1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are suppose to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef _SQLITE3_H_ 34#define _SQLITE3_H_ 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52/* 53** These no-op macros are used in front of interfaces to mark those 54** interfaces as either deprecated or experimental. New applications 55** should not use deprecated interfaces - they are support for backwards 56** compatibility only. Application writers should be aware that 57** experimental interfaces are subject to change in point releases. 58** 59** These macros used to resolve to various kinds of compiler magic that 60** would generate warning messages when they were used. But that 61** compiler magic ended up generating such a flurry of bug reports 62** that we have taken it all out and gone back to using simple 63** noop macros. 64*/ 65#define SQLITE_DEPRECATED 66#define SQLITE_EXPERIMENTAL 67 68/* 69** Ensure these symbols were not defined by some previous header file. 70*/ 71#ifdef SQLITE_VERSION 72# undef SQLITE_VERSION 73#endif 74#ifdef SQLITE_VERSION_NUMBER 75# undef SQLITE_VERSION_NUMBER 76#endif 77 78/* 79** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> 80** 81** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 82** the sqlite3.h file specify the version of SQLite with which 83** that header file is associated. 84** 85** The "version" of SQLite is a string of the form "X.Y.Z". 86** The phrase "alpha" or "beta" might be appended after the Z. 87** The X value is major version number always 3 in SQLite3. 88** The X value only changes when backwards compatibility is 89** broken and we intend to never break backwards compatibility. 90** The Y value is the minor version number and only changes when 91** there are major feature enhancements that are forwards compatible 92** but not backwards compatible. 93** The Z value is the release number and is incremented with 94** each release but resets back to 0 whenever Y is incremented. 95** 96** The SQLITE_VERSION_NUMBER is an integer that is computed as 97** follows: 98** 99** <blockquote><pre> 100** SQLITE_VERSION_NUMBER = X*1000000 + Y*1000 + Z 101** </pre></blockquote> 102** 103** Since version 3.6.18, SQLite source code has been stored in the 104** <a href="http://www.fossil-scm.org/">fossil configuration management 105** system</a>. The SQLITE_SOURCE_ID 106** macro is a string which identifies a particular check-in of SQLite 107** within its configuration management system. The string contains the 108** date and time of the check-in (UTC) and an SHA1 hash of the entire 109** source tree. 110** 111** See also: [sqlite3_libversion()], 112** [sqlite3_libversion_number()], and [sqlite3_sourceid()]. 113** 114** Requirements: [H10011] [H10014] 115*/ 116#define SQLITE_VERSION "--VERS--" 117#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 118#define SQLITE_SOURCE_ID "--SOURCE-ID--" 119 120/* 121** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> 122** KEYWORDS: sqlite3_version 123** 124** These interfaces provide the same information as the [SQLITE_VERSION], 125** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] #defines in the header, 126** but are associated with the library instead of the header file. Cautious 127** programmers might include an assert in their application to verify that 128** sqlite3_libversion_number() always returns the value 129** [SQLITE_VERSION_NUMBER] and thus insure that the application is 130** compiled with matching library and header files. 131** 132** <blockquote><pre> 133** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 134** </pre></blockquote> 135** 136** The sqlite3_libversion() function returns the same information as is 137** in the sqlite3_version[] string constant. The function is provided 138** for use in DLLs since DLL users usually do not have direct access to string 139** constants within the DLL. Similarly, the sqlite3_sourceid() function 140** returns the same information as is in the [SQLITE_SOURCE_ID] #define of 141** the header file. 142** 143** Requirements: [H10021] [H10022] [H10023] 144*/ 145SQLITE_EXTERN const char sqlite3_version[]; 146const char *sqlite3_libversion(void); 147const char *sqlite3_sourceid(void); 148int sqlite3_libversion_number(void); 149 150/* 151** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> 152** 153** SQLite can be compiled with or without mutexes. When 154** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 155** are enabled and SQLite is threadsafe. When the 156** [SQLITE_THREADSAFE] macro is 0, 157** the mutexes are omitted. Without the mutexes, it is not safe 158** to use SQLite concurrently from more than one thread. 159** 160** Enabling mutexes incurs a measurable performance penalty. 161** So if speed is of utmost importance, it makes sense to disable 162** the mutexes. But for maximum safety, mutexes should be enabled. 163** The default behavior is for mutexes to be enabled. 164** 165** This interface can be used by an application to make sure that the 166** version of SQLite that it is linking against was compiled with 167** the desired setting of the [SQLITE_THREADSAFE] macro. 168** 169** This interface only reports on the compile-time mutex setting 170** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 171** SQLITE_THREADSAFE=1 then mutexes are enabled by default but 172** can be fully or partially disabled using a call to [sqlite3_config()] 173** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 174** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows 175** only the default compile-time setting, not any run-time changes 176** to that setting. 177** 178** See the [threading mode] documentation for additional information. 179** 180** Requirements: [H10101] [H10102] 181*/ 182int sqlite3_threadsafe(void); 183 184/* 185** CAPI3REF: Database Connection Handle {H12000} <S40200> 186** KEYWORDS: {database connection} {database connections} 187** 188** Each open SQLite database is represented by a pointer to an instance of 189** the opaque structure named "sqlite3". It is useful to think of an sqlite3 190** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 191** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 192** is its destructor. There are many other interfaces (such as 193** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 194** [sqlite3_busy_timeout()] to name but three) that are methods on an 195** sqlite3 object. 196*/ 197typedef struct sqlite3 sqlite3; 198 199/* 200** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> 201** KEYWORDS: sqlite_int64 sqlite_uint64 202** 203** Because there is no cross-platform way to specify 64-bit integer types 204** SQLite includes typedefs for 64-bit signed and unsigned integers. 205** 206** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 207** The sqlite_int64 and sqlite_uint64 types are supported for backwards 208** compatibility only. 209** 210** Requirements: [H10201] [H10202] 211*/ 212#ifdef SQLITE_INT64_TYPE 213 typedef SQLITE_INT64_TYPE sqlite_int64; 214 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 215#elif defined(_MSC_VER) || defined(__BORLANDC__) 216 typedef __int64 sqlite_int64; 217 typedef unsigned __int64 sqlite_uint64; 218#else 219 typedef long long int sqlite_int64; 220 typedef unsigned long long int sqlite_uint64; 221#endif 222typedef sqlite_int64 sqlite3_int64; 223typedef sqlite_uint64 sqlite3_uint64; 224 225/* 226** If compiling for a processor that lacks floating point support, 227** substitute integer for floating-point. 228*/ 229#ifdef SQLITE_OMIT_FLOATING_POINT 230# define double sqlite3_int64 231#endif 232 233/* 234** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> 235** 236** This routine is the destructor for the [sqlite3] object. 237** 238** Applications should [sqlite3_finalize | finalize] all [prepared statements] 239** and [sqlite3_blob_close | close] all [BLOB handles] associated with 240** the [sqlite3] object prior to attempting to close the object. 241** The [sqlite3_next_stmt()] interface can be used to locate all 242** [prepared statements] associated with a [database connection] if desired. 243** Typical code might look like this: 244** 245** <blockquote><pre> 246** sqlite3_stmt *pStmt; 247** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ 248** sqlite3_finalize(pStmt); 249** } 250** </pre></blockquote> 251** 252** If [sqlite3_close()] is invoked while a transaction is open, 253** the transaction is automatically rolled back. 254** 255** The C parameter to [sqlite3_close(C)] must be either a NULL 256** pointer or an [sqlite3] object pointer obtained 257** from [sqlite3_open()], [sqlite3_open16()], or 258** [sqlite3_open_v2()], and not previously closed. 259** 260** Requirements: 261** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] 262*/ 263int sqlite3_close(sqlite3 *); 264 265/* 266** The type for a callback function. 267** This is legacy and deprecated. It is included for historical 268** compatibility and is not documented. 269*/ 270typedef int (*sqlite3_callback)(void*,int,char**, char**); 271 272/* 273** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> 274** 275** The sqlite3_exec() interface is a convenient way of running one or more 276** SQL statements without having to write a lot of C code. The UTF-8 encoded 277** SQL statements are passed in as the second parameter to sqlite3_exec(). 278** The statements are evaluated one by one until either an error or 279** an interrupt is encountered, or until they are all done. The 3rd parameter 280** is an optional callback that is invoked once for each row of any query 281** results produced by the SQL statements. The 5th parameter tells where 282** to write any error messages. 283** 284** The error message passed back through the 5th parameter is held 285** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, 286** the calling application should call [sqlite3_free()] on any error 287** message returned through the 5th parameter when it has finished using 288** the error message. 289** 290** If the SQL statement in the 2nd parameter is NULL or an empty string 291** or a string containing only whitespace and comments, then no SQL 292** statements are evaluated and the database is not changed. 293** 294** The sqlite3_exec() interface is implemented in terms of 295** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 296** The sqlite3_exec() routine does nothing to the database that cannot be done 297** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 298** 299** The first parameter to [sqlite3_exec()] must be an valid and open 300** [database connection]. 301** 302** The database connection must not be closed while 303** [sqlite3_exec()] is running. 304** 305** The calling function should use [sqlite3_free()] to free 306** the memory that *errmsg is left pointing at once the error 307** message is no longer needed. 308** 309** The SQL statement text in the 2nd parameter to [sqlite3_exec()] 310** must remain unchanged while [sqlite3_exec()] is running. 311** 312** Requirements: 313** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] 314** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] 315*/ 316int sqlite3_exec( 317 sqlite3*, /* An open database */ 318 const char *sql, /* SQL to be evaluated */ 319 int (*callback)(void*,int,char**,char**), /* Callback function */ 320 void *, /* 1st argument to callback */ 321 char **errmsg /* Error msg written here */ 322); 323 324/* 325** CAPI3REF: Result Codes {H10210} <S10700> 326** KEYWORDS: SQLITE_OK {error code} {error codes} 327** KEYWORDS: {result code} {result codes} 328** 329** Many SQLite functions return an integer result code from the set shown 330** here in order to indicates success or failure. 331** 332** New error codes may be added in future versions of SQLite. 333** 334** See also: [SQLITE_IOERR_READ | extended result codes] 335*/ 336#define SQLITE_OK 0 /* Successful result */ 337/* beginning-of-error-codes */ 338#define SQLITE_ERROR 1 /* SQL error or missing database */ 339#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 340#define SQLITE_PERM 3 /* Access permission denied */ 341#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 342#define SQLITE_BUSY 5 /* The database file is locked */ 343#define SQLITE_LOCKED 6 /* A table in the database is locked */ 344#define SQLITE_NOMEM 7 /* A malloc() failed */ 345#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 346#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 347#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 348#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 349#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 350#define SQLITE_FULL 13 /* Insertion failed because database is full */ 351#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 352#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 353#define SQLITE_EMPTY 16 /* Database is empty */ 354#define SQLITE_SCHEMA 17 /* The database schema changed */ 355#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 356#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 357#define SQLITE_MISMATCH 20 /* Data type mismatch */ 358#define SQLITE_MISUSE 21 /* Library used incorrectly */ 359#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 360#define SQLITE_AUTH 23 /* Authorization denied */ 361#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 362#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 363#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 364#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 365#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 366/* end-of-error-codes */ 367 368/* 369** CAPI3REF: Extended Result Codes {H10220} <S10700> 370** KEYWORDS: {extended error code} {extended error codes} 371** KEYWORDS: {extended result code} {extended result codes} 372** 373** In its default configuration, SQLite API routines return one of 26 integer 374** [SQLITE_OK | result codes]. However, experience has shown that many of 375** these result codes are too coarse-grained. They do not provide as 376** much information about problems as programmers might like. In an effort to 377** address this, newer versions of SQLite (version 3.3.8 and later) include 378** support for additional result codes that provide more detailed information 379** about errors. The extended result codes are enabled or disabled 380** on a per database connection basis using the 381** [sqlite3_extended_result_codes()] API. 382** 383** Some of the available extended result codes are listed here. 384** One may expect the number of extended result codes will be expand 385** over time. Software that uses extended result codes should expect 386** to see new result codes in future releases of SQLite. 387** 388** The SQLITE_OK result code will never be extended. It will always 389** be exactly zero. 390*/ 391#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 392#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 393#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 394#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 395#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 396#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 397#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 398#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 399#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 400#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 401#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 402#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 403#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 404#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 405#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 406#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 407#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 408#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) 409 410/* 411** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> 412** 413** These bit values are intended for use in the 414** 3rd parameter to the [sqlite3_open_v2()] interface and 415** in the 4th parameter to the xOpen method of the 416** [sqlite3_vfs] object. 417*/ 418#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 419#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 420#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 421#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 422#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 423#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 424#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 425#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 426#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 427#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 428#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 429#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 430#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 431#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 432 433/* 434** CAPI3REF: Device Characteristics {H10240} <H11120> 435** 436** The xDeviceCapabilities method of the [sqlite3_io_methods] 437** object returns an integer which is a vector of the these 438** bit values expressing I/O characteristics of the mass storage 439** device that holds the file that the [sqlite3_io_methods] 440** refers to. 441** 442** The SQLITE_IOCAP_ATOMIC property means that all writes of 443** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 444** mean that writes of blocks that are nnn bytes in size and 445** are aligned to an address which is an integer multiple of 446** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 447** that when data is appended to a file, the data is appended 448** first then the size of the file is extended, never the other 449** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 450** information is written to disk in the same order as calls 451** to xWrite(). 452*/ 453#define SQLITE_IOCAP_ATOMIC 0x00000001 454#define SQLITE_IOCAP_ATOMIC512 0x00000002 455#define SQLITE_IOCAP_ATOMIC1K 0x00000004 456#define SQLITE_IOCAP_ATOMIC2K 0x00000008 457#define SQLITE_IOCAP_ATOMIC4K 0x00000010 458#define SQLITE_IOCAP_ATOMIC8K 0x00000020 459#define SQLITE_IOCAP_ATOMIC16K 0x00000040 460#define SQLITE_IOCAP_ATOMIC32K 0x00000080 461#define SQLITE_IOCAP_ATOMIC64K 0x00000100 462#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 463#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 464 465/* 466** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> 467** 468** SQLite uses one of these integer values as the second 469** argument to calls it makes to the xLock() and xUnlock() methods 470** of an [sqlite3_io_methods] object. 471*/ 472#define SQLITE_LOCK_NONE 0 473#define SQLITE_LOCK_SHARED 1 474#define SQLITE_LOCK_RESERVED 2 475#define SQLITE_LOCK_PENDING 3 476#define SQLITE_LOCK_EXCLUSIVE 4 477 478/* 479** CAPI3REF: Synchronization Type Flags {H10260} <H11120> 480** 481** When SQLite invokes the xSync() method of an 482** [sqlite3_io_methods] object it uses a combination of 483** these integer values as the second argument. 484** 485** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 486** sync operation only needs to flush data to mass storage. Inode 487** information need not be flushed. If the lower four bits of the flag 488** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 489** If the lower four bits equal SQLITE_SYNC_FULL, that means 490** to use Mac OS X style fullsync instead of fsync(). 491*/ 492#define SQLITE_SYNC_NORMAL 0x00002 493#define SQLITE_SYNC_FULL 0x00003 494#define SQLITE_SYNC_DATAONLY 0x00010 495 496/* 497** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> 498** 499** An [sqlite3_file] object represents an open file in the 500** [sqlite3_vfs | OS interface layer]. Individual OS interface 501** implementations will 502** want to subclass this object by appending additional fields 503** for their own use. The pMethods entry is a pointer to an 504** [sqlite3_io_methods] object that defines methods for performing 505** I/O operations on the open file. 506*/ 507typedef struct sqlite3_file sqlite3_file; 508struct sqlite3_file { 509 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 510}; 511 512/* 513** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> 514** 515** Every file opened by the [sqlite3_vfs] xOpen method populates an 516** [sqlite3_file] object (or, more commonly, a subclass of the 517** [sqlite3_file] object) with a pointer to an instance of this object. 518** This object defines the methods used to perform various operations 519** against the open file represented by the [sqlite3_file] object. 520** 521** If the xOpen method sets the sqlite3_file.pMethods element 522** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 523** may be invoked even if the xOpen reported that it failed. The 524** only way to prevent a call to xClose following a failed xOpen 525** is for the xOpen to set the sqlite3_file.pMethods element to NULL. 526** 527** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 528** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 529** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 530** flag may be ORed in to indicate that only the data of the file 531** and not its inode needs to be synced. 532** 533** The integer values to xLock() and xUnlock() are one of 534** <ul> 535** <li> [SQLITE_LOCK_NONE], 536** <li> [SQLITE_LOCK_SHARED], 537** <li> [SQLITE_LOCK_RESERVED], 538** <li> [SQLITE_LOCK_PENDING], or 539** <li> [SQLITE_LOCK_EXCLUSIVE]. 540** </ul> 541** xLock() increases the lock. xUnlock() decreases the lock. 542** The xCheckReservedLock() method checks whether any database connection, 543** either in this process or in some other process, is holding a RESERVED, 544** PENDING, or EXCLUSIVE lock on the file. It returns true 545** if such a lock exists and false otherwise. 546** 547** The xFileControl() method is a generic interface that allows custom 548** VFS implementations to directly control an open file using the 549** [sqlite3_file_control()] interface. The second "op" argument is an 550** integer opcode. The third argument is a generic pointer intended to 551** point to a structure that may contain arguments or space in which to 552** write return values. Potential uses for xFileControl() might be 553** functions to enable blocking locks with timeouts, to change the 554** locking strategy (for example to use dot-file locks), to inquire 555** about the status of a lock, or to break stale locks. The SQLite 556** core reserves all opcodes less than 100 for its own use. 557** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 558** Applications that define a custom xFileControl method should use opcodes 559** greater than 100 to avoid conflicts. 560** 561** The xSectorSize() method returns the sector size of the 562** device that underlies the file. The sector size is the 563** minimum write that can be performed without disturbing 564** other bytes in the file. The xDeviceCharacteristics() 565** method returns a bit vector describing behaviors of the 566** underlying device: 567** 568** <ul> 569** <li> [SQLITE_IOCAP_ATOMIC] 570** <li> [SQLITE_IOCAP_ATOMIC512] 571** <li> [SQLITE_IOCAP_ATOMIC1K] 572** <li> [SQLITE_IOCAP_ATOMIC2K] 573** <li> [SQLITE_IOCAP_ATOMIC4K] 574** <li> [SQLITE_IOCAP_ATOMIC8K] 575** <li> [SQLITE_IOCAP_ATOMIC16K] 576** <li> [SQLITE_IOCAP_ATOMIC32K] 577** <li> [SQLITE_IOCAP_ATOMIC64K] 578** <li> [SQLITE_IOCAP_SAFE_APPEND] 579** <li> [SQLITE_IOCAP_SEQUENTIAL] 580** </ul> 581** 582** The SQLITE_IOCAP_ATOMIC property means that all writes of 583** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 584** mean that writes of blocks that are nnn bytes in size and 585** are aligned to an address which is an integer multiple of 586** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 587** that when data is appended to a file, the data is appended 588** first then the size of the file is extended, never the other 589** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 590** information is written to disk in the same order as calls 591** to xWrite(). 592** 593** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 594** in the unread portions of the buffer with zeros. A VFS that 595** fails to zero-fill short reads might seem to work. However, 596** failure to zero-fill short reads will eventually lead to 597** database corruption. 598*/ 599typedef struct sqlite3_io_methods sqlite3_io_methods; 600struct sqlite3_io_methods { 601 int iVersion; 602 int (*xClose)(sqlite3_file*); 603 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 604 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 605 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 606 int (*xSync)(sqlite3_file*, int flags); 607 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 608 int (*xLock)(sqlite3_file*, int); 609 int (*xUnlock)(sqlite3_file*, int); 610 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 611 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 612 int (*xSectorSize)(sqlite3_file*); 613 int (*xDeviceCharacteristics)(sqlite3_file*); 614 /* Additional methods may be added in future releases */ 615}; 616 617/* 618** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> 619** 620** These integer constants are opcodes for the xFileControl method 621** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 622** interface. 623** 624** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 625** opcode causes the xFileControl method to write the current state of 626** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 627** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 628** into an integer that the pArg argument points to. This capability 629** is used during testing and only needs to be supported when SQLITE_TEST 630** is defined. 631*/ 632#define SQLITE_FCNTL_LOCKSTATE 1 633#define SQLITE_GET_LOCKPROXYFILE 2 634#define SQLITE_SET_LOCKPROXYFILE 3 635#define SQLITE_LAST_ERRNO 4 636 637/* 638** CAPI3REF: Mutex Handle {H17110} <S20130> 639** 640** The mutex module within SQLite defines [sqlite3_mutex] to be an 641** abstract type for a mutex object. The SQLite core never looks 642** at the internal representation of an [sqlite3_mutex]. It only 643** deals with pointers to the [sqlite3_mutex] object. 644** 645** Mutexes are created using [sqlite3_mutex_alloc()]. 646*/ 647typedef struct sqlite3_mutex sqlite3_mutex; 648 649/* 650** CAPI3REF: OS Interface Object {H11140} <S20100> 651** 652** An instance of the sqlite3_vfs object defines the interface between 653** the SQLite core and the underlying operating system. The "vfs" 654** in the name of the object stands for "virtual file system". 655** 656** The value of the iVersion field is initially 1 but may be larger in 657** future versions of SQLite. Additional fields may be appended to this 658** object when the iVersion value is increased. Note that the structure 659** of the sqlite3_vfs object changes in the transaction between 660** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 661** modified. 662** 663** The szOsFile field is the size of the subclassed [sqlite3_file] 664** structure used by this VFS. mxPathname is the maximum length of 665** a pathname in this VFS. 666** 667** Registered sqlite3_vfs objects are kept on a linked list formed by 668** the pNext pointer. The [sqlite3_vfs_register()] 669** and [sqlite3_vfs_unregister()] interfaces manage this list 670** in a thread-safe way. The [sqlite3_vfs_find()] interface 671** searches the list. Neither the application code nor the VFS 672** implementation should use the pNext pointer. 673** 674** The pNext field is the only field in the sqlite3_vfs 675** structure that SQLite will ever modify. SQLite will only access 676** or modify this field while holding a particular static mutex. 677** The application should never modify anything within the sqlite3_vfs 678** object once the object has been registered. 679** 680** The zName field holds the name of the VFS module. The name must 681** be unique across all VFS modules. 682** 683** SQLite will guarantee that the zFilename parameter to xOpen 684** is either a NULL pointer or string obtained 685** from xFullPathname(). SQLite further guarantees that 686** the string will be valid and unchanged until xClose() is 687** called. Because of the previous sentence, 688** the [sqlite3_file] can safely store a pointer to the 689** filename if it needs to remember the filename for some reason. 690** If the zFilename parameter is xOpen is a NULL pointer then xOpen 691** must invent its own temporary name for the file. Whenever the 692** xFilename parameter is NULL it will also be the case that the 693** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 694** 695** The flags argument to xOpen() includes all bits set in 696** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 697** or [sqlite3_open16()] is used, then flags includes at least 698** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 699** If xOpen() opens a file read-only then it sets *pOutFlags to 700** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 701** 702** SQLite will also add one of the following flags to the xOpen() 703** call, depending on the object being opened: 704** 705** <ul> 706** <li> [SQLITE_OPEN_MAIN_DB] 707** <li> [SQLITE_OPEN_MAIN_JOURNAL] 708** <li> [SQLITE_OPEN_TEMP_DB] 709** <li> [SQLITE_OPEN_TEMP_JOURNAL] 710** <li> [SQLITE_OPEN_TRANSIENT_DB] 711** <li> [SQLITE_OPEN_SUBJOURNAL] 712** <li> [SQLITE_OPEN_MASTER_JOURNAL] 713** </ul> 714** 715** The file I/O implementation can use the object type flags to 716** change the way it deals with files. For example, an application 717** that does not care about crash recovery or rollback might make 718** the open of a journal file a no-op. Writes to this journal would 719** also be no-ops, and any attempt to read the journal would return 720** SQLITE_IOERR. Or the implementation might recognize that a database 721** file will be doing page-aligned sector reads and writes in a random 722** order and set up its I/O subsystem accordingly. 723** 724** SQLite might also add one of the following flags to the xOpen method: 725** 726** <ul> 727** <li> [SQLITE_OPEN_DELETEONCLOSE] 728** <li> [SQLITE_OPEN_EXCLUSIVE] 729** </ul> 730** 731** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 732** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] 733** will be set for TEMP databases, journals and for subjournals. 734** 735** The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 736** with the [SQLITE_OPEN_CREATE] flag, which are both directly 737** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 738** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 739** SQLITE_OPEN_CREATE, is used to indicate that file should always 740** be created, and that it is an error if it already exists. 741** It is <i>not</i> used to indicate the file should be opened 742** for exclusive access. 743** 744** At least szOsFile bytes of memory are allocated by SQLite 745** to hold the [sqlite3_file] structure passed as the third 746** argument to xOpen. The xOpen method does not have to 747** allocate the structure; it should just fill it in. Note that 748** the xOpen method must set the sqlite3_file.pMethods to either 749** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 750** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 751** element will be valid after xOpen returns regardless of the success 752** or failure of the xOpen call. 753** 754** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 755** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 756** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 757** to test whether a file is at least readable. The file can be a 758** directory. 759** 760** SQLite will always allocate at least mxPathname+1 bytes for the 761** output buffer xFullPathname. The exact size of the output buffer 762** is also passed as a parameter to both methods. If the output buffer 763** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 764** handled as a fatal error by SQLite, vfs implementations should endeavor 765** to prevent this by setting mxPathname to a sufficiently large value. 766** 767** The xRandomness(), xSleep(), and xCurrentTime() interfaces 768** are not strictly a part of the filesystem, but they are 769** included in the VFS structure for completeness. 770** The xRandomness() function attempts to return nBytes bytes 771** of good-quality randomness into zOut. The return value is 772** the actual number of bytes of randomness obtained. 773** The xSleep() method causes the calling thread to sleep for at 774** least the number of microseconds given. The xCurrentTime() 775** method returns a Julian Day Number for the current date and time. 776** 777*/ 778typedef struct sqlite3_vfs sqlite3_vfs; 779struct sqlite3_vfs { 780 int iVersion; /* Structure version number */ 781 int szOsFile; /* Size of subclassed sqlite3_file */ 782 int mxPathname; /* Maximum file pathname length */ 783 sqlite3_vfs *pNext; /* Next registered VFS */ 784 const char *zName; /* Name of this virtual file system */ 785 void *pAppData; /* Pointer to application-specific data */ 786 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 787 int flags, int *pOutFlags); 788 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 789 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 790 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 791 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 792 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 793 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 794 void (*xDlClose)(sqlite3_vfs*, void*); 795 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 796 int (*xSleep)(sqlite3_vfs*, int microseconds); 797 int (*xCurrentTime)(sqlite3_vfs*, double*); 798 int (*xGetLastError)(sqlite3_vfs*, int, char *); 799 /* New fields may be appended in figure versions. The iVersion 800 ** value will increment whenever this happens. */ 801}; 802 803/* 804** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> 805** 806** These integer constants can be used as the third parameter to 807** the xAccess method of an [sqlite3_vfs] object. {END} They determine 808** what kind of permissions the xAccess method is looking for. 809** With SQLITE_ACCESS_EXISTS, the xAccess method 810** simply checks whether the file exists. 