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Diffstat (limited to 'package/sqlite/src/sqlite3.h')
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diff --git a/package/sqlite/src/sqlite3.h b/package/sqlite/src/sqlite3.h new file mode 100644 index 000000000..fc015b08e --- /dev/null +++ b/package/sqlite/src/sqlite3.h @@ -0,0 +1,5772 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This header file defines the interface that the SQLite library +** presents to client programs. If a C-function, structure, datatype, +** or constant definition does not appear in this file, then it is +** not a published API of SQLite, is subject to change without +** notice, and should not be referenced by programs that use SQLite. +** +** Some of the definitions that are in this file are marked as +** "experimental". Experimental interfaces are normally new +** features recently added to SQLite. We do not anticipate changes +** to experimental interfaces but reserve the right to make minor changes +** if experience from use "in the wild" suggest such changes are prudent. +** +** The official C-language API documentation for SQLite is derived +** from comments in this file. This file is the authoritative source +** on how SQLite interfaces are suppose to operate. +** +** The name of this file under configuration management is "sqlite.h.in". +** The makefile makes some minor changes to this file (such as inserting +** the version number) and changes its name to "sqlite3.h" as +** part of the build process. +*/ +#ifndef _SQLITE3_H_ +#define _SQLITE3_H_ +#include <stdarg.h> /* Needed for the definition of va_list */ + +/* +** Make sure we can call this stuff from C++. +*/ +#ifdef __cplusplus +extern "C" { +#endif + + +/* +** Add the ability to override 'extern' +*/ +#ifndef SQLITE_EXTERN +# define SQLITE_EXTERN extern +#endif + +#ifndef SQLITE_API +# define SQLITE_API +#endif + + +/* +** These no-op macros are used in front of interfaces to mark those +** interfaces as either deprecated or experimental. New applications +** should not use deprecated interfaces - they are support for backwards +** compatibility only. Application writers should be aware that +** experimental interfaces are subject to change in point releases. +** +** These macros used to resolve to various kinds of compiler magic that +** would generate warning messages when they were used. But that +** compiler magic ended up generating such a flurry of bug reports +** that we have taken it all out and gone back to using simple +** noop macros. +*/ +#define SQLITE_DEPRECATED +#define SQLITE_EXPERIMENTAL + +/* +** Ensure these symbols were not defined by some previous header file. +*/ +#ifdef SQLITE_VERSION +# undef SQLITE_VERSION +#endif +#ifdef SQLITE_VERSION_NUMBER +# undef SQLITE_VERSION_NUMBER +#endif + +/* +** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> +** +** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in +** the sqlite3.h file specify the version of SQLite with which +** that header file is associated. +** +** The "version" of SQLite is a string of the form "W.X.Y" or "W.X.Y.Z". +** The W value is major version number and is always 3 in SQLite3. +** The W value only changes when backwards compatibility is +** broken and we intend to never break backwards compatibility. +** The X value is the minor version number and only changes when +** there are major feature enhancements that are forwards compatible +** but not backwards compatible. +** The Y value is the release number and is incremented with +** each release but resets back to 0 whenever X is incremented. +** The Z value only appears on branch releases. +** +** The SQLITE_VERSION_NUMBER is an integer that is computed as +** follows: +** +** <blockquote><pre> +** SQLITE_VERSION_NUMBER = W*1000000 + X*1000 + Y +** </pre></blockquote> +** +** Since version 3.6.18, SQLite source code has been stored in the +** <a href="http://www.fossil-scm.org/">fossil configuration management +** system</a>. The SQLITE_SOURCE_ID +** macro is a string which identifies a particular check-in of SQLite +** within its configuration management system. The string contains the +** date and time of the check-in (UTC) and an SHA1 hash of the entire +** source tree. +** +** See also: [sqlite3_libversion()], +** [sqlite3_libversion_number()], [sqlite3_sourceid()], +** [sqlite_version()] and [sqlite_source_id()]. +** +** Requirements: [H10011] [H10014] +*/ +#define SQLITE_VERSION "3.6.20" +#define SQLITE_VERSION_NUMBER 3006020 +#define SQLITE_SOURCE_ID "2009-11-04 13:30:02 eb7a544fe49d1626bacecfe53ddc03fe082e3243" + +/* +** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> +** KEYWORDS: sqlite3_version +** +** These interfaces provide the same information as the [SQLITE_VERSION], +** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] #defines in the header, +** but are associated with the library instead of the header file. Cautious +** programmers might include assert() statements in their application to +** verify that values returned by these interfaces match the macros in +** the header, and thus insure that the application is +** compiled with matching library and header files. +** +** <blockquote><pre> +** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); +** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); +** assert( strcmp(sqlite3_libversion,SQLITE_VERSION)==0 ); +** </pre></blockquote> +** +** The sqlite3_libversion() function returns the same information as is +** in the sqlite3_version[] string constant. The function is provided +** for use in DLLs since DLL users usually do not have direct access to string +** constants within the DLL. Similarly, the sqlite3_sourceid() function +** returns the same information as is in the [SQLITE_SOURCE_ID] #define of +** the header file. +** +** See also: [sqlite_version()] and [sqlite_source_id()]. +** +** Requirements: [H10021] [H10022] [H10023] +*/ +SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; +SQLITE_API const char *sqlite3_libversion(void); +SQLITE_API const char *sqlite3_sourceid(void); +SQLITE_API int sqlite3_libversion_number(void); + +/* +** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> +** +** SQLite can be compiled with or without mutexes. When +** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes +** are enabled and SQLite is threadsafe. When the +** [SQLITE_THREADSAFE] macro is 0, +** the mutexes are omitted. Without the mutexes, it is not safe +** to use SQLite concurrently from more than one thread. +** +** Enabling mutexes incurs a measurable performance penalty. +** So if speed is of utmost importance, it makes sense to disable +** the mutexes. But for maximum safety, mutexes should be enabled. +** The default behavior is for mutexes to be enabled. +** +** This interface can be used by an application to make sure that the +** version of SQLite that it is linking against was compiled with +** the desired setting of the [SQLITE_THREADSAFE] macro. +** +** This interface only reports on the compile-time mutex setting +** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with +** SQLITE_THREADSAFE=1 then mutexes are enabled by default but +** can be fully or partially disabled using a call to [sqlite3_config()] +** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], +** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows +** only the default compile-time setting, not any run-time changes +** to that setting. +** +** See the [threading mode] documentation for additional information. +** +** Requirements: [H10101] [H10102] +*/ +SQLITE_API int sqlite3_threadsafe(void); + +/* +** CAPI3REF: Database Connection Handle {H12000} <S40200> +** KEYWORDS: {database connection} {database connections} +** +** Each open SQLite database is represented by a pointer to an instance of +** the opaque structure named "sqlite3". It is useful to think of an sqlite3 +** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and +** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] +** is its destructor. There are many other interfaces (such as +** [sqlite3_prepare_v2()], [sqlite3_create_function()], and +** [sqlite3_busy_timeout()] to name but three) that are methods on an +** sqlite3 object. +*/ +typedef struct sqlite3 sqlite3; + +/* +** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> +** KEYWORDS: sqlite_int64 sqlite_uint64 +** +** Because there is no cross-platform way to specify 64-bit integer types +** SQLite includes typedefs for 64-bit signed and unsigned integers. +** +** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. +** The sqlite_int64 and sqlite_uint64 types are supported for backwards +** compatibility only. +** +** Requirements: [H10201] [H10202] +*/ +#ifdef SQLITE_INT64_TYPE + typedef SQLITE_INT64_TYPE sqlite_int64; + typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; +#elif defined(_MSC_VER) || defined(__BORLANDC__) + typedef __int64 sqlite_int64; + typedef unsigned __int64 sqlite_uint64; +#else + typedef long long int sqlite_int64; + typedef unsigned long long int sqlite_uint64; +#endif +typedef sqlite_int64 sqlite3_int64; +typedef sqlite_uint64 sqlite3_uint64; + +/* +** If compiling for a processor that lacks floating point support, +** substitute integer for floating-point. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# define double sqlite3_int64 +#endif + +/* +** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> +** +** This routine is the destructor for the [sqlite3] object. +** +** Applications must [sqlite3_finalize | finalize] all [prepared statements] +** and [sqlite3_blob_close | close] all [BLOB handles] associated with +** the [sqlite3] object prior to attempting to close the object. +** +** If [sqlite3_close()] is invoked while a transaction is open, +** the transaction is automatically rolled back. +** +** The C parameter to [sqlite3_close(C)] must be either a NULL +** pointer or an [sqlite3] object pointer obtained +** from [sqlite3_open()], [sqlite3_open16()], or +** [sqlite3_open_v2()], and not previously closed. +** +** Requirements: +** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] +*/ +SQLITE_API int sqlite3_close(sqlite3 *); + +/* +** The type for a callback function. +** This is legacy and deprecated. It is included for historical +** compatibility and is not documented. +*/ +typedef int (*sqlite3_callback)(void*,int,char**, char**); + +/* +** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> +** +** The sqlite3_exec() interface is a convenient way of running one or more +** SQL statements without having to write a lot of C code. The UTF-8 encoded +** SQL statements are passed in as the second parameter to sqlite3_exec(). +** The statements are evaluated one by one until either an error or +** an interrupt is encountered, or until they are all done. The 3rd parameter +** is an optional callback that is invoked once for each row of any query +** results produced by the SQL statements. The 5th parameter tells where +** to write any error messages. +** +** The error message passed back through the 5th parameter is held +** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, +** the calling application should call [sqlite3_free()] on any error +** message returned through the 5th parameter when it has finished using +** the error message. +** +** If the SQL statement in the 2nd parameter is NULL or an empty string +** or a string containing only whitespace and comments, then no SQL +** statements are evaluated and the database is not changed. +** +** The sqlite3_exec() interface is implemented in terms of +** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. +** The sqlite3_exec() routine does nothing to the database that cannot be done +** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. +** +** The first parameter to [sqlite3_exec()] must be an valid and open +** [database connection]. +** +** The database connection must not be closed while +** [sqlite3_exec()] is running. +** +** The calling function should use [sqlite3_free()] to free +** the memory that *errmsg is left pointing at once the error +** message is no longer needed. +** +** The SQL statement text in the 2nd parameter to [sqlite3_exec()] +** must remain unchanged while [sqlite3_exec()] is running. +** +** Requirements: +** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] +** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] +*/ +SQLITE_API int sqlite3_exec( + sqlite3*, /* An open database */ + const char *sql, /* SQL to be evaluated */ + int (*callback)(void*,int,char**,char**), /* Callback function */ + void *, /* 1st argument to callback */ + char **errmsg /* Error msg written here */ +); + +/* +** CAPI3REF: Result Codes {H10210} <S10700> +** KEYWORDS: SQLITE_OK {error code} {error codes} +** KEYWORDS: {result code} {result codes} +** +** Many SQLite functions return an integer result code from the set shown +** here in order to indicates success or failure. +** +** New error codes may be added in future versions of SQLite. +** +** See also: [SQLITE_IOERR_READ | extended result codes] +*/ +#define SQLITE_OK 0 /* Successful result */ +/* beginning-of-error-codes */ +#define SQLITE_ERROR 1 /* SQL error or missing database */ +#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ +#define SQLITE_PERM 3 /* Access permission denied */ +#define SQLITE_ABORT 4 /* Callback routine requested an abort */ +#define SQLITE_BUSY 5 /* The database file is locked */ +#define SQLITE_LOCKED 6 /* A table in the database is locked */ +#define SQLITE_NOMEM 7 /* A malloc() failed */ +#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ +#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ +#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ +#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ +#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ +#define SQLITE_FULL 13 /* Insertion failed because database is full */ +#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ +#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ +#define SQLITE_EMPTY 16 /* Database is empty */ +#define SQLITE_SCHEMA 17 /* The database schema changed */ +#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ +#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ +#define SQLITE_MISMATCH 20 /* Data type mismatch */ +#define SQLITE_MISUSE 21 /* Library used incorrectly */ +#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ +#define SQLITE_AUTH 23 /* Authorization denied */ +#define SQLITE_FORMAT 24 /* Auxiliary database format error */ +#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ +#define SQLITE_NOTADB 26 /* File opened that is not a database file */ +#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ +#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ +/* end-of-error-codes */ + +/* +** CAPI3REF: Extended Result Codes {H10220} <S10700> +** KEYWORDS: {extended error code} {extended error codes} +** KEYWORDS: {extended result code} {extended result codes} +** +** In its default configuration, SQLite API routines return one of 26 integer +** [SQLITE_OK | result codes]. However, experience has shown that many of +** these result codes are too coarse-grained. They do not provide as +** much information about problems as programmers might like. In an effort to +** address this, newer versions of SQLite (version 3.3.8 and later) include +** support for additional result codes that provide more detailed information +** about errors. The extended result codes are enabled or disabled +** on a per database connection basis using the +** [sqlite3_extended_result_codes()] API. +** +** Some of the available extended result codes are listed here. +** One may expect the number of extended result codes will be expand +** over time. Software that uses extended result codes should expect +** to see new result codes in future releases of SQLite. +** +** The SQLITE_OK result code will never be extended. It will always +** be exactly zero. +*/ +#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) +#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) +#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) +#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) +#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) +#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) +#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) +#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) +#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) +#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) +#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) +#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) +#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) +#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) +#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) +#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) +#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) +#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) + +/* +** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> +** +** These bit values are intended for use in the +** 3rd parameter to the [sqlite3_open_v2()] interface and +** in the 4th parameter to the xOpen method of the +** [sqlite3_vfs] object. +*/ +#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ +#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ +#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ +#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ +#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ +#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ +#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ +#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ +#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ +#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ + +/* +** CAPI3REF: Device Characteristics {H10240} <H11120> +** +** The xDeviceCapabilities method of the [sqlite3_io_methods] +** object returns an integer which is a vector of the these +** bit values expressing I/O characteristics of the mass storage +** device that holds the file that the [sqlite3_io_methods] +** refers to. +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). +*/ +#define SQLITE_IOCAP_ATOMIC 0x00000001 +#define SQLITE_IOCAP_ATOMIC512 0x00000002 +#define SQLITE_IOCAP_ATOMIC1K 0x00000004 +#define SQLITE_IOCAP_ATOMIC2K 0x00000008 +#define SQLITE_IOCAP_ATOMIC4K 0x00000010 +#define SQLITE_IOCAP_ATOMIC8K 0x00000020 +#define SQLITE_IOCAP_ATOMIC16K 0x00000040 +#define SQLITE_IOCAP_ATOMIC32K 0x00000080 +#define SQLITE_IOCAP_ATOMIC64K 0x00000100 +#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 +#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 + +/* +** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> +** +** SQLite uses one of these integer values as the second +** argument to calls it makes to the xLock() and xUnlock() methods +** of an [sqlite3_io_methods] object. +*/ +#define SQLITE_LOCK_NONE 0 +#define SQLITE_LOCK_SHARED 1 +#define SQLITE_LOCK_RESERVED 2 +#define SQLITE_LOCK_PENDING 3 +#define SQLITE_LOCK_EXCLUSIVE 4 + +/* +** CAPI3REF: Synchronization Type Flags {H10260} <H11120> +** +** When SQLite invokes the xSync() method of an +** [sqlite3_io_methods] object it uses a combination of +** these integer values as the second argument. +** +** When the SQLITE_SYNC_DATAONLY flag is used, it means that the +** sync operation only needs to flush data to mass storage. Inode +** information need not be flushed. If the lower four bits of the flag +** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. +** If the lower four bits equal SQLITE_SYNC_FULL, that means +** to use Mac OS X style fullsync instead of fsync(). +*/ +#define SQLITE_SYNC_NORMAL 0x00002 +#define SQLITE_SYNC_FULL 0x00003 +#define SQLITE_SYNC_DATAONLY 0x00010 + +/* +** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> +** +** An [sqlite3_file] object represents an open file in the +** [sqlite3_vfs | OS interface layer]. Individual OS interface +** implementations will +** want to subclass this object by appending additional fields +** for their own use. The pMethods entry is a pointer to an +** [sqlite3_io_methods] object that defines methods for performing +** I/O operations on the open file. +*/ +typedef struct sqlite3_file sqlite3_file; +struct sqlite3_file { + const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ +}; + +/* +** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> +** +** Every file opened by the [sqlite3_vfs] xOpen method populates an +** [sqlite3_file] object (or, more commonly, a subclass of the +** [sqlite3_file] object) with a pointer to an instance of this object. +** This object defines the methods used to perform various operations +** against the open file represented by the [sqlite3_file] object. +** +** If the xOpen method sets the sqlite3_file.pMethods element +** to a non-NULL pointer, then the sqlite3_io_methods.xClose method +** may be invoked even if the xOpen reported that it failed. The +** only way to prevent a call to xClose following a failed xOpen +** is for the xOpen to set the sqlite3_file.pMethods element to NULL. +** +** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or +** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). +** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] +** flag may be ORed in to indicate that only the data of the file +** and not its inode needs to be synced. +** +** The integer values to xLock() and xUnlock() are one of +** <ul> +** <li> [SQLITE_LOCK_NONE], +** <li> [SQLITE_LOCK_SHARED], +** <li> [SQLITE_LOCK_RESERVED], +** <li> [SQLITE_LOCK_PENDING], or +** <li> [SQLITE_LOCK_EXCLUSIVE]. +** </ul> +** xLock() increases the lock. xUnlock() decreases the lock. +** The xCheckReservedLock() method checks whether any