2** This file is an amalgamation of many separate C source files from SQLite
3** version 3.9.2.  By combining all the individual C code files into this
4** single large file, the entire code can be compiled as a single translation
5** unit.  This allows many compilers to do optimizations that would not be
6** possible if the files were compiled separately.  Performance improvements
7** of 5% or more are commonly seen when SQLite is compiled as a single
8** translation unit.
10** This file is all you need to compile SQLite.  To use SQLite in other
11** programs, you need this file and the "sqlite3.h" header file that defines
12** the programming interface to the SQLite library.  (If you do not have
13** the "sqlite3.h" header file at hand, you will find a copy embedded within
14** the text of this file.  Search for "Begin file sqlite3.h" to find the start
15** of the embedded sqlite3.h header file.) Additional code files may be needed
16** if you want a wrapper to interface SQLite with your choice of programming
17** language. The code for the "sqlite3" command-line shell is also in a
18** separate file. This file contains only code for the core SQLite library.
20#define SQLITE_CORE 1
23# define SQLITE_PRIVATE static
25/************** Begin file sqliteInt.h ***************************************/
27** 2001 September 15
29** The author disclaims copyright to this source code.  In place of
30** a legal notice, here is a blessing:
32**    May you do good and not evil.
33**    May you find forgiveness for yourself and forgive others.
34**    May you share freely, never taking more than you give.
37** Internal interface definitions for SQLite.
40#ifndef _SQLITEINT_H_
41#define _SQLITEINT_H_
44** Include the header file used to customize the compiler options for MSVC.
45** This should be done first so that it can successfully prevent spurious
46** compiler warnings due to subsequent content in this file and other files
47** that are included by this file.
49/************** Include msvc.h in the middle of sqliteInt.h ******************/
50/************** Begin file msvc.h ********************************************/
52** 2015 January 12
54** The author disclaims copyright to this source code.  In place of
55** a legal notice, here is a blessing:
57**    May you do good and not evil.
58**    May you find forgiveness for yourself and forgive others.
59**    May you share freely, never taking more than you give.
63** This file contains code that is specific to MSVC.
65#ifndef _MSVC_H_
66#define _MSVC_H_
68#if defined(_MSC_VER)
69#pragma warning(disable : 4054)
70#pragma warning(disable : 4055)
71#pragma warning(disable : 4100)
72#pragma warning(disable : 4127)
73#pragma warning(disable : 4130)
74#pragma warning(disable : 4152)
75#pragma warning(disable : 4189)
76#pragma warning(disable : 4206)
77#pragma warning(disable : 4210)
78#pragma warning(disable : 4232)
79#pragma warning(disable : 4244)
80#pragma warning(disable : 4305)
81#pragma warning(disable : 4306)
82#pragma warning(disable : 4702)
83#pragma warning(disable : 4706)
84#endif /* defined(_MSC_VER) */
86#endif /* _MSVC_H_ */
88/************** End of msvc.h ************************************************/
89/************** Continuing where we left off in sqliteInt.h ******************/
92** Special setup for VxWorks
94/************** Include vxworks.h in the middle of sqliteInt.h ***************/
95/************** Begin file vxworks.h *****************************************/
97** 2015-03-02
99** The author disclaims copyright to this source code.  In place of
100** a legal notice, here is a blessing:
102**    May you do good and not evil.
103**    May you find forgiveness for yourself and forgive others.
104**    May you share freely, never taking more than you give.
108** This file contains code that is specific to Wind River's VxWorks
110#if defined(__RTP__) || defined(_WRS_KERNEL)
111/* This is VxWorks.  Set up things specially for that OS
113#include <vxWorks.h>
114#include <pthread.h>  /* amalgamator: dontcache */
115#define OS_VXWORKS 1
116#define SQLITE_OS_OTHER 0
120#define HAVE_UTIME 1
122/* This is not VxWorks. */
123#define OS_VXWORKS 0
124#endif /* defined(_WRS_KERNEL) */
126/************** End of vxworks.h *********************************************/
127/************** Continuing where we left off in sqliteInt.h ******************/
130** These #defines should enable >2GB file support on POSIX if the
131** underlying operating system supports it.  If the OS lacks
132** large file support, or if the OS is windows, these should be no-ops.
134** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
135** system #includes.  Hence, this block of code must be the very first
136** code in all source files.
138** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
139** on the compiler command line.  This is necessary if you are compiling
140** on a recent machine (ex: Red Hat 7.2) but you want your code to work
141** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
142** without this option, LFS is enable.  But LFS does not exist in the kernel
143** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
144** portability you should omit LFS.
146** The previous paragraph was written in 2005.  (This paragraph is written
147** on 2008-11-28.) These days, all Linux kernels support large files, so
148** you should probably leave LFS enabled.  But some embedded platforms might
149** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.
151** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
154# define _LARGE_FILE       1
155# ifndef _FILE_OFFSET_BITS
156#   define _FILE_OFFSET_BITS 64
157# endif
158# define _LARGEFILE_SOURCE 1
161/* What version of GCC is being used.  0 means GCC is not being used */
162#ifdef __GNUC__
163# define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)
165# define GCC_VERSION 0
168/* Needed for various definitions... */
169#if defined(__GNUC__) && !defined(_GNU_SOURCE)
170# define _GNU_SOURCE
173#if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
174# define _BSD_SOURCE
178** For MinGW, check to see if we can include the header file containing its
179** version information, among other things.  Normally, this internal MinGW
180** header file would [only] be included automatically by other MinGW header
181** files; however, the contained version information is now required by this
182** header file to work around binary compatibility issues (see below) and
183** this is the only known way to reliably obtain it.  This entire #if block
184** would be completely unnecessary if there was any other way of detecting
185** MinGW via their preprocessor (e.g. if they customized their GCC to define
186** some MinGW-specific macros).  When compiling for MinGW, either the
187** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be
188** defined; otherwise, detection of conditions specific to MinGW will be
189** disabled.
191#if defined(_HAVE_MINGW_H)
192# include "mingw.h"
193#elif defined(_HAVE__MINGW_H)
194# include "_mingw.h"
198** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T
199** define is required to maintain binary compatibility with the MSVC runtime
200** library in use (e.g. for Windows XP).
202#if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \
203    defined(_WIN32) && !defined(_WIN64) && \
204    defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \
205    defined(__MSVCRT__)
206# define _USE_32BIT_TIME_T
209/* The public SQLite interface.  The _FILE_OFFSET_BITS macro must appear
210** first in QNX.  Also, the _USE_32BIT_TIME_T macro must appear first for
211** MinGW.
213/************** Include sqlite3.h in the middle of sqliteInt.h ***************/
214/************** Begin file sqlite3.h *****************************************/
216** 2001 September 15
218** The author disclaims copyright to this source code.  In place of
219** a legal notice, here is a blessing:
221**    May you do good and not evil.
222**    May you find forgiveness for yourself and forgive others.
223**    May you share freely, never taking more than you give.
226** This header file defines the interface that the SQLite library
227** presents to client programs.  If a C-function, structure, datatype,
228** or constant definition does not appear in this file, then it is
229** not a published API of SQLite, is subject to change without
230** notice, and should not be referenced by programs that use SQLite.
232** Some of the definitions that are in this file are marked as
233** "experimental".  Experimental interfaces are normally new
234** features recently added to SQLite.  We do not anticipate changes
235** to experimental interfaces but reserve the right to make minor changes
236** if experience from use "in the wild" suggest such changes are prudent.
238** The official C-language API documentation for SQLite is derived
239** from comments in this file.  This file is the authoritative source
240** on how SQLite interfaces are supposed to operate.
242** The name of this file under configuration management is "sqlite.h.in".
243** The makefile makes some minor changes to this file (such as inserting
244** the version number) and changes its name to "sqlite3.h" as
245** part of the build process.
247#ifndef _SQLITE3_H_
248#define _SQLITE3_H_
249#include <stdarg.h>     /* Needed for the definition of va_list */
252** Make sure we can call this stuff from C++.
254#if 0
255extern "C" {
260** Provide the ability to override linkage features of the interface.
262#ifndef SQLITE_EXTERN
263# define SQLITE_EXTERN extern
265#ifndef SQLITE_API
266# define SQLITE_API
268#ifndef SQLITE_CDECL
269# define SQLITE_CDECL
272# define SQLITE_STDCALL
276** These no-op macros are used in front of interfaces to mark those
277** interfaces as either deprecated or experimental.  New applications
278** should not use deprecated interfaces - they are supported for backwards
279** compatibility only.  Application writers should be aware that
280** experimental interfaces are subject to change in point releases.
282** These macros used to resolve to various kinds of compiler magic that
283** would generate warning messages when they were used.  But that
284** compiler magic ended up generating such a flurry of bug reports
285** that we have taken it all out and gone back to using simple
286** noop macros.
292** Ensure these symbols were not defined by some previous header file.
302** CAPI3REF: Compile-Time Library Version Numbers
304** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
305** evaluates to a string literal that is the SQLite version in the
306** format "X.Y.Z" where X is the major version number (always 3 for
307** SQLite3) and Y is the minor version number and Z is the release number.)^
308** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
309** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
310** numbers used in [SQLITE_VERSION].)^
311** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
312** be larger than the release from which it is derived.  Either Y will
313** be held constant and Z will be incremented or else Y will be incremented
314** and Z will be reset to zero.
316** Since version 3.6.18, SQLite source code has been stored in the
317** <a href="http://www.fossil-scm.org/">Fossil configuration management
318** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
319** a string which identifies a particular check-in of SQLite
320** within its configuration management system.  ^The SQLITE_SOURCE_ID
321** string contains the date and time of the check-in (UTC) and an SHA1
322** hash of the entire source tree.
324** See also: [sqlite3_libversion()],
325** [sqlite3_libversion_number()], [sqlite3_sourceid()],
326** [sqlite_version()] and [sqlite_source_id()].
328#define SQLITE_VERSION        "3.9.2"
329#define SQLITE_VERSION_NUMBER 3009002
330#define SQLITE_SOURCE_ID      "2015-11-02 18:31:45 bda77dda9697c463c3d0704014d51627fceee328"
333** CAPI3REF: Run-Time Library Version Numbers
334** KEYWORDS: sqlite3_version, sqlite3_sourceid
336** These interfaces provide the same information as the [SQLITE_VERSION],
337** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
338** but are associated with the library instead of the header file.  ^(Cautious
339** programmers might include assert() statements in their application to
340** verify that values returned by these interfaces match the macros in
341** the header, and thus ensure that the application is
342** compiled with matching library and header files.
344** <blockquote><pre>
345** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
346** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
347** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
348** </pre></blockquote>)^
350** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
351** macro.  ^The sqlite3_libversion() function returns a pointer to the
352** to the sqlite3_version[] string constant.  The sqlite3_libversion()
353** function is provided for use in DLLs since DLL users usually do not have
354** direct access to string constants within the DLL.  ^The
355** sqlite3_libversion_number() function returns an integer equal to
356** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
357** a pointer to a string constant whose value is the same as the
358** [SQLITE_SOURCE_ID] C preprocessor macro.
360** See also: [sqlite_version()] and [sqlite_source_id()].
362SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
363SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void);
364SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void);
365SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void);
368** CAPI3REF: Run-Time Library Compilation Options Diagnostics
370** ^The sqlite3_compileoption_used() function returns 0 or 1
371** indicating whether the specified option was defined at
372** compile time.  ^The SQLITE_ prefix may be omitted from the
373** option name passed to sqlite3_compileoption_used().
375** ^The sqlite3_compileoption_get() function allows iterating
376** over the list of options that were defined at compile time by
377** returning the N-th compile time option string.  ^If N is out of range,
378** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
379** prefix is omitted from any strings returned by
380** sqlite3_compileoption_get().
382** ^Support for the diagnostic functions sqlite3_compileoption_used()
383** and sqlite3_compileoption_get() may be omitted by specifying the
384** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
386** See also: SQL functions [sqlite_compileoption_used()] and
387** [sqlite_compileoption_get()] and the [compile_options pragma].
390SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName);
391SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N);
395** CAPI3REF: Test To See If The Library Is Threadsafe
397** ^The sqlite3_threadsafe() function returns zero if and only if
398** SQLite was compiled with mutexing code omitted due to the
399** [SQLITE_THREADSAFE] compile-time option being set to 0.
401** SQLite can be compiled with or without mutexes.  When
402** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
403** are enabled and SQLite is threadsafe.  When the
404** [SQLITE_THREADSAFE] macro is 0,
405** the mutexes are omitted.  Without the mutexes, it is not safe
406** to use SQLite concurrently from more than one thread.
408** Enabling mutexes incurs a measurable performance penalty.
409** So if speed is of utmost importance, it makes sense to disable
410** the mutexes.  But for maximum safety, mutexes should be enabled.
411** ^The default behavior is for mutexes to be enabled.
413** This interface can be used by an application to make sure that the
414** version of SQLite that it is linking against was compiled with
415** the desired setting of the [SQLITE_THREADSAFE] macro.
417** This interface only reports on the compile-time mutex setting
418** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
419** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
420** can be fully or partially disabled using a call to [sqlite3_config()]
422** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
423** sqlite3_threadsafe() function shows only the compile-time setting of
424** thread safety, not any run-time changes to that setting made by
425** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
426** is unchanged by calls to sqlite3_config().)^
428** See the [threading mode] documentation for additional information.
430SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void);
433** CAPI3REF: Database Connection Handle
434** KEYWORDS: {database connection} {database connections}
436** Each open SQLite database is represented by a pointer to an instance of
437** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
438** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
439** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
440** and [sqlite3_close_v2()] are its destructors.  There are many other
441** interfaces (such as
442** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
443** [sqlite3_busy_timeout()] to name but three) that are methods on an
444** sqlite3 object.
446typedef struct sqlite3 sqlite3;
449** CAPI3REF: 64-Bit Integer Types
450** KEYWORDS: sqlite_int64 sqlite_uint64
452** Because there is no cross-platform way to specify 64-bit integer types
453** SQLite includes typedefs for 64-bit signed and unsigned integers.
455** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
456** The sqlite_int64 and sqlite_uint64 types are supported for backwards
457** compatibility only.
459** ^The sqlite3_int64 and sqlite_int64 types can store integer values
460** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
461** sqlite3_uint64 and sqlite_uint64 types can store integer values
462** between 0 and +18446744073709551615 inclusive.
464#ifdef SQLITE_INT64_TYPE
465  typedef SQLITE_INT64_TYPE sqlite_int64;
466  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
467#elif defined(_MSC_VER) || defined(__BORLANDC__)
468  typedef __int64 sqlite_int64;
469  typedef unsigned __int64 sqlite_uint64;
471  typedef long long int sqlite_int64;
472  typedef unsigned long long int sqlite_uint64;
474typedef sqlite_int64 sqlite3_int64;
475typedef sqlite_uint64 sqlite3_uint64;
478** If compiling for a processor that lacks floating point support,
479** substitute integer for floating-point.
482# define double sqlite3_int64
486** CAPI3REF: Closing A Database Connection
487** DESTRUCTOR: sqlite3
489** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
490** for the [sqlite3] object.
491** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
492** the [sqlite3] object is successfully destroyed and all associated
493** resources are deallocated.
495** ^If the database connection is associated with unfinalized prepared
496** statements or unfinished sqlite3_backup objects then sqlite3_close()
497** will leave the database connection open and return [SQLITE_BUSY].
498** ^If sqlite3_close_v2() is called with unfinalized prepared statements
499** and/or unfinished sqlite3_backups, then the database connection becomes
500** an unusable "zombie" which will automatically be deallocated when the
501** last prepared statement is finalized or the last sqlite3_backup is
502** finished.  The sqlite3_close_v2() interface is intended for use with
503** host languages that are garbage collected, and where the order in which
504** destructors are called is arbitrary.
506** Applications should [sqlite3_finalize | finalize] all [prepared statements],
507** [sqlite3_blob_close | close] all [BLOB handles], and
508** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
509** with the [sqlite3] object prior to attempting to close the object.  ^If
510** sqlite3_close_v2() is called on a [database connection] that still has
511** outstanding [prepared statements], [BLOB handles], and/or
512** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
513** of resources is deferred until all [prepared statements], [BLOB handles],
514** and [sqlite3_backup] objects are also destroyed.
516** ^If an [sqlite3] object is destroyed while a transaction is open,
517** the transaction is automatically rolled back.
519** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
520** must be either a NULL
521** pointer or an [sqlite3] object pointer obtained
522** from [sqlite3_open()], [sqlite3_open16()], or
523** [sqlite3_open_v2()], and not previously closed.
524** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
525** argument is a harmless no-op.
527SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*);
528SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*);
531** The type for a callback function.
532** This is legacy and deprecated.  It is included for historical
533** compatibility and is not documented.
535typedef int (*sqlite3_callback)(void*,int,char**, char**);
538** CAPI3REF: One-Step Query Execution Interface
539** METHOD: sqlite3
541** The sqlite3_exec() interface is a convenience wrapper around
542** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
543** that allows an application to run multiple statements of SQL
544** without having to use a lot of C code.
546** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
547** semicolon-separate SQL statements passed into its 2nd argument,
548** in the context of the [database connection] passed in as its 1st
549** argument.  ^If the callback function of the 3rd argument to
550** sqlite3_exec() is not NULL, then it is invoked for each result row
551** coming out of the evaluated SQL statements.  ^The 4th argument to
552** sqlite3_exec() is relayed through to the 1st argument of each
553** callback invocation.  ^If the callback pointer to sqlite3_exec()
554** is NULL, then no callback is ever invoked and result rows are
555** ignored.
557** ^If an error occurs while evaluating the SQL statements passed into
558** sqlite3_exec(), then execution of the current statement stops and
559** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
560** is not NULL then any error message is written into memory obtained
561** from [sqlite3_malloc()] and passed back through the 5th parameter.
562** To avoid memory leaks, the application should invoke [sqlite3_free()]
563** on error message strings returned through the 5th parameter of
564** of sqlite3_exec() after the error message string is no longer needed.
565** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
566** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
567** NULL before returning.
569** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
570** routine returns SQLITE_ABORT without invoking the callback again and
571** without running any subsequent SQL statements.
573** ^The 2nd argument to the sqlite3_exec() callback function is the
574** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
575** callback is an array of pointers to strings obtained as if from
576** [sqlite3_column_text()], one for each column.  ^If an element of a
577** result row is NULL then the corresponding string pointer for the
578** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
579** sqlite3_exec() callback is an array of pointers to strings where each
580** entry represents the name of corresponding result column as obtained
581** from [sqlite3_column_name()].
583** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
584** to an empty string, or a pointer that contains only whitespace and/or
585** SQL comments, then no SQL statements are evaluated and the database
586** is not changed.
588** Restrictions:
590** <ul>
591** <li> The application must ensure that the 1st parameter to sqlite3_exec()
592**      is a valid and open [database connection].
593** <li> The application must not close the [database connection] specified by
594**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
595** <li> The application must not modify the SQL statement text passed into
596**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
597** </ul>
599SQLITE_API int SQLITE_STDCALL sqlite3_exec(
600  sqlite3*,                                  /* An open database */
601  const char *sql,                           /* SQL to be evaluated */
602  int (*callback)(void*,int,char**,char**),  /* Callback function */
603  void *,                                    /* 1st argument to callback */
604  char **errmsg                              /* Error msg written here */
608** CAPI3REF: Result Codes
609** KEYWORDS: {result code definitions}
611** Many SQLite functions return an integer result code from the set shown
612** here in order to indicate success or failure.
614** New error codes may be added in future versions of SQLite.
616** See also: [extended result code definitions]
618#define SQLITE_OK           0   /* Successful result */
619/* beginning-of-error-codes */
620#define SQLITE_ERROR        1   /* SQL error or missing database */
621#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
622#define SQLITE_PERM         3   /* Access permission denied */
623#define SQLITE_ABORT        4   /* Callback routine requested an abort */
624#define SQLITE_BUSY         5   /* The database file is locked */
625#define SQLITE_LOCKED       6   /* A table in the database is locked */
626#define SQLITE_NOMEM        7   /* A malloc() failed */
627#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
628#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
629#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
630#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
631#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
632#define SQLITE_FULL        13   /* Insertion failed because database is full */
633#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
634#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
635#define SQLITE_EMPTY       16   /* Database is empty */
636#define SQLITE_SCHEMA      17   /* The database schema changed */
637#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
638#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
639#define SQLITE_MISMATCH    20   /* Data type mismatch */
640#define SQLITE_MISUSE      21   /* Library used incorrectly */
641#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
642#define SQLITE_AUTH        23   /* Authorization denied */
643#define SQLITE_FORMAT      24   /* Auxiliary database format error */
644#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
645#define SQLITE_NOTADB      26   /* File opened that is not a database file */
646#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
647#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
648#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
649#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
650/* end-of-error-codes */
653** CAPI3REF: Extended Result Codes
654** KEYWORDS: {extended result code definitions}
656** In its default configuration, SQLite API routines return one of 30 integer
657** [result codes].  However, experience has shown that many of
658** these result codes are too coarse-grained.  They do not provide as
659** much information about problems as programmers might like.  In an effort to
660** address this, newer versions of SQLite (version 3.3.8 and later) include
661** support for additional result codes that provide more detailed information
662** about errors. These [extended result codes] are enabled or disabled
663** on a per database connection basis using the
664** [sqlite3_extended_result_codes()] API.  Or, the extended code for
665** the most recent error can be obtained using
666** [sqlite3_extended_errcode()].
668#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
669#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
670#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
671#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
672#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
673#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
674#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
675#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
676#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
677#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
678#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
679#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
680#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
682#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
683#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
684#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
685#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
686#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
687#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
688#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
689#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
690#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
691#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
692#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
693#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
694#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
696#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
697#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
699#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
702#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
707#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
721#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
724** CAPI3REF: Flags For File Open Operations
726** These bit values are intended for use in the
727** 3rd parameter to the [sqlite3_open_v2()] interface and
728** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
730#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
731#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
732#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
733#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
734#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
735#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
736#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
737#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
738#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
739#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
740#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
741#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
742#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
743#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
744#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
745#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
746#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
747#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
748#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
749#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
751/* Reserved:                         0x00F00000 */
754** CAPI3REF: Device Characteristics
756** The xDeviceCharacteristics method of the [sqlite3_io_methods]
757** object returns an integer which is a vector of these
758** bit values expressing I/O characteristics of the mass storage
759** device that holds the file that the [sqlite3_io_methods]
760** refers to.
762** The SQLITE_IOCAP_ATOMIC property means that all writes of
763** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
764** mean that writes of blocks that are nnn bytes in size and
765** are aligned to an address which is an integer multiple of
766** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
767** that when data is appended to a file, the data is appended
768** first then the size of the file is extended, never the other
769** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
770** information is written to disk in the same order as calls
771** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
772** after reboot following a crash or power loss, the only bytes in a
773** file that were written at the application level might have changed
774** and that adjacent bytes, even bytes within the same sector are
775** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
776** flag indicate that a file cannot be deleted when open.  The
777** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
778** read-only media and cannot be changed even by processes with
779** elevated privileges.
781#define SQLITE_IOCAP_ATOMIC                 0x00000001
782#define SQLITE_IOCAP_ATOMIC512              0x00000002
783#define SQLITE_IOCAP_ATOMIC1K               0x00000004
784#define SQLITE_IOCAP_ATOMIC2K               0x00000008
785#define SQLITE_IOCAP_ATOMIC4K               0x00000010
786#define SQLITE_IOCAP_ATOMIC8K               0x00000020
787#define SQLITE_IOCAP_ATOMIC16K              0x00000040
788#define SQLITE_IOCAP_ATOMIC32K              0x00000080
789#define SQLITE_IOCAP_ATOMIC64K              0x00000100
790#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
791#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
794#define SQLITE_IOCAP_IMMUTABLE              0x00002000
797** CAPI3REF: File Locking Levels
799** SQLite uses one of these integer values as the second
800** argument to calls it makes to the xLock() and xUnlock() methods
801** of an [sqlite3_io_methods] object.
803#define SQLITE_LOCK_NONE          0
804#define SQLITE_LOCK_SHARED        1
805#define SQLITE_LOCK_RESERVED      2
806#define SQLITE_LOCK_PENDING       3
807#define SQLITE_LOCK_EXCLUSIVE     4
810** CAPI3REF: Synchronization Type Flags
812** When SQLite invokes the xSync() method of an
813** [sqlite3_io_methods] object it uses a combination of
814** these integer values as the second argument.
816** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
817** sync operation only needs to flush data to mass storage.  Inode
818** information need not be flushed. If the lower four bits of the flag
819** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
820** If the lower four bits equal SQLITE_SYNC_FULL, that means
821** to use Mac OS X style fullsync instead of fsync().
823** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
824** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
825** settings.  The [synchronous pragma] determines when calls to the
826** xSync VFS method occur and applies uniformly across all platforms.
827** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
828** energetic or rigorous or forceful the sync operations are and
829** only make a difference on Mac OSX for the default SQLite code.
830** (Third-party VFS implementations might also make the distinction
831** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
832** operating systems natively supported by SQLite, only Mac OSX
833** cares about the difference.)
835#define SQLITE_SYNC_NORMAL        0x00002
836#define SQLITE_SYNC_FULL          0x00003
837#define SQLITE_SYNC_DATAONLY      0x00010
840** CAPI3REF: OS Interface Open File Handle
842** An [sqlite3_file] object represents an open file in the
843** [sqlite3_vfs | OS interface layer].  Individual OS interface
844** implementations will
845** want to subclass this object by appending additional fields
846** for their own use.  The pMethods entry is a pointer to an
847** [sqlite3_io_methods] object that defines methods for performing
848** I/O operations on the open file.
850typedef struct sqlite3_file sqlite3_file;
851struct sqlite3_file {
852  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
856** CAPI3REF: OS Interface File Virtual Methods Object
858** Every file opened by the [sqlite3_vfs.xOpen] method populates an
859** [sqlite3_file] object (or, more commonly, a subclass of the
860** [sqlite3_file] object) with a pointer to an instance of this object.
861** This object defines the methods used to perform various operations
862** against the open file represented by the [sqlite3_file] object.
864** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
865** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
866** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
867** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
868** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
869** to NULL.
871** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
872** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
873** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
874** flag may be ORed in to indicate that only the data of the file
875** and not its inode needs to be synced.
877** The integer values to xLock() and xUnlock() are one of
878** <ul>
879** <li> [SQLITE_LOCK_NONE],
880** <li> [SQLITE_LOCK_SHARED],
882** <li> [SQLITE_LOCK_PENDING], or
884** </ul>
885** xLock() increases the lock. xUnlock() decreases the lock.
886** The xCheckReservedLock() method checks whether any database connection,
887** either in this process or in some other process, is holding a RESERVED,
888** PENDING, or EXCLUSIVE lock on the file.  It returns true
889** if such a lock exists and false otherwise.
891** The xFileControl() method is a generic interface that allows custom
892** VFS implementations to directly control an open file using the
893** [sqlite3_file_control()] interface.  The second "op" argument is an
894** integer opcode.  The third argument is a generic pointer intended to
895** point to a structure that may contain arguments or space in which to
896** write return values.  Potential uses for xFileControl() might be
897** functions to enable blocking locks with timeouts, to change the
898** locking strategy (for example to use dot-file locks), to inquire
899** about the status of a lock, or to break stale locks.  The SQLite
900** core reserves all opcodes less than 100 for its own use.
901** A [file control opcodes | list of opcodes] less than 100 is available.
902** Applications that define a custom xFileControl method should use opcodes
903** greater than 100 to avoid conflicts.  VFS implementations should
904** return [SQLITE_NOTFOUND] for file control opcodes that they do not
905** recognize.
907** The xSectorSize() method returns the sector size of the
908** device that underlies the file.  The sector size is the
909** minimum write that can be performed without disturbing
910** other bytes in the file.  The xDeviceCharacteristics()
911** method returns a bit vector describing behaviors of the
912** underlying device:
914** <ul>
916** <li> [SQLITE_IOCAP_ATOMIC512]
926** </ul>
928** The SQLITE_IOCAP_ATOMIC property means that all writes of
929** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
930** mean that writes of blocks that are nnn bytes in size and
931** are aligned to an address which is an integer multiple of
932** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
933** that when data is appended to a file, the data is appended
934** first then the size of the file is extended, never the other
935** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
936** information is written to disk in the same order as calls
937** to xWrite().
939** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
940** in the unread portions of the buffer with zeros.  A VFS that
941** fails to zero-fill short reads might seem to work.  However,
942** failure to zero-fill short reads will eventually lead to
943** database corruption.
945typedef struct sqlite3_io_methods sqlite3_io_methods;
946struct sqlite3_io_methods {
947  int iVersion;
948  int (*xClose)(sqlite3_file*);
949  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
950  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
951  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
952  int (*xSync)(sqlite3_file*, int flags);
953  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
954  int (*xLock)(sqlite3_file*, int);
955  int (*xUnlock)(sqlite3_file*, int);
956  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
957  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
958  int (*xSectorSize)(sqlite3_file*);
959  int (*xDeviceCharacteristics)(sqlite3_file*);
960  /* Methods above are valid for version 1 */
961  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
962  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
963  void (*xShmBarrier)(sqlite3_file*);
964  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
965  /* Methods above are valid for version 2 */
966  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
967  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
968  /* Methods above are valid for version 3 */
969  /* Additional methods may be added in future releases */
973** CAPI3REF: Standard File Control Opcodes
974** KEYWORDS: {file control opcodes} {file control opcode}
976** These integer constants are opcodes for the xFileControl method
977** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
978** interface.
980** <ul>
982** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
983** opcode causes the xFileControl method to write the current state of
984** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
986** into an integer that the pArg argument points to. This capability
987** is used during testing and is only available when the SQLITE_TEST
988** compile-time option is used.
991** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
992** layer a hint of how large the database file will grow to be during the
993** current transaction.  This hint is not guaranteed to be accurate but it
994** is often close.  The underlying VFS might choose to preallocate database
995** file space based on this hint in order to help writes to the database
996** file run faster.
999** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
1000** extends and truncates the database file in chunks of a size specified
1001** by the user. The fourth argument to [sqlite3_file_control()] should
1002** point to an integer (type int) containing the new chunk-size to use
1003** for the nominated database. Allocating database file space in large
1004** chunks (say 1MB at a time), may reduce file-system fragmentation and
1005** improve performance on some systems.
1008** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
1009** to the [sqlite3_file] object associated with a particular database
1010** connection.  See the [sqlite3_file_control()] documentation for
1011** additional information.
1014** No longer in use.
1016** <li>[[SQLITE_FCNTL_SYNC]]
1017** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
1018** sent to the VFS immediately before the xSync method is invoked on a
1019** database file descriptor. Or, if the xSync method is not invoked
1020** because the user has configured SQLite with
1021** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
1022** of the xSync method. In most cases, the pointer argument passed with
1023** this file-control is NULL. However, if the database file is being synced
1024** as part of a multi-database commit, the argument points to a nul-terminated
1025** string containing the transactions master-journal file name. VFSes that
1026** do not need this signal should silently ignore this opcode. Applications
1027** should not call [sqlite3_file_control()] with this opcode as doing so may
1028** disrupt the operation of the specialized VFSes that do require it.
1031** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
1032** and sent to the VFS after a transaction has been committed immediately
1033** but before the database is unlocked. VFSes that do not need this signal
1034** should silently ignore this opcode. Applications should not call
1035** [sqlite3_file_control()] with this opcode as doing so may disrupt the
1036** operation of the specialized VFSes that do require it.
1038** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
1039** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
1040** retry counts and intervals for certain disk I/O operations for the
1041** windows [VFS] in order to provide robustness in the presence of
1042** anti-virus programs.  By default, the windows VFS will retry file read,
1043** file write, and file delete operations up to 10 times, with a delay
1044** of 25 milliseconds before the first retry and with the delay increasing
1045** by an additional 25 milliseconds with each subsequent retry.  This
1046** opcode allows these two values (10 retries and 25 milliseconds of delay)
1047** to be adjusted.  The values are changed for all database connections
1048** within the same process.  The argument is a pointer to an array of two
1049** integers where the first integer i the new retry count and the second
1050** integer is the delay.  If either integer is negative, then the setting
1051** is not changed but instead the prior value of that setting is written
1052** into the array entry, allowing the current retry settings to be
1053** interrogated.  The zDbName parameter is ignored.
1056** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
1057** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
1058** write ahead log and shared memory files used for transaction control
1059** are automatically deleted when the latest connection to the database
1060** closes.  Setting persistent WAL mode causes those files to persist after
1061** close.  Persisting the files is useful when other processes that do not
1062** have write permission on the directory containing the database file want
1063** to read the database file, as the WAL and shared memory files must exist
1064** in order for the database to be readable.  The fourth parameter to
1065** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
1066** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
1067** WAL mode.  If the integer is -1, then it is overwritten with the current
1068** WAL persistence setting.
1071** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
1072** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
1073** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
1074** xDeviceCharacteristics methods. The fourth parameter to
1075** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
1076** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
1077** mode.  If the integer is -1, then it is overwritten with the current
1078** zero-damage mode setting.
1081** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
1082** a write transaction to indicate that, unless it is rolled back for some
1083** reason, the entire database file will be overwritten by the current
1084** transaction. This is used by VACUUM operations.
1087** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1088** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
1089** final bottom-level VFS are written into memory obtained from
1090** [sqlite3_malloc()] and the result is stored in the char* variable
1091** that the fourth parameter of [sqlite3_file_control()] points to.
1092** The caller is responsible for freeing the memory when done.  As with
1093** all file-control actions, there is no guarantee that this will actually
1094** do anything.  Callers should initialize the char* variable to a NULL
1095** pointer in case this file-control is not implemented.  This file-control
1096** is intended for diagnostic use only.
1098** <li>[[SQLITE_FCNTL_PRAGMA]]
1099** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1100** file control is sent to the open [sqlite3_file] object corresponding
1101** to the database file to which the pragma statement refers. ^The argument
1102** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1103** pointers to strings (char**) in which the second element of the array
1104** is the name of the pragma and the third element is the argument to the
1105** pragma or NULL if the pragma has no argument.  ^The handler for an
1106** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1107** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1108** or the equivalent and that string will become the result of the pragma or
1109** the error message if the pragma fails. ^If the
1110** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1111** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
1112** file control returns [SQLITE_OK], then the parser assumes that the
1113** VFS has handled the PRAGMA itself and the parser generates a no-op
1114** prepared statement if result string is NULL, or that returns a copy
1115** of the result string if the string is non-NULL.
1116** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1117** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1118** that the VFS encountered an error while handling the [PRAGMA] and the
1119** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
1120** file control occurs at the beginning of pragma statement analysis and so
1121** it is able to override built-in [PRAGMA] statements.
1125** file-control may be invoked by SQLite on the database file handle
1126** shortly after it is opened in order to provide a custom VFS with access
1127** to the connections busy-handler callback. The argument is of type (void **)
1128** - an array of two (void *) values. The first (void *) actually points
1129** to a function of type (int (*)(void *)). In order to invoke the connections
1130** busy-handler, this function should be invoked with the second (void *) in
1131** the array as the only argument. If it returns non-zero, then the operation
1132** should be retried. If it returns zero, the custom VFS should abandon the
1133** current operation.
1136** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1137** to have SQLite generate a
1138** temporary filename using the same algorithm that is followed to generate
1139** temporary filenames for TEMP tables and other internal uses.  The
1140** argument should be a char** which will be filled with the filename
1141** written into memory obtained from [sqlite3_malloc()].  The caller should
1142** invoke [sqlite3_free()] on the result to avoid a memory leak.
1145** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1146** maximum number of bytes that will be used for memory-mapped I/O.
1147** The argument is a pointer to a value of type sqlite3_int64 that
1148** is an advisory maximum number of bytes in the file to memory map.  The
1149** pointer is overwritten with the old value.  The limit is not changed if
1150** the value originally pointed to is negative, and so the current limit
1151** can be queried by passing in a pointer to a negative number.  This
1152** file-control is used internally to implement [PRAGMA mmap_size].
1154** <li>[[SQLITE_FCNTL_TRACE]]
1155** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1156** to the VFS about what the higher layers of the SQLite stack are doing.
1157** This file control is used by some VFS activity tracing [shims].
1158** The argument is a zero-terminated string.  Higher layers in the
1159** SQLite stack may generate instances of this file control if
1160** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1163** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1164** pointer to an integer and it writes a boolean into that integer depending
1165** on whether or not the file has been renamed, moved, or deleted since it
1166** was first opened.
1169** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
1170** opcode causes the xFileControl method to swap the file handle with the one
1171** pointed to by the pArg argument.  This capability is used during testing
1172** and only needs to be supported when SQLITE_TEST is defined.
1175** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1176** be advantageous to block on the next WAL lock if the lock is not immediately
1177** available.  The WAL subsystem issues this signal during rare
1178** circumstances in order to fix a problem with priority inversion.
1179** Applications should <em>not</em> use this file-control.
1181** <li>[[SQLITE_FCNTL_ZIPVFS]]
1182** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1183** VFS should return SQLITE_NOTFOUND for this opcode.
1185** <li>[[SQLITE_FCNTL_RBU]]
1186** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1187** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
1188** this opcode.
1189** </ul>
1191#define SQLITE_FCNTL_LOCKSTATE               1
1194#define SQLITE_FCNTL_LAST_ERRNO              4
1195#define SQLITE_FCNTL_SIZE_HINT               5
1196#define SQLITE_FCNTL_CHUNK_SIZE              6
1197#define SQLITE_FCNTL_FILE_POINTER            7
1198#define SQLITE_FCNTL_SYNC_OMITTED            8
1199#define SQLITE_FCNTL_WIN32_AV_RETRY          9
1200#define SQLITE_FCNTL_PERSIST_WAL            10
1201#define SQLITE_FCNTL_OVERWRITE              11
1202#define SQLITE_FCNTL_VFSNAME                12
1204#define SQLITE_FCNTL_PRAGMA                 14
1205#define SQLITE_FCNTL_BUSYHANDLER            15
1206#define SQLITE_FCNTL_TEMPFILENAME           16
1207#define SQLITE_FCNTL_MMAP_SIZE              18
1208#define SQLITE_FCNTL_TRACE                  19
1209#define SQLITE_FCNTL_HAS_MOVED              20
1210#define SQLITE_FCNTL_SYNC                   21
1211#define SQLITE_FCNTL_COMMIT_PHASETWO        22
1212#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
1213#define SQLITE_FCNTL_WAL_BLOCK              24
1214#define SQLITE_FCNTL_ZIPVFS                 25
1215#define SQLITE_FCNTL_RBU                    26
1217/* deprecated names */
1224** CAPI3REF: Mutex Handle
1226** The mutex module within SQLite defines [sqlite3_mutex] to be an
1227** abstract type for a mutex object.  The SQLite core never looks
1228** at the internal representation of an [sqlite3_mutex].  It only
1229** deals with pointers to the [sqlite3_mutex] object.
1231** Mutexes are created using [sqlite3_mutex_alloc()].
1233typedef struct sqlite3_mutex sqlite3_mutex;
1236** CAPI3REF: OS Interface Object
1238** An instance of the sqlite3_vfs object defines the interface between
1239** the SQLite core and the underlying operating system.  The "vfs"
1240** in the name of the object stands for "virtual file system".  See
1241** the [VFS | VFS documentation] for further information.
1243** The value of the iVersion field is initially 1 but may be larger in
1244** future versions of SQLite.  Additional fields may be appended to this
1245** object when the iVersion value is increased.  Note that the structure
1246** of the sqlite3_vfs object changes in the transaction between
1247** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1248** modified.
1250** The szOsFile field is the size of the subclassed [sqlite3_file]
1251** structure used by this VFS.  mxPathname is the maximum length of
1252** a pathname in this VFS.
1254** Registered sqlite3_vfs objects are kept on a linked list formed by
1255** the pNext pointer.  The [sqlite3_vfs_register()]
1256** and [sqlite3_vfs_unregister()] interfaces manage this list
1257** in a thread-safe way.  The [sqlite3_vfs_find()] interface
1258** searches the list.  Neither the application code nor the VFS
1259** implementation should use the pNext pointer.