811** With SQLITE_ACCESS_READWRITE, the xAccess method 812** checks whether the file is both readable and writable. 813** With SQLITE_ACCESS_READ, the xAccess method 814** checks whether the file is readable. 815*/ 816#define SQLITE_ACCESS_EXISTS 0 817#define SQLITE_ACCESS_READWRITE 1 818#define SQLITE_ACCESS_READ 2 819 820/* 821** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> 822** 823** The sqlite3_initialize() routine initializes the 824** SQLite library. The sqlite3_shutdown() routine 825** deallocates any resources that were allocated by sqlite3_initialize(). 826** 827** A call to sqlite3_initialize() is an "effective" call if it is 828** the first time sqlite3_initialize() is invoked during the lifetime of 829** the process, or if it is the first time sqlite3_initialize() is invoked 830** following a call to sqlite3_shutdown(). Only an effective call 831** of sqlite3_initialize() does any initialization. All other calls 832** are harmless no-ops. 833** 834** A call to sqlite3_shutdown() is an "effective" call if it is the first 835** call to sqlite3_shutdown() since the last sqlite3_initialize(). Only 836** an effective call to sqlite3_shutdown() does any deinitialization. 837** All other calls to sqlite3_shutdown() are harmless no-ops. 838** 839** Among other things, sqlite3_initialize() shall invoke 840** sqlite3_os_init(). Similarly, sqlite3_shutdown() 841** shall invoke sqlite3_os_end(). 842** 843** The sqlite3_initialize() routine returns [SQLITE_OK] on success. 844** If for some reason, sqlite3_initialize() is unable to initialize 845** the library (perhaps it is unable to allocate a needed resource such 846** as a mutex) it returns an [error code] other than [SQLITE_OK]. 847** 848** The sqlite3_initialize() routine is called internally by many other 849** SQLite interfaces so that an application usually does not need to 850** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 851** calls sqlite3_initialize() so the SQLite library will be automatically 852** initialized when [sqlite3_open()] is called if it has not be initialized 853** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 854** compile-time option, then the automatic calls to sqlite3_initialize() 855** are omitted and the application must call sqlite3_initialize() directly 856** prior to using any other SQLite interface. For maximum portability, 857** it is recommended that applications always invoke sqlite3_initialize() 858** directly prior to using any other SQLite interface. Future releases 859** of SQLite may require this. In other words, the behavior exhibited 860** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 861** default behavior in some future release of SQLite. 862** 863** The sqlite3_os_init() routine does operating-system specific 864** initialization of the SQLite library. The sqlite3_os_end() 865** routine undoes the effect of sqlite3_os_init(). Typical tasks 866** performed by these routines include allocation or deallocation 867** of static resources, initialization of global variables, 868** setting up a default [sqlite3_vfs] module, or setting up 869** a default configuration using [sqlite3_config()]. 870** 871** The application should never invoke either sqlite3_os_init() 872** or sqlite3_os_end() directly. The application should only invoke 873** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 874** interface is called automatically by sqlite3_initialize() and 875** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 876** implementations for sqlite3_os_init() and sqlite3_os_end() 877** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 878** When [custom builds | built for other platforms] 879** (using the [SQLITE_OS_OTHER=1] compile-time 880** option) the application must supply a suitable implementation for 881** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 882** implementation of sqlite3_os_init() or sqlite3_os_end() 883** must return [SQLITE_OK] on success and some other [error code] upon 884** failure. 885*/ 886int sqlite3_initialize(void); 887int sqlite3_shutdown(void); 888int sqlite3_os_init(void); 889int sqlite3_os_end(void); 890 891/* 892** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> 893** EXPERIMENTAL 894** 895** The sqlite3_config() interface is used to make global configuration 896** changes to SQLite in order to tune SQLite to the specific needs of 897** the application. The default configuration is recommended for most 898** applications and so this routine is usually not necessary. It is 899** provided to support rare applications with unusual needs. 900** 901** The sqlite3_config() interface is not threadsafe. The application 902** must insure that no other SQLite interfaces are invoked by other 903** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 904** may only be invoked prior to library initialization using 905** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 906** Note, however, that sqlite3_config() can be called as part of the 907** implementation of an application-defined [sqlite3_os_init()]. 908** 909** The first argument to sqlite3_config() is an integer 910** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 911** what property of SQLite is to be configured. Subsequent arguments 912** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 913** in the first argument. 914** 915** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 916** If the option is unknown or SQLite is unable to set the option 917** then this routine returns a non-zero [error code]. 918** 919** Requirements: 920** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] 921** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] 922** [H14162] [H14165] [H14168] 923*/ 924SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); 925 926/* 927** CAPI3REF: Configure database connections {H14200} <S20000> 928** EXPERIMENTAL 929** 930** The sqlite3_db_config() interface is used to make configuration 931** changes to a [database connection]. The interface is similar to 932** [sqlite3_config()] except that the changes apply to a single 933** [database connection] (specified in the first argument). The 934** sqlite3_db_config() interface can only be used immediately after 935** the database connection is created using [sqlite3_open()], 936** [sqlite3_open16()], or [sqlite3_open_v2()]. 937** 938** The second argument to sqlite3_db_config(D,V,...) is the 939** configuration verb - an integer code that indicates what 940** aspect of the [database connection] is being configured. 941** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. 942** New verbs are likely to be added in future releases of SQLite. 943** Additional arguments depend on the verb. 944** 945** Requirements: 946** [H14203] [H14206] [H14209] [H14212] [H14215] 947*/ 948SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); 949 950/* 951** CAPI3REF: Memory Allocation Routines {H10155} <S20120> 952** EXPERIMENTAL 953** 954** An instance of this object defines the interface between SQLite 955** and low-level memory allocation routines. 956** 957** This object is used in only one place in the SQLite interface. 958** A pointer to an instance of this object is the argument to 959** [sqlite3_config()] when the configuration option is 960** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 961** By creating an instance of this object 962** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 963** during configuration, an application can specify an alternative 964** memory allocation subsystem for SQLite to use for all of its 965** dynamic memory needs. 966** 967** Note that SQLite comes with several [built-in memory allocators] 968** that are perfectly adequate for the overwhelming majority of applications 969** and that this object is only useful to a tiny minority of applications 970** with specialized memory allocation requirements. This object is 971** also used during testing of SQLite in order to specify an alternative 972** memory allocator that simulates memory out-of-memory conditions in 973** order to verify that SQLite recovers gracefully from such 974** conditions. 975** 976** The xMalloc and xFree methods must work like the 977** malloc() and free() functions from the standard C library. 978** The xRealloc method must work like realloc() from the standard C library 979** with the exception that if the second argument to xRealloc is zero, 980** xRealloc must be a no-op - it must not perform any allocation or 981** deallocation. SQLite guaranteeds that the second argument to 982** xRealloc is always a value returned by a prior call to xRoundup. 983** And so in cases where xRoundup always returns a positive number, 984** xRealloc can perform exactly as the standard library realloc() and 985** still be in compliance with this specification. 986** 987** xSize should return the allocated size of a memory allocation 988** previously obtained from xMalloc or xRealloc. The allocated size 989** is always at least as big as the requested size but may be larger. 990** 991** The xRoundup method returns what would be the allocated size of 992** a memory allocation given a particular requested size. Most memory 993** allocators round up memory allocations at least to the next multiple 994** of 8. Some allocators round up to a larger multiple or to a power of 2. 995** Every memory allocation request coming in through [sqlite3_malloc()] 996** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 997** that causes the corresponding memory allocation to fail. 998** 999** The xInit method initializes the memory allocator. (For example, 1000** it might allocate any require mutexes or initialize internal data 1001** structures. The xShutdown method is invoked (indirectly) by 1002** [sqlite3_shutdown()] and should deallocate any resources acquired 1003** by xInit. The pAppData pointer is used as the only parameter to 1004** xInit and xShutdown. 1005** 1006** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1007** the xInit method, so the xInit method need not be threadsafe. The 1008** xShutdown method is only called from [sqlite3_shutdown()] so it does 1009** not need to be threadsafe either. For all other methods, SQLite 1010** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1011** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1012** it is by default) and so the methods are automatically serialized. 1013** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1014** methods must be threadsafe or else make their own arrangements for 1015** serialization. 1016** 1017** SQLite will never invoke xInit() more than once without an intervening 1018** call to xShutdown(). 1019*/ 1020typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1021struct sqlite3_mem_methods { 1022 void *(*xMalloc)(int); /* Memory allocation function */ 1023 void (*xFree)(void*); /* Free a prior allocation */ 1024 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1025 int (*xSize)(void*); /* Return the size of an allocation */ 1026 int (*xRoundup)(int); /* Round up request size to allocation size */ 1027 int (*xInit)(void*); /* Initialize the memory allocator */ 1028 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1029 void *pAppData; /* Argument to xInit() and xShutdown() */ 1030}; 1031 1032/* 1033** CAPI3REF: Configuration Options {H10160} <S20000> 1034** EXPERIMENTAL 1035** 1036** These constants are the available integer configuration options that 1037** can be passed as the first argument to the [sqlite3_config()] interface. 1038** 1039** New configuration options may be added in future releases of SQLite. 1040** Existing configuration options might be discontinued. Applications 1041** should check the return code from [sqlite3_config()] to make sure that 1042** the call worked. The [sqlite3_config()] interface will return a 1043** non-zero [error code] if a discontinued or unsupported configuration option 1044** is invoked. 1045** 1046** <dl> 1047** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1048** <dd>There are no arguments to this option. This option disables 1049** all mutexing and puts SQLite into a mode where it can only be used 1050** by a single thread.</dd> 1051** 1052** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1053** <dd>There are no arguments to this option. This option disables 1054** mutexing on [database connection] and [prepared statement] objects. 1055** The application is responsible for serializing access to 1056** [database connections] and [prepared statements]. But other mutexes 1057** are enabled so that SQLite will be safe to use in a multi-threaded 1058** environment as long as no two threads attempt to use the same 1059** [database connection] at the same time. See the [threading mode] 1060** documentation for additional information.</dd> 1061** 1062** <dt>SQLITE_CONFIG_SERIALIZED</dt> 1063** <dd>There are no arguments to this option. This option enables 1064** all mutexes including the recursive 1065** mutexes on [database connection] and [prepared statement] objects. 1066** In this mode (which is the default when SQLite is compiled with 1067** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1068** to [database connections] and [prepared statements] so that the 1069** application is free to use the same [database connection] or the 1070** same [prepared statement] in different threads at the same time. 1071** See the [threading mode] documentation for additional information.</dd> 1072** 1073** <dt>SQLITE_CONFIG_MALLOC</dt> 1074** <dd>This option takes a single argument which is a pointer to an 1075** instance of the [sqlite3_mem_methods] structure. The argument specifies 1076** alternative low-level memory allocation routines to be used in place of 1077** the memory allocation routines built into SQLite.</dd> 1078** 1079** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1080** <dd>This option takes a single argument which is a pointer to an 1081** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1082** structure is filled with the currently defined memory allocation routines. 1083** This option can be used to overload the default memory allocation 1084** routines with a wrapper that simulations memory allocation failure or 1085** tracks memory usage, for example.</dd> 1086** 1087** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1088** <dd>This option takes single argument of type int, interpreted as a 1089** boolean, which enables or disables the collection of memory allocation 1090** statistics. When disabled, the following SQLite interfaces become 1091** non-operational: 1092** <ul> 1093** <li> [sqlite3_memory_used()] 1094** <li> [sqlite3_memory_highwater()] 1095** <li> [sqlite3_soft_heap_limit()] 1096** <li> [sqlite3_status()] 1097** </ul> 1098** </dd> 1099** 1100** <dt>SQLITE_CONFIG_SCRATCH</dt> 1101** <dd>This option specifies a static memory buffer that SQLite can use for 1102** scratch memory. There are three arguments: A pointer an 8-byte 1103** aligned memory buffer from which the scrach allocations will be 1104** drawn, the size of each scratch allocation (sz), 1105** and the maximum number of scratch allocations (N). The sz 1106** argument must be a multiple of 16. The sz parameter should be a few bytes 1107** larger than the actual scratch space required due to internal overhead. 1108** The first argument should pointer to an 8-byte aligned buffer 1109** of at least sz*N bytes of memory. 1110** SQLite will use no more than one scratch buffer at once per thread, so 1111** N should be set to the expected maximum number of threads. The sz 1112** parameter should be 6 times the size of the largest database page size. 1113** Scratch buffers are used as part of the btree balance operation. If 1114** The btree balancer needs additional memory beyond what is provided by 1115** scratch buffers or if no scratch buffer space is specified, then SQLite 1116** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> 1117** 1118** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1119** <dd>This option specifies a static memory buffer that SQLite can use for 1120** the database page cache with the default page cache implemenation. 1121** This configuration should not be used if an application-define page 1122** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1123** There are three arguments to this option: A pointer to 8-byte aligned 1124** memory, the size of each page buffer (sz), and the number of pages (N). 1125** The sz argument should be the size of the largest database page 1126** (a power of two between 512 and 32768) plus a little extra for each 1127** page header. The page header size is 20 to 40 bytes depending on 1128** the host architecture. It is harmless, apart from the wasted memory, 1129** to make sz a little too large. The first 1130** argument should point to an allocation of at least sz*N bytes of memory. 1131** SQLite will use the memory provided by the first argument to satisfy its 1132** memory needs for the first N pages that it adds to cache. If additional 1133** page cache memory is needed beyond what is provided by this option, then 1134** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1135** The implementation might use one or more of the N buffers to hold 1136** memory accounting information. The pointer in the first argument must 1137** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1138** will be undefined.</dd> 1139** 1140** <dt>SQLITE_CONFIG_HEAP</dt> 1141** <dd>This option specifies a static memory buffer that SQLite will use 1142** for all of its dynamic memory allocation needs beyond those provided 1143** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1144** There are three arguments: An 8-byte aligned pointer to the memory, 1145** the number of bytes in the memory buffer, and the minimum allocation size. 1146** If the first pointer (the memory pointer) is NULL, then SQLite reverts 1147** to using its default memory allocator (the system malloc() implementation), 1148** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the 1149** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1150** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1151** allocator is engaged to handle all of SQLites memory allocation needs. 1152** The first pointer (the memory pointer) must be aligned to an 8-byte 1153** boundary or subsequent behavior of SQLite will be undefined.</dd> 1154** 1155** <dt>SQLITE_CONFIG_MUTEX</dt> 1156** <dd>This option takes a single argument which is a pointer to an 1157** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1158** alternative low-level mutex routines to be used in place 1159** the mutex routines built into SQLite.</dd> 1160** 1161** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1162** <dd>This option takes a single argument which is a pointer to an 1163** instance of the [sqlite3_mutex_methods] structure. The 1164** [sqlite3_mutex_methods] 1165** structure is filled with the currently defined mutex routines. 1166** This option can be used to overload the default mutex allocation 1167** routines with a wrapper used to track mutex usage for performance 1168** profiling or testing, for example.</dd> 1169** 1170** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1171** <dd>This option takes two arguments that determine the default 1172** memory allocation lookaside optimization. The first argument is the 1173** size of each lookaside buffer slot and the second is the number of 1174** slots allocated to each database connection. This option sets the 1175** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1176** verb to [sqlite3_db_config()] can be used to change the lookaside 1177** configuration on individual connections.</dd> 1178** 1179** <dt>SQLITE_CONFIG_PCACHE</dt> 1180** <dd>This option takes a single argument which is a pointer to 1181** an [sqlite3_pcache_methods] object. This object specifies the interface 1182** to a custom page cache implementation. SQLite makes a copy of the 1183** object and uses it for page cache memory allocations.</dd> 1184** 1185** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1186** <dd>This option takes a single argument which is a pointer to an 1187** [sqlite3_pcache_methods] object. SQLite copies of the current 1188** page cache implementation into that object.</dd> 1189** 1190** </dl> 1191*/ 1192#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1193#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1194#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1195#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1196#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1197#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1198#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1199#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1200#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1201#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1202#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1203/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1204#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1205#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1206#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1207 1208/* 1209** CAPI3REF: Configuration Options {H10170} <S20000> 1210** EXPERIMENTAL 1211** 1212** These constants are the available integer configuration options that 1213** can be passed as the second argument to the [sqlite3_db_config()] interface. 1214** 1215** New configuration options may be added in future releases of SQLite. 1216** Existing configuration options might be discontinued. Applications 1217** should check the return code from [sqlite3_db_config()] to make sure that 1218** the call worked. The [sqlite3_db_config()] interface will return a 1219** non-zero [error code] if a discontinued or unsupported configuration option 1220** is invoked. 1221** 1222** <dl> 1223** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1224** <dd>This option takes three additional arguments that determine the 1225** [lookaside memory allocator] configuration for the [database connection]. 1226** The first argument (the third parameter to [sqlite3_db_config()] is a 1227** pointer to an memory buffer to use for lookaside memory. 1228** The first argument may be NULL in which case SQLite will allocate the 1229** lookaside buffer itself using [sqlite3_malloc()]. The second argument is the 1230** size of each lookaside buffer slot and the third argument is the number of 1231** slots. The size of the buffer in the first argument must be greater than 1232** or equal to the product of the second and third arguments. The buffer 1233** must be aligned to an 8-byte boundary. If the second argument is not 1234** a multiple of 8, it is internally rounded down to the next smaller 1235** multiple of 8. See also: [SQLITE_CONFIG_LOOKASIDE]</dd> 1236** 1237** </dl> 1238*/ 1239#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1240 1241 1242/* 1243** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> 1244** 1245** The sqlite3_extended_result_codes() routine enables or disables the 1246** [extended result codes] feature of SQLite. The extended result 1247** codes are disabled by default for historical compatibility considerations. 1248** 1249** Requirements: 1250** [H12201] [H12202] 1251*/ 1252int sqlite3_extended_result_codes(sqlite3*, int onoff); 1253 1254/* 1255** CAPI3REF: Last Insert Rowid {H12220} <S10700> 1256** 1257** Each entry in an SQLite table has a unique 64-bit signed 1258** integer key called the [ROWID | "rowid"]. The rowid is always available 1259** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1260** names are not also used by explicitly declared columns. If 1261** the table has a column of type [INTEGER PRIMARY KEY] then that column 1262** is another alias for the rowid. 1263** 1264** This routine returns the [rowid] of the most recent 1265** successful [INSERT] into the database from the [database connection] 1266** in the first argument. If no successful [INSERT]s 1267** have ever occurred on that database connection, zero is returned. 1268** 1269** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1270** row is returned by this routine as long as the trigger is running. 1271** But once the trigger terminates, the value returned by this routine 1272** reverts to the last value inserted before the trigger fired. 1273** 1274** An [INSERT] that fails due to a constraint violation is not a 1275** successful [INSERT] and does not change the value returned by this 1276** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1277** and INSERT OR ABORT make no changes to the return value of this 1278** routine when their insertion fails. When INSERT OR REPLACE 1279** encounters a constraint violation, it does not fail. The 1280** INSERT continues to completion after deleting rows that caused 1281** the constraint problem so INSERT OR REPLACE will always change 1282** the return value of this interface. 1283** 1284** For the purposes of this routine, an [INSERT] is considered to 1285** be successful even if it is subsequently rolled back. 1286** 1287** Requirements: 1288** [H12221] [H12223] 1289** 1290** If a separate thread performs a new [INSERT] on the same 1291** database connection while the [sqlite3_last_insert_rowid()] 1292** function is running and thus changes the last insert [rowid], 1293** then the value returned by [sqlite3_last_insert_rowid()] is 1294** unpredictable and might not equal either the old or the new 1295** last insert [rowid]. 1296*/ 1297sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1298 1299/* 1300** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> 1301** 1302** This function returns the number of database rows that were changed 1303** or inserted or deleted by the most recently completed SQL statement 1304** on the [database connection] specified by the first parameter. 1305** Only changes that are directly specified by the [INSERT], [UPDATE], 1306** or [DELETE] statement are counted. Auxiliary changes caused by 1307** triggers are not counted. Use the [sqlite3_total_changes()] function 1308** to find the total number of changes including changes caused by triggers. 1309** 1310** Changes to a view that are simulated by an [INSTEAD OF trigger] 1311** are not counted. Only real table changes are counted. 1312** 1313** A "row change" is a change to a single row of a single table 1314** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1315** are changed as side effects of [REPLACE] constraint resolution, 1316** rollback, ABORT processing, [DROP TABLE], or by any other 1317** mechanisms do not count as direct row changes. 1318** 1319** A "trigger context" is a scope of execution that begins and 1320** ends with the script of a [CREATE TRIGGER | trigger]. 1321** Most SQL statements are 1322** evaluated outside of any trigger. This is the "top level" 1323** trigger context. If a trigger fires from the top level, a 1324** new trigger context is entered for the duration of that one 1325** trigger. Subtriggers create subcontexts for their duration. 1326** 1327** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1328** not create a new trigger context. 1329** 1330** This function returns the number of direct row changes in the 1331** most recent INSERT, UPDATE, or DELETE statement within the same 1332** trigger context. 1333** 1334** Thus, when called from the top level, this function returns the 1335** number of changes in the most recent INSERT, UPDATE, or DELETE 1336** that also occurred at the top level. Within the body of a trigger, 1337** the sqlite3_changes() interface can be called to find the number of 1338** changes in the most recently completed INSERT, UPDATE, or DELETE 1339** statement within the body of the same trigger. 1340** However, the number returned does not include changes 1341** caused by subtriggers since those have their own context. 1342** 1343** See also the [sqlite3_total_changes()] interface and the 1344** [count_changes pragma]. 1345** 1346** Requirements: 1347** [H12241] [H12243] 1348** 1349** If a separate thread makes changes on the same database connection 1350** while [sqlite3_changes()] is running then the value returned 1351** is unpredictable and not meaningful. 1352*/ 1353int sqlite3_changes(sqlite3*); 1354 1355/* 1356** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> 1357** 1358** This function returns the number of row changes caused by [INSERT], 1359** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1360** The count includes all changes from all 1361** [CREATE TRIGGER | trigger] contexts. However, 1362** the count does not include changes used to implement [REPLACE] constraints, 1363** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1364** count does not include rows of views that fire an [INSTEAD OF trigger], 1365** though if the INSTEAD OF trigger makes changes of its own, those changes 1366** are counted. 1367** The changes are counted as soon as the statement that makes them is 1368** completed (when the statement handle is passed to [sqlite3_reset()] or 1369** [sqlite3_finalize()]). 1370** 1371** See also the [sqlite3_changes()] interface and the 1372** [count_changes pragma]. 1373** 1374** Requirements: 1375** [H12261] [H12263] 1376** 1377** If a separate thread makes changes on the same database connection 1378** while [sqlite3_total_changes()] is running then the value 1379** returned is unpredictable and not meaningful. 1380*/ 1381int sqlite3_total_changes(sqlite3*); 1382 1383/* 1384** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> 1385** 1386** This function causes any pending database operation to abort and 1387** return at its earliest opportunity. This routine is typically 1388** called in response to a user action such as pressing "Cancel" 1389** or Ctrl-C where the user wants a long query operation to halt 1390** immediately. 1391** 1392** It is safe to call this routine from a thread different from the 1393** thread that is currently running the database operation. But it 1394** is not safe to call this routine with a [database connection] that 1395** is closed or might close before sqlite3_interrupt() returns. 1396** 1397** If an SQL operation is very nearly finished at the time when 1398** sqlite3_interrupt() is called, then it might not have an opportunity 1399** to be interrupted and might continue to completion. 1400** 1401** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1402** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1403** that is inside an explicit transaction, then the entire transaction 1404** will be rolled back automatically. 1405** 1406** The sqlite3_interrupt(D) call is in effect until all currently running 1407** SQL statements on [database connection] D complete. Any new SQL statements 1408** that are started after the sqlite3_interrupt() call and before the 1409** running statements reaches zero are interrupted as if they had been 1410** running prior to the sqlite3_interrupt() call. New SQL statements 1411** that are started after the running statement count reaches zero are 1412** not effected by the sqlite3_interrupt(). 1413** A call to sqlite3_interrupt(D) that occurs when there are no running 1414** SQL statements is a no-op and has no effect on SQL statements 1415** that are started after the sqlite3_interrupt() call returns. 1416** 1417** Requirements: 1418** [H12271] [H12272] 1419** 1420** If the database connection closes while [sqlite3_interrupt()] 1421** is running then bad things will likely happen. 1422*/ 1423void sqlite3_interrupt(sqlite3*); 1424 1425/* 1426** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> 1427** 1428** These routines are useful during command-line input to determine if the 1429** currently entered text seems to form a complete SQL statement or 1430** if additional input is needed before sending the text into 1431** SQLite for parsing. These routines return 1 if the input string 1432** appears to be a complete SQL statement. A statement is judged to be 1433** complete if it ends with a semicolon token and is not a prefix of a 1434** well-formed CREATE TRIGGER statement. Semicolons that are embedded within 1435** string literals or quoted identifier names or comments are not 1436** independent tokens (they are part of the token in which they are 1437** embedded) and thus do not count as a statement terminator. Whitespace 1438** and comments that follow the final semicolon are ignored. 1439** 1440** These routines return 0 if the statement is incomplete. If a 1441** memory allocation fails, then SQLITE_NOMEM is returned. 1442** 1443** These routines do not parse the SQL statements thus 1444** will not detect syntactically incorrect SQL. 1445** 1446** If SQLite has not been initialized using [sqlite3_initialize()] prior 1447** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1448** automatically by sqlite3_complete16(). If that initialization fails, 1449** then the return value from sqlite3_complete16() will be non-zero 1450** regardless of whether or not the input SQL is complete. 1451** 1452** Requirements: [H10511] [H10512] 1453** 1454** The input to [sqlite3_complete()] must be a zero-terminated 1455** UTF-8 string. 1456** 1457** The input to [sqlite3_complete16()] must be a zero-terminated 1458** UTF-16 string in native byte order. 1459*/ 1460int sqlite3_complete(const char *sql); 1461int sqlite3_complete16(const void *sql); 1462 1463/* 1464** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> 1465** 1466** This routine sets a callback function that might be invoked whenever 1467** an attempt is made to open a database table that another thread 1468** or process has locked. 