database connection, +** either in this process or in some other process, is holding a RESERVED, +** PENDING, or EXCLUSIVE lock on the file. It returns true +** if such a lock exists and false otherwise. +** +** The xFileControl() method is a generic interface that allows custom +** VFS implementations to directly control an open file using the +** [sqlite3_file_control()] interface. The second "op" argument is an +** integer opcode. The third argument is a generic pointer intended to +** point to a structure that may contain arguments or space in which to +** write return values. Potential uses for xFileControl() might be +** functions to enable blocking locks with timeouts, to change the +** locking strategy (for example to use dot-file locks), to inquire +** about the status of a lock, or to break stale locks. The SQLite +** core reserves all opcodes less than 100 for its own use. +** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. +** Applications that define a custom xFileControl method should use opcodes +** greater than 100 to avoid conflicts. +** +** The xSectorSize() method returns the sector size of the +** device that underlies the file. The sector size is the +** minimum write that can be performed without disturbing +** other bytes in the file. The xDeviceCharacteristics() +** method returns a bit vector describing behaviors of the +** underlying device: +** +** <ul> +** <li> [SQLITE_IOCAP_ATOMIC] +** <li> [SQLITE_IOCAP_ATOMIC512] +** <li> [SQLITE_IOCAP_ATOMIC1K] +** <li> [SQLITE_IOCAP_ATOMIC2K] +** <li> [SQLITE_IOCAP_ATOMIC4K] +** <li> [SQLITE_IOCAP_ATOMIC8K] +** <li> [SQLITE_IOCAP_ATOMIC16K] +** <li> [SQLITE_IOCAP_ATOMIC32K] +** <li> [SQLITE_IOCAP_ATOMIC64K] +** <li> [SQLITE_IOCAP_SAFE_APPEND] +** <li> [SQLITE_IOCAP_SEQUENTIAL] +** </ul> +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). +** +** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill +** in the unread portions of the buffer with zeros. A VFS that +** fails to zero-fill short reads might seem to work. However, +** failure to zero-fill short reads will eventually lead to +** database corruption. +*/ +typedef struct sqlite3_io_methods sqlite3_io_methods; +struct sqlite3_io_methods { + int iVersion; + int (*xClose)(sqlite3_file*); + int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); + int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); + int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); + int (*xSync)(sqlite3_file*, int flags); + int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); + int (*xLock)(sqlite3_file*, int); + int (*xUnlock)(sqlite3_file*, int); + int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); + int (*xFileControl)(sqlite3_file*, int op, void *pArg); + int (*xSectorSize)(sqlite3_file*); + int (*xDeviceCharacteristics)(sqlite3_file*); + /* Additional methods may be added in future releases */ +}; + +/* +** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> +** +** These integer constants are opcodes for the xFileControl method +** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] +** interface. +** +** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This +** opcode causes the xFileControl method to write the current state of +** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], +** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) +** into an integer that the pArg argument points to. This capability +** is used during testing and only needs to be supported when SQLITE_TEST +** is defined. +*/ +#define SQLITE_FCNTL_LOCKSTATE 1 +#define SQLITE_GET_LOCKPROXYFILE 2 +#define SQLITE_SET_LOCKPROXYFILE 3 +#define SQLITE_LAST_ERRNO 4 + +/* +** CAPI3REF: Mutex Handle {H17110} <S20130> +** +** The mutex module within SQLite defines [sqlite3_mutex] to be an +** abstract type for a mutex object. The SQLite core never looks +** at the internal representation of an [sqlite3_mutex]. It only +** deals with pointers to the [sqlite3_mutex] object. +** +** Mutexes are created using [sqlite3_mutex_alloc()]. +*/ +typedef struct sqlite3_mutex sqlite3_mutex; + +/* +** CAPI3REF: OS Interface Object {H11140} <S20100> +** +** An instance of the sqlite3_vfs object defines the interface between +** the SQLite core and the underlying operating system. The "vfs" +** in the name of the object stands for "virtual file system". +** +** The value of the iVersion field is initially 1 but may be larger in +** future versions of SQLite. Additional fields may be appended to this +** object when the iVersion value is increased. Note that the structure +** of the sqlite3_vfs object changes in the transaction between +** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not +** modified. +** +** The szOsFile field is the size of the subclassed [sqlite3_file] +** structure used by this VFS. mxPathname is the maximum length of +** a pathname in this VFS. +** +** Registered sqlite3_vfs objects are kept on a linked list formed by +** the pNext pointer. The [sqlite3_vfs_register()] +** and [sqlite3_vfs_unregister()] interfaces manage this list +** in a thread-safe way. The [sqlite3_vfs_find()] interface +** searches the list. Neither the application code nor the VFS +** implementation should use the pNext pointer. +** +** The pNext field is the only field in the sqlite3_vfs +** structure that SQLite will ever modify. SQLite will only access +** or modify this field while holding a particular static mutex. +** The application should never modify anything within the sqlite3_vfs +** object once the object has been registered. +** +** The zName field holds the name of the VFS module. The name must +** be unique across all VFS modules. +** +** SQLite will guarantee that the zFilename parameter to xOpen +** is either a NULL pointer or string obtained +** from xFullPathname(). SQLite further guarantees that +** the string will be valid and unchanged until xClose() is +** called. Because of the previous sentence, +** the [sqlite3_file] can safely store a pointer to the +** filename if it needs to remember the filename for some reason. +** If the zFilename parameter is xOpen is a NULL pointer then xOpen +** must invent its own temporary name for the file. Whenever the +** xFilename parameter is NULL it will also be the case that the +** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. +** +** The flags argument to xOpen() includes all bits set in +** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] +** or [sqlite3_open16()] is used, then flags includes at least +** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. +** If xOpen() opens a file read-only then it sets *pOutFlags to +** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. +** +** SQLite will also add one of the following flags to the xOpen() +** call, depending on the object being opened: +** +** <ul> +** <li> [SQLITE_OPEN_MAIN_DB] +** <li> [SQLITE_OPEN_MAIN_JOURNAL] +** <li> [SQLITE_OPEN_TEMP_DB] +** <li> [SQLITE_OPEN_TEMP_JOURNAL] +** <li> [SQLITE_OPEN_TRANSIENT_DB] +** <li> [SQLITE_OPEN_SUBJOURNAL] +** <li> [SQLITE_OPEN_MASTER_JOURNAL] +** </ul> +** +** The file I/O implementation can use the object type flags to +** change the way it deals with files. For example, an application +** that does not care about crash recovery or rollback might make +** the open of a journal file a no-op. Writes to this journal would +** also be no-ops, and any attempt to read the journal would return +** SQLITE_IOERR. Or the implementation might recognize that a database +** file will be doing page-aligned sector reads and writes in a random +** order and set up its I/O subsystem accordingly. +** +** SQLite might also add one of the following flags to the xOpen method: +** +** <ul> +** <li> [SQLITE_OPEN_DELETEONCLOSE] +** <li> [SQLITE_OPEN_EXCLUSIVE] +** </ul> +** +** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be +** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] +** will be set for TEMP databases, journals and for subjournals. +** +** The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction +** with the [SQLITE_OPEN_CREATE] flag, which are both directly +** analogous to the O_EXCL and O_CREAT flags of the POSIX open() +** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the +** SQLITE_OPEN_CREATE, is used to indicate that file should always +** be created, and that it is an error if it already exists. +** It is <i>not</i> used to indicate the file should be opened +** for exclusive access. +** +** At least szOsFile bytes of memory are allocated by SQLite +** to hold the [sqlite3_file] structure passed as the third +** argument to xOpen. The xOpen method does not have to +** allocate the structure; it should just fill it in. Note that +** the xOpen method must set the sqlite3_file.pMethods to either +** a valid [sqlite3_io_methods] object or to NULL. xOpen must do +** this even if the open fails. SQLite expects that the sqlite3_file.pMethods +** element will be valid after xOpen returns regardless of the success +** or failure of the xOpen call. +** +** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] +** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to +** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] +** to test whether a file is at least readable. The file can be a +** directory. +** +** SQLite will always allocate at least mxPathname+1 bytes for the +** output buffer xFullPathname. The exact size of the output buffer +** is also passed as a parameter to both methods. If the output buffer +** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is +** handled as a fatal error by SQLite, vfs implementations should endeavor +** to prevent this by setting mxPathname to a sufficiently large value. +** +** The xRandomness(), xSleep(), and xCurrentTime() interfaces +** are not strictly a part of the filesystem, but they are +** included in the VFS structure for completeness. +** The xRandomness() function attempts to return nBytes bytes +** of good-quality randomness into zOut. The return value is +** the actual number of bytes of randomness obtained. +** The xSleep() method causes the calling thread to sleep for at +** least the number of microseconds given. The xCurrentTime() +** method returns a Julian Day Number for the current date and time. +** +*/ +typedef struct sqlite3_vfs sqlite3_vfs; +struct sqlite3_vfs { + int iVersion; /* Structure version number */ + int szOsFile; /* Size of subclassed sqlite3_file */ + int mxPathname; /* Maximum file pathname length */ + sqlite3_vfs *pNext; /* Next registered VFS */ + const char *zName; /* Name of this virtual file system */ + void *pAppData; /* Pointer to application-specific data */ + int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, + int flags, int *pOutFlags); + int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); + int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); + int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); + void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); + void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); + void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); + void (*xDlClose)(sqlite3_vfs*, void*); + int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); + int (*xSleep)(sqlite3_vfs*, int microseconds); + int (*xCurrentTime)(sqlite3_vfs*, double*); + int (*xGetLastError)(sqlite3_vfs*, int, char *); + /* New fields may be appended in figure versions. The iVersion + ** value will increment whenever this happens. */ +}; + +/* +** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> +** +** These integer constants can be used as the third parameter to +** the xAccess method of an [sqlite3_vfs] object. {END} They determine +** what kind of permissions the xAccess method is looking for. +** With SQLITE_ACCESS_EXISTS, the xAccess method +** simply checks whether the file exists. +** With SQLITE_ACCESS_READWRITE, the xAccess method +** checks whether the file is both readable and writable. +** With SQLITE_ACCESS_READ, the xAccess method +** checks whether the file is readable. +*/ +#define SQLITE_ACCESS_EXISTS 0 +#define SQLITE_ACCESS_READWRITE 1 +#define SQLITE_ACCESS_READ 2 + +/* +** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> +** +** The sqlite3_initialize() routine initializes the +** SQLite library. The sqlite3_shutdown() routine +** deallocates any resources that were allocated by sqlite3_initialize(). +** This routines are designed to aid in process initialization and +** shutdown on embedded systems. Workstation applications using +** SQLite normally do not need to invoke either of these routines. +** +** A call to sqlite3_initialize() is an "effective" call if it is +** the first time sqlite3_initialize() is invoked during the lifetime of +** the process, or if it is the first time sqlite3_initialize() is invoked +** following a call to sqlite3_shutdown(). Only an effective call +** of sqlite3_initialize() does any initialization. All other calls +** are harmless no-ops. +** +** A call to sqlite3_shutdown() is an "effective" call if it is the first +** call to sqlite3_shutdown() since the last sqlite3_initialize(). Only +** an effective call to sqlite3_shutdown() does any deinitialization. +** All other valid calls to sqlite3_shutdown() are harmless no-ops. +** +** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() +** is not. The sqlite3_shutdown() interface must only be called from a +** single thread. All open [database connections] must be closed and all +** other SQLite resources must be deallocated prior to invoking +** sqlite3_shutdown(). +** +** Among other things, sqlite3_initialize() will invoke +** sqlite3_os_init(). Similarly, sqlite3_shutdown() +** will invoke sqlite3_os_end(). +** +** The sqlite3_initialize() routine returns [SQLITE_OK] on success. +** If for some reason, sqlite3_initialize() is unable to initialize +** the library (perhaps it is unable to allocate a needed resource such +** as a mutex) it returns an [error code] other than [SQLITE_OK]. +** +** The sqlite3_initialize() routine is called internally by many other +** SQLite interfaces so that an application usually does not need to +** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] +** calls sqlite3_initialize() so the SQLite library will be automatically +** initialized when [sqlite3_open()] is called if it has not be initialized +** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] +** compile-time option, then the automatic calls to sqlite3_initialize() +** are omitted and the application must call sqlite3_initialize() directly +** prior to using any other SQLite interface. For maximum portability, +** it is recommended that applications always invoke sqlite3_initialize() +** directly prior to using any other SQLite interface. Future releases +** of SQLite may require this. In other words, the behavior exhibited +** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the +** default behavior in some future release of SQLite. +** +** The sqlite3_os_init() routine does operating-system specific +** initialization of the SQLite library. The sqlite3_os_end() +** routine undoes the effect of sqlite3_os_init(). Typical tasks +** performed by these routines include allocation or deallocation +** of static resources, initialization of global variables, +** setting up a default [sqlite3_vfs] module, or setting up +** a default configuration using [sqlite3_config()]. +** +** The application should never invoke either sqlite3_os_init() +** or sqlite3_os_end() directly. The application should only invoke +** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() +** interface is called automatically by sqlite3_initialize() and +** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate +** implementations for sqlite3_os_init() and sqlite3_os_end() +** are built into SQLite when it is compiled for Unix, Windows, or OS/2. +** When [custom builds | built for other platforms] +** (using the [SQLITE_OS_OTHER=1] compile-time +** option) the application must supply a suitable implementation for +** sqlite3_os_init() and sqlite3_os_end(). An application-supplied +** implementation of sqlite3_os_init() or sqlite3_os_end() +** must return [SQLITE_OK] on success and some other [error code] upon +** failure. +*/ +SQLITE_API int sqlite3_initialize(void); +SQLITE_API int sqlite3_shutdown(void); +SQLITE_API int sqlite3_os_init(void); +SQLITE_API int sqlite3_os_end(void); + +/* +** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> +** EXPERIMENTAL +** +** The sqlite3_config() interface is used to make global configuration +** changes to SQLite in order to tune SQLite to the specific needs of +** the application. The default configuration is recommended for most +** applications and so this routine is usually not necessary. It is +** provided to support rare applications with unusual needs. +** +** The sqlite3_config() interface is not threadsafe. The application +** must insure that no other SQLite interfaces are invoked by other +** threads while sqlite3_config() is running. Furthermore, sqlite3_config() +** may only be invoked prior to library initialization using +** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. +** Note, however, that sqlite3_config() can be called as part of the +** implementation of an application-defined [sqlite3_os_init()]. +** +** The first argument to sqlite3_config() is an integer +** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines +** what property of SQLite is to be configured. Subsequent arguments +** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] +** in the first argument. +** +** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. +** If the option is unknown or SQLite is unable to set the option +** then this routine returns a non-zero [error code]. +** +** Requirements: +** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] +** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] +** [H14162] [H14165] [H14168] +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); + +/* +** CAPI3REF: Configure database connections {H14200} <S20000> +** EXPERIMENTAL +** +** The sqlite3_db_config() interface is used to make configuration +** changes to a [database connection]. The interface is similar to +** [sqlite3_config()] except that the changes apply to a single +** [database connection] (specified in the first argument). The +** sqlite3_db_config() interface can only be used immediately after +** the database connection is created using [sqlite3_open()], +** [sqlite3_open16()], or [sqlite3_open_v2()]. +** +** The second argument to sqlite3_db_config(D,V,...) is the +** configuration verb - an integer code that indicates what +** aspect of the [database connection] is being configured. +** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. +** New verbs are likely to be added in future releases of SQLite. +** Additional arguments depend on the verb. +** +** Requirements: +** [H14203] [H14206] [H14209] [H14212] [H14215] +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); + +/* +** CAPI3REF: Memory Allocation Routines {H10155} <S20120> +** EXPERIMENTAL +** +** An instance of this object defines the interface between SQLite +** and low-level memory allocation routines. +** +** This object is used in only one place in the SQLite interface. +** A pointer to an instance of this object is the argument to +** [sqlite3_config()] when the configuration option is +** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. +** By creating an instance of this object +** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) +** during configuration, an application can specify an alternative +** memory allocation subsystem for SQLite to use for all of its +** dynamic memory needs. +** +** Note that SQLite comes with several [built-in memory allocators] +** that are perfectly adequate for the overwhelming majority of applications +** and that this object is only useful to a tiny minority of applications +** with specialized memory allocation requirements. This object is +** also used during testing of SQLite in order to specify an alternative +** memory allocator that simulates memory out-of-memory conditions in +** order to verify that SQLite recovers gracefully from such +** conditions. +** +** The xMalloc and xFree methods must work like the +** malloc() and free() functions from the standard C library. +** The xRealloc method must work like realloc() from the standard C library +** with the exception that if the second argument to xRealloc is zero, +** xRealloc must be a no-op - it must not perform any allocation or +** deallocation. SQLite guaranteeds that the second argument to +** xRealloc is always a value returned by a prior call to xRoundup. +** And so in cases where xRoundup always returns a positive number, +** xRealloc can perform exactly as the standard library realloc() and +** still be in compliance with this specification. +** +** xSize should return the allocated size of a memory allocation +** previously obtained from xMalloc or xRealloc. The allocated size +** is always at least as big as the requested size but may be larger. +** +** The xRoundup method returns what would be the allocated size of +** a memory allocation given a particular requested size. Most memory +** allocators round up memory allocations at least to the next multiple +** of 8. Some allocators round up to a larger multiple or to a power of 2. +** Every memory allocation request coming in through [sqlite3_malloc()] +** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, +** that causes the corresponding memory allocation to fail. +** +** The xInit method initializes the memory allocator. (For example, +** it might allocate any require mutexes or initialize internal data +** structures. The xShutdown method is invoked (indirectly) by +** [sqlite3_shutdown()] and should deallocate any resources acquired +** by xInit. The pAppData pointer is used as the only parameter to +** xInit and xShutdown. +** +** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes +** the xInit method, so the xInit method need not be threadsafe. The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. For all other methods, SQLite +** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the +** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which +** it is by default) and so the methods are automatically serialized. +** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other +** methods must be threadsafe or else make their own arrangements for +** serialization. +** +** SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +*/ +typedef struct sqlite3_mem_methods sqlite3_mem_methods; +struct sqlite3_mem_methods { + void *(*xMalloc)(int); /* Memory allocation function */ + void (*xFree)(void*); /* Free a prior allocation */ + void *(*xRealloc)(void*,int); /* Resize an allocation */ + int (*xSize)(void*); /* Return the size of an allocation */ + int (*xRoundup)(int); /* Round up request size to allocation size */ + int (*xInit)(void*); /* Initialize the memory allocator */ + void (*xShutdown)(void*); /* Deinitialize the memory allocator */ + void *pAppData; /* Argument to xInit() and xShutdown() */ +}; + +/* +** CAPI3REF: Configuration Options {H10160} <S20000> +** EXPERIMENTAL +** +** These constants are the available integer configuration options that +** can be passed as the first argument to the [sqlite3_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_config()] to make sure that +** the call worked. The [sqlite3_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> +** <dd>There are no arguments to this option. This option disables +** all mutexing and puts SQLite into a mode where it can only be used +** by a single thread.</dd> +** +** <dt>SQLITE_CONFIG_MULTITHREAD</dt> +** <dd>There are no arguments to this option. This option disables +** mutexing on [database connection] and [prepared statement] objects. +** The application is responsible for serializing access to +** [database connections] and [prepared statements]. But other mutexes +** are enabled so that SQLite will be safe to use in a multi-threaded +** environment as long as no two threads attempt to use the same +** [database connection] at the same time. See the [threading mode] +** documentation for additional information.</dd> +** +** <dt>SQLITE_CONFIG_SERIALIZED</dt> +** <dd>There are no arguments to this option. This option enables +** all mutexes including the recursive +** mutexes on [database connection] and [prepared statement] objects. +** In this mode (which is the default when SQLite is compiled with +** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access +** to [database connections] and [prepared statements] so that the +** application is free to use the same [database connection] or the +** same [prepared statement] in different threads at the same time. +** See the [threading mode] documentation for additional information.</dd> +** +** <dt>SQLITE_CONFIG_MALLOC</dt> +** <dd>This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mem_methods] structure. The argument specifies +** alternative low-level memory allocation routines to be used in place of +** the memory allocation routines built into SQLite.</dd> +** +** <dt>SQLITE_CONFIG_GETMALLOC</dt> +** <dd>This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] +** structure is filled with the currently defined memory allocation routines. +** This option can be used to overload the default memory allocation +** routines with a wrapper that simulations memory allocation failure or +** tracks memory usage, for example.</dd> +** +** <dt>SQLITE_CONFIG_MEMSTATUS</dt> +** <dd>This option takes single argument of type int, interpreted as a +** boolean, which enables or disables the collection of memory allocation +** statistics. When disabled, the following SQLite interfaces become +** non-operational: +** <ul> +** <li> [sqlite3_memory_used()] +** <li> [sqlite3_memory_highwater()] +** <li> [sqlite3_soft_heap_limit()] +** <li> [sqlite3_status()] +** </ul> +** </dd> +** +** <dt>SQLITE_CONFIG_SCRATCH</dt> +** <dd>This option specifies a static memory buffer that SQLite can use for +** scratch memory. There are three arguments: A pointer an 8-byte +** aligned memory buffer from which the scrach allocations will be +** drawn, the size of each scratch allocation (sz), +** and the maximum number of scratch allocations (N). The sz +** argument must be a multiple of 16. The sz parameter should be a few bytes +** larger than the actual scratch space required due to internal overhead. +** The first argument should pointer to an 8-byte aligned buffer +** of at least sz*N bytes of memory. +** SQLite will use no more than one scratch buffer at once per thread, so +** N should be set to the expected maximum number of threads. The sz +** parameter should be 6 times the size of the largest database page size. +** Scratch buffers are used as part of the btree balance operation. If +** The btree balancer needs additional memory beyond what is provided by +** scratch buffers or if no scratch buffer space is specified, then SQLite +** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> +** +** <dt>SQLITE_CONFIG_PAGECACHE</dt> +** <dd>This option specifies a static memory buffer that SQLite can use for +** the database page cache with the default page cache implemenation. +** This configuration should not be used if an application-define page +** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. +** There are three arguments to this option: A pointer to 8-byte aligned +** memory, the size of each page buffer (sz), and the number of pages (N). +** The sz argument should be the size of the largest database page +** (a power of two between 512 and 32768) plus a little extra for each +** page header. The page header size is 20 to 40 bytes depending on +** the host architecture. It is harmless, apart from the wasted memory, +** to make sz a little too large. The first +** argument should point to an allocation of at least sz*N bytes of memory. +** SQLite will use the memory provided by the first argument to satisfy its +** memory needs for the first N pages that it adds to cache. If additional +** page cache memory is needed beyond what is provided by this option, then +** SQLite goes to [sqlite3_malloc()] for the additional storage space. +** The implementation might use one or more of the N buffers to hold +** memory accounting information. The pointer in the first argument must +** be aligned to an 8-byte boundary or subsequent behavior of SQLite +** will be undefined.</dd> +** +** <dt>SQLITE_CONFIG_HEAP</dt> +** <dd>This option specifies a static memory buffer that SQLite will use +** for all of its dynamic memory allocation needs beyond those provided +** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. +** There are three arguments: An 8-byte aligned pointer to the memory, +** the number of bytes in the memory buffer, and the minimum allocation size. +** If the first pointer (the memory pointer) is NULL, then SQLite reverts +** to using its default memory allocator (the system malloc() implementation), +** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the +** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or +** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory +** allocator is engaged to handle all of SQLites memory allocation needs. +** The first pointer (the memory pointer) must be aligned to an 8-byte +** boundary or subsequent behavior of SQLite will be undefined.</dd> +** +** <dt>SQLITE_CONFIG_MUTEX</dt> +** <dd>This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mutex_methods] structure. The argument specifies +** alternative low-level mutex routines to be used in place +** the mutex routines built into SQLite.</dd> +** +** <dt>SQLITE_CONFIG_GETMUTEX</dt> +** <dd>This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mutex_methods] structure. The +** [sqlite3_mutex_methods] +** structure is filled with the currently defined mutex routines. +** This option can be used to overload the default mutex allocation +** routines with a wrapper used to track mutex usage for performance +** profiling or testing, for example.</dd> +** +** <dt>SQLITE_CONFIG_LOOKASIDE</dt> +** <dd>This option takes two arguments that determine the default +** memory allocation lookaside optimization. The first argument is the +** size of each lookaside buffer slot and the second is the number of +** slots allocated to each database connection. This option sets the +** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] +** verb to [sqlite3_db_config()] can be used to change the lookaside +** configuration on individual connections.</dd> +** +** <dt>SQLITE_CONFIG_PCACHE</dt> +** <dd>This option takes a single argument which is a pointer to +** an [sqlite3_pcache_methods] object. This object specifies the interface +** to a custom page cache implementation. SQLite makes a copy of the +** object and uses it for page cache memory allocations.</dd> +** +** <dt>SQLITE_CONFIG_GETPCACHE</dt> +** <dd>This option takes a single argument which is a pointer to an +** [sqlite3_pcache_methods] object. SQLite copies of the current +** page cache implementation into that object.