1261** The pNext field is the only field in the sqlite3_vfs
1262** structure that SQLite will ever modify.  SQLite will only access
1263** or modify this field while holding a particular static mutex.
1264** The application should never modify anything within the sqlite3_vfs
1265** object once the object has been registered.
1267** The zName field holds the name of the VFS module.  The name must
1268** be unique across all VFS modules.
1270** [[sqlite3_vfs.xOpen]]
1271** ^SQLite guarantees that the zFilename parameter to xOpen
1272** is either a NULL pointer or string obtained
1273** from xFullPathname() with an optional suffix added.
1274** ^If a suffix is added to the zFilename parameter, it will
1275** consist of a single "-" character followed by no more than
1276** 11 alphanumeric and/or "-" characters.
1277** ^SQLite further guarantees that
1278** the string will be valid and unchanged until xClose() is
1279** called. Because of the previous sentence,
1280** the [sqlite3_file] can safely store a pointer to the
1281** filename if it needs to remember the filename for some reason.
1282** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1283** must invent its own temporary name for the file.  ^Whenever the
1284** xFilename parameter is NULL it will also be the case that the
1285** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1287** The flags argument to xOpen() includes all bits set in
1288** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
1289** or [sqlite3_open16()] is used, then flags includes at least
1291** If xOpen() opens a file read-only then it sets *pOutFlags to
1292** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
1294** ^(SQLite will also add one of the following flags to the xOpen()
1295** call, depending on the object being opened:
1297** <ul>
1298** <li>  [SQLITE_OPEN_MAIN_DB]
1300** <li>  [SQLITE_OPEN_TEMP_DB]
1305** <li>  [SQLITE_OPEN_WAL]
1306** </ul>)^
1308** The file I/O implementation can use the object type flags to
1309** change the way it deals with files.  For example, an application
1310** that does not care about crash recovery or rollback might make
1311** the open of a journal file a no-op.  Writes to this journal would
1312** also be no-ops, and any attempt to read the journal would return
1313** SQLITE_IOERR.  Or the implementation might recognize that a database
1314** file will be doing page-aligned sector reads and writes in a random
1315** order and set up its I/O subsystem accordingly.
1317** SQLite might also add one of the following flags to the xOpen method:
1319** <ul>
1322** </ul>
1324** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1325** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
1326** will be set for TEMP databases and their journals, transient
1327** databases, and subjournals.
1329** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1330** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1331** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1332** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1333** SQLITE_OPEN_CREATE, is used to indicate that file should always
1334** be created, and that it is an error if it already exists.
1335** It is <i>not</i> used to indicate the file should be opened
1336** for exclusive access.
1338** ^At least szOsFile bytes of memory are allocated by SQLite
1339** to hold the  [sqlite3_file] structure passed as the third
1340** argument to xOpen.  The xOpen method does not have to
1341** allocate the structure; it should just fill it in.  Note that
1342** the xOpen method must set the sqlite3_file.pMethods to either
1343** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
1344** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
1345** element will be valid after xOpen returns regardless of the success
1346** or failure of the xOpen call.
1348** [[sqlite3_vfs.xAccess]]
1349** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1350** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1351** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1352** to test whether a file is at least readable.   The file can be a
1353** directory.
1355** ^SQLite will always allocate at least mxPathname+1 bytes for the
1356** output buffer xFullPathname.  The exact size of the output buffer
1357** is also passed as a parameter to both  methods. If the output buffer
1358** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1359** handled as a fatal error by SQLite, vfs implementations should endeavor
1360** to prevent this by setting mxPathname to a sufficiently large value.
1362** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1363** interfaces are not strictly a part of the filesystem, but they are
1364** included in the VFS structure for completeness.
1365** The xRandomness() function attempts to return nBytes bytes
1366** of good-quality randomness into zOut.  The return value is
1367** the actual number of bytes of randomness obtained.
1368** The xSleep() method causes the calling thread to sleep for at
1369** least the number of microseconds given.  ^The xCurrentTime()
1370** method returns a Julian Day Number for the current date and time as
1371** a floating point value.
1372** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1373** Day Number multiplied by 86400000 (the number of milliseconds in
1374** a 24-hour day).
1375** ^SQLite will use the xCurrentTimeInt64() method to get the current
1376** date and time if that method is available (if iVersion is 2 or
1377** greater and the function pointer is not NULL) and will fall back
1378** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1380** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1381** are not used by the SQLite core.  These optional interfaces are provided
1382** by some VFSes to facilitate testing of the VFS code. By overriding
1383** system calls with functions under its control, a test program can
1384** simulate faults and error conditions that would otherwise be difficult
1385** or impossible to induce.  The set of system calls that can be overridden
1386** varies from one VFS to another, and from one version of the same VFS to the
1387** next.  Applications that use these interfaces must be prepared for any
1388** or all of these interfaces to be NULL or for their behavior to change
1389** from one release to the next.  Applications must not attempt to access
1390** any of these methods if the iVersion of the VFS is less than 3.
1392typedef struct sqlite3_vfs sqlite3_vfs;
1393typedef void (*sqlite3_syscall_ptr)(void);
1394struct sqlite3_vfs {
1395  int iVersion;            /* Structure version number (currently 3) */
1396  int szOsFile;            /* Size of subclassed sqlite3_file */
1397  int mxPathname;          /* Maximum file pathname length */
1398  sqlite3_vfs *pNext;      /* Next registered VFS */
1399  const char *zName;       /* Name of this virtual file system */
1400  void *pAppData;          /* Pointer to application-specific data */
1401  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1402               int flags, int *pOutFlags);
1403  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1404  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1405  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1406  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1407  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1408  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1409  void (*xDlClose)(sqlite3_vfs*, void*);
1410  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1411  int (*xSleep)(sqlite3_vfs*, int microseconds);
1412  int (*xCurrentTime)(sqlite3_vfs*, double*);
1413  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1414  /*
1415  ** The methods above are in version 1 of the sqlite_vfs object
1416  ** definition.  Those that follow are added in version 2 or later
1417  */
1418  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1419  /*
1420  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1421  ** Those below are for version 3 and greater.
1422  */
1423  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1424  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1425  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1426  /*
1427  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1428  ** New fields may be appended in figure versions.  The iVersion
1429  ** value will increment whenever this happens.
1430  */
1434** CAPI3REF: Flags for the xAccess VFS method
1436** These integer constants can be used as the third parameter to
1437** the xAccess method of an [sqlite3_vfs] object.  They determine
1438** what kind of permissions the xAccess method is looking for.
1439** With SQLITE_ACCESS_EXISTS, the xAccess method
1440** simply checks whether the file exists.
1441** With SQLITE_ACCESS_READWRITE, the xAccess method
1442** checks whether the named directory is both readable and writable
1443** (in other words, if files can be added, removed, and renamed within
1444** the directory).
1445** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1446** [temp_store_directory pragma], though this could change in a future
1447** release of SQLite.
1448** With SQLITE_ACCESS_READ, the xAccess method
1449** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
1450** currently unused, though it might be used in a future release of
1451** SQLite.
1453#define SQLITE_ACCESS_EXISTS    0
1454#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
1455#define SQLITE_ACCESS_READ      2   /* Unused */
1458** CAPI3REF: Flags for the xShmLock VFS method
1460** These integer constants define the various locking operations
1461** allowed by the xShmLock method of [sqlite3_io_methods].  The
1462** following are the only legal combinations of flags to the
1463** xShmLock method:
1465** <ul>
1470** </ul>
1472** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1473** was given on the corresponding lock.
1475** The xShmLock method can transition between unlocked and SHARED or
1476** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
1477** and EXCLUSIVE.
1479#define SQLITE_SHM_UNLOCK       1
1480#define SQLITE_SHM_LOCK         2
1481#define SQLITE_SHM_SHARED       4
1482#define SQLITE_SHM_EXCLUSIVE    8
1485** CAPI3REF: Maximum xShmLock index
1487** The xShmLock method on [sqlite3_io_methods] may use values
1488** between 0 and this upper bound as its "offset" argument.
1489** The SQLite core will never attempt to acquire or release a
1490** lock outside of this range
1492#define SQLITE_SHM_NLOCK        8
1496** CAPI3REF: Initialize The SQLite Library
1498** ^The sqlite3_initialize() routine initializes the
1499** SQLite library.  ^The sqlite3_shutdown() routine
1500** deallocates any resources that were allocated by sqlite3_initialize().
1501** These routines are designed to aid in process initialization and
1502** shutdown on embedded systems.  Workstation applications using
1503** SQLite normally do not need to invoke either of these routines.
1505** A call to sqlite3_initialize() is an "effective" call if it is
1506** the first time sqlite3_initialize() is invoked during the lifetime of
1507** the process, or if it is the first time sqlite3_initialize() is invoked
1508** following a call to sqlite3_shutdown().  ^(Only an effective call
1509** of sqlite3_initialize() does any initialization.  All other calls
1510** are harmless no-ops.)^
1512** A call to sqlite3_shutdown() is an "effective" call if it is the first
1513** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
1514** an effective call to sqlite3_shutdown() does any deinitialization.
1515** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1517** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1518** is not.  The sqlite3_shutdown() interface must only be called from a
1519** single thread.  All open [database connections] must be closed and all
1520** other SQLite resources must be deallocated prior to invoking
1521** sqlite3_shutdown().
1523** Among other things, ^sqlite3_initialize() will invoke
1524** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
1525** will invoke sqlite3_os_end().
1527** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1528** ^If for some reason, sqlite3_initialize() is unable to initialize
1529** the library (perhaps it is unable to allocate a needed resource such
1530** as a mutex) it returns an [error code] other than [SQLITE_OK].
1532** ^The sqlite3_initialize() routine is called internally by many other
1533** SQLite interfaces so that an application usually does not need to
1534** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
1535** calls sqlite3_initialize() so the SQLite library will be automatically
1536** initialized when [sqlite3_open()] is called if it has not be initialized
1537** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1538** compile-time option, then the automatic calls to sqlite3_initialize()
1539** are omitted and the application must call sqlite3_initialize() directly
1540** prior to using any other SQLite interface.  For maximum portability,
1541** it is recommended that applications always invoke sqlite3_initialize()
1542** directly prior to using any other SQLite interface.  Future releases
1543** of SQLite may require this.  In other words, the behavior exhibited
1544** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1545** default behavior in some future release of SQLite.
1547** The sqlite3_os_init() routine does operating-system specific
1548** initialization of the SQLite library.  The sqlite3_os_end()
1549** routine undoes the effect of sqlite3_os_init().  Typical tasks
1550** performed by these routines include allocation or deallocation
1551** of static resources, initialization of global variables,
1552** setting up a default [sqlite3_vfs] module, or setting up
1553** a default configuration using [sqlite3_config()].
1555** The application should never invoke either sqlite3_os_init()
1556** or sqlite3_os_end() directly.  The application should only invoke
1557** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
1558** interface is called automatically by sqlite3_initialize() and
1559** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
1560** implementations for sqlite3_os_init() and sqlite3_os_end()
1561** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1562** When [custom builds | built for other platforms]
1563** (using the [SQLITE_OS_OTHER=1] compile-time
1564** option) the application must supply a suitable implementation for
1565** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
1566** implementation of sqlite3_os_init() or sqlite3_os_end()
1567** must return [SQLITE_OK] on success and some other [error code] upon
1568** failure.
1570SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void);
1571SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void);
1572SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void);
1573SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void);
1576** CAPI3REF: Configuring The SQLite Library
1578** The sqlite3_config() interface is used to make global configuration
1579** changes to SQLite in order to tune SQLite to the specific needs of
1580** the application.  The default configuration is recommended for most
1581** applications and so this routine is usually not necessary.  It is
1582** provided to support rare applications with unusual needs.
1584** <b>The sqlite3_config() interface is not threadsafe. The application
1585** must ensure that no other SQLite interfaces are invoked by other
1586** threads while sqlite3_config() is running.</b>
1588** The sqlite3_config() interface
1589** may only be invoked prior to library initialization using
1590** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1591** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1592** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1593** Note, however, that ^sqlite3_config() can be called as part of the
1594** implementation of an application-defined [sqlite3_os_init()].
1596** The first argument to sqlite3_config() is an integer
1597** [configuration option] that determines
1598** what property of SQLite is to be configured.  Subsequent arguments
1599** vary depending on the [configuration option]
1600** in the first argument.
1602** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1603** ^If the option is unknown or SQLite is unable to set the option
1604** then this routine returns a non-zero [error code].
1606SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...);
1609** CAPI3REF: Configure database connections
1610** METHOD: sqlite3
1612** The sqlite3_db_config() interface is used to make configuration
1613** changes to a [database connection].  The interface is similar to
1614** [sqlite3_config()] except that the changes apply to a single
1615** [database connection] (specified in the first argument).
1617** The second argument to sqlite3_db_config(D,V,...)  is the
1618** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1619** that indicates what aspect of the [database connection] is being configured.
1620** Subsequent arguments vary depending on the configuration verb.
1622** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1623** the call is considered successful.
1625SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...);
1628** CAPI3REF: Memory Allocation Routines
1630** An instance of this object defines the interface between SQLite
1631** and low-level memory allocation routines.
1633** This object is used in only one place in the SQLite interface.
1634** A pointer to an instance of this object is the argument to
1635** [sqlite3_config()] when the configuration option is
1637** By creating an instance of this object
1638** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1639** during configuration, an application can specify an alternative
1640** memory allocation subsystem for SQLite to use for all of its
1641** dynamic memory needs.
1643** Note that SQLite comes with several [built-in memory allocators]
1644** that are perfectly adequate for the overwhelming majority of applications
1645** and that this object is only useful to a tiny minority of applications
1646** with specialized memory allocation requirements.  This object is
1647** also used during testing of SQLite in order to specify an alternative
1648** memory allocator that simulates memory out-of-memory conditions in
1649** order to verify that SQLite recovers gracefully from such
1650** conditions.
1652** The xMalloc, xRealloc, and xFree methods must work like the
1653** malloc(), realloc() and free() functions from the standard C library.
1654** ^SQLite guarantees that the second argument to
1655** xRealloc is always a value returned by a prior call to xRoundup.
1657** xSize should return the allocated size of a memory allocation
1658** previously obtained from xMalloc or xRealloc.  The allocated size
1659** is always at least as big as the requested size but may be larger.
1661** The xRoundup method returns what would be the allocated size of
1662** a memory allocation given a particular requested size.  Most memory
1663** allocators round up memory allocations at least to the next multiple
1664** of 8.  Some allocators round up to a larger multiple or to a power of 2.
1665** Every memory allocation request coming in through [sqlite3_malloc()]
1666** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
1667** that causes the corresponding memory allocation to fail.
1669** The xInit method initializes the memory allocator.  For example,
1670** it might allocate any require mutexes or initialize internal data
1671** structures.  The xShutdown method is invoked (indirectly) by
1672** [sqlite3_shutdown()] and should deallocate any resources acquired
1673** by xInit.  The pAppData pointer is used as the only parameter to
1674** xInit and xShutdown.
1676** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1677** the xInit method, so the xInit method need not be threadsafe.  The
1678** xShutdown method is only called from [sqlite3_shutdown()] so it does
1679** not need to be threadsafe either.  For all other methods, SQLite
1680** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1681** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1682** it is by default) and so the methods are automatically serialized.
1683** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1684** methods must be threadsafe or else make their own arrangements for
1685** serialization.
1687** SQLite will never invoke xInit() more than once without an intervening
1688** call to xShutdown().
1690typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1691struct sqlite3_mem_methods {
1692  void *(*xMalloc)(int);         /* Memory allocation function */
1693  void (*xFree)(void*);          /* Free a prior allocation */
1694  void *(*xRealloc)(void*,int);  /* Resize an allocation */
1695  int (*xSize)(void*);           /* Return the size of an allocation */
1696  int (*xRoundup)(int);          /* Round up request size to allocation size */
1697  int (*xInit)(void*);           /* Initialize the memory allocator */
1698  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
1699  void *pAppData;                /* Argument to xInit() and xShutdown() */
1703** CAPI3REF: Configuration Options
1704** KEYWORDS: {configuration option}
1706** These constants are the available integer configuration options that
1707** can be passed as the first argument to the [sqlite3_config()] interface.
1709** New configuration options may be added in future releases of SQLite.
1710** Existing configuration options might be discontinued.  Applications
1711** should check the return code from [sqlite3_config()] to make sure that
1712** the call worked.  The [sqlite3_config()] interface will return a
1713** non-zero [error code] if a discontinued or unsupported configuration option
1714** is invoked.
1716** <dl>
1718** <dd>There are no arguments to this option.  ^This option sets the
1719** [threading mode] to Single-thread.  In other words, it disables
1720** all mutexing and puts SQLite into a mode where it can only be used
1721** by a single thread.   ^If SQLite is compiled with
1722** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1723** it is not possible to change the [threading mode] from its default
1724** value of Single-thread and so [sqlite3_config()] will return
1726** configuration option.</dd>
1729** <dd>There are no arguments to this option.  ^This option sets the
1730** [threading mode] to Multi-thread.  In other words, it disables
1731** mutexing on [database connection] and [prepared statement] objects.
1732** The application is responsible for serializing access to
1733** [database connections] and [prepared statements].  But other mutexes
1734** are enabled so that SQLite will be safe to use in a multi-threaded
1735** environment as long as no two threads attempt to use the same
1736** [database connection] at the same time.  ^If SQLite is compiled with
1737** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1738** it is not possible to set the Multi-thread [threading mode] and
1739** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1740** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1743** <dd>There are no arguments to this option.  ^This option sets the
1744** [threading mode] to Serialized. In other words, this option enables
1745** all mutexes including the recursive
1746** mutexes on [database connection] and [prepared statement] objects.
1747** In this mode (which is the default when SQLite is compiled with
1748** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1749** to [database connections] and [prepared statements] so that the
1750** application is free to use the same [database connection] or the
1751** same [prepared statement] in different threads at the same time.
1752** ^If SQLite is compiled with
1753** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1754** it is not possible to set the Serialized [threading mode] and
1755** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1756** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1759** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1760** a pointer to an instance of the [sqlite3_mem_methods] structure.
1761** The argument specifies
1762** alternative low-level memory allocation routines to be used in place of
1763** the memory allocation routines built into SQLite.)^ ^SQLite makes
1764** its own private copy of the content of the [sqlite3_mem_methods] structure
1765** before the [sqlite3_config()] call returns.</dd>
1768** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1769** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1770** The [sqlite3_mem_methods]
1771** structure is filled with the currently defined memory allocation routines.)^
1772** This option can be used to overload the default memory allocation
1773** routines with a wrapper that simulations memory allocation failure or
1774** tracks memory usage, for example. </dd>
1777** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1778** interpreted as a boolean, which enables or disables the collection of
1779** memory allocation statistics. ^(When memory allocation statistics are
1780** disabled, the following SQLite interfaces become non-operational:
1781**   <ul>
1782**   <li> [sqlite3_memory_used()]
1783**   <li> [sqlite3_memory_highwater()]
1784**   <li> [sqlite3_soft_heap_limit64()]
1785**   <li> [sqlite3_status64()]
1786**   </ul>)^
1787** ^Memory allocation statistics are enabled by default unless SQLite is
1788** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1789** allocation statistics are disabled by default.
1790** </dd>
1793** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
1794** that SQLite can use for scratch memory.  ^(There are three arguments
1795** to SQLITE_CONFIG_SCRATCH:  A pointer an 8-byte
1796** aligned memory buffer from which the scratch allocations will be
1797** drawn, the size of each scratch allocation (sz),
1798** and the maximum number of scratch allocations (N).)^
1799** The first argument must be a pointer to an 8-byte aligned buffer
1800** of at least sz*N bytes of memory.
1801** ^SQLite will not use more than one scratch buffers per thread.
1802** ^SQLite will never request a scratch buffer that is more than 6
1803** times the database page size.
1804** ^If SQLite needs needs additional
1805** scratch memory beyond what is provided by this configuration option, then
1806** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
1807** ^When the application provides any amount of scratch memory using
1808** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
1809** [sqlite3_malloc|heap allocations].
1810** This can help [Robson proof|prevent memory allocation failures] due to heap
1811** fragmentation in low-memory embedded systems.
1812** </dd>
1815** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer
1816** that SQLite can use for the database page cache with the default page
1817** cache implementation.
1818** This configuration should not be used if an application-define page
1819** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]
1820** configuration option.
1821** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1822** 8-byte aligned
1823** memory, the size of each page buffer (sz), and the number of pages (N).
1824** The sz argument should be the size of the largest database page
1825** (a power of two between 512 and 65536) plus some extra bytes for each
1826** page header.  ^The number of extra bytes needed by the page header
1827** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option
1828** to [sqlite3_config()].
1829** ^It is harmless, apart from the wasted memory,
1830** for the sz parameter to be larger than necessary.  The first
1831** argument should pointer to an 8-byte aligned block of memory that
1832** is at least sz*N bytes of memory, otherwise subsequent behavior is
1833** undefined.
1834** ^SQLite will use the memory provided by the first argument to satisfy its
1835** memory needs for the first N pages that it adds to cache.  ^If additional
1836** page cache memory is needed beyond what is provided by this option, then
1837** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd>
1840** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1841** that SQLite will use for all of its dynamic memory allocation needs
1842** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
1844** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1845** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1846** [SQLITE_ERROR] if invoked otherwise.
1847** ^There are three arguments to SQLITE_CONFIG_HEAP:
1848** An 8-byte aligned pointer to the memory,
1849** the number of bytes in the memory buffer, and the minimum allocation size.
1850** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1851** to using its default memory allocator (the system malloc() implementation),
1852** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
1853** memory pointer is not NULL then the alternative memory
1854** allocator is engaged to handle all of SQLites memory allocation needs.
1855** The first pointer (the memory pointer) must be aligned to an 8-byte
1856** boundary or subsequent behavior of SQLite will be undefined.
1857** The minimum allocation size is capped at 2**12. Reasonable values
1858** for the minimum allocation size are 2**5 through 2**8.</dd>
1861** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1862** pointer to an instance of the [sqlite3_mutex_methods] structure.
1863** The argument specifies alternative low-level mutex routines to be used
1864** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
1865** the content of the [sqlite3_mutex_methods] structure before the call to
1866** [sqlite3_config()] returns. ^If SQLite is compiled with
1867** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1868** the entire mutexing subsystem is omitted from the build and hence calls to
1869** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1870** return [SQLITE_ERROR].</dd>
1873** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1874** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
1875** [sqlite3_mutex_methods]
1876** structure is filled with the currently defined mutex routines.)^
1877** This option can be used to overload the default mutex allocation
1878** routines with a wrapper used to track mutex usage for performance
1879** profiling or testing, for example.   ^If SQLite is compiled with
1880** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1881** the entire mutexing subsystem is omitted from the build and hence calls to
1882** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1883** return [SQLITE_ERROR].</dd>
1886** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1887** the default size of lookaside memory on each [database connection].
1888** The first argument is the
1889** size of each lookaside buffer slot and the second is the number of
1890** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
1891** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1892** option to [sqlite3_db_config()] can be used to change the lookaside
1893** configuration on individual connections.)^ </dd>
1896** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1897** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
1898** the interface to a custom page cache implementation.)^
1899** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1902** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1903** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
1904** the current page cache implementation into that object.)^ </dd>
1907** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1908** global [error log].
1909** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1910** function with a call signature of void(*)(void*,int,const char*),
1911** and a pointer to void. ^If the function pointer is not NULL, it is
1912** invoked by [sqlite3_log()] to process each logging event.  ^If the
1913** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1914** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1915** passed through as the first parameter to the application-defined logger
1916** function whenever that function is invoked.  ^The second parameter to
1917** the logger function is a copy of the first parameter to the corresponding
1918** [sqlite3_log()] call and is intended to be a [result code] or an
1919** [extended result code].  ^The third parameter passed to the logger is
1920** log message after formatting via [sqlite3_snprintf()].
1921** The SQLite logging interface is not reentrant; the logger function
1922** supplied by the application must not invoke any SQLite interface.
1923** In a multi-threaded application, the application-defined logger
1924** function must be threadsafe. </dd>
1927** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1928** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1929** then URI handling is globally disabled.)^ ^If URI handling is globally
1930** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1931** [sqlite3_open16()] or
1932** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1933** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1934** connection is opened. ^If it is globally disabled, filenames are
1935** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1936** database connection is opened. ^(By default, URI handling is globally
1937** disabled. The default value may be changed by compiling with the
1938** [SQLITE_USE_URI] symbol defined.)^
1941** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1942** argument which is interpreted as a boolean in order to enable or disable
1943** the use of covering indices for full table scans in the query optimizer.
1944** ^The default setting is determined
1945** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1946** if that compile-time option is omitted.
1947** The ability to disable the use of covering indices for full table scans
1948** is because some incorrectly coded legacy applications might malfunction
1949** when the optimization is enabled.  Providing the ability to
1950** disable the optimization allows the older, buggy application code to work
1951** without change even with newer versions of SQLite.
1955** <dd> These options are obsolete and should not be used by new code.
1956** They are retained for backwards compatibility but are now no-ops.
1957** </dd>
1961** <dd>This option is only available if sqlite is compiled with the
1962** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1963** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1964** The second should be of type (void*). The callback is invoked by the library
1965** in three separate circumstances, identified by the value passed as the
1966** fourth parameter. If the fourth parameter is 0, then the database connection
1967** passed as the second argument has just been opened. The third argument
1968** points to a buffer containing the name of the main database file. If the
1969** fourth parameter is 1, then the SQL statement that the third parameter
1970** points to has just been executed. Or, if the fourth parameter is 2, then
1971** the connection being passed as the second parameter is being closed. The
1972** third parameter is passed NULL In this case.  An example of using this
1973** configuration option can be seen in the "test_sqllog.c" source file in
1974** the canonical SQLite source tree.</dd>
1978** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1979** that are the default mmap size limit (the default setting for
1980** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1981** ^The default setting can be overridden by each database connection using
1982** either the [PRAGMA mmap_size] command, or by using the
1983** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
1984** will be silently truncated if necessary so that it does not exceed the
1985** compile-time maximum mmap size set by the
1986** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1987** ^If either argument to this option is negative, then that argument is
1988** changed to its compile-time default.
1992** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1993** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1994** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1995** that specifies the maximum size of the created heap.
1999** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2000** is a pointer to an integer and writes into that integer the number of extra
2001** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2002** The amount of extra space required can change depending on the compiler,
2003** target platform, and SQLite version.
2007** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2008** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2009** sorter to that integer.  The default minimum PMA Size is set by the
2010** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
2011** to help with sort operations when multithreaded sorting
2012** is enabled (using the [PRAGMA threads] command) and the amount of content
2013** to be sorted exceeds the page size times the minimum of the
2014** [PRAGMA cache_size] setting and this value.
2015** </dl>
2017#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
2018#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
2019#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
2020#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
2021#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
2022#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
2023#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
2024#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
2025#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
2026#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
2027#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
2028/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2029#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
2030#define SQLITE_CONFIG_PCACHE       14  /* no-op */
2031#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
2032#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
2033#define SQLITE_CONFIG_URI          17  /* int */
2034#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
2035#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
2036#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
2037#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
2038#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
2039#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
2040#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
2041#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
2044** CAPI3REF: Database Connection Configuration Options
2046** These constants are the available integer configuration options that
2047** can be passed as the second argument to the [sqlite3_db_config()] interface.
2049** New configuration options may be added in future releases of SQLite.
2050** Existing configuration options might be discontinued.  Applications
2051** should check the return code from [sqlite3_db_config()] to make sure that
2052** the call worked.  ^The [sqlite3_db_config()] interface will return a
2053** non-zero [error code] if a discontinued or unsupported configuration option
2054** is invoked.
2056** <dl>
2058** <dd> ^This option takes three additional arguments that determine the
2059** [lookaside memory allocator] configuration for the [database connection].
2060** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2061** pointer to a memory buffer to use for lookaside memory.
2062** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2063** may be NULL in which case SQLite will allocate the
2064** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2065** size of each lookaside buffer slot.  ^The third argument is the number of
2066** slots.  The size of the buffer in the first argument must be greater than
2067** or equal to the product of the second and third arguments.  The buffer
2068** must be aligned to an 8-byte boundary.  ^If the second argument to
2069** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2070** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
2071** configuration for a database connection can only be changed when that
2072** connection is not currently using lookaside memory, or in other words
2073** when the "current value" returned by
2074** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2075** Any attempt to change the lookaside memory configuration when lookaside
2076** memory is in use leaves the configuration unchanged and returns
2077** [SQLITE_BUSY].)^</dd>
2080** <dd> ^This option is used to enable or disable the enforcement of
2081** [foreign key constraints].  There should be two additional arguments.
2082** The first argument is an integer which is 0 to disable FK enforcement,
2083** positive to enable FK enforcement or negative to leave FK enforcement
2084** unchanged.  The second parameter is a pointer to an integer into which
2085** is written 0 or 1 to indicate whether FK enforcement is off or on
2086** following this call.  The second parameter may be a NULL pointer, in
2087** which case the FK enforcement setting is not reported back. </dd>
2090** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2091** There should be two additional arguments.
2092** The first argument is an integer which is 0 to disable triggers,
2093** positive to enable triggers or negative to leave the setting unchanged.
2094** The second parameter is a pointer to an integer into which
2095** is written 0 or 1 to indicate whether triggers are disabled or enabled
2096** following this call.  The second parameter may be a NULL pointer, in
2097** which case the trigger setting is not reported back. </dd>
2099** </dl>
2101#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
2102#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
2103#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
2107** CAPI3REF: Enable Or Disable Extended Result Codes
2108** METHOD: sqlite3
2110** ^The sqlite3_extended_result_codes() routine enables or disables the
2111** [extended result codes] feature of SQLite. ^The extended result
2112** codes are disabled by default for historical compatibility.
2114SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff);
2117** CAPI3REF: Last Insert Rowid
2118** METHOD: sqlite3
2120** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2121** has a unique 64-bit signed
2122** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2123** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2124** names are not also used by explicitly declared columns. ^If
2125** the table has a column of type [INTEGER PRIMARY KEY] then that column
2126** is another alias for the rowid.
2128** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
2129** most recent successful [INSERT] into a rowid table or [virtual table]
2130** on database connection D.
2131** ^Inserts into [WITHOUT ROWID] tables are not recorded.
2132** ^If no successful [INSERT]s into rowid tables
2133** have ever occurred on the database connection D,
2134** then sqlite3_last_insert_rowid(D) returns zero.
2136** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
2137** method, then this routine will return the [rowid] of the inserted
2138** row as long as the trigger or virtual table method is running.
2139** But once the trigger or virtual table method ends, the value returned
2140** by this routine reverts to what it was before the trigger or virtual
2141** table method began.)^
2143** ^An [INSERT] that fails due to a constraint violation is not a
2144** successful [INSERT] and does not change the value returned by this
2146** and INSERT OR ABORT make no changes to the return value of this
2147** routine when their insertion fails.  ^(When INSERT OR REPLACE
2148** encounters a constraint violation, it does not fail.  The
2149** INSERT continues to completion after deleting rows that caused
2150** the constraint problem so INSERT OR REPLACE will always change
2151** the return value of this interface.)^
2153** ^For the purposes of this routine, an [INSERT] is considered to
2154** be successful even if it is subsequently rolled back.
2156** This function is accessible to SQL statements via the
2157** [last_insert_rowid() SQL function].
2159** If a separate thread performs a new [INSERT] on the same
2160** database connection while the [sqlite3_last_insert_rowid()]
2161** function is running and thus changes the last insert [rowid],
2162** then the value returned by [sqlite3_last_insert_rowid()] is
2163** unpredictable and might not equal either the old or the new
2164** last insert [rowid].
2166SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*);
2169** CAPI3REF: Count The Number Of Rows Modified
2170** METHOD: sqlite3
2172** ^This function returns the number of rows modified, inserted or
2173** deleted by the most recently completed INSERT, UPDATE or DELETE
2174** statement on the database connection specified by the only parameter.
2175** ^Executing any other type of SQL statement does not modify the value
2176** returned by this function.
2178** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2179** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2180** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2182** Changes to a view that are intercepted by
2183** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2184** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2185** DELETE statement run on a view is always zero. Only changes made to real
2186** tables are counted.
2188** Things are more complicated if the sqlite3_changes() function is
2189** executed while a trigger program is running. This may happen if the
2190** program uses the [changes() SQL function], or if some other callback
2191** function invokes sqlite3_changes() directly. Essentially:
2193** <ul>
2194**   <li> ^(Before entering a trigger program the value returned by
2195**        sqlite3_changes() function is saved. After the trigger program
2196**        has finished, the original value is restored.)^
2198**   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2199**        statement sets the value returned by sqlite3_changes()
2200**        upon completion as normal. Of course, this value will not include
2201**        any changes performed by sub-triggers, as the sqlite3_changes()
2202**        value will be saved and restored after each sub-trigger has run.)^
2203** </ul>
2205** ^This means that if the changes() SQL function (or similar) is used
2206** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2207** returns the value as set when the calling statement began executing.
2208** ^If it is used by the second or subsequent such statement within a trigger
2209** program, the value returned reflects the number of rows modified by the
2210** previous INSERT, UPDATE or DELETE statement within the same trigger.
2212** See also the [sqlite3_total_changes()] interface, the
2213** [count_changes pragma], and the [changes() SQL function].
2215** If a separate thread makes changes on the same database connection
2216** while [sqlite3_changes()] is running then the value returned
2217** is unpredictable and not meaningful.
2219SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*);
2222** CAPI3REF: Total Number Of Rows Modified
2223** METHOD: sqlite3
2225** ^This function returns the total number of rows inserted, modified or
2226** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2227** since the database connection was opened, including those executed as
2228** part of trigger programs. ^Executing any other type of SQL statement
2229** does not affect the value returned by sqlite3_total_changes().
2231** ^Changes made as part of [foreign key actions] are included in the
2232** count, but those made as part of REPLACE constraint resolution are
2233** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2234** are not counted.
2236** See also the [sqlite3_changes()] interface, the
2237** [count_changes pragma], and the [total_changes() SQL function].
2239** If a separate thread makes changes on the same database connection
2240** while [sqlite3_total_changes()] is running then the value
2241** returned is unpredictable and not meaningful.
2243SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*);
2246** CAPI3REF: Interrupt A Long-Running Query
2247** METHOD: sqlite3
2249** ^This function causes any pending database operation to abort and
2250** return at its earliest opportunity. This routine is typically
2251** called in response to a user action such as pressing "Cancel"
2252** or Ctrl-C where the user wants a long query operation to halt
2253** immediately.
2255** ^It is safe to call this routine from a thread different from the
2256** thread that is currently running the database operation.  But it
2257** is not safe to call this routine with a [database connection] that
2258** is closed or might close before sqlite3_interrupt() returns.
2260** ^If an SQL operation is very nearly finished at the time when
2261** sqlite3_interrupt() is called, then it might not have an opportunity
2262** to be interrupted and might continue to completion.
2264** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2265** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2266** that is inside an explicit transaction, then the entire transaction
2267** will be rolled back automatically.
2269** ^The sqlite3_interrupt(D) call is in effect until all currently running
2270** SQL statements on [database connection] D complete.  ^Any new SQL statements
2271** that are started after the sqlite3_interrupt() call and before the
2272** running statements reaches zero are interrupted as if they had been
2273** running prior to the sqlite3_interrupt() call.  ^New SQL statements
2274** that are started after the running statement count reaches zero are
2275** not effected by the sqlite3_interrupt().
2276** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2277** SQL statements is a no-op and has no effect on SQL statements
2278** that are started after the sqlite3_interrupt() call returns.
2280** If the database connection closes while [sqlite3_interrupt()]
2281** is running then bad things will likely happen.
2283SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*);
2286** CAPI3REF: Determine If An SQL Statement Is Complete
2288** These routines are useful during command-line input to determine if the
2289** currently entered text seems to form a complete SQL statement or
2290** if additional input is needed before sending the text into
2291** SQLite for parsing.  ^These routines return 1 if the input string
2292** appears to be a complete SQL statement.  ^A statement is judged to be
2293** complete if it ends with a semicolon token and is not a prefix of a
2294** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
2295** string literals or quoted identifier names or comments are not
2296** independent tokens (they are part of the token in which they are
2297** embedded) and thus do not count as a statement terminator.  ^Whitespace
2298** and comments that follow the final semicolon are ignored.
2300** ^These routines return 0 if the statement is incomplete.  ^If a
2301** memory allocation fails, then SQLITE_NOMEM is returned.
2303** ^These routines do not parse the SQL statements thus
2304** will not detect syntactically incorrect SQL.
2306** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2307** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2308** automatically by sqlite3_complete16().  If that initialization fails,
2309** then the return value from sqlite3_complete16() will be non-zero
2310** regardless of whether or not the input SQL is complete.)^
2312** The input to [sqlite3_complete()] must be a zero-terminated
2313** UTF-8 string.
2315** The input to [sqlite3_complete16()] must be a zero-terminated
2316** UTF-16 string in native byte order.
2318SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql);
2319SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql);
2322** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2323** KEYWORDS: {busy-handler callback} {busy handler}
2324** METHOD: sqlite3
2326** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2327** that might be invoked with argument P whenever
2328** an attempt is made to access a database table associated with
2329** [database connection] D when another thread
2330** or process has the table locked.
2331** The sqlite3_busy_handler() interface is used to implement
2332** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2334** ^If the busy callback is NULL, then [SQLITE_BUSY]
2335** is returned immediately upon encountering the lock.  ^If the busy callback
2336** is not NULL, then the callback might be invoked with two arguments.
2338** ^The first argument to the busy handler is a copy of the void* pointer which
2339** is the third argument to sqlite3_busy_handler().  ^The second argument to
2340** the busy handler callback is the number of times that the busy handler has
2341** been invoked previously for the same locking event.  ^If the
2342** busy callback returns 0, then no additional attempts are made to
2343** access the database and [SQLITE_BUSY] is returned
2344** to the application.
2345** ^If the callback returns non-zero, then another attempt
2346** is made to access the database and the cycle repeats.
2348** The presence of a busy handler does not guarantee that it will be invoked
2349** when there is lock contention. ^If SQLite determines that invoking the busy
2350** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2351** to the application instead of invoking the
2352** busy handler.
2353** Consider a scenario where one process is holding a read lock that
2354** it is trying to promote to a reserved lock and
2355** a second process is holding a reserved lock that it is trying
2356** to promote to an exclusive lock.  The first process cannot proceed
2357** because it is blocked by the second and the second process cannot
2358** proceed because it is blocked by the first.  If both processes
2359** invoke the busy handlers, neither will make any progress.  Therefore,
2360** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2361** will induce the first process to release its read lock and allow
2362** the second process to proceed.
2364** ^The default busy callback is NULL.
2366** ^(There can only be a single busy handler defined for each
2367** [database connection].  Setting a new busy handler clears any
2368** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
2369** or evaluating [PRAGMA busy_timeout=N] will change the
2370** busy handler and thus clear any previously set busy handler.
2372** The busy callback should not take any actions which modify the
2373** database connection that invoked the busy handler.  In other words,
2374** the busy handler is not reentrant.  Any such actions
2375** result in undefined behavior.
2377** A busy handler must not close the database connection
2378** or [prepared statement] that invoked the busy handler.
2380SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2383** CAPI3REF: Set A Busy Timeout
2384** METHOD: sqlite3
2386** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2387** for a specified amount of time when a table is locked.  ^The handler
2388** will sleep multiple times until at least "ms" milliseconds of sleeping
2389** have accumulated.  ^After at least "ms" milliseconds of sleeping,
2390** the handler returns 0 which causes [sqlite3_step()] to return
2391** [SQLITE_BUSY].
2393** ^Calling this routine with an argument less than or equal to zero
2394** turns off all busy handlers.