1469** 1470** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1471** is returned immediately upon encountering the lock. If the busy callback 1472** is not NULL, then the callback will be invoked with two arguments. 1473** 1474** The first argument to the handler is a copy of the void* pointer which 1475** is the third argument to sqlite3_busy_handler(). The second argument to 1476** the handler callback is the number of times that the busy handler has 1477** been invoked for this locking event. If the 1478** busy callback returns 0, then no additional attempts are made to 1479** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1480** If the callback returns non-zero, then another attempt 1481** is made to open the database for reading and the cycle repeats. 1482** 1483** The presence of a busy handler does not guarantee that it will be invoked 1484** when there is lock contention. If SQLite determines that invoking the busy 1485** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1486** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1487** Consider a scenario where one process is holding a read lock that 1488** it is trying to promote to a reserved lock and 1489** a second process is holding a reserved lock that it is trying 1490** to promote to an exclusive lock. The first process cannot proceed 1491** because it is blocked by the second and the second process cannot 1492** proceed because it is blocked by the first. If both processes 1493** invoke the busy handlers, neither will make any progress. Therefore, 1494** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1495** will induce the first process to release its read lock and allow 1496** the second process to proceed. 1497** 1498** The default busy callback is NULL. 1499** 1500** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1501** when SQLite is in the middle of a large transaction where all the 1502** changes will not fit into the in-memory cache. SQLite will 1503** already hold a RESERVED lock on the database file, but it needs 1504** to promote this lock to EXCLUSIVE so that it can spill cache 1505** pages into the database file without harm to concurrent 1506** readers. If it is unable to promote the lock, then the in-memory 1507** cache will be left in an inconsistent state and so the error 1508** code is promoted from the relatively benign [SQLITE_BUSY] to 1509** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1510** forces an automatic rollback of the changes. See the 1511** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1512** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1513** this is important. 1514** 1515** There can only be a single busy handler defined for each 1516** [database connection]. Setting a new busy handler clears any 1517** previously set handler. Note that calling [sqlite3_busy_timeout()] 1518** will also set or clear the busy handler. 1519** 1520** The busy callback should not take any actions which modify the 1521** database connection that invoked the busy handler. Any such actions 1522** result in undefined behavior. 1523** 1524** Requirements: 1525** [H12311] [H12312] [H12314] [H12316] [H12318] 1526** 1527** A busy handler must not close the database connection 1528** or [prepared statement] that invoked the busy handler. 1529*/ 1530int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1531 1532/* 1533** CAPI3REF: Set A Busy Timeout {H12340} <S40410> 1534** 1535** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1536** for a specified amount of time when a table is locked. The handler 1537** will sleep multiple times until at least "ms" milliseconds of sleeping 1538** have accumulated. {H12343} After "ms" milliseconds of sleeping, 1539** the handler returns 0 which causes [sqlite3_step()] to return 1540** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1541** 1542** Calling this routine with an argument less than or equal to zero 1543** turns off all busy handlers. 1544** 1545** There can only be a single busy handler for a particular 1546** [database connection] any any given moment. If another busy handler 1547** was defined (using [sqlite3_busy_handler()]) prior to calling 1548** this routine, that other busy handler is cleared. 1549** 1550** Requirements: 1551** [H12341] [H12343] [H12344] 1552*/ 1553int sqlite3_busy_timeout(sqlite3*, int ms); 1554 1555/* 1556** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> 1557** 1558** Definition: A <b>result table</b> is memory data structure created by the 1559** [sqlite3_get_table()] interface. A result table records the 1560** complete query results from one or more queries. 1561** 1562** The table conceptually has a number of rows and columns. But 1563** these numbers are not part of the result table itself. These 1564** numbers are obtained separately. Let N be the number of rows 1565** and M be the number of columns. 1566** 1567** A result table is an array of pointers to zero-terminated UTF-8 strings. 1568** There are (N+1)*M elements in the array. The first M pointers point 1569** to zero-terminated strings that contain the names of the columns. 1570** The remaining entries all point to query results. NULL values result 1571** in NULL pointers. All other values are in their UTF-8 zero-terminated 1572** string representation as returned by [sqlite3_column_text()]. 1573** 1574** A result table might consist of one or more memory allocations. 1575** It is not safe to pass a result table directly to [sqlite3_free()]. 1576** A result table should be deallocated using [sqlite3_free_table()]. 1577** 1578** As an example of the result table format, suppose a query result 1579** is as follows: 1580** 1581** <blockquote><pre> 1582** Name | Age 1583** ----------------------- 1584** Alice | 43 1585** Bob | 28 1586** Cindy | 21 1587** </pre></blockquote> 1588** 1589** There are two column (M==2) and three rows (N==3). Thus the 1590** result table has 8 entries. Suppose the result table is stored 1591** in an array names azResult. Then azResult holds this content: 1592** 1593** <blockquote><pre> 1594** azResult[0] = "Name"; 1595** azResult[1] = "Age"; 1596** azResult[2] = "Alice"; 1597** azResult[3] = "43"; 1598** azResult[4] = "Bob"; 1599** azResult[5] = "28"; 1600** azResult[6] = "Cindy"; 1601** azResult[7] = "21"; 1602** </pre></blockquote> 1603** 1604** The sqlite3_get_table() function evaluates one or more 1605** semicolon-separated SQL statements in the zero-terminated UTF-8 1606** string of its 2nd parameter. It returns a result table to the 1607** pointer given in its 3rd parameter. 1608** 1609** After the calling function has finished using the result, it should 1610** pass the pointer to the result table to sqlite3_free_table() in order to 1611** release the memory that was malloced. Because of the way the 1612** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1613** function must not try to call [sqlite3_free()] directly. Only 1614** [sqlite3_free_table()] is able to release the memory properly and safely. 1615** 1616** The sqlite3_get_table() interface is implemented as a wrapper around 1617** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1618** to any internal data structures of SQLite. It uses only the public 1619** interface defined here. As a consequence, errors that occur in the 1620** wrapper layer outside of the internal [sqlite3_exec()] call are not 1621** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. 1622** 1623** Requirements: 1624** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] 1625*/ 1626int sqlite3_get_table( 1627 sqlite3 *db, /* An open database */ 1628 const char *zSql, /* SQL to be evaluated */ 1629 char ***pazResult, /* Results of the query */ 1630 int *pnRow, /* Number of result rows written here */ 1631 int *pnColumn, /* Number of result columns written here */ 1632 char **pzErrmsg /* Error msg written here */ 1633); 1634void sqlite3_free_table(char **result); 1635 1636/* 1637** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> 1638** 1639** These routines are work-alikes of the "printf()" family of functions 1640** from the standard C library. 1641** 1642** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1643** results into memory obtained from [sqlite3_malloc()]. 1644** The strings returned by these two routines should be 1645** released by [sqlite3_free()]. Both routines return a 1646** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1647** memory to hold the resulting string. 1648** 1649** In sqlite3_snprintf() routine is similar to "snprintf()" from 1650** the standard C library. The result is written into the 1651** buffer supplied as the second parameter whose size is given by 1652** the first parameter. Note that the order of the 1653** first two parameters is reversed from snprintf(). This is an 1654** historical accident that cannot be fixed without breaking 1655** backwards compatibility. Note also that sqlite3_snprintf() 1656** returns a pointer to its buffer instead of the number of 1657** characters actually written into the buffer. We admit that 1658** the number of characters written would be a more useful return 1659** value but we cannot change the implementation of sqlite3_snprintf() 1660** now without breaking compatibility. 1661** 1662** As long as the buffer size is greater than zero, sqlite3_snprintf() 1663** guarantees that the buffer is always zero-terminated. The first 1664** parameter "n" is the total size of the buffer, including space for 1665** the zero terminator. So the longest string that can be completely 1666** written will be n-1 characters. 1667** 1668** These routines all implement some additional formatting 1669** options that are useful for constructing SQL statements. 1670** All of the usual printf() formatting options apply. In addition, there 1671** is are "%q", "%Q", and "%z" options. 1672** 1673** The %q option works like %s in that it substitutes a null-terminated 1674** string from the argument list. But %q also doubles every '\'' character. 1675** %q is designed for use inside a string literal. By doubling each '\'' 1676** character it escapes that character and allows it to be inserted into 1677** the string. 1678** 1679** For example, assume the string variable zText contains text as follows: 1680** 1681** <blockquote><pre> 1682** char *zText = "It's a happy day!"; 1683** </pre></blockquote> 1684** 1685** One can use this text in an SQL statement as follows: 1686** 1687** <blockquote><pre> 1688** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1689** sqlite3_exec(db, zSQL, 0, 0, 0); 1690** sqlite3_free(zSQL); 1691** </pre></blockquote> 1692** 1693** Because the %q format string is used, the '\'' character in zText 1694** is escaped and the SQL generated is as follows: 1695** 1696** <blockquote><pre> 1697** INSERT INTO table1 VALUES('It''s a happy day!') 1698** </pre></blockquote> 1699** 1700** This is correct. Had we used %s instead of %q, the generated SQL 1701** would have looked like this: 1702** 1703** <blockquote><pre> 1704** INSERT INTO table1 VALUES('It's a happy day!'); 1705** </pre></blockquote> 1706** 1707** This second example is an SQL syntax error. As a general rule you should 1708** always use %q instead of %s when inserting text into a string literal. 1709** 1710** The %Q option works like %q except it also adds single quotes around 1711** the outside of the total string. Additionally, if the parameter in the 1712** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1713** single quotes) in place of the %Q option. So, for example, one could say: 1714** 1715** <blockquote><pre> 1716** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1717** sqlite3_exec(db, zSQL, 0, 0, 0); 1718** sqlite3_free(zSQL); 1719** </pre></blockquote> 1720** 1721** The code above will render a correct SQL statement in the zSQL 1722** variable even if the zText variable is a NULL pointer. 1723** 1724** The "%z" formatting option works exactly like "%s" with the 1725** addition that after the string has been read and copied into 1726** the result, [sqlite3_free()] is called on the input string. {END} 1727** 1728** Requirements: 1729** [H17403] [H17406] [H17407] 1730*/ 1731char *sqlite3_mprintf(const char*,...); 1732char *sqlite3_vmprintf(const char*, va_list); 1733char *sqlite3_snprintf(int,char*,const char*, ...); 1734 1735/* 1736** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> 1737** 1738** The SQLite core uses these three routines for all of its own 1739** internal memory allocation needs. "Core" in the previous sentence 1740** does not include operating-system specific VFS implementation. The 1741** Windows VFS uses native malloc() and free() for some operations. 1742** 1743** The sqlite3_malloc() routine returns a pointer to a block 1744** of memory at least N bytes in length, where N is the parameter. 1745** If sqlite3_malloc() is unable to obtain sufficient free 1746** memory, it returns a NULL pointer. If the parameter N to 1747** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1748** a NULL pointer. 1749** 1750** Calling sqlite3_free() with a pointer previously returned 1751** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1752** that it might be reused. The sqlite3_free() routine is 1753** a no-op if is called with a NULL pointer. Passing a NULL pointer 1754** to sqlite3_free() is harmless. After being freed, memory 1755** should neither be read nor written. Even reading previously freed 1756** memory might result in a segmentation fault or other severe error. 1757** Memory corruption, a segmentation fault, or other severe error 1758** might result if sqlite3_free() is called with a non-NULL pointer that 1759** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 1760** 1761** The sqlite3_realloc() interface attempts to resize a 1762** prior memory allocation to be at least N bytes, where N is the 1763** second parameter. The memory allocation to be resized is the first 1764** parameter. If the first parameter to sqlite3_realloc() 1765** is a NULL pointer then its behavior is identical to calling 1766** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1767** If the second parameter to sqlite3_realloc() is zero or 1768** negative then the behavior is exactly the same as calling 1769** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1770** sqlite3_realloc() returns a pointer to a memory allocation 1771** of at least N bytes in size or NULL if sufficient memory is unavailable. 1772** If M is the size of the prior allocation, then min(N,M) bytes 1773** of the prior allocation are copied into the beginning of buffer returned 1774** by sqlite3_realloc() and the prior allocation is freed. 1775** If sqlite3_realloc() returns NULL, then the prior allocation 1776** is not freed. 1777** 1778** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1779** is always aligned to at least an 8 byte boundary. {END} 1780** 1781** The default implementation of the memory allocation subsystem uses 1782** the malloc(), realloc() and free() provided by the standard C library. 1783** {H17382} However, if SQLite is compiled with the 1784** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> 1785** is an integer), then SQLite create a static array of at least 1786** <i>NNN</i> bytes in size and uses that array for all of its dynamic 1787** memory allocation needs. {END} Additional memory allocator options 1788** may be added in future releases. 1789** 1790** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1791** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1792** implementation of these routines to be omitted. That capability 1793** is no longer provided. Only built-in memory allocators can be used. 1794** 1795** The Windows OS interface layer calls 1796** the system malloc() and free() directly when converting 1797** filenames between the UTF-8 encoding used by SQLite 1798** and whatever filename encoding is used by the particular Windows 1799** installation. Memory allocation errors are detected, but 1800** they are reported back as [SQLITE_CANTOPEN] or 1801** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1802** 1803** Requirements: 1804** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] 1805** [H17321] [H17322] [H17323] 1806** 1807** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1808** must be either NULL or else pointers obtained from a prior 1809** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 1810** not yet been released. 1811** 1812** The application must not read or write any part of 1813** a block of memory after it has been released using 1814** [sqlite3_free()] or [sqlite3_realloc()]. 1815*/ 1816void *sqlite3_malloc(int); 1817void *sqlite3_realloc(void*, int); 1818void sqlite3_free(void*); 1819 1820/* 1821** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> 1822** 1823** SQLite provides these two interfaces for reporting on the status 1824** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1825** routines, which form the built-in memory allocation subsystem. 1826** 1827** Requirements: 1828** [H17371] [H17373] [H17374] [H17375] 1829*/ 1830sqlite3_int64 sqlite3_memory_used(void); 1831sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1832 1833/* 1834** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> 1835** 1836** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1837** select random [ROWID | ROWIDs] when inserting new records into a table that 1838** already uses the largest possible [ROWID]. The PRNG is also used for 1839** the build-in random() and randomblob() SQL functions. This interface allows 1840** applications to access the same PRNG for other purposes. 1841** 1842** A call to this routine stores N bytes of randomness into buffer P. 1843** 1844** The first time this routine is invoked (either internally or by 1845** the application) the PRNG is seeded using randomness obtained 1846** from the xRandomness method of the default [sqlite3_vfs] object. 1847** On all subsequent invocations, the pseudo-randomness is generated 1848** internally and without recourse to the [sqlite3_vfs] xRandomness 1849** method. 1850** 1851** Requirements: 1852** [H17392] 1853*/ 1854void sqlite3_randomness(int N, void *P); 1855 1856/* 1857** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> 1858** 1859** This routine registers a authorizer callback with a particular 1860** [database connection], supplied in the first argument. 1861** The authorizer callback is invoked as SQL statements are being compiled 1862** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1863** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1864** points during the compilation process, as logic is being created 1865** to perform various actions, the authorizer callback is invoked to 1866** see if those actions are allowed. The authorizer callback should 1867** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1868** specific action but allow the SQL statement to continue to be 1869** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1870** rejected with an error. If the authorizer callback returns 1871** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1872** then the [sqlite3_prepare_v2()] or equivalent call that triggered 1873** the authorizer will fail with an error message. 1874** 1875** When the callback returns [SQLITE_OK], that means the operation 1876** requested is ok. When the callback returns [SQLITE_DENY], the 1877** [sqlite3_prepare_v2()] or equivalent call that triggered the 1878** authorizer will fail with an error message explaining that 1879** access is denied. 1880** 1881** The first parameter to the authorizer callback is a copy of the third 1882** parameter to the sqlite3_set_authorizer() interface. The second parameter 1883** to the callback is an integer [SQLITE_COPY | action code] that specifies 1884** the particular action to be authorized. The third through sixth parameters 1885** to the callback are zero-terminated strings that contain additional 1886** details about the action to be authorized. 1887** 1888** If the action code is [SQLITE_READ] 1889** and the callback returns [SQLITE_IGNORE] then the 1890** [prepared statement] statement is constructed to substitute 1891** a NULL value in place of the table column that would have 1892** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1893** return can be used to deny an untrusted user access to individual 1894** columns of a table. 1895** If the action code is [SQLITE_DELETE] and the callback returns 1896** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 1897** [truncate optimization] is disabled and all rows are deleted individually. 1898** 1899** An authorizer is used when [sqlite3_prepare | preparing] 1900** SQL statements from an untrusted source, to ensure that the SQL statements 1901** do not try to access data they are not allowed to see, or that they do not 1902** try to execute malicious statements that damage the database. For 1903** example, an application may allow a user to enter arbitrary 1904** SQL queries for evaluation by a database. But the application does 1905** not want the user to be able to make arbitrary changes to the 1906** database. An authorizer could then be put in place while the 1907** user-entered SQL is being [sqlite3_prepare | prepared] that 1908** disallows everything except [SELECT] statements. 1909** 1910** Applications that need to process SQL from untrusted sources 1911** might also consider lowering resource limits using [sqlite3_limit()] 1912** and limiting database size using the [max_page_count] [PRAGMA] 1913** in addition to using an authorizer. 1914** 1915** Only a single authorizer can be in place on a database connection 1916** at a time. Each call to sqlite3_set_authorizer overrides the 1917** previous call. Disable the authorizer by installing a NULL callback. 1918** The authorizer is disabled by default. 1919** 1920** The authorizer callback must not do anything that will modify 1921** the database connection that invoked the authorizer callback. 1922** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1923** database connections for the meaning of "modify" in this paragraph. 1924** 1925** When [sqlite3_prepare_v2()] is used to prepare a statement, the 1926** statement might be re-prepared during [sqlite3_step()] due to a 1927** schema change. Hence, the application should ensure that the 1928** correct authorizer callback remains in place during the [sqlite3_step()]. 1929** 1930** Note that the authorizer callback is invoked only during 1931** [sqlite3_prepare()] or its variants. Authorization is not 1932** performed during statement evaluation in [sqlite3_step()], unless 1933** as stated in the previous paragraph, sqlite3_step() invokes 1934** sqlite3_prepare_v2() to reprepare a statement after a schema change. 1935** 1936** Requirements: 1937** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] 1938** [H12511] [H12512] [H12520] [H12521] [H12522] 1939*/ 1940int sqlite3_set_authorizer( 1941 sqlite3*, 1942 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1943 void *pUserData 1944); 1945 1946/* 1947** CAPI3REF: Authorizer Return Codes {H12590} <H12500> 1948** 1949** The [sqlite3_set_authorizer | authorizer callback function] must 1950** return either [SQLITE_OK] or one of these two constants in order 1951** to signal SQLite whether or not the action is permitted. See the 1952** [sqlite3_set_authorizer | authorizer documentation] for additional 1953** information. 1954*/ 1955#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1956#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1957 1958/* 1959** CAPI3REF: Authorizer Action Codes {H12550} <H12500> 1960** 1961** The [sqlite3_set_authorizer()] interface registers a callback function 1962** that is invoked to authorize certain SQL statement actions. The 1963** second parameter to the callback is an integer code that specifies 1964** what action is being authorized. These are the integer action codes that 1965** the authorizer callback may be passed. 1966** 1967** These action code values signify what kind of operation is to be 1968** authorized. The 3rd and 4th parameters to the authorization 1969** callback function will be parameters or NULL depending on which of these 1970** codes is used as the second parameter. The 5th parameter to the 1971** authorizer callback is the name of the database ("main", "temp", 1972** etc.) if applicable. The 6th parameter to the authorizer callback 1973** is the name of the inner-most trigger or view that is responsible for 1974** the access attempt or NULL if this access attempt is directly from 1975** top-level SQL code. 1976** 1977** Requirements: 1978** [H12551] [H12552] [H12553] [H12554] 1979*/ 1980/******************************************* 3rd ************ 4th ***********/ 1981#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1982#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1983#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1984#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1985#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1986#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1987#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1988#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1989#define SQLITE_DELETE 9 /* Table Name NULL */ 1990#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1991#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1992#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1993#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1994#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1995#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1996#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1997#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1998#define SQLITE_INSERT 18 /* Table Name NULL */ 1999#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2000#define SQLITE_READ 20 /* Table Name Column Name */ 2001#define SQLITE_SELECT 21 /* NULL NULL */ 2002#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2003#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2004#define SQLITE_ATTACH 24 /* Filename NULL */ 2005#define SQLITE_DETACH 25 /* Database Name NULL */ 2006#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2007#define SQLITE_REINDEX 27 /* Index Name NULL */ 2008#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2009#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2010#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2011#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2012#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2013#define SQLITE_COPY 0 /* No longer used */ 2014 2015/* 2016** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> 2017** EXPERIMENTAL 2018** 2019** These routines register callback functions that can be used for 2020** tracing and profiling the execution of SQL statements. 2021** 2022** The callback function registered by sqlite3_trace() is invoked at 2023** various times when an SQL statement is being run by [sqlite3_step()]. 2024** The callback returns a UTF-8 rendering of the SQL statement text 2025** as the statement first begins executing. Additional callbacks occur 2026** as each triggered subprogram is entered. The callbacks for triggers 2027** contain a UTF-8 SQL comment that identifies the trigger. 2028** 2029** The callback function registered by sqlite3_profile() is invoked 2030** as each SQL statement finishes. The profile callback contains 2031** the original statement text and an estimate of wall-clock time 2032** of how long that statement took to run. 2033** 2034** Requirements: 2035** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] 2036** [H12290] 2037*/ 2038SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2039SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2040 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2041 2042/* 2043** CAPI3REF: Query Progress Callbacks {H12910} <S60400> 2044** 2045** This routine configures a callback function - the 2046** progress callback - that is invoked periodically during long 2047** running calls to [sqlite3_exec()], [sqlite3_step()] and 2048** [sqlite3_get_table()]. An example use for this 2049** interface is to keep a GUI updated during a large query. 2050** 2051** If the progress callback returns non-zero, the operation is 2052** interrupted. This feature can be used to implement a 2053** "Cancel" button on a GUI progress dialog box. 2054** 2055** The progress handler must not do anything that will modify 2056** the database connection that invoked the progress handler. 2057** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2058** database connections for the meaning of "modify" in this paragraph. 2059** 2060** Requirements: 2061** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] 2062** 2063*/ 2064void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2065 2066/* 2067** CAPI3REF: Opening A New Database Connection {H12700} <S40200> 2068** 2069** These routines open an SQLite database file whose name is given by the 2070** filename argument. The filename argument is interpreted as UTF-8 for 2071** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2072** order for sqlite3_open16(). A [database connection] handle is usually 2073** returned in *ppDb, even if an error occurs. The only exception is that 2074** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2075** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2076** object. If the database is opened (and/or created) successfully, then 2077** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The 2078** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2079** an English language description of the error. 2080** 2081** The default encoding for the database will be UTF-8 if 2082** sqlite3_open() or sqlite3_open_v2() is called and 2083** UTF-16 in the native byte order if sqlite3_open16() is used. 2084** 2085** Whether or not an error occurs when it is opened, resources 2086** associated with the [database connection] handle should be released by 2087** passing it to [sqlite3_close()] when it is no longer required. 2088** 2089** The sqlite3_open_v2() interface works like sqlite3_open() 2090** except that it accepts two additional parameters for additional control 2091** over the new database connection. The flags parameter can take one of 2092** the following three values, optionally combined with the 2093** [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags: 2094** 2095** <dl> 2096** <dt>[SQLITE_OPEN_READONLY]</dt> 2097** <dd>The database is opened in read-only mode. If the database does not 2098** already exist, an error is returned.</dd> 2099** 2100** <dt>[SQLITE_OPEN_READWRITE]</dt> 2101** <dd>The database is opened for reading and writing if possible, or reading 2102** only if the file is write protected by the operating system. In either 2103** case the database must already exist, otherwise an error is returned.</dd> 2104** 2105** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2106** <dd>The database is opened for reading and writing, and is creates it if 2107** it does not already exist. This is the behavior that is always used for 2108** sqlite3_open() and sqlite3_open16().</dd> 2109** </dl> 2110** 2111** If the 3rd parameter to sqlite3_open_v2() is not one of the 2112** combinations shown above or one of the combinations shown above combined 2113** with the [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags, 2114** then the behavior is undefined. 2115** 2116** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2117** opens in the multi-thread [threading mode] as long as the single-thread 2118** mode has not been set at compile-time or start-time. If the 2119** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2120** in the serialized [threading mode] unless single-thread was 2121** previously selected at compile-time or start-time. 2122** 2123** If the filename is ":memory:", then a private, temporary in-memory database 2124** is created for the connection. This in-memory database will vanish when 2125** the database connection is closed. Future versions of SQLite might 2126** make use of additional special filenames that begin with the ":" character. 2127** It is recommended that when a database filename actually does begin with 2128** a ":" character you should prefix the filename with a pathname such as 2129** "./" to avoid ambiguity. 2130** 2131** If the filename is an empty string, then a private, temporary 2132** on-disk database will be created. This private database will be 2133** automatically deleted as soon as the database connection is closed. 2134** 2135** The fourth parameter to sqlite3_open_v2() is the name of the 2136** [sqlite3_vfs] object that defines the operating system interface that 2137** the new database connection should use. If the fourth parameter is 2138** a NULL pointer then the default [sqlite3_vfs] object is used. 2139** 2140** <b>Note to Windows users:</b> The encoding used for the filename argument 2141** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2142** codepage is currently defined. Filenames containing international 2143** characters must be converted to UTF-8 prior to passing them into 2144** sqlite3_open() or sqlite3_open_v2(). 