.
**
** Most faults are hard.  In other words, most faults cause
** an error to be propagated back up to the application interface.
** However, sometimes a fault is easily recoverable.  For example,
** if a malloc fails while resizing a hash table, this is completely
** recoverable simply by not carrying out the resize.  The hash table
** will continue to function normally.  So a malloc failure during
** a hash table resize is a benign fault.  
*/
SQLITE_PRIVATE void sqlite3FaultBeginBenign(int id){
  if( id<0 ){
    for(id=0; id<SQLITE_FAULTINJECTOR_COUNT; id++){
      aFault[id].benign++;
    }
  }else{
    assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
    aFault[id].benign++;
  }
}
SQLITE_PRIVATE void sqlite3FaultEndBenign(int id){
  if( id<0 ){
    for(id=0; id<SQLITE_FAULTINJECTOR_COUNT; id++){
      assert( aFault[id].benign>0 );
      aFault[id].benign--;
    }
  }else{
    assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
    assert( aFault[id].benign>0 );
    aFault[id].benign--;
  }
}

/*
** This routine exists as a place to set a breakpoint that will
** fire on any simulated fault.
*/
static void sqlite3Fault(void){
  static int cnt = 0;
  cnt++;
}


/*
** Check to see if a fault should be simulated.  Return true to simulate
** the fault.  Return false if the fault should not be simulated.
*/
SQLITE_PRIVATE int sqlite3FaultStep(int id){
  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
  if( likely(!aFault[id].enable) ){
    return 0;
  }
  if( aFault[id].iCountdown>0 ){
    aFault[id].iCountdown--;
    return 0;
  }
  sqlite3Fault();
  aFault[id].nFail++;
  if( aFault[id].benign>0 ){
    aFault[id].nBenign++;
  }
  aFault[id].nRepeat--;
  if( aFault[id].nRepeat<=0 ){
    aFault[id].enable = 0;
  }
  return 1;  
}

#endif /* SQLITE_OMIT_BUILTIN_TEST */

/************** End of fault.c ***********************************************/
/************** Begin file mem1.c ********************************************/
/*
** 2007 August 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement a memory
** allocation subsystem for use by SQLite.  
**
** $Id: mem1.c,v 1.17 2008/03/18 00:07:11 drh Exp $
*/

/*
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/
#ifdef SQLITE_SYSTEM_MALLOC

/*
** All of the static variables used by this module are collected
** into a single structure named "mem".  This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
static struct {
  /*
  ** The alarm callback and its arguments.  The mem.mutex lock will
  ** be held while the callback is running.  Recursive calls into
  ** the memory subsystem are allowed, but no new callbacks will be
  ** issued.  The alarmBusy variable is set to prevent recursive
  ** callbacks.
  */
  sqlite3_int64 alarmThreshold;
  void (*alarmCallback)(void*, sqlite3_int64,int);
  void *alarmArg;
  int alarmBusy;
  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;
  
  /*
  ** Current allocation and high-water mark.
  */
  sqlite3_int64 nowUsed;
  sqlite3_int64 mxUsed;
  
 
} mem;

/*
** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
*/
static void enterMem(void){
  if( mem.mutex==0 ){
    mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
  }
  sqlite3_mutex_enter(mem.mutex);
}

/*
** Return the amount of memory currently checked out.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
  sqlite3_int64 n;
  enterMem();
  n = mem.nowUsed;
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Return the maximum amount of memory that has ever been
** checked out since either the beginning of this process
** or since the most recent reset.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 n;
  enterMem();
  n = mem.mxUsed;
  if( resetFlag ){
    mem.mxUsed = mem.nowUsed;
  }
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Change the alarm callback
*/
SQLITE_API int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  enterMem();
  mem.alarmCallback = xCallback;
  mem.alarmArg = pArg;
  mem.alarmThreshold = iThreshold;
  sqlite3_mutex_leave(mem.mutex);
  return SQLITE_OK;
}

/*
** Trigger the alarm 
*/
static void sqlite3MemsysAlarm(int nByte){
  void (*xCallback)(void*,sqlite3_int64,int);
  sqlite3_int64 nowUsed;
  void *pArg;
  if( mem.alarmCallback==0 || mem.alarmBusy  ) return;
  mem.alarmBusy = 1;
  xCallback = mem.alarmCallback;
  nowUsed = mem.nowUsed;
  pArg = mem.alarmArg;
  sqlite3_mutex_leave(mem.mutex);
  xCallback(pArg, nowUsed, nByte);
  sqlite3_mutex_enter(mem.mutex);
  mem.alarmBusy = 0;
}

/*
** Allocate nBytes of memory
*/
SQLITE_API void *sqlite3_malloc(int nBytes){
  sqlite3_int64 *p = 0;
  if( nBytes>0 ){
    enterMem();
    if( mem.alarmCallback!=0 && mem.nowUsed+nBytes>=mem.alarmThreshold ){
      sqlite3MemsysAlarm(nBytes);
    }
    if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
      p = 0;
    }else{
      p = malloc(nBytes+8);
      if( p==0 ){
        sqlite3MemsysAlarm(nBytes);
        p = malloc(nBytes+8);
      }
    }
    if( p ){
      p[0] = nBytes;
      p++;
      mem.nowUsed += nBytes;
      if( mem.nowUsed>mem.mxUsed ){
        mem.mxUsed = mem.nowUsed;
      }
    }
    sqlite3_mutex_leave(mem.mutex);
  }
  return (void*)p; 
}

/*
** Free memory.
*/
SQLITE_API void sqlite3_free(void *pPrior){
  sqlite3_int64 *p;
  int nByte;
  if( pPrior==0 ){
    return;
  }
  assert( mem.mutex!=0 );
  p = pPrior;
  p--;
  nByte = (int)*p;
  sqlite3_mutex_enter(mem.mutex);
  mem.nowUsed -= nByte;
  free(p);
  sqlite3_mutex_leave(mem.mutex);  
}

/*
** Return the number of bytes allocated at p.
*/
SQLITE_PRIVATE int sqlite3MallocSize(void *p){
  sqlite3_int64 *pInt;
  if( !p ) return 0;
  pInt = p;
  return pInt[-1];
}

/*
** Change the size of an existing memory allocation
*/
SQLITE_API void *sqlite3_realloc(void *pPrior, int nBytes){
  int nOld;
  sqlite3_int64 *p;
  if( pPrior==0 ){
    return sqlite3_malloc(nBytes);
  }
  if( nBytes<=0 ){
    sqlite3_free(pPrior);
    return 0;
  }
  p = pPrior;
  p--;
  nOld = (int)p[0];
  assert( mem.mutex!=0 );
  sqlite3_mutex_enter(mem.mutex);
  if( mem.nowUsed+nBytes-nOld>=mem.alarmThreshold ){
    sqlite3MemsysAlarm(nBytes-nOld);
  }
  if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
    p = 0;
  }else{
    p = realloc(p, nBytes+8);
    if( p==0 ){
      sqlite3MemsysAlarm(nBytes);
      p = pPrior;
      p--;
      p = realloc(p, nBytes+8);
    }
  }
  if( p ){
    p[0] = nBytes;
    p++;
    mem.nowUsed += nBytes-nOld;
    if( mem.nowUsed>mem.mxUsed ){
      mem.mxUsed = mem.nowUsed;
    }
  }
  sqlite3_mutex_leave(mem.mutex);
  return (void*)p;
}

#endif /* SQLITE_SYSTEM_MALLOC */

/************** End of mem1.c ************************************************/
/************** Begin file mem2.c ********************************************/
/*
** 2007 August 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement a memory
** allocation subsystem for use by SQLite.  
**
** $Id: mem2.c,v 1.26 2008/04/10 14:57:25 drh Exp $
*/

/*
** This version of the memory allocator is used only if the
** SQLITE_MEMDEBUG macro is defined
*/
#ifdef SQLITE_MEMDEBUG

/*
** The backtrace functionality is only available with GLIBC
*/
#ifdef __GLIBC__
  extern int backtrace(void**,int);
  extern void backtrace_symbols_fd(void*const*,int,int);
#else
# define backtrace(A,B) 0
# define backtrace_symbols_fd(A,B,C)
#endif

/*
** Each memory allocation looks like this:
**
**  ------------------------------------------------------------------------
**  | Title |  backtrace pointers |  MemBlockHdr |  allocation |  EndGuard |
**  ------------------------------------------------------------------------
**
** The application code sees only a pointer to the allocation.  We have
** to back up from the allocation pointer to find the MemBlockHdr.  The
** MemBlockHdr tells us the size of the allocation and the number of
** backtrace pointers.  There is also a guard word at the end of the
** MemBlockHdr.
*/
struct MemBlockHdr {
  i64 iSize;                          /* Size of this allocation */
  struct MemBlockHdr *pNext, *pPrev;  /* Linked list of all unfreed memory */
  char nBacktrace;                    /* Number of backtraces on this alloc */
  char nBacktraceSlots;               /* Available backtrace slots */
  short nTitle;                       /* Bytes of title; includes '\0' */
  int iForeGuard;                     /* Guard word for sanity */
};

/*
** Guard words
*/
#define FOREGUARD 0x80F5E153
#define REARGUARD 0xE4676B53

/*
** Number of malloc size increments to track.
*/
#define NCSIZE  1000

/*
** All of the static variables used by this module are collected
** into a single structure named "mem".  This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
static struct {
  /*
  ** The alarm callback and its arguments.  The mem.mutex lock will
  ** be held while the callback is running.  Recursive calls into
  ** the memory subsystem are allowed, but no new callbacks will be
  ** issued.  The alarmBusy variable is set to prevent recursive
  ** callbacks.
  */
  sqlite3_int64 alarmThreshold;
  void (*alarmCallback)(void*, sqlite3_int64, int);
  void *alarmArg;
  int alarmBusy;
  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;
  
  /*
  ** Current allocation and high-water mark.
  */
  sqlite3_int64 nowUsed;
  sqlite3_int64 mxUsed;
  
  /*
  ** Head and tail of a linked list of all outstanding allocations
  */
  struct MemBlockHdr *pFirst;
  struct MemBlockHdr *pLast;
  
  /*
  ** The number of levels of backtrace to save in new allocations.
  */
  int nBacktrace;
  void (*xBacktrace)(int, int, void **);

  /*
  ** Title text to insert in front of each block
  */
  int nTitle;        /* Bytes of zTitle to save.  Includes '\0' and padding */
  char zTitle[100];  /* The title text */

  /* 
  ** sqlite3MallocDisallow() increments the following counter.
  ** sqlite3MallocAllow() decrements it.
  */
  int disallow; /* Do not allow memory allocation */

  /*
  ** Gather statistics on the sizes of memory allocations.
  ** sizeCnt[i] is the number of allocation attempts of i*8
  ** bytes.  i==NCSIZE is the number of allocation attempts for
  ** sizes more than NCSIZE*8 bytes.
  */
  int sizeCnt[NCSIZE];

} mem;


/*
** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
*/
static void enterMem(void){
  if( mem.mutex==0 ){
    mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
  }
  sqlite3_mutex_enter(mem.mutex);
}

/*
** Return the amount of memory currently checked out.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
  sqlite3_int64 n;
  enterMem();
  n = mem.nowUsed;
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Return the maximum amount of memory that has ever been
** checked out since either the beginning of this process
** or since the most recent reset.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 n;
  enterMem();
  n = mem.mxUsed;
  if( resetFlag ){
    mem.mxUsed = mem.nowUsed;
  }
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Change the alarm callback
*/
SQLITE_API int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used, int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  enterMem();
  mem.alarmCallback = xCallback;
  mem.alarmArg = pArg;
  mem.alarmThreshold = iThreshold;
  sqlite3_mutex_leave(mem.mutex);
  return SQLITE_OK;
}

/*
** Trigger the alarm 
*/
static void sqlite3MemsysAlarm(int nByte){
  void (*xCallback)(void*,sqlite3_int64,int);
  sqlite3_int64 nowUsed;
  void *pArg;
  if( mem.alarmCallback==0 || mem.alarmBusy  ) return;
  mem.alarmBusy = 1;
  xCallback = mem.alarmCallback;
  nowUsed = mem.nowUsed;
  pArg = mem.alarmArg;
  sqlite3_mutex_leave(mem.mutex);
  xCallback(pArg, nowUsed, nByte);
  sqlite3_mutex_enter(mem.mutex);
  mem.alarmBusy = 0;
}