2396** ^(There can only be a single busy handler for a particular
2397** [database connection] at any given moment.  If another busy handler
2398** was defined  (using [sqlite3_busy_handler()]) prior to calling
2399** this routine, that other busy handler is cleared.)^
2401** See also:  [PRAGMA busy_timeout]
2403SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms);
2406** CAPI3REF: Convenience Routines For Running Queries
2407** METHOD: sqlite3
2409** This is a legacy interface that is preserved for backwards compatibility.
2410** Use of this interface is not recommended.
2412** Definition: A <b>result table</b> is memory data structure created by the
2413** [sqlite3_get_table()] interface.  A result table records the
2414** complete query results from one or more queries.
2416** The table conceptually has a number of rows and columns.  But
2417** these numbers are not part of the result table itself.  These
2418** numbers are obtained separately.  Let N be the number of rows
2419** and M be the number of columns.
2421** A result table is an array of pointers to zero-terminated UTF-8 strings.
2422** There are (N+1)*M elements in the array.  The first M pointers point
2423** to zero-terminated strings that  contain the names of the columns.
2424** The remaining entries all point to query results.  NULL values result
2425** in NULL pointers.  All other values are in their UTF-8 zero-terminated
2426** string representation as returned by [sqlite3_column_text()].
2428** A result table might consist of one or more memory allocations.
2429** It is not safe to pass a result table directly to [sqlite3_free()].
2430** A result table should be deallocated using [sqlite3_free_table()].
2432** ^(As an example of the result table format, suppose a query result
2433** is as follows:
2435** <blockquote><pre>
2436**        Name        | Age
2437**        -----------------------
2438**        Alice       | 43
2439**        Bob         | 28
2440**        Cindy       | 21
2441** </pre></blockquote>
2443** There are two column (M==2) and three rows (N==3).  Thus the
2444** result table has 8 entries.  Suppose the result table is stored
2445** in an array names azResult.  Then azResult holds this content:
2447** <blockquote><pre>
2448**        azResult&#91;0] = "Name";
2449**        azResult&#91;1] = "Age";
2450**        azResult&#91;2] = "Alice";
2451**        azResult&#91;3] = "43";
2452**        azResult&#91;4] = "Bob";
2453**        azResult&#91;5] = "28";
2454**        azResult&#91;6] = "Cindy";
2455**        azResult&#91;7] = "21";
2456** </pre></blockquote>)^
2458** ^The sqlite3_get_table() function evaluates one or more
2459** semicolon-separated SQL statements in the zero-terminated UTF-8
2460** string of its 2nd parameter and returns a result table to the
2461** pointer given in its 3rd parameter.
2463** After the application has finished with the result from sqlite3_get_table(),
2464** it must pass the result table pointer to sqlite3_free_table() in order to
2465** release the memory that was malloced.  Because of the way the
2466** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2467** function must not try to call [sqlite3_free()] directly.  Only
2468** [sqlite3_free_table()] is able to release the memory properly and safely.
2470** The sqlite3_get_table() interface is implemented as a wrapper around
2471** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
2472** to any internal data structures of SQLite.  It uses only the public
2473** interface defined here.  As a consequence, errors that occur in the
2474** wrapper layer outside of the internal [sqlite3_exec()] call are not
2475** reflected in subsequent calls to [sqlite3_errcode()] or
2476** [sqlite3_errmsg()].
2478SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
2479  sqlite3 *db,          /* An open database */
2480  const char *zSql,     /* SQL to be evaluated */
2481  char ***pazResult,    /* Results of the query */
2482  int *pnRow,           /* Number of result rows written here */
2483  int *pnColumn,        /* Number of result columns written here */
2484  char **pzErrmsg       /* Error msg written here */
2486SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result);
2489** CAPI3REF: Formatted String Printing Functions
2491** These routines are work-alikes of the "printf()" family of functions
2492** from the standard C library.
2493** These routines understand most of the common K&R formatting options,
2494** plus some additional non-standard formats, detailed below.
2495** Note that some of the more obscure formatting options from recent
2496** C-library standards are omitted from this implementation.
2498** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2499** results into memory obtained from [sqlite3_malloc()].
2500** The strings returned by these two routines should be
2501** released by [sqlite3_free()].  ^Both routines return a
2502** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2503** memory to hold the resulting string.
2505** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2506** the standard C library.  The result is written into the
2507** buffer supplied as the second parameter whose size is given by
2508** the first parameter. Note that the order of the
2509** first two parameters is reversed from snprintf().)^  This is an
2510** historical accident that cannot be fixed without breaking
2511** backwards compatibility.  ^(Note also that sqlite3_snprintf()
2512** returns a pointer to its buffer instead of the number of
2513** characters actually written into the buffer.)^  We admit that
2514** the number of characters written would be a more useful return
2515** value but we cannot change the implementation of sqlite3_snprintf()
2516** now without breaking compatibility.
2518** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2519** guarantees that the buffer is always zero-terminated.  ^The first
2520** parameter "n" is the total size of the buffer, including space for
2521** the zero terminator.  So the longest string that can be completely
2522** written will be n-1 characters.
2524** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2526** These routines all implement some additional formatting
2527** options that are useful for constructing SQL statements.
2528** All of the usual printf() formatting options apply.  In addition, there
2529** is are "%q", "%Q", "%w" and "%z" options.
2531** ^(The %q option works like %s in that it substitutes a nul-terminated
2532** string from the argument list.  But %q also doubles every '\'' character.
2533** %q is designed for use inside a string literal.)^  By doubling each '\''
2534** character it escapes that character and allows it to be inserted into
2535** the string.
2537** For example, assume the string variable zText contains text as follows:
2539** <blockquote><pre>
2540**  char *zText = "It's a happy day!";
2541** </pre></blockquote>
2543** One can use this text in an SQL statement as follows:
2545** <blockquote><pre>
2546**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2547**  sqlite3_exec(db, zSQL, 0, 0, 0);
2548**  sqlite3_free(zSQL);
2549** </pre></blockquote>
2551** Because the %q format string is used, the '\'' character in zText
2552** is escaped and the SQL generated is as follows:
2554** <blockquote><pre>
2555**  INSERT INTO table1 VALUES('It''s a happy day!')
2556** </pre></blockquote>
2558** This is correct.  Had we used %s instead of %q, the generated SQL
2559** would have looked like this:
2561** <blockquote><pre>
2562**  INSERT INTO table1 VALUES('It's a happy day!');
2563** </pre></blockquote>
2565** This second example is an SQL syntax error.  As a general rule you should
2566** always use %q instead of %s when inserting text into a string literal.
2568** ^(The %Q option works like %q except it also adds single quotes around
2569** the outside of the total string.  Additionally, if the parameter in the
2570** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2571** single quotes).)^  So, for example, one could say:
2573** <blockquote><pre>
2574**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2575**  sqlite3_exec(db, zSQL, 0, 0, 0);
2576**  sqlite3_free(zSQL);
2577** </pre></blockquote>
2579** The code above will render a correct SQL statement in the zSQL
2580** variable even if the zText variable is a NULL pointer.
2582** ^(The "%w" formatting option is like "%q" except that it expects to
2583** be contained within double-quotes instead of single quotes, and it
2584** escapes the double-quote character instead of the single-quote
2585** character.)^  The "%w" formatting option is intended for safely inserting
2586** table and column names into a constructed SQL statement.
2588** ^(The "%z" formatting option works like "%s" but with the
2589** addition that after the string has been read and copied into
2590** the result, [sqlite3_free()] is called on the input string.)^
2592SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...);
2593SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list);
2594SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...);
2595SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list);
2598** CAPI3REF: Memory Allocation Subsystem
2600** The SQLite core uses these three routines for all of its own
2601** internal memory allocation needs. "Core" in the previous sentence
2602** does not include operating-system specific VFS implementation.  The
2603** Windows VFS uses native malloc() and free() for some operations.
2605** ^The sqlite3_malloc() routine returns a pointer to a block
2606** of memory at least N bytes in length, where N is the parameter.
2607** ^If sqlite3_malloc() is unable to obtain sufficient free
2608** memory, it returns a NULL pointer.  ^If the parameter N to
2609** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2610** a NULL pointer.
2612** ^The sqlite3_malloc64(N) routine works just like
2613** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2614** of a signed 32-bit integer.
2616** ^Calling sqlite3_free() with a pointer previously returned
2617** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2618** that it might be reused.  ^The sqlite3_free() routine is
2619** a no-op if is called with a NULL pointer.  Passing a NULL pointer
2620** to sqlite3_free() is harmless.  After being freed, memory
2621** should neither be read nor written.  Even reading previously freed
2622** memory might result in a segmentation fault or other severe error.
2623** Memory corruption, a segmentation fault, or other severe error
2624** might result if sqlite3_free() is called with a non-NULL pointer that
2625** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2627** ^The sqlite3_realloc(X,N) interface attempts to resize a
2628** prior memory allocation X to be at least N bytes.
2629** ^If the X parameter to sqlite3_realloc(X,N)
2630** is a NULL pointer then its behavior is identical to calling
2631** sqlite3_malloc(N).
2632** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2633** negative then the behavior is exactly the same as calling
2634** sqlite3_free(X).
2635** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2636** of at least N bytes in size or NULL if insufficient memory is available.
2637** ^If M is the size of the prior allocation, then min(N,M) bytes
2638** of the prior allocation are copied into the beginning of buffer returned
2639** by sqlite3_realloc(X,N) and the prior allocation is freed.
2640** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2641** prior allocation is not freed.
2643** ^The sqlite3_realloc64(X,N) interfaces works the same as
2644** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2645** of a 32-bit signed integer.
2647** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2648** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2649** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2650** ^The value returned by sqlite3_msize(X) might be larger than the number
2651** of bytes requested when X was allocated.  ^If X is a NULL pointer then
2652** sqlite3_msize(X) returns zero.  If X points to something that is not
2653** the beginning of memory allocation, or if it points to a formerly
2654** valid memory allocation that has now been freed, then the behavior
2655** of sqlite3_msize(X) is undefined and possibly harmful.
2657** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2658** sqlite3_malloc64(), and sqlite3_realloc64()
2659** is always aligned to at least an 8 byte boundary, or to a
2660** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2661** option is used.
2663** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2664** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2665** implementation of these routines to be omitted.  That capability
2666** is no longer provided.  Only built-in memory allocators can be used.
2668** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2669** the system malloc() and free() directly when converting
2670** filenames between the UTF-8 encoding used by SQLite
2671** and whatever filename encoding is used by the particular Windows
2672** installation.  Memory allocation errors were detected, but
2673** they were reported back as [SQLITE_CANTOPEN] or
2674** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2676** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2677** must be either NULL or else pointers obtained from a prior
2678** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2679** not yet been released.
2681** The application must not read or write any part of
2682** a block of memory after it has been released using
2683** [sqlite3_free()] or [sqlite3_realloc()].
2685SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int);
2686SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64);
2687SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int);
2688SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64);
2689SQLITE_API void SQLITE_STDCALL sqlite3_free(void*);
2690SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*);
2693** CAPI3REF: Memory Allocator Statistics
2695** SQLite provides these two interfaces for reporting on the status
2696** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2697** routines, which form the built-in memory allocation subsystem.
2699** ^The [sqlite3_memory_used()] routine returns the number of bytes
2700** of memory currently outstanding (malloced but not freed).
2701** ^The [sqlite3_memory_highwater()] routine returns the maximum
2702** value of [sqlite3_memory_used()] since the high-water mark
2703** was last reset.  ^The values returned by [sqlite3_memory_used()] and
2704** [sqlite3_memory_highwater()] include any overhead
2705** added by SQLite in its implementation of [sqlite3_malloc()],
2706** but not overhead added by the any underlying system library
2707** routines that [sqlite3_malloc()] may call.
2709** ^The memory high-water mark is reset to the current value of
2710** [sqlite3_memory_used()] if and only if the parameter to
2711** [sqlite3_memory_highwater()] is true.  ^The value returned
2712** by [sqlite3_memory_highwater(1)] is the high-water mark
2713** prior to the reset.
2715SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void);
2716SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag);
2719** CAPI3REF: Pseudo-Random Number Generator
2721** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2722** select random [ROWID | ROWIDs] when inserting new records into a table that
2723** already uses the largest possible [ROWID].  The PRNG is also used for
2724** the build-in random() and randomblob() SQL functions.  This interface allows
2725** applications to access the same PRNG for other purposes.
2727** ^A call to this routine stores N bytes of randomness into buffer P.
2728** ^The P parameter can be a NULL pointer.
2730** ^If this routine has not been previously called or if the previous
2731** call had N less than one or a NULL pointer for P, then the PRNG is
2732** seeded using randomness obtained from the xRandomness method of
2733** the default [sqlite3_vfs] object.
2734** ^If the previous call to this routine had an N of 1 or more and a
2735** non-NULL P then the pseudo-randomness is generated
2736** internally and without recourse to the [sqlite3_vfs] xRandomness
2737** method.
2739SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P);
2742** CAPI3REF: Compile-Time Authorization Callbacks
2743** METHOD: sqlite3
2745** ^This routine registers an authorizer callback with a particular
2746** [database connection], supplied in the first argument.
2747** ^The authorizer callback is invoked as SQL statements are being compiled
2748** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2749** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
2750** points during the compilation process, as logic is being created
2751** to perform various actions, the authorizer callback is invoked to
2752** see if those actions are allowed.  ^The authorizer callback should
2753** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2754** specific action but allow the SQL statement to continue to be
2755** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2756** rejected with an error.  ^If the authorizer callback returns
2757** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2758** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2759** the authorizer will fail with an error message.
2761** When the callback returns [SQLITE_OK], that means the operation
2762** requested is ok.  ^When the callback returns [SQLITE_DENY], the
2763** [sqlite3_prepare_v2()] or equivalent call that triggered the
2764** authorizer will fail with an error message explaining that
2765** access is denied.
2767** ^The first parameter to the authorizer callback is a copy of the third
2768** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2769** to the callback is an integer [SQLITE_COPY | action code] that specifies
2770** the particular action to be authorized. ^The third through sixth parameters
2771** to the callback are zero-terminated strings that contain additional
2772** details about the action to be authorized.
2774** ^If the action code is [SQLITE_READ]
2775** and the callback returns [SQLITE_IGNORE] then the
2776** [prepared statement] statement is constructed to substitute
2777** a NULL value in place of the table column that would have
2778** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
2779** return can be used to deny an untrusted user access to individual
2780** columns of a table.
2781** ^If the action code is [SQLITE_DELETE] and the callback returns
2782** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2783** [truncate optimization] is disabled and all rows are deleted individually.
2785** An authorizer is used when [sqlite3_prepare | preparing]
2786** SQL statements from an untrusted source, to ensure that the SQL statements
2787** do not try to access data they are not allowed to see, or that they do not
2788** try to execute malicious statements that damage the database.  For
2789** example, an application may allow a user to enter arbitrary
2790** SQL queries for evaluation by a database.  But the application does
2791** not want the user to be able to make arbitrary changes to the
2792** database.  An authorizer could then be put in place while the
2793** user-entered SQL is being [sqlite3_prepare | prepared] that
2794** disallows everything except [SELECT] statements.
2796** Applications that need to process SQL from untrusted sources
2797** might also consider lowering resource limits using [sqlite3_limit()]
2798** and limiting database size using the [max_page_count] [PRAGMA]
2799** in addition to using an authorizer.
2801** ^(Only a single authorizer can be in place on a database connection
2802** at a time.  Each call to sqlite3_set_authorizer overrides the
2803** previous call.)^  ^Disable the authorizer by installing a NULL callback.
2804** The authorizer is disabled by default.
2806** The authorizer callback must not do anything that will modify
2807** the database connection that invoked the authorizer callback.
2808** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2809** database connections for the meaning of "modify" in this paragraph.
2811** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2812** statement might be re-prepared during [sqlite3_step()] due to a
2813** schema change.  Hence, the application should ensure that the
2814** correct authorizer callback remains in place during the [sqlite3_step()].
2816** ^Note that the authorizer callback is invoked only during
2817** [sqlite3_prepare()] or its variants.  Authorization is not
2818** performed during statement evaluation in [sqlite3_step()], unless
2819** as stated in the previous paragraph, sqlite3_step() invokes
2820** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2822SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
2823  sqlite3*,
2824  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2825  void *pUserData
2829** CAPI3REF: Authorizer Return Codes
2831** The [sqlite3_set_authorizer | authorizer callback function] must
2832** return either [SQLITE_OK] or one of these two constants in order
2833** to signal SQLite whether or not the action is permitted.  See the
2834** [sqlite3_set_authorizer | authorizer documentation] for additional
2835** information.
2837** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2838** returned from the [sqlite3_vtab_on_conflict()] interface.
2840#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
2841#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
2844** CAPI3REF: Authorizer Action Codes
2846** The [sqlite3_set_authorizer()] interface registers a callback function
2847** that is invoked to authorize certain SQL statement actions.  The
2848** second parameter to the callback is an integer code that specifies
2849** what action is being authorized.  These are the integer action codes that
2850** the authorizer callback may be passed.
2852** These action code values signify what kind of operation is to be
2853** authorized.  The 3rd and 4th parameters to the authorization
2854** callback function will be parameters or NULL depending on which of these
2855** codes is used as the second parameter.  ^(The 5th parameter to the
2856** authorizer callback is the name of the database ("main", "temp",
2857** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
2858** is the name of the inner-most trigger or view that is responsible for
2859** the access attempt or NULL if this access attempt is directly from
2860** top-level SQL code.
2862/******************************************* 3rd ************ 4th ***********/
2863#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
2864#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
2865#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
2866#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
2867#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
2868#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
2869#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
2870#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
2871#define SQLITE_DELETE                9   /* Table Name      NULL            */
2872#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
2873#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
2874#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
2875#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
2876#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
2877#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
2878#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
2879#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
2880#define SQLITE_INSERT               18   /* Table Name      NULL            */
2881#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
2882#define SQLITE_READ                 20   /* Table Name      Column Name     */
2883#define SQLITE_SELECT               21   /* NULL            NULL            */
2884#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
2885#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
2886#define SQLITE_ATTACH               24   /* Filename        NULL            */
2887#define SQLITE_DETACH               25   /* Database Name   NULL            */
2888#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
2889#define SQLITE_REINDEX              27   /* Index Name      NULL            */
2890#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
2891#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
2892#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
2893#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
2894#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
2895#define SQLITE_COPY                  0   /* No longer used */
2896#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
2899** CAPI3REF: Tracing And Profiling Functions
2900** METHOD: sqlite3
2902** These routines register callback functions that can be used for
2903** tracing and profiling the execution of SQL statements.
2905** ^The callback function registered by sqlite3_trace() is invoked at
2906** various times when an SQL statement is being run by [sqlite3_step()].
2907** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2908** SQL statement text as the statement first begins executing.
2909** ^(Additional sqlite3_trace() callbacks might occur
2910** as each triggered subprogram is entered.  The callbacks for triggers
2911** contain a UTF-8 SQL comment that identifies the trigger.)^
2913** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2914** the length of [bound parameter] expansion in the output of sqlite3_trace().
2916** ^The callback function registered by sqlite3_profile() is invoked
2917** as each SQL statement finishes.  ^The profile callback contains
2918** the original statement text and an estimate of wall-clock time
2919** of how long that statement took to run.  ^The profile callback
2920** time is in units of nanoseconds, however the current implementation
2921** is only capable of millisecond resolution so the six least significant
2922** digits in the time are meaningless.  Future versions of SQLite
2923** might provide greater resolution on the profiler callback.  The
2924** sqlite3_profile() function is considered experimental and is
2925** subject to change in future versions of SQLite.
2927SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2928SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*,
2929   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2932** CAPI3REF: Query Progress Callbacks
2933** METHOD: sqlite3
2935** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2936** function X to be invoked periodically during long running calls to
2937** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2938** database connection D.  An example use for this
2939** interface is to keep a GUI updated during a large query.
2941** ^The parameter P is passed through as the only parameter to the
2942** callback function X.  ^The parameter N is the approximate number of
2943** [virtual machine instructions] that are evaluated between successive
2944** invocations of the callback X.  ^If N is less than one then the progress
2945** handler is disabled.
2947** ^Only a single progress handler may be defined at one time per
2948** [database connection]; setting a new progress handler cancels the
2949** old one.  ^Setting parameter X to NULL disables the progress handler.
2950** ^The progress handler is also disabled by setting N to a value less
2951** than 1.
2953** ^If the progress callback returns non-zero, the operation is
2954** interrupted.  This feature can be used to implement a
2955** "Cancel" button on a GUI progress dialog box.
2957** The progress handler callback must not do anything that will modify
2958** the database connection that invoked the progress handler.
2959** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2960** database connections for the meaning of "modify" in this paragraph.
2963SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2966** CAPI3REF: Opening A New Database Connection
2967** CONSTRUCTOR: sqlite3
2969** ^These routines open an SQLite database file as specified by the
2970** filename argument. ^The filename argument is interpreted as UTF-8 for
2971** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2972** order for sqlite3_open16(). ^(A [database connection] handle is usually
2973** returned in *ppDb, even if an error occurs.  The only exception is that
2974** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2975** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2976** object.)^ ^(If the database is opened (and/or created) successfully, then
2977** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
2978** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2979** an English language description of the error following a failure of any
2980** of the sqlite3_open() routines.
2982** ^The default encoding will be UTF-8 for databases created using
2983** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases
2984** created using sqlite3_open16() will be UTF-16 in the native byte order.
2986** Whether or not an error occurs when it is opened, resources
2987** associated with the [database connection] handle should be released by
2988** passing it to [sqlite3_close()] when it is no longer required.
2990** The sqlite3_open_v2() interface works like sqlite3_open()
2991** except that it accepts two additional parameters for additional control
2992** over the new database connection.  ^(The flags parameter to
2993** sqlite3_open_v2() can take one of
2994** the following three values, optionally combined with the
2998** <dl>
2999** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3000** <dd>The database is opened in read-only mode.  If the database does not
3001** already exist, an error is returned.</dd>)^
3003** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3004** <dd>The database is opened for reading and writing if possible, or reading
3005** only if the file is write protected by the operating system.  In either
3006** case the database must already exist, otherwise an error is returned.</dd>)^
3009** <dd>The database is opened for reading and writing, and is created if
3010** it does not already exist. This is the behavior that is always used for
3011** sqlite3_open() and sqlite3_open16().</dd>)^
3012** </dl>
3014** If the 3rd parameter to sqlite3_open_v2() is not one of the
3015** combinations shown above optionally combined with other
3017** then the behavior is undefined.
3019** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3020** opens in the multi-thread [threading mode] as long as the single-thread
3021** mode has not been set at compile-time or start-time.  ^If the
3022** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3023** in the serialized [threading mode] unless single-thread was
3024** previously selected at compile-time or start-time.
3025** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3026** eligible to use [shared cache mode], regardless of whether or not shared
3027** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
3028** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3029** participate in [shared cache mode] even if it is enabled.
3031** ^The fourth parameter to sqlite3_open_v2() is the name of the
3032** [sqlite3_vfs] object that defines the operating system interface that
3033** the new database connection should use.  ^If the fourth parameter is
3034** a NULL pointer then the default [sqlite3_vfs] object is used.
3036** ^If the filename is ":memory:", then a private, temporary in-memory database
3037** is created for the connection.  ^This in-memory database will vanish when
3038** the database connection is closed.  Future versions of SQLite might
3039** make use of additional special filenames that begin with the ":" character.
3040** It is recommended that when a database filename actually does begin with
3041** a ":" character you should prefix the filename with a pathname such as
3042** "./" to avoid ambiguity.
3044** ^If the filename is an empty string, then a private, temporary
3045** on-disk database will be created.  ^This private database will be
3046** automatically deleted as soon as the database connection is closed.
3048** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3050** ^If [URI filename] interpretation is enabled, and the filename argument
3051** begins with "file:", then the filename is interpreted as a URI. ^URI
3052** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3053** set in the fourth argument to sqlite3_open_v2(), or if it has
3054** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3055** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3056** As of SQLite version 3.7.7, URI filename interpretation is turned off
3057** by default, but future releases of SQLite might enable URI filename
3058** interpretation by default.  See "[URI filenames]" for additional
3059** information.
3061** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3062** authority, then it must be either an empty string or the string
3063** "localhost". ^If the authority is not an empty string or "localhost", an
3064** error is returned to the caller. ^The fragment component of a URI, if
3065** present, is ignored.
3067** ^SQLite uses the path component of the URI as the name of the disk file
3068** which contains the database. ^If the path begins with a '/' character,
3069** then it is interpreted as an absolute path. ^If the path does not begin
3070** with a '/' (meaning that the authority section is omitted from the URI)
3071** then the path is interpreted as a relative path.
3072** ^(On windows, the first component of an absolute path
3073** is a drive specification (e.g. "C:").)^
3075** [[core URI query parameters]]
3076** The query component of a URI may contain parameters that are interpreted
3077** either by SQLite itself, or by a [VFS | custom VFS implementation].
3078** SQLite and its built-in [VFSes] interpret the
3079** following query parameters:
3081** <ul>
3082**   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3083**     a VFS object that provides the operating system interface that should
3084**     be used to access the database file on disk. ^If this option is set to
3085**     an empty string the default VFS object is used. ^Specifying an unknown
3086**     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3087**     present, then the VFS specified by the option takes precedence over
3088**     the value passed as the fourth parameter to sqlite3_open_v2().
3090**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3091**     "rwc", or "memory". Attempting to set it to any other value is
3092**     an error)^.
3093**     ^If "ro" is specified, then the database is opened for read-only
3094**     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3095**     third argument to sqlite3_open_v2(). ^If the mode option is set to
3096**     "rw", then the database is opened for read-write (but not create)
3097**     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3098**     been set. ^Value "rwc" is equivalent to setting both
3099**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
3100**     set to "memory" then a pure [in-memory database] that never reads
3101**     or writes from disk is used. ^It is an error to specify a value for
3102**     the mode parameter that is less restrictive than that specified by
3103**     the flags passed in the third parameter to sqlite3_open_v2().
3105**   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3106**     "private". ^Setting it to "shared" is equivalent to setting the
3107**     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3108**     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3109**     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3110**     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3111**     a URI filename, its value overrides any behavior requested by setting
3114**  <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3115**     [powersafe overwrite] property does or does not apply to the
3116**     storage media on which the database file resides.
3118**  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3119**     which if set disables file locking in rollback journal modes.  This
3120**     is useful for accessing a database on a filesystem that does not
3121**     support locking.  Caution:  Database corruption might result if two
3122**     or more processes write to the same database and any one of those
3123**     processes uses nolock=1.
3125**  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3126**     parameter that indicates that the database file is stored on
3127**     read-only media.  ^When immutable is set, SQLite assumes that the
3128**     database file cannot be changed, even by a process with higher
3129**     privilege, and so the database is opened read-only and all locking
3130**     and change detection is disabled.  Caution: Setting the immutable
3131**     property on a database file that does in fact change can result
3132**     in incorrect query results and/or [SQLITE_CORRUPT] errors.
3133**     See also: [SQLITE_IOCAP_IMMUTABLE].
3135** </ul>
3137** ^Specifying an unknown parameter in the query component of a URI is not an
3138** error.  Future versions of SQLite might understand additional query
3139** parameters.  See "[query parameters with special meaning to SQLite]" for
3140** additional information.
3142** [[URI filename examples]] <h3>URI filename examples</h3>
3144** <table border="1" align=center cellpadding=5>
3145** <tr><th> URI filenames <th> Results
3146** <tr><td> file:data.db <td>
3147**          Open the file "data.db" in the current directory.
3148** <tr><td> file:/home/fred/data.db<br>
3149**          file:///home/fred/data.db <br>
3150**          file://localhost/home/fred/data.db <br> <td>
3151**          Open the database file "/home/fred/data.db".
3152** <tr><td> file://darkstar/home/fred/data.db <td>
3153**          An error. "darkstar" is not a recognized authority.
3154** <tr><td style="white-space:nowrap">
3155**          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3156**     <td> Windows only: Open the file "data.db" on fred's desktop on drive
3157**          C:. Note that the %20 escaping in this example is not strictly
3158**          necessary - space characters can be used literally
3159**          in URI filenames.
3160** <tr><td> file:data.db?mode=ro&cache=private <td>
3161**          Open file "data.db" in the current directory for read-only access.
3162**          Regardless of whether or not shared-cache mode is enabled by
3163**          default, use a private cache.
3164** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3165**          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3166**          that uses dot-files in place of posix advisory locking.
3167** <tr><td> file:data.db?mode=readonly <td>
3168**          An error. "readonly" is not a valid option for the "mode" parameter.
3169** </table>
3171** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3172** query components of a URI. A hexadecimal escape sequence consists of a
3173** percent sign - "%" - followed by exactly two hexadecimal digits
3174** specifying an octet value. ^Before the path or query components of a
3175** URI filename are interpreted, they are encoded using UTF-8 and all
3176** hexadecimal escape sequences replaced by a single byte containing the
3177** corresponding octet. If this process generates an invalid UTF-8 encoding,
3178** the results are undefined.
3180** <b>Note to Windows users:</b>  The encoding used for the filename argument
3181** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3182** codepage is currently defined.  Filenames containing international
3183** characters must be converted to UTF-8 prior to passing them into
3184** sqlite3_open() or sqlite3_open_v2().
3186** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
3187** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
3188** features that require the use of temporary files may fail.
3190** See also: [sqlite3_temp_directory]
3192SQLITE_API int SQLITE_STDCALL sqlite3_open(
3193  const char *filename,   /* Database filename (UTF-8) */
3194  sqlite3 **ppDb          /* OUT: SQLite db handle */
3196SQLITE_API int SQLITE_STDCALL sqlite3_open16(
3197  const void *filename,   /* Database filename (UTF-16) */
3198  sqlite3 **ppDb          /* OUT: SQLite db handle */
3200SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
3201  const char *filename,   /* Database filename (UTF-8) */
3202  sqlite3 **ppDb,         /* OUT: SQLite db handle */
3203  int flags,              /* Flags */
3204  const char *zVfs        /* Name of VFS module to use */
3208** CAPI3REF: Obtain Values For URI Parameters
3210** These are utility routines, useful to VFS implementations, that check
3211** to see if a database file was a URI that contained a specific query
3212** parameter, and if so obtains the value of that query parameter.
3214** If F is the database filename pointer passed into the xOpen() method of
3215** a VFS implementation when the flags parameter to xOpen() has one or
3216** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3217** P is the name of the query parameter, then
3218** sqlite3_uri_parameter(F,P) returns the value of the P
3219** parameter if it exists or a NULL pointer if P does not appear as a
3220** query parameter on F.  If P is a query parameter of F
3221** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3222** a pointer to an empty string.
3224** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3225** parameter and returns true (1) or false (0) according to the value
3226** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3227** value of query parameter P is one of "yes", "true", or "on" in any
3228** case or if the value begins with a non-zero number.  The
3229** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3230** query parameter P is one of "no", "false", or "off" in any case or
3231** if the value begins with a numeric zero.  If P is not a query
3232** parameter on F or if the value of P is does not match any of the
3233** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3235** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3236** 64-bit signed integer and returns that integer, or D if P does not
3237** exist.  If the value of P is something other than an integer, then
3238** zero is returned.
3240** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3241** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
3242** is not a database file pathname pointer that SQLite passed into the xOpen
3243** VFS method, then the behavior of this routine is undefined and probably
3244** undesirable.
3246SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3247SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3248SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3252** CAPI3REF: Error Codes And Messages
3253** METHOD: sqlite3
3255** ^If the most recent sqlite3_* API call associated with
3256** [database connection] D failed, then the sqlite3_errcode(D) interface
3257** returns the numeric [result code] or [extended result code] for that
3258** API call.
3259** If the most recent API call was successful,
3260** then the return value from sqlite3_errcode() is undefined.
3261** ^The sqlite3_extended_errcode()
3262** interface is the same except that it always returns the
3263** [extended result code] even when extended result codes are
3264** disabled.
3266** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3267** text that describes the error, as either UTF-8 or UTF-16 respectively.
3268** ^(Memory to hold the error message string is managed internally.
3269** The application does not need to worry about freeing the result.
3270** However, the error string might be overwritten or deallocated by
3271** subsequent calls to other SQLite interface functions.)^
3273** ^The sqlite3_errstr() interface returns the English-language text
3274** that describes the [result code], as UTF-8.
3275** ^(Memory to hold the error message string is managed internally
3276** and must not be freed by the application)^.
3278** When the serialized [threading mode] is in use, it might be the
3279** case that a second error occurs on a separate thread in between
3280** the time of the first error and the call to these interfaces.
3281** When that happens, the second error will be reported since these
3282** interfaces always report the most recent result.  To avoid
3283** this, each thread can obtain exclusive use of the [database connection] D
3284** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3285** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3286** all calls to the interfaces listed here are completed.
3288** If an interface fails with SQLITE_MISUSE, that means the interface
3289** was invoked incorrectly by the application.  In that case, the
3290** error code and message may or may not be set.
3292SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db);
3293SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db);
3294SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*);
3295SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*);
3296SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int);
3299** CAPI3REF: Prepared Statement Object
3300** KEYWORDS: {prepared statement} {prepared statements}
3302** An instance of this object represents a single SQL statement that
3303** has been compiled into binary form and is ready to be evaluated.
3305** Think of each SQL statement as a separate computer program.  The
3306** original SQL text is source code.  A prepared statement object
3307** is the compiled object code.  All SQL must be converted into a
3308** prepared statement before it can be run.
3310** The life-cycle of a prepared statement object usually goes like this:
3312** <ol>
3313** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3314** <li> Bind values to [parameters] using the sqlite3_bind_*()
3315**      interfaces.
3316** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3317** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3318**      to step 2.  Do this zero or more times.
3319** <li> Destroy the object using [sqlite3_finalize()].
3320** </ol>
3322typedef struct sqlite3_stmt sqlite3_stmt;
3325** CAPI3REF: Run-time Limits
3326** METHOD: sqlite3
3328** ^(This interface allows the size of various constructs to be limited
3329** on a connection by connection basis.  The first parameter is the
3330** [database connection] whose limit is to be set or queried.  The
3331** second parameter is one of the [limit categories] that define a
3332** class of constructs to be size limited.  The third parameter is the
3333** new limit for that construct.)^
3335** ^If the new limit is a negative number, the limit is unchanged.
3336** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3337** [limits | hard upper bound]
3338** set at compile-time by a C preprocessor macro called
3339** [limits | SQLITE_MAX_<i>NAME</i>].
3340** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3341** ^Attempts to increase a limit above its hard upper bound are
3342** silently truncated to the hard upper bound.
3344** ^Regardless of whether or not the limit was changed, the
3345** [sqlite3_limit()] interface returns the prior value of the limit.
3346** ^Hence, to find the current value of a limit without changing it,
3347** simply invoke this interface with the third parameter set to -1.
3349** Run-time limits are intended for use in applications that manage
3350** both their own internal database and also databases that are controlled
3351** by untrusted external sources.  An example application might be a
3352** web browser that has its own databases for storing history and
3353** separate databases controlled by JavaScript applications downloaded
3354** off the Internet.  The internal databases can be given the
3355** large, default limits.  Databases managed by external sources can
3356** be given much smaller limits designed to prevent a denial of service
3357** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
3358** interface to further control untrusted SQL.  The size of the database
3359** created by an untrusted script can be contained using the
3360** [max_page_count] [PRAGMA].
3362** New run-time limit categories may be added in future releases.
3364SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal);
3367** CAPI3REF: Run-Time Limit Categories
3368** KEYWORDS: {limit category} {*limit categories}
3370** These constants define various performance limits
3371** that can be lowered at run-time using [sqlite3_limit()].
3372** The synopsis of the meanings of the various limits is shown below.
3373** Additional information is available at [limits | Limits in SQLite].
3375** <dl>
3377** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3380** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3383** <dd>The maximum number of columns in a table definition or in the
3384** result set of a [SELECT] or the maximum number of columns in an index
3385** or in an ORDER BY or GROUP BY clause.</dd>)^
3388** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3391** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3394** <dd>The maximum number of instructions in a virtual machine program
3395** used to implement an SQL statement.  This limit is not currently
3396** enforced, though that might be added in some future release of
3397** SQLite.</dd>)^
3400** <dd>The maximum number of arguments on a function.</dd>)^
3403** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3407** <dd>The maximum length of the pattern argument to the [LIKE] or
3408** [GLOB] operators.</dd>)^
3412** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3415** <dd>The maximum depth of recursion for triggers.</dd>)^
3418** <dd>The maximum number of auxiliary worker threads that a single
3419** [prepared statement] may start.</dd>)^
3420** </dl>
3422#define SQLITE_LIMIT_LENGTH                    0
3423#define SQLITE_LIMIT_SQL_LENGTH                1
3424#define SQLITE_LIMIT_COLUMN                    2
3425#define SQLITE_LIMIT_EXPR_DEPTH                3
3426#define SQLITE_LIMIT_COMPOUND_SELECT           4
3427#define SQLITE_LIMIT_VDBE_OP                   5
3428#define SQLITE_LIMIT_FUNCTION_ARG              6
3429#define SQLITE_LIMIT_ATTACHED                  7
3431#define SQLITE_LIMIT_VARIABLE_NUMBER           9
3432#define SQLITE_LIMIT_TRIGGER_DEPTH            10
3433#define SQLITE_LIMIT_WORKER_THREADS           11
3436** CAPI3REF: Compiling An SQL Statement
3437** KEYWORDS: {SQL statement compiler}
3438** METHOD: sqlite3
3439** CONSTRUCTOR: sqlite3_stmt
3441** To execute an SQL query, it must first be compiled into a byte-code
3442** program using one of these routines.
3444** The first argument, "db", is a [database connection] obtained from a
3445** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3446** [sqlite3_open16()].  The database connection must not have been closed.
3448** The second argument, "zSql", is the statement to be compiled, encoded
3449** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
3450** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3451** use UTF-16.
3453** ^If the nByte argument is negative, then zSql is read up to the
3454** first zero terminator. ^If nByte is positive, then it is the
3455** number of bytes read from zSql.  ^If nByte is zero, then no prepared
3456** statement is generated.
3457** If the caller knows that the supplied string is nul-terminated, then
3458** there is a small performance advantage to passing an nByte parameter that
3459** is the number of bytes in the input string <i>including</i>
3460** the nul-terminator.
3462** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3463** past the end of the first SQL statement in zSql.  These routines only
3464** compile the first statement in zSql, so *pzTail is left pointing to
3465** what remains uncompiled.
3467** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3468** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
3469** to NULL.  ^If the input text contains no SQL (if the input is an empty
3470** string or a comment) then *ppStmt is set to NULL.
3471** The calling procedure is responsible for deleting the compiled
3472** SQL statement using [sqlite3_finalize()] after it has finished with it.
3473** ppStmt may not be NULL.
3475** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3476** otherwise an [error code] is returned.
3478** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3479** recommended for all new programs. The two older interfaces are retained
3480** for backwards compatibility, but their use is discouraged.
3481** ^In the "v2" interfaces, the prepared statement
3482** that is returned (the [sqlite3_stmt] object) contains a copy of the
3483** original SQL text. This causes the [sqlite3_step()] interface to
3484** behave differently in three ways:
3486** <ol>
3487** <li>
3488** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3489** always used to do, [sqlite3_step()] will automatically recompile the SQL
3490** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3491** retries will occur before sqlite3_step() gives up and returns an error.
3492** </li>
3494** <li>
3495** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3496** [error codes] or [extended error codes].  ^The legacy behavior was that
3497** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3498** and the application would have to make a second call to [sqlite3_reset()]
3499** in order to find the underlying cause of the problem. With the "v2" prepare
3500** interfaces, the underlying reason for the error is returned immediately.
3501** </li>
3503** <li>
3504** ^If the specific value bound to [parameter | host parameter] in the
3505** WHERE clause might influence the choice of query plan for a statement,
3506** then the statement will be automatically recompiled, as if there had been
3507** a schema change, on the first  [sqlite3_step()] call following any change
3508** to the [sqlite3_bind_text | bindings] of that [parameter].