2145** 2146** Requirements: 2147** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] 2148** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] 2149*/ 2150int sqlite3_open( 2151 const char *filename, /* Database filename (UTF-8) */ 2152 sqlite3 **ppDb /* OUT: SQLite db handle */ 2153); 2154int sqlite3_open16( 2155 const void *filename, /* Database filename (UTF-16) */ 2156 sqlite3 **ppDb /* OUT: SQLite db handle */ 2157); 2158int sqlite3_open_v2( 2159 const char *filename, /* Database filename (UTF-8) */ 2160 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2161 int flags, /* Flags */ 2162 const char *zVfs /* Name of VFS module to use */ 2163); 2164 2165/* 2166** CAPI3REF: Error Codes And Messages {H12800} <S60200> 2167** 2168** The sqlite3_errcode() interface returns the numeric [result code] or 2169** [extended result code] for the most recent failed sqlite3_* API call 2170** associated with a [database connection]. If a prior API call failed 2171** but the most recent API call succeeded, the return value from 2172** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() 2173** interface is the same except that it always returns the 2174** [extended result code] even when extended result codes are 2175** disabled. 2176** 2177** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2178** text that describes the error, as either UTF-8 or UTF-16 respectively. 2179** Memory to hold the error message string is managed internally. 2180** The application does not need to worry about freeing the result. 2181** However, the error string might be overwritten or deallocated by 2182** subsequent calls to other SQLite interface functions. 2183** 2184** When the serialized [threading mode] is in use, it might be the 2185** case that a second error occurs on a separate thread in between 2186** the time of the first error and the call to these interfaces. 2187** When that happens, the second error will be reported since these 2188** interfaces always report the most recent result. To avoid 2189** this, each thread can obtain exclusive use of the [database connection] D 2190** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2191** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2192** all calls to the interfaces listed here are completed. 2193** 2194** If an interface fails with SQLITE_MISUSE, that means the interface 2195** was invoked incorrectly by the application. In that case, the 2196** error code and message may or may not be set. 2197** 2198** Requirements: 2199** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] 2200*/ 2201int sqlite3_errcode(sqlite3 *db); 2202int sqlite3_extended_errcode(sqlite3 *db); 2203const char *sqlite3_errmsg(sqlite3*); 2204const void *sqlite3_errmsg16(sqlite3*); 2205 2206/* 2207** CAPI3REF: SQL Statement Object {H13000} <H13010> 2208** KEYWORDS: {prepared statement} {prepared statements} 2209** 2210** An instance of this object represents a single SQL statement. 2211** This object is variously known as a "prepared statement" or a 2212** "compiled SQL statement" or simply as a "statement". 2213** 2214** The life of a statement object goes something like this: 2215** 2216** <ol> 2217** <li> Create the object using [sqlite3_prepare_v2()] or a related 2218** function. 2219** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2220** interfaces. 2221** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2222** <li> Reset the statement using [sqlite3_reset()] then go back 2223** to step 2. Do this zero or more times. 2224** <li> Destroy the object using [sqlite3_finalize()]. 2225** </ol> 2226** 2227** Refer to documentation on individual methods above for additional 2228** information. 2229*/ 2230typedef struct sqlite3_stmt sqlite3_stmt; 2231 2232/* 2233** CAPI3REF: Run-time Limits {H12760} <S20600> 2234** 2235** This interface allows the size of various constructs to be limited 2236** on a connection by connection basis. The first parameter is the 2237** [database connection] whose limit is to be set or queried. The 2238** second parameter is one of the [limit categories] that define a 2239** class of constructs to be size limited. The third parameter is the 2240** new limit for that construct. The function returns the old limit. 2241** 2242** If the new limit is a negative number, the limit is unchanged. 2243** For the limit category of SQLITE_LIMIT_XYZ there is a 2244** [limits | hard upper bound] 2245** set by a compile-time C preprocessor macro named 2246** [limits | SQLITE_MAX_XYZ]. 2247** (The "_LIMIT_" in the name is changed to "_MAX_".) 2248** Attempts to increase a limit above its hard upper bound are 2249** silently truncated to the hard upper limit. 2250** 2251** Run time limits are intended for use in applications that manage 2252** both their own internal database and also databases that are controlled 2253** by untrusted external sources. An example application might be a 2254** web browser that has its own databases for storing history and 2255** separate databases controlled by JavaScript applications downloaded 2256** off the Internet. The internal databases can be given the 2257** large, default limits. Databases managed by external sources can 2258** be given much smaller limits designed to prevent a denial of service 2259** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2260** interface to further control untrusted SQL. The size of the database 2261** created by an untrusted script can be contained using the 2262** [max_page_count] [PRAGMA]. 2263** 2264** New run-time limit categories may be added in future releases. 2265** 2266** Requirements: 2267** [H12762] [H12766] [H12769] 2268*/ 2269int sqlite3_limit(sqlite3*, int id, int newVal); 2270 2271/* 2272** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> 2273** KEYWORDS: {limit category} {limit categories} 2274** 2275** These constants define various performance limits 2276** that can be lowered at run-time using [sqlite3_limit()]. 2277** The synopsis of the meanings of the various limits is shown below. 2278** Additional information is available at [limits | Limits in SQLite]. 2279** 2280** <dl> 2281** <dt>SQLITE_LIMIT_LENGTH</dt> 2282** <dd>The maximum size of any string or BLOB or table row.<dd> 2283** 2284** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2285** <dd>The maximum length of an SQL statement.</dd> 2286** 2287** <dt>SQLITE_LIMIT_COLUMN</dt> 2288** <dd>The maximum number of columns in a table definition or in the 2289** result set of a [SELECT] or the maximum number of columns in an index 2290** or in an ORDER BY or GROUP BY clause.</dd> 2291** 2292** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2293** <dd>The maximum depth of the parse tree on any expression.</dd> 2294** 2295** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2296** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2297** 2298** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2299** <dd>The maximum number of instructions in a virtual machine program 2300** used to implement an SQL statement.</dd> 2301** 2302** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2303** <dd>The maximum number of arguments on a function.</dd> 2304** 2305** <dt>SQLITE_LIMIT_ATTACHED</dt> 2306** <dd>The maximum number of [ATTACH | attached databases].</dd> 2307** 2308** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2309** <dd>The maximum length of the pattern argument to the [LIKE] or 2310** [GLOB] operators.</dd> 2311** 2312** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2313** <dd>The maximum number of variables in an SQL statement that can 2314** be bound.</dd> 2315** </dl> 2316*/ 2317#define SQLITE_LIMIT_LENGTH 0 2318#define SQLITE_LIMIT_SQL_LENGTH 1 2319#define SQLITE_LIMIT_COLUMN 2 2320#define SQLITE_LIMIT_EXPR_DEPTH 3 2321#define SQLITE_LIMIT_COMPOUND_SELECT 4 2322#define SQLITE_LIMIT_VDBE_OP 5 2323#define SQLITE_LIMIT_FUNCTION_ARG 6 2324#define SQLITE_LIMIT_ATTACHED 7 2325#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2326#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2327 2328/* 2329** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> 2330** KEYWORDS: {SQL statement compiler} 2331** 2332** To execute an SQL query, it must first be compiled into a byte-code 2333** program using one of these routines. 2334** 2335** The first argument, "db", is a [database connection] obtained from a 2336** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2337** [sqlite3_open16()]. The database connection must not have been closed. 2338** 2339** The second argument, "zSql", is the statement to be compiled, encoded 2340** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2341** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2342** use UTF-16. 2343** 2344** If the nByte argument is less than zero, then zSql is read up to the 2345** first zero terminator. If nByte is non-negative, then it is the maximum 2346** number of bytes read from zSql. When nByte is non-negative, the 2347** zSql string ends at either the first '\000' or '\u0000' character or 2348** the nByte-th byte, whichever comes first. If the caller knows 2349** that the supplied string is nul-terminated, then there is a small 2350** performance advantage to be gained by passing an nByte parameter that 2351** is equal to the number of bytes in the input string <i>including</i> 2352** the nul-terminator bytes. 2353** 2354** If pzTail is not NULL then *pzTail is made to point to the first byte 2355** past the end of the first SQL statement in zSql. These routines only 2356** compile the first statement in zSql, so *pzTail is left pointing to 2357** what remains uncompiled. 2358** 2359** *ppStmt is left pointing to a compiled [prepared statement] that can be 2360** executed using [sqlite3_step()]. If there is an error, *ppStmt is set 2361** to NULL. If the input text contains no SQL (if the input is an empty 2362** string or a comment) then *ppStmt is set to NULL. 2363** The calling procedure is responsible for deleting the compiled 2364** SQL statement using [sqlite3_finalize()] after it has finished with it. 2365** ppStmt may not be NULL. 2366** 2367** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. 2368** 2369** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2370** recommended for all new programs. The two older interfaces are retained 2371** for backwards compatibility, but their use is discouraged. 2372** In the "v2" interfaces, the prepared statement 2373** that is returned (the [sqlite3_stmt] object) contains a copy of the 2374** original SQL text. This causes the [sqlite3_step()] interface to 2375** behave a differently in two ways: 2376** 2377** <ol> 2378** <li> 2379** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2380** always used to do, [sqlite3_step()] will automatically recompile the SQL 2381** statement and try to run it again. If the schema has changed in 2382** a way that makes the statement no longer valid, [sqlite3_step()] will still 2383** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is 2384** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the 2385** error go away. Note: use [sqlite3_errmsg()] to find the text 2386** of the parsing error that results in an [SQLITE_SCHEMA] return. 2387** </li> 2388** 2389** <li> 2390** When an error occurs, [sqlite3_step()] will return one of the detailed 2391** [error codes] or [extended error codes]. The legacy behavior was that 2392** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2393** and you would have to make a second call to [sqlite3_reset()] in order 2394** to find the underlying cause of the problem. With the "v2" prepare 2395** interfaces, the underlying reason for the error is returned immediately. 2396** </li> 2397** </ol> 2398** 2399** Requirements: 2400** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] 2401** 2402*/ 2403int sqlite3_prepare( 2404 sqlite3 *db, /* Database handle */ 2405 const char *zSql, /* SQL statement, UTF-8 encoded */ 2406 int nByte, /* Maximum length of zSql in bytes. */ 2407 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2408 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2409); 2410int sqlite3_prepare_v2( 2411 sqlite3 *db, /* Database handle */ 2412 const char *zSql, /* SQL statement, UTF-8 encoded */ 2413 int nByte, /* Maximum length of zSql in bytes. */ 2414 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2415 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2416); 2417int sqlite3_prepare16( 2418 sqlite3 *db, /* Database handle */ 2419 const void *zSql, /* SQL statement, UTF-16 encoded */ 2420 int nByte, /* Maximum length of zSql in bytes. */ 2421 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2422 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2423); 2424int sqlite3_prepare16_v2( 2425 sqlite3 *db, /* Database handle */ 2426 const void *zSql, /* SQL statement, UTF-16 encoded */ 2427 int nByte, /* Maximum length of zSql in bytes. */ 2428 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2429 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2430); 2431 2432/* 2433** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> 2434** 2435** This interface can be used to retrieve a saved copy of the original 2436** SQL text used to create a [prepared statement] if that statement was 2437** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2438** 2439** Requirements: 2440** [H13101] [H13102] [H13103] 2441*/ 2442const char *sqlite3_sql(sqlite3_stmt *pStmt); 2443 2444/* 2445** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> 2446** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2447** 2448** SQLite uses the sqlite3_value object to represent all values 2449** that can be stored in a database table. SQLite uses dynamic typing 2450** for the values it stores. Values stored in sqlite3_value objects 2451** can be integers, floating point values, strings, BLOBs, or NULL. 2452** 2453** An sqlite3_value object may be either "protected" or "unprotected". 2454** Some interfaces require a protected sqlite3_value. Other interfaces 2455** will accept either a protected or an unprotected sqlite3_value. 2456** Every interface that accepts sqlite3_value arguments specifies 2457** whether or not it requires a protected sqlite3_value. 2458** 2459** The terms "protected" and "unprotected" refer to whether or not 2460** a mutex is held. A internal mutex is held for a protected 2461** sqlite3_value object but no mutex is held for an unprotected 2462** sqlite3_value object. If SQLite is compiled to be single-threaded 2463** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2464** or if SQLite is run in one of reduced mutex modes 2465** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2466** then there is no distinction between protected and unprotected 2467** sqlite3_value objects and they can be used interchangeably. However, 2468** for maximum code portability it is recommended that applications 2469** still make the distinction between between protected and unprotected 2470** sqlite3_value objects even when not strictly required. 2471** 2472** The sqlite3_value objects that are passed as parameters into the 2473** implementation of [application-defined SQL functions] are protected. 2474** The sqlite3_value object returned by 2475** [sqlite3_column_value()] is unprotected. 2476** Unprotected sqlite3_value objects may only be used with 2477** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2478** The [sqlite3_value_blob | sqlite3_value_type()] family of 2479** interfaces require protected sqlite3_value objects. 2480*/ 2481typedef struct Mem sqlite3_value; 2482 2483/* 2484** CAPI3REF: SQL Function Context Object {H16001} <S20200> 2485** 2486** The context in which an SQL function executes is stored in an 2487** sqlite3_context object. A pointer to an sqlite3_context object 2488** is always first parameter to [application-defined SQL functions]. 2489** The application-defined SQL function implementation will pass this 2490** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2491** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2492** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2493** and/or [sqlite3_set_auxdata()]. 2494*/ 2495typedef struct sqlite3_context sqlite3_context; 2496 2497/* 2498** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> 2499** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2500** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2501** 2502** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, 2503** literals may be replaced by a [parameter] that matches one of following 2504** templates: 2505** 2506** <ul> 2507** <li> ? 2508** <li> ?NNN 2509** <li> :VVV 2510** <li> @VVV 2511** <li> $VVV 2512** </ul> 2513** 2514** In the templates above, NNN represents an integer literal, 2515** and VVV represents an alphanumeric identifer. The values of these 2516** parameters (also called "host parameter names" or "SQL parameters") 2517** can be set using the sqlite3_bind_*() routines defined here. 2518** 2519** The first argument to the sqlite3_bind_*() routines is always 2520** a pointer to the [sqlite3_stmt] object returned from 2521** [sqlite3_prepare_v2()] or its variants. 2522** 2523** The second argument is the index of the SQL parameter to be set. 2524** The leftmost SQL parameter has an index of 1. When the same named 2525** SQL parameter is used more than once, second and subsequent 2526** occurrences have the same index as the first occurrence. 2527** The index for named parameters can be looked up using the 2528** [sqlite3_bind_parameter_index()] API if desired. The index 2529** for "?NNN" parameters is the value of NNN. 2530** The NNN value must be between 1 and the [sqlite3_limit()] 2531** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2532** 2533** The third argument is the value to bind to the parameter. 2534** 2535** In those routines that have a fourth argument, its value is the 2536** number of bytes in the parameter. To be clear: the value is the 2537** number of <u>bytes</u> in the value, not the number of characters. 2538** If the fourth parameter is negative, the length of the string is 2539** the number of bytes up to the first zero terminator. 2540** 2541** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2542** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2543** string after SQLite has finished with it. If the fifth argument is 2544** the special value [SQLITE_STATIC], then SQLite assumes that the 2545** information is in static, unmanaged space and does not need to be freed. 2546** If the fifth argument has the value [SQLITE_TRANSIENT], then 2547** SQLite makes its own private copy of the data immediately, before 2548** the sqlite3_bind_*() routine returns. 2549** 2550** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2551** is filled with zeroes. A zeroblob uses a fixed amount of memory 2552** (just an integer to hold its size) while it is being processed. 2553** Zeroblobs are intended to serve as placeholders for BLOBs whose 2554** content is later written using 2555** [sqlite3_blob_open | incremental BLOB I/O] routines. 2556** A negative value for the zeroblob results in a zero-length BLOB. 2557** 2558** The sqlite3_bind_*() routines must be called after 2559** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2560** before [sqlite3_step()]. 2561** Bindings are not cleared by the [sqlite3_reset()] routine. 2562** Unbound parameters are interpreted as NULL. 2563** 2564** These routines return [SQLITE_OK] on success or an error code if 2565** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2566** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. 2567** [SQLITE_MISUSE] might be returned if these routines are called on a 2568** virtual machine that is the wrong state or which has already been finalized. 2569** Detection of misuse is unreliable. Applications should not depend 2570** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2571** a logic error in the application. Future versions of SQLite might 2572** panic rather than return SQLITE_MISUSE. 2573** 2574** See also: [sqlite3_bind_parameter_count()], 2575** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2576** 2577** Requirements: 2578** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] 2579** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] 2580** 2581*/ 2582int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2583int sqlite3_bind_double(sqlite3_stmt*, int, double); 2584int sqlite3_bind_int(sqlite3_stmt*, int, int); 2585int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2586int sqlite3_bind_null(sqlite3_stmt*, int); 2587int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2588int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2589int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2590int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2591 2592/* 2593** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> 2594** 2595** This routine can be used to find the number of [SQL parameters] 2596** in a [prepared statement]. SQL parameters are tokens of the 2597** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2598** placeholders for values that are [sqlite3_bind_blob | bound] 2599** to the parameters at a later time. 2600** 2601** This routine actually returns the index of the largest (rightmost) 2602** parameter. For all forms except ?NNN, this will correspond to the 2603** number of unique parameters. If parameters of the ?NNN are used, 2604** there may be gaps in the list. 2605** 2606** See also: [sqlite3_bind_blob|sqlite3_bind()], 2607** [sqlite3_bind_parameter_name()], and 2608** [sqlite3_bind_parameter_index()]. 2609** 2610** Requirements: 2611** [H13601] 2612*/ 2613int sqlite3_bind_parameter_count(sqlite3_stmt*); 2614 2615/* 2616** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> 2617** 2618** This routine returns a pointer to the name of the n-th 2619** [SQL parameter] in a [prepared statement]. 2620** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2621** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2622** respectively. 2623** In other words, the initial ":" or "$" or "@" or "?" 2624** is included as part of the name. 2625** Parameters of the form "?" without a following integer have no name 2626** and are also referred to as "anonymous parameters". 2627** 2628** The first host parameter has an index of 1, not 0. 2629** 2630** If the value n is out of range or if the n-th parameter is 2631** nameless, then NULL is returned. The returned string is 2632** always in UTF-8 encoding even if the named parameter was 2633** originally specified as UTF-16 in [sqlite3_prepare16()] or 2634** [sqlite3_prepare16_v2()]. 2635** 2636** See also: [sqlite3_bind_blob|sqlite3_bind()], 2637** [sqlite3_bind_parameter_count()], and 2638** [sqlite3_bind_parameter_index()]. 2639** 2640** Requirements: 2641** [H13621] 2642*/ 2643const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2644 2645/* 2646** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> 2647** 2648** Return the index of an SQL parameter given its name. The 2649** index value returned is suitable for use as the second 2650** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2651** is returned if no matching parameter is found. The parameter 2652** name must be given in UTF-8 even if the original statement 2653** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2654** 2655** See also: [sqlite3_bind_blob|sqlite3_bind()], 2656** [sqlite3_bind_parameter_count()], and 2657** [sqlite3_bind_parameter_index()]. 2658** 2659** Requirements: 2660** [H13641] 2661*/ 2662int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2663 2664/* 2665** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> 2666** 2667** Contrary to the intuition of many, [sqlite3_reset()] does not reset 2668** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2669** Use this routine to reset all host parameters to NULL. 2670** 2671** Requirements: 2672** [H13661] 2673*/ 2674int sqlite3_clear_bindings(sqlite3_stmt*); 2675 2676/* 2677** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> 2678** 2679** Return the number of columns in the result set returned by the 2680** [prepared statement]. This routine returns 0 if pStmt is an SQL 2681** statement that does not return data (for example an [UPDATE]). 2682** 2683** Requirements: 2684** [H13711] 2685*/ 2686int sqlite3_column_count(sqlite3_stmt *pStmt); 2687 2688/* 2689** CAPI3REF: Column Names In A Result Set {H13720} <S10700> 2690** 2691** These routines return the name assigned to a particular column 2692** in the result set of a [SELECT] statement. The sqlite3_column_name() 2693** interface returns a pointer to a zero-terminated UTF-8 string 2694** and sqlite3_column_name16() returns a pointer to a zero-terminated 2695** UTF-16 string. The first parameter is the [prepared statement] 2696** that implements the [SELECT] statement. The second parameter is the 2697** column number. The leftmost column is number 0. 2698** 2699** The returned string pointer is valid until either the [prepared statement] 2700** is destroyed by [sqlite3_finalize()] or until the next call to 2701** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2702** 2703** If sqlite3_malloc() fails during the processing of either routine 2704** (for example during a conversion from UTF-8 to UTF-16) then a 2705** NULL pointer is returned. 2706** 2707** The name of a result column is the value of the "AS" clause for 2708** that column, if there is an AS clause. If there is no AS clause 2709** then the name of the column is unspecified and may change from 2710** one release of SQLite to the next. 2711** 2712** Requirements: 2713** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] 2714*/ 2715const char *sqlite3_column_name(sqlite3_stmt*, int N); 2716const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2717 2718/* 2719** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> 2720** 2721** These routines provide a means to determine what column of what 2722** table in which database a result of a [SELECT] statement comes from. 2723** The name of the database or table or column can be returned as 2724** either a UTF-8 or UTF-16 string. The _database_ routines return 2725** the database name, the _table_ routines return the table name, and 2726** the origin_ routines return the column name. 2727** The returned string is valid until the [prepared statement] is destroyed 2728** using [sqlite3_finalize()] or until the same information is requested 2729** again in a different encoding. 2730** 2731** The names returned are the original un-aliased names of the 2732** database, table, and column. 2733** 2734** The first argument to the following calls is a [prepared statement]. 2735** These functions return information about the Nth column returned by 2736** the statement, where N is the second function argument. 2737** 2738** If the Nth column returned by the statement is an expression or 2739** subquery and is not a column value, then all of these functions return 2740** NULL. These routine might also return NULL if a memory allocation error 2741** occurs. Otherwise, they return the name of the attached database, table 2742** and column that query result column was extracted from. 2743** 2744** As with all other SQLite APIs, those postfixed with "16" return 2745** UTF-16 encoded strings, the other functions return UTF-8. {END} 2746** 2747** These APIs are only available if the library was compiled with the 2748** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 2749** 2750** {A13751} 2751** If two or more threads call one or more of these routines against the same 2752** prepared statement and column at the same time then the results are 2753** undefined. 2754** 2755** Requirements: 2756** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] 2757** 2758** If two or more threads call one or more 2759** [sqlite3_column_database_name | column metadata interfaces] 2760** for the same [prepared statement] and result column 2761** at the same time then the results are undefined. 2762*/ 2763const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2764const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2765const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2766const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2767const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2768const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2769 2770/* 2771** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> 2772** 2773** The first parameter is a [prepared statement]. 2774** If this statement is a [SELECT] statement and the Nth column of the 2775** returned result set of that [SELECT] is a table column (not an 2776** expression or subquery) then the declared type of the table 2777** column is returned. If the Nth column of the result set is an 2778** expression or subquery, then a NULL pointer is returned. 2779** The returned string is always UTF-8 encoded. {END} 2780** 2781** For example, given the database schema: 2782** 2783** CREATE TABLE t1(c1 VARIANT); 2784** 2785** and the following statement to be compiled: 2786** 2787** SELECT c1 + 1, c1 FROM t1; 2788** 2789** this routine would return the string "VARIANT" for the second result 2790** column (i==1), and a NULL pointer for the first result column (i==0). 2791** 2792** SQLite uses dynamic run-time typing. So just because a column 2793** is declared to contain a particular type does not mean that the 2794** data stored in that column is of the declared type. SQLite is 2795** strongly typed, but the typing is dynamic not static. Type 2796** is associated with individual values, not with the containers 2797** used to hold those values. 2798** 2799** Requirements: 2800** [H13761] [H13762] [H13763] 2801*/ 2802const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2803const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2804 2805/* 2806** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> 2807** 2808** After a [prepared statement] has been prepared using either 2809** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 2810** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 2811** must be called one or more times to evaluate the statement. 2812** 2813** The details of the behavior of the sqlite3_step() interface depend 2814** on whether the statement was prepared using the newer "v2" interface 2815** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 2816** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 2817** new "v2" interface is recommended for new applications but the legacy 2818** interface will continue to be supported. 2819** 2820** In the legacy interface, the return value will be either [SQLITE_BUSY], 2821** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 2822** With the "v2" interface, any of the other [result codes] or 2823** [extended result codes] might be returned as well. 2824** 2825** [SQLITE_BUSY] means that the database engine was unable to acquire the 2826** database locks it needs to do its job. If the statement is a [COMMIT] 2827** or occurs outside of an explicit transaction, then you can retry the 2828** statement. If the statement is not a [COMMIT] and occurs within a 2829** explicit transaction then you should rollback the transaction before 2830** continuing. 2831** 2832** [SQLITE_DONE] means that the statement has finished executing 2833** successfully. sqlite3_step() should not be called again on this virtual 2834** machine without first calling [sqlite3_reset()] to reset the virtual 2835** machine back to its initial state. 2836** 2837** If the SQL statement being executed returns any data, then [SQLITE_ROW] 2838** is returned each time a new row of data is ready for processing by the 2839** caller. The values may be accessed using the [column access functions]. 2840** sqlite3_step() is called again to retrieve the next row of data. 2841** 2842** [SQLITE_ERROR] means that a run-time error (such as a constraint 2843** violation) has occurred. sqlite3_step() should not be called again on 2844** the VM. More information may be found by calling [sqlite3_errmsg()]. 2845** With the legacy interface, a more specific error code (for example, 2846** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 2847** can be obtained by calling [sqlite3_reset()] on the 2848** [prepared statement]. In the "v2" interface, 2849** the more specific error code is returned directly by sqlite3_step(). 2850** 2851** [SQLITE_MISUSE] means that the this routine was called inappropriately. 2852** Perhaps it was called on a [prepared statement] that has 2853** already been [sqlite3_finalize | finalized] or on one that had 2854** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 2855** be the case that the same database connection is being used by two or 2856** more threads at the same moment in time. 2857** 2858** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 2859** API always returns a generic error code, [SQLITE_ERROR], following any 2860** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 2861** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 2862** specific [error codes] that better describes the error. 2863** We admit that this is a goofy design. The problem has been fixed 2864** with the "v2" interface. If you prepare all of your SQL statements 2865** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 2866** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 2867** then the more specific [error codes] are returned directly 2868** by sqlite3_step(). The use of the "v2" interface is recommended. 2869** 2870** Requirements: 2871** [H13202] [H15304] [H15306] [H15308] [H15310] 2872*/ 2873int sqlite3_step(sqlite3_stmt*); 2874 2875/* 2876** CAPI3REF: Number of columns in a result set {H13770} <S10700> 2877** 2878** Returns the number of values in the current row of the result set. 2879** 2880** Requirements: 2881** [H13771] [H13772] 2882*/ 2883int sqlite3_data_count(sqlite3_stmt *pStmt); 2884 2885/* 2886** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> 2887** KEYWORDS: SQLITE_TEXT 2888** 2889** {H10266} Every value in SQLite has one of five fundamental datatypes: 2890** 2891** <ul> 2892** <li> 64-bit signed integer 2893** <li> 64-bit IEEE floating point number 2894** <li> string 2895** <li> BLOB 2896** <li> NULL 2897** </ul> {END} 2898** 2899** These constants are codes for each of those types. 