/*
** Given an allocation, find the MemBlockHdr for that allocation.
**
** This routine checks the guards at either end of the allocation and
** if they are incorrect it asserts.
*/
static struct MemBlockHdr *sqlite3MemsysGetHeader(void *pAllocation){
  struct MemBlockHdr *p;
  int *pInt;
  u8 *pU8;
  int nReserve;

  p = (struct MemBlockHdr*)pAllocation;
  p--;
  assert( p->iForeGuard==FOREGUARD );
  nReserve = (p->iSize+7)&~7;
  pInt = (int*)pAllocation;
  pU8 = (u8*)pAllocation;
  assert( pInt[nReserve/sizeof(int)]==REARGUARD );
  assert( (nReserve-0)<=p->iSize || pU8[nReserve-1]==0x65 );
  assert( (nReserve-1)<=p->iSize || pU8[nReserve-2]==0x65 );
  assert( (nReserve-2)<=p->iSize || pU8[nReserve-3]==0x65 );
  return p;
}

/*
** Return the number of bytes currently allocated at address p.
*/
SQLITE_PRIVATE int sqlite3MallocSize(void *p){
  struct MemBlockHdr *pHdr;
  if( !p ){
    return 0;
  }
  pHdr = sqlite3MemsysGetHeader(p);
  return pHdr->iSize;
}

/*
** Allocate nByte bytes of memory.
*/
SQLITE_API void *sqlite3_malloc(int nByte){
  struct MemBlockHdr *pHdr;
  void **pBt;
  char *z;
  int *pInt;
  void *p = 0;
  int totalSize;

  if( nByte>0 ){
    int nReserve;
    enterMem();
    assert( mem.disallow==0 );
    if( mem.alarmCallback!=0 && mem.nowUsed+nByte>=mem.alarmThreshold ){
      sqlite3MemsysAlarm(nByte);
    }
    nReserve = (nByte+7)&~7;
    if( nReserve/8>NCSIZE-1 ){
      mem.sizeCnt[NCSIZE-1]++;
    }else{
      mem.sizeCnt[nReserve/8]++;
    }
    totalSize = nReserve + sizeof(*pHdr) + sizeof(int) +
                 mem.nBacktrace*sizeof(void*) + mem.nTitle;
    if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
      p = 0;
    }else{
      p = malloc(totalSize);
      if( p==0 ){
        sqlite3MemsysAlarm(nByte);
        p = malloc(totalSize);
      }
    }
    if( p ){
      z = p;
      pBt = (void**)&z[mem.nTitle];
      pHdr = (struct MemBlockHdr*)&pBt[mem.nBacktrace];
      pHdr->pNext = 0;
      pHdr->pPrev = mem.pLast;
      if( mem.pLast ){
        mem.pLast->pNext = pHdr;
      }else{
        mem.pFirst = pHdr;
      }
      mem.pLast = pHdr;
      pHdr->iForeGuard = FOREGUARD;
      pHdr->nBacktraceSlots = mem.nBacktrace;
      pHdr->nTitle = mem.nTitle;
      if( mem.nBacktrace ){
        void *aAddr[40];
        pHdr->nBacktrace = backtrace(aAddr, mem.nBacktrace+1)-1;
        memcpy(pBt, &aAddr[1], pHdr->nBacktrace*sizeof(void*));
      if( mem.xBacktrace ){
          mem.xBacktrace(nByte, pHdr->nBacktrace-1, &aAddr[1]);
      }
      }else{
        pHdr->nBacktrace = 0;
      }
      if( mem.nTitle ){
        memcpy(z, mem.zTitle, mem.nTitle);
      }
      pHdr->iSize = nByte;
      pInt = (int*)&pHdr[1];
      pInt[nReserve/sizeof(int)] = REARGUARD;
      memset(pInt, 0x65, nReserve);
      mem.nowUsed += nByte;
      if( mem.nowUsed>mem.mxUsed ){
        mem.mxUsed = mem.nowUsed;
      }
      p = (void*)pInt;
    }
    sqlite3_mutex_leave(mem.mutex);
  }
  return p; 
}

/*
** Free memory.
*/
SQLITE_API void sqlite3_free(void *pPrior){
  struct MemBlockHdr *pHdr;
  void **pBt;
  char *z;
  if( pPrior==0 ){
    return;
  }
  assert( mem.mutex!=0 );
  pHdr = sqlite3MemsysGetHeader(pPrior);
  pBt = (void**)pHdr;
  pBt -= pHdr->nBacktraceSlots;
  sqlite3_mutex_enter(mem.mutex);
  mem.nowUsed -= pHdr->iSize;
  if( pHdr->pPrev ){
    assert( pHdr->pPrev->pNext==pHdr );
    pHdr->pPrev->pNext = pHdr->pNext;
  }else{
    assert( mem.pFirst==pHdr );
    mem.pFirst = pHdr->pNext;
  }
  if( pHdr->pNext ){
    assert( pHdr->pNext->pPrev==pHdr );
    pHdr->pNext->pPrev = pHdr->pPrev;
  }else{
    assert( mem.pLast==pHdr );
    mem.pLast = pHdr->pPrev;
  }
  z = (char*)pBt;
  z -= pHdr->nTitle;
  memset(z, 0x2b, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
                  pHdr->iSize + sizeof(int) + pHdr->nTitle);
  free(z);
  sqlite3_mutex_leave(mem.mutex);  
}

/*
** Change the size of an existing memory allocation.
**
** For this debugging implementation, we *always* make a copy of the
** allocation into a new place in memory.  In this way, if the 
** higher level code is using pointer to the old allocation, it is 
** much more likely to break and we are much more liking to find
** the error.
*/
SQLITE_API void *sqlite3_realloc(void *pPrior, int nByte){
  struct MemBlockHdr *pOldHdr;
  void *pNew;
  if( pPrior==0 ){
    return sqlite3_malloc(nByte);
  }
  if( nByte<=0 ){
    sqlite3_free(pPrior);
    return 0;
  }
  assert( mem.disallow==0 );
  pOldHdr = sqlite3MemsysGetHeader(pPrior);
  pNew = sqlite3_malloc(nByte);
  if( pNew ){
    memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
    if( nByte>pOldHdr->iSize ){
      memset(&((char*)pNew)[pOldHdr->iSize], 0x2b, nByte - pOldHdr->iSize);
    }
    sqlite3_free(pPrior);
  }
  return pNew;
}

/*
** Set the number of backtrace levels kept for each allocation.
** A value of zero turns of backtracing.  The number is always rounded
** up to a multiple of 2.
*/
SQLITE_PRIVATE void sqlite3MemdebugBacktrace(int depth){
  if( depth<0 ){ depth = 0; }
  if( depth>20 ){ depth = 20; }
  depth = (depth+1)&0xfe;
  mem.nBacktrace = depth;
}

SQLITE_PRIVATE void sqlite3MemdebugBacktraceCallback(void (*xBacktrace)(int, int, void **)){
  mem.xBacktrace = xBacktrace;
}

/*
** Set the title string for subsequent allocations.
*/
SQLITE_PRIVATE void sqlite3MemdebugSettitle(const char *zTitle){
  int n = strlen(zTitle) + 1;
  enterMem();
  if( n>=sizeof(mem.zTitle) ) n = sizeof(mem.zTitle)-1;
  memcpy(mem.zTitle, zTitle, n);
  mem.zTitle[n] = 0;
  mem.nTitle = (n+7)&~7;
  sqlite3_mutex_leave(mem.mutex);
}

SQLITE_PRIVATE void sqlite3MemdebugSync(){
  struct MemBlockHdr *pHdr;
  for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
    void **pBt = (void**)pHdr;
    pBt -= pHdr->nBacktraceSlots;
    mem.xBacktrace(pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);
  }
}

/*
** Open the file indicated and write a log of all unfreed memory 
** allocations into that log.
*/
SQLITE_PRIVATE void sqlite3MemdebugDump(const char *zFilename){
  FILE *out;
  struct MemBlockHdr *pHdr;
  void **pBt;
  int i;
  out = fopen(zFilename, "w");
  if( out==0 ){
    fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
                    zFilename);
    return;
  }
  for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
    char *z = (char*)pHdr;
    z -= pHdr->nBacktraceSlots*sizeof(void*) + pHdr->nTitle;
    fprintf(out, "**** %lld bytes at %p from %s ****\n", 
            pHdr->iSize, &pHdr[1], pHdr->nTitle ? z : "???");
    if( pHdr->nBacktrace ){
      fflush(out);
      pBt = (void**)pHdr;
      pBt -= pHdr->nBacktraceSlots;
      backtrace_symbols_fd(pBt, pHdr->nBacktrace, fileno(out));
      fprintf(out, "\n");
    }
  }
  fprintf(out, "COUNTS:\n");
  for(i=0; i<NCSIZE-1; i++){
    if( mem.sizeCnt[i] ){
      fprintf(out, "   %3d: %d\n", i*8+8, mem.sizeCnt[i]);
    }
  }
  if( mem.sizeCnt[NCSIZE-1] ){
    fprintf(out, "  >%3d: %d\n", NCSIZE*8, mem.sizeCnt[NCSIZE-1]);
  }
  fclose(out);
}

/*
** Return the number of times sqlite3_malloc() has been called.
*/
SQLITE_PRIVATE int sqlite3MemdebugMallocCount(){
  int i;
  int nTotal = 0;
  for(i=0; i<NCSIZE; i++){
    nTotal += mem.sizeCnt[i];
  }
  return nTotal;
}


#endif /* SQLITE_MEMDEBUG */

/************** End of mem2.c ************************************************/
/************** Begin file mem3.c ********************************************/
/*
** 2007 October 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement a memory
** allocation subsystem for use by SQLite. 
**
** This version of the memory allocation subsystem omits all
** use of malloc().  All dynamically allocatable memory is
** contained in a static array, mem.aPool[].  The size of this
** fixed memory pool is SQLITE_MEMORY_SIZE bytes.
**
** This version of the memory allocation subsystem is used if
** and only if SQLITE_MEMORY_SIZE is defined.
**
** $Id: mem3.c,v 1.12 2008/02/19 15:15:16 drh Exp $
*/

/*
** This version of the memory allocator is used only when 
** SQLITE_MEMORY_SIZE is defined.
*/
#ifdef SQLITE_MEMORY_SIZE

/*
** Maximum size (in Mem3Blocks) of a "small" chunk.
*/
#define MX_SMALL 10


/*
** Number of freelist hash slots
*/
#define N_HASH  61

/*
** A memory allocation (also called a "chunk") consists of two or 
** more blocks where each block is 8 bytes.  The first 8 bytes are 
** a header that is not returned to the user.
**
** A chunk is two or more blocks that is either checked out or
** free.  The first block has format u.hdr.  u.hdr.size4x is 4 times the
** size of the allocation in blocks if the allocation is free.
** The u.hdr.size4x&1 bit is true if the chunk is checked out and
** false if the chunk is on the freelist.  The u.hdr.size4x&2 bit
** is true if the previous chunk is checked out and false if the
** previous chunk is free.  The u.hdr.prevSize field is the size of
** the previous chunk in blocks if the previous chunk is on the
** freelist. If the previous chunk is checked out, then
** u.hdr.prevSize can be part of the data for that chunk and should
** not be read or written.
**
** We often identify a chunk by its index in mem.aPool[].  When
** this is done, the chunk index refers to the second block of
** the chunk.  In this way, the first chunk has an index of 1.
** A chunk index of 0 means "no such chunk" and is the equivalent
** of a NULL pointer.
**
** The second block of free chunks is of the form u.list.  The
** two fields form a double-linked list of chunks of related sizes.
** Pointers to the head of the list are stored in mem.aiSmall[] 
** for smaller chunks and mem.aiHash[] for larger chunks.
**
** The second block of a chunk is user data if the chunk is checked 
** out.  If a chunk is checked out, the user data may extend into
** the u.hdr.prevSize value of the following chunk.
*/
typedef struct Mem3Block Mem3Block;
struct Mem3Block {
  union {
    struct {
      u32 prevSize;   /* Size of previous chunk in Mem3Block elements */
      u32 size4x;     /* 4x the size of current chunk in Mem3Block elements */
    } hdr;
    struct {
      u32 next;       /* Index in mem.aPool[] of next free chunk */
      u32 prev;       /* Index in mem.aPool[] of previous free chunk */
    } list;
  } u;
};

