1#if defined(_MSC_VER) && _MSC_VER < 1300
2#pragma optimize("", off)
3#endif
4
5/******************************************************************************
6** This file is an amalgamation of many separate C source files from SQLite
7** version 3.7.7.1.  By combining all the individual C code files into this
8** single large file, the entire code can be compiled as a single translation
9** unit.  This allows many compilers to do optimizations that would not be
10** possible if the files were compiled separately.  Performance improvements
11** of 5% or more are commonly seen when SQLite is compiled as a single
12** translation unit.
13**
14** This file is all you need to compile SQLite.  To use SQLite in other
15** programs, you need this file and the "sqlite3.h" header file that defines
16** the programming interface to the SQLite library.  (If you do not have
17** the "sqlite3.h" header file at hand, you will find a copy embedded within
18** the text of this file.  Search for "Begin file sqlite3.h" to find the start
19** of the embedded sqlite3.h header file.) Additional code files may be needed
20** if you want a wrapper to interface SQLite with your choice of programming
21** language. The code for the "sqlite3" command-line shell is also in a
22** separate file. This file contains only code for the core SQLite library.
23*/
24#define SQLITE_CORE 1
25#define SQLITE_AMALGAMATION 1
26#ifndef SQLITE_PRIVATE
27# define SQLITE_PRIVATE static
28#endif
29#ifndef SQLITE_API
30# define SQLITE_API
31#endif
32/************** Begin file sqliteInt.h ***************************************/
33/*
34** 2001 September 15
35**
36** The author disclaims copyright to this source code.  In place of
37** a legal notice, here is a blessing:
38**
39**    May you do good and not evil.
40**    May you find forgiveness for yourself and forgive others.
41**    May you share freely, never taking more than you give.
42**
43*************************************************************************
44** Internal interface definitions for SQLite.
45**
46*/
47#ifndef _SQLITEINT_H_
48#define _SQLITEINT_H_
49
50/*
51** These #defines should enable >2GB file support on POSIX if the
52** underlying operating system supports it.  If the OS lacks
53** large file support, or if the OS is windows, these should be no-ops.
54**
55** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
56** system #includes.  Hence, this block of code must be the very first
57** code in all source files.
58**
59** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
60** on the compiler command line.  This is necessary if you are compiling
61** on a recent machine (ex: Red Hat 7.2) but you want your code to work
62** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
63** without this option, LFS is enable.  But LFS does not exist in the kernel
64** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
65** portability you should omit LFS.
66**
67** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
68*/
69#ifndef SQLITE_DISABLE_LFS
70# define _LARGE_FILE       1
71# ifndef _FILE_OFFSET_BITS
72#   define _FILE_OFFSET_BITS 64
73# endif
74# define _LARGEFILE_SOURCE 1
75#endif
76
77/*
78** Include the configuration header output by 'configure' if we're using the
79** autoconf-based build
80*/
81#ifdef _HAVE_SQLITE_CONFIG_H
82#include "config.h"
83#endif
84
85/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
86/************** Begin file sqliteLimit.h *************************************/
87/*
88** 2007 May 7
89**
90** The author disclaims copyright to this source code.  In place of
91** a legal notice, here is a blessing:
92**
93**    May you do good and not evil.
94**    May you find forgiveness for yourself and forgive others.
95**    May you share freely, never taking more than you give.
96**
97*************************************************************************
98**
99** This file defines various limits of what SQLite can process.
100*/
101
102/*
103** The maximum length of a TEXT or BLOB in bytes.   This also
104** limits the size of a row in a table or index.
105**
106** The hard limit is the ability of a 32-bit signed integer
107** to count the size: 2^31-1 or 2147483647.
108*/
109#ifndef SQLITE_MAX_LENGTH
110# define SQLITE_MAX_LENGTH 1000000000
111#endif
112
113/*
114** This is the maximum number of
115**
116**    * Columns in a table
117**    * Columns in an index
118**    * Columns in a view
119**    * Terms in the SET clause of an UPDATE statement
120**    * Terms in the result set of a SELECT statement
121**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
122**    * Terms in the VALUES clause of an INSERT statement
123**
124** The hard upper limit here is 32676.  Most database people will
125** tell you that in a well-normalized database, you usually should
126** not have more than a dozen or so columns in any table.  And if
127** that is the case, there is no point in having more than a few
128** dozen values in any of the other situations described above.
129*/
130#ifndef SQLITE_MAX_COLUMN
131# define SQLITE_MAX_COLUMN 2000
132#endif
133
134/*
135** The maximum length of a single SQL statement in bytes.
136**
137** It used to be the case that setting this value to zero would
138** turn the limit off.  That is no longer true.  It is not possible
139** to turn this limit off.
140*/
141#ifndef SQLITE_MAX_SQL_LENGTH
142# define SQLITE_MAX_SQL_LENGTH 1000000000
143#endif
144
145/*
146** The maximum depth of an expression tree. This is limited to
147** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might
148** want to place more severe limits on the complexity of an
149** expression.
150**
151** A value of 0 used to mean that the limit was not enforced.
152** But that is no longer true.  The limit is now strictly enforced
153** at all times.
154*/
155#ifndef SQLITE_MAX_EXPR_DEPTH
156# define SQLITE_MAX_EXPR_DEPTH 1000
157#endif
158
159/*
160** The maximum number of terms in a compound SELECT statement.
161** The code generator for compound SELECT statements does one
162** level of recursion for each term.  A stack overflow can result
163** if the number of terms is too large.  In practice, most SQL
164** never has more than 3 or 4 terms.  Use a value of 0 to disable
165** any limit on the number of terms in a compount SELECT.
166*/
167#ifndef SQLITE_MAX_COMPOUND_SELECT
168# define SQLITE_MAX_COMPOUND_SELECT 500
169#endif
170
171/*
172** The maximum number of opcodes in a VDBE program.
173** Not currently enforced.
174*/
175#ifndef SQLITE_MAX_VDBE_OP
176# define SQLITE_MAX_VDBE_OP 25000
177#endif
178
179/*
180** The maximum number of arguments to an SQL function.
181*/
182#ifndef SQLITE_MAX_FUNCTION_ARG
183# define SQLITE_MAX_FUNCTION_ARG 127
184#endif
185
186/*
187** The maximum number of in-memory pages to use for the main database
188** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
189*/
190#ifndef SQLITE_DEFAULT_CACHE_SIZE
191# define SQLITE_DEFAULT_CACHE_SIZE  2000
192#endif
193#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
194# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
195#endif
196
197/*
198** The default number of frames to accumulate in the log file before
199** checkpointing the database in WAL mode.
200*/
201#ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT
202# define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT  1000
203#endif
204
205/*
206** The maximum number of attached databases.  This must be between 0
207** and 62.  The upper bound on 62 is because a 64-bit integer bitmap
208** is used internally to track attached databases.
209*/
210#ifndef SQLITE_MAX_ATTACHED
211# define SQLITE_MAX_ATTACHED 10
212#endif
213
214
215/*
216** The maximum value of a ?nnn wildcard that the parser will accept.
217*/
218#ifndef SQLITE_MAX_VARIABLE_NUMBER
219# define SQLITE_MAX_VARIABLE_NUMBER 999
220#endif
221
222/* Maximum page size.  The upper bound on this value is 65536.  This a limit
223** imposed by the use of 16-bit offsets within each page.
224**
225** Earlier versions of SQLite allowed the user to change this value at
226** compile time. This is no longer permitted, on the grounds that it creates
227** a library that is technically incompatible with an SQLite library
228** compiled with a different limit. If a process operating on a database
229** with a page-size of 65536 bytes crashes, then an instance of SQLite
230** compiled with the default page-size limit will not be able to rollback
231** the aborted transaction. This could lead to database corruption.
232*/
233#ifdef SQLITE_MAX_PAGE_SIZE
234# undef SQLITE_MAX_PAGE_SIZE
235#endif
236#define SQLITE_MAX_PAGE_SIZE 65536
237
238
239/*
240** The default size of a database page.
241*/
242#ifndef SQLITE_DEFAULT_PAGE_SIZE
243# define SQLITE_DEFAULT_PAGE_SIZE 1024
244#endif
245#if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
246# undef SQLITE_DEFAULT_PAGE_SIZE
247# define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
248#endif
249
250/*
251** Ordinarily, if no value is explicitly provided, SQLite creates databases
252** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
253** device characteristics (sector-size and atomic write() support),
254** SQLite may choose a larger value. This constant is the maximum value
255** SQLite will choose on its own.
256*/
257#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
258# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
259#endif
260#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
261# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
262# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
263#endif
264
265
266/*
267** Maximum number of pages in one database file.
268**
269** This is really just the default value for the max_page_count pragma.
270** This value can be lowered (or raised) at run-time using that the
271** max_page_count macro.
272*/
273#ifndef SQLITE_MAX_PAGE_COUNT
274# define SQLITE_MAX_PAGE_COUNT 1073741823
275#endif
276
277/*
278** Maximum length (in bytes) of the pattern in a LIKE or GLOB
279** operator.
280*/
281#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
282# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
283#endif
284
285/*
286** Maximum depth of recursion for triggers.
287**
288** A value of 1 means that a trigger program will not be able to itself
289** fire any triggers. A value of 0 means that no trigger programs at all
290** may be executed.
291*/
292#ifndef SQLITE_MAX_TRIGGER_DEPTH
293# define SQLITE_MAX_TRIGGER_DEPTH 1000
294#endif
295
296/************** End of sqliteLimit.h *****************************************/
297/************** Continuing where we left off in sqliteInt.h ******************/
298
299/* Disable nuisance warnings on Borland compilers */
300#if defined(__BORLANDC__)
301#pragma warn -rch /* unreachable code */
302#pragma warn -ccc /* Condition is always true or false */
303#pragma warn -aus /* Assigned value is never used */
304#pragma warn -csu /* Comparing signed and unsigned */
305#pragma warn -spa /* Suspicious pointer arithmetic */
306#endif
307
308/* Needed for various definitions... */
309#ifndef _GNU_SOURCE
310# define _GNU_SOURCE
311#endif
312
313/*
314** Include standard header files as necessary
315*/
316#ifdef HAVE_STDINT_H
317#include <stdint.h>
318#endif
319#ifdef HAVE_INTTYPES_H
320#include <inttypes.h>
321#endif
322
323/*
324** The number of samples of an index that SQLite takes in order to
325** construct a histogram of the table content when running ANALYZE
326** and with SQLITE_ENABLE_STAT2
327*/
328#define SQLITE_INDEX_SAMPLES 10
329
330/*
331** The following macros are used to cast pointers to integers and
332** integers to pointers.  The way you do this varies from one compiler
333** to the next, so we have developed the following set of #if statements
334** to generate appropriate macros for a wide range of compilers.
335**
336** The correct "ANSI" way to do this is to use the intptr_t type.
337** Unfortunately, that typedef is not available on all compilers, or
338** if it is available, it requires an #include of specific headers
339** that vary from one machine to the next.
340**
341** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
342** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
343** So we have to define the macros in different ways depending on the
344** compiler.
345*/
346#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
347# define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
348# define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
349#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
350# define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
351# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
352#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
353# define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
354# define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
355#else                          /* Generates a warning - but it always works */
356# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
357# define SQLITE_PTR_TO_INT(X)  ((int)(X))
358#endif
359
360/*
361** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
362** 0 means mutexes are permanently disable and the library is never
363** threadsafe.  1 means the library is serialized which is the highest
364** level of threadsafety.  2 means the library is multithreaded - multiple
365** threads can use SQLite as long as no two threads try to use the same
366** database connection at the same time.
367**
368** Older versions of SQLite used an optional THREADSAFE macro.
369** We support that for legacy.
370*/
371#if !defined(SQLITE_THREADSAFE)
372#if defined(THREADSAFE)
373# define SQLITE_THREADSAFE THREADSAFE
374#else
375# define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
376#endif
377#endif
378
379/*
380** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
381** It determines whether or not the features related to
382** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
383** be overridden at runtime using the sqlite3_config() API.
384*/
385#if !defined(SQLITE_DEFAULT_MEMSTATUS)
386# define SQLITE_DEFAULT_MEMSTATUS 1
387#endif
388
389/*
390** Exactly one of the following macros must be defined in order to
391** specify which memory allocation subsystem to use.
392**
393**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
394**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
395**
396** (Historical note:  There used to be several other options, but we've
397** pared it down to just these two.)
398**
399** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
400** the default.
401*/
402#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)>1
403# error "At most one of the following compile-time configuration options\
404 is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG"
405#endif
406#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)==0
407# define SQLITE_SYSTEM_MALLOC 1
408#endif
409
410/*
411** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
412** sizes of memory allocations below this value where possible.
413*/
414#if !defined(SQLITE_MALLOC_SOFT_LIMIT)
415# define SQLITE_MALLOC_SOFT_LIMIT 1024
416#endif
417
418/*
419** We need to define _XOPEN_SOURCE as follows in order to enable
420** recursive mutexes on most Unix systems.  But Mac OS X is different.
421** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
422** so it is omitted there.  See ticket #2673.
423**
424** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
425** implemented on some systems.  So we avoid defining it at all
426** if it is already defined or if it is unneeded because we are
427** not doing a threadsafe build.  Ticket #2681.
428**
429** See also ticket #2741.
430*/
431#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
432#  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
433#endif
434
435/*
436** The TCL headers are only needed when compiling the TCL bindings.
437*/
438#if defined(SQLITE_TCL) || defined(TCLSH)
439# include <tcl.h>
440#endif
441
442/*
443** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
444** Setting NDEBUG makes the code smaller and run faster.  So the following
445** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
446** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
447** feature.
448*/
449#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
450# define NDEBUG 1
451#endif
452
453/*
454** The testcase() macro is used to aid in coverage testing.  When
455** doing coverage testing, the condition inside the argument to
456** testcase() must be evaluated both true and false in order to
457** get full branch coverage.  The testcase() macro is inserted
458** to help ensure adequate test coverage in places where simple
459** condition/decision coverage is inadequate.  For example, testcase()
460** can be used to make sure boundary values are tested.  For
461** bitmask tests, testcase() can be used to make sure each bit
462** is significant and used at least once.  On switch statements
463** where multiple cases go to the same block of code, testcase()
464** can insure that all cases are evaluated.
465**
466*/
467#ifdef SQLITE_COVERAGE_TEST
468SQLITE_PRIVATE   void sqlite3Coverage(int);
469# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
470#else
471# define testcase(X)
472#endif
473
474/*
475** The TESTONLY macro is used to enclose variable declarations or
476** other bits of code that are needed to support the arguments
477** within testcase() and assert() macros.
478*/
479#if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
480# define TESTONLY(X)  X
481#else
482# define TESTONLY(X)
483#endif
484
485/*
486** Sometimes we need a small amount of code such as a variable initialization
487** to setup for a later assert() statement.  We do not want this code to
488** appear when assert() is disabled.  The following macro is therefore
489** used to contain that setup code.  The "VVA" acronym stands for
490** "Verification, Validation, and Accreditation".  In other words, the
491** code within VVA_ONLY() will only run during verification processes.
492*/
493#ifndef NDEBUG
494# define VVA_ONLY(X)  X
495#else
496# define VVA_ONLY(X)
497#endif
498
499/*
500** The ALWAYS and NEVER macros surround boolean expressions which
501** are intended to always be true or false, respectively.  Such
502** expressions could be omitted from the code completely.  But they
503** are included in a few cases in order to enhance the resilience
504** of SQLite to unexpected behavior - to make the code "self-healing"
505** or "ductile" rather than being "brittle" and crashing at the first
506** hint of unplanned behavior.
507**
508** In other words, ALWAYS and NEVER are added for defensive code.
509**
510** When doing coverage testing ALWAYS and NEVER are hard-coded to
511** be true and false so that the unreachable code then specify will
512** not be counted as untested code.
513*/
514#if defined(SQLITE_COVERAGE_TEST)
515# define ALWAYS(X)      (1)
516# define NEVER(X)       (0)
517#elif !defined(NDEBUG)
518# define ALWAYS(X)      ((X)?1:(assert(0),0))
519# define NEVER(X)       ((X)?(assert(0),1):0)
520#else
521# define ALWAYS(X)      (X)
522# define NEVER(X)       (X)
523#endif
524
525/*
526** Return true (non-zero) if the input is a integer that is too large
527** to fit in 32-bits.  This macro is used inside of various testcase()
528** macros to verify that we have tested SQLite for large-file support.
529*/
530#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
531
532/*
533** The macro unlikely() is a hint that surrounds a boolean
534** expression that is usually false.  Macro likely() surrounds
535** a boolean expression that is usually true.  GCC is able to
536** use these hints to generate better code, sometimes.
537*/
538#if defined(__GNUC__) && 0
539# define likely(X)    __builtin_expect((X),1)
540# define unlikely(X)  __builtin_expect((X),0)
541#else
542# define likely(X)    !!(X)
543# define unlikely(X)  !!(X)
544#endif
545
546/************** Include sqlite3.h in the middle of sqliteInt.h ***************/
547/************** Begin file sqlite3.h *****************************************/
548/*
549** 2001 September 15
550**
551** The author disclaims copyright to this source code.  In place of
552** a legal notice, here is a blessing:
553**
554**    May you do good and not evil.
555**    May you find forgiveness for yourself and forgive others.
556**    May you share freely, never taking more than you give.
557**
558*************************************************************************
559** This header file defines the interface that the SQLite library
560** presents to client programs.  If a C-function, structure, datatype,
561** or constant definition does not appear in this file, then it is
562** not a published API of SQLite, is subject to change without
563** notice, and should not be referenced by programs that use SQLite.
564**
565** Some of the definitions that are in this file are marked as
566** "experimental".  Experimental interfaces are normally new
567** features recently added to SQLite.  We do not anticipate changes
568** to experimental interfaces but reserve the right to make minor changes
569** if experience from use "in the wild" suggest such changes are prudent.
570**
571** The official C-language API documentation for SQLite is derived
572** from comments in this file.  This file is the authoritative source
573** on how SQLite interfaces are suppose to operate.
574**
575** The name of this file under configuration management is "sqlite.h.in".
576** The makefile makes some minor changes to this file (such as inserting
577** the version number) and changes its name to "sqlite3.h" as
578** part of the build process.
579*/
580#ifndef _SQLITE3_H_
581#define _SQLITE3_H_
582#include <stdarg.h>     /* Needed for the definition of va_list */
583
584/*
585** Make sure we can call this stuff from C++.
586*/
587#if 0
588extern "C" {
589#endif
590
591
592/*
593** Add the ability to override 'extern'
594*/
595#ifndef SQLITE_EXTERN
596# define SQLITE_EXTERN extern
597#endif
598
599#ifndef SQLITE_API
600# define SQLITE_API
601#endif
602
603
604/*
605** These no-op macros are used in front of interfaces to mark those
606** interfaces as either deprecated or experimental.  New applications
607** should not use deprecated interfaces - they are support for backwards
608** compatibility only.  Application writers should be aware that
609** experimental interfaces are subject to change in point releases.
610**
611** These macros used to resolve to various kinds of compiler magic that
612** would generate warning messages when they were used.  But that
613** compiler magic ended up generating such a flurry of bug reports
614** that we have taken it all out and gone back to using simple
615** noop macros.
616*/
617#define SQLITE_DEPRECATED
618#define SQLITE_EXPERIMENTAL
619
620/*
621** Ensure these symbols were not defined by some previous header file.
622*/
623#ifdef SQLITE_VERSION
624# undef SQLITE_VERSION
625#endif
626#ifdef SQLITE_VERSION_NUMBER
627# undef SQLITE_VERSION_NUMBER
628#endif
629
630/*
631** CAPI3REF: Compile-Time Library Version Numbers
632**
633** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
634** evaluates to a string literal that is the SQLite version in the
635** format "X.Y.Z" where X is the major version number (always 3 for
636** SQLite3) and Y is the minor version number and Z is the release number.)^
637** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
638** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
639** numbers used in [SQLITE_VERSION].)^
640** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
641** be larger than the release from which it is derived.  Either Y will
642** be held constant and Z will be incremented or else Y will be incremented
643** and Z will be reset to zero.
644**
645** Since version 3.6.18, SQLite source code has been stored in the
646** <a href="http://www.fossil-scm.org/">Fossil configuration management
647** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
648** a string which identifies a particular check-in of SQLite
649** within its configuration management system.  ^The SQLITE_SOURCE_ID
650** string contains the date and time of the check-in (UTC) and an SHA1
651** hash of the entire source tree.
652**
653** See also: [sqlite3_libversion()],
654** [sqlite3_libversion_number()], [sqlite3_sourceid()],
655** [sqlite_version()] and [sqlite_source_id()].
656*/
657#define SQLITE_VERSION        "3.7.7.1"
658#define SQLITE_VERSION_NUMBER 3007007
659#define SQLITE_SOURCE_ID      "2011-06-28 17:39:05 af0d91adf497f5f36ec3813f04235a6e195a605f"
660
661/*
662** CAPI3REF: Run-Time Library Version Numbers
663** KEYWORDS: sqlite3_version, sqlite3_sourceid
664**
665** These interfaces provide the same information as the [SQLITE_VERSION],
666** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
667** but are associated with the library instead of the header file.  ^(Cautious
668** programmers might include assert() statements in their application to
669** verify that values returned by these interfaces match the macros in
670** the header, and thus insure that the application is
671** compiled with matching library and header files.
672**
673** <blockquote><pre>
674** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
675** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
676** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
677** </pre></blockquote>)^
678**
679** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
680** macro.  ^The sqlite3_libversion() function returns a pointer to the
681** to the sqlite3_version[] string constant.  The sqlite3_libversion()
682** function is provided for use in DLLs since DLL users usually do not have
683** direct access to string constants within the DLL.  ^The
684** sqlite3_libversion_number() function returns an integer equal to
685** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
686** a pointer to a string constant whose value is the same as the
687** [SQLITE_SOURCE_ID] C preprocessor macro.
688**
689** See also: [sqlite_version()] and [sqlite_source_id()].
690*/
691SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
692SQLITE_API const char *sqlite3_libversion(void);
693SQLITE_API const char *sqlite3_sourceid(void);
694SQLITE_API int sqlite3_libversion_number(void);
695
696/*
697** CAPI3REF: Run-Time Library Compilation Options Diagnostics
698**
699** ^The sqlite3_compileoption_used() function returns 0 or 1
700** indicating whether the specified option was defined at
701** compile time.  ^The SQLITE_ prefix may be omitted from the
702** option name passed to sqlite3_compileoption_used().
703**
704** ^The sqlite3_compileoption_get() function allows iterating
705** over the list of options that were defined at compile time by
706** returning the N-th compile time option string.  ^If N is out of range,
707** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
708** prefix is omitted from any strings returned by
709** sqlite3_compileoption_get().
710**
711** ^Support for the diagnostic functions sqlite3_compileoption_used()
712** and sqlite3_compileoption_get() may be omitted by specifying the
713** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
714**
715** See also: SQL functions [sqlite_compileoption_used()] and
716** [sqlite_compileoption_get()] and the [compile_options pragma].
717*/
718#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
719SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
720SQLITE_API const char *sqlite3_compileoption_get(int N);
721#endif
722
723/*
724** CAPI3REF: Test To See If The Library Is Threadsafe
725**
726** ^The sqlite3_threadsafe() function returns zero if and only if
727** SQLite was compiled mutexing code omitted due to the
728** [SQLITE_THREADSAFE] compile-time option being set to 0.
729**
730** SQLite can be compiled with or without mutexes.  When
731** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
732** are enabled and SQLite is threadsafe.  When the
733** [SQLITE_THREADSAFE] macro is 0,
734** the mutexes are omitted.  Without the mutexes, it is not safe
735** to use SQLite concurrently from more than one thread.
736**
737** Enabling mutexes incurs a measurable performance penalty.
738** So if speed is of utmost importance, it makes sense to disable
739** the mutexes.  But for maximum safety, mutexes should be enabled.
740** ^The default behavior is for mutexes to be enabled.
741**
742** This interface can be used by an application to make sure that the
743** version of SQLite that it is linking against was compiled with
744** the desired setting of the [SQLITE_THREADSAFE] macro.
745**
746** This interface only reports on the compile-time mutex setting
747** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
748** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
749** can be fully or partially disabled using a call to [sqlite3_config()]
750** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
751** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
752** sqlite3_threadsafe() function shows only the compile-time setting of
753** thread safety, not any run-time changes to that setting made by
754** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
755** is unchanged by calls to sqlite3_config().)^
756**
757** See the [threading mode] documentation for additional information.
758*/
759SQLITE_API int sqlite3_threadsafe(void);
760
761/*
762** CAPI3REF: Database Connection Handle
763** KEYWORDS: {database connection} {database connections}
764**
765** Each open SQLite database is represented by a pointer to an instance of
766** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
767** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
768** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
769** is its destructor.  There are many other interfaces (such as
770** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
771** [sqlite3_busy_timeout()] to name but three) that are methods on an
772** sqlite3 object.
773*/
774typedef struct sqlite3 sqlite3;
775
776/*
777** CAPI3REF: 64-Bit Integer Types
778** KEYWORDS: sqlite_int64 sqlite_uint64
779**
780** Because there is no cross-platform way to specify 64-bit integer types
781** SQLite includes typedefs for 64-bit signed and unsigned integers.
782**
783** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
784** The sqlite_int64 and sqlite_uint64 types are supported for backwards
785** compatibility only.
786**
787** ^The sqlite3_int64 and sqlite_int64 types can store integer values
788** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
789** sqlite3_uint64 and sqlite_uint64 types can store integer values
790** between 0 and +18446744073709551615 inclusive.
791*/
792#ifdef SQLITE_INT64_TYPE
793  typedef SQLITE_INT64_TYPE sqlite_int64;
794  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
795#elif defined(_MSC_VER) || defined(__BORLANDC__)
796  typedef __int64 sqlite_int64;
797  typedef unsigned __int64 sqlite_uint64;
798#else
799  typedef long long int sqlite_int64;
800  typedef unsigned long long int sqlite_uint64;
801#endif
802typedef sqlite_int64 sqlite3_int64;
803typedef sqlite_uint64 sqlite3_uint64;
804
805/*
806** If compiling for a processor that lacks floating point support,
807** substitute integer for floating-point.
808*/
809#ifdef SQLITE_OMIT_FLOATING_POINT
810# define double sqlite3_int64
811#endif
812
813/*
814** CAPI3REF: Closing A Database Connection
815**
816** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
817** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
818** successfully destroyed and all associated resources are deallocated.
819**
820** Applications must [sqlite3_finalize | finalize] all [prepared statements]
821** and [sqlite3_blob_close | close] all [BLOB handles] associated with
822** the [sqlite3] object prior to attempting to close the object.  ^If
823** sqlite3_close() is called on a [database connection] that still has
824** outstanding [prepared statements] or [BLOB handles], then it returns
825** SQLITE_BUSY.
826**
827** ^If [sqlite3_close()] is invoked while a transaction is open,
828** the transaction is automatically rolled back.
829**
830** The C parameter to [sqlite3_close(C)] must be either a NULL
831** pointer or an [sqlite3] object pointer obtained
832** from [sqlite3_open()], [sqlite3_open16()], or
833** [sqlite3_open_v2()], and not previously closed.
834** ^Calling sqlite3_close() with a NULL pointer argument is a
835** harmless no-op.
836*/
837SQLITE_API int sqlite3_close(sqlite3 *);
838
839/*
840** The type for a callback function.
841** This is legacy and deprecated.  It is included for historical
842** compatibility and is not documented.
843*/
844typedef int (*sqlite3_callback)(void*,int,char**, char**);
845
846/*
847** CAPI3REF: One-Step Query Execution Interface
848**
849** The sqlite3_exec() interface is a convenience wrapper around
850** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
851** that allows an application to run multiple statements of SQL
852** without having to use a lot of C code.
853**
854** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
855** semicolon-separate SQL statements passed into its 2nd argument,
856** in the context of the [database connection] passed in as its 1st
857** argument.  ^If the callback function of the 3rd argument to
858** sqlite3_exec() is not NULL, then it is invoked for each result row
859** coming out of the evaluated SQL statements.  ^The 4th argument to
860** sqlite3_exec() is relayed through to the 1st argument of each
861** callback invocation.  ^If the callback pointer to sqlite3_exec()
862** is NULL, then no callback is ever invoked and result rows are
863** ignored.
864**
865** ^If an error occurs while evaluating the SQL statements passed into
866** sqlite3_exec(), then execution of the current statement stops and
867** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
868** is not NULL then any error message is written into memory obtained
869** from [sqlite3_malloc()] and passed back through the 5th parameter.
870** To avoid memory leaks, the application should invoke [sqlite3_free()]
871** on error message strings returned through the 5th parameter of
872** of sqlite3_exec() after the error message string is no longer needed.
873** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
874** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
875** NULL before returning.
876**
877** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
878** routine returns SQLITE_ABORT without invoking the callback again and
879** without running any subsequent SQL statements.
880**
881** ^The 2nd argument to the sqlite3_exec() callback function is the
882** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
883** callback is an array of pointers to strings obtained as if from
884** [sqlite3_column_text()], one for each column.  ^If an element of a
885** result row is NULL then the corresponding string pointer for the
886** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
887** sqlite3_exec() callback is an array of pointers to strings where each
888** entry represents the name of corresponding result column as obtained
889** from [sqlite3_column_name()].
890**
891** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
892** to an empty string, or a pointer that contains only whitespace and/or
893** SQL comments, then no SQL statements are evaluated and the database
894** is not changed.
895**
896** Restrictions:
897**
898** <ul>
899** <li> The application must insure that the 1st parameter to sqlite3_exec()
900**      is a valid and open [database connection].
901** <li> The application must not close [database connection] specified by
902**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
903** <li> The application must not modify the SQL statement text passed into
904**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
905** </ul>
906*/
907SQLITE_API int sqlite3_exec(
908  sqlite3*,                                  /* An open database */
909  const char *sql,                           /* SQL to be evaluated */
910  int (*callback)(void*,int,char**,char**),  /* Callback function */
911  void *,                                    /* 1st argument to callback */
912  char **errmsg                              /* Error msg written here */
913);
914
915/*
916** CAPI3REF: Result Codes
917** KEYWORDS: SQLITE_OK {error code} {error codes}
918** KEYWORDS: {result code} {result codes}
919**
920** Many SQLite functions return an integer result code from the set shown
921** here in order to indicates success or failure.
922**
923** New error codes may be added in future versions of SQLite.
924**
925** See also: [SQLITE_IOERR_READ | extended result codes],
926** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
927*/
928#define SQLITE_OK           0   /* Successful result */
929/* beginning-of-error-codes */
930#define SQLITE_ERROR        1   /* SQL error or missing database */
931#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
932#define SQLITE_PERM         3   /* Access permission denied */
933#define SQLITE_ABORT        4   /* Callback routine requested an abort */
934#define SQLITE_BUSY         5   /* The database file is locked */
935#define SQLITE_LOCKED       6   /* A table in the database is locked */
936#define SQLITE_NOMEM        7   /* A malloc() failed */
937#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
938#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
939#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
940#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
941#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
942#define SQLITE_FULL        13   /* Insertion failed because database is full */
943#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
944#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
945#define SQLITE_EMPTY       16   /* Database is empty */
946#define SQLITE_SCHEMA      17   /* The database schema changed */
947#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
948#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
949#define SQLITE_MISMATCH    20   /* Data type mismatch */
950#define SQLITE_MISUSE      21   /* Library used incorrectly */
951#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
952#define SQLITE_AUTH        23   /* Authorization denied */
953#define SQLITE_FORMAT      24   /* Auxiliary database format error */
954#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
955#define SQLITE_NOTADB      26   /* File opened that is not a database file */
956#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
957#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
958/* end-of-error-codes */
959
960/*
961** CAPI3REF: Extended Result Codes
962** KEYWORDS: {extended error code} {extended error codes}
963** KEYWORDS: {extended result code} {extended result codes}
964**
965** In its default configuration, SQLite API routines return one of 26 integer
966** [SQLITE_OK | result codes].  However, experience has shown that many of
967** these result codes are too coarse-grained.  They do not provide as
968** much information about problems as programmers might like.  In an effort to
969** address this, newer versions of SQLite (version 3.3.8 and later) include
970** support for additional result codes that provide more detailed information
971** about errors. The extended result codes are enabled or disabled
972** on a per database connection basis using the
973** [sqlite3_extended_result_codes()] API.
974**
975** Some of the available extended result codes are listed here.
976** One may expect the number of extended result codes will be expand
977** over time.  Software that uses extended result codes should expect
978** to see new result codes in future releases of SQLite.
979**
980** The SQLITE_OK result code will never be extended.  It will always
981** be exactly zero.
982*/
983#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
984#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
985#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
986#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
987#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
988#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
989#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
990#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
991#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
992#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
993#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
994#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
995#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
996#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
997#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
998#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
999#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
1000#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
1001#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
1002#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
1003#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
1004#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
1005#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
1006#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
1007#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
1008#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
1009#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
1010#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
1011
1012/*
1013** CAPI3REF: Flags For File Open Operations
1014**
1015** These bit values are intended for use in the
1016** 3rd parameter to the [sqlite3_open_v2()] interface and
1017** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
1018*/
1019#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
1020#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
1021#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
1022#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
1023#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
1024#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
1025#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
1026#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
1027#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
1028#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
1029#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
1030#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
1031#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
1032#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
1033#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
1034#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
1035#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
1036#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
1037#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
1038
1039/* Reserved:                         0x00F00000 */
1040
1041/*
1042** CAPI3REF: Device Characteristics
1043**
1044** The xDeviceCharacteristics method of the [sqlite3_io_methods]
1045** object returns an integer which is a vector of the these
1046** bit values expressing I/O characteristics of the mass storage
1047** device that holds the file that the [sqlite3_io_methods]
1048** refers to.
1049**
1050** The SQLITE_IOCAP_ATOMIC property means that all writes of
1051** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
1052** mean that writes of blocks that are nnn bytes in size and
1053** are aligned to an address which is an integer multiple of
1054** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
1055** that when data is appended to a file, the data is appended
1056** first then the size of the file is extended, never the other
1057** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
1058** information is written to disk in the same order as calls
1059** to xWrite().
1060*/
1061#define SQLITE_IOCAP_ATOMIC                 0x00000001
1062#define SQLITE_IOCAP_ATOMIC512              0x00000002
1063#define SQLITE_IOCAP_ATOMIC1K               0x00000004
1064#define SQLITE_IOCAP_ATOMIC2K               0x00000008
1065#define SQLITE_IOCAP_ATOMIC4K               0x00000010
1066#define SQLITE_IOCAP_ATOMIC8K               0x00000020
1067#define SQLITE_IOCAP_ATOMIC16K              0x00000040
1068#define SQLITE_IOCAP_ATOMIC32K              0x00000080
1069#define SQLITE_IOCAP_ATOMIC64K              0x00000100
1070#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
1071#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
1072#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
1073
1074/*
1075** CAPI3REF: File Locking Levels
1076**
1077** SQLite uses one of these integer values as the second
1078** argument to calls it makes to the xLock() and xUnlock() methods
1079** of an [sqlite3_io_methods] object.
1080*/
1081#define SQLITE_LOCK_NONE          0
1082#define SQLITE_LOCK_SHARED        1
1083#define SQLITE_LOCK_RESERVED      2
1084#define SQLITE_LOCK_PENDING       3
1085#define SQLITE_LOCK_EXCLUSIVE     4
1086
1087/*
1088** CAPI3REF: Synchronization Type Flags
1089**
1090** When SQLite invokes the xSync() method of an
1091** [sqlite3_io_methods] object it uses a combination of
1092** these integer values as the second argument.
1093**
1094** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
1095** sync operation only needs to flush data to mass storage.  Inode
1096** information need not be flushed. If the lower four bits of the flag
1097** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
1098** If the lower four bits equal SQLITE_SYNC_FULL, that means
1099** to use Mac OS X style fullsync instead of fsync().
1100**
1101** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
1102** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
1103** settings.  The [synchronous pragma] determines when calls to the
1104** xSync VFS method occur and applies uniformly across all platforms.
1105** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
1106** energetic or rigorous or forceful the sync operations are and
1107** only make a difference on Mac OSX for the default SQLite code.