2900** 2901** Note that the SQLITE_TEXT constant was also used in SQLite version 2 2902** for a completely different meaning. Software that links against both 2903** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 2904** SQLITE_TEXT. 2905*/ 2906#define SQLITE_INTEGER 1 2907#define SQLITE_FLOAT 2 2908#define SQLITE_BLOB 4 2909#define SQLITE_NULL 5 2910#ifdef SQLITE_TEXT 2911# undef SQLITE_TEXT 2912#else 2913# define SQLITE_TEXT 3 2914#endif 2915#define SQLITE3_TEXT 3 2916 2917/* 2918** CAPI3REF: Result Values From A Query {H13800} <S10700> 2919** KEYWORDS: {column access functions} 2920** 2921** These routines form the "result set query" interface. 2922** 2923** These routines return information about a single column of the current 2924** result row of a query. In every case the first argument is a pointer 2925** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 2926** that was returned from [sqlite3_prepare_v2()] or one of its variants) 2927** and the second argument is the index of the column for which information 2928** should be returned. The leftmost column of the result set has the index 0. 2929** 2930** If the SQL statement does not currently point to a valid row, or if the 2931** column index is out of range, the result is undefined. 2932** These routines may only be called when the most recent call to 2933** [sqlite3_step()] has returned [SQLITE_ROW] and neither 2934** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 2935** If any of these routines are called after [sqlite3_reset()] or 2936** [sqlite3_finalize()] or after [sqlite3_step()] has returned 2937** something other than [SQLITE_ROW], the results are undefined. 2938** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 2939** are called from a different thread while any of these routines 2940** are pending, then the results are undefined. 2941** 2942** The sqlite3_column_type() routine returns the 2943** [SQLITE_INTEGER | datatype code] for the initial data type 2944** of the result column. The returned value is one of [SQLITE_INTEGER], 2945** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 2946** returned by sqlite3_column_type() is only meaningful if no type 2947** conversions have occurred as described below. After a type conversion, 2948** the value returned by sqlite3_column_type() is undefined. Future 2949** versions of SQLite may change the behavior of sqlite3_column_type() 2950** following a type conversion. 2951** 2952** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 2953** routine returns the number of bytes in that BLOB or string. 2954** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 2955** the string to UTF-8 and then returns the number of bytes. 2956** If the result is a numeric value then sqlite3_column_bytes() uses 2957** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 2958** the number of bytes in that string. 2959** The value returned does not include the zero terminator at the end 2960** of the string. For clarity: the value returned is the number of 2961** bytes in the string, not the number of characters. 2962** 2963** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 2964** even empty strings, are always zero terminated. The return 2965** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary 2966** pointer, possibly even a NULL pointer. 2967** 2968** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 2969** but leaves the result in UTF-16 in native byte order instead of UTF-8. 2970** The zero terminator is not included in this count. 2971** 2972** The object returned by [sqlite3_column_value()] is an 2973** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 2974** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 2975** If the [unprotected sqlite3_value] object returned by 2976** [sqlite3_column_value()] is used in any other way, including calls 2977** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 2978** or [sqlite3_value_bytes()], then the behavior is undefined. 2979** 2980** These routines attempt to convert the value where appropriate. For 2981** example, if the internal representation is FLOAT and a text result 2982** is requested, [sqlite3_snprintf()] is used internally to perform the 2983** conversion automatically. The following table details the conversions 2984** that are applied: 2985** 2986** <blockquote> 2987** <table border="1"> 2988** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 2989** 2990** <tr><td> NULL <td> INTEGER <td> Result is 0 2991** <tr><td> NULL <td> FLOAT <td> Result is 0.0 2992** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 2993** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 2994** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 2995** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 2996** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 2997** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 2998** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 2999** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3000** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3001** <tr><td> TEXT <td> FLOAT <td> Use atof() 3002** <tr><td> TEXT <td> BLOB <td> No change 3003** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3004** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3005** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3006** </table> 3007** </blockquote> 3008** 3009** The table above makes reference to standard C library functions atoi() 3010** and atof(). SQLite does not really use these functions. It has its 3011** own equivalent internal routines. The atoi() and atof() names are 3012** used in the table for brevity and because they are familiar to most 3013** C programmers. 3014** 3015** Note that when type conversions occur, pointers returned by prior 3016** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3017** sqlite3_column_text16() may be invalidated. 3018** Type conversions and pointer invalidations might occur 3019** in the following cases: 3020** 3021** <ul> 3022** <li> The initial content is a BLOB and sqlite3_column_text() or 3023** sqlite3_column_text16() is called. A zero-terminator might 3024** need to be added to the string.</li> 3025** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3026** sqlite3_column_text16() is called. The content must be converted 3027** to UTF-16.</li> 3028** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3029** sqlite3_column_text() is called. The content must be converted 3030** to UTF-8.</li> 3031** </ul> 3032** 3033** Conversions between UTF-16be and UTF-16le are always done in place and do 3034** not invalidate a prior pointer, though of course the content of the buffer 3035** that the prior pointer points to will have been modified. Other kinds 3036** of conversion are done in place when it is possible, but sometimes they 3037** are not possible and in those cases prior pointers are invalidated. 3038** 3039** The safest and easiest to remember policy is to invoke these routines 3040** in one of the following ways: 3041** 3042** <ul> 3043** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3044** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3045** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3046** </ul> 3047** 3048** In other words, you should call sqlite3_column_text(), 3049** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3050** into the desired format, then invoke sqlite3_column_bytes() or 3051** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3052** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3053** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3054** with calls to sqlite3_column_bytes(). 3055** 3056** The pointers returned are valid until a type conversion occurs as 3057** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3058** [sqlite3_finalize()] is called. The memory space used to hold strings 3059** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3060** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3061** [sqlite3_free()]. 3062** 3063** If a memory allocation error occurs during the evaluation of any 3064** of these routines, a default value is returned. The default value 3065** is either the integer 0, the floating point number 0.0, or a NULL 3066** pointer. Subsequent calls to [sqlite3_errcode()] will return 3067** [SQLITE_NOMEM]. 3068** 3069** Requirements: 3070** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] 3071** [H13827] [H13830] 3072*/ 3073const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3074int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3075int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3076double sqlite3_column_double(sqlite3_stmt*, int iCol); 3077int sqlite3_column_int(sqlite3_stmt*, int iCol); 3078sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3079const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3080const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3081int sqlite3_column_type(sqlite3_stmt*, int iCol); 3082sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3083 3084/* 3085** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> 3086** 3087** The sqlite3_finalize() function is called to delete a [prepared statement]. 3088** If the statement was executed successfully or not executed at all, then 3089** SQLITE_OK is returned. If execution of the statement failed then an 3090** [error code] or [extended error code] is returned. 3091** 3092** This routine can be called at any point during the execution of the 3093** [prepared statement]. If the virtual machine has not 3094** completed execution when this routine is called, that is like 3095** encountering an error or an [sqlite3_interrupt | interrupt]. 3096** Incomplete updates may be rolled back and transactions canceled, 3097** depending on the circumstances, and the 3098** [error code] returned will be [SQLITE_ABORT]. 3099** 3100** Requirements: 3101** [H11302] [H11304] 3102*/ 3103int sqlite3_finalize(sqlite3_stmt *pStmt); 3104 3105/* 3106** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> 3107** 3108** The sqlite3_reset() function is called to reset a [prepared statement] 3109** object back to its initial state, ready to be re-executed. 3110** Any SQL statement variables that had values bound to them using 3111** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3112** Use [sqlite3_clear_bindings()] to reset the bindings. 3113** 3114** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3115** back to the beginning of its program. 3116** 3117** {H11334} If the most recent call to [sqlite3_step(S)] for the 3118** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3119** or if [sqlite3_step(S)] has never before been called on S, 3120** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3121** 3122** {H11336} If the most recent call to [sqlite3_step(S)] for the 3123** [prepared statement] S indicated an error, then 3124** [sqlite3_reset(S)] returns an appropriate [error code]. 3125** 3126** {H11338} The [sqlite3_reset(S)] interface does not change the values 3127** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3128*/ 3129int sqlite3_reset(sqlite3_stmt *pStmt); 3130 3131/* 3132** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> 3133** KEYWORDS: {function creation routines} 3134** KEYWORDS: {application-defined SQL function} 3135** KEYWORDS: {application-defined SQL functions} 3136** 3137** These two functions (collectively known as "function creation routines") 3138** are used to add SQL functions or aggregates or to redefine the behavior 3139** of existing SQL functions or aggregates. The only difference between the 3140** two is that the second parameter, the name of the (scalar) function or 3141** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 3142** for sqlite3_create_function16(). 3143** 3144** The first parameter is the [database connection] to which the SQL 3145** function is to be added. If a single program uses more than one database 3146** connection internally, then SQL functions must be added individually to 3147** each database connection. 3148** 3149** The second parameter is the name of the SQL function to be created or 3150** redefined. The length of the name is limited to 255 bytes, exclusive of 3151** the zero-terminator. Note that the name length limit is in bytes, not 3152** characters. Any attempt to create a function with a longer name 3153** will result in [SQLITE_ERROR] being returned. 3154** 3155** The third parameter (nArg) 3156** is the number of arguments that the SQL function or 3157** aggregate takes. If this parameter is -1, then the SQL function or 3158** aggregate may take any number of arguments between 0 and the limit 3159** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3160** parameter is less than -1 or greater than 127 then the behavior is 3161** undefined. 3162** 3163** The fourth parameter, eTextRep, specifies what 3164** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3165** its parameters. Any SQL function implementation should be able to work 3166** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3167** more efficient with one encoding than another. An application may 3168** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3169** times with the same function but with different values of eTextRep. 3170** When multiple implementations of the same function are available, SQLite 3171** will pick the one that involves the least amount of data conversion. 3172** If there is only a single implementation which does not care what text 3173** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3174** 3175** The fifth parameter is an arbitrary pointer. The implementation of the 3176** function can gain access to this pointer using [sqlite3_user_data()]. 3177** 3178** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3179** pointers to C-language functions that implement the SQL function or 3180** aggregate. A scalar SQL function requires an implementation of the xFunc 3181** callback only, NULL pointers should be passed as the xStep and xFinal 3182** parameters. An aggregate SQL function requires an implementation of xStep 3183** and xFinal and NULL should be passed for xFunc. To delete an existing 3184** SQL function or aggregate, pass NULL for all three function callbacks. 3185** 3186** It is permitted to register multiple implementations of the same 3187** functions with the same name but with either differing numbers of 3188** arguments or differing preferred text encodings. SQLite will use 3189** the implementation that most closely matches the way in which the 3190** SQL function is used. A function implementation with a non-negative 3191** nArg parameter is a better match than a function implementation with 3192** a negative nArg. A function where the preferred text encoding 3193** matches the database encoding is a better 3194** match than a function where the encoding is different. 3195** A function where the encoding difference is between UTF16le and UTF16be 3196** is a closer match than a function where the encoding difference is 3197** between UTF8 and UTF16. 3198** 3199** Built-in functions may be overloaded by new application-defined functions. 3200** The first application-defined function with a given name overrides all 3201** built-in functions in the same [database connection] with the same name. 3202** Subsequent application-defined functions of the same name only override 3203** prior application-defined functions that are an exact match for the 3204** number of parameters and preferred encoding. 3205** 3206** An application-defined function is permitted to call other 3207** SQLite interfaces. However, such calls must not 3208** close the database connection nor finalize or reset the prepared 3209** statement in which the function is running. 3210** 3211** Requirements: 3212** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16127] 3213** [H16130] [H16133] [H16136] [H16139] [H16142] 3214*/ 3215int sqlite3_create_function( 3216 sqlite3 *db, 3217 const char *zFunctionName, 3218 int nArg, 3219 int eTextRep, 3220 void *pApp, 3221 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3222 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3223 void (*xFinal)(sqlite3_context*) 3224); 3225int sqlite3_create_function16( 3226 sqlite3 *db, 3227 const void *zFunctionName, 3228 int nArg, 3229 int eTextRep, 3230 void *pApp, 3231 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3232 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3233 void (*xFinal)(sqlite3_context*) 3234); 3235 3236/* 3237** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> 3238** 3239** These constant define integer codes that represent the various 3240** text encodings supported by SQLite. 3241*/ 3242#define SQLITE_UTF8 1 3243#define SQLITE_UTF16LE 2 3244#define SQLITE_UTF16BE 3 3245#define SQLITE_UTF16 4 /* Use native byte order */ 3246#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3247#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3248 3249/* 3250** CAPI3REF: Deprecated Functions 3251** DEPRECATED 3252** 3253** These functions are [deprecated]. In order to maintain 3254** backwards compatibility with older code, these functions continue 3255** to be supported. However, new applications should avoid 3256** the use of these functions. To help encourage people to avoid 3257** using these functions, we are not going to tell you what they do. 3258*/ 3259#ifndef SQLITE_OMIT_DEPRECATED 3260SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3261SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3262SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3263SQLITE_DEPRECATED int sqlite3_global_recover(void); 3264SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3265SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3266#endif 3267 3268/* 3269** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> 3270** 3271** The C-language implementation of SQL functions and aggregates uses 3272** this set of interface routines to access the parameter values on 3273** the function or aggregate. 3274** 3275** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3276** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3277** define callbacks that implement the SQL functions and aggregates. 3278** The 4th parameter to these callbacks is an array of pointers to 3279** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3280** each parameter to the SQL function. These routines are used to 3281** extract values from the [sqlite3_value] objects. 3282** 3283** These routines work only with [protected sqlite3_value] objects. 3284** Any attempt to use these routines on an [unprotected sqlite3_value] 3285** object results in undefined behavior. 3286** 3287** These routines work just like the corresponding [column access functions] 3288** except that these routines take a single [protected sqlite3_value] object 3289** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3290** 3291** The sqlite3_value_text16() interface extracts a UTF-16 string 3292** in the native byte-order of the host machine. The 3293** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3294** extract UTF-16 strings as big-endian and little-endian respectively. 3295** 3296** The sqlite3_value_numeric_type() interface attempts to apply 3297** numeric affinity to the value. This means that an attempt is 3298** made to convert the value to an integer or floating point. If 3299** such a conversion is possible without loss of information (in other 3300** words, if the value is a string that looks like a number) 3301** then the conversion is performed. Otherwise no conversion occurs. 3302** The [SQLITE_INTEGER | datatype] after conversion is returned. 3303** 3304** Please pay particular attention to the fact that the pointer returned 3305** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3306** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3307** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3308** or [sqlite3_value_text16()]. 3309** 3310** These routines must be called from the same thread as 3311** the SQL function that supplied the [sqlite3_value*] parameters. 3312** 3313** Requirements: 3314** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] 3315** [H15127] [H15130] [H15133] [H15136] 3316*/ 3317const void *sqlite3_value_blob(sqlite3_value*); 3318int sqlite3_value_bytes(sqlite3_value*); 3319int sqlite3_value_bytes16(sqlite3_value*); 3320double sqlite3_value_double(sqlite3_value*); 3321int sqlite3_value_int(sqlite3_value*); 3322sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3323const unsigned char *sqlite3_value_text(sqlite3_value*); 3324const void *sqlite3_value_text16(sqlite3_value*); 3325const void *sqlite3_value_text16le(sqlite3_value*); 3326const void *sqlite3_value_text16be(sqlite3_value*); 3327int sqlite3_value_type(sqlite3_value*); 3328int sqlite3_value_numeric_type(sqlite3_value*); 3329 3330/* 3331** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> 3332** 3333** The implementation of aggregate SQL functions use this routine to allocate 3334** a structure for storing their state. 3335** 3336** The first time the sqlite3_aggregate_context() routine is called for a 3337** particular aggregate, SQLite allocates nBytes of memory, zeroes out that 3338** memory, and returns a pointer to it. On second and subsequent calls to 3339** sqlite3_aggregate_context() for the same aggregate function index, 3340** the same buffer is returned. The implementation of the aggregate can use 3341** the returned buffer to accumulate data. 3342** 3343** SQLite automatically frees the allocated buffer when the aggregate 3344** query concludes. 3345** 3346** The first parameter should be a copy of the 3347** [sqlite3_context | SQL function context] that is the first parameter 3348** to the callback routine that implements the aggregate function. 3349** 3350** This routine must be called from the same thread in which 3351** the aggregate SQL function is running. 3352** 3353** Requirements: 3354** [H16211] [H16213] [H16215] [H16217] 3355*/ 3356void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3357 3358/* 3359** CAPI3REF: User Data For Functions {H16240} <S20200> 3360** 3361** The sqlite3_user_data() interface returns a copy of 3362** the pointer that was the pUserData parameter (the 5th parameter) 3363** of the [sqlite3_create_function()] 3364** and [sqlite3_create_function16()] routines that originally 3365** registered the application defined function. {END} 3366** 3367** This routine must be called from the same thread in which 3368** the application-defined function is running. 3369** 3370** Requirements: 3371** [H16243] 3372*/ 3373void *sqlite3_user_data(sqlite3_context*); 3374 3375/* 3376** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> 3377** 3378** The sqlite3_context_db_handle() interface returns a copy of 3379** the pointer to the [database connection] (the 1st parameter) 3380** of the [sqlite3_create_function()] 3381** and [sqlite3_create_function16()] routines that originally 3382** registered the application defined function. 3383** 3384** Requirements: 3385** [H16253] 3386*/ 3387sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3388 3389/* 3390** CAPI3REF: Function Auxiliary Data {H16270} <S20200> 3391** 3392** The following two functions may be used by scalar SQL functions to 3393** associate metadata with argument values. If the same value is passed to 3394** multiple invocations of the same SQL function during query execution, under 3395** some circumstances the associated metadata may be preserved. This may 3396** be used, for example, to add a regular-expression matching scalar 3397** function. The compiled version of the regular expression is stored as 3398** metadata associated with the SQL value passed as the regular expression 3399** pattern. The compiled regular expression can be reused on multiple 3400** invocations of the same function so that the original pattern string 3401** does not need to be recompiled on each invocation. 3402** 3403** The sqlite3_get_auxdata() interface returns a pointer to the metadata 3404** associated by the sqlite3_set_auxdata() function with the Nth argument 3405** value to the application-defined function. If no metadata has been ever 3406** been set for the Nth argument of the function, or if the corresponding 3407** function parameter has changed since the meta-data was set, 3408** then sqlite3_get_auxdata() returns a NULL pointer. 3409** 3410** The sqlite3_set_auxdata() interface saves the metadata 3411** pointed to by its 3rd parameter as the metadata for the N-th 3412** argument of the application-defined function. Subsequent 3413** calls to sqlite3_get_auxdata() might return this data, if it has 3414** not been destroyed. 3415** If it is not NULL, SQLite will invoke the destructor 3416** function given by the 4th parameter to sqlite3_set_auxdata() on 3417** the metadata when the corresponding function parameter changes 3418** or when the SQL statement completes, whichever comes first. 3419** 3420** SQLite is free to call the destructor and drop metadata on any 3421** parameter of any function at any time. The only guarantee is that 3422** the destructor will be called before the metadata is dropped. 3423** 3424** In practice, metadata is preserved between function calls for 3425** expressions that are constant at compile time. This includes literal 3426** values and SQL variables. 3427** 3428** These routines must be called from the same thread in which 3429** the SQL function is running. 3430** 3431** Requirements: 3432** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] 3433*/ 3434void *sqlite3_get_auxdata(sqlite3_context*, int N); 3435void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3436 3437 3438/* 3439** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> 3440** 3441** These are special values for the destructor that is passed in as the 3442** final argument to routines like [sqlite3_result_blob()]. If the destructor 3443** argument is SQLITE_STATIC, it means that the content pointer is constant 3444** and will never change. It does not need to be destroyed. The 3445** SQLITE_TRANSIENT value means that the content will likely change in 3446** the near future and that SQLite should make its own private copy of 3447** the content before returning. 3448** 3449** The typedef is necessary to work around problems in certain 3450** C++ compilers. See ticket #2191. 3451*/ 3452typedef void (*sqlite3_destructor_type)(void*); 3453#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3454#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3455 3456/* 3457** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> 3458** 3459** These routines are used by the xFunc or xFinal callbacks that 3460** implement SQL functions and aggregates. See 3461** [sqlite3_create_function()] and [sqlite3_create_function16()] 3462** for additional information. 3463** 3464** These functions work very much like the [parameter binding] family of 3465** functions used to bind values to host parameters in prepared statements. 3466** Refer to the [SQL parameter] documentation for additional information. 3467** 3468** The sqlite3_result_blob() interface sets the result from 3469** an application-defined function to be the BLOB whose content is pointed 3470** to by the second parameter and which is N bytes long where N is the 3471** third parameter. 3472** 3473** The sqlite3_result_zeroblob() interfaces set the result of 3474** the application-defined function to be a BLOB containing all zero 3475** bytes and N bytes in size, where N is the value of the 2nd parameter. 3476** 3477** The sqlite3_result_double() interface sets the result from 3478** an application-defined function to be a floating point value specified 3479** by its 2nd argument. 3480** 3481** The sqlite3_result_error() and sqlite3_result_error16() functions 3482** cause the implemented SQL function to throw an exception. 3483** SQLite uses the string pointed to by the 3484** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3485** as the text of an error message. SQLite interprets the error 3486** message string from sqlite3_result_error() as UTF-8. SQLite 3487** interprets the string from sqlite3_result_error16() as UTF-16 in native 3488** byte order. If the third parameter to sqlite3_result_error() 3489** or sqlite3_result_error16() is negative then SQLite takes as the error 3490** message all text up through the first zero character. 3491** If the third parameter to sqlite3_result_error() or 3492** sqlite3_result_error16() is non-negative then SQLite takes that many 3493** bytes (not characters) from the 2nd parameter as the error message. 3494** The sqlite3_result_error() and sqlite3_result_error16() 3495** routines make a private copy of the error message text before 3496** they return. Hence, the calling function can deallocate or 3497** modify the text after they return without harm. 3498** The sqlite3_result_error_code() function changes the error code 3499** returned by SQLite as a result of an error in a function. By default, 3500** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3501** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3502** 3503** The sqlite3_result_toobig() interface causes SQLite to throw an error 3504** indicating that a string or BLOB is to long to represent. 3505** 3506** The sqlite3_result_nomem() interface causes SQLite to throw an error 3507** indicating that a memory allocation failed. 3508** 3509** The sqlite3_result_int() interface sets the return value 3510** of the application-defined function to be the 32-bit signed integer 3511** value given in the 2nd argument. 3512** The sqlite3_result_int64() interface sets the return value 3513** of the application-defined function to be the 64-bit signed integer 3514** value given in the 2nd argument. 3515** 3516** The sqlite3_result_null() interface sets the return value 3517** of the application-defined function to be NULL. 3518** 3519** The sqlite3_result_text(), sqlite3_result_text16(), 3520** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3521** set the return value of the application-defined function to be 3522** a text string which is represented as UTF-8, UTF-16 native byte order, 3523** UTF-16 little endian, or UTF-16 big endian, respectively. 3524** SQLite takes the text result from the application from 3525** the 2nd parameter of the sqlite3_result_text* interfaces. 3526** If the 3rd parameter to the sqlite3_result_text* interfaces 3527** is negative, then SQLite takes result text from the 2nd parameter 3528** through the first zero character. 3529** If the 3rd parameter to the sqlite3_result_text* interfaces 3530** is non-negative, then as many bytes (not characters) of the text 3531** pointed to by the 2nd parameter are taken as the application-defined 3532** function result. 3533** If the 4th parameter to the sqlite3_result_text* interfaces 3534** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3535** function as the destructor on the text or BLOB result when it has 3536** finished using that result. 3537** If the 4th parameter to the sqlite3_result_text* interfaces or to 3538** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3539** assumes that the text or BLOB result is in constant space and does not 3540** copy the content of the parameter nor call a destructor on the content 3541** when it has finished using that result. 3542** If the 4th parameter to the sqlite3_result_text* interfaces 3543** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3544** then SQLite makes a copy of the result into space obtained from 3545** from [sqlite3_malloc()] before it returns. 3546** 3547** The sqlite3_result_value() interface sets the result of 3548** the application-defined function to be a copy the 3549** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3550** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3551** so that the [sqlite3_value] specified in the parameter may change or 3552** be deallocated after sqlite3_result_value() returns without harm. 3553** A [protected sqlite3_value] object may always be used where an 3554** [unprotected sqlite3_value] object is required, so either 3555** kind of [sqlite3_value] object can be used with this interface. 3556** 3557** If these routines are called from within the different thread 3558** than the one containing the application-defined function that received 3559** the [sqlite3_context] pointer, the results are undefined. 3560** 3561** Requirements: 3562** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] 3563** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] 3564** [H16451] [H16454] [H16457] [H16460] [H16463] 3565*/ 3566void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3567void sqlite3_result_double(sqlite3_context*, double); 3568void sqlite3_result_error(sqlite3_context*, const char*, int); 3569void sqlite3_result_error16(sqlite3_context*, const void*, int); 3570void sqlite3_result_error_toobig(sqlite3_context*); 3571void sqlite3_result_error_nomem(sqlite3_context*); 3572void sqlite3_result_error_code(sqlite3_context*, int); 3573void sqlite3_result_int(sqlite3_context*, int); 3574void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3575void sqlite3_result_null(sqlite3_context*); 3576void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3577void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3578void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3579void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3580void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3581void sqlite3_result_zeroblob(sqlite3_context*, int n); 3582 3583/* 3584** CAPI3REF: Define New Collating Sequences {H16600} <S20300> 3585** 3586** These functions are used to add new collation sequences to the 3587** [database connection] specified as the first argument. 3588** 3589** The name of the new collation sequence is specified as a UTF-8 string 3590** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3591** and a UTF-16 string for sqlite3_create_collation16(). In all cases 3592** the name is passed as the second function argument. 