/*
** All of the static variables used by this module are collected
** into a single structure named "mem".  This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
static struct {
  /*
  ** True if we are evaluating an out-of-memory callback.
  */
  int alarmBusy;
  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;
  
  /*
  ** The minimum amount of free space that we have seen.
  */
  u32 mnMaster;

  /*
  ** iMaster is the index of the master chunk.  Most new allocations
  ** occur off of this chunk.  szMaster is the size (in Mem3Blocks)
  ** of the current master.  iMaster is 0 if there is not master chunk.
  ** The master chunk is not in either the aiHash[] or aiSmall[].
  */
  u32 iMaster;
  u32 szMaster;

  /*
  ** Array of lists of free blocks according to the block size 
  ** for smaller chunks, or a hash on the block size for larger
  ** chunks.
  */
  u32 aiSmall[MX_SMALL-1];   /* For sizes 2 through MX_SMALL, inclusive */
  u32 aiHash[N_HASH];        /* For sizes MX_SMALL+1 and larger */

  /*
  ** Memory available for allocation
  */
  Mem3Block aPool[SQLITE_MEMORY_SIZE/sizeof(Mem3Block)+2];
} mem;

/*
** Unlink the chunk at mem.aPool[i] from list it is currently
** on.  *pRoot is the list that i is a member of.
*/
static void memsys3UnlinkFromList(u32 i, u32 *pRoot){
  u32 next = mem.aPool[i].u.list.next;
  u32 prev = mem.aPool[i].u.list.prev;
  assert( sqlite3_mutex_held(mem.mutex) );
  if( prev==0 ){
    *pRoot = next;
  }else{
    mem.aPool[prev].u.list.next = next;
  }
  if( next ){
    mem.aPool[next].u.list.prev = prev;
  }
  mem.aPool[i].u.list.next = 0;
  mem.aPool[i].u.list.prev = 0;
}

/*
** Unlink the chunk at index i from 
** whatever list is currently a member of.
*/
static void memsys3Unlink(u32 i){
  u32 size, hash;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
  assert( i>=1 );
  size = mem.aPool[i-1].u.hdr.size4x/4;
  assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
  assert( size>=2 );
  if( size <= MX_SMALL ){
    memsys3UnlinkFromList(i, &mem.aiSmall[size-2]);
  }else{
    hash = size % N_HASH;
    memsys3UnlinkFromList(i, &mem.aiHash[hash]);
  }
}

/*
** Link the chunk at mem.aPool[i] so that is on the list rooted
** at *pRoot.
*/
static void memsys3LinkIntoList(u32 i, u32 *pRoot){
  assert( sqlite3_mutex_held(mem.mutex) );
  mem.aPool[i].u.list.next = *pRoot;
  mem.aPool[i].u.list.prev = 0;
  if( *pRoot ){
    mem.aPool[*pRoot].u.list.prev = i;
  }
  *pRoot = i;
}

/*
** Link the chunk at index i into either the appropriate
** small chunk list, or into the large chunk hash table.
*/
static void memsys3Link(u32 i){
  u32 size, hash;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( i>=1 );
  assert( (mem.aPool[i-1].u.hdr.size4x & 1)==0 );
  size = mem.aPool[i-1].u.hdr.size4x/4;
  assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
  assert( size>=2 );
  if( size <= MX_SMALL ){
    memsys3LinkIntoList(i, &mem.aiSmall[size-2]);
  }else{
    hash = size % N_HASH;
    memsys3LinkIntoList(i, &mem.aiHash[hash]);
  }
}

/*
** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
**
** Also:  Initialize the memory allocation subsystem the first time
** this routine is called.
*/
static void memsys3Enter(void){
  if( mem.mutex==0 ){
    mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
    mem.aPool[0].u.hdr.size4x = SQLITE_MEMORY_SIZE/2 + 2;
    mem.aPool[SQLITE_MEMORY_SIZE/8].u.hdr.prevSize = SQLITE_MEMORY_SIZE/8;
    mem.aPool[SQLITE_MEMORY_SIZE/8].u.hdr.size4x = 1;
    mem.iMaster = 1;
    mem.szMaster = SQLITE_MEMORY_SIZE/8;
    mem.mnMaster = mem.szMaster;
  }
  sqlite3_mutex_enter(mem.mutex);
}

/*
** Return the amount of memory currently checked out.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
  sqlite3_int64 n;
  memsys3Enter();
  n = SQLITE_MEMORY_SIZE - mem.szMaster*8;
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Return the maximum amount of memory that has ever been
** checked out since either the beginning of this process
** or since the most recent reset.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 n;
  memsys3Enter();
  n = SQLITE_MEMORY_SIZE - mem.mnMaster*8;
  if( resetFlag ){
    mem.mnMaster = mem.szMaster;
  }
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}

/*
** Change the alarm callback.
**
** This is a no-op for the static memory allocator.  The purpose
** of the memory alarm is to support sqlite3_soft_heap_limit().
** But with this memory allocator, the soft_heap_limit is really
** a hard limit that is fixed at SQLITE_MEMORY_SIZE.
*/
SQLITE_API int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  return SQLITE_OK;
}

/*
** Called when we are unable to satisfy an allocation of nBytes.
*/
static void memsys3OutOfMemory(int nByte){
  if( !mem.alarmBusy ){
    mem.alarmBusy = 1;
    assert( sqlite3_mutex_held(mem.mutex) );
    sqlite3_mutex_leave(mem.mutex);
    sqlite3_release_memory(nByte);
    sqlite3_mutex_enter(mem.mutex);
    mem.alarmBusy = 0;
  }
}

/*
** Return the size of an outstanding allocation, in bytes.  The
** size returned omits the 8-byte header overhead.  This only
** works for chunks that are currently checked out.
*/
SQLITE_PRIVATE int sqlite3MallocSize(void *p){
  int iSize = 0;
  if( p ){
    Mem3Block *pBlock = (Mem3Block*)p;
    assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
    iSize = (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
  }
  return iSize;
}

/*
** Chunk i is a free chunk that has been unlinked.  Adjust its 
** size parameters for check-out and return a pointer to the 
** user portion of the chunk.
*/
static void *memsys3Checkout(u32 i, int nBlock){
  u32 x;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( i>=1 );
  assert( mem.aPool[i-1].u.hdr.size4x/4==nBlock );
  assert( mem.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
  x = mem.aPool[i-1].u.hdr.size4x;
  mem.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
  mem.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
  mem.aPool[i+nBlock-1].u.hdr.size4x |= 2;
  return &mem.aPool[i];
}

/*
** Carve a piece off of the end of the mem.iMaster free chunk.
** Return a pointer to the new allocation.  Or, if the master chunk
** is not large enough, return 0.
*/
static void *memsys3FromMaster(int nBlock){
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( mem.szMaster>=nBlock );
  if( nBlock>=mem.szMaster-1 ){
    /* Use the entire master */
    void *p = memsys3Checkout(mem.iMaster, mem.szMaster);
    mem.iMaster = 0;
    mem.szMaster = 0;
    mem.mnMaster = 0;
    return p;
  }else{
    /* Split the master block.  Return the tail. */
    u32 newi, x;
    newi = mem.iMaster + mem.szMaster - nBlock;
    assert( newi > mem.iMaster+1 );
    mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = nBlock;
    mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x |= 2;
    mem.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
    mem.szMaster -= nBlock;
    mem.aPool[newi-1].u.hdr.prevSize = mem.szMaster;
    x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
    mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
    if( mem.szMaster < mem.mnMaster ){
      mem.mnMaster = mem.szMaster;
    }
    return (void*)&mem.aPool[newi];
  }
}

/*
** *pRoot is the head of a list of free chunks of the same size
** or same size hash.  In other words, *pRoot is an entry in either
** mem.aiSmall[] or mem.aiHash[].  
**
** This routine examines all entries on the given list and tries
** to coalesce each entries with adjacent free chunks.  
**
** If it sees a chunk that is larger than mem.iMaster, it replaces 
** the current mem.iMaster with the new larger chunk.  In order for
** this mem.iMaster replacement to work, the master chunk must be
** linked into the hash tables.  That is not the normal state of
** affairs, of course.  The calling routine must link the master
** chunk before invoking this routine, then must unlink the (possibly
** changed) master chunk once this routine has finished.
*/
static void memsys3Merge(u32 *pRoot){
  u32 iNext, prev, size, i, x;

  assert( sqlite3_mutex_held(mem.mutex) );
  for(i=*pRoot; i>0; i=iNext){
    iNext = mem.aPool[i].u.list.next;
    size = mem.aPool[i-1].u.hdr.size4x;
    assert( (size&1)==0 );
    if( (size&2)==0 ){
      memsys3UnlinkFromList(i, pRoot);
      assert( i > mem.aPool[i-1].u.hdr.prevSize );
      prev = i - mem.aPool[i-1].u.hdr.prevSize;
      if( prev==iNext ){
        iNext = mem.aPool[prev].u.list.next;
      }
      memsys3Unlink(prev);
      size = i + size/4 - prev;
      x = mem.aPool[prev-1].u.hdr.size4x & 2;
      mem.aPool[prev-1].u.hdr.size4x = size*4 | x;
      mem.aPool[prev+size-1].u.hdr.prevSize = size;
      memsys3Link(prev);
      i = prev;
    }else{
      size /= 4;
    }
    if( size>mem.szMaster ){
      mem.iMaster = i;
      mem.szMaster = size;
    }
  }
}

/*
** Return a block of memory of at least nBytes in size.
** Return NULL if unable.
*/
static void *memsys3Malloc(int nByte){
  u32 i;
  int nBlock;
  int toFree;

  assert( sqlite3_mutex_held(mem.mutex) );
  assert( sizeof(Mem3Block)==8 );
  if( nByte<=12 ){
    nBlock = 2;
  }else{
    nBlock = (nByte + 11)/8;
  }
  assert( nBlock >= 2 );

  /* STEP 1:
  ** Look for an entry of the correct size in either the small
  ** chunk table or in the large chunk hash table.  This is
  ** successful most of the time (about 9 times out of 10).
  */
  if( nBlock <= MX_SMALL ){
    i = mem.aiSmall[nBlock-2];
    if( i>0 ){
      memsys3UnlinkFromList(i, &mem.aiSmall[nBlock-2]);
      return memsys3Checkout(i, nBlock);
    }
  }else{
    int hash = nBlock % N_HASH;
    for(i=mem.aiHash[hash]; i>0; i=mem.aPool[i].u.list.next){
      if( mem.aPool[i-1].u.hdr.size4x/4==nBlock ){
        memsys3UnlinkFromList(i, &mem.aiHash[hash]);
        return memsys3Checkout(i, nBlock);
      }
    }
  }

  /* STEP 2:
  ** Try to satisfy the allocation by carving a piece off of the end
  ** of the master chunk.  This step usually works if step 1 fails.
  */
  if( mem.szMaster>=nBlock ){
    return memsys3FromMaster(nBlock);
  }


  /* STEP 3:  
  ** Loop through the entire memory pool.  Coalesce adjacent free
  ** chunks.  Recompute the master chunk as the largest free chunk.
  ** Then try again to satisfy the allocation by carving a piece off
  ** of the end of the master chunk.  This step happens very
  ** rarely (we hope!)
  */
  for(toFree=nBlock*16; toFree<SQLITE_MEMORY_SIZE*2; toFree *= 2){
    memsys3OutOfMemory(toFree);
    if( mem.iMaster ){
      memsys3Link(mem.iMaster);
      mem.iMaster = 0;
      mem.szMaster = 0;
    }
    for(i=0; i<N_HASH; i++){
      memsys3Merge(&mem.aiHash[i]);
    }
    for(i=0; i<MX_SMALL-1; i++){
      memsys3Merge(&mem.aiSmall[i]);
    }
    if( mem.szMaster ){
      memsys3Unlink(mem.iMaster);
      if( mem.szMaster>=nBlock ){
        return memsys3FromMaster(nBlock);
      }
    }
  }