1108** (Third-party VFS implementations might also make the distinction
1109** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
1110** operating systems natively supported by SQLite, only Mac OSX
1111** cares about the difference.)
1112*/
1113#define SQLITE_SYNC_NORMAL        0x00002
1114#define SQLITE_SYNC_FULL          0x00003
1115#define SQLITE_SYNC_DATAONLY      0x00010
1116
1117/*
1118** CAPI3REF: OS Interface Open File Handle
1119**
1120** An [sqlite3_file] object represents an open file in the
1121** [sqlite3_vfs | OS interface layer].  Individual OS interface
1122** implementations will
1123** want to subclass this object by appending additional fields
1124** for their own use.  The pMethods entry is a pointer to an
1125** [sqlite3_io_methods] object that defines methods for performing
1126** I/O operations on the open file.
1127*/
1128typedef struct sqlite3_file sqlite3_file;
1129struct sqlite3_file {
1130  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
1131};
1132
1133/*
1134** CAPI3REF: OS Interface File Virtual Methods Object
1135**
1136** Every file opened by the [sqlite3_vfs.xOpen] method populates an
1137** [sqlite3_file] object (or, more commonly, a subclass of the
1138** [sqlite3_file] object) with a pointer to an instance of this object.
1139** This object defines the methods used to perform various operations
1140** against the open file represented by the [sqlite3_file] object.
1141**
1142** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
1143** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
1144** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
1145** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
1146** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
1147** to NULL.
1148**
1149** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
1150** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
1151** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
1152** flag may be ORed in to indicate that only the data of the file
1153** and not its inode needs to be synced.
1154**
1155** The integer values to xLock() and xUnlock() are one of
1156** <ul>
1157** <li> [SQLITE_LOCK_NONE],
1158** <li> [SQLITE_LOCK_SHARED],
1159** <li> [SQLITE_LOCK_RESERVED],
1160** <li> [SQLITE_LOCK_PENDING], or
1161** <li> [SQLITE_LOCK_EXCLUSIVE].
1162** </ul>
1163** xLock() increases the lock. xUnlock() decreases the lock.
1164** The xCheckReservedLock() method checks whether any database connection,
1165** either in this process or in some other process, is holding a RESERVED,
1166** PENDING, or EXCLUSIVE lock on the file.  It returns true
1167** if such a lock exists and false otherwise.
1168**
1169** The xFileControl() method is a generic interface that allows custom
1170** VFS implementations to directly control an open file using the
1171** [sqlite3_file_control()] interface.  The second "op" argument is an
1172** integer opcode.  The third argument is a generic pointer intended to
1173** point to a structure that may contain arguments or space in which to
1174** write return values.  Potential uses for xFileControl() might be
1175** functions to enable blocking locks with timeouts, to change the
1176** locking strategy (for example to use dot-file locks), to inquire
1177** about the status of a lock, or to break stale locks.  The SQLite
1178** core reserves all opcodes less than 100 for its own use.
1179** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
1180** Applications that define a custom xFileControl method should use opcodes
1181** greater than 100 to avoid conflicts.  VFS implementations should
1182** return [SQLITE_NOTFOUND] for file control opcodes that they do not
1183** recognize.
1184**
1185** The xSectorSize() method returns the sector size of the
1186** device that underlies the file.  The sector size is the
1187** minimum write that can be performed without disturbing
1188** other bytes in the file.  The xDeviceCharacteristics()
1189** method returns a bit vector describing behaviors of the
1190** underlying device:
1191**
1192** <ul>
1193** <li> [SQLITE_IOCAP_ATOMIC]
1194** <li> [SQLITE_IOCAP_ATOMIC512]
1195** <li> [SQLITE_IOCAP_ATOMIC1K]
1196** <li> [SQLITE_IOCAP_ATOMIC2K]
1197** <li> [SQLITE_IOCAP_ATOMIC4K]
1198** <li> [SQLITE_IOCAP_ATOMIC8K]
1199** <li> [SQLITE_IOCAP_ATOMIC16K]
1200** <li> [SQLITE_IOCAP_ATOMIC32K]
1201** <li> [SQLITE_IOCAP_ATOMIC64K]
1202** <li> [SQLITE_IOCAP_SAFE_APPEND]
1203** <li> [SQLITE_IOCAP_SEQUENTIAL]
1204** </ul>
1205**
1206** The SQLITE_IOCAP_ATOMIC property means that all writes of
1207** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
1208** mean that writes of blocks that are nnn bytes in size and
1209** are aligned to an address which is an integer multiple of
1210** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
1211** that when data is appended to a file, the data is appended
1212** first then the size of the file is extended, never the other
1213** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
1214** information is written to disk in the same order as calls
1215** to xWrite().
1216**
1217** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
1218** in the unread portions of the buffer with zeros.  A VFS that
1219** fails to zero-fill short reads might seem to work.  However,
1220** failure to zero-fill short reads will eventually lead to
1221** database corruption.
1222*/
1223typedef struct sqlite3_io_methods sqlite3_io_methods;
1224struct sqlite3_io_methods {
1225  int iVersion;
1226  int (*xClose)(sqlite3_file*);
1227  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
1228  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
1229  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
1230  int (*xSync)(sqlite3_file*, int flags);
1231  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
1232  int (*xLock)(sqlite3_file*, int);
1233  int (*xUnlock)(sqlite3_file*, int);
1234  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
1235  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
1236  int (*xSectorSize)(sqlite3_file*);
1237  int (*xDeviceCharacteristics)(sqlite3_file*);
1238  /* Methods above are valid for version 1 */
1239  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
1240  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
1241  void (*xShmBarrier)(sqlite3_file*);
1242  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
1243  /* Methods above are valid for version 2 */
1244  /* Additional methods may be added in future releases */
1245};
1246
1247/*
1248** CAPI3REF: Standard File Control Opcodes
1249**
1250** These integer constants are opcodes for the xFileControl method
1251** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
1252** interface.
1253**
1254** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
1255** opcode causes the xFileControl method to write the current state of
1256** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
1257** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
1258** into an integer that the pArg argument points to. This capability
1259** is used during testing and only needs to be supported when SQLITE_TEST
1260** is defined.
1261**
1262** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
1263** layer a hint of how large the database file will grow to be during the
1264** current transaction.  This hint is not guaranteed to be accurate but it
1265** is often close.  The underlying VFS might choose to preallocate database
1266** file space based on this hint in order to help writes to the database
1267** file run faster.
1268**
1269** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
1270** extends and truncates the database file in chunks of a size specified
1271** by the user. The fourth argument to [sqlite3_file_control()] should
1272** point to an integer (type int) containing the new chunk-size to use
1273** for the nominated database. Allocating database file space in large
1274** chunks (say 1MB at a time), may reduce file-system fragmentation and
1275** improve performance on some systems.
1276**
1277** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
1278** to the [sqlite3_file] object associated with a particular database
1279** connection.  See the [sqlite3_file_control()] documentation for
1280** additional information.
1281**
1282** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
1283** SQLite and sent to all VFSes in place of a call to the xSync method
1284** when the database connection has [PRAGMA synchronous] set to OFF.)^
1285** Some specialized VFSes need this signal in order to operate correctly
1286** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
1287** VFSes do not need this signal and should silently ignore this opcode.
1288** Applications should not call [sqlite3_file_control()] with this
1289** opcode as doing so may disrupt the operation of the specialized VFSes
1290** that do require it.
1291*/
1292#define SQLITE_FCNTL_LOCKSTATE        1
1293#define SQLITE_GET_LOCKPROXYFILE      2
1294#define SQLITE_SET_LOCKPROXYFILE      3
1295#define SQLITE_LAST_ERRNO             4
1296#define SQLITE_FCNTL_SIZE_HINT        5
1297#define SQLITE_FCNTL_CHUNK_SIZE       6
1298#define SQLITE_FCNTL_FILE_POINTER     7
1299#define SQLITE_FCNTL_SYNC_OMITTED     8
1300
1301
1302/*
1303** CAPI3REF: Mutex Handle
1304**
1305** The mutex module within SQLite defines [sqlite3_mutex] to be an
1306** abstract type for a mutex object.  The SQLite core never looks
1307** at the internal representation of an [sqlite3_mutex].  It only
1308** deals with pointers to the [sqlite3_mutex] object.
1309**
1310** Mutexes are created using [sqlite3_mutex_alloc()].
1311*/
1312typedef struct sqlite3_mutex sqlite3_mutex;
1313
1314/*
1315** CAPI3REF: OS Interface Object
1316**
1317** An instance of the sqlite3_vfs object defines the interface between
1318** the SQLite core and the underlying operating system.  The "vfs"
1319** in the name of the object stands for "virtual file system".  See
1320** the [VFS | VFS documentation] for further information.
1321**
1322** The value of the iVersion field is initially 1 but may be larger in
1323** future versions of SQLite.  Additional fields may be appended to this
1324** object when the iVersion value is increased.  Note that the structure
1325** of the sqlite3_vfs object changes in the transaction between
1326** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1327** modified.
1328**
1329** The szOsFile field is the size of the subclassed [sqlite3_file]
1330** structure used by this VFS.  mxPathname is the maximum length of
1331** a pathname in this VFS.
1332**
1333** Registered sqlite3_vfs objects are kept on a linked list formed by
1334** the pNext pointer.  The [sqlite3_vfs_register()]
1335** and [sqlite3_vfs_unregister()] interfaces manage this list
1336** in a thread-safe way.  The [sqlite3_vfs_find()] interface
1337** searches the list.  Neither the application code nor the VFS
1338** implementation should use the pNext pointer.
1339**
1340** The pNext field is the only field in the sqlite3_vfs
1341** structure that SQLite will ever modify.  SQLite will only access
1342** or modify this field while holding a particular static mutex.
1343** The application should never modify anything within the sqlite3_vfs
1344** object once the object has been registered.
1345**
1346** The zName field holds the name of the VFS module.  The name must
1347** be unique across all VFS modules.
1348**
1349** [[sqlite3_vfs.xOpen]]
1350** ^SQLite guarantees that the zFilename parameter to xOpen
1351** is either a NULL pointer or string obtained
1352** from xFullPathname() with an optional suffix added.
1353** ^If a suffix is added to the zFilename parameter, it will
1354** consist of a single "-" character followed by no more than
1355** 10 alphanumeric and/or "-" characters.
1356** ^SQLite further guarantees that
1357** the string will be valid and unchanged until xClose() is
1358** called. Because of the previous sentence,
1359** the [sqlite3_file] can safely store a pointer to the
1360** filename if it needs to remember the filename for some reason.
1361** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1362** must invent its own temporary name for the file.  ^Whenever the
1363** xFilename parameter is NULL it will also be the case that the
1364** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1365**
1366** The flags argument to xOpen() includes all bits set in
1367** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
1368** or [sqlite3_open16()] is used, then flags includes at least
1369** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1370** If xOpen() opens a file read-only then it sets *pOutFlags to
1371** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
1372**
1373** ^(SQLite will also add one of the following flags to the xOpen()
1374** call, depending on the object being opened:
1375**
1376** <ul>
1377** <li>  [SQLITE_OPEN_MAIN_DB]
1378** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
1379** <li>  [SQLITE_OPEN_TEMP_DB]
1380** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
1381** <li>  [SQLITE_OPEN_TRANSIENT_DB]
1382** <li>  [SQLITE_OPEN_SUBJOURNAL]
1383** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
1384** <li>  [SQLITE_OPEN_WAL]
1385** </ul>)^
1386**
1387** The file I/O implementation can use the object type flags to
1388** change the way it deals with files.  For example, an application
1389** that does not care about crash recovery or rollback might make
1390** the open of a journal file a no-op.  Writes to this journal would
1391** also be no-ops, and any attempt to read the journal would return
1392** SQLITE_IOERR.  Or the implementation might recognize that a database
1393** file will be doing page-aligned sector reads and writes in a random
1394** order and set up its I/O subsystem accordingly.
1395**
1396** SQLite might also add one of the following flags to the xOpen method:
1397**
1398** <ul>
1399** <li> [SQLITE_OPEN_DELETEONCLOSE]
1400** <li> [SQLITE_OPEN_EXCLUSIVE]
1401** </ul>
1402**
1403** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1404** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
1405** will be set for TEMP databases and their journals, transient
1406** databases, and subjournals.
1407**
1408** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1409** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1410** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1411** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1412** SQLITE_OPEN_CREATE, is used to indicate that file should always
1413** be created, and that it is an error if it already exists.
1414** It is <i>not</i> used to indicate the file should be opened
1415** for exclusive access.
1416**
1417** ^At least szOsFile bytes of memory are allocated by SQLite
1418** to hold the  [sqlite3_file] structure passed as the third
1419** argument to xOpen.  The xOpen method does not have to
1420** allocate the structure; it should just fill it in.  Note that
1421** the xOpen method must set the sqlite3_file.pMethods to either
1422** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
1423** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
1424** element will be valid after xOpen returns regardless of the success
1425** or failure of the xOpen call.
1426**
1427** [[sqlite3_vfs.xAccess]]
1428** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1429** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1430** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1431** to test whether a file is at least readable.   The file can be a
1432** directory.
1433**
1434** ^SQLite will always allocate at least mxPathname+1 bytes for the
1435** output buffer xFullPathname.  The exact size of the output buffer
1436** is also passed as a parameter to both  methods. If the output buffer
1437** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1438** handled as a fatal error by SQLite, vfs implementations should endeavor
1439** to prevent this by setting mxPathname to a sufficiently large value.
1440**
1441** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1442** interfaces are not strictly a part of the filesystem, but they are
1443** included in the VFS structure for completeness.
1444** The xRandomness() function attempts to return nBytes bytes
1445** of good-quality randomness into zOut.  The return value is
1446** the actual number of bytes of randomness obtained.
1447** The xSleep() method causes the calling thread to sleep for at
1448** least the number of microseconds given.  ^The xCurrentTime()
1449** method returns a Julian Day Number for the current date and time as
1450** a floating point value.
1451** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1452** Day Number multiplied by 86400000 (the number of milliseconds in
1453** a 24-hour day).
1454** ^SQLite will use the xCurrentTimeInt64() method to get the current
1455** date and time if that method is available (if iVersion is 2 or
1456** greater and the function pointer is not NULL) and will fall back
1457** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1458**
1459** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1460** are not used by the SQLite core.  These optional interfaces are provided
1461** by some VFSes to facilitate testing of the VFS code. By overriding
1462** system calls with functions under its control, a test program can
1463** simulate faults and error conditions that would otherwise be difficult
1464** or impossible to induce.  The set of system calls that can be overridden
1465** varies from one VFS to another, and from one version of the same VFS to the
1466** next.  Applications that use these interfaces must be prepared for any
1467** or all of these interfaces to be NULL or for their behavior to change
1468** from one release to the next.  Applications must not attempt to access
1469** any of these methods if the iVersion of the VFS is less than 3.
1470*/
1471typedef struct sqlite3_vfs sqlite3_vfs;
1472typedef void (*sqlite3_syscall_ptr)(void);
1473struct sqlite3_vfs {
1474  int iVersion;            /* Structure version number (currently 3) */
1475  int szOsFile;            /* Size of subclassed sqlite3_file */
1476  int mxPathname;          /* Maximum file pathname length */
1477  sqlite3_vfs *pNext;      /* Next registered VFS */
1478  const char *zName;       /* Name of this virtual file system */
1479  void *pAppData;          /* Pointer to application-specific data */
1480  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1481               int flags, int *pOutFlags);
1482  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1483  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1484  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1485  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1486  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1487  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1488  void (*xDlClose)(sqlite3_vfs*, void*);
1489  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1490  int (*xSleep)(sqlite3_vfs*, int microseconds);
1491  int (*xCurrentTime)(sqlite3_vfs*, double*);
1492  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1493  /*
1494  ** The methods above are in version 1 of the sqlite_vfs object
1495  ** definition.  Those that follow are added in version 2 or later
1496  */
1497  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1498  /*
1499  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1500  ** Those below are for version 3 and greater.
1501  */
1502  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1503  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1504  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1505  /*
1506  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1507  ** New fields may be appended in figure versions.  The iVersion
1508  ** value will increment whenever this happens.
1509  */
1510};
1511
1512/*
1513** CAPI3REF: Flags for the xAccess VFS method
1514**
1515** These integer constants can be used as the third parameter to
1516** the xAccess method of an [sqlite3_vfs] object.  They determine
1517** what kind of permissions the xAccess method is looking for.
1518** With SQLITE_ACCESS_EXISTS, the xAccess method
1519** simply checks whether the file exists.
1520** With SQLITE_ACCESS_READWRITE, the xAccess method
1521** checks whether the named directory is both readable and writable
1522** (in other words, if files can be added, removed, and renamed within
1523** the directory).
1524** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1525** [temp_store_directory pragma], though this could change in a future
1526** release of SQLite.
1527** With SQLITE_ACCESS_READ, the xAccess method
1528** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
1529** currently unused, though it might be used in a future release of
1530** SQLite.
1531*/
1532#define SQLITE_ACCESS_EXISTS    0
1533#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
1534#define SQLITE_ACCESS_READ      2   /* Unused */
1535
1536/*
1537** CAPI3REF: Flags for the xShmLock VFS method
1538**
1539** These integer constants define the various locking operations
1540** allowed by the xShmLock method of [sqlite3_io_methods].  The
1541** following are the only legal combinations of flags to the
1542** xShmLock method:
1543**
1544** <ul>
1545** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1546** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1547** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1548** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1549** </ul>
1550**
1551** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1552** was given no the corresponding lock.
1553**
1554** The xShmLock method can transition between unlocked and SHARED or
1555** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
1556** and EXCLUSIVE.
1557*/
1558#define SQLITE_SHM_UNLOCK       1
1559#define SQLITE_SHM_LOCK         2
1560#define SQLITE_SHM_SHARED       4
1561#define SQLITE_SHM_EXCLUSIVE    8
1562
1563/*
1564** CAPI3REF: Maximum xShmLock index
1565**
1566** The xShmLock method on [sqlite3_io_methods] may use values
1567** between 0 and this upper bound as its "offset" argument.
1568** The SQLite core will never attempt to acquire or release a
1569** lock outside of this range
1570*/
1571#define SQLITE_SHM_NLOCK        8
1572
1573
1574/*
1575** CAPI3REF: Initialize The SQLite Library
1576**
1577** ^The sqlite3_initialize() routine initializes the
1578** SQLite library.  ^The sqlite3_shutdown() routine
1579** deallocates any resources that were allocated by sqlite3_initialize().
1580** These routines are designed to aid in process initialization and
1581** shutdown on embedded systems.  Workstation applications using
1582** SQLite normally do not need to invoke either of these routines.
1583**
1584** A call to sqlite3_initialize() is an "effective" call if it is
1585** the first time sqlite3_initialize() is invoked during the lifetime of
1586** the process, or if it is the first time sqlite3_initialize() is invoked
1587** following a call to sqlite3_shutdown().  ^(Only an effective call
1588** of sqlite3_initialize() does any initialization.  All other calls
1589** are harmless no-ops.)^
1590**
1591** A call to sqlite3_shutdown() is an "effective" call if it is the first
1592** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
1593** an effective call to sqlite3_shutdown() does any deinitialization.
1594** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1595**
1596** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1597** is not.  The sqlite3_shutdown() interface must only be called from a
1598** single thread.  All open [database connections] must be closed and all
1599** other SQLite resources must be deallocated prior to invoking
1600** sqlite3_shutdown().
1601**
1602** Among other things, ^sqlite3_initialize() will invoke
1603** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
1604** will invoke sqlite3_os_end().
1605**
1606** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1607** ^If for some reason, sqlite3_initialize() is unable to initialize
1608** the library (perhaps it is unable to allocate a needed resource such
1609** as a mutex) it returns an [error code] other than [SQLITE_OK].
1610**
1611** ^The sqlite3_initialize() routine is called internally by many other
1612** SQLite interfaces so that an application usually does not need to
1613** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
1614** calls sqlite3_initialize() so the SQLite library will be automatically
1615** initialized when [sqlite3_open()] is called if it has not be initialized
1616** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1617** compile-time option, then the automatic calls to sqlite3_initialize()
1618** are omitted and the application must call sqlite3_initialize() directly
1619** prior to using any other SQLite interface.  For maximum portability,
1620** it is recommended that applications always invoke sqlite3_initialize()
1621** directly prior to using any other SQLite interface.  Future releases
1622** of SQLite may require this.  In other words, the behavior exhibited
1623** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1624** default behavior in some future release of SQLite.
1625**
1626** The sqlite3_os_init() routine does operating-system specific
1627** initialization of the SQLite library.  The sqlite3_os_end()
1628** routine undoes the effect of sqlite3_os_init().  Typical tasks
1629** performed by these routines include allocation or deallocation
1630** of static resources, initialization of global variables,
1631** setting up a default [sqlite3_vfs] module, or setting up
1632** a default configuration using [sqlite3_config()].
1633**
1634** The application should never invoke either sqlite3_os_init()
1635** or sqlite3_os_end() directly.  The application should only invoke
1636** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
1637** interface is called automatically by sqlite3_initialize() and
1638** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
1639** implementations for sqlite3_os_init() and sqlite3_os_end()
1640** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1641** When [custom builds | built for other platforms]
1642** (using the [SQLITE_OS_OTHER=1] compile-time
1643** option) the application must supply a suitable implementation for
1644** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
1645** implementation of sqlite3_os_init() or sqlite3_os_end()
1646** must return [SQLITE_OK] on success and some other [error code] upon
1647** failure.
1648*/
1649SQLITE_API int sqlite3_initialize(void);
1650SQLITE_API int sqlite3_shutdown(void);
1651SQLITE_API int sqlite3_os_init(void);
1652SQLITE_API int sqlite3_os_end(void);
1653
1654/*
1655** CAPI3REF: Configuring The SQLite Library
1656**
1657** The sqlite3_config() interface is used to make global configuration
1658** changes to SQLite in order to tune SQLite to the specific needs of
1659** the application.  The default configuration is recommended for most
1660** applications and so this routine is usually not necessary.  It is
1661** provided to support rare applications with unusual needs.
1662**
1663** The sqlite3_config() interface is not threadsafe.  The application
1664** must insure that no other SQLite interfaces are invoked by other
1665** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
1666** may only be invoked prior to library initialization using
1667** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1668** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1669** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1670** Note, however, that ^sqlite3_config() can be called as part of the
1671** implementation of an application-defined [sqlite3_os_init()].
1672**
1673** The first argument to sqlite3_config() is an integer
1674** [configuration option] that determines
1675** what property of SQLite is to be configured.  Subsequent arguments
1676** vary depending on the [configuration option]
1677** in the first argument.
1678**
1679** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1680** ^If the option is unknown or SQLite is unable to set the option
1681** then this routine returns a non-zero [error code].
1682*/
1683SQLITE_API int sqlite3_config(int, ...);
1684
1685/*
1686** CAPI3REF: Configure database connections
1687**
1688** The sqlite3_db_config() interface is used to make configuration
1689** changes to a [database connection].  The interface is similar to
1690** [sqlite3_config()] except that the changes apply to a single
1691** [database connection] (specified in the first argument).
1692**
1693** The second argument to sqlite3_db_config(D,V,...)  is the
1694** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1695** that indicates what aspect of the [database connection] is being configured.
1696** Subsequent arguments vary depending on the configuration verb.
1697**
1698** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1699** the call is considered successful.
1700*/
1701SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1702
1703/*
1704** CAPI3REF: Memory Allocation Routines
1705**
1706** An instance of this object defines the interface between SQLite
1707** and low-level memory allocation routines.
1708**
1709** This object is used in only one place in the SQLite interface.
1710** A pointer to an instance of this object is the argument to
1711** [sqlite3_config()] when the configuration option is
1712** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1713** By creating an instance of this object
1714** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1715** during configuration, an application can specify an alternative
1716** memory allocation subsystem for SQLite to use for all of its
1717** dynamic memory needs.
1718**
1719** Note that SQLite comes with several [built-in memory allocators]
1720** that are perfectly adequate for the overwhelming majority of applications
1721** and that this object is only useful to a tiny minority of applications
1722** with specialized memory allocation requirements.  This object is
1723** also used during testing of SQLite in order to specify an alternative
1724** memory allocator that simulates memory out-of-memory conditions in
1725** order to verify that SQLite recovers gracefully from such
1726** conditions.
1727**
1728** The xMalloc and xFree methods must work like the
1729** malloc() and free() functions from the standard C library.
1730** The xRealloc method must work like realloc() from the standard C library
1731** with the exception that if the second argument to xRealloc is zero,
1732** xRealloc must be a no-op - it must not perform any allocation or
1733** deallocation.  ^SQLite guarantees that the second argument to
1734** xRealloc is always a value returned by a prior call to xRoundup.
1735** And so in cases where xRoundup always returns a positive number,
1736** xRealloc can perform exactly as the standard library realloc() and
1737** still be in compliance with this specification.
1738**
1739** xSize should return the allocated size of a memory allocation
1740** previously obtained from xMalloc or xRealloc.  The allocated size
1741** is always at least as big as the requested size but may be larger.
1742**
1743** The xRoundup method returns what would be the allocated size of
1744** a memory allocation given a particular requested size.  Most memory
1745** allocators round up memory allocations at least to the next multiple
1746** of 8.  Some allocators round up to a larger multiple or to a power of 2.
1747** Every memory allocation request coming in through [sqlite3_malloc()]
1748** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
1749** that causes the corresponding memory allocation to fail.
1750**
1751** The xInit method initializes the memory allocator.  (For example,
1752** it might allocate any require mutexes or initialize internal data
1753** structures.  The xShutdown method is invoked (indirectly) by
1754** [sqlite3_shutdown()] and should deallocate any resources acquired
1755** by xInit.  The pAppData pointer is used as the only parameter to
1756** xInit and xShutdown.
1757**
1758** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1759** the xInit method, so the xInit method need not be threadsafe.  The
1760** xShutdown method is only called from [sqlite3_shutdown()] so it does
1761** not need to be threadsafe either.  For all other methods, SQLite
1762** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1763** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1764** it is by default) and so the methods are automatically serialized.
1765** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1766** methods must be threadsafe or else make their own arrangements for
1767** serialization.
1768**
1769** SQLite will never invoke xInit() more than once without an intervening
1770** call to xShutdown().
1771*/
1772typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1773struct sqlite3_mem_methods {
1774  void *(*xMalloc)(int);         /* Memory allocation function */
1775  void (*xFree)(void*);          /* Free a prior allocation */
1776  void *(*xRealloc)(void*,int);  /* Resize an allocation */
1777  int (*xSize)(void*);           /* Return the size of an allocation */
1778  int (*xRoundup)(int);          /* Round up request size to allocation size */
1779  int (*xInit)(void*);           /* Initialize the memory allocator */
1780  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
1781  void *pAppData;                /* Argument to xInit() and xShutdown() */
1782};
1783
1784/*
1785** CAPI3REF: Configuration Options
1786** KEYWORDS: {configuration option}
1787**
1788** These constants are the available integer configuration options that
1789** can be passed as the first argument to the [sqlite3_config()] interface.
1790**
1791** New configuration options may be added in future releases of SQLite.
1792** Existing configuration options might be discontinued.  Applications
1793** should check the return code from [sqlite3_config()] to make sure that
1794** the call worked.  The [sqlite3_config()] interface will return a
1795** non-zero [error code] if a discontinued or unsupported configuration option
1796** is invoked.
1797**
1798** <dl>
1799** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1800** <dd>There are no arguments to this option.  ^This option sets the
1801** [threading mode] to Single-thread.  In other words, it disables
1802** all mutexing and puts SQLite into a mode where it can only be used
1803** by a single thread.   ^If SQLite is compiled with
1804** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1805** it is not possible to change the [threading mode] from its default
1806** value of Single-thread and so [sqlite3_config()] will return
1807** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1808** configuration option.</dd>
1809**
1810** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1811** <dd>There are no arguments to this option.  ^This option sets the
1812** [threading mode] to Multi-thread.  In other words, it disables
1813** mutexing on [database connection] and [prepared statement] objects.
1814** The application is responsible for serializing access to
1815** [database connections] and [prepared statements].  But other mutexes
1816** are enabled so that SQLite will be safe to use in a multi-threaded
1817** environment as long as no two threads attempt to use the same
1818** [database connection] at the same time.  ^If SQLite is compiled with
1819** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1820** it is not possible to set the Multi-thread [threading mode] and
1821** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1822** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1823**
1824** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1825** <dd>There are no arguments to this option.  ^This option sets the
1826** [threading mode] to Serialized. In other words, this option enables
1827** all mutexes including the recursive
1828** mutexes on [database connection] and [prepared statement] objects.
1829** In this mode (which is the default when SQLite is compiled with
1830** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1831** to [database connections] and [prepared statements] so that the
1832** application is free to use the same [database connection] or the
1833** same [prepared statement] in different threads at the same time.
1834** ^If SQLite is compiled with
1835** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1836** it is not possible to set the Serialized [threading mode] and
1837** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1838** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1839**
1840** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1841** <dd> ^(This option takes a single argument which is a pointer to an
1842** instance of the [sqlite3_mem_methods] structure.  The argument specifies
1843** alternative low-level memory allocation routines to be used in place of
1844** the memory allocation routines built into SQLite.)^ ^SQLite makes
1845** its own private copy of the content of the [sqlite3_mem_methods] structure
1846** before the [sqlite3_config()] call returns.</dd>
1847**
1848** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1849** <dd> ^(This option takes a single argument which is a pointer to an
1850** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
1851** structure is filled with the currently defined memory allocation routines.)^
1852** This option can be used to overload the default memory allocation
1853** routines with a wrapper that simulations memory allocation failure or
1854** tracks memory usage, for example. </dd>
1855**
1856** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1857** <dd> ^This option takes single argument of type int, interpreted as a
1858** boolean, which enables or disables the collection of memory allocation
1859** statistics. ^(When memory allocation statistics are disabled, the
1860** following SQLite interfaces become non-operational:
1861**   <ul>
1862**   <li> [sqlite3_memory_used()]
1863**   <li> [sqlite3_memory_highwater()]
1864**   <li> [sqlite3_soft_heap_limit64()]
1865**   <li> [sqlite3_status()]
1866**   </ul>)^
1867** ^Memory allocation statistics are enabled by default unless SQLite is
1868** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1869** allocation statistics are disabled by default.
1870** </dd>
1871**
1872** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1873** <dd> ^This option specifies a static memory buffer that SQLite can use for
1874** scratch memory.  There are three arguments:  A pointer an 8-byte
1875** aligned memory buffer from which the scratch allocations will be
1876** drawn, the size of each scratch allocation (sz),
1877** and the maximum number of scratch allocations (N).  The sz
1878** argument must be a multiple of 16.
1879** The first argument must be a pointer to an 8-byte aligned buffer
1880** of at least sz*N bytes of memory.
1881** ^SQLite will use no more than two scratch buffers per thread.  So
1882** N should be set to twice the expected maximum number of threads.
1883** ^SQLite will never require a scratch buffer that is more than 6
1884** times the database page size. ^If SQLite needs needs additional
1885** scratch memory beyond what is provided by this configuration option, then
1886** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1887**
1888** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1889** <dd> ^This option specifies a static memory buffer that SQLite can use for
1890** the database page cache with the default page cache implementation.
1891** This configuration should not be used if an application-define page
1892** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
1893** There are three arguments to this option: A pointer to 8-byte aligned
1894** memory, the size of each page buffer (sz), and the number of pages (N).
1895** The sz argument should be the size of the largest database page
1896** (a power of two between 512 and 32768) plus a little extra for each
1897** page header.  ^The page header size is 20 to 40 bytes depending on
1898** the host architecture.  ^It is harmless, apart from the wasted memory,
1899** to make sz a little too large.  The first
1900** argument should point to an allocation of at least sz*N bytes of memory.
1901** ^SQLite will use the memory provided by the first argument to satisfy its
1902** memory needs for the first N pages that it adds to cache.  ^If additional
1903** page cache memory is needed beyond what is provided by this option, then
1904** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1905** The pointer in the first argument must
1906** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1907** will be undefined.</dd>
1908**
1909** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1910** <dd> ^This option specifies a static memory buffer that SQLite will use
1911** for all of its dynamic memory allocation needs beyond those provided
1912** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1913** There are three arguments: An 8-byte aligned pointer to the memory,
1914** the number of bytes in the memory buffer, and the minimum allocation size.
1915** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1916** to using its default memory allocator (the system malloc() implementation),
1917** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
1918** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1919** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1920** allocator is engaged to handle all of SQLites memory allocation needs.
1921** The first pointer (the memory pointer) must be aligned to an 8-byte
1922** boundary or subsequent behavior of SQLite will be undefined.
1923** The minimum allocation size is capped at 2^12. Reasonable values
1924** for the minimum allocation size are 2^5 through 2^8.</dd>
1925**
1926** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1927** <dd> ^(This option takes a single argument which is a pointer to an
1928** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
1929** alternative low-level mutex routines to be used in place
1930** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
1931** content of the [sqlite3_mutex_methods] structure before the call to
1932** [sqlite3_config()] returns. ^If SQLite is compiled with
1933** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1934** the entire mutexing subsystem is omitted from the build and hence calls to
1935** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1936** return [SQLITE_ERROR].</dd>
1937**
1938** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1939** <dd> ^(This option takes a single argument which is a pointer to an
1940** instance of the [sqlite3_mutex_methods] structure.  The
1941** [sqlite3_mutex_methods]
1942** structure is filled with the currently defined mutex routines.)^
1943** This option can be used to overload the default mutex allocation
1944** routines with a wrapper used to track mutex usage for performance
1945** profiling or testing, for example.   ^If SQLite is compiled with
1946** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1947** the entire mutexing subsystem is omitted from the build and hence calls to
1948** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1949** return [SQLITE_ERROR].</dd>
1950**
1951** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1952** <dd> ^(This option takes two arguments that determine the default
1953** memory allocation for the lookaside memory allocator on each
1954** [database connection].  The first argument is the
1955** size of each lookaside buffer slot and the second is the number of
1956** slots allocated to each database connection.)^  ^(This option sets the
1957** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1958** verb to [sqlite3_db_config()] can be used to change the lookaside
1959** configuration on individual connections.)^ </dd>
1960**
1961** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt>
1962** <dd> ^(This option takes a single argument which is a pointer to
1963** an [sqlite3_pcache_methods] object.  This object specifies the interface
1964** to a custom page cache implementation.)^  ^SQLite makes a copy of the
1965** object and uses it for page cache memory allocations.</dd>
1966**
1967** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt>
1968** <dd> ^(This option takes a single argument which is a pointer to an
1969** [sqlite3_pcache_methods] object.  SQLite copies of the current
1970** page cache implementation into that object.)^ </dd>
1971**
1972** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1973** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1974** function with a call signature of void(*)(void*,int,const char*),
1975** and a pointer to void. ^If the function pointer is not NULL, it is
1976** invoked by [sqlite3_log()] to process each logging event.  ^If the
1977** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1978** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1979** passed through as the first parameter to the application-defined logger
1980** function whenever that function is invoked.  ^The second parameter to
1981** the logger function is a copy of the first parameter to the corresponding
1982** [sqlite3_log()] call and is intended to be a [result code] or an
1983** [extended result code].  ^The third parameter passed to the logger is
1984** log message after formatting via [sqlite3_snprintf()].
1985** The SQLite logging interface is not reentrant; the logger function
1986** supplied by the application must not invoke any SQLite interface.
1987** In a multi-threaded application, the application-defined logger
1988** function must be threadsafe. </dd>
1989**
1990** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1991** <dd> This option takes a single argument of type int. If non-zero, then
1992** URI handling is globally enabled. If the parameter is zero, then URI handling
1993** is globally disabled. If URI handling is globally enabled, all filenames
1994** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1995** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1996** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1997** connection is opened. If it is globally disabled, filenames are
1998** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1999** database connection is opened. By default, URI handling is globally
2000** disabled. The default value may be changed by compiling with the
2001** [SQLITE_USE_URI] symbol defined.