3509** ^The specific value of WHERE-clause [parameter] might influence the
3510** choice of query plan if the parameter is the left-hand side of a [LIKE]
3511** or [GLOB] operator or if the parameter is compared to an indexed column
3512** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3513** </li>
3514** </ol>
3516SQLITE_API int SQLITE_STDCALL sqlite3_prepare(
3517  sqlite3 *db,            /* Database handle */
3518  const char *zSql,       /* SQL statement, UTF-8 encoded */
3519  int nByte,              /* Maximum length of zSql in bytes. */
3520  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3521  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3523SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2(
3524  sqlite3 *db,            /* Database handle */
3525  const char *zSql,       /* SQL statement, UTF-8 encoded */
3526  int nByte,              /* Maximum length of zSql in bytes. */
3527  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3528  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3530SQLITE_API int SQLITE_STDCALL sqlite3_prepare16(
3531  sqlite3 *db,            /* Database handle */
3532  const void *zSql,       /* SQL statement, UTF-16 encoded */
3533  int nByte,              /* Maximum length of zSql in bytes. */
3534  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3535  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3537SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2(
3538  sqlite3 *db,            /* Database handle */
3539  const void *zSql,       /* SQL statement, UTF-16 encoded */
3540  int nByte,              /* Maximum length of zSql in bytes. */
3541  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3542  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3546** CAPI3REF: Retrieving Statement SQL
3547** METHOD: sqlite3_stmt
3549** ^This interface can be used to retrieve a saved copy of the original
3550** SQL text used to create a [prepared statement] if that statement was
3551** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3553SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt);
3556** CAPI3REF: Determine If An SQL Statement Writes The Database
3557** METHOD: sqlite3_stmt
3559** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3560** and only if the [prepared statement] X makes no direct changes to
3561** the content of the database file.
3563** Note that [application-defined SQL functions] or
3564** [virtual tables] might change the database indirectly as a side effect.
3565** ^(For example, if an application defines a function "eval()" that
3566** calls [sqlite3_exec()], then the following SQL statement would
3567** change the database file through side-effects:
3569** <blockquote><pre>
3570**    SELECT eval('DELETE FROM t1') FROM t2;
3571** </pre></blockquote>
3573** But because the [SELECT] statement does not change the database file
3574** directly, sqlite3_stmt_readonly() would still return true.)^
3576** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3577** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3578** since the statements themselves do not actually modify the database but
3579** rather they control the timing of when other statements modify the
3580** database.  ^The [ATTACH] and [DETACH] statements also cause
3581** sqlite3_stmt_readonly() to return true since, while those statements
3582** change the configuration of a database connection, they do not make
3583** changes to the content of the database files on disk.
3585SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3588** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3589** METHOD: sqlite3_stmt
3591** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3592** [prepared statement] S has been stepped at least once using
3593** [sqlite3_step(S)] but has neither run to completion (returned
3594** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3595** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
3596** interface returns false if S is a NULL pointer.  If S is not a
3597** NULL pointer and is not a pointer to a valid [prepared statement]
3598** object, then the behavior is undefined and probably undesirable.
3600** This interface can be used in combination [sqlite3_next_stmt()]
3601** to locate all prepared statements associated with a database
3602** connection that are in need of being reset.  This can be used,
3603** for example, in diagnostic routines to search for prepared
3604** statements that are holding a transaction open.
3606SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*);
3609** CAPI3REF: Dynamically Typed Value Object
3610** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3612** SQLite uses the sqlite3_value object to represent all values
3613** that can be stored in a database table. SQLite uses dynamic typing
3614** for the values it stores.  ^Values stored in sqlite3_value objects
3615** can be integers, floating point values, strings, BLOBs, or NULL.
3617** An sqlite3_value object may be either "protected" or "unprotected".
3618** Some interfaces require a protected sqlite3_value.  Other interfaces
3619** will accept either a protected or an unprotected sqlite3_value.
3620** Every interface that accepts sqlite3_value arguments specifies
3621** whether or not it requires a protected sqlite3_value.  The
3622** [sqlite3_value_dup()] interface can be used to construct a new
3623** protected sqlite3_value from an unprotected sqlite3_value.
3625** The terms "protected" and "unprotected" refer to whether or not
3626** a mutex is held.  An internal mutex is held for a protected
3627** sqlite3_value object but no mutex is held for an unprotected
3628** sqlite3_value object.  If SQLite is compiled to be single-threaded
3629** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3630** or if SQLite is run in one of reduced mutex modes
3632** then there is no distinction between protected and unprotected
3633** sqlite3_value objects and they can be used interchangeably.  However,
3634** for maximum code portability it is recommended that applications
3635** still make the distinction between protected and unprotected
3636** sqlite3_value objects even when not strictly required.
3638** ^The sqlite3_value objects that are passed as parameters into the
3639** implementation of [application-defined SQL functions] are protected.
3640** ^The sqlite3_value object returned by
3641** [sqlite3_column_value()] is unprotected.
3642** Unprotected sqlite3_value objects may only be used with
3643** [sqlite3_result_value()] and [sqlite3_bind_value()].
3644** The [sqlite3_value_blob | sqlite3_value_type()] family of
3645** interfaces require protected sqlite3_value objects.
3647typedef struct Mem sqlite3_value;
3650** CAPI3REF: SQL Function Context Object
3652** The context in which an SQL function executes is stored in an
3653** sqlite3_context object.  ^A pointer to an sqlite3_context object
3654** is always first parameter to [application-defined SQL functions].
3655** The application-defined SQL function implementation will pass this
3656** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3657** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3658** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3659** and/or [sqlite3_set_auxdata()].
3661typedef struct sqlite3_context sqlite3_context;
3664** CAPI3REF: Binding Values To Prepared Statements
3665** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3666** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3667** METHOD: sqlite3_stmt
3669** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3670** literals may be replaced by a [parameter] that matches one of following
3671** templates:
3673** <ul>
3674** <li>  ?
3675** <li>  ?NNN
3676** <li>  :VVV
3677** <li>  @VVV
3678** <li>  $VVV
3679** </ul>
3681** In the templates above, NNN represents an integer literal,
3682** and VVV represents an alphanumeric identifier.)^  ^The values of these
3683** parameters (also called "host parameter names" or "SQL parameters")
3684** can be set using the sqlite3_bind_*() routines defined here.
3686** ^The first argument to the sqlite3_bind_*() routines is always
3687** a pointer to the [sqlite3_stmt] object returned from
3688** [sqlite3_prepare_v2()] or its variants.
3690** ^The second argument is the index of the SQL parameter to be set.
3691** ^The leftmost SQL parameter has an index of 1.  ^When the same named
3692** SQL parameter is used more than once, second and subsequent
3693** occurrences have the same index as the first occurrence.
3694** ^The index for named parameters can be looked up using the
3695** [sqlite3_bind_parameter_index()] API if desired.  ^The index
3696** for "?NNN" parameters is the value of NNN.
3697** ^The NNN value must be between 1 and the [sqlite3_limit()]
3698** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3700** ^The third argument is the value to bind to the parameter.
3701** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3702** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3703** is ignored and the end result is the same as sqlite3_bind_null().
3705** ^(In those routines that have a fourth argument, its value is the
3706** number of bytes in the parameter.  To be clear: the value is the
3707** number of <u>bytes</u> in the value, not the number of characters.)^
3708** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3709** is negative, then the length of the string is
3710** the number of bytes up to the first zero terminator.
3711** If the fourth parameter to sqlite3_bind_blob() is negative, then
3712** the behavior is undefined.
3713** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3714** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3715** that parameter must be the byte offset
3716** where the NUL terminator would occur assuming the string were NUL
3717** terminated.  If any NUL characters occur at byte offsets less than
3718** the value of the fourth parameter then the resulting string value will
3719** contain embedded NULs.  The result of expressions involving strings
3720** with embedded NULs is undefined.
3722** ^The fifth argument to the BLOB and string binding interfaces
3723** is a destructor used to dispose of the BLOB or
3724** string after SQLite has finished with it.  ^The destructor is called
3725** to dispose of the BLOB or string even if the call to bind API fails.
3726** ^If the fifth argument is
3727** the special value [SQLITE_STATIC], then SQLite assumes that the
3728** information is in static, unmanaged space and does not need to be freed.
3729** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3730** SQLite makes its own private copy of the data immediately, before
3731** the sqlite3_bind_*() routine returns.
3733** ^The sixth argument to sqlite3_bind_text64() must be one of
3735** to specify the encoding of the text in the third parameter.  If
3736** the sixth argument to sqlite3_bind_text64() is not one of the
3737** allowed values shown above, or if the text encoding is different
3738** from the encoding specified by the sixth parameter, then the behavior
3739** is undefined.
3741** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3742** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
3743** (just an integer to hold its size) while it is being processed.
3744** Zeroblobs are intended to serve as placeholders for BLOBs whose
3745** content is later written using
3746** [sqlite3_blob_open | incremental BLOB I/O] routines.
3747** ^A negative value for the zeroblob results in a zero-length BLOB.
3749** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3750** for the [prepared statement] or with a prepared statement for which
3751** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3752** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
3753** routine is passed a [prepared statement] that has been finalized, the
3754** result is undefined and probably harmful.
3756** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3757** ^Unbound parameters are interpreted as NULL.
3759** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3760** [error code] if anything goes wrong.
3761** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
3762** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
3764** ^[SQLITE_RANGE] is returned if the parameter
3765** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
3767** See also: [sqlite3_bind_parameter_count()],
3768** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3770SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3771SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
3772                        void(*)(void*));
3773SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double);
3774SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int);
3775SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3776SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int);
3777SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
3778SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3779SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
3780                         void(*)(void*), unsigned char encoding);
3781SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3782SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3783SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
3786** CAPI3REF: Number Of SQL Parameters
3787** METHOD: sqlite3_stmt
3789** ^This routine can be used to find the number of [SQL parameters]
3790** in a [prepared statement].  SQL parameters are tokens of the
3791** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3792** placeholders for values that are [sqlite3_bind_blob | bound]
3793** to the parameters at a later time.
3795** ^(This routine actually returns the index of the largest (rightmost)
3796** parameter. For all forms except ?NNN, this will correspond to the
3797** number of unique parameters.  If parameters of the ?NNN form are used,
3798** there may be gaps in the list.)^
3800** See also: [sqlite3_bind_blob|sqlite3_bind()],
3801** [sqlite3_bind_parameter_name()], and
3802** [sqlite3_bind_parameter_index()].
3804SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*);
3807** CAPI3REF: Name Of A Host Parameter
3808** METHOD: sqlite3_stmt
3810** ^The sqlite3_bind_parameter_name(P,N) interface returns
3811** the name of the N-th [SQL parameter] in the [prepared statement] P.
3812** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3813** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3814** respectively.
3815** In other words, the initial ":" or "$" or "@" or "?"
3816** is included as part of the name.)^
3817** ^Parameters of the form "?" without a following integer have no name
3818** and are referred to as "nameless" or "anonymous parameters".
3820** ^The first host parameter has an index of 1, not 0.
3822** ^If the value N is out of range or if the N-th parameter is
3823** nameless, then NULL is returned.  ^The returned string is
3824** always in UTF-8 encoding even if the named parameter was
3825** originally specified as UTF-16 in [sqlite3_prepare16()] or
3826** [sqlite3_prepare16_v2()].
3828** See also: [sqlite3_bind_blob|sqlite3_bind()],
3829** [sqlite3_bind_parameter_count()], and
3830** [sqlite3_bind_parameter_index()].
3832SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3835** CAPI3REF: Index Of A Parameter With A Given Name
3836** METHOD: sqlite3_stmt
3838** ^Return the index of an SQL parameter given its name.  ^The
3839** index value returned is suitable for use as the second
3840** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
3841** is returned if no matching parameter is found.  ^The parameter
3842** name must be given in UTF-8 even if the original statement
3843** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3845** See also: [sqlite3_bind_blob|sqlite3_bind()],
3846** [sqlite3_bind_parameter_count()], and
3847** [sqlite3_bind_parameter_name()].
3849SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3852** CAPI3REF: Reset All Bindings On A Prepared Statement
3853** METHOD: sqlite3_stmt
3855** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3856** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3857** ^Use this routine to reset all host parameters to NULL.
3859SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*);
3862** CAPI3REF: Number Of Columns In A Result Set
3863** METHOD: sqlite3_stmt
3865** ^Return the number of columns in the result set returned by the
3866** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3867** statement that does not return data (for example an [UPDATE]).
3869** See also: [sqlite3_data_count()]
3871SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt);
3874** CAPI3REF: Column Names In A Result Set
3875** METHOD: sqlite3_stmt
3877** ^These routines return the name assigned to a particular column
3878** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
3879** interface returns a pointer to a zero-terminated UTF-8 string
3880** and sqlite3_column_name16() returns a pointer to a zero-terminated
3881** UTF-16 string.  ^The first parameter is the [prepared statement]
3882** that implements the [SELECT] statement. ^The second parameter is the
3883** column number.  ^The leftmost column is number 0.
3885** ^The returned string pointer is valid until either the [prepared statement]
3886** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3887** reprepared by the first call to [sqlite3_step()] for a particular run
3888** or until the next call to
3889** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3891** ^If sqlite3_malloc() fails during the processing of either routine
3892** (for example during a conversion from UTF-8 to UTF-16) then a
3893** NULL pointer is returned.
3895** ^The name of a result column is the value of the "AS" clause for
3896** that column, if there is an AS clause.  If there is no AS clause
3897** then the name of the column is unspecified and may change from
3898** one release of SQLite to the next.
3900SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N);
3901SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N);
3904** CAPI3REF: Source Of Data In A Query Result
3905** METHOD: sqlite3_stmt
3907** ^These routines provide a means to determine the database, table, and
3908** table column that is the origin of a particular result column in
3909** [SELECT] statement.
3910** ^The name of the database or table or column can be returned as
3911** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
3912** the database name, the _table_ routines return the table name, and
3913** the origin_ routines return the column name.
3914** ^The returned string is valid until the [prepared statement] is destroyed
3915** using [sqlite3_finalize()] or until the statement is automatically
3916** reprepared by the first call to [sqlite3_step()] for a particular run
3917** or until the same information is requested
3918** again in a different encoding.
3920** ^The names returned are the original un-aliased names of the
3921** database, table, and column.
3923** ^The first argument to these interfaces is a [prepared statement].
3924** ^These functions return information about the Nth result column returned by
3925** the statement, where N is the second function argument.
3926** ^The left-most column is column 0 for these routines.
3928** ^If the Nth column returned by the statement is an expression or
3929** subquery and is not a column value, then all of these functions return
3930** NULL.  ^These routine might also return NULL if a memory allocation error
3931** occurs.  ^Otherwise, they return the name of the attached database, table,
3932** or column that query result column was extracted from.
3934** ^As with all other SQLite APIs, those whose names end with "16" return
3935** UTF-16 encoded strings and the other functions return UTF-8.
3937** ^These APIs are only available if the library was compiled with the
3938** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3940** If two or more threads call one or more of these routines against the same
3941** prepared statement and column at the same time then the results are
3942** undefined.
3944** If two or more threads call one or more
3945** [sqlite3_column_database_name | column metadata interfaces]
3946** for the same [prepared statement] and result column
3947** at the same time then the results are undefined.
3949SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int);
3950SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int);
3951SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int);
3952SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int);
3953SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int);
3954SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int);
3957** CAPI3REF: Declared Datatype Of A Query Result
3958** METHOD: sqlite3_stmt
3960** ^(The first parameter is a [prepared statement].
3961** If this statement is a [SELECT] statement and the Nth column of the
3962** returned result set of that [SELECT] is a table column (not an
3963** expression or subquery) then the declared type of the table
3964** column is returned.)^  ^If the Nth column of the result set is an
3965** expression or subquery, then a NULL pointer is returned.
3966** ^The returned string is always UTF-8 encoded.
3968** ^(For example, given the database schema:
3972** and the following statement to be compiled:
3974** SELECT c1 + 1, c1 FROM t1;
3976** this routine would return the string "VARIANT" for the second result
3977** column (i==1), and a NULL pointer for the first result column (i==0).)^
3979** ^SQLite uses dynamic run-time typing.  ^So just because a column
3980** is declared to contain a particular type does not mean that the
3981** data stored in that column is of the declared type.  SQLite is
3982** strongly typed, but the typing is dynamic not static.  ^Type
3983** is associated with individual values, not with the containers
3984** used to hold those values.
3986SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int);
3987SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int);
3990** CAPI3REF: Evaluate An SQL Statement
3991** METHOD: sqlite3_stmt
3993** After a [prepared statement] has been prepared using either
3994** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3995** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3996** must be called one or more times to evaluate the statement.
3998** The details of the behavior of the sqlite3_step() interface depend
3999** on whether the statement was prepared using the newer "v2" interface
4000** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
4001** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
4002** new "v2" interface is recommended for new applications but the legacy
4003** interface will continue to be supported.
4005** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4007** ^With the "v2" interface, any of the other [result codes] or
4008** [extended result codes] might be returned as well.
4010** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4011** database locks it needs to do its job.  ^If the statement is a [COMMIT]
4012** or occurs outside of an explicit transaction, then you can retry the
4013** statement.  If the statement is not a [COMMIT] and occurs within an
4014** explicit transaction then you should rollback the transaction before
4015** continuing.
4017** ^[SQLITE_DONE] means that the statement has finished executing
4018** successfully.  sqlite3_step() should not be called again on this virtual
4019** machine without first calling [sqlite3_reset()] to reset the virtual
4020** machine back to its initial state.
4022** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4023** is returned each time a new row of data is ready for processing by the
4024** caller. The values may be accessed using the [column access functions].
4025** sqlite3_step() is called again to retrieve the next row of data.
4027** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4028** violation) has occurred.  sqlite3_step() should not be called again on
4029** the VM. More information may be found by calling [sqlite3_errmsg()].
4030** ^With the legacy interface, a more specific error code (for example,
4032** can be obtained by calling [sqlite3_reset()] on the
4033** [prepared statement].  ^In the "v2" interface,
4034** the more specific error code is returned directly by sqlite3_step().
4036** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4037** Perhaps it was called on a [prepared statement] that has
4038** already been [sqlite3_finalize | finalized] or on one that had
4039** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
4040** be the case that the same database connection is being used by two or
4041** more threads at the same moment in time.
4043** For all versions of SQLite up to and including, a call to
4044** [sqlite3_reset()] was required after sqlite3_step() returned anything
4045** other than [SQLITE_ROW] before any subsequent invocation of
4046** sqlite3_step().  Failure to reset the prepared statement using
4047** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4048** sqlite3_step().  But after version, sqlite3_step() began
4049** calling [sqlite3_reset()] automatically in this circumstance rather
4050** than returning [SQLITE_MISUSE].  This is not considered a compatibility
4051** break because any application that ever receives an SQLITE_MISUSE error
4052** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
4053** can be used to restore the legacy behavior.
4055** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4056** API always returns a generic error code, [SQLITE_ERROR], following any
4057** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
4058** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4059** specific [error codes] that better describes the error.
4060** We admit that this is a goofy design.  The problem has been fixed
4061** with the "v2" interface.  If you prepare all of your SQL statements
4062** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
4063** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4064** then the more specific [error codes] are returned directly
4065** by sqlite3_step().  The use of the "v2" interface is recommended.
4067SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*);
4070** CAPI3REF: Number of columns in a result set
4071** METHOD: sqlite3_stmt
4073** ^The sqlite3_data_count(P) interface returns the number of columns in the
4074** current row of the result set of [prepared statement] P.
4075** ^If prepared statement P does not have results ready to return
4076** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4077** interfaces) then sqlite3_data_count(P) returns 0.
4078** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4079** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4080** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
4081** will return non-zero if previous call to [sqlite3_step](P) returned
4082** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4083** where it always returns zero since each step of that multi-step
4084** pragma returns 0 columns of data.
4086** See also: [sqlite3_column_count()]
4088SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt);
4091** CAPI3REF: Fundamental Datatypes
4094** ^(Every value in SQLite has one of five fundamental datatypes:
4096** <ul>
4097** <li> 64-bit signed integer
4098** <li> 64-bit IEEE floating point number
4099** <li> string
4100** <li> BLOB
4101** <li> NULL
4102** </ul>)^
4104** These constants are codes for each of those types.
4106** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4107** for a completely different meaning.  Software that links against both
4108** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4111#define SQLITE_INTEGER  1
4112#define SQLITE_FLOAT    2
4113#define SQLITE_BLOB     4
4114#define SQLITE_NULL     5
4115#ifdef SQLITE_TEXT
4116# undef SQLITE_TEXT
4118# define SQLITE_TEXT     3
4120#define SQLITE3_TEXT     3
4123** CAPI3REF: Result Values From A Query
4124** KEYWORDS: {column access functions}
4125** METHOD: sqlite3_stmt
4127** ^These routines return information about a single column of the current
4128** result row of a query.  ^In every case the first argument is a pointer
4129** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4130** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4131** and the second argument is the index of the column for which information
4132** should be returned. ^The leftmost column of the result set has the index 0.
4133** ^The number of columns in the result can be determined using
4134** [sqlite3_column_count()].
4136** If the SQL statement does not currently point to a valid row, or if the
4137** column index is out of range, the result is undefined.
4138** These routines may only be called when the most recent call to
4139** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4140** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4141** If any of these routines are called after [sqlite3_reset()] or
4142** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4143** something other than [SQLITE_ROW], the results are undefined.
4144** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4145** are called from a different thread while any of these routines
4146** are pending, then the results are undefined.
4148** ^The sqlite3_column_type() routine returns the
4149** [SQLITE_INTEGER | datatype code] for the initial data type
4150** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
4152** returned by sqlite3_column_type() is only meaningful if no type
4153** conversions have occurred as described below.  After a type conversion,
4154** the value returned by sqlite3_column_type() is undefined.  Future
4155** versions of SQLite may change the behavior of sqlite3_column_type()
4156** following a type conversion.
4158** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4159** routine returns the number of bytes in that BLOB or string.
4160** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4161** the string to UTF-8 and then returns the number of bytes.
4162** ^If the result is a numeric value then sqlite3_column_bytes() uses
4163** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4164** the number of bytes in that string.
4165** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4167** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4168** routine returns the number of bytes in that BLOB or string.
4169** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4170** the string to UTF-16 and then returns the number of bytes.
4171** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4172** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4173** the number of bytes in that string.
4174** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4176** ^The values returned by [sqlite3_column_bytes()] and
4177** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4178** of the string.  ^For clarity: the values returned by
4179** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4180** bytes in the string, not the number of characters.
4182** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4183** even empty strings, are always zero-terminated.  ^The return
4184** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4186** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4187** [unprotected sqlite3_value] object.  In a multithreaded environment,
4188** an unprotected sqlite3_value object may only be used safely with
4189** [sqlite3_bind_value()] and [sqlite3_result_value()].
4190** If the [unprotected sqlite3_value] object returned by
4191** [sqlite3_column_value()] is used in any other way, including calls
4192** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4193** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4195** These routines attempt to convert the value where appropriate.  ^For
4196** example, if the internal representation is FLOAT and a text result
4197** is requested, [sqlite3_snprintf()] is used internally to perform the
4198** conversion automatically.  ^(The following table details the conversions
4199** that are applied:
4201** <blockquote>
4202** <table border="1">
4203** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
4205** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
4206** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
4207** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
4208** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
4209** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
4210** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
4211** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
4212** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
4213** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
4214** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
4215** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
4216** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
4217** <tr><td>  TEXT    <td>   BLOB    <td> No change
4218** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
4219** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
4220** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
4221** </table>
4222** </blockquote>)^
4224** Note that when type conversions occur, pointers returned by prior
4225** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4226** sqlite3_column_text16() may be invalidated.
4227** Type conversions and pointer invalidations might occur
4228** in the following cases:
4230** <ul>
4231** <li> The initial content is a BLOB and sqlite3_column_text() or
4232**      sqlite3_column_text16() is called.  A zero-terminator might
4233**      need to be added to the string.</li>
4234** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4235**      sqlite3_column_text16() is called.  The content must be converted
4236**      to UTF-16.</li>
4237** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4238**      sqlite3_column_text() is called.  The content must be converted
4239**      to UTF-8.</li>
4240** </ul>
4242** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4243** not invalidate a prior pointer, though of course the content of the buffer
4244** that the prior pointer references will have been modified.  Other kinds
4245** of conversion are done in place when it is possible, but sometimes they
4246** are not possible and in those cases prior pointers are invalidated.
4248** The safest policy is to invoke these routines
4249** in one of the following ways:
4251** <ul>
4252**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4253**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4254**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4255** </ul>
4257** In other words, you should call sqlite3_column_text(),
4258** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4259** into the desired format, then invoke sqlite3_column_bytes() or
4260** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
4261** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4262** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4263** with calls to sqlite3_column_bytes().
4265** ^The pointers returned are valid until a type conversion occurs as
4266** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4267** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
4268** and BLOBs is freed automatically.  Do <em>not</em> pass the pointers returned
4269** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4270** [sqlite3_free()].
4272** ^(If a memory allocation error occurs during the evaluation of any
4273** of these routines, a default value is returned.  The default value
4274** is either the integer 0, the floating point number 0.0, or a NULL
4275** pointer.  Subsequent calls to [sqlite3_errcode()] will return
4276** [SQLITE_NOMEM].)^
4278SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol);
4279SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4280SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4281SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol);
4282SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol);
4283SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol);
4284SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol);
4285SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol);
4286SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol);
4287SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol);
4290** CAPI3REF: Destroy A Prepared Statement Object
4291** DESTRUCTOR: sqlite3_stmt
4293** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4294** ^If the most recent evaluation of the statement encountered no errors
4295** or if the statement is never been evaluated, then sqlite3_finalize() returns
4296** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
4297** sqlite3_finalize(S) returns the appropriate [error code] or
4298** [extended error code].
4300** ^The sqlite3_finalize(S) routine can be called at any point during
4301** the life cycle of [prepared statement] S:
4302** before statement S is ever evaluated, after
4303** one or more calls to [sqlite3_reset()], or after any call
4304** to [sqlite3_step()] regardless of whether or not the statement has
4305** completed execution.
4307** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4309** The application must finalize every [prepared statement] in order to avoid
4310** resource leaks.  It is a grievous error for the application to try to use
4311** a prepared statement after it has been finalized.  Any use of a prepared
4312** statement after it has been finalized can result in undefined and
4313** undesirable behavior such as segfaults and heap corruption.
4315SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt);
4318** CAPI3REF: Reset A Prepared Statement Object
4319** METHOD: sqlite3_stmt
4321** The sqlite3_reset() function is called to reset a [prepared statement]
4322** object back to its initial state, ready to be re-executed.
4323** ^Any SQL statement variables that had values bound to them using
4324** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4325** Use [sqlite3_clear_bindings()] to reset the bindings.
4327** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4328** back to the beginning of its program.
4330** ^If the most recent call to [sqlite3_step(S)] for the
4331** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4332** or if [sqlite3_step(S)] has never before been called on S,
4333** then [sqlite3_reset(S)] returns [SQLITE_OK].
4335** ^If the most recent call to [sqlite3_step(S)] for the
4336** [prepared statement] S indicated an error, then
4337** [sqlite3_reset(S)] returns an appropriate [error code].
4339** ^The [sqlite3_reset(S)] interface does not change the values
4340** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4342SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt);
4345** CAPI3REF: Create Or Redefine SQL Functions
4346** KEYWORDS: {function creation routines}
4347** KEYWORDS: {application-defined SQL function}
4348** KEYWORDS: {application-defined SQL functions}
4349** METHOD: sqlite3
4351** ^These functions (collectively known as "function creation routines")
4352** are used to add SQL functions or aggregates or to redefine the behavior
4353** of existing SQL functions or aggregates.  The only differences between
4354** these routines are the text encoding expected for
4355** the second parameter (the name of the function being created)
4356** and the presence or absence of a destructor callback for
4357** the application data pointer.
4359** ^The first parameter is the [database connection] to which the SQL
4360** function is to be added.  ^If an application uses more than one database
4361** connection then application-defined SQL functions must be added
4362** to each database connection separately.
4364** ^The second parameter is the name of the SQL function to be created or
4365** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
4366** representation, exclusive of the zero-terminator.  ^Note that the name
4367** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4368** ^Any attempt to create a function with a longer name
4369** will result in [SQLITE_MISUSE] being returned.
4371** ^The third parameter (nArg)
4372** is the number of arguments that the SQL function or
4373** aggregate takes. ^If this parameter is -1, then the SQL function or
4374** aggregate may take any number of arguments between 0 and the limit
4375** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
4376** parameter is less than -1 or greater than 127 then the behavior is
4377** undefined.
4379** ^The fourth parameter, eTextRep, specifies what
4380** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4381** its parameters.  The application should set this parameter to
4382** [SQLITE_UTF16LE] if the function implementation invokes
4383** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4384** implementation invokes [sqlite3_value_text16be()] on an input, or
4385** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4386** otherwise.  ^The same SQL function may be registered multiple times using
4387** different preferred text encodings, with different implementations for
4388** each encoding.
4389** ^When multiple implementations of the same function are available, SQLite
4390** will pick the one that involves the least amount of data conversion.
4392** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4393** to signal that the function will always return the same result given
4394** the same inputs within a single SQL statement.  Most SQL functions are
4395** deterministic.  The built-in [random()] SQL function is an example of a
4396** function that is not deterministic.  The SQLite query planner is able to
4397** perform additional optimizations on deterministic functions, so use
4398** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4400** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
4401** function can gain access to this pointer using [sqlite3_user_data()].)^
4403** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4404** pointers to C-language functions that implement the SQL function or
4405** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4406** callback only; NULL pointers must be passed as the xStep and xFinal
4407** parameters. ^An aggregate SQL function requires an implementation of xStep
4408** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4409** SQL function or aggregate, pass NULL pointers for all three function
4410** callbacks.
4412** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4413** then it is destructor for the application data pointer.
4414** The destructor is invoked when the function is deleted, either by being
4415** overloaded or when the database connection closes.)^
4416** ^The destructor is also invoked if the call to
4417** sqlite3_create_function_v2() fails.
4418** ^When the destructor callback of the tenth parameter is invoked, it
4419** is passed a single argument which is a copy of the application data
4420** pointer which was the fifth parameter to sqlite3_create_function_v2().
4422** ^It is permitted to register multiple implementations of the same
4423** functions with the same name but with either differing numbers of
4424** arguments or differing preferred text encodings.  ^SQLite will use
4425** the implementation that most closely matches the way in which the
4426** SQL function is used.  ^A function implementation with a non-negative
4427** nArg parameter is a better match than a function implementation with
4428** a negative nArg.  ^A function where the preferred text encoding
4429** matches the database encoding is a better
4430** match than a function where the encoding is different.
4431** ^A function where the encoding difference is between UTF16le and UTF16be
4432** is a closer match than a function where the encoding difference is
4433** between UTF8 and UTF16.
4435** ^Built-in functions may be overloaded by new application-defined functions.
4437** ^An application-defined function is permitted to call other
4438** SQLite interfaces.  However, such calls must not
4439** close the database connection nor finalize or reset the prepared
4440** statement in which the function is running.
4442SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
4443  sqlite3 *db,
4444  const char *zFunctionName,
4445  int nArg,
4446  int eTextRep,
4447  void *pApp,
4448  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4449  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4450  void (*xFinal)(sqlite3_context*)
4452SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
4453  sqlite3 *db,
4454  const void *zFunctionName,
4455  int nArg,
4456  int eTextRep,
4457  void *pApp,
4458  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4459  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4460  void (*xFinal)(sqlite3_context*)
4462SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
4463  sqlite3 *db,
4464  const char *zFunctionName,
4465  int nArg,
4466  int eTextRep,
4467  void *pApp,
4468  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4469  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4470  void (*xFinal)(sqlite3_context*),
4471  void(*xDestroy)(void*)
4475** CAPI3REF: Text Encodings
4477** These constant define integer codes that represent the various
4478** text encodings supported by SQLite.
4480#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
4481#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
4482#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
4483#define SQLITE_UTF16          4    /* Use native byte order */
4484#define SQLITE_ANY            5    /* Deprecated */
4485#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
4488** CAPI3REF: Function Flags
4490** These constants may be ORed together with the
4491** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4492** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4493** [sqlite3_create_function_v2()].
4495#define SQLITE_DETERMINISTIC    0x800
4498** CAPI3REF: Deprecated Functions
4501** These functions are [deprecated].  In order to maintain
4502** backwards compatibility with older code, these functions continue
4503** to be supported.  However, new applications should avoid
4504** the use of these functions.  To encourage programmers to avoid
4505** these functions, we will not explain what they do.
4508SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*);
4509SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*);
4510SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4511SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void);
4512SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void);
4513SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4514                      void*,sqlite3_int64);
4518** CAPI3REF: Obtaining SQL Values
4519** METHOD: sqlite3_value
4521** The C-language implementation of SQL functions and aggregates uses
4522** this set of interface routines to access the parameter values on
4523** the function or aggregate.
4525** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4526** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4527** define callbacks that implement the SQL functions and aggregates.
4528** The 3rd parameter to these callbacks is an array of pointers to
4529** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
4530** each parameter to the SQL function.  These routines are used to
4531** extract values from the [sqlite3_value] objects.
4533** These routines work only with [protected sqlite3_value] objects.
4534** Any attempt to use these routines on an [unprotected sqlite3_value]
4535** object results in undefined behavior.
4537** ^These routines work just like the corresponding [column access functions]
4538** except that these routines take a single [protected sqlite3_value] object
4539** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4541** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4542** in the native byte-order of the host machine.  ^The
4543** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4544** extract UTF-16 strings as big-endian and little-endian respectively.
4546** ^(The sqlite3_value_numeric_type() interface attempts to apply
4547** numeric affinity to the value.  This means that an attempt is
4548** made to convert the value to an integer or floating point.  If
4549** such a conversion is possible without loss of information (in other
4550** words, if the value is a string that looks like a number)
4551** then the conversion is performed.  Otherwise no conversion occurs.
4552** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4554** Please pay particular attention to the fact that the pointer returned
4555** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4556** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4557** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4558** or [sqlite3_value_text16()].
4560** These routines must be called from the same thread as
4561** the SQL function that supplied the [sqlite3_value*] parameters.
4563SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*);
4564SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*);
4565SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*);
4566SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*);
4567SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*);
4568SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*);
4569SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*);
4570SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*);
4571SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*);
4572SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*);
4573SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*);
4574SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*);
4577** CAPI3REF: Finding The Subtype Of SQL Values
4578** METHOD: sqlite3_value
4580** The sqlite3_value_subtype(V) function returns the subtype for
4581** an [application-defined SQL function] argument V.  The subtype
4582** information can be used to pass a limited amount of context from
4583** one SQL function to another.  Use the [sqlite3_result_subtype()]
4584** routine to set the subtype for the return value of an SQL function.
4586** SQLite makes no use of subtype itself.  It merely passes the subtype
4587** from the result of one [application-defined SQL function] into the
4588** input of another.
4590SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*);
4593** CAPI3REF: Copy And Free SQL Values
4594** METHOD: sqlite3_value
4596** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
4597** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
4598** is a [protected sqlite3_value] object even if the input is not.
4599** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
4600** memory allocation fails.
4602** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
4603** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
4604** then sqlite3_value_free(V) is a harmless no-op.
4606SQLITE_API SQLITE_EXPERIMENTAL sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*);
4607SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*);
4610** CAPI3REF: Obtain Aggregate Function Context
4611** METHOD: sqlite3_context
4613** Implementations of aggregate SQL functions use this
4614** routine to allocate memory for storing their state.
4616** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4617** for a particular aggregate function, SQLite
4618** allocates N of memory, zeroes out that memory, and returns a pointer
4619** to the new memory. ^On second and subsequent calls to
4620** sqlite3_aggregate_context() for the same aggregate function instance,
4621** the same buffer is returned.  Sqlite3_aggregate_context() is normally
4622** called once for each invocation of the xStep callback and then one
4623** last time when the xFinal callback is invoked.  ^(When no rows match
4624** an aggregate query, the xStep() callback of the aggregate function
4625** implementation is never called and xFinal() is called exactly once.
4626** In those cases, sqlite3_aggregate_context() might be called for the
4627** first time from within xFinal().)^
4629** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4630** when first called if N is less than or equal to zero or if a memory
4631** allocate error occurs.
4633** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4634** determined by the N parameter on first successful call.  Changing the
4635** value of N in subsequent call to sqlite3_aggregate_context() within
4636** the same aggregate function instance will not resize the memory
4637** allocation.)^  Within the xFinal callback, it is customary to set
4638** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4639** pointless memory allocations occur.
4641** ^SQLite automatically frees the memory allocated by
4642** sqlite3_aggregate_context() when the aggregate query concludes.
4644** The first parameter must be a copy of the
4645** [sqlite3_context | SQL function context] that is the first parameter
4646** to the xStep or xFinal callback routine that implements the aggregate
4647** function.
4649** This routine must be called from the same thread in which
4650** the aggregate SQL function is running.
4652SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4655** CAPI3REF: User Data For Functions
4656** METHOD: sqlite3_context
4658** ^The sqlite3_user_data() interface returns a copy of
4659** the pointer that was the pUserData parameter (the 5th parameter)
4660** of the [sqlite3_create_function()]
4661** and [sqlite3_create_function16()] routines that originally
4662** registered the application defined function.
4664** This routine must be called from the same thread in which
4665** the application-defined function is running.
4667SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*);
4670** CAPI3REF: Database Connection For Functions
4671** METHOD: sqlite3_context
4673** ^The sqlite3_context_db_handle() interface returns a copy of
4674** the pointer to the [database connection] (the 1st parameter)
4675** of the [sqlite3_create_function()]
4676** and [sqlite3_create_function16()] routines that originally
4677** registered the application defined function.
4679SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*);
4682** CAPI3REF: Function Auxiliary Data
4683** METHOD: sqlite3_context
4685** These functions may be used by (non-aggregate) SQL functions to
4686** associate metadata with argument values. If the same value is passed to
4687** multiple invocations of the same SQL function during query execution, under
4688** some circumstances the associated metadata may be preserved.  An example
4689** of where this might be useful is in a regular-expression matching
4690** function. The compiled version of the regular expression can be stored as
4691** metadata associated with the pattern string.
4692** Then as long as the pattern string remains the same,
4693** the compiled regular expression can be reused on multiple
4694** invocations of the same function.
4696** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4697** associated by the sqlite3_set_auxdata() function with the Nth argument
4698** value to the application-defined function. ^If there is no metadata
4699** associated with the function argument, this sqlite3_get_auxdata() interface
4700** returns a NULL pointer.
4702** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4703** argument of the application-defined function.  ^Subsequent
4704** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4705** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4706** NULL if the metadata has been discarded.
4707** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4708** SQLite will invoke the destructor function X with parameter P exactly
4709** once, when the metadata is discarded.
4710** SQLite is free to discard the metadata at any time, including: <ul>
4711** <li> when the corresponding function parameter changes, or
4712** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4713**      SQL statement, or
4714** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
4715** <li> during the original sqlite3_set_auxdata() call when a memory
4716**      allocation error occurs. </ul>)^
4718** Note the last bullet in particular.  The destructor X in
4719** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4720** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
4721** should be called near the end of the function implementation and the
4722** function implementation should not make any use of P after
4723** sqlite3_set_auxdata() has been called.
4725** ^(In practice, metadata is preserved between function calls for
4726** function parameters that are compile-time constants, including literal
4727** values and [parameters] and expressions composed from the same.)^
4729** These routines must be called from the same thread in which
4730** the SQL function is running.
4732SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N);
4733SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4737** CAPI3REF: Constants Defining Special Destructor Behavior
4739** These are special values for the destructor that is passed in as the
4740** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
4741** argument is SQLITE_STATIC, it means that the content pointer is constant
4742** and will never change.  It does not need to be destroyed.  ^The
4743** SQLITE_TRANSIENT value means that the content will likely change in
4744** the near future and that SQLite should make its own private copy of
4745** the content before returning.