</dd> +** +** </dl> +*/ +#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ +#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ +#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ +#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ +#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ +#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ +#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ +#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ +#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ +/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ +#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ +#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ +#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ + +/* +** CAPI3REF: Configuration Options {H10170} <S20000> +** EXPERIMENTAL +** +** These constants are the available integer configuration options that +** can be passed as the second argument to the [sqlite3_db_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_db_config()] to make sure that +** the call worked. The [sqlite3_db_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> +** <dd>This option takes three additional arguments that determine the +** [lookaside memory allocator] configuration for the [database connection]. +** The first argument (the third parameter to [sqlite3_db_config()] is a +** pointer to an memory buffer to use for lookaside memory. +** The first argument may be NULL in which case SQLite will allocate the +** lookaside buffer itself using [sqlite3_malloc()]. The second argument is the +** size of each lookaside buffer slot and the third argument is the number of +** slots. The size of the buffer in the first argument must be greater than +** or equal to the product of the second and third arguments. The buffer +** must be aligned to an 8-byte boundary. If the second argument is not +** a multiple of 8, it is internally rounded down to the next smaller +** multiple of 8. See also: [SQLITE_CONFIG_LOOKASIDE]</dd> +** +** </dl> +*/ +#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ + + +/* +** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> +** +** The sqlite3_extended_result_codes() routine enables or disables the +** [extended result codes] feature of SQLite. The extended result +** codes are disabled by default for historical compatibility considerations. +** +** Requirements: +** [H12201] [H12202] +*/ +SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); + +/* +** CAPI3REF: Last Insert Rowid {H12220} <S10700> +** +** Each entry in an SQLite table has a unique 64-bit signed +** integer key called the [ROWID | "rowid"]. The rowid is always available +** as an undeclared column named ROWID, OID, or _ROWID_ as long as those +** names are not also used by explicitly declared columns. If +** the table has a column of type [INTEGER PRIMARY KEY] then that column +** is another alias for the rowid. +** +** This routine returns the [rowid] of the most recent +** successful [INSERT] into the database from the [database connection] +** in the first argument. If no successful [INSERT]s +** have ever occurred on that database connection, zero is returned. +** +** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted +** row is returned by this routine as long as the trigger is running. +** But once the trigger terminates, the value returned by this routine +** reverts to the last value inserted before the trigger fired. +** +** An [INSERT] that fails due to a constraint violation is not a +** successful [INSERT] and does not change the value returned by this +** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, +** and INSERT OR ABORT make no changes to the return value of this +** routine when their insertion fails. When INSERT OR REPLACE +** encounters a constraint violation, it does not fail. The +** INSERT continues to completion after deleting rows that caused +** the constraint problem so INSERT OR REPLACE will always change +** the return value of this interface. +** +** For the purposes of this routine, an [INSERT] is considered to +** be successful even if it is subsequently rolled back. +** +** Requirements: +** [H12221] [H12223] +** +** If a separate thread performs a new [INSERT] on the same +** database connection while the [sqlite3_last_insert_rowid()] +** function is running and thus changes the last insert [rowid], +** then the value returned by [sqlite3_last_insert_rowid()] is +** unpredictable and might not equal either the old or the new +** last insert [rowid]. +*/ +SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); + +/* +** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> +** +** This function returns the number of database rows that were changed +** or inserted or deleted by the most recently completed SQL statement +** on the [database connection] specified by the first parameter. +** Only changes that are directly specified by the [INSERT], [UPDATE], +** or [DELETE] statement are counted. Auxiliary changes caused by +** triggers or [foreign key actions] are not counted. Use the +** [sqlite3_total_changes()] function to find the total number of changes +** including changes caused by triggers and foreign key actions. +** +** Changes to a view that are simulated by an [INSTEAD OF trigger] +** are not counted. Only real table changes are counted. +** +** A "row change" is a change to a single row of a single table +** caused by an INSERT, DELETE, or UPDATE statement. Rows that +** are changed as side effects of [REPLACE] constraint resolution, +** rollback, ABORT processing, [DROP TABLE], or by any other +** mechanisms do not count as direct row changes. +** +** A "trigger context" is a scope of execution that begins and +** ends with the script of a [CREATE TRIGGER | trigger]. +** Most SQL statements are +** evaluated outside of any trigger. This is the "top level" +** trigger context. If a trigger fires from the top level, a +** new trigger context is entered for the duration of that one +** trigger. Subtriggers create subcontexts for their duration. +** +** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does +** not create a new trigger context. +** +** This function returns the number of direct row changes in the +** most recent INSERT, UPDATE, or DELETE statement within the same +** trigger context. +** +** Thus, when called from the top level, this function returns the +** number of changes in the most recent INSERT, UPDATE, or DELETE +** that also occurred at the top level. Within the body of a trigger, +** the sqlite3_changes() interface can be called to find the number of +** changes in the most recently completed INSERT, UPDATE, or DELETE +** statement within the body of the same trigger. +** However, the number returned does not include changes +** caused by subtriggers since those have their own context. +** +** See also the [sqlite3_total_changes()] interface and the +** [count_changes pragma]. +** +** Requirements: +** [H12241] [H12243] +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_changes()] is running then the value returned +** is unpredictable and not meaningful. +*/ +SQLITE_API int sqlite3_changes(sqlite3*); + +/* +** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> +** +** This function returns the number of row changes caused by [INSERT], +** [UPDATE] or [DELETE] statements since the [database connection] was opened. +** The count includes all changes from all [CREATE TRIGGER | trigger] +** contexts and changes made by [foreign key actions]. However, +** the count does not include changes used to implement [REPLACE] constraints, +** do rollbacks or ABORT processing, or [DROP TABLE] processing. The +** count does not include rows of views that fire an [INSTEAD OF trigger], +** though if the INSTEAD OF trigger makes changes of its own, those changes +** are counted. +** The changes are counted as soon as the statement that makes them is +** completed (when the statement handle is passed to [sqlite3_reset()] or +** [sqlite3_finalize()]). +** +** See also the [sqlite3_changes()] interface and the +** [count_changes pragma]. +** +** Requirements: +** [H12261] [H12263] +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_total_changes()] is running then the value +** returned is unpredictable and not meaningful. +*/ +SQLITE_API int sqlite3_total_changes(sqlite3*); + +/* +** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> +** +** This function causes any pending database operation to abort and +** return at its earliest opportunity. This routine is typically +** called in response to a user action such as pressing "Cancel" +** or Ctrl-C where the user wants a long query operation to halt +** immediately. +** +** It is safe to call this routine from a thread different from the +** thread that is currently running the database operation. But it +** is not safe to call this routine with a [database connection] that +** is closed or might close before sqlite3_interrupt() returns. +** +** If an SQL operation is very nearly finished at the time when +** sqlite3_interrupt() is called, then it might not have an opportunity +** to be interrupted and might continue to completion. +** +** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. +** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE +** that is inside an explicit transaction, then the entire transaction +** will be rolled back automatically. +** +** The sqlite3_interrupt(D) call is in effect until all currently running +** SQL statements on [database connection] D complete. Any new SQL statements +** that are started after the sqlite3_interrupt() call and before the +** running statements reaches zero are interrupted as if they had been +** running prior to the sqlite3_interrupt() call. New SQL statements +** that are started after the running statement count reaches zero are +** not effected by the sqlite3_interrupt(). +** A call to sqlite3_interrupt(D) that occurs when there are no running +** SQL statements is a no-op and has no effect on SQL statements +** that are started after the sqlite3_interrupt() call returns. +** +** Requirements: +** [H12271] [H12272] +** +** If the database connection closes while [sqlite3_interrupt()] +** is running then bad things will likely happen. +*/ +SQLITE_API void sqlite3_interrupt(sqlite3*); + +/* +** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> +** +** These routines are useful during command-line input to determine if the +** currently entered text seems to form a complete SQL statement or +** if additional input is needed before sending the text into +** SQLite for parsing. These routines return 1 if the input string +** appears to be a complete SQL statement. A statement is judged to be +** complete if it ends with a semicolon token and is not a prefix of a +** well-formed CREATE TRIGGER statement. Semicolons that are embedded within +** string literals or quoted identifier names or comments are not +** independent tokens (they are part of the token in which they are +** embedded) and thus do not count as a statement terminator. Whitespace +** and comments that follow the final semicolon are ignored. +** +** These routines return 0 if the statement is incomplete. If a +** memory allocation fails, then SQLITE_NOMEM is returned. +** +** These routines do not parse the SQL statements thus +** will not detect syntactically incorrect SQL. +** +** If SQLite has not been initialized using [sqlite3_initialize()] prior +** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked +** automatically by sqlite3_complete16(). If that initialization fails, +** then the return value from sqlite3_complete16() will be non-zero +** regardless of whether or not the input SQL is complete. +** +** Requirements: [H10511] [H10512] +** +** The input to [sqlite3_complete()] must be a zero-terminated +** UTF-8 string. +** +** The input to [sqlite3_complete16()] must be a zero-terminated +** UTF-16 string in native byte order. +*/ +SQLITE_API int sqlite3_complete(const char *sql); +SQLITE_API int sqlite3_complete16(const void *sql); + +/* +** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> +** +** This routine sets a callback function that might be invoked whenever +** an attempt is made to open a database table that another thread +** or process has locked. +** +** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] +** is