3593** 3594** The third argument may be one of the constants [SQLITE_UTF8], 3595** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied 3596** routine expects to be passed pointers to strings encoded using UTF-8, 3597** UTF-16 little-endian, or UTF-16 big-endian, respectively. The 3598** third argument might also be [SQLITE_UTF16] to indicate that the routine 3599** expects pointers to be UTF-16 strings in the native byte order, or the 3600** argument can be [SQLITE_UTF16_ALIGNED] if the 3601** the routine expects pointers to 16-bit word aligned strings 3602** of UTF-16 in the native byte order. 3603** 3604** A pointer to the user supplied routine must be passed as the fifth 3605** argument. If it is NULL, this is the same as deleting the collation 3606** sequence (so that SQLite cannot call it anymore). 3607** Each time the application supplied function is invoked, it is passed 3608** as its first parameter a copy of the void* passed as the fourth argument 3609** to sqlite3_create_collation() or sqlite3_create_collation16(). 3610** 3611** The remaining arguments to the application-supplied routine are two strings, 3612** each represented by a (length, data) pair and encoded in the encoding 3613** that was passed as the third argument when the collation sequence was 3614** registered. {END} The application defined collation routine should 3615** return negative, zero or positive if the first string is less than, 3616** equal to, or greater than the second string. i.e. (STRING1 - STRING2). 3617** 3618** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3619** except that it takes an extra argument which is a destructor for 3620** the collation. The destructor is called when the collation is 3621** destroyed and is passed a copy of the fourth parameter void* pointer 3622** of the sqlite3_create_collation_v2(). 3623** Collations are destroyed when they are overridden by later calls to the 3624** collation creation functions or when the [database connection] is closed 3625** using [sqlite3_close()]. 3626** 3627** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 3628** 3629** Requirements: 3630** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] 3631** [H16624] [H16627] [H16630] 3632*/ 3633int sqlite3_create_collation( 3634 sqlite3*, 3635 const char *zName, 3636 int eTextRep, 3637 void*, 3638 int(*xCompare)(void*,int,const void*,int,const void*) 3639); 3640int sqlite3_create_collation_v2( 3641 sqlite3*, 3642 const char *zName, 3643 int eTextRep, 3644 void*, 3645 int(*xCompare)(void*,int,const void*,int,const void*), 3646 void(*xDestroy)(void*) 3647); 3648int sqlite3_create_collation16( 3649 sqlite3*, 3650 const void *zName, 3651 int eTextRep, 3652 void*, 3653 int(*xCompare)(void*,int,const void*,int,const void*) 3654); 3655 3656/* 3657** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> 3658** 3659** To avoid having to register all collation sequences before a database 3660** can be used, a single callback function may be registered with the 3661** [database connection] to be called whenever an undefined collation 3662** sequence is required. 3663** 3664** If the function is registered using the sqlite3_collation_needed() API, 3665** then it is passed the names of undefined collation sequences as strings 3666** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, 3667** the names are passed as UTF-16 in machine native byte order. 3668** A call to either function replaces any existing callback. 3669** 3670** When the callback is invoked, the first argument passed is a copy 3671** of the second argument to sqlite3_collation_needed() or 3672** sqlite3_collation_needed16(). The second argument is the database 3673** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 3674** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 3675** sequence function required. The fourth parameter is the name of the 3676** required collation sequence. 3677** 3678** The callback function should register the desired collation using 3679** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 3680** [sqlite3_create_collation_v2()]. 3681** 3682** Requirements: 3683** [H16702] [H16704] [H16706] 3684*/ 3685int sqlite3_collation_needed( 3686 sqlite3*, 3687 void*, 3688 void(*)(void*,sqlite3*,int eTextRep,const char*) 3689); 3690int sqlite3_collation_needed16( 3691 sqlite3*, 3692 void*, 3693 void(*)(void*,sqlite3*,int eTextRep,const void*) 3694); 3695 3696/* 3697** Specify the key for an encrypted database. This routine should be 3698** called right after sqlite3_open(). 3699** 3700** The code to implement this API is not available in the public release 3701** of SQLite. 3702*/ 3703int sqlite3_key( 3704 sqlite3 *db, /* Database to be rekeyed */ 3705 const void *pKey, int nKey /* The key */ 3706); 3707 3708/* 3709** Change the key on an open database. If the current database is not 3710** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 3711** database is decrypted. 3712** 3713** The code to implement this API is not available in the public release 3714** of SQLite. 3715*/ 3716int sqlite3_rekey( 3717 sqlite3 *db, /* Database to be rekeyed */ 3718 const void *pKey, int nKey /* The new key */ 3719); 3720 3721/* 3722** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> 3723** 3724** The sqlite3_sleep() function causes the current thread to suspend execution 3725** for at least a number of milliseconds specified in its parameter. 3726** 3727** If the operating system does not support sleep requests with 3728** millisecond time resolution, then the time will be rounded up to 3729** the nearest second. The number of milliseconds of sleep actually 3730** requested from the operating system is returned. 3731** 3732** SQLite implements this interface by calling the xSleep() 3733** method of the default [sqlite3_vfs] object. 3734** 3735** Requirements: [H10533] [H10536] 3736*/ 3737int sqlite3_sleep(int); 3738 3739/* 3740** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> 3741** 3742** If this global variable is made to point to a string which is 3743** the name of a folder (a.k.a. directory), then all temporary files 3744** created by SQLite will be placed in that directory. If this variable 3745** is a NULL pointer, then SQLite performs a search for an appropriate 3746** temporary file directory. 3747** 3748** It is not safe to read or modify this variable in more than one 3749** thread at a time. It is not safe to read or modify this variable 3750** if a [database connection] is being used at the same time in a separate 3751** thread. 3752** It is intended that this variable be set once 3753** as part of process initialization and before any SQLite interface 3754** routines have been called and that this variable remain unchanged 3755** thereafter. 3756** 3757** The [temp_store_directory pragma] may modify this variable and cause 3758** it to point to memory obtained from [sqlite3_malloc]. Furthermore, 3759** the [temp_store_directory pragma] always assumes that any string 3760** that this variable points to is held in memory obtained from 3761** [sqlite3_malloc] and the pragma may attempt to free that memory 3762** using [sqlite3_free]. 3763** Hence, if this variable is modified directly, either it should be 3764** made NULL or made to point to memory obtained from [sqlite3_malloc] 3765** or else the use of the [temp_store_directory pragma] should be avoided. 3766*/ 3767SQLITE_EXTERN char *sqlite3_temp_directory; 3768 3769/* 3770** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> 3771** KEYWORDS: {autocommit mode} 3772** 3773** The sqlite3_get_autocommit() interface returns non-zero or 3774** zero if the given database connection is or is not in autocommit mode, 3775** respectively. Autocommit mode is on by default. 3776** Autocommit mode is disabled by a [BEGIN] statement. 3777** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 3778** 3779** If certain kinds of errors occur on a statement within a multi-statement 3780** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 3781** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 3782** transaction might be rolled back automatically. The only way to 3783** find out whether SQLite automatically rolled back the transaction after 3784** an error is to use this function. 3785** 3786** If another thread changes the autocommit status of the database 3787** connection while this routine is running, then the return value 3788** is undefined. 3789** 3790** Requirements: [H12931] [H12932] [H12933] [H12934] 3791*/ 3792int sqlite3_get_autocommit(sqlite3*); 3793 3794/* 3795** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> 3796** 3797** The sqlite3_db_handle interface returns the [database connection] handle 3798** to which a [prepared statement] belongs. The [database connection] 3799** returned by sqlite3_db_handle is the same [database connection] that was the first argument 3800** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 3801** create the statement in the first place. 3802** 3803** Requirements: [H13123] 3804*/ 3805sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 3806 3807/* 3808** CAPI3REF: Find the next prepared statement {H13140} <S60600> 3809** 3810** This interface returns a pointer to the next [prepared statement] after 3811** pStmt associated with the [database connection] pDb. If pStmt is NULL 3812** then this interface returns a pointer to the first prepared statement 3813** associated with the database connection pDb. If no prepared statement 3814** satisfies the conditions of this routine, it returns NULL. 3815** 3816** The [database connection] pointer D in a call to 3817** [sqlite3_next_stmt(D,S)] must refer to an open database 3818** connection and in particular must not be a NULL pointer. 3819** 3820** Requirements: [H13143] [H13146] [H13149] [H13152] 3821*/ 3822sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 3823 3824/* 3825** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> 3826** 3827** The sqlite3_commit_hook() interface registers a callback 3828** function to be invoked whenever a transaction is [COMMIT | committed]. 3829** Any callback set by a previous call to sqlite3_commit_hook() 3830** for the same database connection is overridden. 3831** The sqlite3_rollback_hook() interface registers a callback 3832** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 3833** Any callback set by a previous call to sqlite3_commit_hook() 3834** for the same database connection is overridden. 3835** The pArg argument is passed through to the callback. 3836** If the callback on a commit hook function returns non-zero, 3837** then the commit is converted into a rollback. 3838** 3839** If another function was previously registered, its 3840** pArg value is returned. Otherwise NULL is returned. 3841** 3842** The callback implementation must not do anything that will modify 3843** the database connection that invoked the callback. Any actions 3844** to modify the database connection must be deferred until after the 3845** completion of the [sqlite3_step()] call that triggered the commit 3846** or rollback hook in the first place. 3847** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3848** database connections for the meaning of "modify" in this paragraph. 3849** 3850** Registering a NULL function disables the callback. 3851** 3852** When the commit hook callback routine returns zero, the [COMMIT] 3853** operation is allowed to continue normally. If the commit hook 3854** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 3855** The rollback hook is invoked on a rollback that results from a commit 3856** hook returning non-zero, just as it would be with any other rollback. 3857** 3858** For the purposes of this API, a transaction is said to have been 3859** rolled back if an explicit "ROLLBACK" statement is executed, or 3860** an error or constraint causes an implicit rollback to occur. 3861** The rollback callback is not invoked if a transaction is 3862** automatically rolled back because the database connection is closed. 3863** The rollback callback is not invoked if a transaction is 3864** rolled back because a commit callback returned non-zero. 3865** <todo> Check on this </todo> 3866** 3867** See also the [sqlite3_update_hook()] interface. 3868** 3869** Requirements: 3870** [H12951] [H12952] [H12953] [H12954] [H12955] 3871** [H12961] [H12962] [H12963] [H12964] 3872*/ 3873void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 3874void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 3875 3876/* 3877** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> 3878** 3879** The sqlite3_update_hook() interface registers a callback function 3880** with the [database connection] identified by the first argument 3881** to be invoked whenever a row is updated, inserted or deleted. 3882** Any callback set by a previous call to this function 3883** for the same database connection is overridden. 3884** 3885** The second argument is a pointer to the function to invoke when a 3886** row is updated, inserted or deleted. 3887** The first argument to the callback is a copy of the third argument 3888** to sqlite3_update_hook(). 3889** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 3890** or [SQLITE_UPDATE], depending on the operation that caused the callback 3891** to be invoked. 3892** The third and fourth arguments to the callback contain pointers to the 3893** database and table name containing the affected row. 3894** The final callback parameter is the [rowid] of the row. 3895** In the case of an update, this is the [rowid] after the update takes place. 3896** 3897** The update hook is not invoked when internal system tables are 3898** modified (i.e. sqlite_master and sqlite_sequence). 3899** 3900** In the current implementation, the update hook 3901** is not invoked when duplication rows are deleted because of an 3902** [ON CONFLICT | ON CONFLICT REPLACE] clause. Nor is the update hook 3903** invoked when rows are deleted using the [truncate optimization]. 3904** The exceptions defined in this paragraph might change in a future 3905** release of SQLite. 3906** 3907** The update hook implementation must not do anything that will modify 3908** the database connection that invoked the update hook. Any actions 3909** to modify the database connection must be deferred until after the 3910** completion of the [sqlite3_step()] call that triggered the update hook. 3911** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3912** database connections for the meaning of "modify" in this paragraph. 3913** 3914** If another function was previously registered, its pArg value 3915** is returned. Otherwise NULL is returned. 3916** 3917** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 3918** interfaces. 3919** 3920** Requirements: 3921** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] 3922*/ 3923void *sqlite3_update_hook( 3924 sqlite3*, 3925 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 3926 void* 3927); 3928 3929/* 3930** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> 3931** KEYWORDS: {shared cache} 3932** 3933** This routine enables or disables the sharing of the database cache 3934** and schema data structures between [database connection | connections] 3935** to the same database. Sharing is enabled if the argument is true 3936** and disabled if the argument is false. 3937** 3938** Cache sharing is enabled and disabled for an entire process. 3939** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 3940** sharing was enabled or disabled for each thread separately. 3941** 3942** The cache sharing mode set by this interface effects all subsequent 3943** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 3944** Existing database connections continue use the sharing mode 3945** that was in effect at the time they were opened. 3946** 3947** Virtual tables cannot be used with a shared cache. When shared 3948** cache is enabled, the [sqlite3_create_module()] API used to register 3949** virtual tables will always return an error. 3950** 3951** This routine returns [SQLITE_OK] if shared cache was enabled or disabled 3952** successfully. An [error code] is returned otherwise. 3953** 3954** Shared cache is disabled by default. But this might change in 3955** future releases of SQLite. Applications that care about shared 3956** cache setting should set it explicitly. 3957** 3958** See Also: [SQLite Shared-Cache Mode] 3959** 3960** Requirements: [H10331] [H10336] [H10337] [H10339] 3961*/ 3962int sqlite3_enable_shared_cache(int); 3963 3964/* 3965** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> 3966** 3967** The sqlite3_release_memory() interface attempts to free N bytes 3968** of heap memory by deallocating non-essential memory allocations 3969** held by the database library. {END} Memory used to cache database 3970** pages to improve performance is an example of non-essential memory. 3971** sqlite3_release_memory() returns the number of bytes actually freed, 3972** which might be more or less than the amount requested. 3973** 3974** Requirements: [H17341] [H17342] 3975*/ 3976int sqlite3_release_memory(int); 3977 3978/* 3979** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> 3980** 3981** The sqlite3_soft_heap_limit() interface places a "soft" limit 3982** on the amount of heap memory that may be allocated by SQLite. 3983** If an internal allocation is requested that would exceed the 3984** soft heap limit, [sqlite3_release_memory()] is invoked one or 3985** more times to free up some space before the allocation is performed. 3986** 3987** The limit is called "soft", because if [sqlite3_release_memory()] 3988** cannot free sufficient memory to prevent the limit from being exceeded, 3989** the memory is allocated anyway and the current operation proceeds. 3990** 3991** A negative or zero value for N means that there is no soft heap limit and 3992** [sqlite3_release_memory()] will only be called when memory is exhausted. 3993** The default value for the soft heap limit is zero. 3994** 3995** SQLite makes a best effort to honor the soft heap limit. 3996** But if the soft heap limit cannot be honored, execution will 3997** continue without error or notification. This is why the limit is 3998** called a "soft" limit. It is advisory only. 3999** 4000** Prior to SQLite version 3.5.0, this routine only constrained the memory 4001** allocated by a single thread - the same thread in which this routine 4002** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 4003** applied to all threads. The value specified for the soft heap limit 4004** is an upper bound on the total memory allocation for all threads. In 4005** version 3.5.0 there is no mechanism for limiting the heap usage for 4006** individual threads. 4007** 4008** Requirements: 4009** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] 4010*/ 4011void sqlite3_soft_heap_limit(int); 4012 4013/* 4014** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> 4015** 4016** This routine returns metadata about a specific column of a specific 4017** database table accessible using the [database connection] handle 4018** passed as the first function argument. 4019** 4020** The column is identified by the second, third and fourth parameters to 4021** this function. The second parameter is either the name of the database 4022** (i.e. "main", "temp" or an attached database) containing the specified 4023** table or NULL. If it is NULL, then all attached databases are searched 4024** for the table using the same algorithm used by the database engine to 4025** resolve unqualified table references. 4026** 4027** The third and fourth parameters to this function are the table and column 4028** name of the desired column, respectively. Neither of these parameters 4029** may be NULL. 4030** 4031** Metadata is returned by writing to the memory locations passed as the 5th 4032** and subsequent parameters to this function. Any of these arguments may be 4033** NULL, in which case the corresponding element of metadata is omitted. 4034** 4035** <blockquote> 4036** <table border="1"> 4037** <tr><th> Parameter <th> Output<br>Type <th> Description 4038** 4039** <tr><td> 5th <td> const char* <td> Data type 4040** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4041** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4042** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4043** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4044** </table> 4045** </blockquote> 4046** 4047** The memory pointed to by the character pointers returned for the 4048** declaration type and collation sequence is valid only until the next 4049** call to any SQLite API function. 4050** 4051** If the specified table is actually a view, an [error code] is returned. 4052** 4053** If the specified column is "rowid", "oid" or "_rowid_" and an 4054** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4055** parameters are set for the explicitly declared column. If there is no 4056** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4057** parameters are set as follows: 4058** 4059** <pre> 4060** data type: "INTEGER" 4061** collation sequence: "BINARY" 4062** not null: 0 4063** primary key: 1 4064** auto increment: 0 4065** </pre> 4066** 4067** This function may load one or more schemas from database files. If an 4068** error occurs during this process, or if the requested table or column 4069** cannot be found, an [error code] is returned and an error message left 4070** in the [database connection] (to be retrieved using sqlite3_errmsg()). 4071** 4072** This API is only available if the library was compiled with the 4073** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4074*/ 4075int sqlite3_table_column_metadata( 4076 sqlite3 *db, /* Connection handle */ 4077 const char *zDbName, /* Database name or NULL */ 4078 const char *zTableName, /* Table name */ 4079 const char *zColumnName, /* Column name */ 4080 char const **pzDataType, /* OUTPUT: Declared data type */ 4081 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4082 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4083 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4084 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4085); 4086 4087/* 4088** CAPI3REF: Load An Extension {H12600} <S20500> 4089** 4090** This interface loads an SQLite extension library from the named file. 4091** 4092** {H12601} The sqlite3_load_extension() interface attempts to load an 4093** SQLite extension library contained in the file zFile. 4094** 4095** {H12602} The entry point is zProc. 4096** 4097** {H12603} zProc may be 0, in which case the name of the entry point 4098** defaults to "sqlite3_extension_init". 4099** 4100** {H12604} The sqlite3_load_extension() interface shall return 4101** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4102** 4103** {H12605} If an error occurs and pzErrMsg is not 0, then the 4104** [sqlite3_load_extension()] interface shall attempt to 4105** fill *pzErrMsg with error message text stored in memory 4106** obtained from [sqlite3_malloc()]. {END} The calling function 4107** should free this memory by calling [sqlite3_free()]. 4108** 4109** {H12606} Extension loading must be enabled using 4110** [sqlite3_enable_load_extension()] prior to calling this API, 4111** otherwise an error will be returned. 4112*/ 4113int sqlite3_load_extension( 4114 sqlite3 *db, /* Load the extension into this database connection */ 4115 const char *zFile, /* Name of the shared library containing extension */ 4116 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4117 char **pzErrMsg /* Put error message here if not 0 */ 4118); 4119 4120/* 4121** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> 4122** 4123** So as not to open security holes in older applications that are 4124** unprepared to deal with extension loading, and as a means of disabling 4125** extension loading while evaluating user-entered SQL, the following API 4126** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4127** 4128** Extension loading is off by default. See ticket #1863. 4129** 4130** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 4131** to turn extension loading on and call it with onoff==0 to turn 4132** it back off again. 4133** 4134** {H12622} Extension loading is off by default. 4135*/ 4136int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4137 4138/* 4139** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> 4140** 4141** This API can be invoked at program startup in order to register 4142** one or more statically linked extensions that will be available 4143** to all new [database connections]. {END} 4144** 4145** This routine stores a pointer to the extension in an array that is 4146** obtained from [sqlite3_malloc()]. If you run a memory leak checker 4147** on your program and it reports a leak because of this array, invoke 4148** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. 4149** 4150** {H12641} This function registers an extension entry point that is 4151** automatically invoked whenever a new [database connection] 4152** is opened using [sqlite3_open()], [sqlite3_open16()], 4153** or [sqlite3_open_v2()]. 4154** 4155** {H12642} Duplicate extensions are detected so calling this routine 4156** multiple times with the same extension is harmless. 4157** 4158** {H12643} This routine stores a pointer to the extension in an array 4159** that is obtained from [sqlite3_malloc()]. 4160** 4161** {H12644} Automatic extensions apply across all threads. 4162*/ 4163int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4164 4165/* 4166** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> 4167** 4168** This function disables all previously registered automatic 4169** extensions. {END} It undoes the effect of all prior 4170** [sqlite3_auto_extension()] calls. 4171** 4172** {H12661} This function disables all previously registered 4173** automatic extensions. 4174** 4175** {H12662} This function disables automatic extensions in all threads. 4176*/ 4177void sqlite3_reset_auto_extension(void); 4178 4179/* 4180****** EXPERIMENTAL - subject to change without notice ************** 4181** 4182** The interface to the virtual-table mechanism is currently considered 4183** to be experimental. The interface might change in incompatible ways. 4184** If this is a problem for you, do not use the interface at this time. 4185** 4186** When the virtual-table mechanism stabilizes, we will declare the 4187** interface fixed, support it indefinitely, and remove this comment. 4188*/ 4189 4190/* 4191** Structures used by the virtual table interface 4192*/ 4193typedef struct sqlite3_vtab sqlite3_vtab; 4194typedef struct sqlite3_index_info sqlite3_index_info; 4195typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4196typedef struct sqlite3_module sqlite3_module; 4197 4198/* 4199** CAPI3REF: Virtual Table Object {H18000} <S20400> 4200** KEYWORDS: sqlite3_module {virtual table module} 4201** EXPERIMENTAL 4202** 4203** This structure, sometimes called a a "virtual table module", 4204** defines the implementation of a [virtual tables]. 4205** This structure consists mostly of methods for the module. 4206** 4207** A virtual table module is created by filling in a persistent 4208** instance of this structure and passing a pointer to that instance 4209** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4210** The registration remains valid until it is replaced by a different 4211** module or until the [database connection] closes. The content 4212** of this structure must not change while it is registered with 4213** any database connection. 4214*/ 4215struct sqlite3_module { 4216 int iVersion; 4217 int (*xCreate)(sqlite3*, void *pAux, 4218 int argc, const char *const*argv, 4219 sqlite3_vtab **ppVTab, char**); 4220 int (*xConnect)(sqlite3*, void *pAux, 4221 int argc, const char *const*argv, 4222 sqlite3_vtab **ppVTab, char**); 4223 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4224 int (*xDisconnect)(sqlite3_vtab *pVTab); 4225 int (*xDestroy)(sqlite3_vtab *pVTab); 4226 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4227 int (*xClose)(sqlite3_vtab_cursor*); 4228 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4229 int argc, sqlite3_value **argv); 4230 int (*xNext)(sqlite3_vtab_cursor*); 4231 int (*xEof)(sqlite3_vtab_cursor*); 4232 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4233 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4234 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4235 int (*xBegin)(sqlite3_vtab *pVTab); 4236 int (*xSync)(sqlite3_vtab *pVTab); 4237 int (*xCommit)(sqlite3_vtab *pVTab); 4238 int (*xRollback)(sqlite3_vtab *pVTab); 4239 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4240 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4241 void **ppArg); 4242 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4243}; 4244 4245/* 4246** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> 4247** KEYWORDS: sqlite3_index_info 4248** EXPERIMENTAL 4249** 4250** The sqlite3_index_info structure and its substructures is used to 4251** pass information into and receive the reply from the [xBestIndex] 4252** method of a [virtual table module]. The fields under **Inputs** are the 4253** inputs to xBestIndex and are read-only. xBestIndex inserts its 4254** results into the **Outputs** fields. 4255** 4256** The aConstraint[] array records WHERE clause constraints of the form: 4257** 4258** <pre>column OP expr</pre> 4259** 4260** where OP is =, <, <=, >, or >=. The particular operator is 4261** stored in aConstraint[].op. The index of the column is stored in 4262** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4263** expr on the right-hand side can be evaluated (and thus the constraint 4264** is usable) and false if it cannot. 4265** 4266** The optimizer automatically inverts terms of the form "expr OP column" 4267** and makes other simplifications to the WHERE clause in an attempt to 4268** get as many WHERE clause terms into the form shown above as possible. 4269** The aConstraint[] array only reports WHERE clause terms in the correct 4270** form that refer to the particular virtual table being queried. 4271** 4272** Information about the ORDER BY clause is stored in aOrderBy[]. 4273** Each term of aOrderBy records a column of the ORDER BY clause. 4274** 4275** The [xBestIndex] method must fill aConstraintUsage[] with information 4276** about what parameters to pass to xFilter. If argvIndex>0 then 4277** the right-hand side of the corresponding aConstraint[] is evaluated 4278** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4279** is true, then the constraint is assumed to be fully handled by the 4280** virtual table and is not checked again by SQLite. 4281** 4282** The idxNum and idxPtr values are recorded and passed into the 4283** [xFilter] method. 4284** [sqlite3_free()] is used to free idxPtr if and only iff 4285** needToFreeIdxPtr is true. 4286** 4287** The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4288** the correct order to satisfy the ORDER BY clause so that no separate 4289** sorting step is required. 4290** 4291** The estimatedCost value is an estimate of the cost of doing the 4292** particular lookup. A full scan of a table with N entries should have 4293** a cost of N. A binary search of a table of N entries should have a 4294** cost of approximately log(N). 4295*/ 4296struct sqlite3_index_info { 4297 /* Inputs */ 4298 int nConstraint; /* Number of entries in aConstraint */ 4299 struct sqlite3_index_constraint { 4300 int iColumn; /* Column on left-hand side of constraint */ 4301 unsigned char op; /* Constraint operator */ 4302 unsigned char usable; /* True if this constraint is usable */ 4303 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4304 } *aConstraint; /* Table of WHERE clause constraints */ 4305 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4306 struct sqlite3_index_orderby { 4307 int iColumn; /* Column number */ 4308 unsigned char desc; /* True for DESC. False for ASC. */ 4309 } *aOrderBy; /* The ORDER BY clause */ 4310 /* Outputs */ 4311 struct sqlite3_index_constraint_usage { 4312 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4313 unsigned char omit; /* Do not code a test for this constraint */ 4314 } *aConstraintUsage; 4315 int idxNum; /* Number used to identify the index */ 4316 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4317 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4318 int orderByConsumed; /* True if output is already ordered */ 4319 double estimatedCost; /* Estimated cost of using this index */ 4320}; 4321#define SQLITE_INDEX_CONSTRAINT_EQ 2 4322#define SQLITE_INDEX_CONSTRAINT_GT 4 4323#define SQLITE_INDEX_CONSTRAINT_LE 8 4324#define SQLITE_INDEX_CONSTRAINT_LT 16 4325#define SQLITE_INDEX_CONSTRAINT_GE 32 4326#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4327 4328/* 4329** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> 4330** EXPERIMENTAL 4331** 4332** This routine is used to register a new [virtual table module] name. 4333** Module names must be registered before 4334** creating a new [virtual table] using the module, or before using a 4335** preexisting [virtual table] for the module. 4336** 4337** The module name is registered on the [database connection] specified 4338** by the first parameter. The name of the module is given by the 4339** second parameter. The third parameter is a pointer to 4340** the implementation of the [virtual table module]. The fourth 4341** parameter is an arbitrary client data pointer that is passed through 4342** into the [xCreate] and [xConnect] methods of the virtual table module 4343** when a new virtual table is be being created or reinitialized. 4344** 4345** This interface has exactly the same effect as calling 4346** [sqlite3_create_module_v2()] with a NULL client data destructor. 