2002** </dl>
2003*/
2004#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
2005#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
2006#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
2007#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
2008#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
2009#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
2010#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
2011#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
2012#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
2013#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
2014#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
2015/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2016#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
2017#define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
2018#define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */
2019#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
2020#define SQLITE_CONFIG_URI          17  /* int */
2021
2022/*
2023** CAPI3REF: Database Connection Configuration Options
2024**
2025** These constants are the available integer configuration options that
2026** can be passed as the second argument to the [sqlite3_db_config()] interface.
2027**
2028** New configuration options may be added in future releases of SQLite.
2029** Existing configuration options might be discontinued.  Applications
2030** should check the return code from [sqlite3_db_config()] to make sure that
2031** the call worked.  ^The [sqlite3_db_config()] interface will return a
2032** non-zero [error code] if a discontinued or unsupported configuration option
2033** is invoked.
2034**
2035** <dl>
2036** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2037** <dd> ^This option takes three additional arguments that determine the
2038** [lookaside memory allocator] configuration for the [database connection].
2039** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2040** pointer to a memory buffer to use for lookaside memory.
2041** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2042** may be NULL in which case SQLite will allocate the
2043** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2044** size of each lookaside buffer slot.  ^The third argument is the number of
2045** slots.  The size of the buffer in the first argument must be greater than
2046** or equal to the product of the second and third arguments.  The buffer
2047** must be aligned to an 8-byte boundary.  ^If the second argument to
2048** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2049** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
2050** configuration for a database connection can only be changed when that
2051** connection is not currently using lookaside memory, or in other words
2052** when the "current value" returned by
2053** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2054** Any attempt to change the lookaside memory configuration when lookaside
2055** memory is in use leaves the configuration unchanged and returns
2056** [SQLITE_BUSY].)^</dd>
2057**
2058** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2059** <dd> ^This option is used to enable or disable the enforcement of
2060** [foreign key constraints].  There should be two additional arguments.
2061** The first argument is an integer which is 0 to disable FK enforcement,
2062** positive to enable FK enforcement or negative to leave FK enforcement
2063** unchanged.  The second parameter is a pointer to an integer into which
2064** is written 0 or 1 to indicate whether FK enforcement is off or on
2065** following this call.  The second parameter may be a NULL pointer, in
2066** which case the FK enforcement setting is not reported back. </dd>
2067**
2068** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2069** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2070** There should be two additional arguments.
2071** The first argument is an integer which is 0 to disable triggers,
2072** positive to enable triggers or negative to leave the setting unchanged.
2073** The second parameter is a pointer to an integer into which
2074** is written 0 or 1 to indicate whether triggers are disabled or enabled
2075** following this call.  The second parameter may be a NULL pointer, in
2076** which case the trigger setting is not reported back. </dd>
2077**
2078** </dl>
2079*/
2080#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
2081#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
2082#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
2083
2084
2085/*
2086** CAPI3REF: Enable Or Disable Extended Result Codes
2087**
2088** ^The sqlite3_extended_result_codes() routine enables or disables the
2089** [extended result codes] feature of SQLite. ^The extended result
2090** codes are disabled by default for historical compatibility.
2091*/
2092SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2093
2094/*
2095** CAPI3REF: Last Insert Rowid
2096**
2097** ^Each entry in an SQLite table has a unique 64-bit signed
2098** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2099** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2100** names are not also used by explicitly declared columns. ^If
2101** the table has a column of type [INTEGER PRIMARY KEY] then that column
2102** is another alias for the rowid.
2103**
2104** ^This routine returns the [rowid] of the most recent
2105** successful [INSERT] into the database from the [database connection]
2106** in the first argument.  ^As of SQLite version 3.7.7, this routines
2107** records the last insert rowid of both ordinary tables and [virtual tables].
2108** ^If no successful [INSERT]s
2109** have ever occurred on that database connection, zero is returned.
2110**
2111** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
2112** method, then this routine will return the [rowid] of the inserted
2113** row as long as the trigger or virtual table method is running.
2114** But once the trigger or virtual table method ends, the value returned
2115** by this routine reverts to what it was before the trigger or virtual
2116** table method began.)^
2117**
2118** ^An [INSERT] that fails due to a constraint violation is not a
2119** successful [INSERT] and does not change the value returned by this
2120** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2121** and INSERT OR ABORT make no changes to the return value of this
2122** routine when their insertion fails.  ^(When INSERT OR REPLACE
2123** encounters a constraint violation, it does not fail.  The
2124** INSERT continues to completion after deleting rows that caused
2125** the constraint problem so INSERT OR REPLACE will always change
2126** the return value of this interface.)^
2127**
2128** ^For the purposes of this routine, an [INSERT] is considered to
2129** be successful even if it is subsequently rolled back.
2130**
2131** This function is accessible to SQL statements via the
2132** [last_insert_rowid() SQL function].
2133**
2134** If a separate thread performs a new [INSERT] on the same
2135** database connection while the [sqlite3_last_insert_rowid()]
2136** function is running and thus changes the last insert [rowid],
2137** then the value returned by [sqlite3_last_insert_rowid()] is
2138** unpredictable and might not equal either the old or the new
2139** last insert [rowid].
2140*/
2141SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2142
2143/*
2144** CAPI3REF: Count The Number Of Rows Modified
2145**
2146** ^This function returns the number of database rows that were changed
2147** or inserted or deleted by the most recently completed SQL statement
2148** on the [database connection] specified by the first parameter.
2149** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
2150** or [DELETE] statement are counted.  Auxiliary changes caused by
2151** triggers or [foreign key actions] are not counted.)^ Use the
2152** [sqlite3_total_changes()] function to find the total number of changes
2153** including changes caused by triggers and foreign key actions.
2154**
2155** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
2156** are not counted.  Only real table changes are counted.
2157**
2158** ^(A "row change" is a change to a single row of a single table
2159** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
2160** are changed as side effects of [REPLACE] constraint resolution,
2161** rollback, ABORT processing, [DROP TABLE], or by any other
2162** mechanisms do not count as direct row changes.)^
2163**
2164** A "trigger context" is a scope of execution that begins and
2165** ends with the script of a [CREATE TRIGGER | trigger].
2166** Most SQL statements are
2167** evaluated outside of any trigger.  This is the "top level"
2168** trigger context.  If a trigger fires from the top level, a
2169** new trigger context is entered for the duration of that one
2170** trigger.  Subtriggers create subcontexts for their duration.
2171**
2172** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
2173** not create a new trigger context.
2174**
2175** ^This function returns the number of direct row changes in the
2176** most recent INSERT, UPDATE, or DELETE statement within the same
2177** trigger context.
2178**
2179** ^Thus, when called from the top level, this function returns the
2180** number of changes in the most recent INSERT, UPDATE, or DELETE
2181** that also occurred at the top level.  ^(Within the body of a trigger,
2182** the sqlite3_changes() interface can be called to find the number of
2183** changes in the most recently completed INSERT, UPDATE, or DELETE
2184** statement within the body of the same trigger.
2185** However, the number returned does not include changes
2186** caused by subtriggers since those have their own context.)^
2187**
2188** See also the [sqlite3_total_changes()] interface, the
2189** [count_changes pragma], and the [changes() SQL function].
2190**
2191** If a separate thread makes changes on the same database connection
2192** while [sqlite3_changes()] is running then the value returned
2193** is unpredictable and not meaningful.
2194*/
2195SQLITE_API int sqlite3_changes(sqlite3*);
2196
2197/*
2198** CAPI3REF: Total Number Of Rows Modified
2199**
2200** ^This function returns the number of row changes caused by [INSERT],
2201** [UPDATE] or [DELETE] statements since the [database connection] was opened.
2202** ^(The count returned by sqlite3_total_changes() includes all changes
2203** from all [CREATE TRIGGER | trigger] contexts and changes made by
2204** [foreign key actions]. However,
2205** the count does not include changes used to implement [REPLACE] constraints,
2206** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
2207** count does not include rows of views that fire an [INSTEAD OF trigger],
2208** though if the INSTEAD OF trigger makes changes of its own, those changes
2209** are counted.)^
2210** ^The sqlite3_total_changes() function counts the changes as soon as
2211** the statement that makes them is completed (when the statement handle
2212** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
2213**
2214** See also the [sqlite3_changes()] interface, the
2215** [count_changes pragma], and the [total_changes() SQL function].
2216**
2217** If a separate thread makes changes on the same database connection
2218** while [sqlite3_total_changes()] is running then the value
2219** returned is unpredictable and not meaningful.
2220*/
2221SQLITE_API int sqlite3_total_changes(sqlite3*);
2222
2223/*
2224** CAPI3REF: Interrupt A Long-Running Query
2225**
2226** ^This function causes any pending database operation to abort and
2227** return at its earliest opportunity. This routine is typically
2228** called in response to a user action such as pressing "Cancel"
2229** or Ctrl-C where the user wants a long query operation to halt
2230** immediately.
2231**
2232** ^It is safe to call this routine from a thread different from the
2233** thread that is currently running the database operation.  But it
2234** is not safe to call this routine with a [database connection] that
2235** is closed or might close before sqlite3_interrupt() returns.
2236**
2237** ^If an SQL operation is very nearly finished at the time when
2238** sqlite3_interrupt() is called, then it might not have an opportunity
2239** to be interrupted and might continue to completion.
2240**
2241** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2242** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2243** that is inside an explicit transaction, then the entire transaction
2244** will be rolled back automatically.
2245**
2246** ^The sqlite3_interrupt(D) call is in effect until all currently running
2247** SQL statements on [database connection] D complete.  ^Any new SQL statements
2248** that are started after the sqlite3_interrupt() call and before the
2249** running statements reaches zero are interrupted as if they had been
2250** running prior to the sqlite3_interrupt() call.  ^New SQL statements
2251** that are started after the running statement count reaches zero are
2252** not effected by the sqlite3_interrupt().
2253** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2254** SQL statements is a no-op and has no effect on SQL statements
2255** that are started after the sqlite3_interrupt() call returns.
2256**
2257** If the database connection closes while [sqlite3_interrupt()]
2258** is running then bad things will likely happen.
2259*/
2260SQLITE_API void sqlite3_interrupt(sqlite3*);
2261
2262/*
2263** CAPI3REF: Determine If An SQL Statement Is Complete
2264**
2265** These routines are useful during command-line input to determine if the
2266** currently entered text seems to form a complete SQL statement or
2267** if additional input is needed before sending the text into
2268** SQLite for parsing.  ^These routines return 1 if the input string
2269** appears to be a complete SQL statement.  ^A statement is judged to be
2270** complete if it ends with a semicolon token and is not a prefix of a
2271** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
2272** string literals or quoted identifier names or comments are not
2273** independent tokens (they are part of the token in which they are
2274** embedded) and thus do not count as a statement terminator.  ^Whitespace
2275** and comments that follow the final semicolon are ignored.
2276**
2277** ^These routines return 0 if the statement is incomplete.  ^If a
2278** memory allocation fails, then SQLITE_NOMEM is returned.
2279**
2280** ^These routines do not parse the SQL statements thus
2281** will not detect syntactically incorrect SQL.
2282**
2283** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2284** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2285** automatically by sqlite3_complete16().  If that initialization fails,
2286** then the return value from sqlite3_complete16() will be non-zero
2287** regardless of whether or not the input SQL is complete.)^
2288**
2289** The input to [sqlite3_complete()] must be a zero-terminated
2290** UTF-8 string.
2291**
2292** The input to [sqlite3_complete16()] must be a zero-terminated
2293** UTF-16 string in native byte order.
2294*/
2295SQLITE_API int sqlite3_complete(const char *sql);
2296SQLITE_API int sqlite3_complete16(const void *sql);
2297
2298/*
2299** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2300**
2301** ^This routine sets a callback function that might be invoked whenever
2302** an attempt is made to open a database table that another thread
2303** or process has locked.
2304**
2305** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
2306** is returned immediately upon encountering the lock.  ^If the busy callback
2307** is not NULL, then the callback might be invoked with two arguments.
2308**
2309** ^The first argument to the busy handler is a copy of the void* pointer which
2310** is the third argument to sqlite3_busy_handler().  ^The second argument to
2311** the busy handler callback is the number of times that the busy handler has
2312** been invoked for this locking event.  ^If the
2313** busy callback returns 0, then no additional attempts are made to
2314** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
2315** ^If the callback returns non-zero, then another attempt
2316** is made to open the database for reading and the cycle repeats.
2317**
2318** The presence of a busy handler does not guarantee that it will be invoked
2319** when there is lock contention. ^If SQLite determines that invoking the busy
2320** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2321** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
2322** Consider a scenario where one process is holding a read lock that
2323** it is trying to promote to a reserved lock and
2324** a second process is holding a reserved lock that it is trying
2325** to promote to an exclusive lock.  The first process cannot proceed
2326** because it is blocked by the second and the second process cannot
2327** proceed because it is blocked by the first.  If both processes
2328** invoke the busy handlers, neither will make any progress.  Therefore,
2329** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2330** will induce the first process to release its read lock and allow
2331** the second process to proceed.
2332**
2333** ^The default busy callback is NULL.
2334**
2335** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
2336** when SQLite is in the middle of a large transaction where all the
2337** changes will not fit into the in-memory cache.  SQLite will
2338** already hold a RESERVED lock on the database file, but it needs
2339** to promote this lock to EXCLUSIVE so that it can spill cache
2340** pages into the database file without harm to concurrent
2341** readers.  ^If it is unable to promote the lock, then the in-memory
2342** cache will be left in an inconsistent state and so the error
2343** code is promoted from the relatively benign [SQLITE_BUSY] to
2344** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
2345** forces an automatic rollback of the changes.  See the
2346** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
2347** CorruptionFollowingBusyError</a> wiki page for a discussion of why
2348** this is important.
2349**
2350** ^(There can only be a single busy handler defined for each
2351** [database connection].  Setting a new busy handler clears any
2352** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
2353** will also set or clear the busy handler.
2354**
2355** The busy callback should not take any actions which modify the
2356** database connection that invoked the busy handler.  Any such actions
2357** result in undefined behavior.
2358**
2359** A busy handler must not close the database connection
2360** or [prepared statement] that invoked the busy handler.
2361*/
2362SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2363
2364/*
2365** CAPI3REF: Set A Busy Timeout
2366**
2367** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2368** for a specified amount of time when a table is locked.  ^The handler
2369** will sleep multiple times until at least "ms" milliseconds of sleeping
2370** have accumulated.  ^After at least "ms" milliseconds of sleeping,
2371** the handler returns 0 which causes [sqlite3_step()] to return
2372** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
2373**
2374** ^Calling this routine with an argument less than or equal to zero
2375** turns off all busy handlers.
2376**
2377** ^(There can only be a single busy handler for a particular
2378** [database connection] any any given moment.  If another busy handler
2379** was defined  (using [sqlite3_busy_handler()]) prior to calling
2380** this routine, that other busy handler is cleared.)^
2381*/
2382SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2383
2384/*
2385** CAPI3REF: Convenience Routines For Running Queries
2386**
2387** This is a legacy interface that is preserved for backwards compatibility.
2388** Use of this interface is not recommended.
2389**
2390** Definition: A <b>result table</b> is memory data structure created by the
2391** [sqlite3_get_table()] interface.  A result table records the
2392** complete query results from one or more queries.
2393**
2394** The table conceptually has a number of rows and columns.  But
2395** these numbers are not part of the result table itself.  These
2396** numbers are obtained separately.  Let N be the number of rows
2397** and M be the number of columns.
2398**
2399** A result table is an array of pointers to zero-terminated UTF-8 strings.
2400** There are (N+1)*M elements in the array.  The first M pointers point
2401** to zero-terminated strings that  contain the names of the columns.
2402** The remaining entries all point to query results.  NULL values result
2403** in NULL pointers.  All other values are in their UTF-8 zero-terminated
2404** string representation as returned by [sqlite3_column_text()].
2405**
2406** A result table might consist of one or more memory allocations.
2407** It is not safe to pass a result table directly to [sqlite3_free()].
2408** A result table should be deallocated using [sqlite3_free_table()].
2409**
2410** ^(As an example of the result table format, suppose a query result
2411** is as follows:
2412**
2413** <blockquote><pre>
2414**        Name        | Age
2415**        -----------------------
2416**        Alice       | 43
2417**        Bob         | 28
2418**        Cindy       | 21
2419** </pre></blockquote>
2420**
2421** There are two column (M==2) and three rows (N==3).  Thus the
2422** result table has 8 entries.  Suppose the result table is stored
2423** in an array names azResult.  Then azResult holds this content:
2424**
2425** <blockquote><pre>
2426**        azResult&#91;0] = "Name";
2427**        azResult&#91;1] = "Age";
2428**        azResult&#91;2] = "Alice";
2429**        azResult&#91;3] = "43";
2430**        azResult&#91;4] = "Bob";
2431**        azResult&#91;5] = "28";
2432**        azResult&#91;6] = "Cindy";
2433**        azResult&#91;7] = "21";
2434** </pre></blockquote>)^
2435**
2436** ^The sqlite3_get_table() function evaluates one or more
2437** semicolon-separated SQL statements in the zero-terminated UTF-8
2438** string of its 2nd parameter and returns a result table to the
2439** pointer given in its 3rd parameter.
2440**
2441** After the application has finished with the result from sqlite3_get_table(),
2442** it must pass the result table pointer to sqlite3_free_table() in order to
2443** release the memory that was malloced.  Because of the way the
2444** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2445** function must not try to call [sqlite3_free()] directly.  Only
2446** [sqlite3_free_table()] is able to release the memory properly and safely.
2447**
2448** The sqlite3_get_table() interface is implemented as a wrapper around
2449** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
2450** to any internal data structures of SQLite.  It uses only the public
2451** interface defined here.  As a consequence, errors that occur in the
2452** wrapper layer outside of the internal [sqlite3_exec()] call are not
2453** reflected in subsequent calls to [sqlite3_errcode()] or
2454** [sqlite3_errmsg()].
2455*/
2456SQLITE_API int sqlite3_get_table(
2457  sqlite3 *db,          /* An open database */
2458  const char *zSql,     /* SQL to be evaluated */
2459  char ***pazResult,    /* Results of the query */
2460  int *pnRow,           /* Number of result rows written here */
2461  int *pnColumn,        /* Number of result columns written here */
2462  char **pzErrmsg       /* Error msg written here */
2463);
2464SQLITE_API void sqlite3_free_table(char **result);
2465
2466/*
2467** CAPI3REF: Formatted String Printing Functions
2468**
2469** These routines are work-alikes of the "printf()" family of functions
2470** from the standard C library.
2471**
2472** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2473** results into memory obtained from [sqlite3_malloc()].
2474** The strings returned by these two routines should be
2475** released by [sqlite3_free()].  ^Both routines return a
2476** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2477** memory to hold the resulting string.
2478**
2479** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2480** the standard C library.  The result is written into the
2481** buffer supplied as the second parameter whose size is given by
2482** the first parameter. Note that the order of the
2483** first two parameters is reversed from snprintf().)^  This is an
2484** historical accident that cannot be fixed without breaking
2485** backwards compatibility.  ^(Note also that sqlite3_snprintf()
2486** returns a pointer to its buffer instead of the number of
2487** characters actually written into the buffer.)^  We admit that
2488** the number of characters written would be a more useful return
2489** value but we cannot change the implementation of sqlite3_snprintf()
2490** now without breaking compatibility.
2491**
2492** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2493** guarantees that the buffer is always zero-terminated.  ^The first
2494** parameter "n" is the total size of the buffer, including space for
2495** the zero terminator.  So the longest string that can be completely
2496** written will be n-1 characters.
2497**
2498** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2499**
2500** These routines all implement some additional formatting
2501** options that are useful for constructing SQL statements.
2502** All of the usual printf() formatting options apply.  In addition, there
2503** is are "%q", "%Q", and "%z" options.
2504**
2505** ^(The %q option works like %s in that it substitutes a null-terminated
2506** string from the argument list.  But %q also doubles every '\'' character.
2507** %q is designed for use inside a string literal.)^  By doubling each '\''
2508** character it escapes that character and allows it to be inserted into
2509** the string.
2510**
2511** For example, assume the string variable zText contains text as follows:
2512**
2513** <blockquote><pre>
2514**  char *zText = "It's a happy day!";
2515** </pre></blockquote>
2516**
2517** One can use this text in an SQL statement as follows:
2518**
2519** <blockquote><pre>
2520**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2521**  sqlite3_exec(db, zSQL, 0, 0, 0);
2522**  sqlite3_free(zSQL);
2523** </pre></blockquote>
2524**
2525** Because the %q format string is used, the '\'' character in zText
2526** is escaped and the SQL generated is as follows:
2527**
2528** <blockquote><pre>
2529**  INSERT INTO table1 VALUES('It''s a happy day!')
2530** </pre></blockquote>
2531**
2532** This is correct.  Had we used %s instead of %q, the generated SQL
2533** would have looked like this:
2534**
2535** <blockquote><pre>
2536**  INSERT INTO table1 VALUES('It's a happy day!');
2537** </pre></blockquote>
2538**
2539** This second example is an SQL syntax error.  As a general rule you should
2540** always use %q instead of %s when inserting text into a string literal.
2541**
2542** ^(The %Q option works like %q except it also adds single quotes around
2543** the outside of the total string.  Additionally, if the parameter in the
2544** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2545** single quotes).)^  So, for example, one could say:
2546**
2547** <blockquote><pre>
2548**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2549**  sqlite3_exec(db, zSQL, 0, 0, 0);
2550**  sqlite3_free(zSQL);
2551** </pre></blockquote>
2552**
2553** The code above will render a correct SQL statement in the zSQL
2554** variable even if the zText variable is a NULL pointer.
2555**
2556** ^(The "%z" formatting option works like "%s" but with the
2557** addition that after the string has been read and copied into
2558** the result, [sqlite3_free()] is called on the input string.)^
2559*/
2560SQLITE_API char *sqlite3_mprintf(const char*,...);
2561SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2562SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2563SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2564
2565/*
2566** CAPI3REF: Memory Allocation Subsystem
2567**
2568** The SQLite core uses these three routines for all of its own
2569** internal memory allocation needs. "Core" in the previous sentence
2570** does not include operating-system specific VFS implementation.  The
2571** Windows VFS uses native malloc() and free() for some operations.
2572**
2573** ^The sqlite3_malloc() routine returns a pointer to a block
2574** of memory at least N bytes in length, where N is the parameter.
2575** ^If sqlite3_malloc() is unable to obtain sufficient free
2576** memory, it returns a NULL pointer.  ^If the parameter N to
2577** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2578** a NULL pointer.
2579**
2580** ^Calling sqlite3_free() with a pointer previously returned
2581** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2582** that it might be reused.  ^The sqlite3_free() routine is
2583** a no-op if is called with a NULL pointer.  Passing a NULL pointer
2584** to sqlite3_free() is harmless.  After being freed, memory
2585** should neither be read nor written.  Even reading previously freed
2586** memory might result in a segmentation fault or other severe error.
2587** Memory corruption, a segmentation fault, or other severe error
2588** might result if sqlite3_free() is called with a non-NULL pointer that
2589** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2590**
2591** ^(The sqlite3_realloc() interface attempts to resize a
2592** prior memory allocation to be at least N bytes, where N is the
2593** second parameter.  The memory allocation to be resized is the first
2594** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2595** is a NULL pointer then its behavior is identical to calling
2596** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2597** ^If the second parameter to sqlite3_realloc() is zero or
2598** negative then the behavior is exactly the same as calling
2599** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2600** ^sqlite3_realloc() returns a pointer to a memory allocation
2601** of at least N bytes in size or NULL if sufficient memory is unavailable.
2602** ^If M is the size of the prior allocation, then min(N,M) bytes
2603** of the prior allocation are copied into the beginning of buffer returned
2604** by sqlite3_realloc() and the prior allocation is freed.
2605** ^If sqlite3_realloc() returns NULL, then the prior allocation
2606** is not freed.
2607**
2608** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2609** is always aligned to at least an 8 byte boundary, or to a
2610** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2611** option is used.
2612**
2613** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2614** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2615** implementation of these routines to be omitted.  That capability
2616** is no longer provided.  Only built-in memory allocators can be used.
2617**
2618** The Windows OS interface layer calls
2619** the system malloc() and free() directly when converting
2620** filenames between the UTF-8 encoding used by SQLite
2621** and whatever filename encoding is used by the particular Windows
2622** installation.  Memory allocation errors are detected, but
2623** they are reported back as [SQLITE_CANTOPEN] or
2624** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2625**
2626** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2627** must be either NULL or else pointers obtained from a prior
2628** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2629** not yet been released.
2630**
2631** The application must not read or write any part of
2632** a block of memory after it has been released using
2633** [sqlite3_free()] or [sqlite3_realloc()].
2634*/
2635SQLITE_API void *sqlite3_malloc(int);
2636SQLITE_API void *sqlite3_realloc(void*, int);
2637SQLITE_API void sqlite3_free(void*);
2638
2639/*
2640** CAPI3REF: Memory Allocator Statistics
2641**
2642** SQLite provides these two interfaces for reporting on the status
2643** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2644** routines, which form the built-in memory allocation subsystem.
2645**
2646** ^The [sqlite3_memory_used()] routine returns the number of bytes
2647** of memory currently outstanding (malloced but not freed).
2648** ^The [sqlite3_memory_highwater()] routine returns the maximum
2649** value of [sqlite3_memory_used()] since the high-water mark
2650** was last reset.  ^The values returned by [sqlite3_memory_used()] and
2651** [sqlite3_memory_highwater()] include any overhead
2652** added by SQLite in its implementation of [sqlite3_malloc()],
2653** but not overhead added by the any underlying system library
2654** routines that [sqlite3_malloc()] may call.
2655**
2656** ^The memory high-water mark is reset to the current value of
2657** [sqlite3_memory_used()] if and only if the parameter to
2658** [sqlite3_memory_highwater()] is true.  ^The value returned
2659** by [sqlite3_memory_highwater(1)] is the high-water mark
2660** prior to the reset.
2661*/
2662SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2663SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2664
2665/*
2666** CAPI3REF: Pseudo-Random Number Generator
2667**
2668** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2669** select random [ROWID | ROWIDs] when inserting new records into a table that
2670** already uses the largest possible [ROWID].  The PRNG is also used for
2671** the build-in random() and randomblob() SQL functions.  This interface allows
2672** applications to access the same PRNG for other purposes.
2673**
2674** ^A call to this routine stores N bytes of randomness into buffer P.
2675**
2676** ^The first time this routine is invoked (either internally or by
2677** the application) the PRNG is seeded using randomness obtained
2678** from the xRandomness method of the default [sqlite3_vfs] object.
2679** ^On all subsequent invocations, the pseudo-randomness is generated
2680** internally and without recourse to the [sqlite3_vfs] xRandomness
2681** method.
2682*/
2683SQLITE_API void sqlite3_randomness(int N, void *P);
2684
2685/*
2686** CAPI3REF: Compile-Time Authorization Callbacks
2687**
2688** ^This routine registers an authorizer callback with a particular
2689** [database connection], supplied in the first argument.
2690** ^The authorizer callback is invoked as SQL statements are being compiled
2691** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2692** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
2693** points during the compilation process, as logic is being created
2694** to perform various actions, the authorizer callback is invoked to
2695** see if those actions are allowed.  ^The authorizer callback should
2696** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2697** specific action but allow the SQL statement to continue to be
2698** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2699** rejected with an error.  ^If the authorizer callback returns
2700** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2701** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2702** the authorizer will fail with an error message.
2703**
2704** When the callback returns [SQLITE_OK], that means the operation
2705** requested is ok.  ^When the callback returns [SQLITE_DENY], the
2706** [sqlite3_prepare_v2()] or equivalent call that triggered the
2707** authorizer will fail with an error message explaining that
2708** access is denied.
2709**
2710** ^The first parameter to the authorizer callback is a copy of the third
2711** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2712** to the callback is an integer [SQLITE_COPY | action code] that specifies
2713** the particular action to be authorized. ^The third through sixth parameters
2714** to the callback are zero-terminated strings that contain additional
2715** details about the action to be authorized.
2716**
2717** ^If the action code is [SQLITE_READ]
2718** and the callback returns [SQLITE_IGNORE] then the
2719** [prepared statement] statement is constructed to substitute
2720** a NULL value in place of the table column that would have
2721** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
2722** return can be used to deny an untrusted user access to individual
2723** columns of a table.
2724** ^If the action code is [SQLITE_DELETE] and the callback returns
2725** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2726** [truncate optimization] is disabled and all rows are deleted individually.
2727**
2728** An authorizer is used when [sqlite3_prepare | preparing]
2729** SQL statements from an untrusted source, to ensure that the SQL statements
2730** do not try to access data they are not allowed to see, or that they do not
2731** try to execute malicious statements that damage the database.  For
2732** example, an application may allow a user to enter arbitrary
2733** SQL queries for evaluation by a database.  But the application does
2734** not want the user to be able to make arbitrary changes to the
2735** database.  An authorizer could then be put in place while the
2736** user-entered SQL is being [sqlite3_prepare | prepared] that
2737** disallows everything except [SELECT] statements.
2738**
2739** Applications that need to process SQL from untrusted sources
2740** might also consider lowering resource limits using [sqlite3_limit()]
2741** and limiting database size using the [max_page_count] [PRAGMA]
2742** in addition to using an authorizer.
2743**
2744** ^(Only a single authorizer can be in place on a database connection
2745** at a time.  Each call to sqlite3_set_authorizer overrides the
2746** previous call.)^  ^Disable the authorizer by installing a NULL callback.
2747** The authorizer is disabled by default.
2748**
2749** The authorizer callback must not do anything that will modify
2750** the database connection that invoked the authorizer callback.
2751** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2752** database connections for the meaning of "modify" in this paragraph.
2753**
2754** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2755** statement might be re-prepared during [sqlite3_step()] due to a
2756** schema change.  Hence, the application should ensure that the
2757** correct authorizer callback remains in place during the [sqlite3_step()].
2758**
2759** ^Note that the authorizer callback is invoked only during
2760** [sqlite3_prepare()] or its variants.  Authorization is not
2761** performed during statement evaluation in [sqlite3_step()], unless
2762** as stated in the previous paragraph, sqlite3_step() invokes
2763** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2764*/
2765SQLITE_API int sqlite3_set_authorizer(
2766  sqlite3*,
2767  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2768  void *pUserData
2769);
2770
2771/*
2772** CAPI3REF: Authorizer Return Codes
2773**
2774** The [sqlite3_set_authorizer | authorizer callback function] must
2775** return either [SQLITE_OK] or one of these two constants in order
2776** to signal SQLite whether or not the action is permitted.  See the
2777** [sqlite3_set_authorizer | authorizer documentation] for additional
2778** information.
2779**
2780** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2781** from the [sqlite3_vtab_on_conflict()] interface.
2782*/
2783#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
2784#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
2785
2786/*
2787** CAPI3REF: Authorizer Action Codes
2788**
2789** The [sqlite3_set_authorizer()] interface registers a callback function
2790** that is invoked to authorize certain SQL statement actions.  The
2791** second parameter to the callback is an integer code that specifies
2792** what action is being authorized.  These are the integer action codes that
2793** the authorizer callback may be passed.
2794**
2795** These action code values signify what kind of operation is to be
2796** authorized.  The 3rd and 4th parameters to the authorization
2797** callback function will be parameters or NULL depending on which of these
2798** codes is used as the second parameter.  ^(The 5th parameter to the
2799** authorizer callback is the name of the database ("main", "temp",
2800** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
2801** is the name of the inner-most trigger or view that is responsible for
2802** the access attempt or NULL if this access attempt is directly from
2803** top-level SQL code.
2804*/
2805/******************************************* 3rd ************ 4th ***********/
2806#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
2807#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
2808#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
2809#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
2810#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
2811#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
2812#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
2813#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
2814#define SQLITE_DELETE                9   /* Table Name      NULL            */
2815#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
2816#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
2817#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
2818#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
2819#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
2820#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
2821#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
2822#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
2823#define SQLITE_INSERT               18   /* Table Name      NULL            */
2824#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
2825#define SQLITE_READ                 20   /* Table Name      Column Name     */
2826#define SQLITE_SELECT               21   /* NULL            NULL            */
2827#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
2828#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
2829#define SQLITE_ATTACH               24   /* Filename        NULL            */
2830#define SQLITE_DETACH               25   /* Database Name   NULL            */
2831#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
2832#define SQLITE_REINDEX              27   /* Index Name      NULL            */
2833#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
2834#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
2835#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
2836#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
2837#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
2838#define SQLITE_COPY                  0   /* No longer used */
2839
2840/*
2841** CAPI3REF: Tracing And Profiling Functions
2842**
2843** These routines register callback functions that can be used for
2844** tracing and profiling the execution of SQL statements.
2845**
2846** ^The callback function registered by sqlite3_trace() is invoked at
2847** various times when an SQL statement is being run by [sqlite3_step()].
2848** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2849** SQL statement text as the statement first begins executing.
2850** ^(Additional sqlite3_trace() callbacks might occur
2851** as each triggered subprogram is entered.  The callbacks for triggers
2852** contain a UTF-8 SQL comment that identifies the trigger.)^
2853**
2854** ^The callback function registered by sqlite3_profile() is invoked
2855** as each SQL statement finishes.  ^The profile callback contains
2856** the original statement text and an estimate of wall-clock time
2857** of how long that statement took to run.  ^The profile callback
2858** time is in units of nanoseconds, however the current implementation
2859** is only capable of millisecond resolution so the six least significant
2860** digits in the time are meaningless.  Future versions of SQLite
2861** might provide greater resolution on the profiler callback.  The
2862** sqlite3_profile() function is considered experimental and is
2863** subject to change in future versions of SQLite.
2864*/
2865SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2866SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2867   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2868
2869/*
2870** CAPI3REF: Query Progress Callbacks
2871**
2872** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2873** function X to be invoked periodically during long running calls to
2874** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2875** database connection D.  An example use for this
2876** interface is to keep a GUI updated during a large query.
2877**
2878** ^The parameter P is passed through as the only parameter to the
2879** callback function X.  ^The parameter N is the number of
2880** [virtual machine instructions] that are evaluated between successive
2881** invocations of the callback X.
2882**
2883** ^Only a single progress handler may be defined at one time per
2884** [database connection]; setting a new progress handler cancels the
2885** old one.  ^Setting parameter X to NULL disables the progress handler.
2886** ^The progress handler is also disabled by setting N to a value less
2887** than 1.
2888**
2889** ^If the progress callback returns non-zero, the operation is
2890** interrupted.  This feature can be used to implement a
2891** "Cancel" button on a GUI progress dialog box.
2892**
2893** The progress handler callback must not do anything that will modify
2894** the database connection that invoked the progress handler.
2895** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2896** database connections for the meaning of "modify" in this paragraph.
2897**
2898*/
2899SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2900
2901/*
2902** CAPI3REF: Opening A New Database Connection
2903**
2904** ^These routines open an SQLite database file as specified by the
2905** filename argument. ^The filename argument is interpreted as UTF-8 for
2906** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2907** order for sqlite3_open16(). ^(A [database connection] handle is usually
2908** returned in *ppDb, even if an error occurs.  The only exception is that
2909** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2910** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2911** object.)^ ^(If the database is opened (and/or created) successfully, then
2912** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
2913** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2914** an English language description of the error following a failure of any
2915** of the sqlite3_open() routines.
2916**
2917** ^The default encoding for the database will be UTF-8 if
2918** sqlite3_open() or sqlite3_open_v2() is called and
2919** UTF-16 in the native byte order if sqlite3_open16() is used.
2920**
2921** Whether or not an error occurs when it is opened, resources
2922** associated with the [database connection] handle should be released by
2923** passing it to [sqlite3_close()] when it is no longer required.
2924**
2925** The sqlite3_open_v2() interface works like sqlite3_open()
2926** except that it accepts two additional parameters for additional control
2927** over the new database connection.  ^(The flags parameter to
2928** sqlite3_open_v2() can take one of
2929** the following three values, optionally combined with the
2930** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2931** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2932**
2933** <dl>
2934** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2935** <dd>The database is opened in read-only mode.  If the database does not
2936** already exist, an error is returned.</dd>)^
2937**
2938** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2939** <dd>The database is opened for reading and writing if possible, or reading
2940** only if the file is write protected by the operating system.  In either
2941** case the database must already exist, otherwise an error is returned.</dd>)^
2942**
2943** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2944** <dd>The database is opened for reading and writing, and is created if
2945** it does not already exist. This is the behavior that is always used for
2946** sqlite3_open() and sqlite3_open16().</dd>)^
2947** </dl>
2948**
2949** If the 3rd parameter to sqlite3_open_v2() is not one of the
2950** combinations shown above optionally combined with other
2951** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2952** then the behavior is undefined.