4747** The typedef is necessary to work around problems in certain
4748** C++ compilers.
4750typedef void (*sqlite3_destructor_type)(void*);
4751#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
4752#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
4755** CAPI3REF: Setting The Result Of An SQL Function
4756** METHOD: sqlite3_context
4758** These routines are used by the xFunc or xFinal callbacks that
4759** implement SQL functions and aggregates.  See
4760** [sqlite3_create_function()] and [sqlite3_create_function16()]
4761** for additional information.
4763** These functions work very much like the [parameter binding] family of
4764** functions used to bind values to host parameters in prepared statements.
4765** Refer to the [SQL parameter] documentation for additional information.
4767** ^The sqlite3_result_blob() interface sets the result from
4768** an application-defined function to be the BLOB whose content is pointed
4769** to by the second parameter and which is N bytes long where N is the
4770** third parameter.
4772** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
4773** interfaces set the result of the application-defined function to be
4774** a BLOB containing all zero bytes and N bytes in size.
4776** ^The sqlite3_result_double() interface sets the result from
4777** an application-defined function to be a floating point value specified
4778** by its 2nd argument.
4780** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4781** cause the implemented SQL function to throw an exception.
4782** ^SQLite uses the string pointed to by the
4783** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4784** as the text of an error message.  ^SQLite interprets the error
4785** message string from sqlite3_result_error() as UTF-8. ^SQLite
4786** interprets the string from sqlite3_result_error16() as UTF-16 in native
4787** byte order.  ^If the third parameter to sqlite3_result_error()
4788** or sqlite3_result_error16() is negative then SQLite takes as the error
4789** message all text up through the first zero character.
4790** ^If the third parameter to sqlite3_result_error() or
4791** sqlite3_result_error16() is non-negative then SQLite takes that many
4792** bytes (not characters) from the 2nd parameter as the error message.
4793** ^The sqlite3_result_error() and sqlite3_result_error16()
4794** routines make a private copy of the error message text before
4795** they return.  Hence, the calling function can deallocate or
4796** modify the text after they return without harm.
4797** ^The sqlite3_result_error_code() function changes the error code
4798** returned by SQLite as a result of an error in a function.  ^By default,
4799** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
4800** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4802** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4803** error indicating that a string or BLOB is too long to represent.
4805** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4806** error indicating that a memory allocation failed.
4808** ^The sqlite3_result_int() interface sets the return value
4809** of the application-defined function to be the 32-bit signed integer
4810** value given in the 2nd argument.
4811** ^The sqlite3_result_int64() interface sets the return value
4812** of the application-defined function to be the 64-bit signed integer
4813** value given in the 2nd argument.
4815** ^The sqlite3_result_null() interface sets the return value
4816** of the application-defined function to be NULL.
4818** ^The sqlite3_result_text(), sqlite3_result_text16(),
4819** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4820** set the return value of the application-defined function to be
4821** a text string which is represented as UTF-8, UTF-16 native byte order,
4822** UTF-16 little endian, or UTF-16 big endian, respectively.
4823** ^The sqlite3_result_text64() interface sets the return value of an
4824** application-defined function to be a text string in an encoding
4825** specified by the fifth (and last) parameter, which must be one
4827** ^SQLite takes the text result from the application from
4828** the 2nd parameter of the sqlite3_result_text* interfaces.
4829** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4830** is negative, then SQLite takes result text from the 2nd parameter
4831** through the first zero character.
4832** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4833** is non-negative, then as many bytes (not characters) of the text
4834** pointed to by the 2nd parameter are taken as the application-defined
4835** function result.  If the 3rd parameter is non-negative, then it
4836** must be the byte offset into the string where the NUL terminator would
4837** appear if the string where NUL terminated.  If any NUL characters occur
4838** in the string at a byte offset that is less than the value of the 3rd
4839** parameter, then the resulting string will contain embedded NULs and the
4840** result of expressions operating on strings with embedded NULs is undefined.
4841** ^If the 4th parameter to the sqlite3_result_text* interfaces
4842** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4843** function as the destructor on the text or BLOB result when it has
4844** finished using that result.
4845** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4846** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4847** assumes that the text or BLOB result is in constant space and does not
4848** copy the content of the parameter nor call a destructor on the content
4849** when it has finished using that result.
4850** ^If the 4th parameter to the sqlite3_result_text* interfaces
4851** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4852** then SQLite makes a copy of the result into space obtained from
4853** from [sqlite3_malloc()] before it returns.
4855** ^The sqlite3_result_value() interface sets the result of
4856** the application-defined function to be a copy of the
4857** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
4858** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4859** so that the [sqlite3_value] specified in the parameter may change or
4860** be deallocated after sqlite3_result_value() returns without harm.
4861** ^A [protected sqlite3_value] object may always be used where an
4862** [unprotected sqlite3_value] object is required, so either
4863** kind of [sqlite3_value] object can be used with this interface.
4865** If these routines are called from within the different thread
4866** than the one containing the application-defined function that received
4867** the [sqlite3_context] pointer, the results are undefined.
4869SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4870SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*,
4871                           sqlite3_uint64,void(*)(void*));
4872SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double);
4873SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int);
4874SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int);
4875SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*);
4876SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*);
4877SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int);
4878SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int);
4879SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4880SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*);
4881SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4882SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
4883                           void(*)(void*), unsigned char encoding);
4884SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4885SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4886SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4887SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4888SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n);
4889SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
4893** CAPI3REF: Setting The Subtype Of An SQL Function
4894** METHOD: sqlite3_context
4896** The sqlite3_result_subtype(C,T) function causes the subtype of
4897** the result from the [application-defined SQL function] with
4898** [sqlite3_context] C to be the value T.  Only the lower 8 bits
4899** of the subtype T are preserved in current versions of SQLite;
4900** higher order bits are discarded.
4901** The number of subtype bytes preserved by SQLite might increase
4902** in future releases of SQLite.
4904SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int);
4907** CAPI3REF: Define New Collating Sequences
4908** METHOD: sqlite3
4910** ^These functions add, remove, or modify a [collation] associated
4911** with the [database connection] specified as the first argument.
4913** ^The name of the collation is a UTF-8 string
4914** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4915** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4916** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4917** considered to be the same name.
4919** ^(The third argument (eTextRep) must be one of the constants:
4920** <ul>
4921** <li> [SQLITE_UTF8],
4922** <li> [SQLITE_UTF16LE],
4923** <li> [SQLITE_UTF16BE],
4924** <li> [SQLITE_UTF16], or
4925** <li> [SQLITE_UTF16_ALIGNED].
4926** </ul>)^
4927** ^The eTextRep argument determines the encoding of strings passed
4928** to the collating function callback, xCallback.
4929** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4930** force strings to be UTF16 with native byte order.
4931** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4932** on an even byte address.
4934** ^The fourth argument, pArg, is an application data pointer that is passed
4935** through as the first argument to the collating function callback.
4937** ^The fifth argument, xCallback, is a pointer to the collating function.
4938** ^Multiple collating functions can be registered using the same name but
4939** with different eTextRep parameters and SQLite will use whichever
4940** function requires the least amount of data transformation.
4941** ^If the xCallback argument is NULL then the collating function is
4942** deleted.  ^When all collating functions having the same name are deleted,
4943** that collation is no longer usable.
4945** ^The collating function callback is invoked with a copy of the pArg
4946** application data pointer and with two strings in the encoding specified
4947** by the eTextRep argument.  The collating function must return an
4948** integer that is negative, zero, or positive
4949** if the first string is less than, equal to, or greater than the second,
4950** respectively.  A collating function must always return the same answer
4951** given the same inputs.  If two or more collating functions are registered
4952** to the same collation name (using different eTextRep values) then all
4953** must give an equivalent answer when invoked with equivalent strings.
4954** The collating function must obey the following properties for all
4955** strings A, B, and C:
4957** <ol>
4958** <li> If A==B then B==A.
4959** <li> If A==B and B==C then A==C.
4960** <li> If A&lt;B THEN B&gt;A.
4961** <li> If A&lt;B and B&lt;C then A&lt;C.
4962** </ol>
4964** If a collating function fails any of the above constraints and that
4965** collating function is  registered and used, then the behavior of SQLite
4966** is undefined.
4968** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4969** with the addition that the xDestroy callback is invoked on pArg when
4970** the collating function is deleted.
4971** ^Collating functions are deleted when they are overridden by later
4972** calls to the collation creation functions or when the
4973** [database connection] is closed using [sqlite3_close()].
4975** ^The xDestroy callback is <u>not</u> called if the
4976** sqlite3_create_collation_v2() function fails.  Applications that invoke
4977** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4978** check the return code and dispose of the application data pointer
4979** themselves rather than expecting SQLite to deal with it for them.
4980** This is different from every other SQLite interface.  The inconsistency
4981** is unfortunate but cannot be changed without breaking backwards
4982** compatibility.
4984** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4986SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
4987  sqlite3*,
4988  const char *zName,
4989  int eTextRep,
4990  void *pArg,
4991  int(*xCompare)(void*,int,const void*,int,const void*)
4993SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
4994  sqlite3*,
4995  const char *zName,
4996  int eTextRep,
4997  void *pArg,
4998  int(*xCompare)(void*,int,const void*,int,const void*),
4999  void(*xDestroy)(void*)
5001SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
5002  sqlite3*,
5003  const void *zName,
5004  int eTextRep,
5005  void *pArg,
5006  int(*xCompare)(void*,int,const void*,int,const void*)
5010** CAPI3REF: Collation Needed Callbacks
5011** METHOD: sqlite3
5013** ^To avoid having to register all collation sequences before a database
5014** can be used, a single callback function may be registered with the
5015** [database connection] to be invoked whenever an undefined collation
5016** sequence is required.
5018** ^If the function is registered using the sqlite3_collation_needed() API,
5019** then it is passed the names of undefined collation sequences as strings
5020** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5021** the names are passed as UTF-16 in machine native byte order.
5022** ^A call to either function replaces the existing collation-needed callback.
5024** ^(When the callback is invoked, the first argument passed is a copy
5025** of the second argument to sqlite3_collation_needed() or
5026** sqlite3_collation_needed16().  The second argument is the database
5027** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5028** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5029** sequence function required.  The fourth parameter is the name of the
5030** required collation sequence.)^
5032** The callback function should register the desired collation using
5033** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5034** [sqlite3_create_collation_v2()].
5036SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
5037  sqlite3*,
5038  void*,
5039  void(*)(void*,sqlite3*,int eTextRep,const char*)
5041SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
5042  sqlite3*,
5043  void*,
5044  void(*)(void*,sqlite3*,int eTextRep,const void*)
5049** Specify the key for an encrypted database.  This routine should be
5050** called right after sqlite3_open().
5052** The code to implement this API is not available in the public release
5053** of SQLite.
5055SQLITE_API int SQLITE_STDCALL sqlite3_key(
5056  sqlite3 *db,                   /* Database to be rekeyed */
5057  const void *pKey, int nKey     /* The key */
5059SQLITE_API int SQLITE_STDCALL sqlite3_key_v2(
5060  sqlite3 *db,                   /* Database to be rekeyed */
5061  const char *zDbName,           /* Name of the database */
5062  const void *pKey, int nKey     /* The key */
5066** Change the key on an open database.  If the current database is not
5067** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
5068** database is decrypted.
5070** The code to implement this API is not available in the public release
5071** of SQLite.
5073SQLITE_API int SQLITE_STDCALL sqlite3_rekey(
5074  sqlite3 *db,                   /* Database to be rekeyed */
5075  const void *pKey, int nKey     /* The new key */
5077SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2(
5078  sqlite3 *db,                   /* Database to be rekeyed */
5079  const char *zDbName,           /* Name of the database */
5080  const void *pKey, int nKey     /* The new key */
5084** Specify the activation key for a SEE database.  Unless
5085** activated, none of the SEE routines will work.
5087SQLITE_API void SQLITE_STDCALL sqlite3_activate_see(
5088  const char *zPassPhrase        /* Activation phrase */
5094** Specify the activation key for a CEROD database.  Unless
5095** activated, none of the CEROD routines will work.
5097SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod(
5098  const char *zPassPhrase        /* Activation phrase */
5103** CAPI3REF: Suspend Execution For A Short Time
5105** The sqlite3_sleep() function causes the current thread to suspend execution
5106** for at least a number of milliseconds specified in its parameter.
5108** If the operating system does not support sleep requests with
5109** millisecond time resolution, then the time will be rounded up to
5110** the nearest second. The number of milliseconds of sleep actually
5111** requested from the operating system is returned.
5113** ^SQLite implements this interface by calling the xSleep()
5114** method of the default [sqlite3_vfs] object.  If the xSleep() method
5115** of the default VFS is not implemented correctly, or not implemented at
5116** all, then the behavior of sqlite3_sleep() may deviate from the description
5117** in the previous paragraphs.
5119SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int);
5122** CAPI3REF: Name Of The Folder Holding Temporary Files
5124** ^(If this global variable is made to point to a string which is
5125** the name of a folder (a.k.a. directory), then all temporary files
5126** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5127** will be placed in that directory.)^  ^If this variable
5128** is a NULL pointer, then SQLite performs a search for an appropriate
5129** temporary file directory.
5131** Applications are strongly discouraged from using this global variable.
5132** It is required to set a temporary folder on Windows Runtime (WinRT).
5133** But for all other platforms, it is highly recommended that applications
5134** neither read nor write this variable.  This global variable is a relic
5135** that exists for backwards compatibility of legacy applications and should
5136** be avoided in new projects.
5138** It is not safe to read or modify this variable in more than one
5139** thread at a time.  It is not safe to read or modify this variable
5140** if a [database connection] is being used at the same time in a separate
5141** thread.
5142** It is intended that this variable be set once
5143** as part of process initialization and before any SQLite interface
5144** routines have been called and that this variable remain unchanged
5145** thereafter.
5147** ^The [temp_store_directory pragma] may modify this variable and cause
5148** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
5149** the [temp_store_directory pragma] always assumes that any string
5150** that this variable points to is held in memory obtained from
5151** [sqlite3_malloc] and the pragma may attempt to free that memory
5152** using [sqlite3_free].
5153** Hence, if this variable is modified directly, either it should be
5154** made NULL or made to point to memory obtained from [sqlite3_malloc]
5155** or else the use of the [temp_store_directory pragma] should be avoided.
5156** Except when requested by the [temp_store_directory pragma], SQLite
5157** does not free the memory that sqlite3_temp_directory points to.  If
5158** the application wants that memory to be freed, it must do
5159** so itself, taking care to only do so after all [database connection]
5160** objects have been destroyed.
5162** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
5163** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
5164** features that require the use of temporary files may fail.  Here is an
5165** example of how to do this using C++ with the Windows Runtime:
5167** <blockquote><pre>
5168** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5169** &nbsp;     TemporaryFolder->Path->Data();
5170** char zPathBuf&#91;MAX_PATH + 1&#93;;
5171** memset(zPathBuf, 0, sizeof(zPathBuf));
5172** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5173** &nbsp;     NULL, NULL);
5174** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5175** </pre></blockquote>
5177SQLITE_API char *sqlite3_temp_directory;
5180** CAPI3REF: Name Of The Folder Holding Database Files
5182** ^(If this global variable is made to point to a string which is
5183** the name of a folder (a.k.a. directory), then all database files
5184** specified with a relative pathname and created or accessed by
5185** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5186** to be relative to that directory.)^ ^If this variable is a NULL
5187** pointer, then SQLite assumes that all database files specified
5188** with a relative pathname are relative to the current directory
5189** for the process.  Only the windows VFS makes use of this global
5190** variable; it is ignored by the unix VFS.
5192** Changing the value of this variable while a database connection is
5193** open can result in a corrupt database.
5195** It is not safe to read or modify this variable in more than one
5196** thread at a time.  It is not safe to read or modify this variable
5197** if a [database connection] is being used at the same time in a separate
5198** thread.
5199** It is intended that this variable be set once
5200** as part of process initialization and before any SQLite interface
5201** routines have been called and that this variable remain unchanged
5202** thereafter.
5204** ^The [data_store_directory pragma] may modify this variable and cause
5205** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
5206** the [data_store_directory pragma] always assumes that any string
5207** that this variable points to is held in memory obtained from
5208** [sqlite3_malloc] and the pragma may attempt to free that memory
5209** using [sqlite3_free].
5210** Hence, if this variable is modified directly, either it should be
5211** made NULL or made to point to memory obtained from [sqlite3_malloc]
5212** or else the use of the [data_store_directory pragma] should be avoided.
5214SQLITE_API char *sqlite3_data_directory;
5217** CAPI3REF: Test For Auto-Commit Mode
5218** KEYWORDS: {autocommit mode}
5219** METHOD: sqlite3
5221** ^The sqlite3_get_autocommit() interface returns non-zero or
5222** zero if the given database connection is or is not in autocommit mode,
5223** respectively.  ^Autocommit mode is on by default.
5224** ^Autocommit mode is disabled by a [BEGIN] statement.
5225** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5227** If certain kinds of errors occur on a statement within a multi-statement
5228** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5230** transaction might be rolled back automatically.  The only way to
5231** find out whether SQLite automatically rolled back the transaction after
5232** an error is to use this function.
5234** If another thread changes the autocommit status of the database
5235** connection while this routine is running, then the return value
5236** is undefined.
5238SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*);
5241** CAPI3REF: Find The Database Handle Of A Prepared Statement
5242** METHOD: sqlite3_stmt
5244** ^The sqlite3_db_handle interface returns the [database connection] handle
5245** to which a [prepared statement] belongs.  ^The [database connection]
5246** returned by sqlite3_db_handle is the same [database connection]
5247** that was the first argument
5248** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5249** create the statement in the first place.
5251SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*);
5254** CAPI3REF: Return The Filename For A Database Connection
5255** METHOD: sqlite3
5257** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5258** associated with database N of connection D.  ^The main database file
5259** has the name "main".  If there is no attached database N on the database
5260** connection D, or if database N is a temporary or in-memory database, then
5261** a NULL pointer is returned.
5263** ^The filename returned by this function is the output of the
5264** xFullPathname method of the [VFS].  ^In other words, the filename
5265** will be an absolute pathname, even if the filename used
5266** to open the database originally was a URI or relative pathname.
5268SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5271** CAPI3REF: Determine if a database is read-only
5272** METHOD: sqlite3
5274** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5275** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5276** the name of a database on connection D.
5278SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5281** CAPI3REF: Find the next prepared statement
5282** METHOD: sqlite3
5284** ^This interface returns a pointer to the next [prepared statement] after
5285** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
5286** then this interface returns a pointer to the first prepared statement
5287** associated with the database connection pDb.  ^If no prepared statement
5288** satisfies the conditions of this routine, it returns NULL.
5290** The [database connection] pointer D in a call to
5291** [sqlite3_next_stmt(D,S)] must refer to an open database
5292** connection and in particular must not be a NULL pointer.
5294SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5297** CAPI3REF: Commit And Rollback Notification Callbacks
5298** METHOD: sqlite3
5300** ^The sqlite3_commit_hook() interface registers a callback
5301** function to be invoked whenever a transaction is [COMMIT | committed].
5302** ^Any callback set by a previous call to sqlite3_commit_hook()
5303** for the same database connection is overridden.
5304** ^The sqlite3_rollback_hook() interface registers a callback
5305** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5306** ^Any callback set by a previous call to sqlite3_rollback_hook()
5307** for the same database connection is overridden.
5308** ^The pArg argument is passed through to the callback.
5309** ^If the callback on a commit hook function returns non-zero,
5310** then the commit is converted into a rollback.
5312** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5313** return the P argument from the previous call of the same function
5314** on the same [database connection] D, or NULL for
5315** the first call for each function on D.
5317** The commit and rollback hook callbacks are not reentrant.
5318** The callback implementation must not do anything that will modify
5319** the database connection that invoked the callback.  Any actions
5320** to modify the database connection must be deferred until after the
5321** completion of the [sqlite3_step()] call that triggered the commit
5322** or rollback hook in the first place.
5323** Note that running any other SQL statements, including SELECT statements,
5324** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5325** the database connections for the meaning of "modify" in this paragraph.
5327** ^Registering a NULL function disables the callback.
5329** ^When the commit hook callback routine returns zero, the [COMMIT]
5330** operation is allowed to continue normally.  ^If the commit hook
5331** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5332** ^The rollback hook is invoked on a rollback that results from a commit
5333** hook returning non-zero, just as it would be with any other rollback.
5335** ^For the purposes of this API, a transaction is said to have been
5336** rolled back if an explicit "ROLLBACK" statement is executed, or
5337** an error or constraint causes an implicit rollback to occur.
5338** ^The rollback callback is not invoked if a transaction is
5339** automatically rolled back because the database connection is closed.
5341** See also the [sqlite3_update_hook()] interface.
5343SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5344SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5347** CAPI3REF: Data Change Notification Callbacks
5348** METHOD: sqlite3
5350** ^The sqlite3_update_hook() interface registers a callback function
5351** with the [database connection] identified by the first argument
5352** to be invoked whenever a row is updated, inserted or deleted in
5353** a rowid table.
5354** ^Any callback set by a previous call to this function
5355** for the same database connection is overridden.
5357** ^The second argument is a pointer to the function to invoke when a
5358** row is updated, inserted or deleted in a rowid table.
5359** ^The first argument to the callback is a copy of the third argument
5360** to sqlite3_update_hook().
5361** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5362** or [SQLITE_UPDATE], depending on the operation that caused the callback
5363** to be invoked.
5364** ^The third and fourth arguments to the callback contain pointers to the
5365** database and table name containing the affected row.
5366** ^The final callback parameter is the [rowid] of the row.
5367** ^In the case of an update, this is the [rowid] after the update takes place.
5369** ^(The update hook is not invoked when internal system tables are
5370** modified (i.e. sqlite_master and sqlite_sequence).)^
5371** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5373** ^In the current implementation, the update hook
5374** is not invoked when duplication rows are deleted because of an
5375** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
5376** invoked when rows are deleted using the [truncate optimization].
5377** The exceptions defined in this paragraph might change in a future
5378** release of SQLite.
5380** The update hook implementation must not do anything that will modify
5381** the database connection that invoked the update hook.  Any actions
5382** to modify the database connection must be deferred until after the
5383** completion of the [sqlite3_step()] call that triggered the update hook.
5384** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5385** database connections for the meaning of "modify" in this paragraph.
5387** ^The sqlite3_update_hook(D,C,P) function
5388** returns the P argument from the previous call
5389** on the same [database connection] D, or NULL for
5390** the first call on D.
5392** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
5393** interfaces.
5395SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
5396  sqlite3*,
5397  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5398  void*
5402** CAPI3REF: Enable Or Disable Shared Pager Cache
5404** ^(This routine enables or disables the sharing of the database cache
5405** and schema data structures between [database connection | connections]
5406** to the same database. Sharing is enabled if the argument is true
5407** and disabled if the argument is false.)^
5409** ^Cache sharing is enabled and disabled for an entire process.
5410** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
5411** sharing was enabled or disabled for each thread separately.
5413** ^(The cache sharing mode set by this interface effects all subsequent
5414** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5415** Existing database connections continue use the sharing mode
5416** that was in effect at the time they were opened.)^
5418** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5419** successfully.  An [error code] is returned otherwise.)^
5421** ^Shared cache is disabled by default. But this might change in
5422** future releases of SQLite.  Applications that care about shared
5423** cache setting should set it explicitly.
5425** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5426** and will always return SQLITE_MISUSE. On those systems,
5427** shared cache mode should be enabled per-database connection via
5428** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5430** This interface is threadsafe on processors where writing a
5431** 32-bit integer is atomic.
5433** See Also:  [SQLite Shared-Cache Mode]
5435SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int);
5438** CAPI3REF: Attempt To Free Heap Memory
5440** ^The sqlite3_release_memory() interface attempts to free N bytes
5441** of heap memory by deallocating non-essential memory allocations
5442** held by the database library.   Memory used to cache database
5443** pages to improve performance is an example of non-essential memory.
5444** ^sqlite3_release_memory() returns the number of bytes actually freed,
5445** which might be more or less than the amount requested.
5446** ^The sqlite3_release_memory() routine is a no-op returning zero
5447** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5449** See also: [sqlite3_db_release_memory()]
5451SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int);
5454** CAPI3REF: Free Memory Used By A Database Connection
5455** METHOD: sqlite3
5457** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5458** memory as possible from database connection D. Unlike the
5459** [sqlite3_release_memory()] interface, this interface is in effect even
5460** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5461** omitted.
5463** See also: [sqlite3_release_memory()]
5465SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*);
5468** CAPI3REF: Impose A Limit On Heap Size
5470** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5471** soft limit on the amount of heap memory that may be allocated by SQLite.
5472** ^SQLite strives to keep heap memory utilization below the soft heap
5473** limit by reducing the number of pages held in the page cache
5474** as heap memory usages approaches the limit.
5475** ^The soft heap limit is "soft" because even though SQLite strives to stay
5476** below the limit, it will exceed the limit rather than generate
5477** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
5478** is advisory only.
5480** ^The return value from sqlite3_soft_heap_limit64() is the size of
5481** the soft heap limit prior to the call, or negative in the case of an
5482** error.  ^If the argument N is negative
5483** then no change is made to the soft heap limit.  Hence, the current
5484** size of the soft heap limit can be determined by invoking
5485** sqlite3_soft_heap_limit64() with a negative argument.
5487** ^If the argument N is zero then the soft heap limit is disabled.
5489** ^(The soft heap limit is not enforced in the current implementation
5490** if one or more of following conditions are true:
5492** <ul>
5493** <li> The soft heap limit is set to zero.
5494** <li> Memory accounting is disabled using a combination of the
5495**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5496**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5497** <li> An alternative page cache implementation is specified using
5498**      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5499** <li> The page cache allocates from its own memory pool supplied
5500**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5501**      from the heap.
5502** </ul>)^
5504** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5505** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5506** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5507** the soft heap limit is enforced on every memory allocation.  Without
5508** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5509** when memory is allocated by the page cache.  Testing suggests that because
5510** the page cache is the predominate memory user in SQLite, most
5511** applications will achieve adequate soft heap limit enforcement without
5514** The circumstances under which SQLite will enforce the soft heap limit may
5515** changes in future releases of SQLite.
5517SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N);
5520** CAPI3REF: Deprecated Soft Heap Limit Interface
5523** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5524** interface.  This routine is provided for historical compatibility
5525** only.  All new applications should use the
5526** [sqlite3_soft_heap_limit64()] interface rather than this one.
5528SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N);
5532** CAPI3REF: Extract Metadata About A Column Of A Table
5533** METHOD: sqlite3
5535** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
5536** information about column C of table T in database D
5537** on [database connection] X.)^  ^The sqlite3_table_column_metadata()
5538** interface returns SQLITE_OK and fills in the non-NULL pointers in
5539** the final five arguments with appropriate values if the specified
5540** column exists.  ^The sqlite3_table_column_metadata() interface returns
5541** SQLITE_ERROR and if the specified column does not exist.
5542** ^If the column-name parameter to sqlite3_table_column_metadata() is a
5543** NULL pointer, then this routine simply checks for the existance of the
5544** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
5545** does not.
5547** ^The column is identified by the second, third and fourth parameters to
5548** this function. ^(The second parameter is either the name of the database
5549** (i.e. "main", "temp", or an attached database) containing the specified
5550** table or NULL.)^ ^If it is NULL, then all attached databases are searched
5551** for the table using the same algorithm used by the database engine to
5552** resolve unqualified table references.
5554** ^The third and fourth parameters to this function are the table and column
5555** name of the desired column, respectively.
5557** ^Metadata is returned by writing to the memory locations passed as the 5th
5558** and subsequent parameters to this function. ^Any of these arguments may be
5559** NULL, in which case the corresponding element of metadata is omitted.
5561** ^(<blockquote>
5562** <table border="1">
5563** <tr><th> Parameter <th> Output<br>Type <th>  Description
5565** <tr><td> 5th <td> const char* <td> Data type
5566** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5567** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
5568** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
5569** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
5570** </table>
5571** </blockquote>)^
5573** ^The memory pointed to by the character pointers returned for the
5574** declaration type and collation sequence is valid until the next
5575** call to any SQLite API function.
5577** ^If the specified table is actually a view, an [error code] is returned.
5579** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
5580** is not a [WITHOUT ROWID] table and an
5581** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5582** parameters are set for the explicitly declared column. ^(If there is no
5583** [INTEGER PRIMARY KEY] column, then the outputs
5584** for the [rowid] are set as follows:
5586** <pre>
5587**     data type: "INTEGER"
5588**     collation sequence: "BINARY"
5589**     not null: 0
5590**     primary key: 1
5591**     auto increment: 0
5592** </pre>)^
5594** ^This function causes all database schemas to be read from disk and
5595** parsed, if that has not already been done, and returns an error if
5596** any errors are encountered while loading the schema.
5598SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
5599  sqlite3 *db,                /* Connection handle */
5600  const char *zDbName,        /* Database name or NULL */
5601  const char *zTableName,     /* Table name */
5602  const char *zColumnName,    /* Column name */
5603  char const **pzDataType,    /* OUTPUT: Declared data type */
5604  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
5605  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
5606  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
5607  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
5611** CAPI3REF: Load An Extension
5612** METHOD: sqlite3
5614** ^This interface loads an SQLite extension library from the named file.
5616** ^The sqlite3_load_extension() interface attempts to load an
5617** [SQLite extension] library contained in the file zFile.  If
5618** the file cannot be loaded directly, attempts are made to load
5619** with various operating-system specific extensions added.
5620** So for example, if "samplelib" cannot be loaded, then names like
5621** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5622** be tried also.
5624** ^The entry point is zProc.
5625** ^(zProc may be 0, in which case SQLite will try to come up with an
5626** entry point name on its own.  It first tries "sqlite3_extension_init".
5627** If that does not work, it constructs a name "sqlite3_X_init" where the
5628** X is consists of the lower-case equivalent of all ASCII alphabetic
5629** characters in the filename from the last "/" to the first following
5630** "." and omitting any initial "lib".)^
5631** ^The sqlite3_load_extension() interface returns
5632** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5633** ^If an error occurs and pzErrMsg is not 0, then the
5634** [sqlite3_load_extension()] interface shall attempt to
5635** fill *pzErrMsg with error message text stored in memory
5636** obtained from [sqlite3_malloc()]. The calling function
5637** should free this memory by calling [sqlite3_free()].
5639** ^Extension loading must be enabled using
5640** [sqlite3_enable_load_extension()] prior to calling this API,
5641** otherwise an error will be returned.
5643** See also the [load_extension() SQL function].
5645SQLITE_API int SQLITE_STDCALL sqlite3_load_extension(
5646  sqlite3 *db,          /* Load the extension into this database connection */
5647  const char *zFile,    /* Name of the shared library containing extension */
5648  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
5649  char **pzErrMsg       /* Put error message here if not 0 */
5653** CAPI3REF: Enable Or Disable Extension Loading
5654** METHOD: sqlite3
5656** ^So as not to open security holes in older applications that are
5657** unprepared to deal with [extension loading], and as a means of disabling
5658** [extension loading] while evaluating user-entered SQL, the following API
5659** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5661** ^Extension loading is off by default.
5662** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5663** to turn extension loading on and call it with onoff==0 to turn
5664** it back off again.
5666SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5669** CAPI3REF: Automatically Load Statically Linked Extensions
5671** ^This interface causes the xEntryPoint() function to be invoked for
5672** each new [database connection] that is created.  The idea here is that
5673** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5674** that is to be automatically loaded into all new database connections.
5676** ^(Even though the function prototype shows that xEntryPoint() takes
5677** no arguments and returns void, SQLite invokes xEntryPoint() with three
5678** arguments and expects and integer result as if the signature of the
5679** entry point where as follows:
5681** <blockquote><pre>
5682** &nbsp;  int xEntryPoint(
5683** &nbsp;    sqlite3 *db,
5684** &nbsp;    const char **pzErrMsg,
5685** &nbsp;    const struct sqlite3_api_routines *pThunk
5686** &nbsp;  );
5687** </pre></blockquote>)^
5689** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5690** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5691** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
5692** is NULL before calling the xEntryPoint().  ^SQLite will invoke
5693** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
5694** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5695** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5697** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5698** on the list of automatic extensions is a harmless no-op. ^No entry point
5699** will be called more than once for each database connection that is opened.
5701** See also: [sqlite3_reset_auto_extension()]
5702** and [sqlite3_cancel_auto_extension()]
5704SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void));
5707** CAPI3REF: Cancel Automatic Extension Loading
5709** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5710** initialization routine X that was registered using a prior call to
5711** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
5712** routine returns 1 if initialization routine X was successfully
5713** unregistered and it returns 0 if X was not on the list of initialization
5714** routines.
5716SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
5719** CAPI3REF: Reset Automatic Extension Loading
5721** ^This interface disables all automatic extensions previously
5722** registered using [sqlite3_auto_extension()].
5724SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void);
5727** The interface to the virtual-table mechanism is currently considered
5728** to be experimental.  The interface might change in incompatible ways.
5729** If this is a problem for you, do not use the interface at this time.
5731** When the virtual-table mechanism stabilizes, we will declare the
5732** interface fixed, support it indefinitely, and remove this comment.
5736** Structures used by the virtual table interface
5738typedef struct sqlite3_vtab sqlite3_vtab;
5739typedef struct sqlite3_index_info sqlite3_index_info;
5740typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5741typedef struct sqlite3_module sqlite3_module;
5744** CAPI3REF: Virtual Table Object
5745** KEYWORDS: sqlite3_module {virtual table module}
5747** This structure, sometimes called a "virtual table module",
5748** defines the implementation of a [virtual tables].
5749** This structure consists mostly of methods for the module.
5751** ^A virtual table module is created by filling in a persistent
5752** instance of this structure and passing a pointer to that instance
5753** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5754** ^The registration remains valid until it is replaced by a different
5755** module or until the [database connection] closes.  The content
5756** of this structure must not change while it is registered with
5757** any database connection.
5759struct sqlite3_module {
5760  int iVersion;
5761  int (*xCreate)(sqlite3*, void *pAux,
5762               int argc, const char *const*argv,
5763               sqlite3_vtab **ppVTab, char**);
5764  int (*xConnect)(sqlite3*, void *pAux,
5765               int argc, const char *const*argv,
5766               sqlite3_vtab **ppVTab, char**);
5767  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5768  int (*xDisconnect)(sqlite3_vtab *pVTab);
5769  int (*xDestroy)(sqlite3_vtab *pVTab);
5770  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5771  int (*xClose)(sqlite3_vtab_cursor*);
5772  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5773                int argc, sqlite3_value **argv);
5774  int (*xNext)(sqlite3_vtab_cursor*);
5775  int (*xEof)(sqlite3_vtab_cursor*);
5776  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5777  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5778  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5779  int (*xBegin)(sqlite3_vtab *pVTab);
5780  int (*xSync)(sqlite3_vtab *pVTab);
5781  int (*xCommit)(sqlite3_vtab *pVTab);
5782  int (*xRollback)(sqlite3_vtab *pVTab);
5783  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5784                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5785                       void **ppArg);
5786  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5787  /* The methods above are in version 1 of the sqlite_module object. Those
5788  ** below are for version 2 and greater. */
5789  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5790  int (*xRelease)(sqlite3_vtab *pVTab, int);
5791  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5795** CAPI3REF: Virtual Table Indexing Information
5796** KEYWORDS: sqlite3_index_info
5798** The sqlite3_index_info structure and its substructures is used as part
5799** of the [virtual table] interface to
5800** pass information into and receive the reply from the [xBestIndex]
5801** method of a [virtual table module].  The fields under **Inputs** are the
5802** inputs to xBestIndex and are read-only.  xBestIndex inserts its
5803** results into the **Outputs** fields.
5805** ^(The aConstraint[] array records WHERE clause constraints of the form:
5807** <blockquote>column OP expr</blockquote>
5809** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
5810** stored in aConstraint[].op using one of the
5812** ^(The index of the column is stored in
5813** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
5814** expr on the right-hand side can be evaluated (and thus the constraint
5815** is usable) and false if it cannot.)^
5817** ^The optimizer automatically inverts terms of the form "expr OP column"
5818** and makes other simplifications to the WHERE clause in an attempt to
5819** get as many WHERE clause terms into the form shown above as possible.
5820** ^The aConstraint[] array only reports WHERE clause terms that are
5821** relevant to the particular virtual table being queried.
5823** ^Information about the ORDER BY clause is stored in aOrderBy[].
5824** ^Each term of aOrderBy records a column of the ORDER BY clause.
5826** The [xBestIndex] method must fill aConstraintUsage[] with information
5827** about what parameters to pass to xFilter.  ^If argvIndex>0 then
5828** the right-hand side of the corresponding aConstraint[] is evaluated
5829** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
5830** is true, then the constraint is assumed to be fully handled by the
5831** virtual table and is not checked again by SQLite.)^
5833** ^The idxNum and idxPtr values are recorded and passed into the
5834** [xFilter] method.
5835** ^[sqlite3_free()] is used to free idxPtr if and only if
5836** needToFreeIdxPtr is true.
5838** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5839** the correct order to satisfy the ORDER BY clause so that no separate
5840** sorting step is required.
5842** ^The estimatedCost value is an estimate of the cost of a particular
5843** strategy. A cost of N indicates that the cost of the strategy is similar
5844** to a linear scan of an SQLite table with N rows. A cost of log(N)
5845** indicates that the expense of the operation is similar to that of a
5846** binary search on a unique indexed field of an SQLite table with N rows.
5848** ^The estimatedRows value is an estimate of the number of rows that
5849** will be returned by the strategy.
5851** The xBestIndex method may optionally populate the idxFlags field with a
5852** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
5853** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
5854** assumes that the strategy may visit at most one row.
5856** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
5857** SQLite also assumes that if a call to the xUpdate() method is made as
5858** part of the same statement to delete or update a virtual table row and the
5859** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
5860** any database changes. In other words, if the xUpdate() returns
5861** SQLITE_CONSTRAINT, the database contents must be exactly as they were
5862** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
5863** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
5864** the xUpdate method are automatically rolled back by SQLite.
5866** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5867** structure for SQLite version 3.8.2. If a virtual table extension is
5868** used with an SQLite version earlier than 3.8.2, the results of attempting
5869** to read or write the estimatedRows field are undefined (but are likely
5870** to included crashing the application). The estimatedRows field should
5871** therefore only be used if [sqlite3_libversion_number()] returns a
5872** value greater than or equal to 3008002. Similarly, the idxFlags field
5873** was added for version 3.9.0. It may therefore only be used if
5874** sqlite3_libversion_number() returns a value greater than or equal to
5875** 3009000.
5877struct sqlite3_index_info {
5878  /* Inputs */
5879  int nConstraint;           /* Number of entries in aConstraint */
5880  struct sqlite3_index_constraint {
5881     int iColumn;              /* Column on left-hand side of constraint */
5882     unsigned char op;         /* Constraint operator */
5883     unsigned char usable;     /* True if this constraint is usable */
5884     int iTermOffset;          /* Used internally - xBestIndex should ignore */
5885  } *aConstraint;            /* Table of WHERE clause constraints */
5886  int nOrderBy;              /* Number of terms in the ORDER BY clause */
5887  struct sqlite3_index_orderby {
5888     int iColumn;              /* Column number */
5889     unsigned char desc;       /* True for DESC.  False for ASC. */
5890  } *aOrderBy;               /* The ORDER BY clause */
5891  /* Outputs */
5892  struct sqlite3_index_constraint_usage {
5893    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
5894    unsigned char omit;      /* Do not code a test for this constraint */
5895  } *aConstraintUsage;
5896  int idxNum;                /* Number used to identify the index */
5897  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
5898  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
5899  int orderByConsumed;       /* True if output is already ordered */
5900  double estimatedCost;           /* Estimated cost of using this index */
5901  /* Fields below are only available in SQLite 3.8.2 and later */
5902  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
5903  /* Fields below are only available in SQLite 3.9.0 and later */
5904  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
5908** CAPI3REF: Virtual Table Scan Flags
5910#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */
5913** CAPI3REF: Virtual Table Constraint Operator Codes
5915** These macros defined the allowed values for the
5916** [sqlite3_index_info].aConstraint[].op field.  Each value represents
5917** an operator that is part of a constraint term in the wHERE clause of
5918** a query that uses a [virtual table].