4347*/ 4348SQLITE_EXPERIMENTAL int sqlite3_create_module( 4349 sqlite3 *db, /* SQLite connection to register module with */ 4350 const char *zName, /* Name of the module */ 4351 const sqlite3_module *p, /* Methods for the module */ 4352 void *pClientData /* Client data for xCreate/xConnect */ 4353); 4354 4355/* 4356** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> 4357** EXPERIMENTAL 4358** 4359** This routine is identical to the [sqlite3_create_module()] method, 4360** except that it has an extra parameter to specify 4361** a destructor function for the client data pointer. SQLite will 4362** invoke the destructor function (if it is not NULL) when SQLite 4363** no longer needs the pClientData pointer. 4364*/ 4365SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( 4366 sqlite3 *db, /* SQLite connection to register module with */ 4367 const char *zName, /* Name of the module */ 4368 const sqlite3_module *p, /* Methods for the module */ 4369 void *pClientData, /* Client data for xCreate/xConnect */ 4370 void(*xDestroy)(void*) /* Module destructor function */ 4371); 4372 4373/* 4374** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> 4375** KEYWORDS: sqlite3_vtab 4376** EXPERIMENTAL 4377** 4378** Every [virtual table module] implementation uses a subclass 4379** of the following structure to describe a particular instance 4380** of the [virtual table]. Each subclass will 4381** be tailored to the specific needs of the module implementation. 4382** The purpose of this superclass is to define certain fields that are 4383** common to all module implementations. 4384** 4385** Virtual tables methods can set an error message by assigning a 4386** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4387** take care that any prior string is freed by a call to [sqlite3_free()] 4388** prior to assigning a new string to zErrMsg. After the error message 4389** is delivered up to the client application, the string will be automatically 4390** freed by sqlite3_free() and the zErrMsg field will be zeroed. 4391*/ 4392struct sqlite3_vtab { 4393 const sqlite3_module *pModule; /* The module for this virtual table */ 4394 int nRef; /* NO LONGER USED */ 4395 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4396 /* Virtual table implementations will typically add additional fields */ 4397}; 4398 4399/* 4400** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> 4401** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 4402** EXPERIMENTAL 4403** 4404** Every [virtual table module] implementation uses a subclass of the 4405** following structure to describe cursors that point into the 4406** [virtual table] and are used 4407** to loop through the virtual table. Cursors are created using the 4408** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 4409** by the [sqlite3_module.xClose | xClose] method. Cussors are used 4410** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 4411** of the module. Each module implementation will define 4412** the content of a cursor structure to suit its own needs. 4413** 4414** This superclass exists in order to define fields of the cursor that 4415** are common to all implementations. 4416*/ 4417struct sqlite3_vtab_cursor { 4418 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4419 /* Virtual table implementations will typically add additional fields */ 4420}; 4421 4422/* 4423** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> 4424** EXPERIMENTAL 4425** 4426** The [xCreate] and [xConnect] methods of a 4427** [virtual table module] call this interface 4428** to declare the format (the names and datatypes of the columns) of 4429** the virtual tables they implement. 4430*/ 4431SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 4432 4433/* 4434** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> 4435** EXPERIMENTAL 4436** 4437** Virtual tables can provide alternative implementations of functions 4438** using the [xFindFunction] method of the [virtual table module]. 4439** But global versions of those functions 4440** must exist in order to be overloaded. 4441** 4442** This API makes sure a global version of a function with a particular 4443** name and number of parameters exists. If no such function exists 4444** before this API is called, a new function is created. The implementation 4445** of the new function always causes an exception to be thrown. So 4446** the new function is not good for anything by itself. Its only 4447** purpose is to be a placeholder function that can be overloaded 4448** by a [virtual table]. 4449*/ 4450SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4451 4452/* 4453** The interface to the virtual-table mechanism defined above (back up 4454** to a comment remarkably similar to this one) is currently considered 4455** to be experimental. The interface might change in incompatible ways. 4456** If this is a problem for you, do not use the interface at this time. 4457** 4458** When the virtual-table mechanism stabilizes, we will declare the 4459** interface fixed, support it indefinitely, and remove this comment. 4460** 4461****** EXPERIMENTAL - subject to change without notice ************** 4462*/ 4463 4464/* 4465** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> 4466** KEYWORDS: {BLOB handle} {BLOB handles} 4467** 4468** An instance of this object represents an open BLOB on which 4469** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4470** Objects of this type are created by [sqlite3_blob_open()] 4471** and destroyed by [sqlite3_blob_close()]. 4472** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4473** can be used to read or write small subsections of the BLOB. 4474** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4475*/ 4476typedef struct sqlite3_blob sqlite3_blob; 4477 4478/* 4479** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> 4480** 4481** This interfaces opens a [BLOB handle | handle] to the BLOB located 4482** in row iRow, column zColumn, table zTable in database zDb; 4483** in other words, the same BLOB that would be selected by: 4484** 4485** <pre> 4486** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4487** </pre> {END} 4488** 4489** If the flags parameter is non-zero, then the BLOB is opened for read 4490** and write access. If it is zero, the BLOB is opened for read access. 4491** 4492** Note that the database name is not the filename that contains 4493** the database but rather the symbolic name of the database that 4494** is assigned when the database is connected using [ATTACH]. 4495** For the main database file, the database name is "main". 4496** For TEMP tables, the database name is "temp". 4497** 4498** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4499** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 4500** to be a null pointer. 4501** This function sets the [database connection] error code and message 4502** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 4503** functions. Note that the *ppBlob variable is always initialized in a 4504** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 4505** regardless of the success or failure of this routine. 4506** 4507** If the row that a BLOB handle points to is modified by an 4508** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4509** then the BLOB handle is marked as "expired". 4510** This is true if any column of the row is changed, even a column 4511** other than the one the BLOB handle is open on. 4512** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4513** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. 4514** Changes written into a BLOB prior to the BLOB expiring are not 4515** rollback by the expiration of the BLOB. Such changes will eventually 4516** commit if the transaction continues to completion. 4517** 4518** Use the [sqlite3_blob_bytes()] interface to determine the size of 4519** the opened blob. The size of a blob may not be changed by this 4520** interface. Use the [UPDATE] SQL command to change the size of a 4521** blob. 4522** 4523** The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 4524** and the built-in [zeroblob] SQL function can be used, if desired, 4525** to create an empty, zero-filled blob in which to read or write using 4526** this interface. 4527** 4528** To avoid a resource leak, every open [BLOB handle] should eventually 4529** be released by a call to [sqlite3_blob_close()]. 4530** 4531** Requirements: 4532** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] 4533*/ 4534int sqlite3_blob_open( 4535 sqlite3*, 4536 const char *zDb, 4537 const char *zTable, 4538 const char *zColumn, 4539 sqlite3_int64 iRow, 4540 int flags, 4541 sqlite3_blob **ppBlob 4542); 4543 4544/* 4545** CAPI3REF: Close A BLOB Handle {H17830} <S30230> 4546** 4547** Closes an open [BLOB handle]. 4548** 4549** Closing a BLOB shall cause the current transaction to commit 4550** if there are no other BLOBs, no pending prepared statements, and the 4551** database connection is in [autocommit mode]. 4552** If any writes were made to the BLOB, they might be held in cache 4553** until the close operation if they will fit. 4554** 4555** Closing the BLOB often forces the changes 4556** out to disk and so if any I/O errors occur, they will likely occur 4557** at the time when the BLOB is closed. Any errors that occur during 4558** closing are reported as a non-zero return value. 4559** 4560** The BLOB is closed unconditionally. Even if this routine returns 4561** an error code, the BLOB is still closed. 4562** 4563** Calling this routine with a null pointer (which as would be returned 4564** by failed call to [sqlite3_blob_open()]) is a harmless no-op. 4565** 4566** Requirements: 4567** [H17833] [H17836] [H17839] 4568*/ 4569int sqlite3_blob_close(sqlite3_blob *); 4570 4571/* 4572** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> 4573** 4574** Returns the size in bytes of the BLOB accessible via the 4575** successfully opened [BLOB handle] in its only argument. The 4576** incremental blob I/O routines can only read or overwriting existing 4577** blob content; they cannot change the size of a blob. 4578** 4579** This routine only works on a [BLOB handle] which has been created 4580** by a prior successful call to [sqlite3_blob_open()] and which has not 4581** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4582** to this routine results in undefined and probably undesirable behavior. 4583** 4584** Requirements: 4585** [H17843] 4586*/ 4587int sqlite3_blob_bytes(sqlite3_blob *); 4588 4589/* 4590** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> 4591** 4592** This function is used to read data from an open [BLOB handle] into a 4593** caller-supplied buffer. N bytes of data are copied into buffer Z 4594** from the open BLOB, starting at offset iOffset. 4595** 4596** If offset iOffset is less than N bytes from the end of the BLOB, 4597** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 4598** less than zero, [SQLITE_ERROR] is returned and no data is read. 4599** The size of the blob (and hence the maximum value of N+iOffset) 4600** can be determined using the [sqlite3_blob_bytes()] interface. 4601** 4602** An attempt to read from an expired [BLOB handle] fails with an 4603** error code of [SQLITE_ABORT]. 4604** 4605** On success, SQLITE_OK is returned. 4606** Otherwise, an [error code] or an [extended error code] is returned. 4607** 4608** This routine only works on a [BLOB handle] which has been created 4609** by a prior successful call to [sqlite3_blob_open()] and which has not 4610** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4611** to this routine results in undefined and probably undesirable behavior. 4612** 4613** See also: [sqlite3_blob_write()]. 4614** 4615** Requirements: 4616** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] 4617*/ 4618int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 4619 4620/* 4621** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> 4622** 4623** This function is used to write data into an open [BLOB handle] from a 4624** caller-supplied buffer. N bytes of data are copied from the buffer Z 4625** into the open BLOB, starting at offset iOffset. 4626** 4627** If the [BLOB handle] passed as the first argument was not opened for 4628** writing (the flags parameter to [sqlite3_blob_open()] was zero), 4629** this function returns [SQLITE_READONLY]. 4630** 4631** This function may only modify the contents of the BLOB; it is 4632** not possible to increase the size of a BLOB using this API. 4633** If offset iOffset is less than N bytes from the end of the BLOB, 4634** [SQLITE_ERROR] is returned and no data is written. If N is 4635** less than zero [SQLITE_ERROR] is returned and no data is written. 4636** The size of the BLOB (and hence the maximum value of N+iOffset) 4637** can be determined using the [sqlite3_blob_bytes()] interface. 4638** 4639** An attempt to write to an expired [BLOB handle] fails with an 4640** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred 4641** before the [BLOB handle] expired are not rolled back by the 4642** expiration of the handle, though of course those changes might 4643** have been overwritten by the statement that expired the BLOB handle 4644** or by other independent statements. 4645** 4646** On success, SQLITE_OK is returned. 4647** Otherwise, an [error code] or an [extended error code] is returned. 4648** 4649** This routine only works on a [BLOB handle] which has been created 4650** by a prior successful call to [sqlite3_blob_open()] and which has not 4651** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4652** to this routine results in undefined and probably undesirable behavior. 4653** 4654** See also: [sqlite3_blob_read()]. 4655** 4656** Requirements: 4657** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] 4658** [H17888] 4659*/ 4660int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 4661 4662/* 4663** CAPI3REF: Virtual File System Objects {H11200} <S20100> 4664** 4665** A virtual filesystem (VFS) is an [sqlite3_vfs] object 4666** that SQLite uses to interact 4667** with the underlying operating system. Most SQLite builds come with a 4668** single default VFS that is appropriate for the host computer. 4669** New VFSes can be registered and existing VFSes can be unregistered. 4670** The following interfaces are provided. 4671** 4672** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 4673** Names are case sensitive. 4674** Names are zero-terminated UTF-8 strings. 4675** If there is no match, a NULL pointer is returned. 4676** If zVfsName is NULL then the default VFS is returned. 4677** 4678** New VFSes are registered with sqlite3_vfs_register(). 4679** Each new VFS becomes the default VFS if the makeDflt flag is set. 4680** The same VFS can be registered multiple times without injury. 4681** To make an existing VFS into the default VFS, register it again 4682** with the makeDflt flag set. If two different VFSes with the 4683** same name are registered, the behavior is undefined. If a 4684** VFS is registered with a name that is NULL or an empty string, 4685** then the behavior is undefined. 4686** 4687** Unregister a VFS with the sqlite3_vfs_unregister() interface. 4688** If the default VFS is unregistered, another VFS is chosen as 4689** the default. The choice for the new VFS is arbitrary. 4690** 4691** Requirements: 4692** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] 4693*/ 4694sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 4695int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 4696int sqlite3_vfs_unregister(sqlite3_vfs*); 4697 4698/* 4699** CAPI3REF: Mutexes {H17000} <S20000> 4700** 4701** The SQLite core uses these routines for thread 4702** synchronization. Though they are intended for internal 4703** use by SQLite, code that links against SQLite is 4704** permitted to use any of these routines. 4705** 4706** The SQLite source code contains multiple implementations 4707** of these mutex routines. An appropriate implementation 4708** is selected automatically at compile-time. The following 4709** implementations are available in the SQLite core: 4710** 4711** <ul> 4712** <li> SQLITE_MUTEX_OS2 4713** <li> SQLITE_MUTEX_PTHREAD 4714** <li> SQLITE_MUTEX_W32 4715** <li> SQLITE_MUTEX_NOOP 4716** </ul> 4717** 4718** The SQLITE_MUTEX_NOOP implementation is a set of routines 4719** that does no real locking and is appropriate for use in 4720** a single-threaded application. The SQLITE_MUTEX_OS2, 4721** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 4722** are appropriate for use on OS/2, Unix, and Windows. 4723** 4724** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 4725** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 4726** implementation is included with the library. In this case the 4727** application must supply a custom mutex implementation using the 4728** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 4729** before calling sqlite3_initialize() or any other public sqlite3_ 4730** function that calls sqlite3_initialize(). 4731** 4732** {H17011} The sqlite3_mutex_alloc() routine allocates a new 4733** mutex and returns a pointer to it. {H17012} If it returns NULL 4734** that means that a mutex could not be allocated. {H17013} SQLite 4735** will unwind its stack and return an error. {H17014} The argument 4736** to sqlite3_mutex_alloc() is one of these integer constants: 4737** 4738** <ul> 4739** <li> SQLITE_MUTEX_FAST 4740** <li> SQLITE_MUTEX_RECURSIVE 4741** <li> SQLITE_MUTEX_STATIC_MASTER 4742** <li> SQLITE_MUTEX_STATIC_MEM 4743** <li> SQLITE_MUTEX_STATIC_MEM2 4744** <li> SQLITE_MUTEX_STATIC_PRNG 4745** <li> SQLITE_MUTEX_STATIC_LRU 4746** <li> SQLITE_MUTEX_STATIC_LRU2 4747** </ul> 4748** 4749** {H17015} The first two constants cause sqlite3_mutex_alloc() to create 4750** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 4751** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 4752** The mutex implementation does not need to make a distinction 4753** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 4754** not want to. {H17016} But SQLite will only request a recursive mutex in 4755** cases where it really needs one. {END} If a faster non-recursive mutex 4756** implementation is available on the host platform, the mutex subsystem 4757** might return such a mutex in response to SQLITE_MUTEX_FAST. 4758** 4759** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return 4760** a pointer to a static preexisting mutex. {END} Six static mutexes are 4761** used by the current version of SQLite. Future versions of SQLite 4762** may add additional static mutexes. Static mutexes are for internal 4763** use by SQLite only. Applications that use SQLite mutexes should 4764** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 4765** SQLITE_MUTEX_RECURSIVE. 4766** 4767** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 4768** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 4769** returns a different mutex on every call. {H17034} But for the static 4770** mutex types, the same mutex is returned on every call that has 4771** the same type number. 4772** 4773** {H17019} The sqlite3_mutex_free() routine deallocates a previously 4774** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every 4775** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in 4776** use when they are deallocated. {A17022} Attempting to deallocate a static 4777** mutex results in undefined behavior. {H17023} SQLite never deallocates 4778** a static mutex. {END} 4779** 4780** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 4781** to enter a mutex. {H17024} If another thread is already within the mutex, 4782** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 4783** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] 4784** upon successful entry. {H17026} Mutexes created using 4785** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 4786** {H17027} In such cases the, 4787** mutex must be exited an equal number of times before another thread 4788** can enter. {A17028} If the same thread tries to enter any other 4789** kind of mutex more than once, the behavior is undefined. 4790** {H17029} SQLite will never exhibit 4791** such behavior in its own use of mutexes. 4792** 4793** Some systems (for example, Windows 95) do not support the operation 4794** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 4795** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses 4796** sqlite3_mutex_try() as an optimization so this is acceptable behavior. 4797** 4798** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was 4799** previously entered by the same thread. {A17032} The behavior 4800** is undefined if the mutex is not currently entered by the 4801** calling thread or is not currently allocated. {H17033} SQLite will 4802** never do either. {END} 4803** 4804** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 4805** sqlite3_mutex_leave() is a NULL pointer, then all three routines 4806** behave as no-ops. 4807** 4808** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 4809*/ 4810sqlite3_mutex *sqlite3_mutex_alloc(int); 4811void sqlite3_mutex_free(sqlite3_mutex*); 4812void sqlite3_mutex_enter(sqlite3_mutex*); 4813int sqlite3_mutex_try(sqlite3_mutex*); 4814void sqlite3_mutex_leave(sqlite3_mutex*); 4815 4816/* 4817** CAPI3REF: Mutex Methods Object {H17120} <S20130> 4818** EXPERIMENTAL 4819** 4820** An instance of this structure defines the low-level routines 4821** used to allocate and use mutexes. 4822** 4823** Usually, the default mutex implementations provided by SQLite are 4824** sufficient, however the user has the option of substituting a custom 4825** implementation for specialized deployments or systems for which SQLite 4826** does not provide a suitable implementation. In this case, the user 4827** creates and populates an instance of this structure to pass 4828** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 4829** Additionally, an instance of this structure can be used as an 4830** output variable when querying the system for the current mutex 4831** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 4832** 4833** The xMutexInit method defined by this structure is invoked as 4834** part of system initialization by the sqlite3_initialize() function. 4835** {H17001} The xMutexInit routine shall be called by SQLite once for each 4836** effective call to [sqlite3_initialize()]. 4837** 4838** The xMutexEnd method defined by this structure is invoked as 4839** part of system shutdown by the sqlite3_shutdown() function. The 4840** implementation of this method is expected to release all outstanding 4841** resources obtained by the mutex methods implementation, especially 4842** those obtained by the xMutexInit method. {H17003} The xMutexEnd() 4843** interface shall be invoked once for each call to [sqlite3_shutdown()]. 4844** 4845** The remaining seven methods defined by this structure (xMutexAlloc, 4846** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 4847** xMutexNotheld) implement the following interfaces (respectively): 4848** 4849** <ul> 4850** <li> [sqlite3_mutex_alloc()] </li> 4851** <li> [sqlite3_mutex_free()] </li> 4852** <li> [sqlite3_mutex_enter()] </li> 4853** <li> [sqlite3_mutex_try()] </li> 4854** <li> [sqlite3_mutex_leave()] </li> 4855** <li> [sqlite3_mutex_held()] </li> 4856** <li> [sqlite3_mutex_notheld()] </li> 4857** </ul> 4858** 4859** The only difference is that the public sqlite3_XXX functions enumerated 4860** above silently ignore any invocations that pass a NULL pointer instead 4861** of a valid mutex handle. The implementations of the methods defined 4862** by this structure are not required to handle this case, the results 4863** of passing a NULL pointer instead of a valid mutex handle are undefined 4864** (i.e. it is acceptable to provide an implementation that segfaults if 4865** it is passed a NULL pointer). 4866** 4867** The xMutexInit() method must be threadsafe. It must be harmless to 4868** invoke xMutexInit() mutiple times within the same process and without 4869** intervening calls to xMutexEnd(). Second and subsequent calls to 4870** xMutexInit() must be no-ops. 4871** 4872** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 4873** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 4874** allocation for a static mutex. However xMutexAlloc() may use SQLite 4875** memory allocation for a fast or recursive mutex. 4876** 4877** SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 4878** called, but only if the prior call to xMutexInit returned SQLITE_OK. 4879** If xMutexInit fails in any way, it is expected to clean up after itself 4880** prior to returning. 4881*/ 4882typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 4883struct sqlite3_mutex_methods { 4884 int (*xMutexInit)(void); 4885 int (*xMutexEnd)(void); 4886 sqlite3_mutex *(*xMutexAlloc)(int); 4887 void (*xMutexFree)(sqlite3_mutex *); 4888 void (*xMutexEnter)(sqlite3_mutex *); 4889 int (*xMutexTry)(sqlite3_mutex *); 4890 void (*xMutexLeave)(sqlite3_mutex *); 4891 int (*xMutexHeld)(sqlite3_mutex *); 4892 int (*xMutexNotheld)(sqlite3_mutex *); 4893}; 4894 4895/* 4896** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> 4897** 4898** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 4899** are intended for use inside assert() statements. {H17081} The SQLite core 4900** never uses these routines except inside an assert() and applications 4901** are advised to follow the lead of the core. {H17082} The core only 4902** provides implementations for these routines when it is compiled 4903** with the SQLITE_DEBUG flag. {A17087} External mutex implementations 4904** are only required to provide these routines if SQLITE_DEBUG is 4905** defined and if NDEBUG is not defined. 4906** 4907** {H17083} These routines should return true if the mutex in their argument 4908** is held or not held, respectively, by the calling thread. 4909** 4910** {X17084} The implementation is not required to provided versions of these 4911** routines that actually work. If the implementation does not provide working 4912** versions of these routines, it should at least provide stubs that always 4913** return true so that one does not get spurious assertion failures. 4914** 4915** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 4916** the routine should return 1. {END} This seems counter-intuitive since 4917** clearly the mutex cannot be held if it does not exist. But the 4918** the reason the mutex does not exist is because the build is not 4919** using mutexes. And we do not want the assert() containing the 4920** call to sqlite3_mutex_held() to fail, so a non-zero return is 4921** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() 4922** interface should also return 1 when given a NULL pointer. 4923*/ 4924int sqlite3_mutex_held(sqlite3_mutex*); 4925int sqlite3_mutex_notheld(sqlite3_mutex*); 4926 4927/* 4928** CAPI3REF: Mutex Types {H17001} <H17000> 4929** 4930** The [sqlite3_mutex_alloc()] interface takes a single argument 4931** which is one of these integer constants. 4932** 4933** The set of static mutexes may change from one SQLite release to the 4934** next. Applications that override the built-in mutex logic must be 4935** prepared to accommodate additional static mutexes. 4936*/ 4937#define SQLITE_MUTEX_FAST 0 4938#define SQLITE_MUTEX_RECURSIVE 1 4939#define SQLITE_MUTEX_STATIC_MASTER 2 4940#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 4941#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 4942#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 4943#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 4944#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 4945#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 4946 4947/* 4948** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> 4949** 4950** This interface returns a pointer the [sqlite3_mutex] object that 4951** serializes access to the [database connection] given in the argument 4952** when the [threading mode] is Serialized. 4953** If the [threading mode] is Single-thread or Multi-thread then this 4954** routine returns a NULL pointer. 4955*/ 4956sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 4957 4958/* 4959** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> 4960** 4961** {H11301} The [sqlite3_file_control()] interface makes a direct call to the 4962** xFileControl method for the [sqlite3_io_methods] object associated 4963** with a particular database identified by the second argument. {H11302} The 4964** name of the database is the name assigned to the database by the 4965** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 4966** database. {H11303} To control the main database file, use the name "main" 4967** or a NULL pointer. {H11304} The third and fourth parameters to this routine 4968** are passed directly through to the second and third parameters of 4969** the xFileControl method. {H11305} The return value of the xFileControl 4970** method becomes the return value of this routine. 4971** 4972** {H11306} If the second parameter (zDbName) does not match the name of any 4973** open database file, then SQLITE_ERROR is returned. {H11307} This error 4974** code is not remembered and will not be recalled by [sqlite3_errcode()] 4975** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might 4976** also return SQLITE_ERROR. {A11309} There is no way to distinguish between 4977** an incorrect zDbName and an SQLITE_ERROR return from the underlying 4978** xFileControl method. {END} 4979** 4980** See also: [SQLITE_FCNTL_LOCKSTATE] 4981*/ 4982int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 4983 4984/* 4985** CAPI3REF: Testing Interface {H11400} <S30800> 4986** 4987** The sqlite3_test_control() interface is used to read out internal 4988** state of SQLite and to inject faults into SQLite for testing 4989** purposes. The first parameter is an operation code that determines 4990** the number, meaning, and operation of all subsequent parameters. 4991** 4992** This interface is not for use by applications. It exists solely 4993** for verifying the correct operation of the SQLite library. Depending 4994** on how the SQLite library is compiled, this interface might not exist. 4995** 4996** The details of the operation codes, their meanings, the parameters 4997** they take, and what they do are all subject to change without notice. 4998** Unlike most of the SQLite API, this function is not guaranteed to 4999** operate consistently from one release to the next. 5000*/ 5001int sqlite3_test_control(int op, ...); 5002 5003/* 5004** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> 5005** 5006** These constants are the valid operation code parameters used 5007** as the first argument to [sqlite3_test_control()]. 5008** 5009** These parameters and their meanings are subject to change 5010** without notice. These values are for testing purposes only. 5011** Applications should not use any of these parameters or the 5012** [sqlite3_test_control()] interface. 5013*/ 5014#define SQLITE_TESTCTRL_PRNG_SAVE 5 5015#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5016#define SQLITE_TESTCTRL_PRNG_RESET 7 5017#define SQLITE_TESTCTRL_BITVEC_TEST 8 5018#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5019#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5020#define SQLITE_TESTCTRL_PENDING_BYTE 11 5021#define SQLITE_TESTCTRL_ASSERT 12 5022#define SQLITE_TESTCTRL_ALWAYS 13 5023#define SQLITE_TESTCTRL_RESERVE 14 5024 5025/* 5026** CAPI3REF: SQLite Runtime Status {H17200} <S60200> 5027** EXPERIMENTAL 5028** 5029** This interface is used to retrieve runtime status information 5030** about the preformance of SQLite, and optionally to reset various 5031** highwater marks. The first argument is an integer code for 5032** the specific parameter to measure. Recognized integer codes 5033** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. 5034** The current value of the parameter is returned into *pCurrent. 5035** The highest recorded value is returned in *pHighwater. If the 5036** resetFlag is true, then the highest record value is reset after 5037** *pHighwater is written. Some parameters do not record the highest 5038** value. For those parameters 5039** nothing is written into *pHighwater and the resetFlag is ignored. 5040** Other parameters record only the highwater mark and not the current 5041** value. For these latter parameters nothing is written into *pCurrent. 5042** 5043** This routine returns SQLITE_OK on success and a non-zero 5044** [error code] on failure. 5045** 5046** This routine is threadsafe but is not atomic. This routine can be 5047** called while other threads are running the same or different SQLite 5048** interfaces. However the values returned in *pCurrent and 5049** *pHighwater reflect the status of SQLite at different points in time 5050** and it is possible that another thread might change the parameter 5051** in between the times when *pCurrent and *pHighwater are written. 5052** 5053** See also: [sqlite3_db_status()] 5054*/ 5055SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5056 5057 5058/* 5059** CAPI3REF: Status Parameters {H17250} <H17200> 5060** EXPERIMENTAL 5061** 5062** These integer constants designate various run-time status parameters 5063** that can be returned by [sqlite3_status()]. 5064** 5065** <dl> 5066** <dt>SQLITE_STATUS_MEMORY_USED</dt> 5067** <dd>This parameter is the current amount of memory checked out 5068** using [sqlite3_malloc()], either directly or indirectly. The 5069** figure includes calls made to [sqlite3_malloc()] by the application 5070** and internal memory usage by the SQLite library. Scratch memory 5071** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5072** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5073** this parameter. The amount returned is the sum of the allocation 5074** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> 5075** 5076** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5077** <dd>This parameter records the largest memory allocation request 5078** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5079** internal equivalents). Only the value returned in the 5080** *pHighwater parameter to [sqlite3_status()] is of interest. 