2953**
2954** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2955** opens in the multi-thread [threading mode] as long as the single-thread
2956** mode has not been set at compile-time or start-time.  ^If the
2957** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2958** in the serialized [threading mode] unless single-thread was
2959** previously selected at compile-time or start-time.
2960** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2961** eligible to use [shared cache mode], regardless of whether or not shared
2962** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
2963** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2964** participate in [shared cache mode] even if it is enabled.
2965**
2966** ^The fourth parameter to sqlite3_open_v2() is the name of the
2967** [sqlite3_vfs] object that defines the operating system interface that
2968** the new database connection should use.  ^If the fourth parameter is
2969** a NULL pointer then the default [sqlite3_vfs] object is used.
2970**
2971** ^If the filename is ":memory:", then a private, temporary in-memory database
2972** is created for the connection.  ^This in-memory database will vanish when
2973** the database connection is closed.  Future versions of SQLite might
2974** make use of additional special filenames that begin with the ":" character.
2975** It is recommended that when a database filename actually does begin with
2976** a ":" character you should prefix the filename with a pathname such as
2977** "./" to avoid ambiguity.
2978**
2979** ^If the filename is an empty string, then a private, temporary
2980** on-disk database will be created.  ^This private database will be
2981** automatically deleted as soon as the database connection is closed.
2982**
2983** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2984**
2985** ^If [URI filename] interpretation is enabled, and the filename argument
2986** begins with "file:", then the filename is interpreted as a URI. ^URI
2987** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2988** set in the fourth argument to sqlite3_open_v2(), or if it has
2989** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2990** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2991** As of SQLite version 3.7.7, URI filename interpretation is turned off
2992** by default, but future releases of SQLite might enable URI filename
2993** interpretation by default.  See "[URI filenames]" for additional
2994** information.
2995**
2996** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2997** authority, then it must be either an empty string or the string
2998** "localhost". ^If the authority is not an empty string or "localhost", an
2999** error is returned to the caller. ^The fragment component of a URI, if
3000** present, is ignored.
3001**
3002** ^SQLite uses the path component of the URI as the name of the disk file
3003** which contains the database. ^If the path begins with a '/' character,
3004** then it is interpreted as an absolute path. ^If the path does not begin
3005** with a '/' (meaning that the authority section is omitted from the URI)
3006** then the path is interpreted as a relative path.
3007** ^On windows, the first component of an absolute path
3008** is a drive specification (e.g. "C:").
3009**
3010** [[core URI query parameters]]
3011** The query component of a URI may contain parameters that are interpreted
3012** either by SQLite itself, or by a [VFS | custom VFS implementation].
3013** SQLite interprets the following three query parameters:
3014**
3015** <ul>
3016**   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3017**     a VFS object that provides the operating system interface that should
3018**     be used to access the database file on disk. ^If this option is set to
3019**     an empty string the default VFS object is used. ^Specifying an unknown
3020**     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3021**     present, then the VFS specified by the option takes precedence over
3022**     the value passed as the fourth parameter to sqlite3_open_v2().
3023**
3024**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
3025**     "rwc". Attempting to set it to any other value is an error)^.
3026**     ^If "ro" is specified, then the database is opened for read-only
3027**     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3028**     third argument to sqlite3_prepare_v2(). ^If the mode option is set to
3029**     "rw", then the database is opened for read-write (but not create)
3030**     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3031**     been set. ^Value "rwc" is equivalent to setting both
3032**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is
3033**     used, it is an error to specify a value for the mode parameter that is
3034**     less restrictive than that specified by the flags passed as the third
3035**     parameter.
3036**
3037**   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3038**     "private". ^Setting it to "shared" is equivalent to setting the
3039**     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3040**     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3041**     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3042**     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3043**     a URI filename, its value overrides any behaviour requested by setting
3044**     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3045** </ul>
3046**
3047** ^Specifying an unknown parameter in the query component of a URI is not an
3048** error.  Future versions of SQLite might understand additional query
3049** parameters.  See "[query parameters with special meaning to SQLite]" for
3050** additional information.
3051**
3052** [[URI filename examples]] <h3>URI filename examples</h3>
3053**
3054** <table border="1" align=center cellpadding=5>
3055** <tr><th> URI filenames <th> Results
3056** <tr><td> file:data.db <td>
3057**          Open the file "data.db" in the current directory.
3058** <tr><td> file:/home/fred/data.db<br>
3059**          file:///home/fred/data.db <br>
3060**          file://localhost/home/fred/data.db <br> <td>
3061**          Open the database file "/home/fred/data.db".
3062** <tr><td> file://darkstar/home/fred/data.db <td>
3063**          An error. "darkstar" is not a recognized authority.
3064** <tr><td style="white-space:nowrap">
3065**          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3066**     <td> Windows only: Open the file "data.db" on fred's desktop on drive
3067**          C:. Note that the %20 escaping in this example is not strictly
3068**          necessary - space characters can be used literally
3069**          in URI filenames.
3070** <tr><td> file:data.db?mode=ro&cache=private <td>
3071**          Open file "data.db" in the current directory for read-only access.
3072**          Regardless of whether or not shared-cache mode is enabled by
3073**          default, use a private cache.
3074** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
3075**          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
3076** <tr><td> file:data.db?mode=readonly <td>
3077**          An error. "readonly" is not a valid option for the "mode" parameter.
3078** </table>
3079**
3080** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3081** query components of a URI. A hexadecimal escape sequence consists of a
3082** percent sign - "%" - followed by exactly two hexadecimal digits
3083** specifying an octet value. ^Before the path or query components of a
3084** URI filename are interpreted, they are encoded using UTF-8 and all
3085** hexadecimal escape sequences replaced by a single byte containing the
3086** corresponding octet. If this process generates an invalid UTF-8 encoding,
3087** the results are undefined.
3088**
3089** <b>Note to Windows users:</b>  The encoding used for the filename argument
3090** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3091** codepage is currently defined.  Filenames containing international
3092** characters must be converted to UTF-8 prior to passing them into
3093** sqlite3_open() or sqlite3_open_v2().
3094*/
3095SQLITE_API int sqlite3_open(
3096  const char *filename,   /* Database filename (UTF-8) */
3097  sqlite3 **ppDb          /* OUT: SQLite db handle */
3098);
3099SQLITE_API int sqlite3_open16(
3100  const void *filename,   /* Database filename (UTF-16) */
3101  sqlite3 **ppDb          /* OUT: SQLite db handle */
3102);
3103SQLITE_API int sqlite3_open_v2(
3104  const char *filename,   /* Database filename (UTF-8) */
3105  sqlite3 **ppDb,         /* OUT: SQLite db handle */
3106  int flags,              /* Flags */
3107  const char *zVfs        /* Name of VFS module to use */
3108);
3109
3110/*
3111** CAPI3REF: Obtain Values For URI Parameters
3112**
3113** This is a utility routine, useful to VFS implementations, that checks
3114** to see if a database file was a URI that contained a specific query
3115** parameter, and if so obtains the value of the query parameter.
3116**
3117** The zFilename argument is the filename pointer passed into the xOpen()
3118** method of a VFS implementation.  The zParam argument is the name of the
3119** query parameter we seek.  This routine returns the value of the zParam
3120** parameter if it exists.  If the parameter does not exist, this routine
3121** returns a NULL pointer.
3122**
3123** If the zFilename argument to this function is not a pointer that SQLite
3124** passed into the xOpen VFS method, then the behavior of this routine
3125** is undefined and probably undesirable.
3126*/
3127SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3128
3129
3130/*
3131** CAPI3REF: Error Codes And Messages
3132**
3133** ^The sqlite3_errcode() interface returns the numeric [result code] or
3134** [extended result code] for the most recent failed sqlite3_* API call
3135** associated with a [database connection]. If a prior API call failed
3136** but the most recent API call succeeded, the return value from
3137** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
3138** interface is the same except that it always returns the
3139** [extended result code] even when extended result codes are
3140** disabled.
3141**
3142** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3143** text that describes the error, as either UTF-8 or UTF-16 respectively.
3144** ^(Memory to hold the error message string is managed internally.
3145** The application does not need to worry about freeing the result.
3146** However, the error string might be overwritten or deallocated by
3147** subsequent calls to other SQLite interface functions.)^
3148**
3149** When the serialized [threading mode] is in use, it might be the
3150** case that a second error occurs on a separate thread in between
3151** the time of the first error and the call to these interfaces.
3152** When that happens, the second error will be reported since these
3153** interfaces always report the most recent result.  To avoid
3154** this, each thread can obtain exclusive use of the [database connection] D
3155** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3156** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3157** all calls to the interfaces listed here are completed.
3158**
3159** If an interface fails with SQLITE_MISUSE, that means the interface
3160** was invoked incorrectly by the application.  In that case, the
3161** error code and message may or may not be set.
3162*/
3163SQLITE_API int sqlite3_errcode(sqlite3 *db);
3164SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3165SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3166SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3167
3168/*
3169** CAPI3REF: SQL Statement Object
3170** KEYWORDS: {prepared statement} {prepared statements}
3171**
3172** An instance of this object represents a single SQL statement.
3173** This object is variously known as a "prepared statement" or a
3174** "compiled SQL statement" or simply as a "statement".
3175**
3176** The life of a statement object goes something like this:
3177**
3178** <ol>
3179** <li> Create the object using [sqlite3_prepare_v2()] or a related
3180**      function.
3181** <li> Bind values to [host parameters] using the sqlite3_bind_*()
3182**      interfaces.
3183** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3184** <li> Reset the statement using [sqlite3_reset()] then go back
3185**      to step 2.  Do this zero or more times.
3186** <li> Destroy the object using [sqlite3_finalize()].
3187** </ol>
3188**
3189** Refer to documentation on individual methods above for additional
3190** information.
3191*/
3192typedef struct sqlite3_stmt sqlite3_stmt;
3193
3194/*
3195** CAPI3REF: Run-time Limits
3196**
3197** ^(This interface allows the size of various constructs to be limited
3198** on a connection by connection basis.  The first parameter is the
3199** [database connection] whose limit is to be set or queried.  The
3200** second parameter is one of the [limit categories] that define a
3201** class of constructs to be size limited.  The third parameter is the
3202** new limit for that construct.)^
3203**
3204** ^If the new limit is a negative number, the limit is unchanged.
3205** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3206** [limits | hard upper bound]
3207** set at compile-time by a C preprocessor macro called
3208** [limits | SQLITE_MAX_<i>NAME</i>].
3209** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3210** ^Attempts to increase a limit above its hard upper bound are
3211** silently truncated to the hard upper bound.
3212**
3213** ^Regardless of whether or not the limit was changed, the
3214** [sqlite3_limit()] interface returns the prior value of the limit.
3215** ^Hence, to find the current value of a limit without changing it,
3216** simply invoke this interface with the third parameter set to -1.
3217**
3218** Run-time limits are intended for use in applications that manage
3219** both their own internal database and also databases that are controlled
3220** by untrusted external sources.  An example application might be a
3221** web browser that has its own databases for storing history and
3222** separate databases controlled by JavaScript applications downloaded
3223** off the Internet.  The internal databases can be given the
3224** large, default limits.  Databases managed by external sources can
3225** be given much smaller limits designed to prevent a denial of service
3226** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
3227** interface to further control untrusted SQL.  The size of the database
3228** created by an untrusted script can be contained using the
3229** [max_page_count] [PRAGMA].
3230**
3231** New run-time limit categories may be added in future releases.
3232*/
3233SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3234
3235/*
3236** CAPI3REF: Run-Time Limit Categories
3237** KEYWORDS: {limit category} {*limit categories}
3238**
3239** These constants define various performance limits
3240** that can be lowered at run-time using [sqlite3_limit()].
3241** The synopsis of the meanings of the various limits is shown below.
3242** Additional information is available at [limits | Limits in SQLite].
3243**
3244** <dl>
3245** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3246** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3247**
3248** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3249** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3250**
3251** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3252** <dd>The maximum number of columns in a table definition or in the
3253** result set of a [SELECT] or the maximum number of columns in an index
3254** or in an ORDER BY or GROUP BY clause.</dd>)^
3255**
3256** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3257** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3258**
3259** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3260** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3261**
3262** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3263** <dd>The maximum number of instructions in a virtual machine program
3264** used to implement an SQL statement.  This limit is not currently
3265** enforced, though that might be added in some future release of
3266** SQLite.</dd>)^
3267**
3268** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3269** <dd>The maximum number of arguments on a function.</dd>)^
3270**
3271** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3272** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3273**
3274** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3275** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3276** <dd>The maximum length of the pattern argument to the [LIKE] or
3277** [GLOB] operators.</dd>)^
3278**
3279** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3280** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3281** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3282**
3283** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3284** <dd>The maximum depth of recursion for triggers.</dd>)^
3285** </dl>
3286*/
3287#define SQLITE_LIMIT_LENGTH                    0
3288#define SQLITE_LIMIT_SQL_LENGTH                1
3289#define SQLITE_LIMIT_COLUMN                    2
3290#define SQLITE_LIMIT_EXPR_DEPTH                3
3291#define SQLITE_LIMIT_COMPOUND_SELECT           4
3292#define SQLITE_LIMIT_VDBE_OP                   5
3293#define SQLITE_LIMIT_FUNCTION_ARG              6
3294#define SQLITE_LIMIT_ATTACHED                  7
3295#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
3296#define SQLITE_LIMIT_VARIABLE_NUMBER           9
3297#define SQLITE_LIMIT_TRIGGER_DEPTH            10
3298
3299/*
3300** CAPI3REF: Compiling An SQL Statement
3301** KEYWORDS: {SQL statement compiler}
3302**
3303** To execute an SQL query, it must first be compiled into a byte-code
3304** program using one of these routines.
3305**
3306** The first argument, "db", is a [database connection] obtained from a
3307** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3308** [sqlite3_open16()].  The database connection must not have been closed.
3309**
3310** The second argument, "zSql", is the statement to be compiled, encoded
3311** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
3312** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3313** use UTF-16.
3314**
3315** ^If the nByte argument is less than zero, then zSql is read up to the
3316** first zero terminator. ^If nByte is non-negative, then it is the maximum
3317** number of  bytes read from zSql.  ^When nByte is non-negative, the
3318** zSql string ends at either the first '\000' or '\u0000' character or
3319** the nByte-th byte, whichever comes first. If the caller knows
3320** that the supplied string is nul-terminated, then there is a small
3321** performance advantage to be gained by passing an nByte parameter that
3322** is equal to the number of bytes in the input string <i>including</i>
3323** the nul-terminator bytes.
3324**
3325** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3326** past the end of the first SQL statement in zSql.  These routines only
3327** compile the first statement in zSql, so *pzTail is left pointing to
3328** what remains uncompiled.
3329**
3330** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3331** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
3332** to NULL.  ^If the input text contains no SQL (if the input is an empty
3333** string or a comment) then *ppStmt is set to NULL.
3334** The calling procedure is responsible for deleting the compiled
3335** SQL statement using [sqlite3_finalize()] after it has finished with it.
3336** ppStmt may not be NULL.
3337**
3338** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3339** otherwise an [error code] is returned.
3340**
3341** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3342** recommended for all new programs. The two older interfaces are retained
3343** for backwards compatibility, but their use is discouraged.
3344** ^In the "v2" interfaces, the prepared statement
3345** that is returned (the [sqlite3_stmt] object) contains a copy of the
3346** original SQL text. This causes the [sqlite3_step()] interface to
3347** behave differently in three ways:
3348**
3349** <ol>
3350** <li>
3351** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3352** always used to do, [sqlite3_step()] will automatically recompile the SQL
3353** statement and try to run it again.
3354** </li>
3355**
3356** <li>
3357** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3358** [error codes] or [extended error codes].  ^The legacy behavior was that
3359** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3360** and the application would have to make a second call to [sqlite3_reset()]
3361** in order to find the underlying cause of the problem. With the "v2" prepare
3362** interfaces, the underlying reason for the error is returned immediately.
3363** </li>
3364**
3365** <li>
3366** ^If the specific value bound to [parameter | host parameter] in the
3367** WHERE clause might influence the choice of query plan for a statement,
3368** then the statement will be automatically recompiled, as if there had been
3369** a schema change, on the first  [sqlite3_step()] call following any change
3370** to the [sqlite3_bind_text | bindings] of that [parameter].
3371** ^The specific value of WHERE-clause [parameter] might influence the
3372** choice of query plan if the parameter is the left-hand side of a [LIKE]
3373** or [GLOB] operator or if the parameter is compared to an indexed column
3374** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled.
3375** the
3376** </li>
3377** </ol>
3378*/
3379SQLITE_API int sqlite3_prepare(
3380  sqlite3 *db,            /* Database handle */
3381  const char *zSql,       /* SQL statement, UTF-8 encoded */
3382  int nByte,              /* Maximum length of zSql in bytes. */
3383  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3384  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3385);
3386SQLITE_API int sqlite3_prepare_v2(
3387  sqlite3 *db,            /* Database handle */
3388  const char *zSql,       /* SQL statement, UTF-8 encoded */
3389  int nByte,              /* Maximum length of zSql in bytes. */
3390  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3391  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3392);
3393SQLITE_API int sqlite3_prepare16(
3394  sqlite3 *db,            /* Database handle */
3395  const void *zSql,       /* SQL statement, UTF-16 encoded */
3396  int nByte,              /* Maximum length of zSql in bytes. */
3397  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3398  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3399);
3400SQLITE_API int sqlite3_prepare16_v2(
3401  sqlite3 *db,            /* Database handle */
3402  const void *zSql,       /* SQL statement, UTF-16 encoded */
3403  int nByte,              /* Maximum length of zSql in bytes. */
3404  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3405  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3406);
3407
3408/*
3409** CAPI3REF: Retrieving Statement SQL
3410**
3411** ^This interface can be used to retrieve a saved copy of the original
3412** SQL text used to create a [prepared statement] if that statement was
3413** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3414*/
3415SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3416
3417/*
3418** CAPI3REF: Determine If An SQL Statement Writes The Database
3419**
3420** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3421** and only if the [prepared statement] X makes no direct changes to
3422** the content of the database file.
3423**
3424** Note that [application-defined SQL functions] or
3425** [virtual tables] might change the database indirectly as a side effect.
3426** ^(For example, if an application defines a function "eval()" that
3427** calls [sqlite3_exec()], then the following SQL statement would
3428** change the database file through side-effects:
3429**
3430** <blockquote><pre>
3431**    SELECT eval('DELETE FROM t1') FROM t2;
3432** </pre></blockquote>
3433**
3434** But because the [SELECT] statement does not change the database file
3435** directly, sqlite3_stmt_readonly() would still return true.)^
3436**
3437** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3438** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3439** since the statements themselves do not actually modify the database but
3440** rather they control the timing of when other statements modify the
3441** database.  ^The [ATTACH] and [DETACH] statements also cause
3442** sqlite3_stmt_readonly() to return true since, while those statements
3443** change the configuration of a database connection, they do not make
3444** changes to the content of the database files on disk.
3445*/
3446SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3447
3448/*
3449** CAPI3REF: Dynamically Typed Value Object
3450** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3451**
3452** SQLite uses the sqlite3_value object to represent all values
3453** that can be stored in a database table. SQLite uses dynamic typing
3454** for the values it stores.  ^Values stored in sqlite3_value objects
3455** can be integers, floating point values, strings, BLOBs, or NULL.
3456**
3457** An sqlite3_value object may be either "protected" or "unprotected".
3458** Some interfaces require a protected sqlite3_value.  Other interfaces
3459** will accept either a protected or an unprotected sqlite3_value.
3460** Every interface that accepts sqlite3_value arguments specifies
3461** whether or not it requires a protected sqlite3_value.
3462**
3463** The terms "protected" and "unprotected" refer to whether or not
3464** a mutex is held.  An internal mutex is held for a protected
3465** sqlite3_value object but no mutex is held for an unprotected
3466** sqlite3_value object.  If SQLite is compiled to be single-threaded
3467** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3468** or if SQLite is run in one of reduced mutex modes
3469** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3470** then there is no distinction between protected and unprotected
3471** sqlite3_value objects and they can be used interchangeably.  However,
3472** for maximum code portability it is recommended that applications
3473** still make the distinction between protected and unprotected
3474** sqlite3_value objects even when not strictly required.
3475**
3476** ^The sqlite3_value objects that are passed as parameters into the
3477** implementation of [application-defined SQL functions] are protected.
3478** ^The sqlite3_value object returned by
3479** [sqlite3_column_value()] is unprotected.
3480** Unprotected sqlite3_value objects may only be used with
3481** [sqlite3_result_value()] and [sqlite3_bind_value()].
3482** The [sqlite3_value_blob | sqlite3_value_type()] family of
3483** interfaces require protected sqlite3_value objects.
3484*/
3485typedef struct Mem sqlite3_value;
3486
3487/*
3488** CAPI3REF: SQL Function Context Object
3489**
3490** The context in which an SQL function executes is stored in an
3491** sqlite3_context object.  ^A pointer to an sqlite3_context object
3492** is always first parameter to [application-defined SQL functions].
3493** The application-defined SQL function implementation will pass this
3494** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3495** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3496** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3497** and/or [sqlite3_set_auxdata()].
3498*/
3499typedef struct sqlite3_context sqlite3_context;
3500
3501/*
3502** CAPI3REF: Binding Values To Prepared Statements
3503** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3504** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3505**
3506** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3507** literals may be replaced by a [parameter] that matches one of following
3508** templates:
3509**
3510** <ul>
3511** <li>  ?
3512** <li>  ?NNN
3513** <li>  :VVV
3514** <li>  @VVV
3515** <li>  $VVV
3516** </ul>
3517**
3518** In the templates above, NNN represents an integer literal,
3519** and VVV represents an alphanumeric identifier.)^  ^The values of these
3520** parameters (also called "host parameter names" or "SQL parameters")
3521** can be set using the sqlite3_bind_*() routines defined here.
3522**
3523** ^The first argument to the sqlite3_bind_*() routines is always
3524** a pointer to the [sqlite3_stmt] object returned from
3525** [sqlite3_prepare_v2()] or its variants.
3526**
3527** ^The second argument is the index of the SQL parameter to be set.
3528** ^The leftmost SQL parameter has an index of 1.  ^When the same named
3529** SQL parameter is used more than once, second and subsequent
3530** occurrences have the same index as the first occurrence.
3531** ^The index for named parameters can be looked up using the
3532** [sqlite3_bind_parameter_index()] API if desired.  ^The index
3533** for "?NNN" parameters is the value of NNN.
3534** ^The NNN value must be between 1 and the [sqlite3_limit()]
3535** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3536**
3537** ^The third argument is the value to bind to the parameter.
3538**
3539** ^(In those routines that have a fourth argument, its value is the
3540** number of bytes in the parameter.  To be clear: the value is the
3541** number of <u>bytes</u> in the value, not the number of characters.)^
3542** ^If the fourth parameter is negative, the length of the string is
3543** the number of bytes up to the first zero terminator.
3544**
3545** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3546** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3547** string after SQLite has finished with it.  ^The destructor is called
3548** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3549** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3550** ^If the fifth argument is
3551** the special value [SQLITE_STATIC], then SQLite assumes that the
3552** information is in static, unmanaged space and does not need to be freed.
3553** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3554** SQLite makes its own private copy of the data immediately, before
3555** the sqlite3_bind_*() routine returns.
3556**
3557** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3558** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
3559** (just an integer to hold its size) while it is being processed.
3560** Zeroblobs are intended to serve as placeholders for BLOBs whose
3561** content is later written using
3562** [sqlite3_blob_open | incremental BLOB I/O] routines.
3563** ^A negative value for the zeroblob results in a zero-length BLOB.
3564**
3565** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3566** for the [prepared statement] or with a prepared statement for which
3567** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3568** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
3569** routine is passed a [prepared statement] that has been finalized, the
3570** result is undefined and probably harmful.
3571**
3572** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3573** ^Unbound parameters are interpreted as NULL.
3574**
3575** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3576** [error code] if anything goes wrong.
3577** ^[SQLITE_RANGE] is returned if the parameter
3578** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
3579**
3580** See also: [sqlite3_bind_parameter_count()],
3581** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3582*/
3583SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3584SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3585SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3586SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3587SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3588SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3589SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3590SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3591SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3592
3593/*
3594** CAPI3REF: Number Of SQL Parameters
3595**
3596** ^This routine can be used to find the number of [SQL parameters]
3597** in a [prepared statement].  SQL parameters are tokens of the
3598** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3599** placeholders for values that are [sqlite3_bind_blob | bound]
3600** to the parameters at a later time.
3601**
3602** ^(This routine actually returns the index of the largest (rightmost)
3603** parameter. For all forms except ?NNN, this will correspond to the
3604** number of unique parameters.  If parameters of the ?NNN form are used,
3605** there may be gaps in the list.)^
3606**
3607** See also: [sqlite3_bind_blob|sqlite3_bind()],
3608** [sqlite3_bind_parameter_name()], and
3609** [sqlite3_bind_parameter_index()].
3610*/
3611SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3612
3613/*
3614** CAPI3REF: Name Of A Host Parameter
3615**
3616** ^The sqlite3_bind_parameter_name(P,N) interface returns
3617** the name of the N-th [SQL parameter] in the [prepared statement] P.
3618** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3619** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3620** respectively.
3621** In other words, the initial ":" or "$" or "@" or "?"
3622** is included as part of the name.)^
3623** ^Parameters of the form "?" without a following integer have no name
3624** and are referred to as "nameless" or "anonymous parameters".
3625**
3626** ^The first host parameter has an index of 1, not 0.
3627**
3628** ^If the value N is out of range or if the N-th parameter is
3629** nameless, then NULL is returned.  ^The returned string is
3630** always in UTF-8 encoding even if the named parameter was
3631** originally specified as UTF-16 in [sqlite3_prepare16()] or
3632** [sqlite3_prepare16_v2()].
3633**
3634** See also: [sqlite3_bind_blob|sqlite3_bind()],
3635** [sqlite3_bind_parameter_count()], and
3636** [sqlite3_bind_parameter_index()].
3637*/
3638SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3639
3640/*
3641** CAPI3REF: Index Of A Parameter With A Given Name
3642**
3643** ^Return the index of an SQL parameter given its name.  ^The
3644** index value returned is suitable for use as the second
3645** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
3646** is returned if no matching parameter is found.  ^The parameter
3647** name must be given in UTF-8 even if the original statement
3648** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3649**
3650** See also: [sqlite3_bind_blob|sqlite3_bind()],
3651** [sqlite3_bind_parameter_count()], and
3652** [sqlite3_bind_parameter_index()].
3653*/
3654SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3655
3656/*
3657** CAPI3REF: Reset All Bindings On A Prepared Statement
3658**
3659** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3660** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3661** ^Use this routine to reset all host parameters to NULL.
3662*/
3663SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3664
3665/*
3666** CAPI3REF: Number Of Columns In A Result Set
3667**
3668** ^Return the number of columns in the result set returned by the
3669** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3670** statement that does not return data (for example an [UPDATE]).
3671**
3672** See also: [sqlite3_data_count()]
3673*/
3674SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3675
3676/*
3677** CAPI3REF: Column Names In A Result Set
3678**
3679** ^These routines return the name assigned to a particular column
3680** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
3681** interface returns a pointer to a zero-terminated UTF-8 string
3682** and sqlite3_column_name16() returns a pointer to a zero-terminated
3683** UTF-16 string.  ^The first parameter is the [prepared statement]
3684** that implements the [SELECT] statement. ^The second parameter is the
3685** column number.  ^The leftmost column is number 0.
3686**
3687** ^The returned string pointer is valid until either the [prepared statement]
3688** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3689** reprepared by the first call to [sqlite3_step()] for a particular run
3690** or until the next call to
3691** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3692**
3693** ^If sqlite3_malloc() fails during the processing of either routine
3694** (for example during a conversion from UTF-8 to UTF-16) then a
3695** NULL pointer is returned.
3696**
3697** ^The name of a result column is the value of the "AS" clause for
3698** that column, if there is an AS clause.  If there is no AS clause
3699** then the name of the column is unspecified and may change from
3700** one release of SQLite to the next.
3701*/
3702SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3703SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3704
3705/*
3706** CAPI3REF: Source Of Data In A Query Result
3707**
3708** ^These routines provide a means to determine the database, table, and
3709** table column that is the origin of a particular result column in
3710** [SELECT] statement.
3711** ^The name of the database or table or column can be returned as
3712** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
3713** the database name, the _table_ routines return the table name, and
3714** the origin_ routines return the column name.
3715** ^The returned string is valid until the [prepared statement] is destroyed
3716** using [sqlite3_finalize()] or until the statement is automatically
3717** reprepared by the first call to [sqlite3_step()] for a particular run
3718** or until the same information is requested
3719** again in a different encoding.
3720**
3721** ^The names returned are the original un-aliased names of the
3722** database, table, and column.
3723**
3724** ^The first argument to these interfaces is a [prepared statement].
3725** ^These functions return information about the Nth result column returned by
3726** the statement, where N is the second function argument.
3727** ^The left-most column is column 0 for these routines.
3728**
3729** ^If the Nth column returned by the statement is an expression or
3730** subquery and is not a column value, then all of these functions return
3731** NULL.  ^These routine might also return NULL if a memory allocation error
3732** occurs.  ^Otherwise, they return the name of the attached database, table,
3733** or column that query result column was extracted from.
3734**
3735** ^As with all other SQLite APIs, those whose names end with "16" return
3736** UTF-16 encoded strings and the other functions return UTF-8.
3737**
3738** ^These APIs are only available if the library was compiled with the
3739** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3740**
3741** If two or more threads call one or more of these routines against the same
3742** prepared statement and column at the same time then the results are
3743** undefined.
3744**
3745** If two or more threads call one or more
3746** [sqlite3_column_database_name | column metadata interfaces]
3747** for the same [prepared statement] and result column
3748** at the same time then the results are undefined.
3749*/
3750SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3751SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3752SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3753SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3754SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3755SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3756
3757/*
3758** CAPI3REF: Declared Datatype Of A Query Result
3759**
3760** ^(The first parameter is a [prepared statement].
3761** If this statement is a [SELECT] statement and the Nth column of the
3762** returned result set of that [SELECT] is a table column (not an
3763** expression or subquery) then the declared type of the table
3764** column is returned.)^  ^If the Nth column of the result set is an
3765** expression or subquery, then a NULL pointer is returned.
3766** ^The returned string is always UTF-8 encoded.
3767**
3768** ^(For example, given the database schema:
3769**
3770** CREATE TABLE t1(c1 VARIANT);
3771**
3772** and the following statement to be compiled:
3773**
3774** SELECT c1 + 1, c1 FROM t1;
3775**
3776** this routine would return the string "VARIANT" for the second result
3777** column (i==1), and a NULL pointer for the first result column (i==0).)^
3778**
3779** ^SQLite uses dynamic run-time typing.  ^So just because a column
3780** is declared to contain a particular type does not mean that the
3781** data stored in that column is of the declared type.  SQLite is
3782** strongly typed, but the typing is dynamic not static.  ^Type
3783** is associated with individual values, not with the containers
3784** used to hold those values.
3785*/
3786SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3787SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3788
3789/*
3790** CAPI3REF: Evaluate An SQL Statement
3791**
3792** After a [prepared statement] has been prepared using either
3793** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3794** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3795** must be called one or more times to evaluate the statement.
3796**
3797** The details of the behavior of the sqlite3_step() interface depend
3798** on whether the statement was prepared using the newer "v2" interface
3799** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3800** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
3801** new "v2" interface is recommended for new applications but the legacy
3802** interface will continue to be supported.
3803**
3804** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3805** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3806** ^With the "v2" interface, any of the other [result codes] or
3807** [extended result codes] might be returned as well.
3808**
3809** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3810** database locks it needs to do its job.  ^If the statement is a [COMMIT]
3811** or occurs outside of an explicit transaction, then you can retry the
3812** statement.  If the statement is not a [COMMIT] and occurs within an
3813** explicit transaction then you should rollback the transaction before
3814** continuing.
3815**
3816** ^[SQLITE_DONE] means that the statement has finished executing
3817** successfully.  sqlite3_step() should not be called again on this virtual
3818** machine without first calling [sqlite3_reset()] to reset the virtual
3819** machine back to its initial state.
3820**
3821** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3822** is returned each time a new row of data is ready for processing by the
3823** caller. The values may be accessed using the [column access functions].
3824** sqlite3_step() is called again to retrieve the next row of data.
3825**
3826** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3827** violation) has occurred.  sqlite3_step() should not be called again on
3828** the VM. More information may be found by calling [sqlite3_errmsg()].
3829** ^With the legacy interface, a more specific error code (for example,
3830** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3831** can be obtained by calling [sqlite3_reset()] on the
3832** [prepared statement].  ^In the "v2" interface,
3833** the more specific error code is returned directly by sqlite3_step().
3834**
3835** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3836** Perhaps it was called on a [prepared statement] that has
3837** already been [sqlite3_finalize | finalized] or on one that had
3838** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
3839** be the case that the same database connection is being used by two or
3840** more threads at the same moment in time.
3841**
3842** For all versions of SQLite up to and including 3.6.23.1, a call to
3843** [sqlite3_reset()] was required after sqlite3_step() returned anything
3844** other than [SQLITE_ROW] before any subsequent invocation of
3845** sqlite3_step().  Failure to reset the prepared statement using
3846** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3847** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
3848** calling [sqlite3_reset()] automatically in this circumstance rather
3849** than returning [SQLITE_MISUSE].  This is not considered a compatibility
3850** break because any application that ever receives an SQLITE_MISUSE error
3851** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
3852** can be used to restore the legacy behavior.
3853**
3854** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3855** API always returns a generic error code, [SQLITE_ERROR], following any
3856** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
3857** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3858** specific [error codes] that better describes the error.
3859** We admit that this is a goofy design.  The problem has been fixed
3860** with the "v2" interface.  If you prepare all of your SQL statements
3861** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3862** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3863** then the more specific [error codes] are returned directly
3864** by sqlite3_step().  The use of the "v2" interface is recommended.
3865*/
3866SQLITE_API int sqlite3_step(sqlite3_stmt*);
3867
3868/*
3869** CAPI3REF: Number of columns in a result set
3870**
3871** ^The sqlite3_data_count(P) interface returns the number of columns in the
3872** current row of the result set of [prepared statement] P.
3873** ^If prepared statement P does not have results ready to return
3874** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3875** interfaces) then sqlite3_data_count(P) returns 0.
3876** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3877**
3878** See also: [sqlite3_column_count()]
3879*/
3880SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3881
3882/*
3883** CAPI3REF: Fundamental Datatypes
3884** KEYWORDS: SQLITE_TEXT
3885**
3886** ^(Every value in SQLite has one of five fundamental datatypes:
3887**
3888** <ul>
3889** <li> 64-bit signed integer
3890** <li> 64-bit IEEE floating point number
3891** <li> string
3892** <li> BLOB
3893** <li> NULL
3894** </ul>)^
3895**
3896** These constants are codes for each of those types.
3897**
3898** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3899** for a completely different meaning.  Software that links against both
3900** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3901** SQLITE_TEXT.
3902*/
3903#define SQLITE_INTEGER  1
3904#define SQLITE_FLOAT    2
3905#define SQLITE_BLOB     4
3906#define SQLITE_NULL     5
3907#ifdef SQLITE_TEXT
3908# undef SQLITE_TEXT
3909#else
3910# define SQLITE_TEXT     3
3911#endif
3912#define SQLITE3_TEXT     3
3913
3914/*
3915** CAPI3REF: Result Values From A Query
3916** KEYWORDS: {column access functions}
3917**
3918** These routines form the "result set" interface.