5928** CAPI3REF: Register A Virtual Table Implementation
5929** METHOD: sqlite3
5931** ^These routines are used to register a new [virtual table module] name.
5932** ^Module names must be registered before
5933** creating a new [virtual table] using the module and before using a
5934** preexisting [virtual table] for the module.
5936** ^The module name is registered on the [database connection] specified
5937** by the first parameter.  ^The name of the module is given by the
5938** second parameter.  ^The third parameter is a pointer to
5939** the implementation of the [virtual table module].   ^The fourth
5940** parameter is an arbitrary client data pointer that is passed through
5941** into the [xCreate] and [xConnect] methods of the virtual table module
5942** when a new virtual table is be being created or reinitialized.
5944** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5945** is a pointer to a destructor for the pClientData.  ^SQLite will
5946** invoke the destructor function (if it is not NULL) when SQLite
5947** no longer needs the pClientData pointer.  ^The destructor will also
5948** be invoked if the call to sqlite3_create_module_v2() fails.
5949** ^The sqlite3_create_module()
5950** interface is equivalent to sqlite3_create_module_v2() with a NULL
5951** destructor.
5953SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
5954  sqlite3 *db,               /* SQLite connection to register module with */
5955  const char *zName,         /* Name of the module */
5956  const sqlite3_module *p,   /* Methods for the module */
5957  void *pClientData          /* Client data for xCreate/xConnect */
5959SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
5960  sqlite3 *db,               /* SQLite connection to register module with */
5961  const char *zName,         /* Name of the module */
5962  const sqlite3_module *p,   /* Methods for the module */
5963  void *pClientData,         /* Client data for xCreate/xConnect */
5964  void(*xDestroy)(void*)     /* Module destructor function */
5968** CAPI3REF: Virtual Table Instance Object
5969** KEYWORDS: sqlite3_vtab
5971** Every [virtual table module] implementation uses a subclass
5972** of this object to describe a particular instance
5973** of the [virtual table].  Each subclass will
5974** be tailored to the specific needs of the module implementation.
5975** The purpose of this superclass is to define certain fields that are
5976** common to all module implementations.
5978** ^Virtual tables methods can set an error message by assigning a
5979** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
5980** take care that any prior string is freed by a call to [sqlite3_free()]
5981** prior to assigning a new string to zErrMsg.  ^After the error message
5982** is delivered up to the client application, the string will be automatically
5983** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5985struct sqlite3_vtab {
5986  const sqlite3_module *pModule;  /* The module for this virtual table */
5987  int nRef;                       /* Number of open cursors */
5988  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
5989  /* Virtual table implementations will typically add additional fields */
5993** CAPI3REF: Virtual Table Cursor Object
5994** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5996** Every [virtual table module] implementation uses a subclass of the
5997** following structure to describe cursors that point into the
5998** [virtual table] and are used
5999** to loop through the virtual table.  Cursors are created using the
6000** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6001** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
6002** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6003** of the module.  Each module implementation will define
6004** the content of a cursor structure to suit its own needs.
6006** This superclass exists in order to define fields of the cursor that
6007** are common to all implementations.
6009struct sqlite3_vtab_cursor {
6010  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
6011  /* Virtual table implementations will typically add additional fields */
6015** CAPI3REF: Declare The Schema Of A Virtual Table
6017** ^The [xCreate] and [xConnect] methods of a
6018** [virtual table module] call this interface
6019** to declare the format (the names and datatypes of the columns) of
6020** the virtual tables they implement.
6022SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6025** CAPI3REF: Overload A Function For A Virtual Table
6026** METHOD: sqlite3
6028** ^(Virtual tables can provide alternative implementations of functions
6029** using the [xFindFunction] method of the [virtual table module].
6030** But global versions of those functions
6031** must exist in order to be overloaded.)^
6033** ^(This API makes sure a global version of a function with a particular
6034** name and number of parameters exists.  If no such function exists
6035** before this API is called, a new function is created.)^  ^The implementation
6036** of the new function always causes an exception to be thrown.  So
6037** the new function is not good for anything by itself.  Its only
6038** purpose is to be a placeholder function that can be overloaded
6039** by a [virtual table].
6041SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6044** The interface to the virtual-table mechanism defined above (back up
6045** to a comment remarkably similar to this one) is currently considered
6046** to be experimental.  The interface might change in incompatible ways.
6047** If this is a problem for you, do not use the interface at this time.
6049** When the virtual-table mechanism stabilizes, we will declare the
6050** interface fixed, support it indefinitely, and remove this comment.
6054** CAPI3REF: A Handle To An Open BLOB
6055** KEYWORDS: {BLOB handle} {BLOB handles}
6057** An instance of this object represents an open BLOB on which
6058** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6059** ^Objects of this type are created by [sqlite3_blob_open()]
6060** and destroyed by [sqlite3_blob_close()].
6061** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6062** can be used to read or write small subsections of the BLOB.
6063** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6065typedef struct sqlite3_blob sqlite3_blob;
6068** CAPI3REF: Open A BLOB For Incremental I/O
6069** METHOD: sqlite3
6070** CONSTRUCTOR: sqlite3_blob
6072** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6073** in row iRow, column zColumn, table zTable in database zDb;
6074** in other words, the same BLOB that would be selected by:
6076** <pre>
6077**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6078** </pre>)^
6080** ^(Parameter zDb is not the filename that contains the database, but
6081** rather the symbolic name of the database. For attached databases, this is
6082** the name that appears after the AS keyword in the [ATTACH] statement.
6083** For the main database file, the database name is "main". For TEMP
6084** tables, the database name is "temp".)^
6086** ^If the flags parameter is non-zero, then the BLOB is opened for read
6087** and write access. ^If the flags parameter is zero, the BLOB is opened for
6088** read-only access.
6090** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6091** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6092** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6093** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6094** on *ppBlob after this function it returns.
6096** This function fails with SQLITE_ERROR if any of the following are true:
6097** <ul>
6098**   <li> ^(Database zDb does not exist)^,
6099**   <li> ^(Table zTable does not exist within database zDb)^,
6100**   <li> ^(Table zTable is a WITHOUT ROWID table)^,
6101**   <li> ^(Column zColumn does not exist)^,
6102**   <li> ^(Row iRow is not present in the table)^,
6103**   <li> ^(The specified column of row iRow contains a value that is not
6104**         a TEXT or BLOB value)^,
6105**   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6106**         constraint and the blob is being opened for read/write access)^,
6107**   <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6108**         column zColumn is part of a [child key] definition and the blob is
6109**         being opened for read/write access)^.
6110** </ul>
6112** ^Unless it returns SQLITE_MISUSE, this function sets the
6113** [database connection] error code and message accessible via
6114** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6117** ^(If the row that a BLOB handle points to is modified by an
6118** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6119** then the BLOB handle is marked as "expired".
6120** This is true if any column of the row is changed, even a column
6121** other than the one the BLOB handle is open on.)^
6122** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6123** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6124** ^(Changes written into a BLOB prior to the BLOB expiring are not
6125** rolled back by the expiration of the BLOB.  Such changes will eventually
6126** commit if the transaction continues to completion.)^
6128** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6129** the opened blob.  ^The size of a blob may not be changed by this
6130** interface.  Use the [UPDATE] SQL command to change the size of a
6131** blob.
6133** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6134** and the built-in [zeroblob] SQL function may be used to create a
6135** zero-filled blob to read or write using the incremental-blob interface.
6137** To avoid a resource leak, every open [BLOB handle] should eventually
6138** be released by a call to [sqlite3_blob_close()].
6140SQLITE_API int SQLITE_STDCALL sqlite3_blob_open(
6141  sqlite3*,
6142  const char *zDb,
6143  const char *zTable,
6144  const char *zColumn,
6145  sqlite3_int64 iRow,
6146  int flags,
6147  sqlite3_blob **ppBlob
6151** CAPI3REF: Move a BLOB Handle to a New Row
6152** METHOD: sqlite3_blob
6154** ^This function is used to move an existing blob handle so that it points
6155** to a different row of the same database table. ^The new row is identified
6156** by the rowid value passed as the second argument. Only the row can be
6157** changed. ^The database, table and column on which the blob handle is open
6158** remain the same. Moving an existing blob handle to a new row can be
6159** faster than closing the existing handle and opening a new one.
6161** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6162** it must exist and there must be either a blob or text value stored in
6163** the nominated column.)^ ^If the new row is not present in the table, or if
6164** it does not contain a blob or text value, or if another error occurs, an
6165** SQLite error code is returned and the blob handle is considered aborted.
6166** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6167** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6168** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6169** always returns zero.
6171** ^This function sets the database handle error code and message.
6173SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6176** CAPI3REF: Close A BLOB Handle
6177** DESTRUCTOR: sqlite3_blob
6179** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6180** unconditionally.  Even if this routine returns an error code, the
6181** handle is still closed.)^
6183** ^If the blob handle being closed was opened for read-write access, and if
6184** the database is in auto-commit mode and there are no other open read-write
6185** blob handles or active write statements, the current transaction is
6186** committed. ^If an error occurs while committing the transaction, an error
6187** code is returned and the transaction rolled back.
6189** Calling this function with an argument that is not a NULL pointer or an
6190** open blob handle results in undefined behaviour. ^Calling this routine
6191** with a null pointer (such as would be returned by a failed call to
6192** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6193** is passed a valid open blob handle, the values returned by the
6194** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6196SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *);
6199** CAPI3REF: Return The Size Of An Open BLOB
6200** METHOD: sqlite3_blob
6202** ^Returns the size in bytes of the BLOB accessible via the
6203** successfully opened [BLOB handle] in its only argument.  ^The
6204** incremental blob I/O routines can only read or overwriting existing
6205** blob content; they cannot change the size of a blob.
6207** This routine only works on a [BLOB handle] which has been created
6208** by a prior successful call to [sqlite3_blob_open()] and which has not
6209** been closed by [sqlite3_blob_close()].  Passing any other pointer in
6210** to this routine results in undefined and probably undesirable behavior.
6212SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *);
6215** CAPI3REF: Read Data From A BLOB Incrementally
6216** METHOD: sqlite3_blob
6218** ^(This function is used to read data from an open [BLOB handle] into a
6219** caller-supplied buffer. N bytes of data are copied into buffer Z
6220** from the open BLOB, starting at offset iOffset.)^
6222** ^If offset iOffset is less than N bytes from the end of the BLOB,
6223** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
6224** less than zero, [SQLITE_ERROR] is returned and no data is read.
6225** ^The size of the blob (and hence the maximum value of N+iOffset)
6226** can be determined using the [sqlite3_blob_bytes()] interface.
6228** ^An attempt to read from an expired [BLOB handle] fails with an
6229** error code of [SQLITE_ABORT].
6231** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6232** Otherwise, an [error code] or an [extended error code] is returned.)^
6234** This routine only works on a [BLOB handle] which has been created
6235** by a prior successful call to [sqlite3_blob_open()] and which has not
6236** been closed by [sqlite3_blob_close()].  Passing any other pointer in
6237** to this routine results in undefined and probably undesirable behavior.
6239** See also: [sqlite3_blob_write()].
6241SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6244** CAPI3REF: Write Data Into A BLOB Incrementally
6245** METHOD: sqlite3_blob
6247** ^(This function is used to write data into an open [BLOB handle] from a
6248** caller-supplied buffer. N bytes of data are copied from the buffer Z
6249** into the open BLOB, starting at offset iOffset.)^
6251** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6252** Otherwise, an  [error code] or an [extended error code] is returned.)^
6253** ^Unless SQLITE_MISUSE is returned, this function sets the
6254** [database connection] error code and message accessible via
6255** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6257** ^If the [BLOB handle] passed as the first argument was not opened for
6258** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6259** this function returns [SQLITE_READONLY].
6261** This function may only modify the contents of the BLOB; it is
6262** not possible to increase the size of a BLOB using this API.
6263** ^If offset iOffset is less than N bytes from the end of the BLOB,
6264** [SQLITE_ERROR] is returned and no data is written. The size of the
6265** BLOB (and hence the maximum value of N+iOffset) can be determined
6266** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6267** than zero [SQLITE_ERROR] is returned and no data is written.
6269** ^An attempt to write to an expired [BLOB handle] fails with an
6270** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
6271** before the [BLOB handle] expired are not rolled back by the
6272** expiration of the handle, though of course those changes might
6273** have been overwritten by the statement that expired the BLOB handle
6274** or by other independent statements.
6276** This routine only works on a [BLOB handle] which has been created
6277** by a prior successful call to [sqlite3_blob_open()] and which has not
6278** been closed by [sqlite3_blob_close()].  Passing any other pointer in
6279** to this routine results in undefined and probably undesirable behavior.
6281** See also: [sqlite3_blob_read()].
6283SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6286** CAPI3REF: Virtual File System Objects
6288** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6289** that SQLite uses to interact
6290** with the underlying operating system.  Most SQLite builds come with a
6291** single default VFS that is appropriate for the host computer.
6292** New VFSes can be registered and existing VFSes can be unregistered.
6293** The following interfaces are provided.
6295** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6296** ^Names are case sensitive.
6297** ^Names are zero-terminated UTF-8 strings.
6298** ^If there is no match, a NULL pointer is returned.
6299** ^If zVfsName is NULL then the default VFS is returned.
6301** ^New VFSes are registered with sqlite3_vfs_register().
6302** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6303** ^The same VFS can be registered multiple times without injury.
6304** ^To make an existing VFS into the default VFS, register it again
6305** with the makeDflt flag set.  If two different VFSes with the
6306** same name are registered, the behavior is undefined.  If a
6307** VFS is registered with a name that is NULL or an empty string,
6308** then the behavior is undefined.
6310** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6311** ^(If the default VFS is unregistered, another VFS is chosen as
6312** the default.  The choice for the new VFS is arbitrary.)^
6314SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName);
6315SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6316SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*);
6319** CAPI3REF: Mutexes
6321** The SQLite core uses these routines for thread
6322** synchronization. Though they are intended for internal
6323** use by SQLite, code that links against SQLite is
6324** permitted to use any of these routines.
6326** The SQLite source code contains multiple implementations
6327** of these mutex routines.  An appropriate implementation
6328** is selected automatically at compile-time.  The following
6329** implementations are available in the SQLite core:
6331** <ul>
6333** <li>   SQLITE_MUTEX_W32
6334** <li>   SQLITE_MUTEX_NOOP
6335** </ul>
6337** The SQLITE_MUTEX_NOOP implementation is a set of routines
6338** that does no real locking and is appropriate for use in
6339** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
6340** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6341** and Windows.
6343** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6344** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6345** implementation is included with the library. In this case the
6346** application must supply a custom mutex implementation using the
6347** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6348** before calling sqlite3_initialize() or any other public sqlite3_
6349** function that calls sqlite3_initialize().
6351** ^The sqlite3_mutex_alloc() routine allocates a new
6352** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6353** routine returns NULL if it is unable to allocate the requested
6354** mutex.  The argument to sqlite3_mutex_alloc() must one of these
6355** integer constants:
6357** <ul>
6358** <li>  SQLITE_MUTEX_FAST
6372** </ul>
6374** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6375** cause sqlite3_mutex_alloc() to create
6376** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6377** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6378** The mutex implementation does not need to make a distinction
6379** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6380** not want to.  SQLite will only request a recursive mutex in
6381** cases where it really needs one.  If a faster non-recursive mutex
6382** implementation is available on the host platform, the mutex subsystem
6383** might return such a mutex in response to SQLITE_MUTEX_FAST.
6385** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6387** a pointer to a static preexisting mutex.  ^Nine static mutexes are
6388** used by the current version of SQLite.  Future versions of SQLite
6389** may add additional static mutexes.  Static mutexes are for internal
6390** use by SQLite only.  Applications that use SQLite mutexes should
6391** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6394** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6395** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6396** returns a different mutex on every call.  ^For the static
6397** mutex types, the same mutex is returned on every call that has
6398** the same type number.
6400** ^The sqlite3_mutex_free() routine deallocates a previously
6401** allocated dynamic mutex.  Attempting to deallocate a static
6402** mutex results in undefined behavior.
6404** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6405** to enter a mutex.  ^If another thread is already within the mutex,
6406** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6407** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6408** upon successful entry.  ^(Mutexes created using
6409** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6410** In such cases, the
6411** mutex must be exited an equal number of times before another thread
6412** can enter.)^  If the same thread tries to enter any mutex other
6413** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6415** ^(Some systems (for example, Windows 95) do not support the operation
6416** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
6417** will always return SQLITE_BUSY. The SQLite core only ever uses
6418** sqlite3_mutex_try() as an optimization so this is acceptable
6419** behavior.)^
6421** ^The sqlite3_mutex_leave() routine exits a mutex that was
6422** previously entered by the same thread.   The behavior
6423** is undefined if the mutex is not currently entered by the
6424** calling thread or is not currently allocated.
6426** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6427** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6428** behave as no-ops.
6430** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6432SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int);
6433SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*);
6434SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*);
6435SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*);
6436SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*);
6439** CAPI3REF: Mutex Methods Object
6441** An instance of this structure defines the low-level routines
6442** used to allocate and use mutexes.
6444** Usually, the default mutex implementations provided by SQLite are
6445** sufficient, however the application has the option of substituting a custom
6446** implementation for specialized deployments or systems for which SQLite
6447** does not provide a suitable implementation. In this case, the application
6448** creates and populates an instance of this structure to pass
6449** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6450** Additionally, an instance of this structure can be used as an
6451** output variable when querying the system for the current mutex
6452** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6454** ^The xMutexInit method defined by this structure is invoked as
6455** part of system initialization by the sqlite3_initialize() function.
6456** ^The xMutexInit routine is called by SQLite exactly once for each
6457** effective call to [sqlite3_initialize()].
6459** ^The xMutexEnd method defined by this structure is invoked as
6460** part of system shutdown by the sqlite3_shutdown() function. The
6461** implementation of this method is expected to release all outstanding
6462** resources obtained by the mutex methods implementation, especially
6463** those obtained by the xMutexInit method.  ^The xMutexEnd()
6464** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6466** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6467** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6468** xMutexNotheld) implement the following interfaces (respectively):
6470** <ul>
6471**   <li>  [sqlite3_mutex_alloc()] </li>
6472**   <li>  [sqlite3_mutex_free()] </li>
6473**   <li>  [sqlite3_mutex_enter()] </li>
6474**   <li>  [sqlite3_mutex_try()] </li>
6475**   <li>  [sqlite3_mutex_leave()] </li>
6476**   <li>  [sqlite3_mutex_held()] </li>
6477**   <li>  [sqlite3_mutex_notheld()] </li>
6478** </ul>)^
6480** The only difference is that the public sqlite3_XXX functions enumerated
6481** above silently ignore any invocations that pass a NULL pointer instead
6482** of a valid mutex handle. The implementations of the methods defined
6483** by this structure are not required to handle this case, the results
6484** of passing a NULL pointer instead of a valid mutex handle are undefined
6485** (i.e. it is acceptable to provide an implementation that segfaults if
6486** it is passed a NULL pointer).
6488** The xMutexInit() method must be threadsafe.  It must be harmless to
6489** invoke xMutexInit() multiple times within the same process and without
6490** intervening calls to xMutexEnd().  Second and subsequent calls to
6491** xMutexInit() must be no-ops.
6493** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6494** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
6495** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
6496** memory allocation for a fast or recursive mutex.
6498** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6499** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6500** If xMutexInit fails in any way, it is expected to clean up after itself
6501** prior to returning.
6503typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6504struct sqlite3_mutex_methods {
6505  int (*xMutexInit)(void);
6506  int (*xMutexEnd)(void);
6507  sqlite3_mutex *(*xMutexAlloc)(int);
6508  void (*xMutexFree)(sqlite3_mutex *);
6509  void (*xMutexEnter)(sqlite3_mutex *);
6510  int (*xMutexTry)(sqlite3_mutex *);
6511  void (*xMutexLeave)(sqlite3_mutex *);
6512  int (*xMutexHeld)(sqlite3_mutex *);
6513  int (*xMutexNotheld)(sqlite3_mutex *);
6517** CAPI3REF: Mutex Verification Routines
6519** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6520** are intended for use inside assert() statements.  The SQLite core
6521** never uses these routines except inside an assert() and applications
6522** are advised to follow the lead of the core.  The SQLite core only
6523** provides implementations for these routines when it is compiled
6524** with the SQLITE_DEBUG flag.  External mutex implementations
6525** are only required to provide these routines if SQLITE_DEBUG is
6526** defined and if NDEBUG is not defined.
6528** These routines should return true if the mutex in their argument
6529** is held or not held, respectively, by the calling thread.
6531** The implementation is not required to provide versions of these
6532** routines that actually work. If the implementation does not provide working
6533** versions of these routines, it should at least provide stubs that always
6534** return true so that one does not get spurious assertion failures.
6536** If the argument to sqlite3_mutex_held() is a NULL pointer then
6537** the routine should return 1.   This seems counter-intuitive since
6538** clearly the mutex cannot be held if it does not exist.  But
6539** the reason the mutex does not exist is because the build is not
6540** using mutexes.  And we do not want the assert() containing the
6541** call to sqlite3_mutex_held() to fail, so a non-zero return is
6542** the appropriate thing to do.  The sqlite3_mutex_notheld()
6543** interface should also return 1 when given a NULL pointer.
6545#ifndef NDEBUG
6546SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*);
6547SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*);
6551** CAPI3REF: Mutex Types
6553** The [sqlite3_mutex_alloc()] interface takes a single argument
6554** which is one of these integer constants.
6556** The set of static mutexes may change from one SQLite release to the
6557** next.  Applications that override the built-in mutex logic must be
6558** prepared to accommodate additional static mutexes.
6560#define SQLITE_MUTEX_FAST             0
6561#define SQLITE_MUTEX_RECURSIVE        1
6563#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
6564#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
6565#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
6566#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
6567#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
6568#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
6569#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
6570#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
6571#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
6572#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
6573#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
6574#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
6575#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */
6578** CAPI3REF: Retrieve the mutex for a database connection
6579** METHOD: sqlite3
6581** ^This interface returns a pointer the [sqlite3_mutex] object that
6582** serializes access to the [database connection] given in the argument
6583** when the [threading mode] is Serialized.
6584** ^If the [threading mode] is Single-thread or Multi-thread then this
6585** routine returns a NULL pointer.
6587SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*);
6590** CAPI3REF: Low-Level Control Of Database Files
6591** METHOD: sqlite3
6593** ^The [sqlite3_file_control()] interface makes a direct call to the
6594** xFileControl method for the [sqlite3_io_methods] object associated
6595** with a particular database identified by the second argument. ^The
6596** name of the database is "main" for the main database or "temp" for the
6597** TEMP database, or the name that appears after the AS keyword for
6598** databases that are added using the [ATTACH] SQL command.
6599** ^A NULL pointer can be used in place of "main" to refer to the
6600** main database file.
6601** ^The third and fourth parameters to this routine
6602** are passed directly through to the second and third parameters of
6603** the xFileControl method.  ^The return value of the xFileControl
6604** method becomes the return value of this routine.
6606** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6607** a pointer to the underlying [sqlite3_file] object to be written into
6608** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
6609** case is a short-circuit path which does not actually invoke the
6610** underlying sqlite3_io_methods.xFileControl method.
6612** ^If the second parameter (zDbName) does not match the name of any
6613** open database file, then SQLITE_ERROR is returned.  ^This error
6614** code is not remembered and will not be recalled by [sqlite3_errcode()]
6615** or [sqlite3_errmsg()].  The underlying xFileControl method might
6616** also return SQLITE_ERROR.  There is no way to distinguish between
6617** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6618** xFileControl method.
6622SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6625** CAPI3REF: Testing Interface
6627** ^The sqlite3_test_control() interface is used to read out internal
6628** state of SQLite and to inject faults into SQLite for testing
6629** purposes.  ^The first parameter is an operation code that determines
6630** the number, meaning, and operation of all subsequent parameters.
6632** This interface is not for use by applications.  It exists solely
6633** for verifying the correct operation of the SQLite library.  Depending
6634** on how the SQLite library is compiled, this interface might not exist.
6636** The details of the operation codes, their meanings, the parameters
6637** they take, and what they do are all subject to change without notice.
6638** Unlike most of the SQLite API, this function is not guaranteed to
6639** operate consistently from one release to the next.
6641SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...);
6644** CAPI3REF: Testing Interface Operation Codes
6646** These constants are the valid operation code parameters used
6647** as the first argument to [sqlite3_test_control()].
6649** These parameters and their meanings are subject to change
6650** without notice.  These values are for testing purposes only.
6651** Applications should not use any of these parameters or the
6652** [sqlite3_test_control()] interface.
6654#define SQLITE_TESTCTRL_FIRST                    5
6655#define SQLITE_TESTCTRL_PRNG_SAVE                5
6656#define SQLITE_TESTCTRL_PRNG_RESTORE             6
6657#define SQLITE_TESTCTRL_PRNG_RESET               7
6658#define SQLITE_TESTCTRL_BITVEC_TEST              8
6659#define SQLITE_TESTCTRL_FAULT_INSTALL            9
6661#define SQLITE_TESTCTRL_PENDING_BYTE            11
6662#define SQLITE_TESTCTRL_ASSERT                  12
6663#define SQLITE_TESTCTRL_ALWAYS                  13
6664#define SQLITE_TESTCTRL_RESERVE                 14
6665#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
6666#define SQLITE_TESTCTRL_ISKEYWORD               16
6667#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
6669#define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
6670#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
6671#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
6672#define SQLITE_TESTCTRL_BYTEORDER               22
6673#define SQLITE_TESTCTRL_ISINIT                  23
6674#define SQLITE_TESTCTRL_SORTER_MMAP             24
6675#define SQLITE_TESTCTRL_IMPOSTER                25
6676#define SQLITE_TESTCTRL_LAST                    25
6679** CAPI3REF: SQLite Runtime Status
6681** ^These interfaces are used to retrieve runtime status information
6682** about the performance of SQLite, and optionally to reset various
6683** highwater marks.  ^The first argument is an integer code for
6684** the specific parameter to measure.  ^(Recognized integer codes
6685** are of the form [status parameters | SQLITE_STATUS_...].)^
6686** ^The current value of the parameter is returned into *pCurrent.
6687** ^The highest recorded value is returned in *pHighwater.  ^If the
6688** resetFlag is true, then the highest record value is reset after
6689** *pHighwater is written.  ^(Some parameters do not record the highest
6690** value.  For those parameters
6691** nothing is written into *pHighwater and the resetFlag is ignored.)^
6692** ^(Other parameters record only the highwater mark and not the current
6693** value.  For these latter parameters nothing is written into *pCurrent.)^
6695** ^The sqlite3_status() and sqlite3_status64() routines return
6696** SQLITE_OK on success and a non-zero [error code] on failure.
6698** If either the current value or the highwater mark is too large to
6699** be represented by a 32-bit integer, then the values returned by
6700** sqlite3_status() are undefined.
6702** See also: [sqlite3_db_status()]
6704SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6705SQLITE_API int SQLITE_STDCALL sqlite3_status64(
6706  int op,
6707  sqlite3_int64 *pCurrent,
6708  sqlite3_int64 *pHighwater,
6709  int resetFlag
6714** CAPI3REF: Status Parameters
6715** KEYWORDS: {status parameters}
6717** These integer constants designate various run-time status parameters
6718** that can be returned by [sqlite3_status()].
6720** <dl>
6722** <dd>This parameter is the current amount of memory checked out
6723** using [sqlite3_malloc()], either directly or indirectly.  The
6724** figure includes calls made to [sqlite3_malloc()] by the application
6725** and internal memory usage by the SQLite library.  Scratch memory
6726** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6727** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6728** this parameter.  The amount returned is the sum of the allocation
6729** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6732** <dd>This parameter records the largest memory allocation request
6733** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6734** internal equivalents).  Only the value returned in the
6735** *pHighwater parameter to [sqlite3_status()] is of interest.
6736** The value written into the *pCurrent parameter is undefined.</dd>)^
6739** <dd>This parameter records the number of separate memory allocations
6740** currently checked out.</dd>)^
6743** <dd>This parameter returns the number of pages used out of the
6744** [pagecache memory allocator] that was configured using
6746** value returned is in pages, not in bytes.</dd>)^
6750** <dd>This parameter returns the number of bytes of page cache
6751** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6752** buffer and where forced to overflow to [sqlite3_malloc()].  The
6753** returned value includes allocations that overflowed because they
6754** where too large (they were larger than the "sz" parameter to
6755** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6756** no space was left in the page cache.</dd>)^
6759** <dd>This parameter records the largest memory allocation request
6760** handed to [pagecache memory allocator].  Only the value returned in the
6761** *pHighwater parameter to [sqlite3_status()] is of interest.
6762** The value written into the *pCurrent parameter is undefined.</dd>)^
6765** <dd>This parameter returns the number of allocations used out of the
6766** [scratch memory allocator] configured using
6767** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
6768** in bytes.  Since a single thread may only have one scratch allocation
6769** outstanding at time, this parameter also reports the number of threads
6770** using scratch memory at the same time.</dd>)^
6773** <dd>This parameter returns the number of bytes of scratch memory
6774** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6775** buffer and where forced to overflow to [sqlite3_malloc()].  The values
6776** returned include overflows because the requested allocation was too
6777** larger (that is, because the requested allocation was larger than the
6778** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6779** slots were available.
6780** </dd>)^
6783** <dd>This parameter records the largest memory allocation request
6784** handed to [scratch memory allocator].  Only the value returned in the
6785** *pHighwater parameter to [sqlite3_status()] is of interest.
6786** The value written into the *pCurrent parameter is undefined.</dd>)^
6789** <dd>This parameter records the deepest parser stack.  It is only
6790** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6791** </dl>
6793** New status parameters may be added from time to time.
6795#define SQLITE_STATUS_MEMORY_USED          0
6798#define SQLITE_STATUS_SCRATCH_USED         3
6800#define SQLITE_STATUS_MALLOC_SIZE          5
6801#define SQLITE_STATUS_PARSER_STACK         6
6803#define SQLITE_STATUS_SCRATCH_SIZE         8
6804#define SQLITE_STATUS_MALLOC_COUNT         9
6807** CAPI3REF: Database Connection Status
6808** METHOD: sqlite3
6810** ^This interface is used to retrieve runtime status information
6811** about a single [database connection].  ^The first argument is the
6812** database connection object to be interrogated.  ^The second argument
6813** is an integer constant, taken from the set of
6814** [SQLITE_DBSTATUS options], that
6815** determines the parameter to interrogate.  The set of
6816** [SQLITE_DBSTATUS options] is likely
6817** to grow in future releases of SQLite.
6819** ^The current value of the requested parameter is written into *pCur
6820** and the highest instantaneous value is written into *pHiwtr.  ^If
6821** the resetFlg is true, then the highest instantaneous value is
6822** reset back down to the current value.
6824** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6825** non-zero [error code] on failure.
6827** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6829SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6832** CAPI3REF: Status Parameters for database connections
6835** These constants are the available integer "verbs" that can be passed as
6836** the second argument to the [sqlite3_db_status()] interface.
6838** New verbs may be added in future releases of SQLite. Existing verbs
6839** might be discontinued. Applications should check the return code from
6840** [sqlite3_db_status()] to make sure that the call worked.
6841** The [sqlite3_db_status()] interface will return a non-zero error code
6842** if a discontinued or unsupported verb is invoked.
6844** <dl>
6846** <dd>This parameter returns the number of lookaside memory slots currently
6847** checked out.</dd>)^
6850** <dd>This parameter returns the number malloc attempts that were
6851** satisfied using lookaside memory. Only the high-water value is meaningful;
6852** the current value is always zero.)^
6856** <dd>This parameter returns the number malloc attempts that might have
6857** been satisfied using lookaside memory but failed due to the amount of
6858** memory requested being larger than the lookaside slot size.
6859** Only the high-water value is meaningful;
6860** the current value is always zero.)^
6864** <dd>This parameter returns the number malloc attempts that might have
6865** been satisfied using lookaside memory but failed due to all lookaside
6866** memory already being in use.
6867** Only the high-water value is meaningful;
6868** the current value is always zero.)^
6871** <dd>This parameter returns the approximate number of bytes of heap
6872** memory used by all pager caches associated with the database connection.)^
6873** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6876** <dd>This parameter returns the approximate number of bytes of heap
6877** memory used to store the schema for all databases associated
6878** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6879** ^The full amount of memory used by the schemas is reported, even if the
6880** schema memory is shared with other database connections due to
6881** [shared cache mode] being enabled.
6882** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6885** <dd>This parameter returns the approximate number of bytes of heap
6886** and lookaside memory used by all prepared statements associated with
6887** the database connection.)^
6888** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6889** </dd>
6892** <dd>This parameter returns the number of pager cache hits that have
6893** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
6894** is always 0.
6895** </dd>
6898** <dd>This parameter returns the number of pager cache misses that have
6899** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
6900** is always 0.
6901** </dd>
6904** <dd>This parameter returns the number of dirty cache entries that have
6905** been written to disk. Specifically, the number of pages written to the
6906** wal file in wal mode databases, or the number of pages written to the
6907** database file in rollback mode databases. Any pages written as part of
6908** transaction rollback or database recovery operations are not included.
6909** If an IO or other error occurs while writing a page to disk, the effect
6910** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
6911** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
6912** </dd>
6915** <dd>This parameter returns zero for the current value if and only if
6916** all foreign key constraints (deferred or immediate) have been
6917** resolved.)^  ^The highwater mark is always 0.
6918** </dd>
6919** </dl>
6922#define SQLITE_DBSTATUS_CACHE_USED           1
6923#define SQLITE_DBSTATUS_SCHEMA_USED          2
6924#define SQLITE_DBSTATUS_STMT_USED            3
6928#define SQLITE_DBSTATUS_CACHE_HIT            7
6929#define SQLITE_DBSTATUS_CACHE_MISS           8
6930#define SQLITE_DBSTATUS_CACHE_WRITE          9
6931#define SQLITE_DBSTATUS_DEFERRED_FKS        10
6932#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
6936** CAPI3REF: Prepared Statement Status
6937** METHOD: sqlite3_stmt
6939** ^(Each prepared statement maintains various
6940** [SQLITE_STMTSTATUS counters] that measure the number
6941** of times it has performed specific operations.)^  These counters can
6942** be used to monitor the performance characteristics of the prepared
6943** statements.  For example, if the number of table steps greatly exceeds
6944** the number of table searches or result rows, that would tend to indicate
6945** that the prepared statement is using a full table scan rather than
6946** an index.
6948** ^(This interface is used to retrieve and reset counter values from
6949** a [prepared statement].  The first argument is the prepared statement
6950** object to be interrogated.  The second argument
6951** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6952** to be interrogated.)^
6953** ^The current value of the requested counter is returned.
6954** ^If the resetFlg is true, then the counter is reset to zero after this
6955** interface call returns.
6957** See also: [sqlite3_status()] and [sqlite3_db_status()].
6959SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6962** CAPI3REF: Status Parameters for prepared statements
6965** These preprocessor macros define integer codes that name counter
6966** values associated with the [sqlite3_stmt_status()] interface.
6967** The meanings of the various counters are as follows:
6969** <dl>
6971** <dd>^This is the number of times that SQLite has stepped forward in
6972** a table as part of a full table scan.  Large numbers for this counter
6973** may indicate opportunities for performance improvement through
6974** careful use of indices.</dd>
6977** <dd>^This is the number of sort operations that have occurred.
6978** A non-zero value in this counter may indicate an opportunity to
6979** improvement performance through careful use of indices.</dd>
6982** <dd>^This is the number of rows inserted into transient indices that
6983** were created automatically in order to help joins run faster.
6984** A non-zero value in this counter may indicate an opportunity to
6985** improvement performance by adding permanent indices that do not
6986** need to be reinitialized each time the statement is run.</dd>
6989** <dd>^This is the number of virtual machine operations executed
6990** by the prepared statement if that number is less than or equal
6991** to 2147483647.  The number of virtual machine operations can be
6992** used as a proxy for the total work done by the prepared statement.
6993** If the number of virtual machine operations exceeds 2147483647
6994** then the value returned by this statement status code is undefined.
6995** </dd>
6996** </dl>
6999#define SQLITE_STMTSTATUS_SORT              2
7001#define SQLITE_STMTSTATUS_VM_STEP           4
7004** CAPI3REF: Custom Page Cache Object
7006** The sqlite3_pcache type is opaque.  It is implemented by
7007** the pluggable module.  The SQLite core has no knowledge of
7008** its size or internal structure and never deals with the
7009** sqlite3_pcache object except by holding and passing pointers
7010** to the object.
7012** See [sqlite3_pcache_methods2] for additional information.
7014typedef struct sqlite3_pcache sqlite3_pcache;
7017** CAPI3REF: Custom Page Cache Object
7019** The sqlite3_pcache_page object represents a single page in the
7020** page cache.  The page cache will allocate instances of this
7021** object.  Various methods of the page cache use pointers to instances
7022** of this object as parameters or as their return value.
7024** See [sqlite3_pcache_methods2] for additional information.
7026typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7027struct sqlite3_pcache_page {
7028  void *pBuf;        /* The content of the page */
7029  void *pExtra;      /* Extra information associated with the page */
7033** CAPI3REF: Application Defined Page Cache.
7034** KEYWORDS: {page cache}
7036** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7037** register an alternative page cache implementation by passing in an
7038** instance of the sqlite3_pcache_methods2 structure.)^
7039** In many applications, most of the heap memory allocated by
7040** SQLite is used for the page cache.
7041** By implementing a
7042** custom page cache using this API, an application can better control
7043** the amount of memory consumed by SQLite, the way in which
7044** that memory is allocated and released, and the policies used to
7045** determine exactly which parts of a database file are cached and for
7046** how long.
7048** The alternative page cache mechanism is an
7049** extreme measure that is only needed by the most demanding applications.
7050** The built-in page cache is recommended for most uses.
7052** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7053** internal buffer by SQLite within the call to [sqlite3_config].  Hence
7054** the application may discard the parameter after the call to
7055** [sqlite3_config()] returns.)^
7057** [[the xInit() page cache method]]
7058** ^(The xInit() method is called once for each effective
7059** call to [sqlite3_initialize()])^
7060** (usually only once during the lifetime of the process). ^(The xInit()
7061** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7062** The intent of the xInit() method is to set up global data structures
7063** required by the custom page cache implementation.
7064** ^(If the xInit() method is NULL, then the
7065** built-in default page cache is used instead of the application defined
7066** page cache.)^
7068** [[the xShutdown() page cache method]]
7069** ^The xShutdown() method is called by [sqlite3_shutdown()].
7070** It can be used to clean up
7071** any outstanding resources before process shutdown, if required.
7072** ^The xShutdown() method may be NULL.
7074** ^SQLite automatically serializes calls to the xInit method,
7075** so the xInit method need not be threadsafe.  ^The
7076** xShutdown method is only called from [sqlite3_shutdown()] so it does
7077** not need to be threadsafe either.  All other methods must be threadsafe
7078** in multithreaded applications.
7080** ^SQLite will never invoke xInit() more than once without an intervening
7081** call to xShutdown().
7083** [[the xCreate() page cache methods]]
7084** ^SQLite invokes the xCreate() method to construct a new cache instance.
7085** SQLite will typically create one cache instance for each open database file,
7086** though this is not guaranteed. ^The
7087** first parameter, szPage, is the size in bytes of the pages that must
7088** be allocated by the cache.  ^szPage will always a power of two.  ^The
7089** second parameter szExtra is a number of bytes of extra storage
7090** associated with each page cache entry.  ^The szExtra parameter will
7091** a number less than 250.  SQLite will use the
7092** extra szExtra bytes on each page to store metadata about the underlying
7093** database page on disk.  The value passed into szExtra depends
7094** on the SQLite version, the target platform, and how SQLite was compiled.