  /* If none of the above worked, then we fail. */
  return 0;
}

/*
** Free an outstanding memory allocation.
*/
void memsys3Free(void *pOld){
  Mem3Block *p = (Mem3Block*)pOld;
  int i;
  u32 size, x;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( p>mem.aPool && p<&mem.aPool[SQLITE_MEMORY_SIZE/8] );
  i = p - mem.aPool;
  assert( (mem.aPool[i-1].u.hdr.size4x&1)==1 );
  size = mem.aPool[i-1].u.hdr.size4x/4;
  assert( i+size<=SQLITE_MEMORY_SIZE/8+1 );
  mem.aPool[i-1].u.hdr.size4x &= ~1;
  mem.aPool[i+size-1].u.hdr.prevSize = size;
  mem.aPool[i+size-1].u.hdr.size4x &= ~2;
  memsys3Link(i);

  /* Try to expand the master using the newly freed chunk */
  if( mem.iMaster ){
    while( (mem.aPool[mem.iMaster-1].u.hdr.size4x&2)==0 ){
      size = mem.aPool[mem.iMaster-1].u.hdr.prevSize;
      mem.iMaster -= size;
      mem.szMaster += size;
      memsys3Unlink(mem.iMaster);
      x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
      mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
      mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = mem.szMaster;
    }
    x = mem.aPool[mem.iMaster-1].u.hdr.size4x & 2;
    while( (mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x&1)==0 ){
      memsys3Unlink(mem.iMaster+mem.szMaster);
      mem.szMaster += mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.size4x/4;
      mem.aPool[mem.iMaster-1].u.hdr.size4x = mem.szMaster*4 | x;
      mem.aPool[mem.iMaster+mem.szMaster-1].u.hdr.prevSize = mem.szMaster;
    }
  }
}

/*
** Allocate nBytes of memory
*/
SQLITE_API void *sqlite3_malloc(int nBytes){
  sqlite3_int64 *p = 0;
  if( nBytes>0 ){
    memsys3Enter();
    p = memsys3Malloc(nBytes);
    sqlite3_mutex_leave(mem.mutex);
  }
  return (void*)p; 
}

/*
** Free memory.
*/
SQLITE_API void sqlite3_free(void *pPrior){
  if( pPrior==0 ){
    return;
  }
  assert( mem.mutex!=0 );
  sqlite3_mutex_enter(mem.mutex);
  memsys3Free(pPrior);
  sqlite3_mutex_leave(mem.mutex);  
}

/*
** Change the size of an existing memory allocation
*/
SQLITE_API void *sqlite3_realloc(void *pPrior, int nBytes){
  int nOld;
  void *p;
  if( pPrior==0 ){
    return sqlite3_malloc(nBytes);
  }
  if( nBytes<=0 ){
    sqlite3_free(pPrior);
    return 0;
  }
  assert( mem.mutex!=0 );
  nOld = sqlite3MallocSize(pPrior);
  if( nBytes<=nOld && nBytes>=nOld-128 ){
    return pPrior;
  }
  sqlite3_mutex_enter(mem.mutex);
  p = memsys3Malloc(nBytes);
  if( p ){
    if( nOld<nBytes ){
      memcpy(p, pPrior, nOld);
    }else{
      memcpy(p, pPrior, nBytes);
    }
    memsys3Free(pPrior);
  }
  sqlite3_mutex_leave(mem.mutex);
  return p;
}

/*
** Open the file indicated and write a log of all unfreed memory 
** allocations into that log.
*/
SQLITE_PRIVATE void sqlite3MemdebugDump(const char *zFilename){
#ifdef SQLITE_DEBUG
  FILE *out;
  int i, j;
  u32 size;
  if( zFilename==0 || zFilename[0]==0 ){
    out = stdout;
  }else{
    out = fopen(zFilename, "w");
    if( out==0 ){
      fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
                      zFilename);
      return;
    }
  }
  memsys3Enter();
  fprintf(out, "CHUNKS:\n");
  for(i=1; i<=SQLITE_MEMORY_SIZE/8; i+=size/4){
    size = mem.aPool[i-1].u.hdr.size4x;
    if( size/4<=1 ){
      fprintf(out, "%p size error\n", &mem.aPool[i]);
      assert( 0 );
      break;
    }
    if( (size&1)==0 && mem.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){
      fprintf(out, "%p tail size does not match\n", &mem.aPool[i]);
      assert( 0 );
      break;
    }
    if( ((mem.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){
      fprintf(out, "%p tail checkout bit is incorrect\n", &mem.aPool[i]);
      assert( 0 );
      break;
    }
    if( size&1 ){
      fprintf(out, "%p %6d bytes checked out\n", &mem.aPool[i], (size/4)*8-8);
    }else{
      fprintf(out, "%p %6d bytes free%s\n", &mem.aPool[i], (size/4)*8-8,
                  i==mem.iMaster ? " **master**" : "");
    }
  }
  for(i=0; i<MX_SMALL-1; i++){
    if( mem.aiSmall[i]==0 ) continue;
    fprintf(out, "small(%2d):", i);
    for(j = mem.aiSmall[i]; j>0; j=mem.aPool[j].u.list.next){
      fprintf(out, " %p(%d)", &mem.aPool[j],
              (mem.aPool[j-1].u.hdr.size4x/4)*8-8);
    }
    fprintf(out, "\n"); 
  }
  for(i=0; i<N_HASH; i++){
    if( mem.aiHash[i]==0 ) continue;
    fprintf(out, "hash(%2d):", i);
    for(j = mem.aiHash[i]; j>0; j=mem.aPool[j].u.list.next){
      fprintf(out, " %p(%d)", &mem.aPool[j],
              (mem.aPool[j-1].u.hdr.size4x/4)*8-8);
    }
    fprintf(out, "\n"); 
  }
  fprintf(out, "master=%d\n", mem.iMaster);
  fprintf(out, "nowUsed=%d\n", SQLITE_MEMORY_SIZE - mem.szMaster*8);
  fprintf(out, "mxUsed=%d\n", SQLITE_MEMORY_SIZE - mem.mnMaster*8);
  sqlite3_mutex_leave(mem.mutex);
  if( out==stdout ){
    fflush(stdout);
  }else{
    fclose(out);
  }
#endif
}


#endif /* !SQLITE_MEMORY_SIZE */

/************** End of mem3.c ************************************************/
/************** Begin file mem5.c ********************************************/
/*
** 2007 October 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement a memory
** allocation subsystem for use by SQLite. 
**
** This version of the memory allocation subsystem omits all
** use of malloc().  All dynamically allocatable memory is
** contained in a static array, mem.aPool[].  The size of this
** fixed memory pool is SQLITE_POW2_MEMORY_SIZE bytes.
**
** This version of the memory allocation subsystem is used if
** and only if SQLITE_POW2_MEMORY_SIZE is defined.
**
** $Id: mem5.c,v 1.4 2008/02/19 15:15:16 drh Exp $
*/

/*
** This version of the memory allocator is used only when 
** SQLITE_POW2_MEMORY_SIZE is defined.
*/
#ifdef SQLITE_POW2_MEMORY_SIZE

/*
** Log2 of the minimum size of an allocation.  For example, if
** 4 then all allocations will be rounded up to at least 16 bytes.
** If 5 then all allocations will be rounded up to at least 32 bytes.
*/
#ifndef SQLITE_POW2_LOGMIN
# define SQLITE_POW2_LOGMIN 6
#endif
#define POW2_MIN (1<<SQLITE_POW2_LOGMIN)

/*
** Log2 of the maximum size of an allocation.
*/
#ifndef SQLITE_POW2_LOGMAX
# define SQLITE_POW2_LOGMAX 18
#endif
#define POW2_MAX (((unsigned int)1)<<SQLITE_POW2_LOGMAX)

/*
** Number of distinct allocation sizes.
*/
#define NSIZE (SQLITE_POW2_LOGMAX - SQLITE_POW2_LOGMIN + 1)

/*
** A minimum allocation is an instance of the following structure.
** Larger allocations are an array of these structures where the
** size of the array is a power of 2.
*/
typedef struct Mem5Block Mem5Block;
struct Mem5Block {
  union {
    char aData[POW2_MIN];
    struct {
      int next;       /* Index in mem.aPool[] of next free chunk */
      int prev;       /* Index in mem.aPool[] of previous free chunk */
    } list;
  } u;
};

/*
** Number of blocks of memory available for allocation.
*/
#define NBLOCK (SQLITE_POW2_MEMORY_SIZE/POW2_MIN)

/*
** The size in blocks of an POW2_MAX allocation
*/
#define SZ_MAX (1<<(NSIZE-1))

/*
** Masks used for mem.aCtrl[] elements.
*/
#define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block relative to POW2_MIN */
#define CTRL_FREE     0x20    /* True if not checked out */

/*
** All of the static variables used by this module are collected
** into a single structure named "mem".  This is to keep the
** static variables organized and to reduce namespace pollution
** when this module is combined with other in the amalgamation.
*/
static struct {
  /*
  ** The alarm callback and its arguments.  The mem.mutex lock will
  ** be held while the callback is running.  Recursive calls into
  ** the memory subsystem are allowed, but no new callbacks will be
  ** issued.  The alarmBusy variable is set to prevent recursive
  ** callbacks.
  */
  sqlite3_int64 alarmThreshold;
  void (*alarmCallback)(void*, sqlite3_int64,int);
  void *alarmArg;
  int alarmBusy;
  
  /*
  ** Mutex to control access to the memory allocation subsystem.
  */
  sqlite3_mutex *mutex;

  /*
  ** Performance statistics
  */
  u64 nAlloc;         /* Total number of calls to malloc */
  u64 totalAlloc;     /* Total of all malloc calls - includes internal frag */
  u64 totalExcess;    /* Total internal fragmentation */
  u32 currentOut;     /* Current checkout, including internal fragmentation */
  u32 currentCount;   /* Current number of distinct checkouts */
  u32 maxOut;         /* Maximum instantaneous currentOut */
  u32 maxCount;       /* Maximum instantaneous currentCount */
  u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */
  
  /*
  ** Lists of free blocks of various sizes.
  */
  int aiFreelist[NSIZE];

  /*
  ** Space for tracking which blocks are checked out and the size
  ** of each block.  One byte per block.
  */
  u8 aCtrl[NBLOCK];

  /*
  ** Memory available for allocation
  */
  Mem5Block aPool[NBLOCK];
} mem;

/*
** Unlink the chunk at mem.aPool[i] from list it is currently
** on.  It should be found on mem.aiFreelist[iLogsize].
*/
static void memsys5Unlink(int i, int iLogsize){
  int next, prev;
  assert( i>=0 && i<NBLOCK );
  assert( iLogsize>=0 && iLogsize<NSIZE );
  assert( (mem.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
  assert( sqlite3_mutex_held(mem.mutex) );

  next = mem.aPool[i].u.list.next;
  prev = mem.aPool[i].u.list.prev;
  if( prev<0 ){
    mem.aiFreelist[iLogsize] = next;
  }else{
    mem.aPool[prev].u.list.next = next;
  }
  if( next>=0 ){
    mem.aPool[next].u.list.prev = prev;
  }
}

/*
** Link the chunk at mem.aPool[i] so that is on the iLogsize
** free list.
*/
static void memsys5Link(int i, int iLogsize){
  int x;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( i>=0 && i<NBLOCK );
  assert( iLogsize>=0 && iLogsize<NSIZE );
  assert( (mem.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );

  mem.aPool[i].u.list.next = x = mem.aiFreelist[iLogsize];
  mem.aPool[i].u.list.prev = -1;
  if( x>=0 ){
    assert( x<NBLOCK );
    mem.aPool[x].u.list.prev = i;
  }
  mem.aiFreelist[iLogsize] = i;
}

/*
** Enter the mutex mem.mutex. Allocate it if it is not already allocated.
**
** Also:  Initialize the memory allocation subsystem the first time
** this routine is called.
*/
static void memsys5Enter(void){
  if( mem.mutex==0 ){
    int i;
    assert( sizeof(Mem5Block)==POW2_MIN );
    assert( (SQLITE_POW2_MEMORY_SIZE % POW2_MAX)==0 );
    assert( SQLITE_POW2_MEMORY_SIZE>=POW2_MAX );
    mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM);
    sqlite3_mutex_enter(mem.mutex);
    for(i=0; i<NSIZE; i++) mem.aiFreelist[i] = -1;
    for(i=0; i<=NBLOCK-SZ_MAX; i += SZ_MAX){
      mem.aCtrl[i] = (NSIZE-1) | CTRL_FREE;
      memsys5Link(i, NSIZE-1);
    }
  }else{
    sqlite3_mutex_enter(mem.mutex);
  }
}