3919**
3920** ^These routines return information about a single column of the current
3921** result row of a query.  ^In every case the first argument is a pointer
3922** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3923** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3924** and the second argument is the index of the column for which information
3925** should be returned. ^The leftmost column of the result set has the index 0.
3926** ^The number of columns in the result can be determined using
3927** [sqlite3_column_count()].
3928**
3929** If the SQL statement does not currently point to a valid row, or if the
3930** column index is out of range, the result is undefined.
3931** These routines may only be called when the most recent call to
3932** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3933** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3934** If any of these routines are called after [sqlite3_reset()] or
3935** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3936** something other than [SQLITE_ROW], the results are undefined.
3937** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3938** are called from a different thread while any of these routines
3939** are pending, then the results are undefined.
3940**
3941** ^The sqlite3_column_type() routine returns the
3942** [SQLITE_INTEGER | datatype code] for the initial data type
3943** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
3944** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
3945** returned by sqlite3_column_type() is only meaningful if no type
3946** conversions have occurred as described below.  After a type conversion,
3947** the value returned by sqlite3_column_type() is undefined.  Future
3948** versions of SQLite may change the behavior of sqlite3_column_type()
3949** following a type conversion.
3950**
3951** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3952** routine returns the number of bytes in that BLOB or string.
3953** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3954** the string to UTF-8 and then returns the number of bytes.
3955** ^If the result is a numeric value then sqlite3_column_bytes() uses
3956** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3957** the number of bytes in that string.
3958** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3959**
3960** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3961** routine returns the number of bytes in that BLOB or string.
3962** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3963** the string to UTF-16 and then returns the number of bytes.
3964** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3965** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3966** the number of bytes in that string.
3967** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3968**
3969** ^The values returned by [sqlite3_column_bytes()] and
3970** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3971** of the string.  ^For clarity: the values returned by
3972** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3973** bytes in the string, not the number of characters.
3974**
3975** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3976** even empty strings, are always zero terminated.  ^The return
3977** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3978**
3979** ^The object returned by [sqlite3_column_value()] is an
3980** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
3981** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3982** If the [unprotected sqlite3_value] object returned by
3983** [sqlite3_column_value()] is used in any other way, including calls
3984** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3985** or [sqlite3_value_bytes()], then the behavior is undefined.
3986**
3987** These routines attempt to convert the value where appropriate.  ^For
3988** example, if the internal representation is FLOAT and a text result
3989** is requested, [sqlite3_snprintf()] is used internally to perform the
3990** conversion automatically.  ^(The following table details the conversions
3991** that are applied:
3992**
3993** <blockquote>
3994** <table border="1">
3995** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
3996**
3997** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
3998** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
3999** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
4000** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
4001** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
4002** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
4003** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
4004** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
4005** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
4006** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
4007** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
4008** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
4009** <tr><td>  TEXT    <td>   BLOB    <td> No change
4010** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
4011** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
4012** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
4013** </table>
4014** </blockquote>)^
4015**
4016** The table above makes reference to standard C library functions atoi()
4017** and atof().  SQLite does not really use these functions.  It has its
4018** own equivalent internal routines.  The atoi() and atof() names are
4019** used in the table for brevity and because they are familiar to most
4020** C programmers.
4021**
4022** Note that when type conversions occur, pointers returned by prior
4023** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4024** sqlite3_column_text16() may be invalidated.
4025** Type conversions and pointer invalidations might occur
4026** in the following cases:
4027**
4028** <ul>
4029** <li> The initial content is a BLOB and sqlite3_column_text() or
4030**      sqlite3_column_text16() is called.  A zero-terminator might
4031**      need to be added to the string.</li>
4032** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4033**      sqlite3_column_text16() is called.  The content must be converted
4034**      to UTF-16.</li>
4035** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4036**      sqlite3_column_text() is called.  The content must be converted
4037**      to UTF-8.</li>
4038** </ul>
4039**
4040** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4041** not invalidate a prior pointer, though of course the content of the buffer
4042** that the prior pointer references will have been modified.  Other kinds
4043** of conversion are done in place when it is possible, but sometimes they
4044** are not possible and in those cases prior pointers are invalidated.
4045**
4046** The safest and easiest to remember policy is to invoke these routines
4047** in one of the following ways:
4048**
4049** <ul>
4050**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4051**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4052**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4053** </ul>
4054**
4055** In other words, you should call sqlite3_column_text(),
4056** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4057** into the desired format, then invoke sqlite3_column_bytes() or
4058** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
4059** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4060** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4061** with calls to sqlite3_column_bytes().
4062**
4063** ^The pointers returned are valid until a type conversion occurs as
4064** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4065** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
4066** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
4067** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4068** [sqlite3_free()].
4069**
4070** ^(If a memory allocation error occurs during the evaluation of any
4071** of these routines, a default value is returned.  The default value
4072** is either the integer 0, the floating point number 0.0, or a NULL
4073** pointer.  Subsequent calls to [sqlite3_errcode()] will return
4074** [SQLITE_NOMEM].)^
4075*/
4076SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4077SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4078SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4079SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4080SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4081SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4082SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4083SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4084SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4085SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4086
4087/*
4088** CAPI3REF: Destroy A Prepared Statement Object
4089**
4090** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4091** ^If the most recent evaluation of the statement encountered no errors
4092** or if the statement is never been evaluated, then sqlite3_finalize() returns
4093** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
4094** sqlite3_finalize(S) returns the appropriate [error code] or
4095** [extended error code].
4096**
4097** ^The sqlite3_finalize(S) routine can be called at any point during
4098** the life cycle of [prepared statement] S:
4099** before statement S is ever evaluated, after
4100** one or more calls to [sqlite3_reset()], or after any call
4101** to [sqlite3_step()] regardless of whether or not the statement has
4102** completed execution.
4103**
4104** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4105**
4106** The application must finalize every [prepared statement] in order to avoid
4107** resource leaks.  It is a grievous error for the application to try to use
4108** a prepared statement after it has been finalized.  Any use of a prepared
4109** statement after it has been finalized can result in undefined and
4110** undesirable behavior such as segfaults and heap corruption.
4111*/
4112SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4113
4114/*
4115** CAPI3REF: Reset A Prepared Statement Object
4116**
4117** The sqlite3_reset() function is called to reset a [prepared statement]
4118** object back to its initial state, ready to be re-executed.
4119** ^Any SQL statement variables that had values bound to them using
4120** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4121** Use [sqlite3_clear_bindings()] to reset the bindings.
4122**
4123** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4124** back to the beginning of its program.
4125**
4126** ^If the most recent call to [sqlite3_step(S)] for the
4127** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4128** or if [sqlite3_step(S)] has never before been called on S,
4129** then [sqlite3_reset(S)] returns [SQLITE_OK].
4130**
4131** ^If the most recent call to [sqlite3_step(S)] for the
4132** [prepared statement] S indicated an error, then
4133** [sqlite3_reset(S)] returns an appropriate [error code].
4134**
4135** ^The [sqlite3_reset(S)] interface does not change the values
4136** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4137*/
4138SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4139
4140/*
4141** CAPI3REF: Create Or Redefine SQL Functions
4142** KEYWORDS: {function creation routines}
4143** KEYWORDS: {application-defined SQL function}
4144** KEYWORDS: {application-defined SQL functions}
4145**
4146** ^These functions (collectively known as "function creation routines")
4147** are used to add SQL functions or aggregates or to redefine the behavior
4148** of existing SQL functions or aggregates.  The only differences between
4149** these routines are the text encoding expected for
4150** the second parameter (the name of the function being created)
4151** and the presence or absence of a destructor callback for
4152** the application data pointer.
4153**
4154** ^The first parameter is the [database connection] to which the SQL
4155** function is to be added.  ^If an application uses more than one database
4156** connection then application-defined SQL functions must be added
4157** to each database connection separately.
4158**
4159** ^The second parameter is the name of the SQL function to be created or
4160** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
4161** representation, exclusive of the zero-terminator.  ^Note that the name
4162** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4163** ^Any attempt to create a function with a longer name
4164** will result in [SQLITE_MISUSE] being returned.
4165**
4166** ^The third parameter (nArg)
4167** is the number of arguments that the SQL function or
4168** aggregate takes. ^If this parameter is -1, then the SQL function or
4169** aggregate may take any number of arguments between 0 and the limit
4170** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
4171** parameter is less than -1 or greater than 127 then the behavior is
4172** undefined.
4173**
4174** ^The fourth parameter, eTextRep, specifies what
4175** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4176** its parameters.  Every SQL function implementation must be able to work
4177** with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
4178** more efficient with one encoding than another.  ^An application may
4179** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
4180** times with the same function but with different values of eTextRep.
4181** ^When multiple implementations of the same function are available, SQLite
4182** will pick the one that involves the least amount of data conversion.
4183** If there is only a single implementation which does not care what text
4184** encoding is used, then the fourth argument should be [SQLITE_ANY].
4185**
4186** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
4187** function can gain access to this pointer using [sqlite3_user_data()].)^
4188**
4189** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4190** pointers to C-language functions that implement the SQL function or
4191** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4192** callback only; NULL pointers must be passed as the xStep and xFinal
4193** parameters. ^An aggregate SQL function requires an implementation of xStep
4194** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4195** SQL function or aggregate, pass NULL pointers for all three function
4196** callbacks.
4197**
4198** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4199** then it is destructor for the application data pointer.
4200** The destructor is invoked when the function is deleted, either by being
4201** overloaded or when the database connection closes.)^
4202** ^The destructor is also invoked if the call to
4203** sqlite3_create_function_v2() fails.
4204** ^When the destructor callback of the tenth parameter is invoked, it
4205** is passed a single argument which is a copy of the application data
4206** pointer which was the fifth parameter to sqlite3_create_function_v2().
4207**
4208** ^It is permitted to register multiple implementations of the same
4209** functions with the same name but with either differing numbers of
4210** arguments or differing preferred text encodings.  ^SQLite will use
4211** the implementation that most closely matches the way in which the
4212** SQL function is used.  ^A function implementation with a non-negative
4213** nArg parameter is a better match than a function implementation with
4214** a negative nArg.  ^A function where the preferred text encoding
4215** matches the database encoding is a better
4216** match than a function where the encoding is different.
4217** ^A function where the encoding difference is between UTF16le and UTF16be
4218** is a closer match than a function where the encoding difference is
4219** between UTF8 and UTF16.
4220**
4221** ^Built-in functions may be overloaded by new application-defined functions.
4222**
4223** ^An application-defined function is permitted to call other
4224** SQLite interfaces.  However, such calls must not
4225** close the database connection nor finalize or reset the prepared
4226** statement in which the function is running.
4227*/
4228SQLITE_API int sqlite3_create_function(
4229  sqlite3 *db,
4230  const char *zFunctionName,
4231  int nArg,
4232  int eTextRep,
4233  void *pApp,
4234  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4235  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4236  void (*xFinal)(sqlite3_context*)
4237);
4238SQLITE_API int sqlite3_create_function16(
4239  sqlite3 *db,
4240  const void *zFunctionName,
4241  int nArg,
4242  int eTextRep,
4243  void *pApp,
4244  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4245  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4246  void (*xFinal)(sqlite3_context*)
4247);
4248SQLITE_API int sqlite3_create_function_v2(
4249  sqlite3 *db,
4250  const char *zFunctionName,
4251  int nArg,
4252  int eTextRep,
4253  void *pApp,
4254  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4255  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4256  void (*xFinal)(sqlite3_context*),
4257  void(*xDestroy)(void*)
4258);
4259
4260/*
4261** CAPI3REF: Text Encodings
4262**
4263** These constant define integer codes that represent the various
4264** text encodings supported by SQLite.
4265*/
4266#define SQLITE_UTF8           1
4267#define SQLITE_UTF16LE        2
4268#define SQLITE_UTF16BE        3
4269#define SQLITE_UTF16          4    /* Use native byte order */
4270#define SQLITE_ANY            5    /* sqlite3_create_function only */
4271#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
4272
4273/*
4274** CAPI3REF: Deprecated Functions
4275** DEPRECATED
4276**
4277** These functions are [deprecated].  In order to maintain
4278** backwards compatibility with older code, these functions continue
4279** to be supported.  However, new applications should avoid
4280** the use of these functions.  To help encourage people to avoid
4281** using these functions, we are not going to tell you what they do.
4282*/
4283#ifndef SQLITE_OMIT_DEPRECATED
4284SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4285SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4286SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4287SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4288SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4289SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
4290#endif
4291
4292/*
4293** CAPI3REF: Obtaining SQL Function Parameter Values
4294**
4295** The C-language implementation of SQL functions and aggregates uses
4296** this set of interface routines to access the parameter values on
4297** the function or aggregate.
4298**
4299** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4300** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4301** define callbacks that implement the SQL functions and aggregates.
4302** The 3rd parameter to these callbacks is an array of pointers to
4303** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
4304** each parameter to the SQL function.  These routines are used to
4305** extract values from the [sqlite3_value] objects.
4306**
4307** These routines work only with [protected sqlite3_value] objects.
4308** Any attempt to use these routines on an [unprotected sqlite3_value]
4309** object results in undefined behavior.
4310**
4311** ^These routines work just like the corresponding [column access functions]
4312** except that  these routines take a single [protected sqlite3_value] object
4313** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4314**
4315** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4316** in the native byte-order of the host machine.  ^The
4317** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4318** extract UTF-16 strings as big-endian and little-endian respectively.
4319**
4320** ^(The sqlite3_value_numeric_type() interface attempts to apply
4321** numeric affinity to the value.  This means that an attempt is
4322** made to convert the value to an integer or floating point.  If
4323** such a conversion is possible without loss of information (in other
4324** words, if the value is a string that looks like a number)
4325** then the conversion is performed.  Otherwise no conversion occurs.
4326** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4327**
4328** Please pay particular attention to the fact that the pointer returned
4329** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4330** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4331** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4332** or [sqlite3_value_text16()].
4333**
4334** These routines must be called from the same thread as
4335** the SQL function that supplied the [sqlite3_value*] parameters.
4336*/
4337SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4338SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4339SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4340SQLITE_API double sqlite3_value_double(sqlite3_value*);
4341SQLITE_API int sqlite3_value_int(sqlite3_value*);
4342SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4343SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4344SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4345SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4346SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4347SQLITE_API int sqlite3_value_type(sqlite3_value*);
4348SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4349
4350/*
4351** CAPI3REF: Obtain Aggregate Function Context
4352**
4353** Implementations of aggregate SQL functions use this
4354** routine to allocate memory for storing their state.
4355**
4356** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4357** for a particular aggregate function, SQLite
4358** allocates N of memory, zeroes out that memory, and returns a pointer
4359** to the new memory. ^On second and subsequent calls to
4360** sqlite3_aggregate_context() for the same aggregate function instance,
4361** the same buffer is returned.  Sqlite3_aggregate_context() is normally
4362** called once for each invocation of the xStep callback and then one
4363** last time when the xFinal callback is invoked.  ^(When no rows match
4364** an aggregate query, the xStep() callback of the aggregate function
4365** implementation is never called and xFinal() is called exactly once.
4366** In those cases, sqlite3_aggregate_context() might be called for the
4367** first time from within xFinal().)^
4368**
4369** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
4370** less than or equal to zero or if a memory allocate error occurs.
4371**
4372** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4373** determined by the N parameter on first successful call.  Changing the
4374** value of N in subsequent call to sqlite3_aggregate_context() within
4375** the same aggregate function instance will not resize the memory
4376** allocation.)^
4377**
4378** ^SQLite automatically frees the memory allocated by
4379** sqlite3_aggregate_context() when the aggregate query concludes.
4380**
4381** The first parameter must be a copy of the
4382** [sqlite3_context | SQL function context] that is the first parameter
4383** to the xStep or xFinal callback routine that implements the aggregate
4384** function.
4385**
4386** This routine must be called from the same thread in which
4387** the aggregate SQL function is running.
4388*/
4389SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4390
4391/*
4392** CAPI3REF: User Data For Functions
4393**
4394** ^The sqlite3_user_data() interface returns a copy of
4395** the pointer that was the pUserData parameter (the 5th parameter)
4396** of the [sqlite3_create_function()]
4397** and [sqlite3_create_function16()] routines that originally
4398** registered the application defined function.
4399**
4400** This routine must be called from the same thread in which
4401** the application-defined function is running.
4402*/
4403SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4404
4405/*
4406** CAPI3REF: Database Connection For Functions
4407**
4408** ^The sqlite3_context_db_handle() interface returns a copy of
4409** the pointer to the [database connection] (the 1st parameter)
4410** of the [sqlite3_create_function()]
4411** and [sqlite3_create_function16()] routines that originally
4412** registered the application defined function.
4413*/
4414SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4415
4416/*
4417** CAPI3REF: Function Auxiliary Data
4418**
4419** The following two functions may be used by scalar SQL functions to
4420** associate metadata with argument values. If the same value is passed to
4421** multiple invocations of the same SQL function during query execution, under
4422** some circumstances the associated metadata may be preserved. This may
4423** be used, for example, to add a regular-expression matching scalar
4424** function. The compiled version of the regular expression is stored as
4425** metadata associated with the SQL value passed as the regular expression
4426** pattern.  The compiled regular expression can be reused on multiple
4427** invocations of the same function so that the original pattern string
4428** does not need to be recompiled on each invocation.
4429**
4430** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4431** associated by the sqlite3_set_auxdata() function with the Nth argument
4432** value to the application-defined function. ^If no metadata has been ever
4433** been set for the Nth argument of the function, or if the corresponding
4434** function parameter has changed since the meta-data was set,
4435** then sqlite3_get_auxdata() returns a NULL pointer.
4436**
4437** ^The sqlite3_set_auxdata() interface saves the metadata
4438** pointed to by its 3rd parameter as the metadata for the N-th
4439** argument of the application-defined function.  Subsequent
4440** calls to sqlite3_get_auxdata() might return this data, if it has
4441** not been destroyed.
4442** ^If it is not NULL, SQLite will invoke the destructor
4443** function given by the 4th parameter to sqlite3_set_auxdata() on
4444** the metadata when the corresponding function parameter changes
4445** or when the SQL statement completes, whichever comes first.
4446**
4447** SQLite is free to call the destructor and drop metadata on any
4448** parameter of any function at any time.  ^The only guarantee is that
4449** the destructor will be called before the metadata is dropped.
4450**
4451** ^(In practice, metadata is preserved between function calls for
4452** expressions that are constant at compile time. This includes literal
4453** values and [parameters].)^
4454**
4455** These routines must be called from the same thread in which
4456** the SQL function is running.
4457*/
4458SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4459SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4460
4461
4462/*
4463** CAPI3REF: Constants Defining Special Destructor Behavior
4464**
4465** These are special values for the destructor that is passed in as the
4466** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
4467** argument is SQLITE_STATIC, it means that the content pointer is constant
4468** and will never change.  It does not need to be destroyed.  ^The
4469** SQLITE_TRANSIENT value means that the content will likely change in
4470** the near future and that SQLite should make its own private copy of
4471** the content before returning.
4472**
4473** The typedef is necessary to work around problems in certain
4474** C++ compilers.  See ticket #2191.
4475*/
4476typedef void (*sqlite3_destructor_type)(void*);
4477#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
4478#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
4479
4480/*
4481** CAPI3REF: Setting The Result Of An SQL Function
4482**
4483** These routines are used by the xFunc or xFinal callbacks that
4484** implement SQL functions and aggregates.  See
4485** [sqlite3_create_function()] and [sqlite3_create_function16()]
4486** for additional information.
4487**
4488** These functions work very much like the [parameter binding] family of
4489** functions used to bind values to host parameters in prepared statements.
4490** Refer to the [SQL parameter] documentation for additional information.
4491**
4492** ^The sqlite3_result_blob() interface sets the result from
4493** an application-defined function to be the BLOB whose content is pointed
4494** to by the second parameter and which is N bytes long where N is the
4495** third parameter.
4496**
4497** ^The sqlite3_result_zeroblob() interfaces set the result of
4498** the application-defined function to be a BLOB containing all zero
4499** bytes and N bytes in size, where N is the value of the 2nd parameter.
4500**
4501** ^The sqlite3_result_double() interface sets the result from
4502** an application-defined function to be a floating point value specified
4503** by its 2nd argument.
4504**
4505** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4506** cause the implemented SQL function to throw an exception.
4507** ^SQLite uses the string pointed to by the
4508** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4509** as the text of an error message.  ^SQLite interprets the error
4510** message string from sqlite3_result_error() as UTF-8. ^SQLite
4511** interprets the string from sqlite3_result_error16() as UTF-16 in native
4512** byte order.  ^If the third parameter to sqlite3_result_error()
4513** or sqlite3_result_error16() is negative then SQLite takes as the error
4514** message all text up through the first zero character.
4515** ^If the third parameter to sqlite3_result_error() or
4516** sqlite3_result_error16() is non-negative then SQLite takes that many
4517** bytes (not characters) from the 2nd parameter as the error message.
4518** ^The sqlite3_result_error() and sqlite3_result_error16()
4519** routines make a private copy of the error message text before
4520** they return.  Hence, the calling function can deallocate or
4521** modify the text after they return without harm.
4522** ^The sqlite3_result_error_code() function changes the error code
4523** returned by SQLite as a result of an error in a function.  ^By default,
4524** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
4525** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4526**
4527** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
4528** indicating that a string or BLOB is too long to represent.
4529**
4530** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
4531** indicating that a memory allocation failed.
4532**
4533** ^The sqlite3_result_int() interface sets the return value
4534** of the application-defined function to be the 32-bit signed integer
4535** value given in the 2nd argument.
4536** ^The sqlite3_result_int64() interface sets the return value
4537** of the application-defined function to be the 64-bit signed integer
4538** value given in the 2nd argument.
4539**
4540** ^The sqlite3_result_null() interface sets the return value
4541** of the application-defined function to be NULL.
4542**
4543** ^The sqlite3_result_text(), sqlite3_result_text16(),
4544** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4545** set the return value of the application-defined function to be
4546** a text string which is represented as UTF-8, UTF-16 native byte order,
4547** UTF-16 little endian, or UTF-16 big endian, respectively.
4548** ^SQLite takes the text result from the application from
4549** the 2nd parameter of the sqlite3_result_text* interfaces.
4550** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4551** is negative, then SQLite takes result text from the 2nd parameter
4552** through the first zero character.
4553** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4554** is non-negative, then as many bytes (not characters) of the text
4555** pointed to by the 2nd parameter are taken as the application-defined
4556** function result.
4557** ^If the 4th parameter to the sqlite3_result_text* interfaces
4558** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4559** function as the destructor on the text or BLOB result when it has
4560** finished using that result.
4561** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4562** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4563** assumes that the text or BLOB result is in constant space and does not
4564** copy the content of the parameter nor call a destructor on the content
4565** when it has finished using that result.
4566** ^If the 4th parameter to the sqlite3_result_text* interfaces
4567** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4568** then SQLite makes a copy of the result into space obtained from
4569** from [sqlite3_malloc()] before it returns.
4570**
4571** ^The sqlite3_result_value() interface sets the result of
4572** the application-defined function to be a copy the
4573** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
4574** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4575** so that the [sqlite3_value] specified in the parameter may change or
4576** be deallocated after sqlite3_result_value() returns without harm.
4577** ^A [protected sqlite3_value] object may always be used where an
4578** [unprotected sqlite3_value] object is required, so either
4579** kind of [sqlite3_value] object can be used with this interface.
4580**
4581** If these routines are called from within the different thread
4582** than the one containing the application-defined function that received
4583** the [sqlite3_context] pointer, the results are undefined.
4584*/
4585SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4586SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4587SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4588SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4589SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4590SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4591SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4592SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4593SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4594SQLITE_API void sqlite3_result_null(sqlite3_context*);
4595SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4596SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4597SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4598SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4599SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4600SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4601
4602/*
4603** CAPI3REF: Define New Collating Sequences
4604**
4605** ^These functions add, remove, or modify a [collation] associated
4606** with the [database connection] specified as the first argument.
4607**
4608** ^The name of the collation is a UTF-8 string
4609** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4610** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4611** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4612** considered to be the same name.
4613**
4614** ^(The third argument (eTextRep) must be one of the constants:
4615** <ul>
4616** <li> [SQLITE_UTF8],
4617** <li> [SQLITE_UTF16LE],
4618** <li> [SQLITE_UTF16BE],
4619** <li> [SQLITE_UTF16], or
4620** <li> [SQLITE_UTF16_ALIGNED].
4621** </ul>)^
4622** ^The eTextRep argument determines the encoding of strings passed
4623** to the collating function callback, xCallback.
4624** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4625** force strings to be UTF16 with native byte order.
4626** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4627** on an even byte address.
4628**
4629** ^The fourth argument, pArg, is an application data pointer that is passed
4630** through as the first argument to the collating function callback.
4631**
4632** ^The fifth argument, xCallback, is a pointer to the collating function.
4633** ^Multiple collating functions can be registered using the same name but
4634** with different eTextRep parameters and SQLite will use whichever
4635** function requires the least amount of data transformation.
4636** ^If the xCallback argument is NULL then the collating function is
4637** deleted.  ^When all collating functions having the same name are deleted,
4638** that collation is no longer usable.
4639**
4640** ^The collating function callback is invoked with a copy of the pArg
4641** application data pointer and with two strings in the encoding specified
4642** by the eTextRep argument.  The collating function must return an
4643** integer that is negative, zero, or positive
4644** if the first string is less than, equal to, or greater than the second,
4645** respectively.  A collating function must always return the same answer
4646** given the same inputs.  If two or more collating functions are registered
4647** to the same collation name (using different eTextRep values) then all
4648** must give an equivalent answer when invoked with equivalent strings.
4649** The collating function must obey the following properties for all
4650** strings A, B, and C:
4651**
4652** <ol>
4653** <li> If A==B then B==A.
4654** <li> If A==B and B==C then A==C.
4655** <li> If A&lt;B THEN B&gt;A.
4656** <li> If A&lt;B and B&lt;C then A&lt;C.
4657** </ol>
4658**
4659** If a collating function fails any of the above constraints and that
4660** collating function is  registered and used, then the behavior of SQLite
4661** is undefined.
4662**
4663** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4664** with the addition that the xDestroy callback is invoked on pArg when
4665** the collating function is deleted.
4666** ^Collating functions are deleted when they are overridden by later
4667** calls to the collation creation functions or when the
4668** [database connection] is closed using [sqlite3_close()].
4669**
4670** ^The xDestroy callback is <u>not</u> called if the
4671** sqlite3_create_collation_v2() function fails.  Applications that invoke
4672** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4673** check the return code and dispose of the application data pointer
4674** themselves rather than expecting SQLite to deal with it for them.
4675** This is different from every other SQLite interface.  The inconsistency
4676** is unfortunate but cannot be changed without breaking backwards
4677** compatibility.
4678**
4679** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4680*/
4681SQLITE_API int sqlite3_create_collation(
4682  sqlite3*,
4683  const char *zName,
4684  int eTextRep,
4685  void *pArg,
4686  int(*xCompare)(void*,int,const void*,int,const void*)
4687);
4688SQLITE_API int sqlite3_create_collation_v2(
4689  sqlite3*,
4690  const char *zName,
4691  int eTextRep,
4692  void *pArg,
4693  int(*xCompare)(void*,int,const void*,int,const void*),
4694  void(*xDestroy)(void*)
4695);
4696SQLITE_API int sqlite3_create_collation16(
4697  sqlite3*,
4698  const void *zName,
4699  int eTextRep,
4700  void *pArg,
4701  int(*xCompare)(void*,int,const void*,int,const void*)
4702);
4703
4704/*
4705** CAPI3REF: Collation Needed Callbacks
4706**
4707** ^To avoid having to register all collation sequences before a database
4708** can be used, a single callback function may be registered with the
4709** [database connection] to be invoked whenever an undefined collation
4710** sequence is required.
4711**
4712** ^If the function is registered using the sqlite3_collation_needed() API,
4713** then it is passed the names of undefined collation sequences as strings
4714** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4715** the names are passed as UTF-16 in machine native byte order.
4716** ^A call to either function replaces the existing collation-needed callback.
4717**
4718** ^(When the callback is invoked, the first argument passed is a copy
4719** of the second argument to sqlite3_collation_needed() or
4720** sqlite3_collation_needed16().  The second argument is the database
4721** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4722** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4723** sequence function required.  The fourth parameter is the name of the
4724** required collation sequence.)^
4725**
4726** The callback function should register the desired collation using
4727** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4728** [sqlite3_create_collation_v2()].
4729*/
4730SQLITE_API int sqlite3_collation_needed(
4731  sqlite3*,
4732  void*,
4733  void(*)(void*,sqlite3*,int eTextRep,const char*)
4734);
4735SQLITE_API int sqlite3_collation_needed16(
4736  sqlite3*,
4737  void*,
4738  void(*)(void*,sqlite3*,int eTextRep,const void*)
4739);
4740
4741#ifdef SQLITE_HAS_CODEC
4742/*
4743** Specify the key for an encrypted database.  This routine should be
4744** called right after sqlite3_open().
4745**
4746** The code to implement this API is not available in the public release
4747** of SQLite.
4748*/
4749SQLITE_API int sqlite3_key(
4750  sqlite3 *db,                   /* Database to be rekeyed */
4751  const void *pKey, int nKey     /* The key */
4752);
4753
4754/*
4755** Change the key on an open database.  If the current database is not
4756** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
4757** database is decrypted.
4758**
4759** The code to implement this API is not available in the public release
4760** of SQLite.
4761*/
4762SQLITE_API int sqlite3_rekey(
4763  sqlite3 *db,                   /* Database to be rekeyed */
4764  const void *pKey, int nKey     /* The new key */
4765);
4766
4767/*
4768** Specify the activation key for a SEE database.  Unless
4769** activated, none of the SEE routines will work.
4770*/
4771SQLITE_API void sqlite3_activate_see(
4772  const char *zPassPhrase        /* Activation phrase */
4773);
4774#endif
4775
4776#ifdef SQLITE_ENABLE_CEROD
4777/*
4778** Specify the activation key for a CEROD database.  Unless
4779** activated, none of the CEROD routines will work.
4780*/
4781SQLITE_API void sqlite3_activate_cerod(
4782  const char *zPassPhrase        /* Activation phrase */
4783);
4784#endif
4785
4786/*
4787** CAPI3REF: Suspend Execution For A Short Time
4788**
4789** The sqlite3_sleep() function causes the current thread to suspend execution
4790** for at least a number of milliseconds specified in its parameter.
4791**
4792** If the operating system does not support sleep requests with
4793** millisecond time resolution, then the time will be rounded up to
4794** the nearest second. The number of milliseconds of sleep actually
4795** requested from the operating system is returned.
4796**
4797** ^SQLite implements this interface by calling the xSleep()
4798** method of the default [sqlite3_vfs] object.  If the xSleep() method
4799** of the default VFS is not implemented correctly, or not implemented at
4800** all, then the behavior of sqlite3_sleep() may deviate from the description
4801** in the previous paragraphs.
4802*/
4803SQLITE_API int sqlite3_sleep(int);
4804
4805/*
4806** CAPI3REF: Name Of The Folder Holding Temporary Files
4807**
4808** ^(If this global variable is made to point to a string which is
4809** the name of a folder (a.k.a. directory), then all temporary files
4810** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4811** will be placed in that directory.)^  ^If this variable
4812** is a NULL pointer, then SQLite performs a search for an appropriate
4813** temporary file directory.
4814**
4815** It is not safe to read or modify this variable in more than one
4816** thread at a time.  It is not safe to read or modify this variable
4817** if a [database connection] is being used at the same time in a separate
4818** thread.
4819** It is intended that this variable be set once
4820** as part of process initialization and before any SQLite interface
4821** routines have been called and that this variable remain unchanged
4822** thereafter.
4823**
4824** ^The [temp_store_directory pragma] may modify this variable and cause
4825** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4826** the [temp_store_directory pragma] always assumes that any string
4827** that this variable points to is held in memory obtained from
4828** [sqlite3_malloc] and the pragma may attempt to free that memory
4829** using [sqlite3_free].
4830** Hence, if this variable is modified directly, either it should be
4831** made NULL or made to point to memory obtained from [sqlite3_malloc]
4832** or else the use of the [temp_store_directory pragma] should be avoided.
4833*/
4834SQLITE_API char *sqlite3_temp_directory;
4835
4836/*
4837** CAPI3REF: Test For Auto-Commit Mode
4838** KEYWORDS: {autocommit mode}
4839**
4840** ^The sqlite3_get_autocommit() interface returns non-zero or
4841** zero if the given database connection is or is not in autocommit mode,
4842** respectively.  ^Autocommit mode is on by default.
4843** ^Autocommit mode is disabled by a [BEGIN] statement.
4844** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4845**
4846** If certain kinds of errors occur on a statement within a multi-statement
4847** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4848** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4849** transaction might be rolled back automatically.  The only way to
4850** find out whether SQLite automatically rolled back the transaction after
4851** an error is to use this function.
4852**
4853** If another thread changes the autocommit status of the database
4854** connection while this routine is running, then the return value
4855** is undefined.
4856*/
4857SQLITE_API int sqlite3_get_autocommit(sqlite3*);
4858
4859/*
4860** CAPI3REF: Find The Database Handle Of A Prepared Statement
4861**
4862** ^The sqlite3_db_handle interface returns the [database connection] handle
4863** to which a [prepared statement] belongs.  ^The [database connection]
4864** returned by sqlite3_db_handle is the same [database connection]
4865** that was the first argument
4866** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4867** create the statement in the first place.
4868*/
4869SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4870
4871/*
4872** CAPI3REF: Find the next prepared statement
4873**
4874** ^This interface returns a pointer to the next [prepared statement] after
4875** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
4876** then this interface returns a pointer to the first prepared statement
4877** associated with the database connection pDb.  ^If no prepared statement
4878** satisfies the conditions of this routine, it returns NULL.
4879**
4880** The [database connection] pointer D in a call to
4881** [sqlite3_next_stmt(D,S)] must refer to an open database
4882** connection and in particular must not be a NULL pointer.
4883*/
4884SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4885
4886/*
4887** CAPI3REF: Commit And Rollback Notification Callbacks
4888**
4889** ^The sqlite3_commit_hook() interface registers a callback
4890** function to be invoked whenever a transaction is [COMMIT | committed].
4891** ^Any callback set by a previous call to sqlite3_commit_hook()
4892** for the same database connection is overridden.
4893** ^The sqlite3_rollback_hook() interface registers a callback
4894** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4895** ^Any callback set by a previous call to sqlite3_rollback_hook()
4896** for the same database connection is overridden.
4897** ^The pArg argument is passed through to the callback.
4898** ^If the callback on a commit hook function returns non-zero,
4899** then the commit is converted into a rollback.
4900**
4901** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4902** return the P argument from the previous call of the same function
4903** on the same [database connection] D, or NULL for
4904** the first call for each function on D.
4905**
4906** The callback implementation must not do anything that will modify
4907** the database connection that invoked the callback.  Any actions
4908** to modify the database connection must be deferred until after the
4909** completion of the [sqlite3_step()] call that triggered the commit
4910** or rollback hook in the first place.
4911** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4912** database connections for the meaning of "modify" in this paragraph.
4913**
4914** ^Registering a NULL function disables the callback.
4915**
4916** ^When the commit hook callback routine returns zero, the [COMMIT]
4917** operation is allowed to continue normally.  ^If the commit hook
4918** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4919** ^The rollback hook is invoked on a rollback that results from a commit
4920** hook returning non-zero, just as it would be with any other rollback.
4921**
4922** ^For the purposes of this API, a transaction is said to have been
4923** rolled back if an explicit "ROLLBACK" statement is executed, or
4924** an error or constraint causes an implicit rollback to occur.
4925** ^The rollback callback is not invoked if a transaction is
4926** automatically rolled back because the database connection is closed.
4927**
4928** See also the [sqlite3_update_hook()] interface.
4929*/
4930SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4931SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4932
4933/*
4934** CAPI3REF: Data Change Notification Callbacks
4935**
4936** ^The sqlite3_update_hook() interface registers a callback function
4937** with the [database connection] identified by the first argument
4938** to be invoked whenever a row is updated, inserted or deleted.
4939** ^Any callback set by a previous call to this function
4940** for the same database connection is overridden.