7095** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7096** created will be used to cache database pages of a file stored on disk, or
7097** false if it is used for an in-memory database. The cache implementation
7098** does not have to do anything special based with the value of bPurgeable;
7099** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
7100** never invoke xUnpin() except to deliberately delete a page.
7101** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7102** false will always have the "discard" flag set to true.
7103** ^Hence, a cache created with bPurgeable false will
7104** never contain any unpinned pages.
7106** [[the xCachesize() page cache method]]
7107** ^(The xCachesize() method may be called at any time by SQLite to set the
7108** suggested maximum cache-size (number of pages stored by) the cache
7109** instance passed as the first argument. This is the value configured using
7110** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
7111** parameter, the implementation is not required to do anything with this
7112** value; it is advisory only.
7114** [[the xPagecount() page cache methods]]
7115** The xPagecount() method must return the number of pages currently
7116** stored in the cache, both pinned and unpinned.
7118** [[the xFetch() page cache methods]]
7119** The xFetch() method locates a page in the cache and returns a pointer to
7120** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7121** The pBuf element of the returned sqlite3_pcache_page object will be a
7122** pointer to a buffer of szPage bytes used to store the content of a
7123** single database page.  The pExtra element of sqlite3_pcache_page will be
7124** a pointer to the szExtra bytes of extra storage that SQLite has requested
7125** for each entry in the page cache.
7127** The page to be fetched is determined by the key. ^The minimum key value
7128** is 1.  After it has been retrieved using xFetch, the page is considered
7129** to be "pinned".
7131** If the requested page is already in the page cache, then the page cache
7132** implementation must return a pointer to the page buffer with its content
7133** intact.  If the requested page is not already in the cache, then the
7134** cache implementation should use the value of the createFlag
7135** parameter to help it determined what action to take:
7137** <table border=1 width=85% align=center>
7138** <tr><th> createFlag <th> Behavior when page is not already in cache
7139** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
7140** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7141**                 Otherwise return NULL.
7142** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
7143**                 NULL if allocating a new page is effectively impossible.
7144** </table>
7146** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
7147** will only use a createFlag of 2 after a prior call with a createFlag of 1
7148** failed.)^  In between the to xFetch() calls, SQLite may
7149** attempt to unpin one or more cache pages by spilling the content of
7150** pinned pages to disk and synching the operating system disk cache.
7152** [[the xUnpin() page cache method]]
7153** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7154** as its second argument.  If the third parameter, discard, is non-zero,
7155** then the page must be evicted from the cache.
7156** ^If the discard parameter is
7157** zero, then the page may be discarded or retained at the discretion of
7158** page cache implementation. ^The page cache implementation
7159** may choose to evict unpinned pages at any time.
7161** The cache must not perform any reference counting. A single
7162** call to xUnpin() unpins the page regardless of the number of prior calls
7163** to xFetch().
7165** [[the xRekey() page cache methods]]
7166** The xRekey() method is used to change the key value associated with the
7167** page passed as the second argument. If the cache
7168** previously contains an entry associated with newKey, it must be
7169** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7170** to be pinned.
7172** When SQLite calls the xTruncate() method, the cache must discard all
7173** existing cache entries with page numbers (keys) greater than or equal
7174** to the value of the iLimit parameter passed to xTruncate(). If any
7175** of these pages are pinned, they are implicitly unpinned, meaning that
7176** they can be safely discarded.
7178** [[the xDestroy() page cache method]]
7179** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7180** All resources associated with the specified cache should be freed. ^After
7181** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7182** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7183** functions.
7185** [[the xShrink() page cache method]]
7186** ^SQLite invokes the xShrink() method when it wants the page cache to
7187** free up as much of heap memory as possible.  The page cache implementation
7188** is not obligated to free any memory, but well-behaved implementations should
7189** do their best.
7191typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7192struct sqlite3_pcache_methods2 {
7193  int iVersion;
7194  void *pArg;
7195  int (*xInit)(void*);
7196  void (*xShutdown)(void*);
7197  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7198  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7199  int (*xPagecount)(sqlite3_pcache*);
7200  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7201  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7202  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7203      unsigned oldKey, unsigned newKey);
7204  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7205  void (*xDestroy)(sqlite3_pcache*);
7206  void (*xShrink)(sqlite3_pcache*);
7210** This is the obsolete pcache_methods object that has now been replaced
7211** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
7212** retained in the header file for backwards compatibility only.
7214typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7215struct sqlite3_pcache_methods {
7216  void *pArg;
7217  int (*xInit)(void*);
7218  void (*xShutdown)(void*);
7219  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7220  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7221  int (*xPagecount)(sqlite3_pcache*);
7222  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7223  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7224  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7225  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7226  void (*xDestroy)(sqlite3_pcache*);
7231** CAPI3REF: Online Backup Object
7233** The sqlite3_backup object records state information about an ongoing
7234** online backup operation.  ^The sqlite3_backup object is created by
7235** a call to [sqlite3_backup_init()] and is destroyed by a call to
7236** [sqlite3_backup_finish()].
7238** See Also: [Using the SQLite Online Backup API]
7240typedef struct sqlite3_backup sqlite3_backup;
7243** CAPI3REF: Online Backup API.
7245** The backup API copies the content of one database into another.
7246** It is useful either for creating backups of databases or
7247** for copying in-memory databases to or from persistent files.
7249** See Also: [Using the SQLite Online Backup API]
7251** ^SQLite holds a write transaction open on the destination database file
7252** for the duration of the backup operation.
7253** ^The source database is read-locked only while it is being read;
7254** it is not locked continuously for the entire backup operation.
7255** ^Thus, the backup may be performed on a live source database without
7256** preventing other database connections from
7257** reading or writing to the source database while the backup is underway.
7259** ^(To perform a backup operation:
7260**   <ol>
7261**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
7262**         backup,
7263**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
7264**         the data between the two databases, and finally
7265**     <li><b>sqlite3_backup_finish()</b> is called to release all resources
7266**         associated with the backup operation.
7267**   </ol>)^
7268** There should be exactly one call to sqlite3_backup_finish() for each
7269** successful call to sqlite3_backup_init().
7271** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
7273** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
7274** [database connection] associated with the destination database
7275** and the database name, respectively.
7276** ^The database name is "main" for the main database, "temp" for the
7277** temporary database, or the name specified after the AS keyword in
7278** an [ATTACH] statement for an attached database.
7279** ^The S and M arguments passed to
7280** sqlite3_backup_init(D,N,S,M) identify the [database connection]
7281** and database name of the source database, respectively.
7282** ^The source and destination [database connections] (parameters S and D)
7283** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
7284** an error.
7286** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if
7287** there is already a read or read-write transaction open on the
7288** destination database.
7290** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
7291** returned and an error code and error message are stored in the
7292** destination [database connection] D.
7293** ^The error code and message for the failed call to sqlite3_backup_init()
7294** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
7295** [sqlite3_errmsg16()] functions.
7296** ^A successful call to sqlite3_backup_init() returns a pointer to an
7297** [sqlite3_backup] object.
7298** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
7299** sqlite3_backup_finish() functions to perform the specified backup
7300** operation.
7302** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
7304** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
7305** the source and destination databases specified by [sqlite3_backup] object B.
7306** ^If N is negative, all remaining source pages are copied.
7307** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
7308** are still more pages to be copied, then the function returns [SQLITE_OK].
7309** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
7310** from source to destination, then it returns [SQLITE_DONE].
7311** ^If an error occurs while running sqlite3_backup_step(B,N),
7312** then an [error code] is returned. ^As well as [SQLITE_OK] and
7313** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
7315** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
7317** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
7318** <ol>
7319** <li> the destination database was opened read-only, or
7320** <li> the destination database is using write-ahead-log journaling
7321** and the destination and source page sizes differ, or
7322** <li> the destination database is an in-memory database and the
7323** destination and source page sizes differ.
7324** </ol>)^
7326** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
7327** the [sqlite3_busy_handler | busy-handler function]
7328** is invoked (if one is specified). ^If the
7329** busy-handler returns non-zero before the lock is available, then
7330** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
7331** sqlite3_backup_step() can be retried later. ^If the source
7332** [database connection]
7333** is being used to write to the source database when sqlite3_backup_step()
7334** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
7335** case the call to sqlite3_backup_step() can be retried later on. ^(If
7337** [SQLITE_READONLY] is returned, then
7338** there is no point in retrying the call to sqlite3_backup_step(). These
7339** errors are considered fatal.)^  The application must accept
7340** that the backup operation has failed and pass the backup operation handle
7341** to the sqlite3_backup_finish() to release associated resources.
7343** ^The first call to sqlite3_backup_step() obtains an exclusive lock
7344** on the destination file. ^The exclusive lock is not released until either
7345** sqlite3_backup_finish() is called or the backup operation is complete
7346** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
7347** sqlite3_backup_step() obtains a [shared lock] on the source database that
7348** lasts for the duration of the sqlite3_backup_step() call.
7349** ^Because the source database is not locked between calls to
7350** sqlite3_backup_step(), the source database may be modified mid-way
7351** through the backup process.  ^If the source database is modified by an
7352** external process or via a database connection other than the one being
7353** used by the backup operation, then the backup will be automatically
7354** restarted by the next call to sqlite3_backup_step(). ^If the source
7355** database is modified by the using the same database connection as is used
7356** by the backup operation, then the backup database is automatically
7357** updated at the same time.
7359** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
7361** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
7362** application wishes to abandon the backup operation, the application
7363** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
7364** ^The sqlite3_backup_finish() interfaces releases all
7365** resources associated with the [sqlite3_backup] object.
7366** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
7367** active write-transaction on the destination database is rolled back.
7368** The [sqlite3_backup] object is invalid
7369** and may not be used following a call to sqlite3_backup_finish().
7371** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
7372** sqlite3_backup_step() errors occurred, regardless or whether or not
7373** sqlite3_backup_step() completed.
7374** ^If an out-of-memory condition or IO error occurred during any prior
7375** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
7376** sqlite3_backup_finish() returns the corresponding [error code].
7378** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
7379** is not a permanent error and does not affect the return value of
7380** sqlite3_backup_finish().
7382** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
7383** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
7385** ^The sqlite3_backup_remaining() routine returns the number of pages still
7386** to be backed up at the conclusion of the most recent sqlite3_backup_step().
7387** ^The sqlite3_backup_pagecount() routine returns the total number of pages
7388** in the source database at the conclusion of the most recent
7389** sqlite3_backup_step().
7390** ^(The values returned by these functions are only updated by
7391** sqlite3_backup_step(). If the source database is modified in a way that
7392** changes the size of the source database or the number of pages remaining,
7393** those changes are not reflected in the output of sqlite3_backup_pagecount()
7394** and sqlite3_backup_remaining() until after the next
7395** sqlite3_backup_step().)^
7397** <b>Concurrent Usage of Database Handles</b>
7399** ^The source [database connection] may be used by the application for other
7400** purposes while a backup operation is underway or being initialized.
7401** ^If SQLite is compiled and configured to support threadsafe database
7402** connections, then the source database connection may be used concurrently
7403** from within other threads.
7405** However, the application must guarantee that the destination
7406** [database connection] is not passed to any other API (by any thread) after
7407** sqlite3_backup_init() is called and before the corresponding call to
7408** sqlite3_backup_finish().  SQLite does not currently check to see
7409** if the application incorrectly accesses the destination [database connection]
7410** and so no error code is reported, but the operations may malfunction
7411** nevertheless.  Use of the destination database connection while a
7412** backup is in progress might also also cause a mutex deadlock.
7414** If running in [shared cache mode], the application must
7415** guarantee that the shared cache used by the destination database
7416** is not accessed while the backup is running. In practice this means
7417** that the application must guarantee that the disk file being
7418** backed up to is not accessed by any connection within the process,
7419** not just the specific connection that was passed to sqlite3_backup_init().
7421** The [sqlite3_backup] object itself is partially threadsafe. Multiple
7422** threads may safely make multiple concurrent calls to sqlite3_backup_step().
7423** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
7424** APIs are not strictly speaking threadsafe. If they are invoked at the
7425** same time as another thread is invoking sqlite3_backup_step() it is
7426** possible that they return invalid values.
7428SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init(
7429  sqlite3 *pDest,                        /* Destination database handle */
7430  const char *zDestName,                 /* Destination database name */
7431  sqlite3 *pSource,                      /* Source database handle */
7432  const char *zSourceName                /* Source database name */
7434SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage);
7435SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p);
7436SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p);
7437SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p);
7440** CAPI3REF: Unlock Notification
7441** METHOD: sqlite3
7443** ^When running in shared-cache mode, a database operation may fail with
7444** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7445** individual tables within the shared-cache cannot be obtained. See
7446** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7447** ^This API may be used to register a callback that SQLite will invoke
7448** when the connection currently holding the required lock relinquishes it.
7449** ^This API is only available if the library was compiled with the
7450** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7452** See Also: [Using the SQLite Unlock Notification Feature].
7454** ^Shared-cache locks are released when a database connection concludes
7455** its current transaction, either by committing it or rolling it back.
7457** ^When a connection (known as the blocked connection) fails to obtain a
7458** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7459** identity of the database connection (the blocking connection) that
7460** has locked the required resource is stored internally. ^After an
7461** application receives an SQLITE_LOCKED error, it may call the
7462** sqlite3_unlock_notify() method with the blocked connection handle as
7463** the first argument to register for a callback that will be invoked
7464** when the blocking connections current transaction is concluded. ^The
7465** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7466** call that concludes the blocking connections transaction.
7468** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7469** there is a chance that the blocking connection will have already
7470** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7471** If this happens, then the specified callback is invoked immediately,
7472** from within the call to sqlite3_unlock_notify().)^
7474** ^If the blocked connection is attempting to obtain a write-lock on a
7475** shared-cache table, and more than one other connection currently holds
7476** a read-lock on the same table, then SQLite arbitrarily selects one of
7477** the other connections to use as the blocking connection.
7479** ^(There may be at most one unlock-notify callback registered by a
7480** blocked connection. If sqlite3_unlock_notify() is called when the
7481** blocked connection already has a registered unlock-notify callback,
7482** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7483** called with a NULL pointer as its second argument, then any existing
7484** unlock-notify callback is canceled. ^The blocked connections
7485** unlock-notify callback may also be canceled by closing the blocked
7486** connection using [sqlite3_close()].
7488** The unlock-notify callback is not reentrant. If an application invokes
7489** any sqlite3_xxx API functions from within an unlock-notify callback, a
7490** crash or deadlock may be the result.
7492** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7493** returns SQLITE_OK.
7495** <b>Callback Invocation Details</b>
7497** When an unlock-notify callback is registered, the application provides a
7498** single void* pointer that is passed to the callback when it is invoked.
7499** However, the signature of the callback function allows SQLite to pass
7500** it an array of void* context pointers. The first argument passed to
7501** an unlock-notify callback is a pointer to an array of void* pointers,
7502** and the second is the number of entries in the array.
7504** When a blocking connections transaction is concluded, there may be
7505** more than one blocked connection that has registered for an unlock-notify
7506** callback. ^If two or more such blocked connections have specified the
7507** same callback function, then instead of invoking the callback function
7508** multiple times, it is invoked once with the set of void* context pointers
7509** specified by the blocked connections bundled together into an array.
7510** This gives the application an opportunity to prioritize any actions
7511** related to the set of unblocked database connections.
7513** <b>Deadlock Detection</b>
7515** Assuming that after registering for an unlock-notify callback a
7516** database waits for the callback to be issued before taking any further
7517** action (a reasonable assumption), then using this API may cause the
7518** application to deadlock. For example, if connection X is waiting for
7519** connection Y's transaction to be concluded, and similarly connection
7520** Y is waiting on connection X's transaction, then neither connection
7521** will proceed and the system may remain deadlocked indefinitely.
7523** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7524** detection. ^If a given call to sqlite3_unlock_notify() would put the
7525** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7526** unlock-notify callback is registered. The system is said to be in
7527** a deadlocked state if connection A has registered for an unlock-notify
7528** callback on the conclusion of connection B's transaction, and connection
7529** B has itself registered for an unlock-notify callback when connection
7530** A's transaction is concluded. ^Indirect deadlock is also detected, so
7531** the system is also considered to be deadlocked if connection B has
7532** registered for an unlock-notify callback on the conclusion of connection
7533** C's transaction, where connection C is waiting on connection A. ^Any
7534** number of levels of indirection are allowed.
7536** <b>The "DROP TABLE" Exception</b>
7538** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7539** always appropriate to call sqlite3_unlock_notify(). There is however,
7540** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7541** SQLite checks if there are any currently executing SELECT statements
7542** that belong to the same connection. If there are, SQLITE_LOCKED is
7543** returned. In this case there is no "blocking connection", so invoking
7544** sqlite3_unlock_notify() results in the unlock-notify callback being
7545** invoked immediately. If the application then re-attempts the "DROP TABLE"
7546** or "DROP INDEX" query, an infinite loop might be the result.
7548** One way around this problem is to check the extended error code returned
7549** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7550** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7551** the special "DROP TABLE/INDEX" case, the extended error code is just
7554SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
7555  sqlite3 *pBlocked,                          /* Waiting connection */
7556  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
7557  void *pNotifyArg                            /* Argument to pass to xNotify */
7562** CAPI3REF: String Comparison
7564** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7565** and extensions to compare the contents of two buffers containing UTF-8
7566** strings in a case-independent fashion, using the same definition of "case
7567** independence" that SQLite uses internally when comparing identifiers.
7569SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *);
7570SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int);
7573** CAPI3REF: String Globbing
7575** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
7576** the glob pattern P, and it returns non-zero if string X does not match
7577** the glob pattern P.  ^The definition of glob pattern matching used in
7578** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7579** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
7580** sensitive.
7582** Note that this routine returns zero on a match and non-zero if the strings
7583** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7585SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr);
7588** CAPI3REF: Error Logging Interface
7590** ^The [sqlite3_log()] interface writes a message into the [error log]
7591** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7592** ^If logging is enabled, the zFormat string and subsequent arguments are
7593** used with [sqlite3_snprintf()] to generate the final output string.
7595** The sqlite3_log() interface is intended for use by extensions such as
7596** virtual tables, collating functions, and SQL functions.  While there is
7597** nothing to prevent an application from calling sqlite3_log(), doing so
7598** is considered bad form.
7600** The zFormat string must not be NULL.
7602** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7603** will not use dynamically allocated memory.  The log message is stored in
7604** a fixed-length buffer on the stack.  If the log message is longer than
7605** a few hundred characters, it will be truncated to the length of the
7606** buffer.
7608SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...);
7611** CAPI3REF: Write-Ahead Log Commit Hook
7612** METHOD: sqlite3
7614** ^The [sqlite3_wal_hook()] function is used to register a callback that
7615** is invoked each time data is committed to a database in wal mode.
7617** ^(The callback is invoked by SQLite after the commit has taken place and
7618** the associated write-lock on the database released)^, so the implementation
7619** may read, write or [checkpoint] the database as required.
7621** ^The first parameter passed to the callback function when it is invoked
7622** is a copy of the third parameter passed to sqlite3_wal_hook() when
7623** registering the callback. ^The second is a copy of the database handle.
7624** ^The third parameter is the name of the database that was written to -
7625** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7626** is the number of pages currently in the write-ahead log file,
7627** including those that were just committed.
7629** The callback function should normally return [SQLITE_OK].  ^If an error
7630** code is returned, that error will propagate back up through the
7631** SQLite code base to cause the statement that provoked the callback
7632** to report an error, though the commit will have still occurred. If the
7633** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7634** that does not correspond to any valid SQLite error code, the results
7635** are undefined.
7637** A single database handle may have at most a single write-ahead log callback
7638** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7639** previously registered write-ahead log callback. ^Note that the
7640** [sqlite3_wal_autocheckpoint()] interface and the
7641** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7642** those overwrite any prior [sqlite3_wal_hook()] settings.
7644SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
7645  sqlite3*,
7646  int(*)(void *,sqlite3*,const char*,int),
7647  void*
7651** CAPI3REF: Configure an auto-checkpoint
7652** METHOD: sqlite3
7654** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7655** [sqlite3_wal_hook()] that causes any database on [database connection] D
7656** to automatically [checkpoint]
7657** after committing a transaction if there are N or
7658** more frames in the [write-ahead log] file.  ^Passing zero or
7659** a negative value as the nFrame parameter disables automatic
7660** checkpoints entirely.
7662** ^The callback registered by this function replaces any existing callback
7663** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
7664** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7665** configured by this function.
7667** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7668** from SQL.
7670** ^Checkpoints initiated by this mechanism are
7671** [sqlite3_wal_checkpoint_v2|PASSIVE].
7673** ^Every new [database connection] defaults to having the auto-checkpoint
7674** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7675** pages.  The use of this interface
7676** is only necessary if the default setting is found to be suboptimal
7677** for a particular application.
7679SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7682** CAPI3REF: Checkpoint a database
7683** METHOD: sqlite3
7685** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
7686** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
7688** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
7689** [write-ahead log] for database X on [database connection] D to be
7690** transferred into the database file and for the write-ahead log to
7691** be reset.  See the [checkpointing] documentation for addition
7692** information.
7694** This interface used to be the only way to cause a checkpoint to
7695** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
7696** interface was added.  This interface is retained for backwards
7697** compatibility and as a convenience for applications that need to manually
7698** start a callback but which do not need the full power (and corresponding
7699** complication) of [sqlite3_wal_checkpoint_v2()].
7701SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7704** CAPI3REF: Checkpoint a database
7705** METHOD: sqlite3
7707** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
7708** operation on database X of [database connection] D in mode M.  Status
7709** information is written back into integers pointed to by L and C.)^
7710** ^(The M parameter must be a valid [checkpoint mode]:)^
7712** <dl>
7714**   ^Checkpoint as many frames as possible without waiting for any database
7715**   readers or writers to finish, then sync the database file if all frames
7716**   in the log were checkpointed. ^The [busy-handler callback]
7717**   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
7718**   ^On the other hand, passive mode might leave the checkpoint unfinished
7719**   if there are concurrent readers or writers.
7722**   ^This mode blocks (it invokes the
7723**   [sqlite3_busy_handler|busy-handler callback]) until there is no
7724**   database writer and all readers are reading from the most recent database
7725**   snapshot. ^It then checkpoints all frames in the log file and syncs the
7726**   database file. ^This mode blocks new database writers while it is pending,
7727**   but new database readers are allowed to continue unimpeded.
7730**   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
7731**   that after checkpointing the log file it blocks (calls the
7732**   [busy-handler callback])
7733**   until all readers are reading from the database file only. ^This ensures
7734**   that the next writer will restart the log file from the beginning.
7735**   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
7736**   database writer attempts while it is pending, but does not impede readers.
7739**   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
7740**   addition that it also truncates the log file to zero bytes just prior
7741**   to a successful return.
7742** </dl>
7744** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
7745** the log file or to -1 if the checkpoint could not run because
7746** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
7747** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
7748** log file (including any that were already checkpointed before the function
7749** was called) or to -1 if the checkpoint could not run due to an error or
7750** because the database is not in WAL mode. ^Note that upon successful
7751** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
7752** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
7754** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
7755** any other process is running a checkpoint operation at the same time, the
7756** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
7757** busy-handler configured, it will not be invoked in this case.
7759** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
7760** exclusive "writer" lock on the database file. ^If the writer lock cannot be
7761** obtained immediately, and a busy-handler is configured, it is invoked and
7762** the writer lock retried until either the busy-handler returns 0 or the lock
7763** is successfully obtained. ^The busy-handler is also invoked while waiting for
7764** database readers as described above. ^If the busy-handler returns 0 before
7765** the writer lock is obtained or while waiting for database readers, the
7766** checkpoint operation proceeds from that point in the same way as
7767** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7768** without blocking any further. ^SQLITE_BUSY is returned in this case.
7770** ^If parameter zDb is NULL or points to a zero length string, then the
7771** specified operation is attempted on all WAL databases [attached] to
7772** [database connection] db.  In this case the
7773** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
7774** an SQLITE_BUSY error is encountered when processing one or more of the
7775** attached WAL databases, the operation is still attempted on any remaining
7776** attached databases and SQLITE_BUSY is returned at the end. ^If any other
7777** error occurs while processing an attached database, processing is abandoned
7778** and the error code is returned to the caller immediately. ^If no error
7779** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7780** databases, SQLITE_OK is returned.
7782** ^If database zDb is the name of an attached database that is not in WAL
7783** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
7784** zDb is not NULL (or a zero length string) and is not the name of any
7785** attached database, SQLITE_ERROR is returned to the caller.
7787** ^Unless it returns SQLITE_MISUSE,
7788** the sqlite3_wal_checkpoint_v2() interface
7789** sets the error information that is queried by
7790** [sqlite3_errcode()] and [sqlite3_errmsg()].
7792** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
7793** from SQL.
7795SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
7796  sqlite3 *db,                    /* Database handle */
7797  const char *zDb,                /* Name of attached database (or NULL) */
7798  int eMode,                      /* SQLITE_CHECKPOINT_* value */
7799  int *pnLog,                     /* OUT: Size of WAL log in frames */
7800  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
7804** CAPI3REF: Checkpoint Mode Values
7805** KEYWORDS: {checkpoint mode}
7807** These constants define all valid values for the "checkpoint mode" passed
7808** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
7809** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
7810** meaning of each of these checkpoint modes.
7812#define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
7813#define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
7814#define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */
7815#define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */
7818** CAPI3REF: Virtual Table Interface Configuration
7820** This function may be called by either the [xConnect] or [xCreate] method
7821** of a [virtual table] implementation to configure
7822** various facets of the virtual table interface.
7824** If this interface is invoked outside the context of an xConnect or
7825** xCreate virtual table method then the behavior is undefined.
7827** At present, there is only one option that may be configured using
7828** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
7829** may be added in the future.
7831SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...);
7834** CAPI3REF: Virtual Table Configuration Options
7836** These macros define the various options to the
7837** [sqlite3_vtab_config()] interface that [virtual table] implementations
7838** can use to customize and optimize their behavior.
7840** <dl>
7842** <dd>Calls of the form
7843** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7844** where X is an integer.  If X is zero, then the [virtual table] whose
7845** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7846** support constraints.  In this configuration (which is the default) if
7847** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7848** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7849** specified as part of the users SQL statement, regardless of the actual
7850** ON CONFLICT mode specified.
7852** If X is non-zero, then the virtual table implementation guarantees
7853** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7854** any modifications to internal or persistent data structures have been made.
7855** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7856** is able to roll back a statement or database transaction, and abandon
7857** or continue processing the current SQL statement as appropriate.
7858** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7859** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7860** had been ABORT.
7862** Virtual table implementations that are required to handle OR REPLACE
7863** must do so within the [xUpdate] method. If a call to the
7864** [sqlite3_vtab_on_conflict()] function indicates that the current ON
7865** CONFLICT policy is REPLACE, the virtual table implementation should
7866** silently replace the appropriate rows within the xUpdate callback and
7867** return SQLITE_OK. Or, if this is not possible, it may return
7868** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
7869** constraint handling.
7870** </dl>
7875** CAPI3REF: Determine The Virtual Table Conflict Policy
7877** This function may only be called from within a call to the [xUpdate] method
7878** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7879** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7880** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7881** of the SQL statement that triggered the call to the [xUpdate] method of the
7882** [virtual table].
7884SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *);
7887** CAPI3REF: Conflict resolution modes
7888** KEYWORDS: {conflict resolution mode}
7890** These constants are returned by [sqlite3_vtab_on_conflict()] to
7891** inform a [virtual table] implementation what the [ON CONFLICT] mode
7892** is for the SQL statement being evaluated.
7894** Note that the [SQLITE_IGNORE] constant is also used as a potential
7895** return value from the [sqlite3_set_authorizer()] callback and that
7896** [SQLITE_ABORT] is also a [result code].
7898#define SQLITE_ROLLBACK 1
7899/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7900#define SQLITE_FAIL     3
7901/* #define SQLITE_ABORT 4  // Also an error code */
7902#define SQLITE_REPLACE  5
7905** CAPI3REF: Prepared Statement Scan Status Opcodes
7906** KEYWORDS: {scanstatus options}
7908** The following constants can be used for the T parameter to the
7909** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
7910** different metric for sqlite3_stmt_scanstatus() to return.
7912** When the value returned to V is a string, space to hold that string is
7913** managed by the prepared statement S and will be automatically freed when
7914** S is finalized.
7916** <dl>
7918** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
7919** set to the total number of times that the X-th loop has run.</dd>
7922** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
7923** to the total number of rows examined by all iterations of the X-th loop.</dd>
7926** <dd>^The "double" variable pointed to by the T parameter will be set to the
7927** query planner's estimate for the average number of rows output from each
7928** iteration of the X-th loop.  If the query planner's estimates was accurate,
7929** then this value will approximate the quotient NVISIT/NLOOP and the
7930** product of this value for all prior loops with the same SELECTID will
7931** be the NLOOP value for the current loop.
7934** <dd>^The "const char *" variable pointed to by the T parameter will be set
7935** to a zero-terminated UTF-8 string containing the name of the index or table
7936** used for the X-th loop.
7939** <dd>^The "const char *" variable pointed to by the T parameter will be set
7940** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
7941** description for the X-th loop.
7944** <dd>^The "int" variable pointed to by the T parameter will be set to the
7945** "select-id" for the X-th loop.  The select-id identifies which query or
7946** subquery the loop is part of.  The main query has a select-id of zero.
7947** The select-id is the same value as is output in the first column
7948** of an [EXPLAIN QUERY PLAN] query.
7949** </dl>
7951#define SQLITE_SCANSTAT_NLOOP    0
7953#define SQLITE_SCANSTAT_EST      2
7954#define SQLITE_SCANSTAT_NAME     3
7959** CAPI3REF: Prepared Statement Scan Status
7960** METHOD: sqlite3_stmt
7962** This interface returns information about the predicted and measured
7963** performance for pStmt.  Advanced applications can use this
7964** interface to compare the predicted and the measured performance and
7965** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
7967** Since this interface is expected to be rarely used, it is only
7968** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
7969** compile-time option.
7971** The "iScanStatusOp" parameter determines which status information to return.
7972** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
7973** of this interface is undefined.
7974** ^The requested measurement is written into a variable pointed to by
7975** the "pOut" parameter.
7976** Parameter "idx" identifies the specific loop to retrieve statistics for.
7977** Loops are numbered starting from zero. ^If idx is out of range - less than
7978** zero or greater than or equal to the total number of loops used to implement
7979** the statement - a non-zero value is returned and the variable that pOut
7980** points to is unchanged.
7982** ^Statistics might not be available for all loops in all statements. ^In cases
7983** where there exist loops with no available statistics, this function behaves
7984** as if the loop did not exist - it returns non-zero and leave the variable
7985** that pOut points to unchanged.
7987** See also: [sqlite3_stmt_scanstatus_reset()]
7989SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus(
7990  sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
7991  int idx,                  /* Index of loop to report on */
7992  int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
7993  void *pOut                /* Result written here */
7997** CAPI3REF: Zero Scan-Status Counters
7998** METHOD: sqlite3_stmt
8000** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8002** This API is only available if the library is built with pre-processor
8003** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8005SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8009** Undo the hack that converts floating point types to integer for
8010** builds on processors without floating point support.
8013# undef double
8016#if 0
8017}  /* End of the 'extern "C"' block */
8019#endif /* _SQLITE3_H_ */
8022** 2010 August 30
8024** The author disclaims copyright to this source code.  In place of
8025** a legal notice, here is a blessing:
8027**    May you do good and not evil.
8028**    May you find forgiveness for yourself and forgive others.
8029**    May you share freely, never taking more than you give.
8034#ifndef _SQLITE3RTREE_H_
8035#define _SQLITE3RTREE_H_
8038#if 0
8039extern "C" {
8042typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
8043typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
8045/* The double-precision datatype used by RTree depends on the
8046** SQLITE_RTREE_INT_ONLY compile-time option.
8049  typedef sqlite3_int64 sqlite3_rtree_dbl;
8051  typedef double sqlite3_rtree_dbl;
8055** Register a geometry callback named zGeom that can be used as part of an
8056** R-Tree geometry query as follows:
8058**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
8060SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback(
8061  sqlite3 *db,
8062  const char *zGeom,
8063  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
8064  void *pContext
8069** A pointer to a structure of the following type is passed as the first
8070** argument to callbacks registered using rtree_geometry_callback().
8072struct sqlite3_rtree_geometry {
8073  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
8074  int nParam;                     /* Size of array aParam[] */
8075  sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
8076  void *pUser;                    /* Callback implementation user data */
8077  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
8081** Register a 2nd-generation geometry callback named zScore that can be
8082** used as part of an R-Tree geometry query as follows:
8084**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
8086SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback(
8087  sqlite3 *db,
8088  const char *zQueryFunc,
8089  int (*xQueryFunc)(sqlite3_rtree_query_info*),
8090  void *pContext,
8091  void (*xDestructor)(void*)
8096** A pointer to a structure of the following type is passed as the
8097** argument to scored geometry callback registered using
8098** sqlite3_rtree_query_callback().
8100** Note that the first 5 fields of this structure are identical to
8101** sqlite3_rtree_geometry.  This structure is a subclass of
8102** sqlite3_rtree_geometry.
8104struct sqlite3_rtree_query_info {
8105  void *pContext;                   /* pContext from when function registered */
8106  int nParam;                       /* Number of function parameters */
8107  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
8108  void *pUser;                      /* callback can use this, if desired */
8109  void (*xDelUser)(void*);          /* function to free pUser */
8110  sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
8111  unsigned int *anQueue;            /* Number of pending entries in the queue */
8112  int nCoord;                       /* Number of coordinates */
8113  int iLevel;                       /* Level of current node or entry */
8114  int mxLevel;                      /* The largest iLevel value in the tree */
8115  sqlite3_int64 iRowid;             /* Rowid for current entry */
8116  sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
8117  int eParentWithin;                /* Visibility of parent node */
8118  int eWithin;                      /* OUT: Visiblity */
8119  sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
8120  /* The following fields are only available in 3.8.11 and later */
8121  sqlite3_value **apSqlParam;       /* Original SQL values of parameters */
8125** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
8127#define NOT_WITHIN       0   /* Object completely outside of query region */
8128#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
8129#define FULLY_WITHIN     2   /* Object fully contained within query region */
8132#if 0
8133}  /* end of the 'extern "C"' block */
8136#endif  /* ifndef _SQLITE3RTREE_H_ */
8139** 2014 May 31
8141** The author disclaims copyright to this source code.  In place of
8142** a legal notice, here is a blessing:
8144**    May you do good and not evil.
8145**    May you find forgiveness for yourself and forgive others.
8146**    May you share freely, never taking more than you give.
8150** Interfaces to extend FTS5. Using the interfaces defined in this file,
8151** FTS5 may be extended with:
8153**     * custom tokenizers, and
8154**     * custom auxiliary functions.
8158#ifndef _FTS5_H
8159#define _FTS5_H
8162#if 0
8163extern "C" {
8169** Virtual table implementations may overload SQL functions by implementing
8170** the sqlite3_module.xFindFunction() method.
8173typedef struct Fts5ExtensionApi Fts5ExtensionApi;
8174typedef struct Fts5Context Fts5Context;
8175typedef struct Fts5PhraseIter Fts5PhraseIter;
8177typedef void (*fts5_extension_function)(
8178  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
8179  Fts5Context *pFts,              /* First arg to pass to pApi functions */
8180  sqlite3_context *pCtx,          /* Context for returning result/error */
8181  int nVal,                       /* Number of values in apVal[] array */
8182  sqlite3_value **apVal           /* Array of trailing arguments */
8185struct Fts5PhraseIter {
8186  const unsigned char *a;
8187  const unsigned char *b;
8193** xUserData(pFts):
8194**   Return a copy of the context pointer the extension function was
8195**   registered with.
8197** xColumnTotalSize(pFts, iCol, pnToken):
8198**   If parameter iCol is less than zero, set output variable *pnToken
8199**   to the total number of tokens in the FTS5 table. Or, if iCol is
8200**   non-negative but less than the number of columns in the table, return
8201**   the total number of tokens in column iCol, considering all rows in
8202**   the FTS5 table.
8204**   If parameter iCol is greater than or equal to the number of columns
8205**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
8206**   an OOM condition or IO error), an appropriate SQLite error code is
8207**   returned.
8209** xColumnCount(pFts):
8210**   Return the number of columns in the table.
8212** xColumnSize(pFts, iCol, pnToken):
8213**   If parameter iCol is less than zero, set output variable *pnToken
8214**   to the total number of tokens in the current row. Or, if iCol is
8215**   non-negative but less than the number of columns in the table, set
8216**   *pnToken to the number of tokens in column iCol of the current row.
8218**   If parameter iCol is greater than or equal to the number of columns
8219**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
8220**   an OOM condition or IO error), an appropriate SQLite error code is
8221**   returned.
8223** xColumnText:
8224**   This function attempts to retrieve the text of column iCol of the
8225**   current document. If successful, (*pz) is set to point to a buffer
8226**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
8227**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
8228**   if an error occurs, an SQLite error code is returned and the final values
8229**   of (*pz) and (*pn) are undefined.
8231** xPhraseCount:
8232**   Returns the number of phrases in the current query expression.
8234** xPhraseSize:
8235**   Returns the number of tokens in phrase iPhrase of the query. Phrases
8236**   are numbered starting from zero.
8238** xInstCount:
8239**   Set *pnInst to the total number of occurrences of all phrases within
8240**   the query within the current row. Return SQLITE_OK if successful, or
8241**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
8243** xInst:
8244**   Query for the details of phrase match iIdx within the current row.
8245**   Phrase matches are numbered starting from zero, so the iIdx argument
8246**   should be greater than or equal to zero and smaller than the value
8247**   output by xInstCount().
8249**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
8250**   if an error occurs.
8252** xRowid:
8253**   Returns the rowid of the current row.
8255** xTokenize:
8256**   Tokenize text using the tokenizer belonging to the FTS5 table.
8258** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
8259**   This API function is used to query the FTS table for phrase iPhrase
8260**   of the current query. Specifically, a query equivalent to:
8262**       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
8264**   with $p set to a phrase equivalent to the phrase iPhrase of the
8265**   current query is executed. For each row visited, the callback function
8266**   passed as the fourth argument is invoked. The context and API objects
8267**   passed to the callback function may be used to access the properties of
8268**   each matched row. Invoking Api.xUserData() returns a copy of the pointer
8269**   passed as the third argument to pUserData.
8271**   If the callback function returns any value other than SQLITE_OK, the
8272**   query is abandoned and the xQueryPhrase function returns immediately.
8273**   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
8274**   Otherwise, the error code is propagated upwards.
8276**   If the query runs to completion without incident, SQLITE_OK is returned.
8277**   Or, if some error occurs before the query completes or is aborted by
8278**   the callback, an SQLite error code is returned.
8281** xSetAuxdata(pFts5, pAux, xDelete)
8283**   Save the pointer passed as the second argument as the extension functions
8284**   "auxiliary data". The pointer may then be retrieved by the current or any
8285**   future invocation of the same fts5 extension function made as part of
8286**   of the same MATCH query using the xGetAuxdata() API.
8288**   Each extension function is allocated a single auxiliary data slot for
8289**   each FTS query (MATCH expression). If the extension function is invoked
8290**   more than once for a single FTS query, then all invocations share a
8291**   single auxiliary data context.
8293**   If there is already an auxiliary data pointer when this function is
8294**   invoked, then it is replaced by the new pointer. If an xDelete callback
8295**   was specified along with the original pointer, it is invoked at this
8296**   point.
8298**   The xDelete callback, if one is specified, is also invoked on the
8299**   auxiliary data pointer after the FTS5 query has finished.