/*
** Return the amount of memory currently checked out.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
  return mem.currentOut;
}

/*
** Return the maximum amount of memory that has ever been
** checked out since either the beginning of this process
** or since the most recent reset.
*/
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 n;
  memsys5Enter();
  n = mem.maxOut;
  if( resetFlag ){
    mem.maxOut = mem.currentOut;
  }
  sqlite3_mutex_leave(mem.mutex);  
  return n;
}


/*
** Trigger the alarm 
*/
static void memsys5Alarm(int nByte){
  void (*xCallback)(void*,sqlite3_int64,int);
  sqlite3_int64 nowUsed;
  void *pArg;
  if( mem.alarmCallback==0 || mem.alarmBusy  ) return;
  mem.alarmBusy = 1;
  xCallback = mem.alarmCallback;
  nowUsed = mem.currentOut;
  pArg = mem.alarmArg;
  sqlite3_mutex_leave(mem.mutex);
  xCallback(pArg, nowUsed, nByte);
  sqlite3_mutex_enter(mem.mutex);
  mem.alarmBusy = 0;
}

/*
** Change the alarm callback.
**
** This is a no-op for the static memory allocator.  The purpose
** of the memory alarm is to support sqlite3_soft_heap_limit().
** But with this memory allocator, the soft_heap_limit is really
** a hard limit that is fixed at SQLITE_POW2_MEMORY_SIZE.
*/
SQLITE_API int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  memsys5Enter();
  mem.alarmCallback = xCallback;
  mem.alarmArg = pArg;
  mem.alarmThreshold = iThreshold;
  sqlite3_mutex_leave(mem.mutex);
  return SQLITE_OK;
}

/*
** Return the size of an outstanding allocation, in bytes.  The
** size returned omits the 8-byte header overhead.  This only
** works for chunks that are currently checked out.
*/
SQLITE_PRIVATE int sqlite3MallocSize(void *p){
  int iSize = 0;
  if( p ){
    int i = ((Mem5Block*)p) - mem.aPool;
    assert( i>=0 && i<NBLOCK );
    iSize = 1 << ((mem.aCtrl[i]&CTRL_LOGSIZE) + SQLITE_POW2_LOGMIN);
  }
  return iSize;
}

/*
** Find the first entry on the freelist iLogsize.  Unlink that
** entry and return its index. 
*/
static int memsys5UnlinkFirst(int iLogsize){
  int i;
  int iFirst;

  assert( iLogsize>=0 && iLogsize<NSIZE );
  i = iFirst = mem.aiFreelist[iLogsize];
  assert( iFirst>=0 );
  while( i>0 ){
    if( i<iFirst ) iFirst = i;
    i = mem.aPool[i].u.list.next;
  }
  memsys5Unlink(iFirst, iLogsize);
  return iFirst;
}

/*
** Return a block of memory of at least nBytes in size.
** Return NULL if unable.
*/
static void *memsys5Malloc(int nByte){
  int i;           /* Index of a mem.aPool[] slot */
  int iBin;        /* Index into mem.aiFreelist[] */
  int iFullSz;     /* Size of allocation rounded up to power of 2 */
  int iLogsize;    /* Log2 of iFullSz/POW2_MIN */

  assert( sqlite3_mutex_held(mem.mutex) );

  /* Keep track of the maximum allocation request.  Even unfulfilled
  ** requests are counted */
  if( nByte>mem.maxRequest ){
    mem.maxRequest = nByte;
  }

  /* Simulate a memory allocation fault */
  if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ) return 0;

  /* Round nByte up to the next valid power of two */
  if( nByte>POW2_MAX ) return 0;
  for(iFullSz=POW2_MIN, iLogsize=0; iFullSz<nByte; iFullSz *= 2, iLogsize++){}

  /* If we will be over the memory alarm threshold after this allocation,
  ** then trigger the memory overflow alarm */
  if( mem.alarmCallback!=0 && mem.currentOut+iFullSz>=mem.alarmThreshold ){
    memsys5Alarm(iFullSz);
  }

  /* Make sure mem.aiFreelist[iLogsize] contains at least one free
  ** block.  If not, then split a block of the next larger power of
  ** two in order to create a new free block of size iLogsize.
  */
  for(iBin=iLogsize; mem.aiFreelist[iBin]<0 && iBin<NSIZE; iBin++){}
  if( iBin>=NSIZE ) return 0;
  i = memsys5UnlinkFirst(iBin);
  while( iBin>iLogsize ){
    int newSize;

    iBin--;
    newSize = 1 << iBin;
    mem.aCtrl[i+newSize] = CTRL_FREE | iBin;
    memsys5Link(i+newSize, iBin);
  }
  mem.aCtrl[i] = iLogsize;

  /* Update allocator performance statistics. */
  mem.nAlloc++;
  mem.totalAlloc += iFullSz;
  mem.totalExcess += iFullSz - nByte;
  mem.currentCount++;
  mem.currentOut += iFullSz;
  if( mem.maxCount<mem.currentCount ) mem.maxCount = mem.currentCount;
  if( mem.maxOut<mem.currentOut ) mem.maxOut = mem.currentOut;

  /* Return a pointer to the allocated memory. */
  return (void*)&mem.aPool[i];
}

/*
** Free an outstanding memory allocation.
*/
void memsys5Free(void *pOld){
  u32 size, iLogsize;
  int i;

  i = ((Mem5Block*)pOld) - mem.aPool;
  assert( sqlite3_mutex_held(mem.mutex) );
  assert( i>=0 && i<NBLOCK );
  assert( (mem.aCtrl[i] & CTRL_FREE)==0 );
  iLogsize = mem.aCtrl[i] & CTRL_LOGSIZE;
  size = 1<<iLogsize;
  assert( i+size-1<NBLOCK );
  mem.aCtrl[i] |= CTRL_FREE;
  mem.aCtrl[i+size-1] |= CTRL_FREE;
  assert( mem.currentCount>0 );
  assert( mem.currentOut>=0 );
  mem.currentCount--;
  mem.currentOut -= size*POW2_MIN;
  assert( mem.currentOut>0 || mem.currentCount==0 );
  assert( mem.currentCount>0 || mem.currentOut==0 );

  mem.aCtrl[i] = CTRL_FREE | iLogsize;
  while( iLogsize<NSIZE-1 ){
    int iBuddy;

    if( (i>>iLogsize) & 1 ){
      iBuddy = i - size;
    }else{
      iBuddy = i + size;
    }
    assert( iBuddy>=0 && iBuddy<NBLOCK );
    if( mem.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
    memsys5Unlink(iBuddy, iLogsize);
    iLogsize++;
    if( iBuddy<i ){
      mem.aCtrl[iBuddy] = CTRL_FREE | iLogsize;
      mem.aCtrl[i] = 0;
      i = iBuddy;
    }else{
      mem.aCtrl[i] = CTRL_FREE | iLogsize;
      mem.aCtrl[iBuddy] = 0;
    }
    size *= 2;
  }
  memsys5Link(i, iLogsize);
}

/*
** Allocate nBytes of memory
*/
SQLITE_API void *sqlite3_malloc(int nBytes){
  sqlite3_int64 *p = 0;
  if( nBytes>0 ){
    memsys5Enter();
    p = memsys5Malloc(nBytes);
    sqlite3_mutex_leave(mem.mutex);
  }
  return (void*)p; 
}

/*
** Free memory.
*/
SQLITE_API void sqlite3_free(void *pPrior){
  if( pPrior==0 ){
    return;
  }
  assert( mem.mutex!=0 );
  sqlite3_mutex_enter(mem.mutex);
  memsys5Free(pPrior);
  sqlite3_mutex_leave(mem.mutex);  
}

/*
** Change the size of an existing memory allocation
*/
SQLITE_API void *sqlite3_realloc(void *pPrior, int nBytes){
  int nOld;
  void *p;
  if( pPrior==0 ){
    return sqlite3_malloc(nBytes);
  }
  if( nBytes<=0 ){
    sqlite3_free(pPrior);
    return 0;
  }
  assert( mem.mutex!=0 );
  nOld = sqlite3MallocSize(pPrior);
  if( nBytes<=nOld ){
    return pPrior;
  }
  sqlite3_mutex_enter(mem.mutex);
  p = memsys5Malloc(nBytes);
  if( p ){
    memcpy(p, pPrior, nOld);
    memsys5Free(pPrior);
  }
  sqlite3_mutex_leave(mem.mutex);
  return p;
}

/*
** Open the file indicated and write a log of all unfreed memory 
** allocations into that log.
*/
SQLITE_PRIVATE void sqlite3MemdebugDump(const char *zFilename){
#ifdef SQLITE_DEBUG
  FILE *out;
  int i, j, n;

  if( zFilename==0 || zFilename[0]==0 ){
    out = stdout;
  }else{
    out = fopen(zFilename, "w");
    if( out==0 ){
      fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
                      zFilename);
      return;
    }
  }
  memsys5Enter();
  for(i=0; i<NSIZE; i++){
    for(n=0, j=mem.aiFreelist[i]; j>=0; j = mem.aPool[j].u.list.next, n++){}
    fprintf(out, "freelist items of size %d: %d\n", POW2_MIN << i, n);
  }
  fprintf(out, "mem.nAlloc       = %llu\n", mem.nAlloc);
  fprintf(out, "mem.totalAlloc   = %llu\n", mem.totalAlloc);
  fprintf(out, "mem.totalExcess  = %llu\n", mem.totalExcess);
  fprintf(out, "mem.currentOut   = %u\n", mem.currentOut);
  fprintf(out, "mem.currentCount = %u\n", mem.currentCount);
  fprintf(out, "mem.maxOut       = %u\n", mem.maxOut);
  fprintf(out, "mem.maxCount     = %u\n", mem.maxCount);
  fprintf(out, "mem.maxRequest   = %u\n", mem.maxRequest);
  sqlite3_mutex_leave(mem.mutex);
  if( out==stdout ){
    fflush(stdout);
  }else{
    fclose(out);
  }
#endif
}


#endif /* !SQLITE_POW2_MEMORY_SIZE */

/************** End of mem5.c ************************************************/
/************** Begin file mutex.c *******************************************/
/*
** 2007 August 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes.
**
** The implementation in this file does not provide any mutual
** exclusion and is thus suitable for use only in applications
** that use SQLite in a single thread.  But this implementation
** does do a lot of error checking on mutexes to make sure they
** are called correctly and at appropriate times.  Hence, this
** implementation is suitable for testing.
** debugging purposes
**
** $Id: mutex.c,v 1.17 2008/03/26 18:34:43 danielk1977 Exp $
*/

#ifdef SQLITE_MUTEX_NOOP_DEBUG
/*
** In this implementation, mutexes do not provide any mutual exclusion.
** But the error checking is provided.  This implementation is useful
** for test purposes.
*/

/*
** The mutex object
*/
struct sqlite3_mutex {
  int id;     /* The mutex type */
  int cnt;    /* Number of entries without a matching leave */
};

/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated. 
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int id){
  static sqlite3_mutex aStatic[6];
  sqlite3_mutex *pNew = 0;
  switch( id ){
    case SQLITE_MUTEX_FAST:
    case SQLITE_MUTEX_RECURSIVE: {
      pNew = sqlite3_malloc(sizeof(*pNew));
      if( pNew ){
        pNew->id = id;
        pNew->cnt = 0;
      }
      break;
    }
    default: {
      assert( id-2 >= 0 );
      assert( id-2 < sizeof(aStatic)/sizeof(aStatic[0]) );
      pNew = &aStatic[id-2];
      pNew->id = id;
      break;
    }
  }
  return pNew;
}

/*
** This routine deallocates a previously allocated mutex.
*/
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
  assert( p );
  assert( p->cnt==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  sqlite3_free(p);
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  p->cnt++;
}
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  p->cnt++;
  return SQLITE_OK;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
  assert( p );
  assert( sqlite3_mutex_held(p) );
  p->cnt--;
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
}

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
  return p==0 || p->cnt>0;
}
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
  return p==0 || p->cnt==0;
}
#endif /* SQLITE_MUTEX_NOOP_DEBUG */