4941**
4942** ^The second argument is a pointer to the function to invoke when a
4943** row is updated, inserted or deleted.
4944** ^The first argument to the callback is a copy of the third argument
4945** to sqlite3_update_hook().
4946** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4947** or [SQLITE_UPDATE], depending on the operation that caused the callback
4948** to be invoked.
4949** ^The third and fourth arguments to the callback contain pointers to the
4950** database and table name containing the affected row.
4951** ^The final callback parameter is the [rowid] of the row.
4952** ^In the case of an update, this is the [rowid] after the update takes place.
4953**
4954** ^(The update hook is not invoked when internal system tables are
4955** modified (i.e. sqlite_master and sqlite_sequence).)^
4956**
4957** ^In the current implementation, the update hook
4958** is not invoked when duplication rows are deleted because of an
4959** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
4960** invoked when rows are deleted using the [truncate optimization].
4961** The exceptions defined in this paragraph might change in a future
4962** release of SQLite.
4963**
4964** The update hook implementation must not do anything that will modify
4965** the database connection that invoked the update hook.  Any actions
4966** to modify the database connection must be deferred until after the
4967** completion of the [sqlite3_step()] call that triggered the update hook.
4968** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4969** database connections for the meaning of "modify" in this paragraph.
4970**
4971** ^The sqlite3_update_hook(D,C,P) function
4972** returns the P argument from the previous call
4973** on the same [database connection] D, or NULL for
4974** the first call on D.
4975**
4976** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4977** interfaces.
4978*/
4979SQLITE_API void *sqlite3_update_hook(
4980  sqlite3*,
4981  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4982  void*
4983);
4984
4985/*
4986** CAPI3REF: Enable Or Disable Shared Pager Cache
4987** KEYWORDS: {shared cache}
4988**
4989** ^(This routine enables or disables the sharing of the database cache
4990** and schema data structures between [database connection | connections]
4991** to the same database. Sharing is enabled if the argument is true
4992** and disabled if the argument is false.)^
4993**
4994** ^Cache sharing is enabled and disabled for an entire process.
4995** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4996** sharing was enabled or disabled for each thread separately.
4997**
4998** ^(The cache sharing mode set by this interface effects all subsequent
4999** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5000** Existing database connections continue use the sharing mode
5001** that was in effect at the time they were opened.)^
5002**
5003** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5004** successfully.  An [error code] is returned otherwise.)^
5005**
5006** ^Shared cache is disabled by default. But this might change in
5007** future releases of SQLite.  Applications that care about shared
5008** cache setting should set it explicitly.
5009**
5010** See Also:  [SQLite Shared-Cache Mode]
5011*/
5012SQLITE_API int sqlite3_enable_shared_cache(int);
5013
5014/*
5015** CAPI3REF: Attempt To Free Heap Memory
5016**
5017** ^The sqlite3_release_memory() interface attempts to free N bytes
5018** of heap memory by deallocating non-essential memory allocations
5019** held by the database library.   Memory used to cache database
5020** pages to improve performance is an example of non-essential memory.
5021** ^sqlite3_release_memory() returns the number of bytes actually freed,
5022** which might be more or less than the amount requested.
5023** ^The sqlite3_release_memory() routine is a no-op returning zero
5024** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5025*/
5026SQLITE_API int sqlite3_release_memory(int);
5027
5028/*
5029** CAPI3REF: Impose A Limit On Heap Size
5030**
5031** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5032** soft limit on the amount of heap memory that may be allocated by SQLite.
5033** ^SQLite strives to keep heap memory utilization below the soft heap
5034** limit by reducing the number of pages held in the page cache
5035** as heap memory usages approaches the limit.
5036** ^The soft heap limit is "soft" because even though SQLite strives to stay
5037** below the limit, it will exceed the limit rather than generate
5038** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
5039** is advisory only.
5040**
5041** ^The return value from sqlite3_soft_heap_limit64() is the size of
5042** the soft heap limit prior to the call.  ^If the argument N is negative
5043** then no change is made to the soft heap limit.  Hence, the current
5044** size of the soft heap limit can be determined by invoking
5045** sqlite3_soft_heap_limit64() with a negative argument.
5046**
5047** ^If the argument N is zero then the soft heap limit is disabled.
5048**
5049** ^(The soft heap limit is not enforced in the current implementation
5050** if one or more of following conditions are true:
5051**
5052** <ul>
5053** <li> The soft heap limit is set to zero.
5054** <li> Memory accounting is disabled using a combination of the
5055**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5056**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5057** <li> An alternative page cache implementation is specified using
5058**      [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
5059** <li> The page cache allocates from its own memory pool supplied
5060**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5061**      from the heap.
5062** </ul>)^
5063**
5064** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5065** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5066** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5067** the soft heap limit is enforced on every memory allocation.  Without
5068** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5069** when memory is allocated by the page cache.  Testing suggests that because
5070** the page cache is the predominate memory user in SQLite, most
5071** applications will achieve adequate soft heap limit enforcement without
5072** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5073**
5074** The circumstances under which SQLite will enforce the soft heap limit may
5075** changes in future releases of SQLite.
5076*/
5077SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5078
5079/*
5080** CAPI3REF: Deprecated Soft Heap Limit Interface
5081** DEPRECATED
5082**
5083** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5084** interface.  This routine is provided for historical compatibility
5085** only.  All new applications should use the
5086** [sqlite3_soft_heap_limit64()] interface rather than this one.
5087*/
5088SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5089
5090
5091/*
5092** CAPI3REF: Extract Metadata About A Column Of A Table
5093**
5094** ^This routine returns metadata about a specific column of a specific
5095** database table accessible using the [database connection] handle
5096** passed as the first function argument.
5097**
5098** ^The column is identified by the second, third and fourth parameters to
5099** this function. ^The second parameter is either the name of the database
5100** (i.e. "main", "temp", or an attached database) containing the specified
5101** table or NULL. ^If it is NULL, then all attached databases are searched
5102** for the table using the same algorithm used by the database engine to
5103** resolve unqualified table references.
5104**
5105** ^The third and fourth parameters to this function are the table and column
5106** name of the desired column, respectively. Neither of these parameters
5107** may be NULL.
5108**
5109** ^Metadata is returned by writing to the memory locations passed as the 5th
5110** and subsequent parameters to this function. ^Any of these arguments may be
5111** NULL, in which case the corresponding element of metadata is omitted.
5112**
5113** ^(<blockquote>
5114** <table border="1">
5115** <tr><th> Parameter <th> Output<br>Type <th>  Description
5116**
5117** <tr><td> 5th <td> const char* <td> Data type
5118** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5119** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
5120** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
5121** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
5122** </table>
5123** </blockquote>)^
5124**
5125** ^The memory pointed to by the character pointers returned for the
5126** declaration type and collation sequence is valid only until the next
5127** call to any SQLite API function.
5128**
5129** ^If the specified table is actually a view, an [error code] is returned.
5130**
5131** ^If the specified column is "rowid", "oid" or "_rowid_" and an
5132** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5133** parameters are set for the explicitly declared column. ^(If there is no
5134** explicitly declared [INTEGER PRIMARY KEY] column, then the output
5135** parameters are set as follows:
5136**
5137** <pre>
5138**     data type: "INTEGER"
5139**     collation sequence: "BINARY"
5140**     not null: 0
5141**     primary key: 1
5142**     auto increment: 0
5143** </pre>)^
5144**
5145** ^(This function may load one or more schemas from database files. If an
5146** error occurs during this process, or if the requested table or column
5147** cannot be found, an [error code] is returned and an error message left
5148** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
5149**
5150** ^This API is only available if the library was compiled with the
5151** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5152*/
5153SQLITE_API int sqlite3_table_column_metadata(
5154  sqlite3 *db,                /* Connection handle */
5155  const char *zDbName,        /* Database name or NULL */
5156  const char *zTableName,     /* Table name */
5157  const char *zColumnName,    /* Column name */
5158  char const **pzDataType,    /* OUTPUT: Declared data type */
5159  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
5160  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
5161  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
5162  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
5163);
5164
5165/*
5166** CAPI3REF: Load An Extension
5167**
5168** ^This interface loads an SQLite extension library from the named file.
5169**
5170** ^The sqlite3_load_extension() interface attempts to load an
5171** SQLite extension library contained in the file zFile.
5172**
5173** ^The entry point is zProc.
5174** ^zProc may be 0, in which case the name of the entry point
5175** defaults to "sqlite3_extension_init".
5176** ^The sqlite3_load_extension() interface returns
5177** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5178** ^If an error occurs and pzErrMsg is not 0, then the
5179** [sqlite3_load_extension()] interface shall attempt to
5180** fill *pzErrMsg with error message text stored in memory
5181** obtained from [sqlite3_malloc()]. The calling function
5182** should free this memory by calling [sqlite3_free()].
5183**
5184** ^Extension loading must be enabled using
5185** [sqlite3_enable_load_extension()] prior to calling this API,
5186** otherwise an error will be returned.
5187**
5188** See also the [load_extension() SQL function].
5189*/
5190SQLITE_API int sqlite3_load_extension(
5191  sqlite3 *db,          /* Load the extension into this database connection */
5192  const char *zFile,    /* Name of the shared library containing extension */
5193  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
5194  char **pzErrMsg       /* Put error message here if not 0 */
5195);
5196
5197/*
5198** CAPI3REF: Enable Or Disable Extension Loading
5199**
5200** ^So as not to open security holes in older applications that are
5201** unprepared to deal with extension loading, and as a means of disabling
5202** extension loading while evaluating user-entered SQL, the following API
5203** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5204**
5205** ^Extension loading is off by default. See ticket #1863.
5206** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5207** to turn extension loading on and call it with onoff==0 to turn
5208** it back off again.
5209*/
5210SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5211
5212/*
5213** CAPI3REF: Automatically Load Statically Linked Extensions
5214**
5215** ^This interface causes the xEntryPoint() function to be invoked for
5216** each new [database connection] that is created.  The idea here is that
5217** xEntryPoint() is the entry point for a statically linked SQLite extension
5218** that is to be automatically loaded into all new database connections.
5219**
5220** ^(Even though the function prototype shows that xEntryPoint() takes
5221** no arguments and returns void, SQLite invokes xEntryPoint() with three
5222** arguments and expects and integer result as if the signature of the
5223** entry point where as follows:
5224**
5225** <blockquote><pre>
5226** &nbsp;  int xEntryPoint(
5227** &nbsp;    sqlite3 *db,
5228** &nbsp;    const char **pzErrMsg,
5229** &nbsp;    const struct sqlite3_api_routines *pThunk
5230** &nbsp;  );
5231** </pre></blockquote>)^
5232**
5233** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5234** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5235** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
5236** is NULL before calling the xEntryPoint().  ^SQLite will invoke
5237** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
5238** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5239** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5240**
5241** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5242** on the list of automatic extensions is a harmless no-op. ^No entry point
5243** will be called more than once for each database connection that is opened.
5244**
5245** See also: [sqlite3_reset_auto_extension()].
5246*/
5247SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5248
5249/*
5250** CAPI3REF: Reset Automatic Extension Loading
5251**
5252** ^This interface disables all automatic extensions previously
5253** registered using [sqlite3_auto_extension()].
5254*/
5255SQLITE_API void sqlite3_reset_auto_extension(void);
5256
5257/*
5258** The interface to the virtual-table mechanism is currently considered
5259** to be experimental.  The interface might change in incompatible ways.
5260** If this is a problem for you, do not use the interface at this time.
5261**
5262** When the virtual-table mechanism stabilizes, we will declare the
5263** interface fixed, support it indefinitely, and remove this comment.
5264*/
5265
5266/*
5267** Structures used by the virtual table interface
5268*/
5269typedef struct sqlite3_vtab sqlite3_vtab;
5270typedef struct sqlite3_index_info sqlite3_index_info;
5271typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5272typedef struct sqlite3_module sqlite3_module;
5273
5274/*
5275** CAPI3REF: Virtual Table Object
5276** KEYWORDS: sqlite3_module {virtual table module}
5277**
5278** This structure, sometimes called a "virtual table module",
5279** defines the implementation of a [virtual tables].
5280** This structure consists mostly of methods for the module.
5281**
5282** ^A virtual table module is created by filling in a persistent
5283** instance of this structure and passing a pointer to that instance
5284** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5285** ^The registration remains valid until it is replaced by a different
5286** module or until the [database connection] closes.  The content
5287** of this structure must not change while it is registered with
5288** any database connection.
5289*/
5290struct sqlite3_module {
5291  int iVersion;
5292  int (*xCreate)(sqlite3*, void *pAux,
5293               int argc, const char *const*argv,
5294               sqlite3_vtab **ppVTab, char**);
5295  int (*xConnect)(sqlite3*, void *pAux,
5296               int argc, const char *const*argv,
5297               sqlite3_vtab **ppVTab, char**);
5298  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5299  int (*xDisconnect)(sqlite3_vtab *pVTab);
5300  int (*xDestroy)(sqlite3_vtab *pVTab);
5301  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5302  int (*xClose)(sqlite3_vtab_cursor*);
5303  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5304                int argc, sqlite3_value **argv);
5305  int (*xNext)(sqlite3_vtab_cursor*);
5306  int (*xEof)(sqlite3_vtab_cursor*);
5307  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5308  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5309  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5310  int (*xBegin)(sqlite3_vtab *pVTab);
5311  int (*xSync)(sqlite3_vtab *pVTab);
5312  int (*xCommit)(sqlite3_vtab *pVTab);
5313  int (*xRollback)(sqlite3_vtab *pVTab);
5314  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5315                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5316                       void **ppArg);
5317  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5318  /* The methods above are in version 1 of the sqlite_module object. Those
5319  ** below are for version 2 and greater. */
5320  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5321  int (*xRelease)(sqlite3_vtab *pVTab, int);
5322  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5323};
5324
5325/*
5326** CAPI3REF: Virtual Table Indexing Information
5327** KEYWORDS: sqlite3_index_info
5328**
5329** The sqlite3_index_info structure and its substructures is used as part
5330** of the [virtual table] interface to
5331** pass information into and receive the reply from the [xBestIndex]
5332** method of a [virtual table module].  The fields under **Inputs** are the
5333** inputs to xBestIndex and are read-only.  xBestIndex inserts its
5334** results into the **Outputs** fields.
5335**
5336** ^(The aConstraint[] array records WHERE clause constraints of the form:
5337**
5338** <blockquote>column OP expr</blockquote>
5339**
5340** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
5341** stored in aConstraint[].op using one of the
5342** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5343** ^(The index of the column is stored in
5344** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
5345** expr on the right-hand side can be evaluated (and thus the constraint
5346** is usable) and false if it cannot.)^
5347**
5348** ^The optimizer automatically inverts terms of the form "expr OP column"
5349** and makes other simplifications to the WHERE clause in an attempt to
5350** get as many WHERE clause terms into the form shown above as possible.
5351** ^The aConstraint[] array only reports WHERE clause terms that are
5352** relevant to the particular virtual table being queried.
5353**
5354** ^Information about the ORDER BY clause is stored in aOrderBy[].
5355** ^Each term of aOrderBy records a column of the ORDER BY clause.
5356**
5357** The [xBestIndex] method must fill aConstraintUsage[] with information
5358** about what parameters to pass to xFilter.  ^If argvIndex>0 then
5359** the right-hand side of the corresponding aConstraint[] is evaluated
5360** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
5361** is true, then the constraint is assumed to be fully handled by the
5362** virtual table and is not checked again by SQLite.)^
5363**
5364** ^The idxNum and idxPtr values are recorded and passed into the
5365** [xFilter] method.
5366** ^[sqlite3_free()] is used to free idxPtr if and only if
5367** needToFreeIdxPtr is true.
5368**
5369** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5370** the correct order to satisfy the ORDER BY clause so that no separate
5371** sorting step is required.
5372**
5373** ^The estimatedCost value is an estimate of the cost of doing the
5374** particular lookup.  A full scan of a table with N entries should have
5375** a cost of N.  A binary search of a table of N entries should have a
5376** cost of approximately log(N).
5377*/
5378struct sqlite3_index_info {
5379  /* Inputs */
5380  int nConstraint;           /* Number of entries in aConstraint */
5381  struct sqlite3_index_constraint {
5382     int iColumn;              /* Column on left-hand side of constraint */
5383     unsigned char op;         /* Constraint operator */
5384     unsigned char usable;     /* True if this constraint is usable */
5385     int iTermOffset;          /* Used internally - xBestIndex should ignore */
5386  } *aConstraint;            /* Table of WHERE clause constraints */
5387  int nOrderBy;              /* Number of terms in the ORDER BY clause */
5388  struct sqlite3_index_orderby {
5389     int iColumn;              /* Column number */
5390     unsigned char desc;       /* True for DESC.  False for ASC. */
5391  } *aOrderBy;               /* The ORDER BY clause */
5392  /* Outputs */
5393  struct sqlite3_index_constraint_usage {
5394    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
5395    unsigned char omit;      /* Do not code a test for this constraint */
5396  } *aConstraintUsage;
5397  int idxNum;                /* Number used to identify the index */
5398  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
5399  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
5400  int orderByConsumed;       /* True if output is already ordered */
5401  double estimatedCost;      /* Estimated cost of using this index */
5402};
5403
5404/*
5405** CAPI3REF: Virtual Table Constraint Operator Codes
5406**
5407** These macros defined the allowed values for the
5408** [sqlite3_index_info].aConstraint[].op field.  Each value represents
5409** an operator that is part of a constraint term in the wHERE clause of
5410** a query that uses a [virtual table].
5411*/
5412#define SQLITE_INDEX_CONSTRAINT_EQ    2
5413#define SQLITE_INDEX_CONSTRAINT_GT    4
5414#define SQLITE_INDEX_CONSTRAINT_LE    8
5415#define SQLITE_INDEX_CONSTRAINT_LT    16
5416#define SQLITE_INDEX_CONSTRAINT_GE    32
5417#define SQLITE_INDEX_CONSTRAINT_MATCH 64
5418
5419/*
5420** CAPI3REF: Register A Virtual Table Implementation
5421**
5422** ^These routines are used to register a new [virtual table module] name.
5423** ^Module names must be registered before
5424** creating a new [virtual table] using the module and before using a
5425** preexisting [virtual table] for the module.
5426**
5427** ^The module name is registered on the [database connection] specified
5428** by the first parameter.  ^The name of the module is given by the
5429** second parameter.  ^The third parameter is a pointer to
5430** the implementation of the [virtual table module].   ^The fourth
5431** parameter is an arbitrary client data pointer that is passed through
5432** into the [xCreate] and [xConnect] methods of the virtual table module
5433** when a new virtual table is be being created or reinitialized.
5434**
5435** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5436** is a pointer to a destructor for the pClientData.  ^SQLite will
5437** invoke the destructor function (if it is not NULL) when SQLite
5438** no longer needs the pClientData pointer.  ^The destructor will also
5439** be invoked if the call to sqlite3_create_module_v2() fails.
5440** ^The sqlite3_create_module()
5441** interface is equivalent to sqlite3_create_module_v2() with a NULL
5442** destructor.
5443*/
5444SQLITE_API int sqlite3_create_module(
5445  sqlite3 *db,               /* SQLite connection to register module with */
5446  const char *zName,         /* Name of the module */
5447  const sqlite3_module *p,   /* Methods for the module */
5448  void *pClientData          /* Client data for xCreate/xConnect */
5449);
5450SQLITE_API int sqlite3_create_module_v2(
5451  sqlite3 *db,               /* SQLite connection to register module with */
5452  const char *zName,         /* Name of the module */
5453  const sqlite3_module *p,   /* Methods for the module */
5454  void *pClientData,         /* Client data for xCreate/xConnect */
5455  void(*xDestroy)(void*)     /* Module destructor function */
5456);
5457
5458/*
5459** CAPI3REF: Virtual Table Instance Object
5460** KEYWORDS: sqlite3_vtab
5461**
5462** Every [virtual table module] implementation uses a subclass
5463** of this object to describe a particular instance
5464** of the [virtual table].  Each subclass will
5465** be tailored to the specific needs of the module implementation.
5466** The purpose of this superclass is to define certain fields that are
5467** common to all module implementations.
5468**
5469** ^Virtual tables methods can set an error message by assigning a
5470** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
5471** take care that any prior string is freed by a call to [sqlite3_free()]
5472** prior to assigning a new string to zErrMsg.  ^After the error message
5473** is delivered up to the client application, the string will be automatically
5474** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5475*/
5476struct sqlite3_vtab {
5477  const sqlite3_module *pModule;  /* The module for this virtual table */
5478  int nRef;                       /* NO LONGER USED */
5479  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
5480  /* Virtual table implementations will typically add additional fields */
5481};
5482
5483/*
5484** CAPI3REF: Virtual Table Cursor Object
5485** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5486**
5487** Every [virtual table module] implementation uses a subclass of the
5488** following structure to describe cursors that point into the
5489** [virtual table] and are used
5490** to loop through the virtual table.  Cursors are created using the
5491** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5492** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
5493** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5494** of the module.  Each module implementation will define
5495** the content of a cursor structure to suit its own needs.
5496**
5497** This superclass exists in order to define fields of the cursor that
5498** are common to all implementations.
5499*/
5500struct sqlite3_vtab_cursor {
5501  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
5502  /* Virtual table implementations will typically add additional fields */
5503};
5504
5505/*
5506** CAPI3REF: Declare The Schema Of A Virtual Table
5507**
5508** ^The [xCreate] and [xConnect] methods of a
5509** [virtual table module] call this interface
5510** to declare the format (the names and datatypes of the columns) of
5511** the virtual tables they implement.
5512*/
5513SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5514
5515/*
5516** CAPI3REF: Overload A Function For A Virtual Table
5517**
5518** ^(Virtual tables can provide alternative implementations of functions
5519** using the [xFindFunction] method of the [virtual table module].
5520** But global versions of those functions
5521** must exist in order to be overloaded.)^
5522**
5523** ^(This API makes sure a global version of a function with a particular
5524** name and number of parameters exists.  If no such function exists
5525** before this API is called, a new function is created.)^  ^The implementation
5526** of the new function always causes an exception to be thrown.  So
5527** the new function is not good for anything by itself.  Its only
5528** purpose is to be a placeholder function that can be overloaded
5529** by a [virtual table].
5530*/
5531SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5532
5533/*
5534** The interface to the virtual-table mechanism defined above (back up
5535** to a comment remarkably similar to this one) is currently considered
5536** to be experimental.  The interface might change in incompatible ways.
5537** If this is a problem for you, do not use the interface at this time.
5538**
5539** When the virtual-table mechanism stabilizes, we will declare the
5540** interface fixed, support it indefinitely, and remove this comment.
5541*/
5542
5543/*
5544** CAPI3REF: A Handle To An Open BLOB
5545** KEYWORDS: {BLOB handle} {BLOB handles}
5546**
5547** An instance of this object represents an open BLOB on which
5548** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5549** ^Objects of this type are created by [sqlite3_blob_open()]
5550** and destroyed by [sqlite3_blob_close()].
5551** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5552** can be used to read or write small subsections of the BLOB.
5553** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5554*/
5555typedef struct sqlite3_blob sqlite3_blob;
5556
5557/*
5558** CAPI3REF: Open A BLOB For Incremental I/O
5559**
5560** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5561** in row iRow, column zColumn, table zTable in database zDb;
5562** in other words, the same BLOB that would be selected by:
5563**
5564** <pre>
5565**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5566** </pre>)^
5567**
5568** ^If the flags parameter is non-zero, then the BLOB is opened for read
5569** and write access. ^If it is zero, the BLOB is opened for read access.
5570** ^It is not possible to open a column that is part of an index or primary
5571** key for writing. ^If [foreign key constraints] are enabled, it is
5572** not possible to open a column that is part of a [child key] for writing.
5573**
5574** ^Note that the database name is not the filename that contains
5575** the database but rather the symbolic name of the database that
5576** appears after the AS keyword when the database is connected using [ATTACH].
5577** ^For the main database file, the database name is "main".
5578** ^For TEMP tables, the database name is "temp".
5579**
5580** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5581** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5582** to be a null pointer.)^
5583** ^This function sets the [database connection] error code and message
5584** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5585** functions. ^Note that the *ppBlob variable is always initialized in a
5586** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5587** regardless of the success or failure of this routine.
5588**
5589** ^(If the row that a BLOB handle points to is modified by an
5590** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5591** then the BLOB handle is marked as "expired".
5592** This is true if any column of the row is changed, even a column
5593** other than the one the BLOB handle is open on.)^
5594** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5595** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5596** ^(Changes written into a BLOB prior to the BLOB expiring are not
5597** rolled back by the expiration of the BLOB.  Such changes will eventually
5598** commit if the transaction continues to completion.)^
5599**
5600** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5601** the opened blob.  ^The size of a blob may not be changed by this
5602** interface.  Use the [UPDATE] SQL command to change the size of a
5603** blob.
5604**
5605** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5606** and the built-in [zeroblob] SQL function can be used, if desired,
5607** to create an empty, zero-filled blob in which to read or write using
5608** this interface.
5609**
5610** To avoid a resource leak, every open [BLOB handle] should eventually
5611** be released by a call to [sqlite3_blob_close()].
5612*/
5613SQLITE_API int sqlite3_blob_open(
5614  sqlite3*,
5615  const char *zDb,
5616  const char *zTable,
5617  const char *zColumn,
5618  sqlite3_int64 iRow,
5619  int flags,
5620  sqlite3_blob **ppBlob
5621);
5622
5623/*
5624** CAPI3REF: Move a BLOB Handle to a New Row
5625**
5626** ^This function is used to move an existing blob handle so that it points
5627** to a different row of the same database table. ^The new row is identified
5628** by the rowid value passed as the second argument. Only the row can be
5629** changed. ^The database, table and column on which the blob handle is open
5630** remain the same. Moving an existing blob handle to a new row can be
5631** faster than closing the existing handle and opening a new one.
5632**
5633** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5634** it must exist and there must be either a blob or text value stored in
5635** the nominated column.)^ ^If the new row is not present in the table, or if
5636** it does not contain a blob or text value, or if another error occurs, an
5637** SQLite error code is returned and the blob handle is considered aborted.
5638** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5639** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5640** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5641** always returns zero.
5642**
5643** ^This function sets the database handle error code and message.
5644*/
5645SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
5646
5647/*
5648** CAPI3REF: Close A BLOB Handle
5649**
5650** ^Closes an open [BLOB handle].
5651**
5652** ^Closing a BLOB shall cause the current transaction to commit
5653** if there are no other BLOBs, no pending prepared statements, and the
5654** database connection is in [autocommit mode].
5655** ^If any writes were made to the BLOB, they might be held in cache
5656** until the close operation if they will fit.
5657**
5658** ^(Closing the BLOB often forces the changes
5659** out to disk and so if any I/O errors occur, they will likely occur
5660** at the time when the BLOB is closed.  Any errors that occur during
5661** closing are reported as a non-zero return value.)^
5662**
5663** ^(The BLOB is closed unconditionally.  Even if this routine returns
5664** an error code, the BLOB is still closed.)^
5665**
5666** ^Calling this routine with a null pointer (such as would be returned
5667** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5668*/
5669SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5670
5671/*
5672** CAPI3REF: Return The Size Of An Open BLOB
5673**
5674** ^Returns the size in bytes of the BLOB accessible via the
5675** successfully opened [BLOB handle] in its only argument.  ^The
5676** incremental blob I/O routines can only read or overwriting existing
5677** blob content; they cannot change the size of a blob.
5678**
5679** This routine only works on a [BLOB handle] which has been created
5680** by a prior successful call to [sqlite3_blob_open()] and which has not
5681** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5682** to this routine results in undefined and probably undesirable behavior.
5683*/
5684SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5685
5686/*
5687** CAPI3REF: Read Data From A BLOB Incrementally
5688**
5689** ^(This function is used to read data from an open [BLOB handle] into a
5690** caller-supplied buffer. N bytes of data are copied into buffer Z
5691** from the open BLOB, starting at offset iOffset.)^
5692**
5693** ^If offset iOffset is less than N bytes from the end of the BLOB,
5694** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
5695** less than zero, [SQLITE_ERROR] is returned and no data is read.
5696** ^The size of the blob (and hence the maximum value of N+iOffset)
5697** can be determined using the [sqlite3_blob_bytes()] interface.
5698**
5699** ^An attempt to read from an expired [BLOB handle] fails with an
5700** error code of [SQLITE_ABORT].
5701**
5702** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5703** Otherwise, an [error code] or an [extended error code] is returned.)^
5704**
5705** This routine only works on a [BLOB handle] which has been created
5706** by a prior successful call to [sqlite3_blob_open()] and which has not
5707** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5708** to this routine results in undefined and probably undesirable behavior.
5709**
5710** See also: [sqlite3_blob_write()].
5711*/
5712SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5713
5714/*
5715** CAPI3REF: Write Data Into A BLOB Incrementally
5716**
5717** ^This function is used to write data into an open [BLOB handle] from a
5718** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5719** into the open BLOB, starting at offset iOffset.
5720**
5721** ^If the [BLOB handle] passed as the first argument was not opened for
5722** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5723** this function returns [SQLITE_READONLY].
5724**
5725** ^This function may only modify the contents of the BLOB; it is
5726** not possible to increase the size of a BLOB using this API.
5727** ^If offset iOffset is less than N bytes from the end of the BLOB,
5728** [SQLITE_ERROR] is returned and no data is written.  ^If N is
5729** less than zero [SQLITE_ERROR] is returned and no data is written.
5730** The size of the BLOB (and hence the maximum value of N+iOffset)
5731** can be determined using the [sqlite3_blob_bytes()] interface.
5732**
5733** ^An attempt to write to an expired [BLOB handle] fails with an
5734** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
5735** before the [BLOB handle] expired are not rolled back by the
5736** expiration of the handle, though of course those changes might
5737** have been overwritten by the statement that expired the BLOB handle
5738** or by other independent statements.
5739**
5740** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5741** Otherwise, an  [error code] or an [extended error code] is returned.)^
5742**
5743** This routine only works on a [BLOB handle] which has been created
5744** by a prior successful call to [sqlite3_blob_open()] and which has not
5745** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5746** to this routine results in undefined and probably undesirable behavior.
5747**
5748** See also: [sqlite3_blob_read()].
5749*/
5750SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5751
5752/*
5753** CAPI3REF: Virtual File System Objects
5754**
5755** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5756** that SQLite uses to interact
5757** with the underlying operating system.  Most SQLite builds come with a
5758** single default VFS that is appropriate for the host computer.
5759** New VFSes can be registered and existing VFSes can be unregistered.
5760** The following interfaces are provided.
5761**
5762** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5763** ^Names are case sensitive.
5764** ^Names are zero-terminated UTF-8 strings.
5765** ^If there is no match, a NULL pointer is returned.
5766** ^If zVfsName is NULL then the default VFS is returned.
5767**
5768** ^New VFSes are registered with sqlite3_vfs_register().
5769** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5770** ^The same VFS can be registered multiple times without injury.
5771** ^To make an existing VFS into the default VFS, register it again
5772** with the makeDflt flag set.  If two different VFSes with the
5773** same name are registered, the behavior is undefined.  If a
5774** VFS is registered with a name that is NULL or an empty string,
5775** then the behavior is undefined.
5776**
5777** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5778** ^(If the default VFS is unregistered, another VFS is chosen as
5779** the default.  The choice for the new VFS is arbitrary.)^
5780*/
5781SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5782SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5783SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5784
5785/*
5786** CAPI3REF: Mutexes
5787**
5788** The SQLite core uses these routines for thread
5789** synchronization. Though they are intended for internal
5790** use by SQLite, code that links against SQLite is
5791** permitted to use any of these routines.
5792**
5793** The SQLite source code contains multiple implementations
5794** of these mutex routines.  An appropriate implementation
5795** is selected automatically at compile-time.  ^(The following
5796** implementations are available in the SQLite core:
5797**
5798** <ul>
5799** <li>   SQLITE_MUTEX_OS2
5800** <li>   SQLITE_MUTEX_PTHREAD
5801** <li>   SQLITE_MUTEX_W32
5802** <li>   SQLITE_MUTEX_NOOP
5803** </ul>)^
5804**
5805** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5806** that does no real locking and is appropriate for use in
5807** a single-threaded application.  ^The SQLITE_MUTEX_OS2,
5808** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
5809** are appropriate for use on OS/2, Unix, and Windows.
5810**
5811** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5812** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5813** implementation is included with the library. In this case the
5814** application must supply a custom mutex implementation using the
5815** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5816** before calling sqlite3_initialize() or any other public sqlite3_
5817** function that calls sqlite3_initialize().)^
5818**
5819** ^The sqlite3_mutex_alloc() routine allocates a new
5820** mutex and returns a pointer to it. ^If it returns NULL
5821** that means that a mutex could not be allocated.  ^SQLite
5822** will unwind its stack and return an error.  ^(The argument
5823** to sqlite3_mutex_alloc() is one of these integer constants:
5824**
5825** <ul>
5826** <li>  SQLITE_MUTEX_FAST
5827** <li>  SQLITE_MUTEX_RECURSIVE
5828** <li>  SQLITE_MUTEX_STATIC_MASTER
5829** <li>  SQLITE_MUTEX_STATIC_MEM
5830** <li>  SQLITE_MUTEX_STATIC_MEM2
5831** <li>  SQLITE_MUTEX_STATIC_PRNG
5832** <li>  SQLITE_MUTEX_STATIC_LRU
5833** <li>  SQLITE_MUTEX_STATIC_LRU2
5834** </ul>)^
5835**
5836** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5837** cause sqlite3_mutex_alloc() to create
5838** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5839** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5840** The mutex implementation does not need to make a distinction
5841** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5842** not want to.  ^SQLite will only request a recursive mutex in
5843** cases where it really needs one.  ^If a faster non-recursive mutex
5844** implementation is available on the host platform, the mutex subsystem
5845** might return such a mutex in response to SQLITE_MUTEX_FAST.
5846**
5847** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5848** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5849** a pointer to a static preexisting mutex.  ^Six static mutexes are
5850** used by the current version of SQLite.  Future versions of SQLite
5851** may add additional static mutexes.  Static mutexes are for internal
5852** use by SQLite only.  Applications that use SQLite mutexes should
5853** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5854** SQLITE_MUTEX_RECURSIVE.
5855**
5856** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5857** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5858** returns a different mutex on every call.  ^But for the static
5859** mutex types, the same mutex is returned on every call that has
5860** the same type number.
5861**
5862** ^The sqlite3_mutex_free() routine deallocates a previously
5863** allocated dynamic mutex.  ^SQLite is careful to deallocate every
5864** dynamic mutex that it allocates.  The dynamic mutexes must not be in
5865** use when they are deallocated.  Attempting to deallocate a static
5866** mutex results in undefined behavior.  ^SQLite never deallocates
5867** a static mutex.
5868**
5869** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5870** to enter a mutex.  ^If another thread is already within the mutex,
5871** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5872** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5873** upon successful entry.  ^(Mutexes created using
5874** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5875** In such cases the,
5876** mutex must be exited an equal number of times before another thread
5877** can enter.)^  ^(If the same thread tries to enter any other
5878** kind of mutex more than once, the behavior is undefined.
5879** SQLite will never exhibit
5880** such behavior in its own use of mutexes.)^
5881**
5882** ^(Some systems (for example, Windows 95) do not support the operation
5883** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
5884** will always return SQLITE_BUSY.  The SQLite core only ever uses
5885** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5886**
5887** ^The sqlite3_mutex_leave() routine exits a mutex that was
5888** previously entered by the same thread.   ^(The behavior
5889** is undefined if the mutex is not currently entered by the
5890** calling thread or is not currently allocated.  SQLite will
5891** never do either.)^
5892**
5893** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5894** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5895** behave as no-ops.
5896**
5897** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5898*/
5899SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
5900SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
5901SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
5902SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
5903SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
5904
5905/*
5906** CAPI3REF: Mutex Methods Object
5907**
5908** An instance of this structure defines the low-level routines
5909** used to allocate and use mutexes.