8301**   If an error (e.g. an OOM condition) occurs within this function, an
8302**   the auxiliary data is set to NULL and an error code returned. If the
8303**   xDelete parameter was not NULL, it is invoked on the auxiliary data
8304**   pointer before returning.
8307** xGetAuxdata(pFts5, bClear)
8309**   Returns the current auxiliary data pointer for the fts5 extension
8310**   function. See the xSetAuxdata() method for details.
8312**   If the bClear argument is non-zero, then the auxiliary data is cleared
8313**   (set to NULL) before this function returns. In this case the xDelete,
8314**   if any, is not invoked.
8317** xRowCount(pFts5, pnRow)
8319**   This function is used to retrieve the total number of rows in the table.
8320**   In other words, the same value that would be returned by:
8322**        SELECT count(*) FROM ftstable;
8324** xPhraseFirst()
8325**   This function is used, along with type Fts5PhraseIter and the xPhraseNext
8326**   method, to iterate through all instances of a single query phrase within
8327**   the current row. This is the same information as is accessible via the
8328**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
8329**   to use, this API may be faster under some circumstances. To iterate
8330**   through instances of phrase iPhrase, use the following code:
8332**       Fts5PhraseIter iter;
8333**       int iCol, iOff;
8334**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
8335**           iOff>=0;
8336**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
8337**       ){
8338**         // An instance of phrase iPhrase at offset iOff of column iCol
8339**       }
8341**   The Fts5PhraseIter structure is defined above. Applications should not
8342**   modify this structure directly - it should only be used as shown above
8343**   with the xPhraseFirst() and xPhraseNext() API methods.
8345** xPhraseNext()
8346**   See xPhraseFirst above.
8348struct Fts5ExtensionApi {
8349  int iVersion;                   /* Currently always set to 1 */
8351  void *(*xUserData)(Fts5Context*);
8353  int (*xColumnCount)(Fts5Context*);
8354  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
8355  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
8357  int (*xTokenize)(Fts5Context*,
8358    const char *pText, int nText, /* Text to tokenize */
8359    void *pCtx,                   /* Context passed to xToken() */
8360    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
8361  );
8363  int (*xPhraseCount)(Fts5Context*);
8364  int (*xPhraseSize)(Fts5Context*, int iPhrase);
8366  int (*xInstCount)(Fts5Context*, int *pnInst);
8367  int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
8369  sqlite3_int64 (*xRowid)(Fts5Context*);
8370  int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
8371  int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
8373  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
8374    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
8375  );
8376  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
8377  void *(*xGetAuxdata)(Fts5Context*, int bClear);
8379  void (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
8380  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
8390** Applications may also register custom tokenizer types. A tokenizer
8391** is registered by providing fts5 with a populated instance of the
8392** following structure. All structure methods must be defined, setting
8393** any member of the fts5_tokenizer struct to NULL leads to undefined
8394** behaviour. The structure methods are expected to function as follows:
8396** xCreate:
8397**   This function is used to allocate and inititalize a tokenizer instance.
8398**   A tokenizer instance is required to actually tokenize text.
8400**   The first argument passed to this function is a copy of the (void*)
8401**   pointer provided by the application when the fts5_tokenizer object
8402**   was registered with FTS5 (the third argument to xCreateTokenizer()).
8403**   The second and third arguments are an array of nul-terminated strings
8404**   containing the tokenizer arguments, if any, specified following the
8405**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
8406**   to create the FTS5 table.
8408**   The final argument is an output variable. If successful, (*ppOut)
8409**   should be set to point to the new tokenizer handle and SQLITE_OK
8410**   returned. If an error occurs, some value other than SQLITE_OK should
8411**   be returned. In this case, fts5 assumes that the final value of *ppOut
8412**   is undefined.
8414** xDelete:
8415**   This function is invoked to delete a tokenizer handle previously
8416**   allocated using xCreate(). Fts5 guarantees that this function will
8417**   be invoked exactly once for each successful call to xCreate().
8419** xTokenize:
8420**   This function is expected to tokenize the nText byte string indicated
8421**   by argument pText. pText may or may not be nul-terminated. The first
8422**   argument passed to this function is a pointer to an Fts5Tokenizer object
8423**   returned by an earlier call to xCreate().
8425**   The second argument indicates the reason that FTS5 is requesting
8426**   tokenization of the supplied text. This is always one of the following
8427**   four values:
8429**   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
8430**            or removed from the FTS table. The tokenizer is being invoked to
8431**            determine the set of tokens to add to (or delete from) the
8432**            FTS index.
8434**       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
8435**            against the FTS index. The tokenizer is being called to tokenize
8436**            a bareword or quoted string specified as part of the query.
8438**       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
8439**            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
8440**            followed by a "*" character, indicating that the last token
8441**            returned by the tokenizer will be treated as a token prefix.
8443**       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
8444**            satisfy an fts5_api.xTokenize() request made by an auxiliary
8445**            function. Or an fts5_api.xColumnSize() request made by the same
8446**            on a columnsize=0 database.
8447**   </ul>
8449**   For each token in the input string, the supplied callback xToken() must
8450**   be invoked. The first argument to it should be a copy of the pointer
8451**   passed as the second argument to xTokenize(). The third and fourth
8452**   arguments are a pointer to a buffer containing the token text, and the
8453**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
8454**   of the first byte of and first byte immediately following the text from
8455**   which the token is derived within the input.
8457**   The second argument passed to the xToken() callback ("tflags") should
8458**   normally be set to 0. The exception is if the tokenizer supports
8459**   synonyms. In this case see the discussion below for details.
8461**   FTS5 assumes the xToken() callback is invoked for each token in the
8462**   order that they occur within the input text.
8464**   If an xToken() callback returns any value other than SQLITE_OK, then
8465**   the tokenization should be abandoned and the xTokenize() method should
8466**   immediately return a copy of the xToken() return value. Or, if the
8467**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
8468**   if an error occurs with the xTokenize() implementation itself, it
8469**   may abandon the tokenization and return any error code other than
8474**   Custom tokenizers may also support synonyms. Consider a case in which a
8475**   user wishes to query for a phrase such as "first place". Using the
8476**   built-in tokenizers, the FTS5 query 'first + place' will match instances
8477**   of "first place" within the document set, but not alternative forms
8478**   such as "1st place". In some applications, it would be better to match
8479**   all instances of "first place" or "1st place" regardless of which form
8480**   the user specified in the MATCH query text.
8482**   There are several ways to approach this in FTS5:
8484**   <ol><li> By mapping all synonyms to a single token. In this case, the
8485**            In the above example, this means that the tokenizer returns the
8486**            same token for inputs "first" and "1st". Say that token is in
8487**            fact "first", so that when the user inserts the document "I won
8488**            1st place" entries are added to the index for tokens "i", "won",
8489**            "first" and "place". If the user then queries for '1st + place',
8490**            the tokenizer substitutes "first" for "1st" and the query works
8491**            as expected.
8493**       <li> By adding multiple synonyms for a single term to the FTS index.
8494**            In this case, when tokenizing query text, the tokenizer may
8495**            provide multiple synonyms for a single term within the document.
8496**            FTS5 then queries the index for each synonym individually. For
8497**            example, faced with the query:
8499**   <codeblock>
8500**     ... MATCH 'first place'</codeblock>
8502**            the tokenizer offers both "1st" and "first" as synonyms for the
8503**            first token in the MATCH query and FTS5 effectively runs a query
8504**            similar to:
8506**   <codeblock>
8507**     ... MATCH '(first OR 1st) place'</codeblock>
8509**            except that, for the purposes of auxiliary functions, the query
8510**            still appears to contain just two phrases - "(first OR 1st)"
8511**            being treated as a single phrase.
8513**       <li> By adding multiple synonyms for a single term to the FTS index.
8514**            Using this method, when tokenizing document text, the tokenizer
8515**            provides multiple synonyms for each token. So that when a
8516**            document such as "I won first place" is tokenized, entries are
8517**            added to the FTS index for "i", "won", "first", "1st" and
8518**            "place".
8520**            This way, even if the tokenizer does not provide synonyms
8521**            when tokenizing query text (it should not - to do would be
8522**            inefficient), it doesn't matter if the user queries for
8523**            'first + place' or '1st + place', as there are entires in the
8524**            FTS index corresponding to both forms of the first token.
8525**   </ol>
8527**   Whether it is parsing document or query text, any call to xToken that
8528**   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
8529**   is considered to supply a synonym for the previous token. For example,
8530**   when parsing the document "I won first place", a tokenizer that supports
8531**   synonyms would call xToken() 5 times, as follows:
8533**   <codeblock>
8534**       xToken(pCtx, 0, "i",                      1,  0,  1);
8535**       xToken(pCtx, 0, "won",                    3,  2,  5);
8536**       xToken(pCtx, 0, "first",                  5,  6, 11);
8537**       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
8538**       xToken(pCtx, 0, "place",                  5, 12, 17);
8541**   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
8542**   xToken() is called. Multiple synonyms may be specified for a single token
8543**   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
8544**   There is no limit to the number of synonyms that may be provided for a
8545**   single token.
8547**   In many cases, method (1) above is the best approach. It does not add
8548**   extra data to the FTS index or require FTS5 to query for multiple terms,
8549**   so it is efficient in terms of disk space and query speed. However, it
8550**   does not support prefix queries very well. If, as suggested above, the
8551**   token "first" is subsituted for "1st" by the tokenizer, then the query:
8553**   <codeblock>
8554**     ... MATCH '1s*'</codeblock>
8556**   will not match documents that contain the token "1st" (as the tokenizer
8557**   will probably not map "1s" to any prefix of "first").
8559**   For full prefix support, method (3) may be preferred. In this case,
8560**   because the index contains entries for both "first" and "1st", prefix
8561**   queries such as 'fi*' or '1s*' will match correctly. However, because
8562**   extra entries are added to the FTS index, this method uses more space
8563**   within the database.
8565**   Method (2) offers a midpoint between (1) and (3). Using this method,
8566**   a query such as '1s*' will match documents that contain the literal
8567**   token "1st", but not "first" (assuming the tokenizer is not able to
8568**   provide synonyms for prefixes). However, a non-prefix query like '1st'
8569**   will match against "1st" and "first". This method does not require
8570**   extra disk space, as no extra entries are added to the FTS index.
8571**   On the other hand, it may require more CPU cycles to run MATCH queries,
8572**   as separate queries of the FTS index are required for each synonym.
8574**   When using methods (2) or (3), it is important that the tokenizer only
8575**   provide synonyms when tokenizing document text (method (2)) or query
8576**   text (method (3)), not both. Doing so will not cause any errors, but is
8577**   inefficient.
8579typedef struct Fts5Tokenizer Fts5Tokenizer;
8580typedef struct fts5_tokenizer fts5_tokenizer;
8581struct fts5_tokenizer {
8582  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
8583  void (*xDelete)(Fts5Tokenizer*);
8584  int (*xTokenize)(Fts5Tokenizer*,
8585      void *pCtx,
8586      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
8587      const char *pText, int nText,
8588      int (*xToken)(
8589        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
8590        int tflags,         /* Mask of FTS5_TOKEN_* flags */
8591        const char *pToken, /* Pointer to buffer containing token */
8592        int nToken,         /* Size of token in bytes */
8593        int iStart,         /* Byte offset of token within input text */
8594        int iEnd            /* Byte offset of end of token within input text */
8595      )
8596  );
8599/* Flags that may be passed as the third argument to xTokenize() */
8600#define FTS5_TOKENIZE_QUERY     0x0001
8601#define FTS5_TOKENIZE_PREFIX    0x0002
8602#define FTS5_TOKENIZE_DOCUMENT  0x0004
8603#define FTS5_TOKENIZE_AUX       0x0008
8605/* Flags that may be passed by the tokenizer implementation back to FTS5
8606** as the third argument to the supplied xToken callback. */
8607#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
8616typedef struct fts5_api fts5_api;
8617struct fts5_api {
8618  int iVersion;                   /* Currently always set to 2 */
8620  /* Create a new tokenizer */
8621  int (*xCreateTokenizer)(
8622    fts5_api *pApi,
8623    const char *zName,
8624    void *pContext,
8625    fts5_tokenizer *pTokenizer,
8626    void (*xDestroy)(void*)
8627  );
8629  /* Find an existing tokenizer */
8630  int (*xFindTokenizer)(
8631    fts5_api *pApi,
8632    const char *zName,
8633    void **ppContext,
8634    fts5_tokenizer *pTokenizer
8635  );
8637  /* Create a new auxiliary function */
8638  int (*xCreateFunction)(
8639    fts5_api *pApi,
8640    const char *zName,
8641    void *pContext,
8642    fts5_extension_function xFunction,
8643    void (*xDestroy)(void*)
8644  );
8651#if 0
8652}  /* end of the 'extern "C"' block */
8655#endif /* _FTS5_H */
8659/************** End of sqlite3.h *********************************************/
8660/************** Continuing where we left off in sqliteInt.h ******************/
8663** Include the configuration header output by 'configure' if we're using the
8664** autoconf-based build
8667#include "config.h"
8670/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
8671/************** Begin file sqliteLimit.h *************************************/
8673** 2007 May 7
8675** The author disclaims copyright to this source code.  In place of
8676** a legal notice, here is a blessing:
8678**    May you do good and not evil.
8679**    May you find forgiveness for yourself and forgive others.
8680**    May you share freely, never taking more than you give.
8684** This file defines various limits of what SQLite can process.
8688** The maximum length of a TEXT or BLOB in bytes.   This also
8689** limits the size of a row in a table or index.
8691** The hard limit is the ability of a 32-bit signed integer
8692** to count the size: 2^31-1 or 2147483647.
8695# define SQLITE_MAX_LENGTH 1000000000
8699** This is the maximum number of
8701**    * Columns in a table
8702**    * Columns in an index
8703**    * Columns in a view
8704**    * Terms in the SET clause of an UPDATE statement
8705**    * Terms in the result set of a SELECT statement
8706**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
8707**    * Terms in the VALUES clause of an INSERT statement
8709** The hard upper limit here is 32676.  Most database people will
8710** tell you that in a well-normalized database, you usually should
8711** not have more than a dozen or so columns in any table.  And if
8712** that is the case, there is no point in having more than a few
8713** dozen values in any of the other situations described above.
8716# define SQLITE_MAX_COLUMN 2000
8720** The maximum length of a single SQL statement in bytes.
8722** It used to be the case that setting this value to zero would
8723** turn the limit off.  That is no longer true.  It is not possible
8724** to turn this limit off.
8727# define SQLITE_MAX_SQL_LENGTH 1000000000
8731** The maximum depth of an expression tree. This is limited to
8732** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might
8733** want to place more severe limits on the complexity of an
8734** expression.
8736** A value of 0 used to mean that the limit was not enforced.
8737** But that is no longer true.  The limit is now strictly enforced
8738** at all times.
8741# define SQLITE_MAX_EXPR_DEPTH 1000
8745** The maximum number of terms in a compound SELECT statement.
8746** The code generator for compound SELECT statements does one
8747** level of recursion for each term.  A stack overflow can result
8748** if the number of terms is too large.  In practice, most SQL
8749** never has more than 3 or 4 terms.  Use a value of 0 to disable
8750** any limit on the number of terms in a compount SELECT.
8757** The maximum number of opcodes in a VDBE program.
8758** Not currently enforced.
8760#ifndef SQLITE_MAX_VDBE_OP
8761# define SQLITE_MAX_VDBE_OP 25000
8765** The maximum number of arguments to an SQL function.
8768# define SQLITE_MAX_FUNCTION_ARG 127
8772** The suggested maximum number of in-memory pages to use for
8773** the main database table and for temporary tables.
8775** IMPLEMENTATION-OF: R-31093-59126 The default suggested cache size
8776** is 2000 pages.
8777** IMPLEMENTATION-OF: R-48205-43578 The default suggested cache size can be
8778** altered using the SQLITE_DEFAULT_CACHE_SIZE compile-time options.
8781# define SQLITE_DEFAULT_CACHE_SIZE  2000
8785** The default number of frames to accumulate in the log file before
8786** checkpointing the database in WAL mode.
8793** The maximum number of attached databases.  This must be between 0
8794** and 62.  The upper bound on 62 is because a 64-bit integer bitmap
8795** is used internally to track attached databases.
8798# define SQLITE_MAX_ATTACHED 10
8803** The maximum value of a ?nnn wildcard that the parser will accept.
8809/* Maximum page size.  The upper bound on this value is 65536.  This a limit
8810** imposed by the use of 16-bit offsets within each page.
8812** Earlier versions of SQLite allowed the user to change this value at
8813** compile time. This is no longer permitted, on the grounds that it creates
8814** a library that is technically incompatible with an SQLite library
8815** compiled with a different limit. If a process operating on a database
8816** with a page-size of 65536 bytes crashes, then an instance of SQLite
8817** compiled with the default page-size limit will not be able to rollback
8818** the aborted transaction. This could lead to database corruption.
8823#define SQLITE_MAX_PAGE_SIZE 65536
8827** The default size of a database page.
8830# define SQLITE_DEFAULT_PAGE_SIZE 1024
8838** Ordinarily, if no value is explicitly provided, SQLite creates databases
8839** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
8840** device characteristics (sector-size and atomic write() support),
8841** SQLite may choose a larger value. This constant is the maximum value
8842** SQLite will choose on its own.
8854** Maximum number of pages in one database file.
8856** This is really just the default value for the max_page_count pragma.
8857** This value can be lowered (or raised) at run-time using that the
8858** max_page_count macro.
8861# define SQLITE_MAX_PAGE_COUNT 1073741823
8865** Maximum length (in bytes) of the pattern in a LIKE or GLOB
8866** operator.
8873** Maximum depth of recursion for triggers.
8875** A value of 1 means that a trigger program will not be able to itself
8876** fire any triggers. A value of 0 means that no trigger programs at all
8877** may be executed.
8880# define SQLITE_MAX_TRIGGER_DEPTH 1000
8883/************** End of sqliteLimit.h *****************************************/
8884/************** Continuing where we left off in sqliteInt.h ******************/
8886/* Disable nuisance warnings on Borland compilers */
8887#if defined(__BORLANDC__)
8888#pragma warn -rch /* unreachable code */
8889#pragma warn -ccc /* Condition is always true or false */
8890#pragma warn -aus /* Assigned value is never used */
8891#pragma warn -csu /* Comparing signed and unsigned */
8892#pragma warn -spa /* Suspicious pointer arithmetic */
8896** Include standard header files as necessary
8898#ifdef HAVE_STDINT_H
8899#include <stdint.h>
8901#ifdef HAVE_INTTYPES_H
8902#include <inttypes.h>
8906** The following macros are used to cast pointers to integers and
8907** integers to pointers.  The way you do this varies from one compiler
8908** to the next, so we have developed the following set of #if statements
8909** to generate appropriate macros for a wide range of compilers.
8911** The correct "ANSI" way to do this is to use the intptr_t type.
8912** Unfortunately, that typedef is not available on all compilers, or
8913** if it is available, it requires an #include of specific headers
8914** that vary from one machine to the next.
8916** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
8917** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
8918** So we have to define the macros in different ways depending on the
8919** compiler.
8921#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
8922# define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
8923# define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
8924#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
8925# define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
8926# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
8927#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
8928# define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
8929# define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
8930#else                          /* Generates a warning - but it always works */
8931# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
8932# define SQLITE_PTR_TO_INT(X)  ((int)(X))
8936** A macro to hint to the compiler that a function should not be
8937** inlined.
8939#if defined(__GNUC__)
8940#  define SQLITE_NOINLINE  __attribute__((noinline))
8941#elif defined(_MSC_VER) && _MSC_VER>=1310
8942#  define SQLITE_NOINLINE  __declspec(noinline)
8944#  define SQLITE_NOINLINE
8948** Make sure that the compiler intrinsics we desire are enabled when
8949** compiling with an appropriate version of MSVC unless prevented by
8953#  if defined(_MSC_VER) && _MSC_VER>=1300
8954#    if !defined(_WIN32_WCE)
8955#      include <intrin.h>
8956#      pragma intrinsic(_byteswap_ushort)
8957#      pragma intrinsic(_byteswap_ulong)
8958#      pragma intrinsic(_ReadWriteBarrier)
8959#    else
8960#      include <cmnintrin.h>
8961#    endif
8962#  endif
8966** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
8967** 0 means mutexes are permanently disable and the library is never
8968** threadsafe.  1 means the library is serialized which is the highest
8969** level of threadsafety.  2 means the library is multithreaded - multiple
8970** threads can use SQLite as long as no two threads try to use the same
8971** database connection at the same time.
8973** Older versions of SQLite used an optional THREADSAFE macro.
8974** We support that for legacy.
8976#if !defined(SQLITE_THREADSAFE)
8977# if defined(THREADSAFE)
8979# else
8980#   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
8981# endif
8985** Powersafe overwrite is on by default.  But can be turned off using
8986** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
8993** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by
8994** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in
8995** which case memory allocation statistics are disabled by default.
9002** Exactly one of the following macros must be defined in order to
9003** specify which memory allocation subsystem to use.
9005**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
9006**     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
9007**     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails
9008**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
9010** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
9011** assert() macro is enabled, each call into the Win32 native heap subsystem
9012** will cause HeapValidate to be called.  If heap validation should fail, an
9013** assertion will be triggered.
9015** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
9016** the default.
9018#if defined(SQLITE_SYSTEM_MALLOC) \
9019  + defined(SQLITE_WIN32_MALLOC) \
9020  + defined(SQLITE_ZERO_MALLOC) \
9021  + defined(SQLITE_MEMDEBUG)>1
9022# error "Two or more of the following compile-time configuration options\
9023 are defined but at most one is allowed:\
9027#if defined(SQLITE_SYSTEM_MALLOC) \
9028  + defined(SQLITE_WIN32_MALLOC) \
9029  + defined(SQLITE_ZERO_MALLOC) \
9030  + defined(SQLITE_MEMDEBUG)==0
9035** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
9036** sizes of memory allocations below this value where possible.
9038#if !defined(SQLITE_MALLOC_SOFT_LIMIT)
9039# define SQLITE_MALLOC_SOFT_LIMIT 1024
9043** We need to define _XOPEN_SOURCE as follows in order to enable
9044** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
9045** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
9046** it.
9048#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
9049#  define _XOPEN_SOURCE 600
9053** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
9054** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
9055** make it true by defining or undefining NDEBUG.
9057** Setting NDEBUG makes the code smaller and faster by disabling the
9058** assert() statements in the code.  So we want the default action
9059** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
9060** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
9061** feature.
9063#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
9064# define NDEBUG 1
9066#if defined(NDEBUG) && defined(SQLITE_DEBUG)
9067# undef NDEBUG
9078** The testcase() macro is used to aid in coverage testing.  When
9079** doing coverage testing, the condition inside the argument to
9080** testcase() must be evaluated both true and false in order to
9081** get full branch coverage.  The testcase() macro is inserted
9082** to help ensure adequate test coverage in places where simple
9083** condition/decision coverage is inadequate.  For example, testcase()
9084** can be used to make sure boundary values are tested.  For
9085** bitmask tests, testcase() can be used to make sure each bit
9086** is significant and used at least once.  On switch statements
9087** where multiple cases go to the same block of code, testcase()
9088** can insure that all cases are evaluated.
9092SQLITE_PRIVATE   void sqlite3Coverage(int);
9093# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
9095# define testcase(X)
9099** The TESTONLY macro is used to enclose variable declarations or
9100** other bits of code that are needed to support the arguments
9101** within testcase() and assert() macros.
9103#if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
9104# define TESTONLY(X)  X
9106# define TESTONLY(X)
9110** Sometimes we need a small amount of code such as a variable initialization
9111** to setup for a later assert() statement.  We do not want this code to
9112** appear when assert() is disabled.  The following macro is therefore
9113** used to contain that setup code.  The "VVA" acronym stands for
9114** "Verification, Validation, and Accreditation".  In other words, the
9115** code within VVA_ONLY() will only run during verification processes.
9117#ifndef NDEBUG
9118# define VVA_ONLY(X)  X
9120# define VVA_ONLY(X)
9124** The ALWAYS and NEVER macros surround boolean expressions which
9125** are intended to always be true or false, respectively.  Such
9126** expressions could be omitted from the code completely.  But they
9127** are included in a few cases in order to enhance the resilience
9128** of SQLite to unexpected behavior - to make the code "self-healing"
9129** or "ductile" rather than being "brittle" and crashing at the first
9130** hint of unplanned behavior.
9132** In other words, ALWAYS and NEVER are added for defensive code.
9134** When doing coverage testing ALWAYS and NEVER are hard-coded to
9135** be true and false so that the unreachable code they specify will
9136** not be counted as untested code.
9138#if defined(SQLITE_COVERAGE_TEST)
9139# define ALWAYS(X)      (1)
9140# define NEVER(X)       (0)
9141#elif !defined(NDEBUG)
9142# define ALWAYS(X)      ((X)?1:(assert(0),0))
9143# define NEVER(X)       ((X)?(assert(0),1):0)
9145# define ALWAYS(X)      (X)
9146# define NEVER(X)       (X)
9150** Declarations used for tracing the operating system interfaces.
9152#if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \
9153    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
9154  extern int sqlite3OSTrace;
9155# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
9158# define OSTRACE(X)
9163** Is the sqlite3ErrName() function needed in the build?  Currently,
9164** it is needed by "mutex_w32.c" (when debugging), "os_win.c" (when
9165** OSTRACE is enabled), and by several "test*.c" files (which are
9166** compiled using SQLITE_TEST).
9168#if defined(SQLITE_HAVE_OS_TRACE) || defined(SQLITE_TEST) || \
9169    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
9176** Return true (non-zero) if the input is an integer that is too large
9177** to fit in 32-bits.  This macro is used inside of various testcase()
9178** macros to verify that we have tested SQLite for large-file support.
9180#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
9183** The macro unlikely() is a hint that surrounds a boolean
9184** expression that is usually false.  Macro likely() surrounds
9185** a boolean expression that is usually true.  These hints could,
9186** in theory, be used by the compiler to generate better code, but
9187** currently they are just comments for human readers.
9189#define likely(X)    (X)
9190#define unlikely(X)  (X)
9192/************** Include hash.h in the middle of sqliteInt.h ******************/
9193/************** Begin file hash.h ********************************************/
9195** 2001 September 22
9197** The author disclaims copyright to this source code.  In place of
9198** a legal notice, here is a blessing:
9200**    May you do good and not evil.
9201**    May you find forgiveness for yourself and forgive others.
9202**    May you share freely, never taking more than you give.
9205** This is the header file for the generic hash-table implementation
9206** used in SQLite.
9208#ifndef _SQLITE_HASH_H_
9209#define _SQLITE_HASH_H_
9211/* Forward declarations of structures. */
9212typedef struct Hash Hash;
9213typedef struct HashElem HashElem;
9215/* A complete hash table is an instance of the following structure.
9216** The internals of this structure are intended to be opaque -- client
9217** code should not attempt to access or modify the fields of this structure
9218** directly.  Change this structure only by using the routines below.
9219** However, some of the "procedures" and "functions" for modifying and
9220** accessing this structure are really macros, so we can't really make
9221** this structure opaque.
9223** All elements of the hash table are on a single doubly-linked list.
9224** Hash.first points to the head of this list.
9226** There are Hash.htsize buckets.  Each bucket points to a spot in
9227** the global doubly-linked list.  The contents of the bucket are the
9228** element pointed to plus the next _ht.count-1 elements in the list.
9230** Hash.htsize and Hash.ht may be zero.  In that case lookup is done
9231** by a linear search of the global list.  For small tables, the
9232** Hash.ht table is never allocated because if there are few elements
9233** in the table, it is faster to do a linear search than to manage
9234** the hash table.
9236struct Hash {
9237  unsigned int htsize;      /* Number of buckets in the hash table */
9238  unsigned int count;       /* Number of entries in this table */
9239  HashElem *first;          /* The first element of the array */
9240  struct _ht {              /* the hash table */
9241    int count;                 /* Number of entries with this hash */
9242    HashElem *chain;           /* Pointer to first entry with this hash */
9243  } *ht;
9246/* Each element in the hash table is an instance of the following
9247** structure.  All elements are stored on a single doubly-linked list.
9249** Again, this structure is intended to be opaque, but it can't really
9250** be opaque because it is used by macros.
9252struct HashElem {
9253  HashElem *next, *prev;       /* Next and previous elements in the table */
9254  void *data;                  /* Data associated with this element */
9255  const char *pKey;            /* Key associated with this element */
9259** Access routines.  To delete, insert a NULL pointer.
9261SQLITE_PRIVATE void sqlite3HashInit(Hash*);
9262SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, void *pData);
9263SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey);
9264SQLITE_PRIVATE void sqlite3HashClear(Hash*);
9267** Macros for looping over all elements of a hash table.  The idiom is
9268** like this:
9270**   Hash h;
9271**   HashElem *p;
9272**   ...
9273**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
9274**     SomeStructure *pData = sqliteHashData(p);
9275**     // do something with pData
9276**   }
9278#define sqliteHashFirst(H)  ((H)->first)
9279#define sqliteHashNext(E)   ((E)->next)
9280#define sqliteHashData(E)   ((E)->data)
9281/* #define sqliteHashKey(E)    ((E)->pKey) // NOT USED */
9282/* #define sqliteHashKeysize(E) ((E)->nKey)  // NOT USED */
9285** Number of entries in a hash table
9287/* #define sqliteHashCount(H)  ((H)->count) // NOT USED */
9289#endif /* _SQLITE_HASH_H_ */
9291/************** End of hash.h ************************************************/
9292/************** Continuing where we left off in sqliteInt.h ******************/
9293/************** Include parse.h in the middle of sqliteInt.h *****************/
9294/************** Begin file parse.h *******************************************/
9295#define TK_SEMI                             1
9296#define TK_EXPLAIN                          2
9297#define TK_QUERY                            3
9298#define TK_PLAN                             4
9299#define TK_BEGIN                            5
9300#define TK_TRANSACTION                      6
9301#define TK_DEFERRED                         7
9302#define TK_IMMEDIATE                        8
9303#define TK_EXCLUSIVE                        9
9304#define TK_COMMIT                          10
9305#define TK_END                             11
9306#define TK_ROLLBACK                        12
9307#define TK_SAVEPOINT                       13
9308#define TK_RELEASE                         14
9309#define TK_TO                              15
9310#define TK_TABLE                           16
9311#define TK_CREATE                          17
9312#define TK_IF                              18
9313#define TK_NOT                             19
9314#define TK_EXISTS                          20
9315#define TK_TEMP                            21
9316#define TK_LP                              22
9317#define TK_RP                              23
9318#define TK_AS                              24
9319#define TK_WITHOUT                         25
9320#define TK_COMMA                           26
9321#define TK_ID                              27
9322#define TK_INDEXED                         28
9323#define TK_ABORT                           29
9324#define TK_ACTION                          30
9325#define TK_AFTER                           31
9326#define TK_ANALYZE                         32
9327#define TK_ASC                             33
9328#define TK_ATTACH                          34
9329#define TK_BEFORE                          35
9330#define TK_BY                              36
9331#define TK_CASCADE                         37
9332#define TK_CAST                            38
9333#define TK_COLUMNKW                        39
9334#define TK_CONFLICT                        40
9335#define TK_DATABASE                        41
9336#define TK_DESC                            42
9337#define TK_DETACH                          43
9338#define TK_EACH                            44
9339#define TK_FAIL                            45
9340#define TK_FOR                             46
9341#define TK_IGNORE                          47
9342#define TK_INITIALLY                       48
9343#define TK_INSTEAD                         49
9344#define TK_LIKE_KW                         50
9345#define TK_MATCH                           51
9346#define TK_NO                              52
9347#define TK_KEY                             53
9348#define TK_OF                              54
9349#define TK_OFFSET                          55
9350#define TK_PRAGMA                          56
9351#define TK_RAISE                           57
9352#define TK_RECURSIVE                       58
9353#define TK_REPLACE                         59
9354#define TK_RESTRICT                        60
9355#define TK_ROW                             61
9356#define TK_TRIGGER                         62
9357#define TK_VACUUM                          63
9358#define TK_VIEW                            64
9359#define TK_VIRTUAL                         65
9360#define TK_WITH                            66
9361#define TK_REINDEX                         67
9362#define TK_RENAME                          68
9363#define TK_CTIME_KW                        69
9364#define TK_ANY                             70
9365#define TK_OR                              71
9366#define TK_AND                             72
9367#define TK_IS                              73
9368#define TK_BETWEEN                         74
9369#define TK_IN                              75
9370#define TK_ISNULL                          76
9371#define TK_NOTNULL                         77
9372#define TK_NE                              78
9373#define TK_EQ                              79
9374#define TK_GT                              80
9375#define TK_LE                              81
9376#define TK_LT                              82
9377#define TK_GE                              83
9378#define TK_ESCAPE                          84
9379#define TK_BITAND                          85
9380#define TK_BITOR                           86
9381#define TK_LSHIFT                          87
9382#define TK_RSHIFT                          88
9383#define TK_PLUS                            89
9384#define TK_MINUS                           90
9385#define TK_STAR                            91
9386#define TK_SLASH                           92
9387#define TK_REM                             93
9388#define TK_CONCAT                          94
9389#define TK_COLLATE                         95
9390#define TK_BITNOT                          96
9391#define TK_STRING                          97
9392#define TK_JOIN_KW                         98
9393#define TK_CONSTRAINT                      99
9394#define TK_DEFAULT                        100
9395#define TK_NULL                           101
9396#define TK_PRIMARY                        102
9397#define TK_UNIQUE                         103
9398#define TK_CHECK                          104
9399#define TK_REFERENCES                     105
9400#define TK_AUTOINCR                       106
9401#define TK_ON                             107
9402#define TK_INSERT                         108
9403#define TK_DELETE                         109
9404#define TK_UPDATE                         110
9405#define TK_SET                            111
9406#define TK_DEFERRABLE                     112
9407#define TK_FOREIGN                        113
9408#define TK_DROP                           114
9409#define TK_UNION                          115
9410#define TK_ALL                            116
9411#define TK_EXCEPT                         117
9412#define TK_INTERSECT                      118
9413#define TK_SELECT                         119
9414#define TK_VALUES                         120
9415#define TK_DISTINCT                       121
9416#define TK_DOT                            122
9417#define TK_FROM                           123
9418#define TK_JOIN                           124
9419#define TK_USING                          125
9420#define TK_ORDER                          126
9421#define TK_GROUP                          127
9422#define TK_HAVING                         128
9423#define TK_LIMIT                          129
9424#define TK_WHERE                          130
9425#define TK_INTO                           131
9426#define TK_INTEGER                        132
9427#define TK_FLOAT                          133
9428#define TK_BLOB                           134
9429#define TK_VARIABLE                       135
9430#define TK_CASE                           136
9431#define TK_WHEN                           137
9432#define TK_THEN                           138
9433#define TK_ELSE                           139
9434#define TK_INDEX                          140
9435#define TK_ALTER                          141
9436#define TK_ADD                            142
9437#define TK_TO_TEXT                        143
9438#define TK_TO_BLOB                        144
9439#define TK_TO_NUMERIC                     145
9440#define TK_TO_INT                         146
9441#define TK_TO_REAL                        147
9442#define TK_ISNOT                          148
9443#define TK_END_OF_FILE                    149
9444#define TK_ILLEGAL                        150
9445#define TK_SPACE                          151
9446#define TK_UNCLOSED_STRING                152
9447#define TK_FUNCTION                       153
9448#define TK_COLUMN                         154
9449#define TK_AGG_FUNCTION                   155
9450#define TK_AGG_COLUMN                     156
9451#define TK_UMINUS                         157
9452#define TK_UPLUS                          158
9453#define TK_REGISTER                       159
9455/************** End of parse.h ***********************************************/
9456/************** Continuing where we left off in sqliteInt.h ******************/
9457#include <stdio.h>
9458#include <stdlib.h>
9459#include <string.h>
9460#include <assert.h>
9461#include <stddef.h>
9464** If compiling for a processor that lacks floating point support,
9465** substitute integer for floating-point
9468# define double sqlite_int64
9469# define float sqlite_int64
9470# define LONGDOUBLE_TYPE sqlite_int64
9471# ifndef SQLITE_BIG_DBL
9472#   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
9473# endif
9475# define SQLITE_OMIT_TRACE 1
9479#ifndef SQLITE_BIG_DBL
9480# define SQLITE_BIG_DBL (1e99)
9484** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
9485** afterward. Having this macro allows us to cause the C compiler
9486** to omit code used by TEMP tables without messy #ifndef statements.
9489#define OMIT_TEMPDB 1
9491#define OMIT_TEMPDB 0
9495** The "file format" number is an integer that is incremented whenever
9496** the VDBE-level file format changes.  The following macros define the
9497** the default file format for new databases and the maximum file format
9498** that the library can read.
9506** Determine whether triggers are recursive by default.  This can be
9507** changed at run-time using a pragma.
9514** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
9515** on the command-line
9518# define SQLITE_TEMP_STORE 1
9519# define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
9523** If no value has been provided for SQLITE_MAX_WORKER_THREADS, or if
9524** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it
9525** to zero.
9543** The default initial allocation for the pagecache when using separate
9544** pagecaches for each database connection.  A positive number is the
9545** number of pages.  A negative number N translations means that a buffer
9546** of -1024*N bytes is allocated and used for as many pages as it will hold.
9554** GCC does not define the offsetof() macro so we'll have to do it
9555** ourselves.
9557#ifndef offsetof
9558#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
9562** Macros to compute minimum and maximum of two numbers.
9564#define MIN(A,B) ((A)<(B)?(A):(B))
9565#define MAX(A,B) ((A)>(B)?(A):(B))
9568** Swap two objects of type TYPE.
9570#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
9573** Check to see if this machine uses EBCDIC.  (Yes, believe it or
9574** not, there are still machines out there that use EBCDIC.)
9576#if 'A' == '\301'
9577# define SQLITE_EBCDIC 1
9579# define SQLITE_ASCII 1
9583** Integers of known sizes.  These typedefs might change for architectures
9584** where the sizes very.  Preprocessor macros are available so that the
9585** types can be conveniently redefined at compile-type.  Like this:
9587**         cc '-DUINTPTR_TYPE=long long int' ...
9589#ifndef UINT32_TYPE
9590# ifdef HAVE_UINT32_T
9591#  define UINT32_TYPE uint32_t
9592# else
9593#  define UINT32_TYPE unsigned int
9594# endif
9596#ifndef UINT16_TYPE
9597# ifdef HAVE_UINT16_T
9598#  define UINT16_TYPE uint16_t
9599# else
9600#  define UINT16_TYPE unsigned short int
9601# endif
9603#ifndef INT16_TYPE
9604# ifdef HAVE_INT16_T
9605#  define INT16_TYPE int16_t
9606# else
9607#  define INT16_TYPE short int
9608# endif
9610#ifndef UINT8_TYPE
9611# ifdef HAVE_UINT8_T
9612#  define UINT8_TYPE uint8_t
9613# else
9614#  define UINT8_TYPE unsigned char
9615# endif
9617#ifndef INT8_TYPE
9618# ifdef HAVE_INT8_T
9619#  define INT8_TYPE int8_t
9620# else
9621#  define INT8_TYPE signed char
9622# endif
9625# define LONGDOUBLE_TYPE long double
9627typedef sqlite_int64 i64;          /* 8-byte signed integer */
9628typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
9629typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
9630typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
9631typedef INT16_TYPE i16;            /* 2-byte signed integer */
9632typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
9633typedef INT8_TYPE i8;              /* 1-byte signed integer */
9636** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
9637** that can be stored in a u32 without loss of data.  The value
9638** is 0x00000000ffffffff.  But because of quirks of some compilers, we
9639** have to specify the value in the less intuitive manner shown:
9641#define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
9644** The datatype used to store estimates of the number of rows in a
9645** table or index.  This is an unsigned integer type.  For 99.9% of
9646** the world, a 32-bit integer is sufficient.  But a 64-bit integer
9647** can be used at compile-time if desired.
9649#ifdef SQLITE_64BIT_STATS
9650 typedef u64