/************** End of mutex.c ***********************************************/
/************** Begin file mutex_os2.c ***************************************/
/*
** 2007 August 28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes for OS/2
**
** $Id: mutex_os2.c,v 1.6 2008/03/26 18:34:43 danielk1977 Exp $
*/

/*
** The code in this file is only used if SQLITE_MUTEX_OS2 is defined.
** See the mutex.h file for details.
*/
#ifdef SQLITE_MUTEX_OS2

/********************** OS/2 Mutex Implementation **********************
**
** This implementation of mutexes is built using the OS/2 API.
*/

/*
** The mutex object
** Each recursive mutex is an instance of the following structure.
*/
struct sqlite3_mutex {
  HMTX mutex;       /* Mutex controlling the lock */
  int  id;          /* Mutex type */
  int  nRef;        /* Number of references */
  TID  owner;       /* Thread holding this mutex */
};

#define OS2_MUTEX_INITIALIZER   0,0,0,0

/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated. 
** SQLite will unwind its stack and return an error.  The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST               0
** <li>  SQLITE_MUTEX_RECURSIVE          1
** <li>  SQLITE_MUTEX_STATIC_MASTER      2
** <li>  SQLITE_MUTEX_STATIC_MEM         3
** <li>  SQLITE_MUTEX_STATIC_PRNG        4
** </ul>
**
** The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  But SQLite will only request a recursive mutex in
** cases where it really needs one.  If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex.  Three static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  But for the static
** mutex types, the same mutex is returned on every call that has
** the same type number.
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int iType){
  sqlite3_mutex *p = NULL;
  switch( iType ){
    case SQLITE_MUTEX_FAST:
    case SQLITE_MUTEX_RECURSIVE: {
      p = sqlite3MallocZero( sizeof(*p) );
      if( p ){
        p->id = iType;
        if( DosCreateMutexSem( 0, &p->mutex, 0, FALSE ) != NO_ERROR ){
          sqlite3_free( p );
          p = NULL;
        }
      }
      break;
    }
    default: {
      static volatile int isInit = 0;
      static sqlite3_mutex staticMutexes[] = {
        { OS2_MUTEX_INITIALIZER, },
        { OS2_MUTEX_INITIALIZER, },
        { OS2_MUTEX_INITIALIZER, },
        { OS2_MUTEX_INITIALIZER, },
        { OS2_MUTEX_INITIALIZER, },
        { OS2_MUTEX_INITIALIZER, },
      };
      if ( !isInit ){
        APIRET rc;
        PTIB ptib;
        PPIB ppib;
        HMTX mutex;
        char name[32];
        DosGetInfoBlocks( &ptib, &ppib );
        sqlite3_snprintf( sizeof(name), name, "\\SEM32\\SQLITE%04x",
                          ppib->pib_ulpid );
        while( !isInit ){
          mutex = 0;
          rc = DosCreateMutexSem( name, &mutex, 0, FALSE);
          if( rc == NO_ERROR ){
            int i;
            if( !isInit ){
              for( i = 0; i < sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++ ){
                DosCreateMutexSem( 0, &staticMutexes[i].mutex, 0, FALSE );
              }
              isInit = 1;
            }
            DosCloseMutexSem( mutex );
          }else if( rc == ERROR_DUPLICATE_NAME ){
            DosSleep( 1 );
          }else{
            return p;
          }
        }
      }
      assert( iType-2 >= 0 );
      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
      p = &staticMutexes[iType-2];
      p->id = iType;
      break;
    }
  }
  return p;
}


/*
** This routine deallocates a previously allocated mutex.
** SQLite is careful to deallocate every mutex that it allocates.
*/
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
  assert( p );
  assert( p->nRef==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  DosCloseMutexSem( p->mutex );
  sqlite3_free( p );
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
  TID tid;
  PID holder1;
  ULONG holder2;
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
  DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
  p->owner = tid;
  p->nRef++;
}
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
  int rc;
  TID tid;
  PID holder1;
  ULONG holder2;
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR) {
    DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
    p->owner = tid;
    p->nRef++;
    rc = SQLITE_OK;
  } else {
    rc = SQLITE_BUSY;
  }

  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
  TID tid;
  PID holder1;
  ULONG holder2;
  assert( p->nRef>0 );
  DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
  assert( p->owner==tid );
  p->nRef--;
  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
  DosReleaseMutexSem(p->mutex);
}

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
  TID tid;
  PID pid;
  ULONG ulCount;
  PTIB ptib;
  if( p!=0 ) {
    DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  } else {
    DosGetInfoBlocks(&ptib, NULL);
    tid = ptib->tib_ptib2->tib2_ultid;
  }
  return p==0 || (p->nRef!=0 && p->owner==tid);
}
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
  TID tid;
  PID pid;
  ULONG ulCount;
  PTIB ptib;
  if( p!= 0 ) {
    DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  } else {
    DosGetInfoBlocks(&ptib, NULL);
    tid = ptib->tib_ptib2->tib2_ultid;
  }
  return p==0 || p->nRef==0 || p->owner!=tid;
}
#endif /* SQLITE_MUTEX_OS2 */

/************** End of mutex_os2.c *******************************************/
/************** Begin file mutex_unix.c **************************************/
/*
** 2007 August 28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes for pthreads
**
** $Id: mutex_unix.c,v 1.7 2008/03/29 12:47:27 rse Exp $
*/

/*
** The code in this file is only used if we are compiling threadsafe
** under unix with pthreads.
**
** Note that this implementation requires a version of pthreads that
** supports recursive mutexes.
*/
#ifdef SQLITE_MUTEX_PTHREADS

#include <pthread.h>


/*
** Each recursive mutex is an instance of the following structure.
*/
struct sqlite3_mutex {
  pthread_mutex_t mutex;     /* Mutex controlling the lock */
  int id;                    /* Mutex type */
  int nRef;                  /* Number of entrances */
  pthread_t owner;           /* Thread that is within this mutex */
#ifdef SQLITE_DEBUG
  int trace;                 /* True to trace changes */
#endif
};
#ifdef SQLITE_DEBUG
#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0, 0 }
#else
#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0 }
#endif

/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated.  SQLite
** will unwind its stack and return an error.  The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** </ul>
**
** The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  But SQLite will only request a recursive mutex in
** cases where it really needs one.  If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex.  Three static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  But for the static 
** mutex types, the same mutex is returned on every call that has
** the same type number.
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int iType){
  static sqlite3_mutex staticMutexes[] = {
    SQLITE3_MUTEX_INITIALIZER,
    SQLITE3_MUTEX_INITIALIZER,
    SQLITE3_MUTEX_INITIALIZER,
    SQLITE3_MUTEX_INITIALIZER,
    SQLITE3_MUTEX_INITIALIZER,
    SQLITE3_MUTEX_INITIALIZER
  };
  sqlite3_mutex *p;
  switch( iType ){
    case SQLITE_MUTEX_RECURSIVE: {
      p = sqlite3MallocZero( sizeof(*p) );
      if( p ){
#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
        /* If recursive mutexes are not available, we will have to
        ** build our own.  See below. */
        pthread_mutex_init(&p->mutex, 0);
#else
        /* Use a recursive mutex if it is available */
        pthread_mutexattr_t recursiveAttr;
        pthread_mutexattr_init(&recursiveAttr);
        pthread_mutexattr_settype(&recursiveAttr, PTHREAD_MUTEX_RECURSIVE);
        pthread_mutex_init(&p->mutex, &recursiveAttr);
        pthread_mutexattr_destroy(&recursiveAttr);
#endif
        p->id = iType;
      }
      break;
    }
    case SQLITE_MUTEX_FAST: {
      p = sqlite3MallocZero( sizeof(*p) );
      if( p ){
        p->id = iType;
        pthread_mutex_init(&p->mutex, 0);
      }
      break;
    }
    default: {
      assert( iType-2 >= 0 );
      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
      p = &staticMutexes[iType-2];
      p->id = iType;
      break;
    }
  }
  return p;
}


/*
** This routine deallocates a previously
** allocated mutex.  SQLite is careful to deallocate every
** mutex that it allocates.
*/
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
  assert( p );
  assert( p->nRef==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  pthread_mutex_destroy(&p->mutex);
  sqlite3_free(p);
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );

#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
  /* If recursive mutexes are not available, then we have to grow
  ** our own.  This implementation assumes that pthread_equal()
  ** is atomic - that it cannot be deceived into thinking self
  ** and p->owner are equal if p->owner changes between two values
  ** that are not equal to self while the comparison is taking place.
  ** This implementation also assumes a coherent cache - that 
  ** separate processes cannot read different values from the same
  ** address at the same time.  If either of these two conditions
  ** are not met, then the mutexes will fail and problems will result.
  */
  {
    pthread_t self = pthread_self();
    if( p->nRef>0 && pthread_equal(p->owner, self) ){
      p->nRef++;
    }else{
      pthread_mutex_lock(&p->mutex);
      assert( p->nRef==0 );
      p->owner = self;
      p->nRef = 1;
    }
  }
#else
  /* Use the built-in recursive mutexes if they are available.
  */
  pthread_mutex_lock(&p->mutex);
  p->owner = pthread_self();
  p->nRef++;
#endif

#ifdef SQLITE_DEBUG
  if( p->trace ){
    printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
  }
#endif
}
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
  int rc;
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );

#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
  /* If recursive mutexes are not available, then we have to grow
  ** our own.  This implementation assumes that pthread_equal()
  ** is atomic - that it cannot be deceived into thinking self
  ** and p->owner are equal if p->owner changes between two values
  ** that are not equal to self while the comparison is taking place.
  ** This implementation also assumes a coherent cache - that 
  ** separate processes cannot read different values from the same
  ** address at the same time.  If either of these two conditions
  ** are not met, then the mutexes will fail and problems will result.
  */
  {
    pthread_t self = pthread_self();
    if( p->nRef>0 && pthread_equal(p->owner, self) ){
      p->nRef++;
      rc = SQLITE_OK;
    }else if( pthread_mutex_lock(&p->mutex)==0 ){
      assert( p->nRef==0 );
      p->owner = self;
      p->nRef = 1;
      rc = SQLITE_OK;
    }else{
      rc = SQLITE_BUSY;
    }
  }
#else
  /* Use the built-in recursive mutexes if they are available.
  */
  if( pthread_mutex_trylock(&p->mutex)==0 ){
    p->owner = pthread_self();
    p->nRef++;
    rc = SQLITE_OK;
  }else{
    rc = SQLITE_BUSY;
  }
#endif

#ifdef SQLITE_DEBUG
  if( rc==SQLITE_OK && p->trace ){
    printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
  }
#endif
  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
  assert( p );
  assert( sqlite3_mutex_held(p) );
  p->nRef--;
  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );

#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
  if( p->nRef==0 ){
    pthread_mutex_unlock(&p->mutex);
  }
#else
  pthread_mutex_unlock(&p->mutex);
#endif

#ifdef SQLITE_DEBUG
  if( p->trace ){
    printf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
  }
#endif
}

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use only inside assert() statements.  On some platforms,
** there might be race conditions that can cause these routines to
** deliver incorrect results.  In particular, if pthread_equal() is
** not an atomic operation, then these routines might delivery
** incorrect results.  On most platforms, pthread_equal() is a 
** comparison of two integers and is therefore atomic.  But we are
** told that HPUX is not such a platform.  If so, then these routines
** will not always work correctly on HPUX.
**
** On those platforms where pthread_equal() is not atomic, SQLite
** should be compiled without -DSQLITE_DEBUG and with -DNDEBUG to
** make sure no assert() statements are evaluated and hence these
** routines are never called.
*/
#ifndef NDEBUG
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
  return p==0 || (p->nRef!=0 && pthread_equal(p->owner, pthread_self()));
}
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
  return p==0 || p->nRef==0 || pthread_equal(p->owner, pthread_self())==0;
}
#endif
#endif /* SQLITE_MUTEX_PTHREAD */

/************** End of mutex_unix.c ******************************************/
/************** Begin file mutex_w32.c ***************************************/
/*
** 2007 August 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes for win32
**
** $Id: mutex_w32.c,v 1.6 2008/03/26 18:34:43 danielk1977 Exp $
*/

/*
** The code in this file is only used if we are compiling multithreaded
** on a win32 system.
*/
#ifdef SQLITE_MUTEX_W32