5910**
5911** Usually, the default mutex implementations provided by SQLite are
5912** sufficient, however the user has the option of substituting a custom
5913** implementation for specialized deployments or systems for which SQLite
5914** does not provide a suitable implementation. In this case, the user
5915** creates and populates an instance of this structure to pass
5916** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5917** Additionally, an instance of this structure can be used as an
5918** output variable when querying the system for the current mutex
5919** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5920**
5921** ^The xMutexInit method defined by this structure is invoked as
5922** part of system initialization by the sqlite3_initialize() function.
5923** ^The xMutexInit routine is called by SQLite exactly once for each
5924** effective call to [sqlite3_initialize()].
5925**
5926** ^The xMutexEnd method defined by this structure is invoked as
5927** part of system shutdown by the sqlite3_shutdown() function. The
5928** implementation of this method is expected to release all outstanding
5929** resources obtained by the mutex methods implementation, especially
5930** those obtained by the xMutexInit method.  ^The xMutexEnd()
5931** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5932**
5933** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5934** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5935** xMutexNotheld) implement the following interfaces (respectively):
5936**
5937** <ul>
5938**   <li>  [sqlite3_mutex_alloc()] </li>
5939**   <li>  [sqlite3_mutex_free()] </li>
5940**   <li>  [sqlite3_mutex_enter()] </li>
5941**   <li>  [sqlite3_mutex_try()] </li>
5942**   <li>  [sqlite3_mutex_leave()] </li>
5943**   <li>  [sqlite3_mutex_held()] </li>
5944**   <li>  [sqlite3_mutex_notheld()] </li>
5945** </ul>)^
5946**
5947** The only difference is that the public sqlite3_XXX functions enumerated
5948** above silently ignore any invocations that pass a NULL pointer instead
5949** of a valid mutex handle. The implementations of the methods defined
5950** by this structure are not required to handle this case, the results
5951** of passing a NULL pointer instead of a valid mutex handle are undefined
5952** (i.e. it is acceptable to provide an implementation that segfaults if
5953** it is passed a NULL pointer).
5954**
5955** The xMutexInit() method must be threadsafe.  ^It must be harmless to
5956** invoke xMutexInit() multiple times within the same process and without
5957** intervening calls to xMutexEnd().  Second and subsequent calls to
5958** xMutexInit() must be no-ops.
5959**
5960** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5961** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
5962** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
5963** memory allocation for a fast or recursive mutex.
5964**
5965** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5966** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5967** If xMutexInit fails in any way, it is expected to clean up after itself
5968** prior to returning.
5969*/
5970typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
5971struct sqlite3_mutex_methods {
5972  int (*xMutexInit)(void);
5973  int (*xMutexEnd)(void);
5974  sqlite3_mutex *(*xMutexAlloc)(int);
5975  void (*xMutexFree)(sqlite3_mutex *);
5976  void (*xMutexEnter)(sqlite3_mutex *);
5977  int (*xMutexTry)(sqlite3_mutex *);
5978  void (*xMutexLeave)(sqlite3_mutex *);
5979  int (*xMutexHeld)(sqlite3_mutex *);
5980  int (*xMutexNotheld)(sqlite3_mutex *);
5981};
5982
5983/*
5984** CAPI3REF: Mutex Verification Routines
5985**
5986** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5987** are intended for use inside assert() statements.  ^The SQLite core
5988** never uses these routines except inside an assert() and applications
5989** are advised to follow the lead of the core.  ^The SQLite core only
5990** provides implementations for these routines when it is compiled
5991** with the SQLITE_DEBUG flag.  ^External mutex implementations
5992** are only required to provide these routines if SQLITE_DEBUG is
5993** defined and if NDEBUG is not defined.
5994**
5995** ^These routines should return true if the mutex in their argument
5996** is held or not held, respectively, by the calling thread.
5997**
5998** ^The implementation is not required to provided versions of these
5999** routines that actually work. If the implementation does not provide working
6000** versions of these routines, it should at least provide stubs that always
6001** return true so that one does not get spurious assertion failures.
6002**
6003** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
6004** the routine should return 1.   This seems counter-intuitive since
6005** clearly the mutex cannot be held if it does not exist.  But
6006** the reason the mutex does not exist is because the build is not
6007** using mutexes.  And we do not want the assert() containing the
6008** call to sqlite3_mutex_held() to fail, so a non-zero return is
6009** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
6010** interface should also return 1 when given a NULL pointer.
6011*/
6012#ifndef NDEBUG
6013SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6014SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6015#endif
6016
6017/*
6018** CAPI3REF: Mutex Types
6019**
6020** The [sqlite3_mutex_alloc()] interface takes a single argument
6021** which is one of these integer constants.
6022**
6023** The set of static mutexes may change from one SQLite release to the
6024** next.  Applications that override the built-in mutex logic must be
6025** prepared to accommodate additional static mutexes.
6026*/
6027#define SQLITE_MUTEX_FAST             0
6028#define SQLITE_MUTEX_RECURSIVE        1
6029#define SQLITE_MUTEX_STATIC_MASTER    2
6030#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
6031#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
6032#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
6033#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
6034#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
6035#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
6036#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
6037
6038/*
6039** CAPI3REF: Retrieve the mutex for a database connection
6040**
6041** ^This interface returns a pointer the [sqlite3_mutex] object that
6042** serializes access to the [database connection] given in the argument
6043** when the [threading mode] is Serialized.
6044** ^If the [threading mode] is Single-thread or Multi-thread then this
6045** routine returns a NULL pointer.
6046*/
6047SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6048
6049/*
6050** CAPI3REF: Low-Level Control Of Database Files
6051**
6052** ^The [sqlite3_file_control()] interface makes a direct call to the
6053** xFileControl method for the [sqlite3_io_methods] object associated
6054** with a particular database identified by the second argument. ^The
6055** name of the database is "main" for the main database or "temp" for the
6056** TEMP database, or the name that appears after the AS keyword for
6057** databases that are added using the [ATTACH] SQL command.
6058** ^A NULL pointer can be used in place of "main" to refer to the
6059** main database file.
6060** ^The third and fourth parameters to this routine
6061** are passed directly through to the second and third parameters of
6062** the xFileControl method.  ^The return value of the xFileControl
6063** method becomes the return value of this routine.
6064**
6065** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6066** a pointer to the underlying [sqlite3_file] object to be written into
6067** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
6068** case is a short-circuit path which does not actually invoke the
6069** underlying sqlite3_io_methods.xFileControl method.
6070**
6071** ^If the second parameter (zDbName) does not match the name of any
6072** open database file, then SQLITE_ERROR is returned.  ^This error
6073** code is not remembered and will not be recalled by [sqlite3_errcode()]
6074** or [sqlite3_errmsg()].  The underlying xFileControl method might
6075** also return SQLITE_ERROR.  There is no way to distinguish between
6076** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6077** xFileControl method.
6078**
6079** See also: [SQLITE_FCNTL_LOCKSTATE]
6080*/
6081SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6082
6083/*
6084** CAPI3REF: Testing Interface
6085**
6086** ^The sqlite3_test_control() interface is used to read out internal
6087** state of SQLite and to inject faults into SQLite for testing
6088** purposes.  ^The first parameter is an operation code that determines
6089** the number, meaning, and operation of all subsequent parameters.
6090**
6091** This interface is not for use by applications.  It exists solely
6092** for verifying the correct operation of the SQLite library.  Depending
6093** on how the SQLite library is compiled, this interface might not exist.
6094**
6095** The details of the operation codes, their meanings, the parameters
6096** they take, and what they do are all subject to change without notice.
6097** Unlike most of the SQLite API, this function is not guaranteed to
6098** operate consistently from one release to the next.
6099*/
6100SQLITE_API int sqlite3_test_control(int op, ...);
6101
6102/*
6103** CAPI3REF: Testing Interface Operation Codes
6104**
6105** These constants are the valid operation code parameters used
6106** as the first argument to [sqlite3_test_control()].
6107**
6108** These parameters and their meanings are subject to change
6109** without notice.  These values are for testing purposes only.
6110** Applications should not use any of these parameters or the
6111** [sqlite3_test_control()] interface.
6112*/
6113#define SQLITE_TESTCTRL_FIRST                    5
6114#define SQLITE_TESTCTRL_PRNG_SAVE                5
6115#define SQLITE_TESTCTRL_PRNG_RESTORE             6
6116#define SQLITE_TESTCTRL_PRNG_RESET               7
6117#define SQLITE_TESTCTRL_BITVEC_TEST              8
6118#define SQLITE_TESTCTRL_FAULT_INSTALL            9
6119#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
6120#define SQLITE_TESTCTRL_PENDING_BYTE            11
6121#define SQLITE_TESTCTRL_ASSERT                  12
6122#define SQLITE_TESTCTRL_ALWAYS                  13
6123#define SQLITE_TESTCTRL_RESERVE                 14
6124#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
6125#define SQLITE_TESTCTRL_ISKEYWORD               16
6126#define SQLITE_TESTCTRL_PGHDRSZ                 17
6127#define SQLITE_TESTCTRL_SCRATCHMALLOC           18
6128#define SQLITE_TESTCTRL_LOCALTIME_FAULT         19
6129#define SQLITE_TESTCTRL_LAST                    19
6130
6131/*
6132** CAPI3REF: SQLite Runtime Status
6133**
6134** ^This interface is used to retrieve runtime status information
6135** about the performance of SQLite, and optionally to reset various
6136** highwater marks.  ^The first argument is an integer code for
6137** the specific parameter to measure.  ^(Recognized integer codes
6138** are of the form [status parameters | SQLITE_STATUS_...].)^
6139** ^The current value of the parameter is returned into *pCurrent.
6140** ^The highest recorded value is returned in *pHighwater.  ^If the
6141** resetFlag is true, then the highest record value is reset after
6142** *pHighwater is written.  ^(Some parameters do not record the highest
6143** value.  For those parameters
6144** nothing is written into *pHighwater and the resetFlag is ignored.)^
6145** ^(Other parameters record only the highwater mark and not the current
6146** value.  For these latter parameters nothing is written into *pCurrent.)^
6147**
6148** ^The sqlite3_status() routine returns SQLITE_OK on success and a
6149** non-zero [error code] on failure.
6150**
6151** This routine is threadsafe but is not atomic.  This routine can be
6152** called while other threads are running the same or different SQLite
6153** interfaces.  However the values returned in *pCurrent and
6154** *pHighwater reflect the status of SQLite at different points in time
6155** and it is possible that another thread might change the parameter
6156** in between the times when *pCurrent and *pHighwater are written.
6157**
6158** See also: [sqlite3_db_status()]
6159*/
6160SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6161
6162
6163/*
6164** CAPI3REF: Status Parameters
6165** KEYWORDS: {status parameters}
6166**
6167** These integer constants designate various run-time status parameters
6168** that can be returned by [sqlite3_status()].
6169**
6170** <dl>
6171** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6172** <dd>This parameter is the current amount of memory checked out
6173** using [sqlite3_malloc()], either directly or indirectly.  The
6174** figure includes calls made to [sqlite3_malloc()] by the application
6175** and internal memory usage by the SQLite library.  Scratch memory
6176** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6177** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6178** this parameter.  The amount returned is the sum of the allocation
6179** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6180**
6181** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6182** <dd>This parameter records the largest memory allocation request
6183** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6184** internal equivalents).  Only the value returned in the
6185** *pHighwater parameter to [sqlite3_status()] is of interest.
6186** The value written into the *pCurrent parameter is undefined.</dd>)^
6187**
6188** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6189** <dd>This parameter records the number of separate memory allocations
6190** currently checked out.</dd>)^
6191**
6192** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6193** <dd>This parameter returns the number of pages used out of the
6194** [pagecache memory allocator] that was configured using
6195** [SQLITE_CONFIG_PAGECACHE].  The
6196** value returned is in pages, not in bytes.</dd>)^
6197**
6198** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6199** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6200** <dd>This parameter returns the number of bytes of page cache
6201** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6202** buffer and where forced to overflow to [sqlite3_malloc()].  The
6203** returned value includes allocations that overflowed because they
6204** where too large (they were larger than the "sz" parameter to
6205** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6206** no space was left in the page cache.</dd>)^
6207**
6208** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6209** <dd>This parameter records the largest memory allocation request
6210** handed to [pagecache memory allocator].  Only the value returned in the
6211** *pHighwater parameter to [sqlite3_status()] is of interest.
6212** The value written into the *pCurrent parameter is undefined.</dd>)^
6213**
6214** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6215** <dd>This parameter returns the number of allocations used out of the
6216** [scratch memory allocator] configured using
6217** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
6218** in bytes.  Since a single thread may only have one scratch allocation
6219** outstanding at time, this parameter also reports the number of threads
6220** using scratch memory at the same time.</dd>)^
6221**
6222** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6223** <dd>This parameter returns the number of bytes of scratch memory
6224** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6225** buffer and where forced to overflow to [sqlite3_malloc()].  The values
6226** returned include overflows because the requested allocation was too
6227** larger (that is, because the requested allocation was larger than the
6228** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6229** slots were available.
6230** </dd>)^
6231**
6232** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6233** <dd>This parameter records the largest memory allocation request
6234** handed to [scratch memory allocator].  Only the value returned in the
6235** *pHighwater parameter to [sqlite3_status()] is of interest.
6236** The value written into the *pCurrent parameter is undefined.</dd>)^
6237**
6238** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6239** <dd>This parameter records the deepest parser stack.  It is only
6240** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6241** </dl>
6242**
6243** New status parameters may be added from time to time.
6244*/
6245#define SQLITE_STATUS_MEMORY_USED          0
6246#define SQLITE_STATUS_PAGECACHE_USED       1
6247#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
6248#define SQLITE_STATUS_SCRATCH_USED         3
6249#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
6250#define SQLITE_STATUS_MALLOC_SIZE          5
6251#define SQLITE_STATUS_PARSER_STACK         6
6252#define SQLITE_STATUS_PAGECACHE_SIZE       7
6253#define SQLITE_STATUS_SCRATCH_SIZE         8
6254#define SQLITE_STATUS_MALLOC_COUNT         9
6255
6256/*
6257** CAPI3REF: Database Connection Status
6258**
6259** ^This interface is used to retrieve runtime status information
6260** about a single [database connection].  ^The first argument is the
6261** database connection object to be interrogated.  ^The second argument
6262** is an integer constant, taken from the set of
6263** [SQLITE_DBSTATUS options], that
6264** determines the parameter to interrogate.  The set of
6265** [SQLITE_DBSTATUS options] is likely
6266** to grow in future releases of SQLite.
6267**
6268** ^The current value of the requested parameter is written into *pCur
6269** and the highest instantaneous value is written into *pHiwtr.  ^If
6270** the resetFlg is true, then the highest instantaneous value is
6271** reset back down to the current value.
6272**
6273** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6274** non-zero [error code] on failure.
6275**
6276** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6277*/
6278SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6279
6280/*
6281** CAPI3REF: Status Parameters for database connections
6282** KEYWORDS: {SQLITE_DBSTATUS options}
6283**
6284** These constants are the available integer "verbs" that can be passed as
6285** the second argument to the [sqlite3_db_status()] interface.
6286**
6287** New verbs may be added in future releases of SQLite. Existing verbs
6288** might be discontinued. Applications should check the return code from
6289** [sqlite3_db_status()] to make sure that the call worked.
6290** The [sqlite3_db_status()] interface will return a non-zero error code
6291** if a discontinued or unsupported verb is invoked.
6292**
6293** <dl>
6294** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6295** <dd>This parameter returns the number of lookaside memory slots currently
6296** checked out.</dd>)^
6297**
6298** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6299** <dd>This parameter returns the number malloc attempts that were
6300** satisfied using lookaside memory. Only the high-water value is meaningful;
6301** the current value is always zero.)^
6302**
6303** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6304** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6305** <dd>This parameter returns the number malloc attempts that might have
6306** been satisfied using lookaside memory but failed due to the amount of
6307** memory requested being larger than the lookaside slot size.
6308** Only the high-water value is meaningful;
6309** the current value is always zero.)^
6310**
6311** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6312** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6313** <dd>This parameter returns the number malloc attempts that might have
6314** been satisfied using lookaside memory but failed due to all lookaside
6315** memory already being in use.
6316** Only the high-water value is meaningful;
6317** the current value is always zero.)^
6318**
6319** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6320** <dd>This parameter returns the approximate number of of bytes of heap
6321** memory used by all pager caches associated with the database connection.)^
6322** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6323**
6324** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6325** <dd>This parameter returns the approximate number of of bytes of heap
6326** memory used to store the schema for all databases associated
6327** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6328** ^The full amount of memory used by the schemas is reported, even if the
6329** schema memory is shared with other database connections due to
6330** [shared cache mode] being enabled.
6331** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6332**
6333** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6334** <dd>This parameter returns the approximate number of of bytes of heap
6335** and lookaside memory used by all prepared statements associated with
6336** the database connection.)^
6337** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6338** </dd>
6339** </dl>
6340*/
6341#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
6342#define SQLITE_DBSTATUS_CACHE_USED           1
6343#define SQLITE_DBSTATUS_SCHEMA_USED          2
6344#define SQLITE_DBSTATUS_STMT_USED            3
6345#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
6346#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
6347#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
6348#define SQLITE_DBSTATUS_MAX                  6   /* Largest defined DBSTATUS */
6349
6350
6351/*
6352** CAPI3REF: Prepared Statement Status
6353**
6354** ^(Each prepared statement maintains various
6355** [SQLITE_STMTSTATUS counters] that measure the number
6356** of times it has performed specific operations.)^  These counters can
6357** be used to monitor the performance characteristics of the prepared
6358** statements.  For example, if the number of table steps greatly exceeds
6359** the number of table searches or result rows, that would tend to indicate
6360** that the prepared statement is using a full table scan rather than
6361** an index.
6362**
6363** ^(This interface is used to retrieve and reset counter values from
6364** a [prepared statement].  The first argument is the prepared statement
6365** object to be interrogated.  The second argument
6366** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6367** to be interrogated.)^
6368** ^The current value of the requested counter is returned.
6369** ^If the resetFlg is true, then the counter is reset to zero after this
6370** interface call returns.
6371**
6372** See also: [sqlite3_status()] and [sqlite3_db_status()].
6373*/
6374SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6375
6376/*
6377** CAPI3REF: Status Parameters for prepared statements
6378** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6379**
6380** These preprocessor macros define integer codes that name counter
6381** values associated with the [sqlite3_stmt_status()] interface.
6382** The meanings of the various counters are as follows:
6383**
6384** <dl>
6385** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6386** <dd>^This is the number of times that SQLite has stepped forward in
6387** a table as part of a full table scan.  Large numbers for this counter
6388** may indicate opportunities for performance improvement through
6389** careful use of indices.</dd>
6390**
6391** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6392** <dd>^This is the number of sort operations that have occurred.
6393** A non-zero value in this counter may indicate an opportunity to
6394** improvement performance through careful use of indices.</dd>
6395**
6396** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6397** <dd>^This is the number of rows inserted into transient indices that
6398** were created automatically in order to help joins run faster.
6399** A non-zero value in this counter may indicate an opportunity to
6400** improvement performance by adding permanent indices that do not
6401** need to be reinitialized each time the statement is run.</dd>
6402**
6403** </dl>
6404*/
6405#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
6406#define SQLITE_STMTSTATUS_SORT              2
6407#define SQLITE_STMTSTATUS_AUTOINDEX         3
6408
6409/*
6410** CAPI3REF: Custom Page Cache Object
6411**
6412** The sqlite3_pcache type is opaque.  It is implemented by
6413** the pluggable module.  The SQLite core has no knowledge of
6414** its size or internal structure and never deals with the
6415** sqlite3_pcache object except by holding and passing pointers
6416** to the object.
6417**
6418** See [sqlite3_pcache_methods] for additional information.
6419*/
6420typedef struct sqlite3_pcache sqlite3_pcache;
6421
6422/*
6423** CAPI3REF: Application Defined Page Cache.
6424** KEYWORDS: {page cache}
6425**
6426** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
6427** register an alternative page cache implementation by passing in an
6428** instance of the sqlite3_pcache_methods structure.)^
6429** In many applications, most of the heap memory allocated by
6430** SQLite is used for the page cache.
6431** By implementing a
6432** custom page cache using this API, an application can better control
6433** the amount of memory consumed by SQLite, the way in which
6434** that memory is allocated and released, and the policies used to
6435** determine exactly which parts of a database file are cached and for
6436** how long.
6437**
6438** The alternative page cache mechanism is an
6439** extreme measure that is only needed by the most demanding applications.
6440** The built-in page cache is recommended for most uses.
6441**
6442** ^(The contents of the sqlite3_pcache_methods structure are copied to an
6443** internal buffer by SQLite within the call to [sqlite3_config].  Hence
6444** the application may discard the parameter after the call to
6445** [sqlite3_config()] returns.)^
6446**
6447** [[the xInit() page cache method]]
6448** ^(The xInit() method is called once for each effective
6449** call to [sqlite3_initialize()])^
6450** (usually only once during the lifetime of the process). ^(The xInit()
6451** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
6452** The intent of the xInit() method is to set up global data structures
6453** required by the custom page cache implementation.
6454** ^(If the xInit() method is NULL, then the
6455** built-in default page cache is used instead of the application defined
6456** page cache.)^
6457**
6458** [[the xShutdown() page cache method]]
6459** ^The xShutdown() method is called by [sqlite3_shutdown()].
6460** It can be used to clean up
6461** any outstanding resources before process shutdown, if required.
6462** ^The xShutdown() method may be NULL.
6463**
6464** ^SQLite automatically serializes calls to the xInit method,
6465** so the xInit method need not be threadsafe.  ^The
6466** xShutdown method is only called from [sqlite3_shutdown()] so it does
6467** not need to be threadsafe either.  All other methods must be threadsafe
6468** in multithreaded applications.
6469**
6470** ^SQLite will never invoke xInit() more than once without an intervening
6471** call to xShutdown().
6472**
6473** [[the xCreate() page cache methods]]
6474** ^SQLite invokes the xCreate() method to construct a new cache instance.
6475** SQLite will typically create one cache instance for each open database file,
6476** though this is not guaranteed. ^The
6477** first parameter, szPage, is the size in bytes of the pages that must
6478** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
6479** will the page size of the database file that is to be cached plus an
6480** increment (here called "R") of less than 250.  SQLite will use the
6481** extra R bytes on each page to store metadata about the underlying
6482** database page on disk.  The value of R depends
6483** on the SQLite version, the target platform, and how SQLite was compiled.
6484** ^(R is constant for a particular build of SQLite. Except, there are two
6485** distinct values of R when SQLite is compiled with the proprietary
6486** ZIPVFS extension.)^  ^The second argument to
6487** xCreate(), bPurgeable, is true if the cache being created will
6488** be used to cache database pages of a file stored on disk, or
6489** false if it is used for an in-memory database. The cache implementation
6490** does not have to do anything special based with the value of bPurgeable;
6491** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
6492** never invoke xUnpin() except to deliberately delete a page.
6493** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6494** false will always have the "discard" flag set to true.
6495** ^Hence, a cache created with bPurgeable false will
6496** never contain any unpinned pages.
6497**
6498** [[the xCachesize() page cache method]]
6499** ^(The xCachesize() method may be called at any time by SQLite to set the
6500** suggested maximum cache-size (number of pages stored by) the cache
6501** instance passed as the first argument. This is the value configured using
6502** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
6503** parameter, the implementation is not required to do anything with this
6504** value; it is advisory only.
6505**
6506** [[the xPagecount() page cache methods]]
6507** The xPagecount() method must return the number of pages currently
6508** stored in the cache, both pinned and unpinned.
6509**
6510** [[the xFetch() page cache methods]]
6511** The xFetch() method locates a page in the cache and returns a pointer to
6512** the page, or a NULL pointer.
6513** A "page", in this context, means a buffer of szPage bytes aligned at an
6514** 8-byte boundary. The page to be fetched is determined by the key. ^The
6515** minimum key value is 1.  After it has been retrieved using xFetch, the page
6516** is considered to be "pinned".
6517**
6518** If the requested page is already in the page cache, then the page cache
6519** implementation must return a pointer to the page buffer with its content
6520** intact.  If the requested page is not already in the cache, then the
6521** cache implementation should use the value of the createFlag
6522** parameter to help it determined what action to take:
6523**
6524** <table border=1 width=85% align=center>
6525** <tr><th> createFlag <th> Behaviour when page is not already in cache
6526** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
6527** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6528**                 Otherwise return NULL.
6529** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
6530**                 NULL if allocating a new page is effectively impossible.
6531** </table>
6532**
6533** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
6534** will only use a createFlag of 2 after a prior call with a createFlag of 1
6535** failed.)^  In between the to xFetch() calls, SQLite may
6536** attempt to unpin one or more cache pages by spilling the content of
6537** pinned pages to disk and synching the operating system disk cache.
6538**
6539** [[the xUnpin() page cache method]]
6540** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6541** as its second argument.  If the third parameter, discard, is non-zero,
6542** then the page must be evicted from the cache.
6543** ^If the discard parameter is
6544** zero, then the page may be discarded or retained at the discretion of
6545** page cache implementation. ^The page cache implementation
6546** may choose to evict unpinned pages at any time.
6547**
6548** The cache must not perform any reference counting. A single
6549** call to xUnpin() unpins the page regardless of the number of prior calls
6550** to xFetch().
6551**
6552** [[the xRekey() page cache methods]]
6553** The xRekey() method is used to change the key value associated with the
6554** page passed as the second argument. If the cache
6555** previously contains an entry associated with newKey, it must be
6556** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6557** to be pinned.
6558**
6559** When SQLite calls the xTruncate() method, the cache must discard all
6560** existing cache entries with page numbers (keys) greater than or equal
6561** to the value of the iLimit parameter passed to xTruncate(). If any
6562** of these pages are pinned, they are implicitly unpinned, meaning that
6563** they can be safely discarded.
6564**
6565** [[the xDestroy() page cache method]]
6566** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6567** All resources associated with the specified cache should be freed. ^After
6568** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6569** handle invalid, and will not use it with any other sqlite3_pcache_methods
6570** functions.
6571*/
6572typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
6573struct sqlite3_pcache_methods {
6574  void *pArg;
6575  int (*xInit)(void*);
6576  void (*xShutdown)(void*);
6577  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6578  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6579  int (*xPagecount)(sqlite3_pcache*);
6580  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6581  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6582  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6583  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6584  void (*xDestroy)(sqlite3_pcache*);
6585};
6586
6587/*
6588** CAPI3REF: Online Backup Object
6589**
6590** The sqlite3_backup object records state information about an ongoing
6591** online backup operation.  ^The sqlite3_backup object is created by
6592** a call to [sqlite3_backup_init()] and is destroyed by a call to
6593** [sqlite3_backup_finish()].
6594**
6595** See Also: [Using the SQLite Online Backup API]
6596*/
6597typedef struct sqlite3_backup sqlite3_backup;
6598
6599/*
6600** CAPI3REF: Online Backup API.
6601**
6602** The backup API copies the content of one database into another.
6603** It is useful either for creating backups of databases or
6604** for copying in-memory databases to or from persistent files.
6605**
6606** See Also: [Using the SQLite Online Backup API]
6607**
6608** ^SQLite holds a write transaction open on the destination database file
6609** for the duration of the backup operation.
6610** ^The source database is read-locked only while it is being read;
6611** it is not locked continuously for the entire backup operation.
6612** ^Thus, the backup may be performed on a live source database without
6613** preventing other database connections from
6614** reading or writing to the source database while the backup is underway.
6615**
6616** ^(To perform a backup operation:
6617**   <ol>
6618**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
6619**         backup,
6620**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6621**         the data between the two databases, and finally
6622**     <li><b>sqlite3_backup_finish()</b> is called to release all resources
6623**         associated with the backup operation.
6624**   </ol>)^
6625** There should be exactly one call to sqlite3_backup_finish() for each
6626** successful call to sqlite3_backup_init().
6627**
6628** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6629**
6630** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6631** [database connection] associated with the destination database
6632** and the database name, respectively.
6633** ^The database name is "main" for the main database, "temp" for the
6634** temporary database, or the name specified after the AS keyword in
6635** an [ATTACH] statement for an attached database.
6636** ^The S and M arguments passed to
6637** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6638** and database name of the source database, respectively.
6639** ^The source and destination [database connections] (parameters S and D)
6640** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6641** an error.
6642**
6643** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6644** returned and an error code and error message are stored in the
6645** destination [database connection] D.
6646** ^The error code and message for the failed call to sqlite3_backup_init()
6647** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6648** [sqlite3_errmsg16()] functions.
6649** ^A successful call to sqlite3_backup_init() returns a pointer to an
6650** [sqlite3_backup] object.
6651** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6652** sqlite3_backup_finish() functions to perform the specified backup
6653** operation.
6654**
6655** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6656**
6657** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6658** the source and destination databases specified by [sqlite3_backup] object B.
6659** ^If N is negative, all remaining source pages are copied.
6660** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6661** are still more pages to be copied, then the function returns [SQLITE_OK].
6662** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6663** from source to destination, then it returns [SQLITE_DONE].
6664** ^If an error occurs while running sqlite3_backup_step(B,N),
6665** then an [error code] is returned. ^As well as [SQLITE_OK] and
6666** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6667** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6668** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6669**
6670** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6671** <ol>
6672** <li> the destination database was opened read-only, or
6673** <li> the destination database is using write-ahead-log journaling
6674** and the destination and source page sizes differ, or
6675** <li> the destination database is an in-memory database and the
6676** destination and source page sizes differ.
6677** </ol>)^
6678**
6679** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6680** the [sqlite3_busy_handler | busy-handler function]
6681** is invoked (if one is specified). ^If the
6682** busy-handler returns non-zero before the lock is available, then
6683** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6684** sqlite3_backup_step() can be retried later. ^If the source
6685** [database connection]
6686** is being used to write to the source database when sqlite3_backup_step()
6687** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6688** case the call to sqlite3_backup_step() can be retried later on. ^(If
6689** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6690** [SQLITE_READONLY] is returned, then
6691** there is no point in retrying the call to sqlite3_backup_step(). These
6692** errors are considered fatal.)^  The application must accept
6693** that the backup operation has failed and pass the backup operation handle
6694** to the sqlite3_backup_finish() to release associated resources.
6695**
6696** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6697** on the destination file. ^The exclusive lock is not released until either
6698** sqlite3_backup_finish() is called or the backup operation is complete
6699** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
6700** sqlite3_backup_step() obtains a [shared lock] on the source database that
6701** lasts for the duration of the sqlite3_backup_step() call.
6702** ^Because the source database is not locked between calls to
6703** sqlite3_backup_step(), the source database may be modified mid-way
6704** through the backup process.  ^If the source database is modified by an
6705** external process or via a database connection other than the one being
6706** used by the backup operation, then the backup will be automatically
6707** restarted by the next call to sqlite3_backup_step(). ^If the source
6708** database is modified by the using the same database connection as is used
6709** by the backup operation, then the backup database is automatically
6710** updated at the same time.
6711**
6712** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6713**
6714** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6715** application wishes to abandon the backup operation, the application
6716** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6717** ^The sqlite3_backup_finish() interfaces releases all
6718** resources associated with the [sqlite3_backup] object.
6719** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6720** active write-transaction on the destination database is rolled back.
6721** The [sqlite3_backup] object is invalid
6722** and may not be used following a call to sqlite3_backup_finish().
6723**
6724** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6725** sqlite3_backup_step() errors occurred, regardless or whether or not
6726** sqlite3_backup_step() completed.
6727** ^If an out-of-memory condition or IO error occurred during any prior
6728** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6729** sqlite3_backup_finish() returns the corresponding [error code].
6730**
6731** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6732** is not a permanent error and does not affect the return value of
6733** sqlite3_backup_finish().
6734**
6735** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6736** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6737**
6738** ^Each call to sqlite3_backup_step() sets two values inside
6739** the [sqlite3_backup] object: the number of pages still to be backed
6740** up and the total number of pages in the source database file.
6741** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6742** retrieve these two values, respectively.
6743**
6744** ^The values returned by these functions are only updated by
6745** sqlite3_backup_step(). ^If the source database is modified during a backup
6746** operation, then the values are not updated to account for any extra
6747** pages that need to be updated or the size of the source database file
6748** changing.
6749**
6750** <b>Concurrent Usage of Database Handles</b>
6751**
6752** ^The source [database connection] may be used by the application for other
6753** purposes while a backup operation is underway or being initialized.
6754** ^If SQLite is compiled and configured to support threadsafe database
6755** connections, then the source database connection may be used concurrently
6756** from within other threads.
6757**
6758** However, the application must guarantee that the destination
6759** [database connection] is not passed to any other API (by any thread) after
6760** sqlite3_backup_init() is called and before the corresponding call to
6761** sqlite3_backup_finish().  SQLite does not currently check to see
6762** if the application incorrectly accesses the destination [database connection]
6763** and so no error code is reported, but the operations may malfunction
6764** nevertheless.  Use of the destination database connection while a
6765** backup is in progress might also also cause a mutex deadlock.
6766**
6767** If running in [shared cache mode], the application must
6768** guarantee that the shared cache used by the destination database
6769** is not accessed while the backup is running. In practice this means
6770** that the application must guarantee that the disk file being
6771** backed up to is not accessed by any connection within the process,
6772** not just the specific connection that was passed to sqlite3_backup_init().
6773**
6774** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6775** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6776** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6777** APIs are not strictly speaking threadsafe. If they are invoked at the
6778** same time as another thread is invoking sqlite3_backup_step() it is
6779** possible that they return invalid values.
6780*/
6781SQLITE_API sqlite3_backup *sqlite3_backup_init(
6782  sqlite3 *pDest,                        /* Destination database handle */
6783  const char *zDestName,                 /* Destination database name */
6784  sqlite3 *pSource,                      /* Source database handle */
6785  const char *zSourceName                /* Source database name */
6786);
6787SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6788SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
6789SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
6790SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
6791
6792/*
6793** CAPI3REF: Unlock Notification
6794**
6795** ^When running in shared-cache mode, a database operation may fail with
6796** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6797** individual tables within the shared-cache cannot be obtained. See
6798** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
6799** ^This API may be used to register a callback that SQLite will invoke
6800** when the connection currently holding the required lock relinquishes it.
6801** ^This API is only available if the library was compiled with the
6802** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6803**
6804** See Also: [Using the SQLite Unlock Notification Feature].
6805**
6806** ^Shared-cache locks are released when a database connection concludes
6807** its current transaction, either by committing it or rolling it back.
6808**
6809** ^When a connection (known as the blocked connection) fails to obtain a
6810** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6811** identity of the database connection (the blocking connection) that
6812** has locked the required resource is stored internally. ^After an
6813** application receives an SQLITE_LOCKED error, it may call the
6814** sqlite3_unlock_notify() method with the blocked connection handle as
6815** the first argument to register for a callback that will be invoked
6816** when the blocking connections current transaction is concluded. ^The
6817** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6818** call that concludes the blocking connections transaction.
6819**
6820** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6821** there is a chance that the blocking connection will have already
6822** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6823** If this happens, then the specified callback is invoked immediately,
6824** from within the call to sqlite3_unlock_notify().)^
6825**
6826** ^If the blocked connection is attempting to obtain a write-lock on a
6827** shared-cache table, and more than one other connection currently holds
6828** a read-lock on the same table, then SQLite arbitrarily selects one of
6829** the other connections to use as the blocking connection.
6830**
6831** ^(There may be at most one unlock-notify callback registered by a
6832** blocked connection. If sqlite3_unlock_notify() is called when the
6833** blocked connection already has a registered unlock-notify callback,
6834** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6835** called with a NULL pointer as its second argument, then any existing
6836** unlock-notify callback is canceled. ^The blocked connections
6837** unlock-notify callback may also be canceled by closing the blocked
6838** connection using [sqlite3_close()].
6839**
6840** The unlock-notify callback is not reentrant. If an application invokes
6841** any sqlite3_xxx API functions from within an unlock-notify callback, a
6842** crash or deadlock may be the result.
6843**
6844** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6845** returns SQLITE_OK.
6846**
6847** <b>Callback Invocation Details</b>
6848**
6849** When an unlock-notify callback is registered, the application provides a
6850** single void* pointer that is passed to the callback when it is invoked.