returned immediately upon encountering the lock. If the busy callback +** is not NULL, then the callback will be invoked with two arguments. +** +** The first argument to the handler is a copy of the void* pointer which +** is the third argument to sqlite3_busy_handler(). The second argument to +** the handler callback is the number of times that the busy handler has +** been invoked for this locking event. If the +** busy callback returns 0, then no additional attempts are made to +** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. +** If the callback returns non-zero, then another attempt +** is made to open the database for reading and the cycle repeats. +** +** The presence of a busy handler does not guarantee that it will be invoked +** when there is lock contention. If SQLite determines that invoking the busy +** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] +** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. +** Consider a scenario where one process is holding a read lock that +** it is trying to promote to a reserved lock and +** a second process is holding a reserved lock that it is trying +** to promote to an exclusive lock. The first process cannot proceed +** because it is blocked by the second and the second process cannot +** proceed because it is blocked by the first. If both processes +** invoke the busy handlers, neither will make any progress. Therefore, +** SQLite returns [SQLITE_BUSY] for the first process, hoping that this +** will induce the first process to release its read lock and allow +** the second process to proceed. +** +** The default busy callback is NULL. +** +** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] +** when SQLite is in the middle of a large transaction where all the +** changes will not fit into the in-memory cache. SQLite will +** already hold a RESERVED lock on the database file, but it needs +** to promote this lock to EXCLUSIVE so that it can spill cache +** pages into the database file without harm to concurrent +** readers. If it is unable to promote the lock, then the in-memory +** cache will be left in an inconsistent state and so the error +** code is promoted from the relatively benign [SQLITE_BUSY] to +** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion +** forces an automatic rollback of the changes. See the +** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> +** CorruptionFollowingBusyError</a> wiki page for a discussion of why +** this is important. +** +** There can only be a single busy handler defined for each +** [database connection]. Setting a new busy handler clears any +** previously set handler. Note that calling [sqlite3_busy_timeout()] +** will also set or clear the busy handler. +** +** The busy callback should not take any actions which modify the +** database connection that invoked the busy handler. Any such actions +** result in undefined behavior. +** +** Requirements: +** [H12311] [H12312] [H12314] [H12316] [H12318] +** +** A busy handler must not close the database connection +** or [prepared statement] that invoked the busy handler. +*/ +SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); + +/* +** CAPI3REF: Set A Busy Timeout {H12340} <S40410> +** +** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps +** for a specified amount of time when a table is locked. The handler +** will sleep multiple times until at least "ms" milliseconds of sleeping +** have accumulated. {H12343} After "ms" milliseconds of sleeping, +** the handler returns 0 which causes [sqlite3_step()] to return +** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. +** +** Calling this routine with an argument less than or equal to zero +** turns off all busy handlers. +** +** There can only be a single busy handler for a particular +** [database connection] any any given moment. If another busy handler +** was defined (using [sqlite3_busy_handler()]) prior to calling +** this routine, that other busy handler is cleared. +** +** Requirements: +** [H12341] [H12343] [H12344] +*/ +SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); + +/* +** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> +** +** Definition: A <b>result table</b> is memory data structure created by the +** [sqlite3_get_table()] interface. A result table records the +** complete query results from one or more queries. +** +** The table conceptually has a number of rows and columns. But +** these numbers are not part of the result table itself. These +** numbers are obtained separately. Let N be the number of rows +** and M be the number of columns. +** +** A result table is an array of pointers to zero-terminated UTF-8 strings. +** There are (N+1)*M elements in the array. The first M pointers point +** to zero-terminated strings that contain the names of the columns. +** The remaining entries all point to query results. NULL values result +** in NULL pointers. All other values are in their UTF-8 zero-terminated +** string representation as returned by [sqlite3_column_text()]. +** +** A result table might consist of one or more memory allocations. +** It is not safe to pass a result table directly to [sqlite3_free()]. +** A result table should be deallocated using [sqlite3_free_table()]. +** +** As an example of the result table format, suppose a query result +** is as follows: +** +** <blockquote><pre> +** Name | Age +** ----------------------- +** Alice | 43 +** Bob | 28 +** Cindy | 21 +** </pre></blockquote> +** +** There are two column (M==2) and three rows (N==3). Thus the +** result table has 8 entries. Suppose the result table is stored +** in an array names azResult. Then azResult holds this content: +** +** <blockquote><pre> +** azResult[0] = "Name"; +** azResult[1] = "Age"; +** azResult[2] = "Alice"; +** azResult[3] = "43"; +** azResult[4] = "Bob"; +** azResult[5] = "28"; +** azResult[6] = "Cindy"; +** azResult[7] = "21"; +** </pre></blockquote> +** +** The sqlite3_get_table() function evaluates one or more +** semicolon-separated SQL statements in the zero-terminated UTF-8 +** string of its 2nd parameter. It returns a result table to the +** pointer given in its 3rd parameter. +** +** After the calling function has finished using the result, it should +** pass the pointer to the result table to sqlite3_free_table() in order to +** release the memory that was malloced. Because of the way the +** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling +** function must not try to call [sqlite3_free()] directly. Only +** [sqlite3_free_table()] is able to release the memory properly and safely. +** +** The sqlite3_get_table() interface is implemented as a wrapper around +** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access +** to any internal data structures of SQLite. It uses only the public +** interface defined here. As a consequence, errors that occur in the +** wrapper layer outside of the internal [sqlite3_exec()] call are not +** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. +** +** Requirements: +** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] +*/ +SQLITE_API int sqlite3_get_table( + sqlite3 *db, /* An open database */ + const char *zSql, /* SQL to be evaluated */ + char ***pazResult, /* Results of the query */ + int *pnRow, /* Number of result rows written here */ + int *pnColumn, /* Number of result columns written here */ + char **pzErrmsg /* Error msg written here */ +); +SQLITE_API void sqlite3_free_table(char **result); + +/* +** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> +** +** These routines are work-alikes of the "printf()" family of functions +** from the standard C library. +** +** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their +** results into memory obtained from [sqlite3_malloc()]. +** The strings returned by these two routines should be +** released by [sqlite3_free()]. Both routines return a +** NULL pointer if [sqlite3_malloc()] is unable to allocate enough +** memory to hold the resulting string. +** +** In sqlite3_snprintf() routine is similar to "snprintf()" from +** the standard C library. The result is written into the +** buffer supplied as the second parameter whose size is given by +** the first parameter. Note that the order of the +** first two parameters is reversed from snprintf(). This is an +** historical accident that cannot be fixed without breaking +** backwards compatibility. Note also that sqlite3_snprintf() +** returns a pointer to its buffer instead of the number of +** characters actually written into the buffer. We admit that +** the number of characters written would be a more useful return +** value but we cannot change the implementation of sqlite3_snprintf() +** now without breaking compatibility. +** +** As long as the buffer size is greater than zero, sqlite3_snprintf() +** guarantees that the buffer is always zero-terminated. The first +** parameter "n" is the total size of the buffer, including space for +** the zero terminator. So the longest string that can be completely +** written will be n-1 characters. +** +** These routines all implement some additional formatting +** options that are useful for constructing SQL statements. +** All of the usual printf() formatting options apply. In addition, there +** is are "%q", "%Q", and "%z" options. +** +** The %q option works like %s in that it substitutes a null-terminated +** string from the argument list. But %q also doubles every '\'' character. +** %q is designed for use inside a string literal. By doubling each '\'' +** character it escapes that character and allows it to be inserted into +** the string. +** +** For example, assume the string variable zText contains text as follows: +** +** <blockquote><pre> +** char *zText = "It's a happy day!"; +** </pre></blockquote> +** +** One can use this text in an SQL statement as follows: +** +** <blockquote><pre> +** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); +** sqlite3_exec(db, zSQL, 0, 0, 0); +** sqlite3_free(zSQL); +** </pre></blockquote> +** +** Because the %q format string is used, the '\'' character in zText +** is escaped and the SQL generated is as follows: +** +** <blockquote><pre> +** INSERT INTO table1 VALUES('It''s a happy day!') +** </pre></blockquote> +** +** This is correct. Had we used %s instead of %q, the generated SQL +** would have looked like this: +** +** <blockquote><pre> +** INSERT INTO table1 VALUES('It's a happy day!'); +** </pre></blockquote> +** +** This second example is an SQL syntax error. As a general rule you should +** always use %q instead of %s when inserting text into a string literal. +** +** The %Q option works like %q except it also adds single quotes around +** the outside of the total string. Additionally, if the parameter in the +** argument list is a NULL pointer, %Q substitutes the text "NULL" (without +** single quotes) in place of the %Q