5081** The value written into the *pCurrent parameter is undefined.</dd> 5082** 5083** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5084** <dd>This parameter returns the number of pages used out of the 5085** [pagecache memory allocator] that was configured using 5086** [SQLITE_CONFIG_PAGECACHE]. The 5087** value returned is in pages, not in bytes.</dd> 5088** 5089** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5090** <dd>This parameter returns the number of bytes of page cache 5091** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] 5092** buffer and where forced to overflow to [sqlite3_malloc()]. The 5093** returned value includes allocations that overflowed because they 5094** where too large (they were larger than the "sz" parameter to 5095** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5096** no space was left in the page cache.</dd> 5097** 5098** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5099** <dd>This parameter records the largest memory allocation request 5100** handed to [pagecache memory allocator]. Only the value returned in the 5101** *pHighwater parameter to [sqlite3_status()] is of interest. 5102** The value written into the *pCurrent parameter is undefined.</dd> 5103** 5104** <dt>SQLITE_STATUS_SCRATCH_USED</dt> 5105** <dd>This parameter returns the number of allocations used out of the 5106** [scratch memory allocator] configured using 5107** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5108** in bytes. Since a single thread may only have one scratch allocation 5109** outstanding at time, this parameter also reports the number of threads 5110** using scratch memory at the same time.</dd> 5111** 5112** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5113** <dd>This parameter returns the number of bytes of scratch memory 5114** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] 5115** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5116** returned include overflows because the requested allocation was too 5117** larger (that is, because the requested allocation was larger than the 5118** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5119** slots were available. 5120** </dd> 5121** 5122** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5123** <dd>This parameter records the largest memory allocation request 5124** handed to [scratch memory allocator]. Only the value returned in the 5125** *pHighwater parameter to [sqlite3_status()] is of interest. 5126** The value written into the *pCurrent parameter is undefined.</dd> 5127** 5128** <dt>SQLITE_STATUS_PARSER_STACK</dt> 5129** <dd>This parameter records the deepest parser stack. It is only 5130** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> 5131** </dl> 5132** 5133** New status parameters may be added from time to time. 5134*/ 5135#define SQLITE_STATUS_MEMORY_USED 0 5136#define SQLITE_STATUS_PAGECACHE_USED 1 5137#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5138#define SQLITE_STATUS_SCRATCH_USED 3 5139#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5140#define SQLITE_STATUS_MALLOC_SIZE 5 5141#define SQLITE_STATUS_PARSER_STACK 6 5142#define SQLITE_STATUS_PAGECACHE_SIZE 7 5143#define SQLITE_STATUS_SCRATCH_SIZE 8 5144 5145/* 5146** CAPI3REF: Database Connection Status {H17500} <S60200> 5147** EXPERIMENTAL 5148** 5149** This interface is used to retrieve runtime status information 5150** about a single [database connection]. The first argument is the 5151** database connection object to be interrogated. The second argument 5152** is the parameter to interrogate. Currently, the only allowed value 5153** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. 5154** Additional options will likely appear in future releases of SQLite. 5155** 5156** The current value of the requested parameter is written into *pCur 5157** and the highest instantaneous value is written into *pHiwtr. If 5158** the resetFlg is true, then the highest instantaneous value is 5159** reset back down to the current value. 5160** 5161** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5162*/ 5163SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5164 5165/* 5166** CAPI3REF: Status Parameters for database connections {H17520} <H17500> 5167** EXPERIMENTAL 5168** 5169** These constants are the available integer "verbs" that can be passed as 5170** the second argument to the [sqlite3_db_status()] interface. 5171** 5172** New verbs may be added in future releases of SQLite. Existing verbs 5173** might be discontinued. Applications should check the return code from 5174** [sqlite3_db_status()] to make sure that the call worked. 5175** The [sqlite3_db_status()] interface will return a non-zero error code 5176** if a discontinued or unsupported verb is invoked. 5177** 5178** <dl> 5179** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 5180** <dd>This parameter returns the number of lookaside memory slots currently 5181** checked out.</dd> 5182** </dl> 5183*/ 5184#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 5185 5186 5187/* 5188** CAPI3REF: Prepared Statement Status {H17550} <S60200> 5189** EXPERIMENTAL 5190** 5191** Each prepared statement maintains various 5192** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 5193** of times it has performed specific operations. These counters can 5194** be used to monitor the performance characteristics of the prepared 5195** statements. For example, if the number of table steps greatly exceeds 5196** the number of table searches or result rows, that would tend to indicate 5197** that the prepared statement is using a full table scan rather than 5198** an index. 5199** 5200** This interface is used to retrieve and reset counter values from 5201** a [prepared statement]. The first argument is the prepared statement 5202** object to be interrogated. The second argument 5203** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 5204** to be interrogated. 5205** The current value of the requested counter is returned. 5206** If the resetFlg is true, then the counter is reset to zero after this 5207** interface call returns. 5208** 5209** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5210*/ 5211SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5212 5213/* 5214** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> 5215** EXPERIMENTAL 5216** 5217** These preprocessor macros define integer codes that name counter 5218** values associated with the [sqlite3_stmt_status()] interface. 5219** The meanings of the various counters are as follows: 5220** 5221** <dl> 5222** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5223** <dd>This is the number of times that SQLite has stepped forward in 5224** a table as part of a full table scan. Large numbers for this counter 5225** may indicate opportunities for performance improvement through 5226** careful use of indices.</dd> 5227** 5228** <dt>SQLITE_STMTSTATUS_SORT</dt> 5229** <dd>This is the number of sort operations that have occurred. 5230** A non-zero value in this counter may indicate an opportunity to 5231** improvement performance through careful use of indices.</dd> 5232** 5233** </dl> 5234*/ 5235#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5236#define SQLITE_STMTSTATUS_SORT 2 5237 5238/* 5239** CAPI3REF: Custom Page Cache Object 5240** EXPERIMENTAL 5241** 5242** The sqlite3_pcache type is opaque. It is implemented by 5243** the pluggable module. The SQLite core has no knowledge of 5244** its size or internal structure and never deals with the 5245** sqlite3_pcache object except by holding and passing pointers 5246** to the object. 5247** 5248** See [sqlite3_pcache_methods] for additional information. 5249*/ 5250typedef struct sqlite3_pcache sqlite3_pcache; 5251 5252/* 5253** CAPI3REF: Application Defined Page Cache. 5254** KEYWORDS: {page cache} 5255** EXPERIMENTAL 5256** 5257** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5258** register an alternative page cache implementation by passing in an 5259** instance of the sqlite3_pcache_methods structure. The majority of the 5260** heap memory used by SQLite is used by the page cache to cache data read 5261** from, or ready to be written to, the database file. By implementing a 5262** custom page cache using this API, an application can control more 5263** precisely the amount of memory consumed by SQLite, the way in which 5264** that memory is allocated and released, and the policies used to 5265** determine exactly which parts of a database file are cached and for 5266** how long. 5267** 5268** The contents of the sqlite3_pcache_methods structure are copied to an 5269** internal buffer by SQLite within the call to [sqlite3_config]. Hence 5270** the application may discard the parameter after the call to 5271** [sqlite3_config()] returns. 5272** 5273** The xInit() method is called once for each call to [sqlite3_initialize()] 5274** (usually only once during the lifetime of the process). It is passed 5275** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set 5276** up global structures and mutexes required by the custom page cache 5277** implementation. 5278** 5279** The xShutdown() method is called from within [sqlite3_shutdown()], 5280** if the application invokes this API. It can be used to clean up 5281** any outstanding resources before process shutdown, if required. 5282** 5283** SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes 5284** the xInit method, so the xInit method need not be threadsafe. The 5285** xShutdown method is only called from [sqlite3_shutdown()] so it does 5286** not need to be threadsafe either. All other methods must be threadsafe 5287** in multithreaded applications. 5288** 5289** SQLite will never invoke xInit() more than once without an intervening 5290** call to xShutdown(). 5291** 5292** The xCreate() method is used to construct a new cache instance. SQLite 5293** will typically create one cache instance for each open database file, 5294** though this is not guaranteed. The 5295** first parameter, szPage, is the size in bytes of the pages that must 5296** be allocated by the cache. szPage will not be a power of two. szPage 5297** will the page size of the database file that is to be cached plus an 5298** increment (here called "R") of about 100 or 200. SQLite will use the 5299** extra R bytes on each page to store metadata about the underlying 5300** database page on disk. The value of R depends 5301** on the SQLite version, the target platform, and how SQLite was compiled. 5302** R is constant for a particular build of SQLite. The second argument to 5303** xCreate(), bPurgeable, is true if the cache being created will 5304** be used to cache database pages of a file stored on disk, or 5305** false if it is used for an in-memory database. The cache implementation 5306** does not have to do anything special based with the value of bPurgeable; 5307** it is purely advisory. On a cache where bPurgeable is false, SQLite will 5308** never invoke xUnpin() except to deliberately delete a page. 5309** In other words, a cache created with bPurgeable set to false will 5310** never contain any unpinned pages. 5311** 5312** The xCachesize() method may be called at any time by SQLite to set the 5313** suggested maximum cache-size (number of pages stored by) the cache 5314** instance passed as the first argument. This is the value configured using 5315** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, 5316** the implementation is not required to do anything with this 5317** value; it is advisory only. 5318** 5319** The xPagecount() method should return the number of pages currently 5320** stored in the cache. 5321** 5322** The xFetch() method is used to fetch a page and return a pointer to it. 5323** A 'page', in this context, is a buffer of szPage bytes aligned at an 5324** 8-byte boundary. The page to be fetched is determined by the key. The 5325** mimimum key value is 1. After it has been retrieved using xFetch, the page 5326** is considered to be "pinned". 5327** 5328** If the requested page is already in the page cache, then the page cache 5329** implementation must return a pointer to the page buffer with its content 5330** intact. If the requested page is not already in the cache, then the 5331** behavior of the cache implementation is determined by the value of the 5332** createFlag parameter passed to xFetch, according to the following table: 5333** 5334** <table border=1 width=85% align=center> 5335** <tr><th> createFlag <th> Behaviour when page is not already in cache 5336** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 5337** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 5338** Otherwise return NULL. 5339** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 5340** NULL if allocating a new page is effectively impossible. 5341** </table> 5342** 5343** SQLite will normally invoke xFetch() with a createFlag of 0 or 1. If 5344** a call to xFetch() with createFlag==1 returns NULL, then SQLite will 5345** attempt to unpin one or more cache pages by spilling the content of 5346** pinned pages to disk and synching the operating system disk cache. After 5347** attempting to unpin pages, the xFetch() method will be invoked again with 5348** a createFlag of 2. 5349** 5350** xUnpin() is called by SQLite with a pointer to a currently pinned page 5351** as its second argument. If the third parameter, discard, is non-zero, 5352** then the page should be evicted from the cache. In this case SQLite 5353** assumes that the next time the page is retrieved from the cache using 5354** the xFetch() method, it will be zeroed. If the discard parameter is 5355** zero, then the page is considered to be unpinned. The cache implementation 5356** may choose to evict unpinned pages at any time. 5357** 5358** The cache is not required to perform any reference counting. A single 5359** call to xUnpin() unpins the page regardless of the number of prior calls 5360** to xFetch(). 5361** 5362** The xRekey() method is used to change the key value associated with the 5363** page passed as the second argument from oldKey to newKey. If the cache 5364** previously contains an entry associated with newKey, it should be 5365** discarded. Any prior cache entry associated with newKey is guaranteed not 5366** to be pinned. 5367** 5368** When SQLite calls the xTruncate() method, the cache must discard all 5369** existing cache entries with page numbers (keys) greater than or equal 5370** to the value of the iLimit parameter passed to xTruncate(). If any 5371** of these pages are pinned, they are implicitly unpinned, meaning that 5372** they can be safely discarded. 5373** 5374** The xDestroy() method is used to delete a cache allocated by xCreate(). 5375** All resources associated with the specified cache should be freed. After 5376** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5377** handle invalid, and will not use it with any other sqlite3_pcache_methods 5378** functions. 5379*/ 5380typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5381struct sqlite3_pcache_methods { 5382 void *pArg; 5383 int (*xInit)(void*); 5384 void (*xShutdown)(void*); 5385 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5386 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5387 int (*xPagecount)(sqlite3_pcache*); 5388 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5389 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5390 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5391 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5392 void (*xDestroy)(sqlite3_pcache*); 5393}; 5394 5395/* 5396** CAPI3REF: Online Backup Object 5397** EXPERIMENTAL 5398** 5399** The sqlite3_backup object records state information about an ongoing 5400** online backup operation. The sqlite3_backup object is created by 5401** a call to [sqlite3_backup_init()] and is destroyed by a call to 5402** [sqlite3_backup_finish()]. 5403** 5404** See Also: [Using the SQLite Online Backup API] 5405*/ 5406typedef struct sqlite3_backup sqlite3_backup; 5407 5408/* 5409** CAPI3REF: Online Backup API. 5410** EXPERIMENTAL 5411** 5412** This API is used to overwrite the contents of one database with that 5413** of another. It is useful either for creating backups of databases or 5414** for copying in-memory databases to or from persistent files. 5415** 5416** See Also: [Using the SQLite Online Backup API] 5417** 5418** Exclusive access is required to the destination database for the 5419** duration of the operation. However the source database is only 5420** read-locked while it is actually being read, it is not locked 5421** continuously for the entire operation. Thus, the backup may be 5422** performed on a live database without preventing other users from 5423** writing to the database for an extended period of time. 5424** 5425** To perform a backup operation: 5426** <ol> 5427** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5428** backup, 5429** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5430** the data between the two databases, and finally 5431** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5432** associated with the backup operation. 5433** </ol> 5434** There should be exactly one call to sqlite3_backup_finish() for each 5435** successful call to sqlite3_backup_init(). 5436** 5437** <b>sqlite3_backup_init()</b> 5438** 5439** The first two arguments passed to [sqlite3_backup_init()] are the database 5440** handle associated with the destination database and the database name 5441** used to attach the destination database to the handle. The database name 5442** is "main" for the main database, "temp" for the temporary database, or 5443** the name specified as part of the [ATTACH] statement if the destination is 5444** an attached database. The third and fourth arguments passed to 5445** sqlite3_backup_init() identify the [database connection] 5446** and database name used 5447** to access the source database. The values passed for the source and 5448** destination [database connection] parameters must not be the same. 5449** 5450** If an error occurs within sqlite3_backup_init(), then NULL is returned 5451** and an error code and error message written into the [database connection] 5452** passed as the first argument. They may be retrieved using the 5453** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. 5454** Otherwise, if successful, a pointer to an [sqlite3_backup] object is 5455** returned. This pointer may be used with the sqlite3_backup_step() and 5456** sqlite3_backup_finish() functions to perform the specified backup 5457** operation. 5458** 5459** <b>sqlite3_backup_step()</b> 5460** 5461** Function [sqlite3_backup_step()] is used to copy up to nPage pages between 5462** the source and destination databases, where nPage is the value of the 5463** second parameter passed to sqlite3_backup_step(). If nPage is a negative 5464** value, all remaining source pages are copied. If the required pages are 5465** succesfully copied, but there are still more pages to copy before the 5466** backup is complete, it returns [SQLITE_OK]. If no error occured and there 5467** are no more pages to copy, then [SQLITE_DONE] is returned. If an error 5468** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and 5469** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5470** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5471** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5472** 5473** As well as the case where the destination database file was opened for 5474** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if 5475** the destination is an in-memory database with a different page size 5476** from the source database. 5477** 5478** If sqlite3_backup_step() cannot obtain a required file-system lock, then 5479** the [sqlite3_busy_handler | busy-handler function] 5480** is invoked (if one is specified). If the 5481** busy-handler returns non-zero before the lock is available, then 5482** [SQLITE_BUSY] is returned to the caller. In this case the call to 5483** sqlite3_backup_step() can be retried later. If the source 5484** [database connection] 5485** is being used to write to the source database when sqlite3_backup_step() 5486** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this 5487** case the call to sqlite3_backup_step() can be retried later on. If 5488** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5489** [SQLITE_READONLY] is returned, then 5490** there is no point in retrying the call to sqlite3_backup_step(). These 5491** errors are considered fatal. At this point the application must accept 5492** that the backup operation has failed and pass the backup operation handle 5493** to the sqlite3_backup_finish() to release associated resources. 5494** 5495** Following the first call to sqlite3_backup_step(), an exclusive lock is 5496** obtained on the destination file. It is not released until either 5497** sqlite3_backup_finish() is called or the backup operation is complete 5498** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time 5499** a call to sqlite3_backup_step() is made a [shared lock] is obtained on 5500** the source database file. This lock is released before the 5501** sqlite3_backup_step() call returns. Because the source database is not 5502** locked between calls to sqlite3_backup_step(), it may be modified mid-way 5503** through the backup procedure. If the source database is modified by an 5504** external process or via a database connection other than the one being 5505** used by the backup operation, then the backup will be transparently 5506** restarted by the next call to sqlite3_backup_step(). If the source 5507** database is modified by the using the same database connection as is used 5508** by the backup operation, then the backup database is transparently 5509** updated at the same time. 5510** 5511** <b>sqlite3_backup_finish()</b> 5512** 5513** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5514** application wishes to abandon the backup operation, the [sqlite3_backup] 5515** object should be passed to sqlite3_backup_finish(). This releases all 5516** resources associated with the backup operation. If sqlite3_backup_step() 5517** has not yet returned [SQLITE_DONE], then any active write-transaction on the 5518** destination database is rolled back. The [sqlite3_backup] object is invalid 5519** and may not be used following a call to sqlite3_backup_finish(). 5520** 5521** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error 5522** occurred, regardless or whether or not sqlite3_backup_step() was called 5523** a sufficient number of times to complete the backup operation. Or, if 5524** an out-of-memory condition or IO error occured during a call to 5525** sqlite3_backup_step() then [SQLITE_NOMEM] or an 5526** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code 5527** is returned. In this case the error code and an error message are 5528** written to the destination [database connection]. 5529** 5530** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is 5531** not a permanent error and does not affect the return value of 5532** sqlite3_backup_finish(). 5533** 5534** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 5535** 5536** Each call to sqlite3_backup_step() sets two values stored internally 5537** by an [sqlite3_backup] object. The number of pages still to be backed 5538** up, which may be queried by sqlite3_backup_remaining(), and the total 5539** number of pages in the source database file, which may be queried by 5540** sqlite3_backup_pagecount(). 5541** 5542** The values returned by these functions are only updated by 5543** sqlite3_backup_step(). If the source database is modified during a backup 5544** operation, then the values are not updated to account for any extra 5545** pages that need to be updated or the size of the source database file 5546** changing. 5547** 5548** <b>Concurrent Usage of Database Handles</b> 5549** 5550** The source [database connection] may be used by the application for other 5551** purposes while a backup operation is underway or being initialized. 5552** If SQLite is compiled and configured to support threadsafe database 5553** connections, then the source database connection may be used concurrently 5554** from within other threads. 5555** 5556** However, the application must guarantee that the destination database 5557** connection handle is not passed to any other API (by any thread) after 5558** sqlite3_backup_init() is called and before the corresponding call to 5559** sqlite3_backup_finish(). Unfortunately SQLite does not currently check 5560** for this, if the application does use the destination [database connection] 5561** for some other purpose during a backup operation, things may appear to 5562** work correctly but in fact be subtly malfunctioning. Use of the 5563** destination database connection while a backup is in progress might 5564** also cause a mutex deadlock. 5565** 5566** Furthermore, if running in [shared cache mode], the application must 5567** guarantee that the shared cache used by the destination database 5568** is not accessed while the backup is running. In practice this means 5569** that the application must guarantee that the file-system file being 5570** backed up to is not accessed by any connection within the process, 5571** not just the specific connection that was passed to sqlite3_backup_init(). 5572** 5573** The [sqlite3_backup] object itself is partially threadsafe. Multiple 5574** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 5575** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 5576** APIs are not strictly speaking threadsafe. If they are invoked at the 5577** same time as another thread is invoking sqlite3_backup_step() it is 5578** possible that they return invalid values. 5579*/ 5580sqlite3_backup *sqlite3_backup_init( 5581 sqlite3 *pDest, /* Destination database handle */ 5582 const char *zDestName, /* Destination database name */ 5583 sqlite3 *pSource, /* Source database handle */ 5584 const char *zSourceName /* Source database name */ 5585); 5586int sqlite3_backup_step(sqlite3_backup *p, int nPage); 5587int sqlite3_backup_finish(sqlite3_backup *p); 5588int sqlite3_backup_remaining(sqlite3_backup *p); 5589int sqlite3_backup_pagecount(sqlite3_backup *p); 5590 5591/* 5592** CAPI3REF: Unlock Notification 5593** EXPERIMENTAL 5594** 5595** When running in shared-cache mode, a database operation may fail with 5596** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 5597** individual tables within the shared-cache cannot be obtained. See 5598** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 5599** This API may be used to register a callback that SQLite will invoke 5600** when the connection currently holding the required lock relinquishes it. 5601** This API is only available if the library was compiled with the 5602** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 5603** 5604** See Also: [Using the SQLite Unlock Notification Feature]. 5605** 5606** Shared-cache locks are released when a database connection concludes 5607** its current transaction, either by committing it or rolling it back. 5608** 5609** When a connection (known as the blocked connection) fails to obtain a 5610** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 5611** identity of the database connection (the blocking connection) that 5612** has locked the required resource is stored internally. After an 5613** application receives an SQLITE_LOCKED error, it may call the 5614** sqlite3_unlock_notify() method with the blocked connection handle as 5615** the first argument to register for a callback that will be invoked 5616** when the blocking connections current transaction is concluded. The 5617** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 5618** call that concludes the blocking connections transaction. 5619** 5620** If sqlite3_unlock_notify() is called in a multi-threaded application, 5621** there is a chance that the blocking connection will have already 5622** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 5623** If this happens, then the specified callback is invoked immediately, 5624** from within the call to sqlite3_unlock_notify(). 5625** 5626** If the blocked connection is attempting to obtain a write-lock on a 5627** shared-cache table, and more than one other connection currently holds 5628** a read-lock on the same table, then SQLite arbitrarily selects one of 5629** the other connections to use as the blocking connection. 5630** 5631** There may be at most one unlock-notify callback registered by a 5632** blocked connection. If sqlite3_unlock_notify() is called when the 5633** blocked connection already has a registered unlock-notify callback, 5634** then the new callback replaces the old. If sqlite3_unlock_notify() is 5635** called with a NULL pointer as its second argument, then any existing 5636** unlock-notify callback is cancelled. The blocked connections 5637** unlock-notify callback may also be canceled by closing the blocked 5638** connection using [sqlite3_close()]. 5639** 5640** The unlock-notify callback is not reentrant. If an application invokes 5641** any sqlite3_xxx API functions from within an unlock-notify callback, a 5642** crash or deadlock may be the result. 5643** 5644** Unless deadlock is detected (see below), sqlite3_unlock_notify() always 5645** returns SQLITE_OK. 5646** 5647** <b>Callback Invocation Details</b> 5648** 5649** When an unlock-notify callback is registered, the application provides a 5650** single void* pointer that is passed to the callback when it is invoked. 5651** However, the signature of the callback function allows SQLite to pass 5652** it an array of void* context pointers. The first argument passed to 5653** an unlock-notify callback is a pointer to an array of void* pointers, 5654** and the second is the number of entries in the array. 5655** 5656** When a blocking connections transaction is concluded, there may be 5657** more than one blocked connection that has registered for an unlock-notify 5658** callback. If two or more such blocked connections have specified the 5659** same callback function, then instead of invoking the callback function 5660** multiple times, it is invoked once with the set of void* context pointers 5661** specified by the blocked connections bundled together into an array. 5662** This gives the application an opportunity to prioritize any actions 5663** related to the set of unblocked database connections. 5664** 5665** <b>Deadlock Detection</b> 5666** 5667** Assuming that after registering for an unlock-notify callback a 5668** database waits for the callback to be issued before taking any further 5669** action (a reasonable assumption), then using this API may cause the 5670** application to deadlock. For example, if connection X is waiting for 5671** connection Y's transaction to be concluded, and similarly connection 5672** Y is waiting on connection X's transaction, then neither connection 5673** will proceed and the system may remain deadlocked indefinitely. 5674** 5675** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 5676** detection. If a given call to sqlite3_unlock_notify() would put the 5677** system in a deadlocked state, then SQLITE_LOCKED is returned and no 5678** unlock-notify callback is registered. The system is said to be in 5679** a deadlocked state if connection A has registered for an unlock-notify 5680** callback on the conclusion of connection B's transaction, and connection 5681** B has itself registered for an unlock-notify callback when connection 5682** A's transaction is concluded. Indirect deadlock is also detected, so 5683** the system is also considered to be deadlocked if connection B has 5684** registered for an unlock-notify callback on the conclusion of connection 5685** C's transaction, where connection C is waiting on connection A. Any 5686** number of levels of indirection are allowed. 5687** 5688** <b>The "DROP TABLE" Exception</b> 5689** 5690** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 5691** always appropriate to call sqlite3_unlock_notify(). There is however, 5692** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 5693** SQLite checks if there are any currently executing SELECT statements 5694** that belong to the same connection. If there are, SQLITE_LOCKED is 5695** returned. In this case there is no "blocking connection", so invoking 5696** sqlite3_unlock_notify() results in the unlock-notify callback being 5697** invoked immediately. If the application then re-attempts the "DROP TABLE" 5698** or "DROP INDEX" query, an infinite loop might be the result. 5699** 5700** One way around this problem is to check the extended error code returned 5701** by an sqlite3_step() call. If there is a blocking connection, then the 5702** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 5703** the special "DROP TABLE/INDEX" case, the extended error code is just 5704** SQLITE_LOCKED. 5705*/ 5706int sqlite3_unlock_notify( 5707 sqlite3 *pBlocked, /* Waiting connection */ 5708 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 5709 void *pNotifyArg /* Argument to pass to xNotify */ 5710); 5711 5712 5713/* 5714** CAPI3REF: String Comparison 5715** EXPERIMENTAL 5716** 5717** The [sqlite3_strnicmp()] API allows applications and extensions to 5718** compare the contents of two buffers containing UTF-8 strings in a 5719** case-indendent fashion, using the same definition of case independence 5720** that SQLite uses internally when comparing identifiers. 5721*/ 5722int sqlite3_strnicmp(const char *, const char *, int); 5723 5724/* 5725** Undo the hack that converts floating point types to integer for 5726** builds on processors without floating point support. 5727*/ 5728#ifdef SQLITE_OMIT_FLOATING_POINT 5729# undef double 5730#endif 5731 5732#ifdef __cplusplus 5733} /* End of the 'extern "C"' block */ 5734#endif 5735#endif 5736