6851** However, the signature of the callback function allows SQLite to pass
6852** it an array of void* context pointers. The first argument passed to
6853** an unlock-notify callback is a pointer to an array of void* pointers,
6854** and the second is the number of entries in the array.
6855**
6856** When a blocking connections transaction is concluded, there may be
6857** more than one blocked connection that has registered for an unlock-notify
6858** callback. ^If two or more such blocked connections have specified the
6859** same callback function, then instead of invoking the callback function
6860** multiple times, it is invoked once with the set of void* context pointers
6861** specified by the blocked connections bundled together into an array.
6862** This gives the application an opportunity to prioritize any actions
6863** related to the set of unblocked database connections.
6864**
6865** <b>Deadlock Detection</b>
6866**
6867** Assuming that after registering for an unlock-notify callback a
6868** database waits for the callback to be issued before taking any further
6869** action (a reasonable assumption), then using this API may cause the
6870** application to deadlock. For example, if connection X is waiting for
6871** connection Y's transaction to be concluded, and similarly connection
6872** Y is waiting on connection X's transaction, then neither connection
6873** will proceed and the system may remain deadlocked indefinitely.
6874**
6875** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
6876** detection. ^If a given call to sqlite3_unlock_notify() would put the
6877** system in a deadlocked state, then SQLITE_LOCKED is returned and no
6878** unlock-notify callback is registered. The system is said to be in
6879** a deadlocked state if connection A has registered for an unlock-notify
6880** callback on the conclusion of connection B's transaction, and connection
6881** B has itself registered for an unlock-notify callback when connection
6882** A's transaction is concluded. ^Indirect deadlock is also detected, so
6883** the system is also considered to be deadlocked if connection B has
6884** registered for an unlock-notify callback on the conclusion of connection
6885** C's transaction, where connection C is waiting on connection A. ^Any
6886** number of levels of indirection are allowed.
6887**
6888** <b>The "DROP TABLE" Exception</b>
6889**
6890** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
6891** always appropriate to call sqlite3_unlock_notify(). There is however,
6892** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
6893** SQLite checks if there are any currently executing SELECT statements
6894** that belong to the same connection. If there are, SQLITE_LOCKED is
6895** returned. In this case there is no "blocking connection", so invoking
6896** sqlite3_unlock_notify() results in the unlock-notify callback being
6897** invoked immediately. If the application then re-attempts the "DROP TABLE"
6898** or "DROP INDEX" query, an infinite loop might be the result.
6899**
6900** One way around this problem is to check the extended error code returned
6901** by an sqlite3_step() call. ^(If there is a blocking connection, then the
6902** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
6903** the special "DROP TABLE/INDEX" case, the extended error code is just
6904** SQLITE_LOCKED.)^
6905*/
6906SQLITE_API int sqlite3_unlock_notify(
6907  sqlite3 *pBlocked,                          /* Waiting connection */
6908  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
6909  void *pNotifyArg                            /* Argument to pass to xNotify */
6910);
6911
6912
6913/*
6914** CAPI3REF: String Comparison
6915**
6916** ^The [sqlite3_strnicmp()] API allows applications and extensions to
6917** compare the contents of two buffers containing UTF-8 strings in a
6918** case-independent fashion, using the same definition of case independence
6919** that SQLite uses internally when comparing identifiers.
6920*/
6921SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
6922
6923/*
6924** CAPI3REF: Error Logging Interface
6925**
6926** ^The [sqlite3_log()] interface writes a message into the error log
6927** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
6928** ^If logging is enabled, the zFormat string and subsequent arguments are
6929** used with [sqlite3_snprintf()] to generate the final output string.
6930**
6931** The sqlite3_log() interface is intended for use by extensions such as
6932** virtual tables, collating functions, and SQL functions.  While there is
6933** nothing to prevent an application from calling sqlite3_log(), doing so
6934** is considered bad form.
6935**
6936** The zFormat string must not be NULL.
6937**
6938** To avoid deadlocks and other threading problems, the sqlite3_log() routine
6939** will not use dynamically allocated memory.  The log message is stored in
6940** a fixed-length buffer on the stack.  If the log message is longer than
6941** a few hundred characters, it will be truncated to the length of the
6942** buffer.
6943*/
6944SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
6945
6946/*
6947** CAPI3REF: Write-Ahead Log Commit Hook
6948**
6949** ^The [sqlite3_wal_hook()] function is used to register a callback that
6950** will be invoked each time a database connection commits data to a
6951** [write-ahead log] (i.e. whenever a transaction is committed in
6952** [journal_mode | journal_mode=WAL mode]).
6953**
6954** ^The callback is invoked by SQLite after the commit has taken place and
6955** the associated write-lock on the database released, so the implementation
6956** may read, write or [checkpoint] the database as required.
6957**
6958** ^The first parameter passed to the callback function when it is invoked
6959** is a copy of the third parameter passed to sqlite3_wal_hook() when
6960** registering the callback. ^The second is a copy of the database handle.
6961** ^The third parameter is the name of the database that was written to -
6962** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
6963** is the number of pages currently in the write-ahead log file,
6964** including those that were just committed.
6965**
6966** The callback function should normally return [SQLITE_OK].  ^If an error
6967** code is returned, that error will propagate back up through the
6968** SQLite code base to cause the statement that provoked the callback
6969** to report an error, though the commit will have still occurred. If the
6970** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
6971** that does not correspond to any valid SQLite error code, the results
6972** are undefined.
6973**
6974** A single database handle may have at most a single write-ahead log callback
6975** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
6976** previously registered write-ahead log callback. ^Note that the
6977** [sqlite3_wal_autocheckpoint()] interface and the
6978** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
6979** those overwrite any prior [sqlite3_wal_hook()] settings.
6980*/
6981SQLITE_API void *sqlite3_wal_hook(
6982  sqlite3*,
6983  int(*)(void *,sqlite3*,const char*,int),
6984  void*
6985);
6986
6987/*
6988** CAPI3REF: Configure an auto-checkpoint
6989**
6990** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
6991** [sqlite3_wal_hook()] that causes any database on [database connection] D
6992** to automatically [checkpoint]
6993** after committing a transaction if there are N or
6994** more frames in the [write-ahead log] file.  ^Passing zero or
6995** a negative value as the nFrame parameter disables automatic
6996** checkpoints entirely.
6997**
6998** ^The callback registered by this function replaces any existing callback
6999** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
7000** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7001** configured by this function.
7002**
7003** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7004** from SQL.
7005**
7006** ^Every new [database connection] defaults to having the auto-checkpoint
7007** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7008** pages.  The use of this interface
7009** is only necessary if the default setting is found to be suboptimal
7010** for a particular application.
7011*/
7012SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7013
7014/*
7015** CAPI3REF: Checkpoint a database
7016**
7017** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
7018** on [database connection] D to be [checkpointed].  ^If X is NULL or an
7019** empty string, then a checkpoint is run on all databases of
7020** connection D.  ^If the database connection D is not in
7021** [WAL | write-ahead log mode] then this interface is a harmless no-op.
7022**
7023** ^The [wal_checkpoint pragma] can be used to invoke this interface
7024** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
7025** [wal_autocheckpoint pragma] can be used to cause this interface to be
7026** run whenever the WAL reaches a certain size threshold.
7027**
7028** See also: [sqlite3_wal_checkpoint_v2()]
7029*/
7030SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7031
7032/*
7033** CAPI3REF: Checkpoint a database
7034**
7035** Run a checkpoint operation on WAL database zDb attached to database
7036** handle db. The specific operation is determined by the value of the
7037** eMode parameter:
7038**
7039** <dl>
7040** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7041**   Checkpoint as many frames as possible without waiting for any database
7042**   readers or writers to finish. Sync the db file if all frames in the log
7043**   are checkpointed. This mode is the same as calling
7044**   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
7045**
7046** <dt>SQLITE_CHECKPOINT_FULL<dd>
7047**   This mode blocks (calls the busy-handler callback) until there is no
7048**   database writer and all readers are reading from the most recent database
7049**   snapshot. It then checkpoints all frames in the log file and syncs the
7050**   database file. This call blocks database writers while it is running,
7051**   but not database readers.
7052**
7053** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7054**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
7055**   checkpointing the log file it blocks (calls the busy-handler callback)
7056**   until all readers are reading from the database file only. This ensures
7057**   that the next client to write to the database file restarts the log file
7058**   from the beginning. This call blocks database writers while it is running,
7059**   but not database readers.
7060** </dl>
7061**
7062** If pnLog is not NULL, then *pnLog is set to the total number of frames in
7063** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
7064** the total number of checkpointed frames (including any that were already
7065** checkpointed when this function is called). *pnLog and *pnCkpt may be
7066** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
7067** If no values are available because of an error, they are both set to -1
7068** before returning to communicate this to the caller.
7069**
7070** All calls obtain an exclusive "checkpoint" lock on the database file. If
7071** any other process is running a checkpoint operation at the same time, the
7072** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
7073** busy-handler configured, it will not be invoked in this case.
7074**
7075** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
7076** "writer" lock on the database file. If the writer lock cannot be obtained
7077** immediately, and a busy-handler is configured, it is invoked and the writer
7078** lock retried until either the busy-handler returns 0 or the lock is
7079** successfully obtained. The busy-handler is also invoked while waiting for
7080** database readers as described above. If the busy-handler returns 0 before
7081** the writer lock is obtained or while waiting for database readers, the
7082** checkpoint operation proceeds from that point in the same way as
7083** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7084** without blocking any further. SQLITE_BUSY is returned in this case.
7085**
7086** If parameter zDb is NULL or points to a zero length string, then the
7087** specified operation is attempted on all WAL databases. In this case the
7088** values written to output parameters *pnLog and *pnCkpt are undefined. If
7089** an SQLITE_BUSY error is encountered when processing one or more of the
7090** attached WAL databases, the operation is still attempted on any remaining
7091** attached databases and SQLITE_BUSY is returned to the caller. If any other
7092** error occurs while processing an attached database, processing is abandoned
7093** and the error code returned to the caller immediately. If no error
7094** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7095** databases, SQLITE_OK is returned.
7096**
7097** If database zDb is the name of an attached database that is not in WAL
7098** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
7099** zDb is not NULL (or a zero length string) and is not the name of any
7100** attached database, SQLITE_ERROR is returned to the caller.
7101*/
7102SQLITE_API int sqlite3_wal_checkpoint_v2(
7103  sqlite3 *db,                    /* Database handle */
7104  const char *zDb,                /* Name of attached database (or NULL) */
7105  int eMode,                      /* SQLITE_CHECKPOINT_* value */
7106  int *pnLog,                     /* OUT: Size of WAL log in frames */
7107  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
7108);
7109
7110/*
7111** CAPI3REF: Checkpoint operation parameters
7112**
7113** These constants can be used as the 3rd parameter to
7114** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
7115** documentation for additional information about the meaning and use of
7116** each of these values.
7117*/
7118#define SQLITE_CHECKPOINT_PASSIVE 0
7119#define SQLITE_CHECKPOINT_FULL    1
7120#define SQLITE_CHECKPOINT_RESTART 2
7121
7122/*
7123** CAPI3REF: Virtual Table Interface Configuration
7124**
7125** This function may be called by either the [xConnect] or [xCreate] method
7126** of a [virtual table] implementation to configure
7127** various facets of the virtual table interface.
7128**
7129** If this interface is invoked outside the context of an xConnect or
7130** xCreate virtual table method then the behavior is undefined.
7131**
7132** At present, there is only one option that may be configured using
7133** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
7134** may be added in the future.
7135*/
7136SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
7137
7138/*
7139** CAPI3REF: Virtual Table Configuration Options
7140**
7141** These macros define the various options to the
7142** [sqlite3_vtab_config()] interface that [virtual table] implementations
7143** can use to customize and optimize their behavior.
7144**
7145** <dl>
7146** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
7147** <dd>Calls of the form
7148** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7149** where X is an integer.  If X is zero, then the [virtual table] whose
7150** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7151** support constraints.  In this configuration (which is the default) if
7152** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7153** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7154** specified as part of the users SQL statement, regardless of the actual
7155** ON CONFLICT mode specified.
7156**
7157** If X is non-zero, then the virtual table implementation guarantees
7158** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7159** any modifications to internal or persistent data structures have been made.
7160** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7161** is able to roll back a statement or database transaction, and abandon
7162** or continue processing the current SQL statement as appropriate.
7163** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7164** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7165** had been ABORT.
7166**
7167** Virtual table implementations that are required to handle OR REPLACE
7168** must do so within the [xUpdate] method. If a call to the
7169** [sqlite3_vtab_on_conflict()] function indicates that the current ON
7170** CONFLICT policy is REPLACE, the virtual table implementation should
7171** silently replace the appropriate rows within the xUpdate callback and
7172** return SQLITE_OK. Or, if this is not possible, it may return
7173** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
7174** constraint handling.
7175** </dl>
7176*/
7177#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
7178
7179/*
7180** CAPI3REF: Determine The Virtual Table Conflict Policy
7181**
7182** This function may only be called from within a call to the [xUpdate] method
7183** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7184** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7185** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7186** of the SQL statement that triggered the call to the [xUpdate] method of the
7187** [virtual table].
7188*/
7189SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
7190
7191/*
7192** CAPI3REF: Conflict resolution modes
7193**
7194** These constants are returned by [sqlite3_vtab_on_conflict()] to
7195** inform a [virtual table] implementation what the [ON CONFLICT] mode
7196** is for the SQL statement being evaluated.
7197**
7198** Note that the [SQLITE_IGNORE] constant is also used as a potential
7199** return value from the [sqlite3_set_authorizer()] callback and that
7200** [SQLITE_ABORT] is also a [result code].
7201*/
7202#define SQLITE_ROLLBACK 1
7203/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7204#define SQLITE_FAIL     3
7205/* #define SQLITE_ABORT 4  // Also an error code */
7206#define SQLITE_REPLACE  5
7207
7208
7209
7210/*
7211** Undo the hack that converts floating point types to integer for
7212** builds on processors without floating point support.
7213*/
7214#ifdef SQLITE_OMIT_FLOATING_POINT
7215# undef double
7216#endif
7217
7218#if 0
7219}  /* End of the 'extern "C"' block */
7220#endif
7221#endif
7222
7223/*
7224** 2010 August 30
7225**
7226** The author disclaims copyright to this source code.  In place of
7227** a legal notice, here is a blessing:
7228**
7229**    May you do good and not evil.
7230**    May you find forgiveness for yourself and forgive others.
7231**    May you share freely, never taking more than you give.
7232**
7233*************************************************************************
7234*/
7235
7236#ifndef _SQLITE3RTREE_H_
7237#define _SQLITE3RTREE_H_
7238
7239
7240#if 0
7241extern "C" {
7242#endif
7243
7244typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
7245
7246/*
7247** Register a geometry callback named zGeom that can be used as part of an
7248** R-Tree geometry query as follows:
7249**
7250**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
7251*/
7252SQLITE_API int sqlite3_rtree_geometry_callback(
7253  sqlite3 *db,
7254  const char *zGeom,
7255  int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
7256  void *pContext
7257);
7258
7259
7260/*
7261** A pointer to a structure of the following type is passed as the first
7262** argument to callbacks registered using rtree_geometry_callback().
7263*/
7264struct sqlite3_rtree_geometry {
7265  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
7266  int nParam;                     /* Size of array aParam[] */
7267  double *aParam;                 /* Parameters passed to SQL geom function */
7268  void *pUser;                    /* Callback implementation user data */
7269  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
7270};
7271
7272
7273#if 0
7274}  /* end of the 'extern "C"' block */
7275#endif
7276
7277#endif  /* ifndef _SQLITE3RTREE_H_ */
7278
7279
7280/************** End of sqlite3.h *********************************************/
7281/************** Continuing where we left off in sqliteInt.h ******************/
7282/************** Include hash.h in the middle of sqliteInt.h ******************/
7283/************** Begin file hash.h ********************************************/
7284/*
7285** 2001 September 22
7286**
7287** The author disclaims copyright to this source code.  In place of
7288** a legal notice, here is a blessing:
7289**
7290**    May you do good and not evil.
7291**    May you find forgiveness for yourself and forgive others.
7292**    May you share freely, never taking more than you give.
7293**
7294*************************************************************************
7295** This is the header file for the generic hash-table implemenation
7296** used in SQLite.
7297*/
7298#ifndef _SQLITE_HASH_H_
7299#define _SQLITE_HASH_H_
7300
7301/* Forward declarations of structures. */
7302typedef struct Hash Hash;
7303typedef struct HashElem HashElem;
7304
7305/* A complete hash table is an instance of the following structure.
7306** The internals of this structure are intended to be opaque -- client
7307** code should not attempt to access or modify the fields of this structure
7308** directly.  Change this structure only by using the routines below.
7309** However, some of the "procedures" and "functions" for modifying and
7310** accessing this structure are really macros, so we can't really make
7311** this structure opaque.
7312**
7313** All elements of the hash table are on a single doubly-linked list.
7314** Hash.first points to the head of this list.
7315**
7316** There are Hash.htsize buckets.  Each bucket points to a spot in
7317** the global doubly-linked list.  The contents of the bucket are the
7318** element pointed to plus the next _ht.count-1 elements in the list.
7319**
7320** Hash.htsize and Hash.ht may be zero.  In that case lookup is done
7321** by a linear search of the global list.  For small tables, the
7322** Hash.ht table is never allocated because if there are few elements
7323** in the table, it is faster to do a linear search than to manage
7324** the hash table.
7325*/
7326struct Hash {
7327  unsigned int htsize;      /* Number of buckets in the hash table */
7328  unsigned int count;       /* Number of entries in this table */
7329  HashElem *first;          /* The first element of the array */
7330  struct _ht {              /* the hash table */
7331    int count;                 /* Number of entries with this hash */
7332    HashElem *chain;           /* Pointer to first entry with this hash */
7333  } *ht;
7334};
7335
7336/* Each element in the hash table is an instance of the following
7337** structure.  All elements are stored on a single doubly-linked list.
7338**
7339** Again, this structure is intended to be opaque, but it can't really
7340** be opaque because it is used by macros.
7341*/
7342struct HashElem {
7343  HashElem *next, *prev;       /* Next and previous elements in the table */
7344  void *data;                  /* Data associated with this element */
7345  const char *pKey; int nKey;  /* Key associated with this element */
7346};
7347
7348/*
7349** Access routines.  To delete, insert a NULL pointer.
7350*/
7351SQLITE_PRIVATE void sqlite3HashInit(Hash*);
7352SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, int nKey, void *pData);
7353SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey, int nKey);
7354SQLITE_PRIVATE void sqlite3HashClear(Hash*);
7355
7356/*
7357** Macros for looping over all elements of a hash table.  The idiom is
7358** like this:
7359**
7360**   Hash h;
7361**   HashElem *p;
7362**   ...
7363**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
7364**     SomeStructure *pData = sqliteHashData(p);
7365**     // do something with pData
7366**   }
7367*/
7368#define sqliteHashFirst(H)  ((H)->first)
7369#define sqliteHashNext(E)   ((E)->next)
7370#define sqliteHashData(E)   ((E)->data)
7371/* #define sqliteHashKey(E)    ((E)->pKey) // NOT USED */
7372/* #define sqliteHashKeysize(E) ((E)->nKey)  // NOT USED */
7373
7374/*
7375** Number of entries in a hash table
7376*/
7377/* #define sqliteHashCount(H)  ((H)->count) // NOT USED */
7378
7379#endif /* _SQLITE_HASH_H_ */
7380
7381/************** End of hash.h ************************************************/
7382/************** Continuing where we left off in sqliteInt.h ******************/
7383/************** Include parse.h in the middle of sqliteInt.h *****************/
7384/************** Begin file parse.h *******************************************/
7385#define TK_SEMI                            1
7386#define TK_EXPLAIN                         2
7387#define TK_QUERY                           3
7388#define TK_PLAN                            4
7389#define TK_BEGIN                           5
7390#define TK_TRANSACTION                     6
7391#define TK_DEFERRED                        7
7392#define TK_IMMEDIATE                       8
7393#define TK_EXCLUSIVE                       9
7394#define TK_COMMIT                         10
7395#define TK_END                            11
7396#define TK_ROLLBACK                       12
7397#define TK_SAVEPOINT                      13
7398#define TK_RELEASE                        14
7399#define TK_TO                             15
7400#define TK_TABLE                          16
7401#define TK_CREATE                         17
7402#define TK_IF                             18
7403#define TK_NOT                            19
7404#define TK_EXISTS                         20
7405#define TK_TEMP                           21
7406#define TK_LP                             22
7407#define TK_RP                             23
7408#define TK_AS                             24
7409#define TK_COMMA                          25
7410#define TK_ID                             26
7411#define TK_INDEXED                        27
7412#define TK_ABORT                          28
7413#define TK_ACTION                         29
7414#define TK_AFTER                          30
7415#define TK_ANALYZE                        31
7416#define TK_ASC                            32
7417#define TK_ATTACH                         33
7418#define TK_BEFORE                         34
7419#define TK_BY                             35
7420#define TK_CASCADE                        36
7421#define TK_CAST                           37
7422#define TK_COLUMNKW                       38
7423#define TK_CONFLICT                       39
7424#define TK_DATABASE                       40
7425#define TK_DESC                           41
7426#define TK_DETACH                         42
7427#define TK_EACH                           43
7428#define TK_FAIL                           44
7429#define TK_FOR                            45
7430#define TK_IGNORE                         46
7431#define TK_INITIALLY                      47
7432#define TK_INSTEAD                        48
7433#define TK_LIKE_KW                        49
7434#define TK_MATCH                          50
7435#define TK_NO                             51
7436#define TK_KEY                            52
7437#define TK_OF                             53
7438#define TK_OFFSET                         54
7439#define TK_PRAGMA                         55
7440#define TK_RAISE                          56
7441#define TK_REPLACE                        57
7442#define TK_RESTRICT                       58
7443#define TK_ROW                            59
7444#define TK_TRIGGER                        60
7445#define TK_VACUUM                         61
7446#define TK_VIEW                           62
7447#define TK_VIRTUAL                        63
7448#define TK_REINDEX                        64
7449#define TK_RENAME                         65
7450#define TK_CTIME_KW                       66
7451#define TK_ANY                            67
7452#define TK_OR                             68
7453#define TK_AND                            69
7454#define TK_IS                             70
7455#define TK_BETWEEN                        71
7456#define TK_IN                             72
7457#define TK_ISNULL                         73
7458#define TK_NOTNULL                        74
7459#define TK_NE                             75
7460#define TK_EQ                             76
7461#define TK_GT                             77
7462#define TK_LE                             78
7463#define TK_LT                             79
7464#define TK_GE                             80
7465#define TK_ESCAPE                         81
7466#define TK_BITAND                         82
7467#define TK_BITOR                          83
7468#define TK_LSHIFT                         84
7469#define TK_RSHIFT                         85
7470#define TK_PLUS                           86
7471#define TK_MINUS                          87
7472#define TK_STAR                           88
7473#define TK_SLASH                          89
7474#define TK_REM                            90
7475#define TK_CONCAT                         91
7476#define TK_COLLATE                        92
7477#define TK_BITNOT                         93
7478#define TK_STRING                         94
7479#define TK_JOIN_KW                        95
7480#define TK_CONSTRAINT                     96
7481#define TK_DEFAULT                        97
7482#define TK_NULL                           98
7483#define TK_PRIMARY                        99
7484#define TK_UNIQUE                         100
7485#define TK_CHECK                          101
7486#define TK_REFERENCES                     102
7487#define TK_AUTOINCR                       103
7488#define TK_ON                             104
7489#define TK_INSERT                         105
7490#define TK_DELETE                         106
7491#define TK_UPDATE                         107
7492#define TK_SET                            108
7493#define TK_DEFERRABLE                     109
7494#define TK_FOREIGN                        110
7495#define TK_DROP                           111
7496#define TK_UNION                          112
7497#define TK_ALL                            113
7498#define TK_EXCEPT                         114
7499#define TK_INTERSECT                      115
7500#define TK_SELECT                         116
7501#define TK_DISTINCT                       117
7502#define TK_DOT                            118
7503#define TK_FROM                           119
7504#define TK_JOIN                           120
7505#define TK_USING                          121
7506#define TK_ORDER                          122
7507#define TK_GROUP                          123
7508#define TK_HAVING                         124
7509#define TK_LIMIT                          125
7510#define TK_WHERE                          126
7511#define TK_INTO                           127
7512#define TK_VALUES                         128
7513#define TK_INTEGER                        129
7514#define TK_FLOAT                          130
7515#define TK_BLOB                           131
7516#define TK_REGISTER                       132
7517#define TK_VARIABLE                       133
7518#define TK_CASE                           134
7519#define TK_WHEN                           135
7520#define TK_THEN                           136
7521#define TK_ELSE                           137
7522#define TK_INDEX                          138
7523#define TK_ALTER                          139
7524#define TK_ADD                            140
7525#define TK_TO_TEXT                        141
7526#define TK_TO_BLOB                        142
7527#define TK_TO_NUMERIC                     143
7528#define TK_TO_INT                         144
7529#define TK_TO_REAL                        145
7530#define TK_ISNOT                          146
7531#define TK_END_OF_FILE                    147
7532#define TK_ILLEGAL                        148
7533#define TK_SPACE                          149
7534#define TK_UNCLOSED_STRING                150
7535#define TK_FUNCTION                       151
7536#define TK_COLUMN                         152
7537#define TK_AGG_FUNCTION                   153
7538#define TK_AGG_COLUMN                     154
7539#define TK_CONST_FUNC                     155
7540#define TK_UMINUS                         156
7541#define TK_UPLUS                          157
7542
7543/************** End of parse.h ***********************************************/
7544/************** Continuing where we left off in sqliteInt.h ******************/
7545#include <stdio.h>
7546#include <stdlib.h>
7547#include <string.h>
7548#include <assert.h>
7549#include <stddef.h>
7550
7551/*
7552** If compiling for a processor that lacks floating point support,
7553** substitute integer for floating-point
7554*/
7555#ifdef SQLITE_OMIT_FLOATING_POINT
7556# define double sqlite_int64
7557# define float sqlite_int64
7558# define LONGDOUBLE_TYPE sqlite_int64
7559# ifndef SQLITE_BIG_DBL
7560#   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
7561# endif
7562# define SQLITE_OMIT_DATETIME_FUNCS 1
7563# define SQLITE_OMIT_TRACE 1
7564# undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
7565# undef SQLITE_HAVE_ISNAN
7566#endif
7567#ifndef SQLITE_BIG_DBL
7568# define SQLITE_BIG_DBL (1e99)
7569#endif
7570
7571/*
7572** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
7573** afterward. Having this macro allows us to cause the C compiler
7574** to omit code used by TEMP tables without messy #ifndef statements.
7575*/
7576#ifdef SQLITE_OMIT_TEMPDB
7577#define OMIT_TEMPDB 1
7578#else
7579#define OMIT_TEMPDB 0
7580#endif
7581
7582/*
7583** The "file format" number is an integer that is incremented whenever
7584** the VDBE-level file format changes.  The following macros define the
7585** the default file format for new databases and the maximum file format
7586** that the library can read.
7587*/
7588#define SQLITE_MAX_FILE_FORMAT 4
7589#ifndef SQLITE_DEFAULT_FILE_FORMAT
7590# define SQLITE_DEFAULT_FILE_FORMAT 1
7591#endif
7592
7593/*
7594** Determine whether triggers are recursive by default.  This can be
7595** changed at run-time using a pragma.
7596*/
7597#ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
7598# define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
7599#endif
7600
7601/*
7602** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
7603** on the command-line
7604*/
7605#ifndef SQLITE_TEMP_STORE
7606# define SQLITE_TEMP_STORE 1
7607#endif
7608
7609/*
7610** GCC does not define the offsetof() macro so we'll have to do it
7611** ourselves.
7612*/
7613#ifndef offsetof
7614#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
7615#endif
7616
7617/*
7618** Check to see if this machine uses EBCDIC.  (Yes, believe it or
7619** not, there are still machines out there that use EBCDIC.)
7620*/
7621#if 'A' == '\301'
7622# define SQLITE_EBCDIC 1
7623#else
7624# define SQLITE_ASCII 1
7625#endif
7626
7627/*
7628** Integers of known sizes.  These typedefs might change for architectures
7629** where the sizes very.  Preprocessor macros are available so that the
7630** types can be conveniently redefined at compile-type.  Like this:
7631**
7632**         cc '-DUINTPTR_TYPE=long long int' ...
7633*/
7634#ifndef UINT32_TYPE
7635# ifdef HAVE_UINT32_T
7636#  define UINT32_TYPE uint32_t
7637# else
7638#  define UINT32_TYPE unsigned int
7639# endif
7640#endif
7641#ifndef UINT16_TYPE
7642# ifdef HAVE_UINT16_T
7643#  define UINT16_TYPE uint16_t
7644# else
7645#  define UINT16_TYPE unsigned short int
7646# endif
7647#endif
7648#ifndef INT16_TYPE
7649# ifdef HAVE_INT16_T
7650#  define INT16_TYPE int16_t
7651# else
7652#  define INT16_TYPE short int
7653# endif
7654#endif
7655#ifndef UINT8_TYPE
7656# ifdef HAVE_UINT8_T
7657#  define UINT8_TYPE uint8_t
7658# else
7659#  define UINT8_TYPE unsigned char
7660# endif
7661#endif
7662#ifndef INT8_TYPE
7663# ifdef HAVE_INT8_T
7664#  define INT8_TYPE int8_t
7665# else
7666#  define INT8_TYPE signed char
7667# endif
7668#endif
7669#ifndef LONGDOUBLE_TYPE
7670# define LONGDOUBLE_TYPE long double
7671#endif
7672typedef sqlite_int64 i64;          /* 8-byte signed integer */
7673typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
7674typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
7675typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
7676typedef INT16_TYPE i16;            /* 2-byte signed integer */
7677typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
7678typedef INT8_TYPE i8;              /* 1-byte signed integer */
7679
7680/*
7681** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
7682** that can be stored in a u32 without loss of data.  The value
7683** is 0x00000000ffffffff.  But because of quirks of some compilers, we
7684** have to specify the value in the less intuitive manner shown:
7685*/
7686#define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
7687
7688/*
7689** Macros to determine whether the machine is big or little endian,
7690** evaluated at runtime.
7691*/
7692#ifdef SQLITE_AMALGAMATION
7693SQLITE_PRIVATE const int sqlite3one = 1;
7694#else
7695SQLITE_PRIVATE const int sqlite3one;
7696#endif
7697#if defined(i386) || defined(__i386__) || defined(_M_IX86)\
7698                             || defined(__x86_64) || defined(__x86_64__)
7699# define SQLITE_BIGENDIAN    0
7700# define SQLITE_LITTLEENDIAN 1
7701# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
7702#else
7703# define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
7704# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
7705# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
7706#endif
7707
7708/*
7709** Constants for the largest and smallest possible 64-bit signed integers.
7710** These macros are designed to work correctly on both 32-bit and 64-bit
7711** compilers.
7712*/
7713#define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
7714#define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
7715
7716/*
7717** Round up a number to the next larger multiple of 8.  This is used
7718** to force 8-byte alignment on 64-bit architectures.
7719*/
7720#define ROUND8(x)     (((x)+7)&~7)
7721
7722/*
7723** Round down to the nearest multiple of 8
7724*/
7725#define ROUNDDOWN8(x) ((x)&~7)
7726
7727/*
7728** Assert that the pointer X is aligned to an 8-byte boundary.  This
7729** macro is used only within assert() to verify that the code gets
7730** all alignment restrictions correct.
7731**
7732** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
7733** underlying malloc() implemention might return us 4-byte aligned
7734** pointers.  In that case, only verify 4-byte alignment.
7735*/
7736#ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
7737# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
7738#else
7739# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
7740#endif
7741
7742
7743/*
7744** An instance of the following structure is used to store the busy-handler
7745** callback for a given sqlite handle.
7746**
7747** The sqlite.busyHandler member of the sqlite struct contains the busy
7748** callback for the database handle. Each pager opened via the sqlite
7749** handle is passed a pointer to sqlite.busyHandler. The busy-handler
7750** callback is currently invoked only from within pager.c.
7751*/
7752typedef struct BusyHandler BusyHandler;
7753struct BusyHandler {
7754  int (*xFunc)(void *,int);  /* The busy callback */
7755  void *pArg;                /* First arg to busy callback */
7756  int nBusy;                 /* Incremented with each busy call */
7757};
7758
7759/*
7760** Name of the master database table.  The master database table
7761** is a special table that holds the names and attributes of all
7762** user tables and indices.
7763*/
7764#define MASTER_NAME       "sqlite_master"
7765#define TEMP_MASTER_NAME  "sqlite_temp_master"
7766
7767/*
7768** The root-page of the master database table.
7769*/
7770#define MASTER_ROOT       1
7771
7772/*
7773** The name of the schema table.
7774*/
7775#define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
7776
7777/*
7778** A convenience macro that returns the number of elements in
7779** an array.
7780*/
7781#define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
7782
7783/*
7784** The following value as a destructor means to use sqlite3DbFree().
7785** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
7786*/
7787#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
7788
7789/*
7790** When SQLITE_OMIT_WSD is defined, it means that the target platform does
7791** not support Writable Static Data (WSD) such as global and static variables.
7792** All variables must either be on the stack or dynamically allocated from
7793** the heap.  When WSD is unsupported, the variable declarations scattered
7794** throughout the SQLite code must become constants instead.  The SQLITE_WSD
7795** macro is used for this purpose.  And instead of referencing the variable
7796** directly, we use its constant as a key to lookup the run-time allocated
7797** buffer that holds real variable.  The constant is also the initializer
7798** for the run-time allocated buffer.
7799**
7800** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
7801** macros become no-ops and have zero performance impact.
7802*/
7803#ifdef SQLITE_OMIT_WSD
7804  #define SQLITE_WSD const
7805  #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
7806  #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
7807SQLITE_API   int sqlite3_wsd_init(int N, int J);
7808SQLITE_API   void *sqlite3_wsd_find(void *K, int L);
7809#else
7810  #define SQLITE_WSD
7811  #define GLOBAL(t,v) v
7812  #define sqlite3GlobalConfig sqlite3Config
7813#endif
7814
7815/*
7816** The following macros are used to suppress compiler warnings and to
7817** make it clear to human readers when a function parameter is deliberately
7818** left unused within the body of a function. This usually happens when
7819** a function is called via a function pointer. For example the
7820** implementation of an SQL aggregate step callback may not use the
7821** parameter indicating the number of arguments passed to the aggregate,
7822** if it knows that this is enforced elsewhere.
7823**
7824** When a function parameter is not used at all within the body of a function,
7825** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
7826** However, these macros may also be used to suppress warnings related to
7827** parameters that may or may not be used depending on compilation options.
7828** For example those parameters only used in assert() statements. In these
7829** cases the parameters are named as per the usual conventions.
7830*/
7831#define UNUSED_PARAMETER(x) (void)(x)
7832#define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
7833
7834/*
7835** Forward references to structures
7836*/
7837typedef struct AggInfo AggInfo;
7838typedef struct AuthContext AuthContext;
7839typedef struct AutoincInfo AutoincInfo;
7840typedef struct Bitvec Bitvec;
7841typedef struct CollSeq CollSeq;
7842typedef struct Column Column;
7843typedef struct Db Db;
7844typedef struct Schema Schema;
7845typedef struct Expr Expr;
7846typedef struct ExprList ExprList;
7847typedef struct ExprSpan ExprSpan;
7848typedef struct FKey FKey;
7849typedef struct FuncDestructor FuncDestructor;
7850typedef struct FuncDef FuncDef;
7851typedef struct FuncDefHash FuncDefHash;
7852typedef struct IdList IdList;
7853typedef struct Index Index;
7854typedef struct IndexSample IndexSample;
7855typedef struct KeyClass KeyClass;
7856typedef struct KeyInfo KeyInfo;
7857typedef struct Lookaside Lookaside;
7858typedef struct LookasideSlot LookasideSlot;
7859typedef struct Module Module;
7860typedef struct NameContext NameContext;
7861typedef struct Parse Parse;
7862typedef struct RowSet RowSet;
7863typedef struct