/*
** Each recursive mutex is an instance of the following structure.
*/
struct sqlite3_mutex {
  CRITICAL_SECTION mutex;    /* Mutex controlling the lock */
  int id;                    /* Mutex type */
  int nRef;                  /* Number of enterances */
  DWORD owner;               /* Thread holding this mutex */
};

/*
** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
**
** Here is an interesting observation:  Win95, Win98, and WinME lack
** the LockFileEx() API.  But we can still statically link against that
** API as long as we don't call it win running Win95/98/ME.  A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
*/
#if OS_WINCE
# define mutexIsNT()  (1)
#else
  static int mutexIsNT(void){
    static int osType = 0;
    if( osType==0 ){
      OSVERSIONINFO sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      GetVersionEx(&sInfo);
      osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return osType==2;
  }
#endif /* OS_WINCE */


/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated.  SQLite
** will unwind its stack and return an error.  The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST               0
** <li>  SQLITE_MUTEX_RECURSIVE          1
** <li>  SQLITE_MUTEX_STATIC_MASTER      2
** <li>  SQLITE_MUTEX_STATIC_MEM         3
** <li>  SQLITE_MUTEX_STATIC_PRNG        4
** </ul>
**
** The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  But SQLite will only request a recursive mutex in
** cases where it really needs one.  If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex.  Three static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  But for the static 
** mutex types, the same mutex is returned on every call that has
** the same type number.
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int iType){
  sqlite3_mutex *p;

  switch( iType ){
    case SQLITE_MUTEX_FAST:
    case SQLITE_MUTEX_RECURSIVE: {
      p = sqlite3MallocZero( sizeof(*p) );
      if( p ){
        p->id = iType;
        InitializeCriticalSection(&p->mutex);
      }
      break;
    }
    default: {
      static sqlite3_mutex staticMutexes[6];
      static int isInit = 0;
      while( !isInit ){
        static long lock = 0;
        if( InterlockedIncrement(&lock)==1 ){
          int i;
          for(i=0; i<sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++){
            InitializeCriticalSection(&staticMutexes[i].mutex);
          }
          isInit = 1;
        }else{
          Sleep(1);
        }
      }
      assert( iType-2 >= 0 );
      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
      p = &staticMutexes[iType-2];
      p->id = iType;
      break;
    }
  }
  return p;
}


/*
** This routine deallocates a previously
** allocated mutex.  SQLite is careful to deallocate every
** mutex that it allocates.
*/
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
  assert( p );
  assert( p->nRef==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  DeleteCriticalSection(&p->mutex);
  sqlite3_free(p);
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  EnterCriticalSection(&p->mutex);
  p->owner = GetCurrentThreadId(); 
  p->nRef++;
}
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
  int rc = SQLITE_BUSY;
  assert( p );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
  /*
  ** The sqlite3_mutex_try() routine is very rarely used, and when it
  ** is used it is merely an optimization.  So it is OK for it to always
  ** fail.  
  **
  ** The TryEnterCriticalSection() interface is only available on WinNT.
  ** And some windows compilers complain if you try to use it without
  ** first doing some #defines that prevent SQLite from building on Win98.
  ** For that reason, we will omit this optimization for now.  See
  ** ticket #2685.
  */
#if 0
  if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
    p->owner = GetCurrentThreadId();
    p->nRef++;
    rc = SQLITE_OK;
  }
#endif
  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
  assert( p->nRef>0 );
  assert( p->owner==GetCurrentThreadId() );
  p->nRef--;
  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
  LeaveCriticalSection(&p->mutex);
}

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use only inside assert() statements.
*/
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
  return p==0 || (p->nRef!=0 && p->owner==GetCurrentThreadId());
}
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
  return p==0 || p->nRef==0 || p->owner!=GetCurrentThreadId();
}
#endif /* SQLITE_MUTEX_W32 */

/************** End of mutex_w32.c *******************************************/
/************** Begin file malloc.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Memory allocation functions used throughout sqlite.
**
**
** $Id: malloc.c,v 1.15 2008/03/26 18:34:43 danielk1977 Exp $
*/

/*
** This routine runs when the memory allocator sees that the
** total memory allocation is about to exceed the soft heap
** limit.
*/
static void softHeapLimitEnforcer(
  void *NotUsed, 
  sqlite3_int64 inUse,
  int allocSize
){
  sqlite3_release_memory(allocSize);
}

/*
** Set the soft heap-size limit for the current thread. Passing a
** zero or negative value indicates no limit.
*/
SQLITE_API void sqlite3_soft_heap_limit(int n){
  sqlite3_uint64 iLimit;
  int overage;
  if( n<0 ){
    iLimit = 0;
  }else{
    iLimit = n;
  }
  if( iLimit>0 ){
    sqlite3_memory_alarm(softHeapLimitEnforcer, 0, iLimit);
  }else{
    sqlite3_memory_alarm(0, 0, 0);
  }
  overage = sqlite3_memory_used() - n;
  if( overage>0 ){
    sqlite3_release_memory(overage);
  }
}

/*
** Release memory held by SQLite instances created by the current thread.
*/
SQLITE_API int sqlite3_release_memory(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  int nRet = sqlite3VdbeReleaseMemory(n);
  nRet += sqlite3PagerReleaseMemory(n-nRet);
  return nRet;
#else
  return SQLITE_OK;
#endif
}


/*
** Allocate and zero memory.
*/ 
SQLITE_PRIVATE void *sqlite3MallocZero(unsigned n){
  void *p = sqlite3_malloc(n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, unsigned n){
  void *p = sqlite3DbMallocRaw(db, n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, unsigned n){
  void *p = 0;
  if( !db || db->mallocFailed==0 ){
    p = sqlite3_malloc(n);
    if( !p && db ){
      db->mallocFailed = 1;
    }
  }
  return p;
}

/*
** Resize the block of memory pointed to by p to n bytes. If the
** resize fails, set the mallocFailed flag inthe connection object.
*/
SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, int n){
  void *pNew = 0;
  if( db->mallocFailed==0 ){
    pNew = sqlite3_realloc(p, n);
    if( !pNew ){
      db->mallocFailed = 1;
    }
  }
  return pNew;
}

/*
** Attempt to reallocate p.  If the reallocation fails, then free p
** and set the mallocFailed flag in the database connection.
*/
SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, int n){
  void *pNew;
  pNew = sqlite3DbRealloc(db, p, n);
  if( !pNew ){
    sqlite3_free(p);
  }
  return pNew;
}

/*
** Make a copy of a string in memory obtained from sqliteMalloc(). These 
** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This
** is because when memory debugging is turned on, these two functions are 
** called via macros that record the current file and line number in the
** ThreadData structure.
*/
SQLITE_PRIVATE char *sqlite3StrDup(const char *z){
  char *zNew;
  int n;
  if( z==0 ) return 0;
  n = strlen(z)+1;
  zNew = sqlite3_malloc(n);
  if( zNew ) memcpy(zNew, z, n);
  return zNew;
}
SQLITE_PRIVATE char *sqlite3StrNDup(const char *z, int n){
  char *zNew;
  if( z==0 ) return 0;
  zNew = sqlite3_malloc(n+1);
  if( zNew ){
    memcpy(zNew, z, n);
    zNew[n] = 0;
  }
  return zNew;
}

SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3 *db, const char *z){
  char *zNew = sqlite3StrDup(z);
  if( z && !zNew ){
    db->mallocFailed = 1;
  }
  return zNew;
}
SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, int n){
  char *zNew = sqlite3StrNDup(z, n);
  if( z && !zNew ){
    db->mallocFailed = 1;
  }
  return zNew;
}

/*
** Create a string from the 2nd and subsequent arguments (up to the
** first NULL argument), store the string in memory obtained from
** sqliteMalloc() and make the pointer indicated by the 1st argument
** point to that string.  The 1st argument must either be NULL or 
** point to memory obtained from sqliteMalloc().
*/
SQLITE_PRIVATE void sqlite3SetString(char **pz, ...){
  va_list ap;
  int nByte;
  const char *z;
  char *zResult;

  assert( pz!=0 );
  nByte = 1;
  va_start(ap, pz);
  while( (z = va_arg(ap, const char*))!=0 ){
    nByte += strlen(z);
  }
  va_end(ap);
  sqlite3_free(*pz);
  *pz = zResult = sqlite3_malloc(nByte);
  if( zResult==0 ){
    return;
  }
  *zResult = 0;
  va_start(ap, pz);
  while( (z = va_arg(ap, const char*))!=0 ){
    int n = strlen(z);
    memcpy(zResult, z, n);
    zResult += n;
  }
  zResult[0] = 0;
  va_end(ap);
}


/*
** This function must be called before exiting any API function (i.e. 
** returning control to the user) that has called sqlite3_malloc or
** sqlite3_realloc.
**
** The returned value is normally a copy of the second argument to this
** function. However, if a malloc() failure has occured since the previous
** invocation SQLITE_NOMEM is returned instead. 
**
** If the first argument, db, is not NULL and a malloc() error has occured,
** then the connection error-code (the value returned by sqlite3_errcode())
** is set to SQLITE_NOMEM.
*/
SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){
  /* If the db handle is not NULL, then we must hold the connection handle
  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
  ** is unsafe, as is the call to sqlite3Error().
  */
  assert( !db || sqlite3_mutex_held(db->mutex) );
  if( db && db->mallocFailed ){
    sqlite3Error(db, SQLITE_NOMEM, 0);
    db->mallocFailed = 0;
    rc = SQLITE_NOMEM;
  }
  return rc & (db ? db->errMask : 0xff);
}

/************** End of malloc.c **********************************************/
/************** Begin file printf.c ******************************************/
/*
** The "printf" code that follows dates from the 1980's.  It is in
** the public domain.  The original comments are included here for
** completeness.  They are very out-of-date but might be useful as
** an historical reference.  Most of the "enhancements" have been backed
** out so that the functionality is now the same as standard printf().
**
**************************************************************************
**
** The following modules is an enhanced replacement for the "printf" subroutines
** found in the standard C library.  The following enhancements are
** supported:
**
**      +  Additional functions.  The standard set of "printf" functions
**         includes printf, fprintf, sprintf, vprintf, vfprintf, and
**         vsprintf.  This module adds the following:
**
**           *  snprintf -- Works like sprintf, but has an extra argument
**                          which is the size of the buffer written to.
**
**           *  mprintf --  Similar to sprintf.  Writes output to memory
**                          obtained from malloc.
**
**           *  xprintf --  Calls a function to dispose of output.
**
**           *  nprintf --  No output, but returns the number of characters
**                          that would have been output by printf.
**
**           *  A v- version (ex: vsnprintf) of every function is also
**              supplied.
**
**      +  A few extensions to the formatting notation are supported:
**
**           *  The "=" flag (similar to "-") causes the output to be
**              be centered in the appropriately sized field.
**
**           *  The %b field outputs an integer in binary notation.
**
**           *  The %c field now accepts a precision.  The character output
**              is repeated by the number of times the precision specifies.
**
**           *  The %' field works like %c, but takes as its character the
**              next character of the format string, instead of the next
**              argument.  For example,  printf("%.78'-")  prints 78 minus
**              signs, the same as  printf("%.78c",'-').
**
**      +  When compiled using GCC on a SPARC, this version of printf is
**         faster than the library printf for SUN OS 4.1.
**
**      +  All functions are fully reentrant.
**
*/

/*
** Conversion types fall into various categories as defined by the
** following enumeration.
*/
#define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
#define etFLOAT       2 /* Floating point.  %f */
#define etEXP         3 /* Exponentional notation. %e and %E */
#define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
#define etSIZE        5 /* Return number of characters processed so far. %n */
#define etSTRING      6 /* Strings. %s */
#define etDYNSTRING   7 /* Dynamically allocated strings. %z */
#define etPERCENT     8 /* Percent symbol. %% */
#define etCHARX       9 /* Characters. %c */
/* The rest are extensions, not normally found in printf() */
#define etCHARLIT    10 /* Literal characters.  %' */
#define etSQLESCAPE  11 /* Strings with '\'' doubled.  %q */
#define etSQLESCAPE2 12 /* Strings with '\'' doubled and enclosed in '',
                          NULL pointers replaced by SQL NULL.  %Q */
#define etTOKEN      13 /* a pointer to a Token structure */
#define etSRCLIST    14 /* a pointer to a SrcList */
#define etPOINTER    15 /* The %p conversion */
#define etSQLESCAPE3 16 /* %w -> Strings with '\"' doubled */
#define etORDINAL    17 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */


/*
** An "etByte" is an 8-bit unsigned value.
*/
typedef unsigned char etByte;

/*
** Each builtin conversion character (ex: the 'd' in "%d") is described
** by an instance of the following structure
*/
typedef struct et_info {   /* Information about each format field */
  char fmttype;            /* The format field code letter */
  etByte base;             /* The base for radix conversion */
  etByte flags;            /* One or more of FLAG_ constants below */
  etByte type;             /* Conversion paradigm */
  etByte charset;          /* Offset into aDigits[] of the digits string */
  etByte prefix;           /* Offset into aPrefix[] of the prefix string */
} et_info;

/*
** Allowed values for et_info.flags
*/
#define FLAG_SIGNED  1     /* True if the value to convert is signed */
#define FLAG_INTERN  2     /* True if for internal use only */
#define FLAG_STRING  4     /* Allow infinity precision */


/*
** The following table is searched linearly, so it is good to put the
** most frequently used conversion types first.
*/
static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
static const char aPrefix[] = "-x0\000X0";
static const et_info fmtinfo[] = {
  {  'd', 10, 1, etRADIX,      0,  0 },
  {  's',  0, 4, etSTRING,     0,  0 },
  {  'g',  0, 1, etGENERIC,    30, 0 },
  {  'z',  0, 4, etDYNSTRING,  0,  0 },
  {  'q',  0, 4, etSQLESCAPE,  0,  0 },
  {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
  {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
  {  'c',  0, 0, etCHARX,      0,  0 },
  {  'o',  8, 0, etRADIX,      0,  2 },
  {  'u', 10, 0, etRADIX,      0,  0 },
  {  'x', 16, 0, etRADIX,      16, 1 },
  {  'X', 16, 0, etRADIX,      0,  4 },
#ifndef SQLITE_OMIT_FLOATING_POINT
  {  'f',  0, 1, etFLOAT,      0,  0 },
  {  'e',  0, 1, etEXP,        30, 0 },
  {  'E',  0, 1, etEXP,        14, 0 },
  {  'G',  0, 1, etGENERIC,    14, 0 },
#endif
  {  'i', 10, 1, etRADIX,      0,  0 },
  {  'n',  0, 0, etSIZE,       0,  0 },
  {  '%',  0, 0, etPERCENT,    0,  0 },
  {  'p', 16, 0, etPOINTER,    0,  1 },
  {  'T',  0, 2, etTOKEN,      0,  0 },
  {  'S',  0, 2, etSRCLIST,    0,  0 },
  {  'r', 10, 3, etORDINAL,    0,  0 },
};
#define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))

/*
** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
** conversions will work.
*/
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** "*val" is a double such that 0.1 <= *val < 10.0
** Return the ascii code for the leading digit of *val, then
** multiply "*val" by 10.0 to renormalize.
**
** Example:
**     input:     *val = 3.14159
**     output:    *val = 1.4159    function return = '3'
**
** The counter *cnt is incremented each time.  After counter exceeds
** 16 (the number of significant digits in a 64-bit float) '0' is
** always returned.
*/
static int et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
  int digit;
  LONGDOUBLE_TYPE d;
  if( (*cnt)++ >= 16 ) return '0';
  digit = (int)*val;
  d = digit;
  digit += '0';
  *val = (*val - d)*10.0;
  return digit;
}
#endif /* SQLITE_OMIT_FLOATING_POINT */

/*
** Append N space characters to the given string buffer.
*/
static void appendSpace(StrAccum *pAccum, int N){
  static const char zSpaces[] = "                             ";
  while( N>=sizeof(zSpaces)-1 ){
    sqlite3StrAccumAppend(pAccum, zSpaces, sizeof(zSpaces)-1);
    N -= sizeof(zSpaces)-1;
  }
  if( N>0 ){
    sqlite3StrAccumAppend(pAccum, zSpaces, N);
  }
}

/*
** On machines with a small stack size, you can redefine the
** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
** smaller values some %f conversions may go into an infinite loop.
*/
#ifndef SQLITE_PRINT_BUF_SIZE
# define SQLITE_PRINT_BUF_SIZE 350
#endif
#define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */

/*
** The root program.  All variations call this core.
**
** INPUTS:
**   func   This is a pointer to a function taking three arguments
**            1. A pointer to anything.  Same as the "arg" parameter.
**            2. A pointer to the list of characters to be output
**               (Note, this list is NOT null terminated.)
**            3. An integer number of characters to be output.
**               (Note: This number might be zero.)
**
**   arg    This is the pointer to anything which will be passed as the
**          first argument to "func".  Use it for whatever you like.
**
**   fmt    This is the format string, as in the usual print.
**
**   ap     This is a pointer to a list of arguments.  Same as in
**          vfprint.
**
** OUTPUTS:
**          The return value is the total number of characters sent to
**          the function "func".  Returns -1 on a error.
**
** Note that the order in which automatic variables are declared below
** seems to make a big difference in determining how fast this beast
** will run.
*/
static void vxprintf(
  StrAccum *pAccum,                  /* Accumulate results here */
  int useExtended,                   /* Allow extended %-conversions */
  const char *fmt,                   /* Format string */
  va_list ap                         /* arguments */
){
  int c;                     /* Next character in the format string */
  char *bufpt;               /* Pointer to the conversion buffer */
  int precision;             /* Precision of the current field */
  int length;                /* Length of the field */
  int idx;                   /* A general purpose loop counter */
  int width;                 /* Width of the current field */
  etByte flag_leftjustify;   /* True if "-" flag is present */
  etByte flag_plussign;      /* True if "+" flag is present */
  etByte flag_blanksign;     /* True if " " flag is present */
  etByte flag_alternateform; /* True if "#" flag is present */
  etByte flag_altform2;      /* True if "!" flag is present */
  etByte flag_zeropad;       /* True if field width constant starts with zero */
  etByte flag_long;          /* True if "l" flag is present */
  etByte flag_longlong;      /* True if the "ll" flag is present */
  etByte done;               /* Loop termination flag */
  sqlite_uint64 longvalue;   /* Value for integer types */
  LONGDOUBLE_TYPE realvalue; /* Value for real types */
  const et_info *infop;      /* Pointer to the appropriate info structure */
  char buf[etBUFSIZE];       /* Conversion buffer */
  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
  etByte errorflag = 0;      /* True if an error is encountered */
  etByte xtype;              /* Conversion paradigm */
  char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
#ifndef SQLITE_OMIT_FLOATING_POINT
  int  exp, e2;              /* exponent of real numbers */
  double rounder;            /* Used for rounding floating point values */
  etByte flag_dp;            /* True if decimal point should be shown */
  etByte flag_rtz;           /* True if trailing zeros should be removed */
  etByte flag_exp;           /* True to force display of the exponent */
  int nsd;                   /* Number of significant digits returned */
#endif

  length = 0;
  bufpt = 0;
  for(; (c=(*fmt))!=0; ++fmt){
    if( c!='%' ){
      int amt;
      bufpt = (char *)fmt;
      amt = 1;
      while( (c=(*++fmt))!='%' && c!=0 ) amt++;
      sqlite3StrAccumAppend(pAccum, bufpt, amt);
      if( c==0 ) break;
    }
    if( (c=(*++fmt))==0 ){
      errorflag = 1;
      sqlite3StrAccumAppend(pAccum, "%", 1);
      break;
    }
    /* Find out what flags are present */
    flag_leftjustify = flag_plussign = flag_blanksign = 
     flag_alternateform = flag_altform2 = flag_zeropad = 0;
    done = 0;
    do{
      switch( c ){
        case '-':   flag_leftjustify = 1;     break;
        case '+':   flag_plussign = 1;        break;
        case ' ':   flag_blanksign = 1;       break;
        case '#':   flag_alternateform = 1;   break;
        case '!':   flag_altform2 = 1;        break;
        case '0':   flag_zeropad = 1;         break;
        default:    done = 1;                 break;
      }
    }while( !done && (c=(*++fmt))!=0 );
    /* Get the field width */
    width = 0;
    if( c=='*' ){
      width = va_arg(ap,int);
      if( width<0 ){
        flag_leftjustify = 1;
        width = -width;
      }
      c = *++fmt;
    }else{
      while( c>='0' && c<='9' ){
        width = width*10 + c - '0';
        c = *++fmt;
      }
    }
    if( width > etBUFSIZE-10 ){
      width = etBUFSIZE-10;
    }
    /* Get the precision */
    if( c=='.' ){
      precision = 0;
      c = *++fmt;
      if( c=='*' ){
        precision = va_arg(ap,int);
        if( precision<0 ) precision = -precision;
        c = *++fmt;
      }else{
        while( c>='0' && c<='9' ){
          precision = precision*10 + c - '0';
          c = *++fmt;
        }
      }
    }else{
      precision = -1;
    }
    /* Get the conversion type modifier */
    if( c=='l' ){
      flag_long = 1;
      c = *++fmt;
      if( c=='l' ){
        flag_longlong = 1;
        c = *++fmt;
      }else{
        flag_longlong = 0;
      }
    }else{
      flag_long = flag_longlong = 0;
    }
    /* Fetch the info entry for the field */
    infop = 0;
    for(idx=0; idx<etNINFO; idx++){
      if( c==fmtinfo[idx].fmttype ){
        infop = &fmtinfo[idx];
        if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
          xtype = infop->type;
        }else{
          return;
        }
        break;
      }
    }
    zExtra = 0;
    if( infop==0 ){
      return;
    }


    /* Limit the precision to prevent overflowing buf[] during conversion */
    if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
      precision = etBUFSIZE-40;
    }

    /*
    ** At this point, variables are initialized as follows:
    **
    **   flag_alternateform          TRUE if a '#' is present.
    **   flag_altform2               TRUE if a '!' is present.
    **   flag_plussign               TRUE if a '+' is present.
    **   flag_leftjustify            TRUE if a '-' is present or if the
    **                               field width was negative.
    **   flag_zeropad                TRUE if the width began with 0.
    **   flag_long                   TRUE if the letter 'l' (ell) prefixed
    **                               the conversion character.
    **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
    **                               the conversion character.
    **   flag_blanksign              TRUE if a ' ' is present.
    **   width                       The specified field width.  This is
    **                               always non-negative.  Zero is the default.
    **   precision                   The specified precision.  The default
    **                               is -1.
    **   xtype                       The class of the conversion.
    **   infop                       Pointer to the appropriate info struct.
    */
    switch( xtype ){
      case etPOINTER:
        flag_longlong = sizeof(char*)==sizeof(i64);
        flag_long = sizeof(char*)==sizeof(long int);
        /* Fall through into the next case */
      case etORDINAL:
      case etRADIX:
        if( infop->flags & FLAG_SIGNED ){
          i64 v;
          if( flag_longlong )   v = va_arg(ap,i64);
          else if( flag_long )  v = va_arg(ap,long int);
          else                  v = va_arg(ap,int);
          if( v<0 ){
            longvalue = -v;
            prefix = '-';
          }else{
            longvalue = v;
            if( flag_plussign )        prefix = '+';
            else if( flag_blanksign )  prefix = ' ';
            else                       prefix = 0;
          }
        }else{
          if( flag_longlong )   longvalue = va_arg(ap,u64);
          else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
          else                  longvalue = va_arg(ap,unsigned int);
          prefix = 0;
        }
        if( longvalue==0 ) flag_alternateform = 0;
        if( flag_zeropad && precision<width-(prefix!=0) ){
          precision = width-(prefix!=0);
        }
        bufpt = &buf[etBUFSIZE-1];
        if( xtype==etORDINAL ){
          static const char zOrd[] = "thstndrd";
          int x = longvalue % 10;
          if( x>=4 || (longvalue/10)%10==1 ){
            x = 0;
          }
          buf[etBUFSIZE-3] = zOrd[x*2];
          buf[etBUFSIZE-2] = zOrd[x*2+1];
          bufpt -= 2;
        }
        {
          register const char *cset;      /* Use registers for speed */
          register int base;
          cset = &aDigits[infop->charset];
          base = infop->base;
          do{                                           /*