option. So, for example, one could say: +** +** <blockquote><pre> +** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); +** sqlite3_exec(db, zSQL, 0, 0, 0); +** sqlite3_free(zSQL); +** </pre></blockquote> +** +** The code above will render a correct SQL statement in the zSQL +** variable even if the zText variable is a NULL pointer. +** +** The "%z" formatting option works exactly like "%s" with the +** addition that after the string has been read and copied into +** the result, [sqlite3_free()] is called on the input string. {END} +** +** Requirements: +** [H17403] [H17406] [H17407] +*/ +SQLITE_API char *sqlite3_mprintf(const char*,...); +SQLITE_API char *sqlite3_vmprintf(const char*, va_list); +SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); + +/* +** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> +** +** The SQLite core uses these three routines for all of its own +** internal memory allocation needs. "Core" in the previous sentence +** does not include operating-system specific VFS implementation. The +** Windows VFS uses native malloc() and free() for some operations. +** +** The sqlite3_malloc() routine returns a pointer to a block +** of memory at least N bytes in length, where N is the parameter. +** If sqlite3_malloc() is unable to obtain sufficient free +** memory, it returns a NULL pointer. If the parameter N to +** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns +** a NULL pointer. +** +** Calling sqlite3_free() with a pointer previously returned +** by sqlite3_malloc() or sqlite3_realloc() releases that memory so +** that it might be reused. The sqlite3_free() routine is +** a no-op if is called with a NULL pointer. Passing a NULL pointer +** to sqlite3_free() is harmless. After being freed, memory +** should neither be read nor written. Even reading previously freed +** memory might result in a segmentation fault or other severe error. +** Memory corruption, a segmentation fault, or other severe error +** might result if sqlite3_free() is called with a non-NULL pointer that +** was not obtained from sqlite3_malloc() or sqlite3_realloc(). +** +** The sqlite3_realloc() interface attempts to resize a +** prior memory allocation to be at least N bytes, where N is the +** second parameter. The memory allocation to be resized is the first +** parameter. If the first parameter to sqlite3_realloc() +** is a NULL pointer then its behavior is identical to calling +** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). +** If the second parameter to sqlite3_realloc() is zero or +** negative then the behavior is exactly the same as calling +** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). +** sqlite3_realloc() returns a pointer to a memory allocation +** of at least N bytes in size or NULL if sufficient memory is unavailable. +** If M is the size of the prior allocation, then min(N,M) bytes +** of the prior allocation are copied into the beginning of buffer returned +** by sqlite3_realloc() and the prior allocation is freed. +** If sqlite3_realloc() returns NULL, then the prior allocation +** is not freed. +** +** The memory returned by sqlite3_malloc() and sqlite3_realloc() +** is always aligned to at least an 8 byte boundary. {END} +** +** The default implementation of the memory allocation subsystem uses +** the malloc(), realloc() and free() provided by the standard C library. +** {H17382} However, if SQLite is compiled with the +** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> +** is an integer), then SQLite create a static array of at least +** <i>NNN</i> bytes in size and uses that array for all of its dynamic +** memory allocation needs. {END} Additional memory allocator options +** may be added in future releases. +** +** In SQLite version 3.5.0 and 3.5.1, it was possible to define +** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in +** implementation of these routines to be omitted. That capability +** is no longer provided. Only built-in memory allocators can be used. +** +** The Windows OS interface layer calls +** the system malloc() and free() directly when converting +** filenames between the UTF-8 encoding used by SQLite +** and whatever filename encoding is used by the particular Windows +** installation. Memory allocation errors are detected, but +** they are reported back as [SQLITE_CANTOPEN] or +** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. +** +** Requirements: +** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] +** [H17321] [H17322] [H17323] +** +** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] +** must be either NULL or else pointers obtained from a prior +** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have +** not yet been released. +** +** The application must not read or write any part of +** a block of memory after it has been released using +** [sqlite3_free()] or [sqlite3_realloc()]. +*/ +SQLITE_API void *sqlite3_malloc(int); +SQLITE_API void *sqlite3_realloc(void*, int); +SQLITE_API void sqlite3_free(void*); + +/* +** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> +** +** SQLite provides these two interfaces for reporting on the status +** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] +** routines, which form the built-in memory allocation subsystem. +** +** Requirements: +** [H17371] [H17373] [H17374] [H17375] +*/ +SQLITE_API sqlite3_int64 sqlite3_memory_used(void); +SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); + +/* +** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> +** +** SQLite contains a high-quality pseudo-random number generator (PRNG) used to +** select random [ROWID | ROWIDs] when inserting new records into a table that +** already uses the largest possible [ROWID]. The PRNG is also used for +** the build-in random() and randomblob() SQL functions. This interface allows +** applications to access the same PRNG for other purposes. +** +** A call to this routine stores N bytes of randomness into buffer P. +** +** The first time this routine is invoked (either internally or by +** the application) the PRNG is seeded using randomness obtained +** from the xRandomness method of the default [sqlite3_vfs] object. +** On all subsequent invocations, the pseudo-randomness is generated +** internally and without recourse to the [sqlite3_vfs] xRandomness +** method. +** +** Requirements: +** [H17392] +*/ +SQLITE_API void sqlite3_randomness(int N, void *P); + +/* +** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> +** +** This routine registers a authorizer callback with a particular +** [database connection], supplied in the first argument. +** The authorizer callback is invoked as SQL statements are being compiled +** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], +** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various +** points during the compilation process, as logic is being created +** to perform various actions, the authorizer callback is invoked to +** see if those actions are allowed. The authorizer callback should +** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the +** specific action but allow the SQL statement to continue to be +** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be +** rejected with an error. If the authorizer callback returns +** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] +** then the [sqlite3_prepare_v2()] or equivalent call that triggered +** the authorizer will fail with an error message. +** +** When the callback returns [SQLITE_OK], that means the operation +** requested is ok. When the callback returns [SQLITE_DENY], the +** [sqlite3_prepare_v2()] or equivalent call that triggered the +** authorizer will fail with an error message explaining that +** access is denied. +** +** The first parameter to the authorizer callback is a copy of the third +** parameter to the sqlite3_set_authorizer() interface. The second parameter +** to the callback is an integer [SQLITE_COPY | action code] that specifies +** the particular action to be authorized. The third through sixth parameters +** to the callback are zero-terminated strings that contain additional +** details about the action to be authorized. +** +** If the action code is [SQLITE_READ] +** and the callback returns [SQLITE_IGNORE] then the +** [prepared statement] statement is constructed to substitute +** a NULL value in place of the table column that would have +** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] +** return can be used to deny an untrusted user access to individual +** columns of a table. +** If the action code is [SQLITE_DELETE] and the callback returns +** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the +** [truncate optimization] is disabled and all rows are deleted individually. +** +** An authorizer is used when [sqlite3_prepare | preparing] +** SQL statements from an untrusted source, to ensure that the SQL statements +** do not try to access data they are not allowed to see, or that they do not +** try to execute malicious statements that damage the database. For +** example, an application may allow a user to enter arbitrary +** SQL queries for evaluation by a database. But the application does +** not want the user to be able to make arbitrary changes to the +** database. An authorizer could then be put in place while the +** user-entered SQL is being [sqlite3_prepare | prepared] that +** disallows everything except [SELECT] statements. +** +** Applications that need to process SQL from untrusted sources +** might also consider lowering resource limits using [sqlite3_limit()] +** and limiting database size using the [max_page_count] [PRAGMA] +** in addition to using an authorizer. +** +** Only a single authorizer can be in place on a database connection +** at a time. Each call to sqlite3_set_authorizer overrides the +** previous call. Disable the authorizer by installing a NULL callback. +** The authorizer is disabled by default. +** +** The authorizer callback must not do anything that will modify +** the database connection that invoked the authorizer callback. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** When [sqlite3_prepare_v2()] is used to prepare a statement, the +** statement might be re-prepared during [sqlite3_step()] due to a +** schema change. Hence, the application should ensure that the +** correct authorizer callback remains in place during the [sqlite3_step()]. +** +** Note that the authorizer callback is invoked only during +** [sqlite3_prepare()] or its variants. Authorization is not +** performed during statement evaluation in [sqlite3_step()], unless +** as stated in the previous paragraph, sqlite3_step() invokes +** sqlite3_prepare_v2() to reprepare a statement after a schema change. +** +** Requirements: +** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] +** [H12511] [H12512] [H12520] [H12521] [H12522] +*/ +SQLITE_API int sqlite3_set_authorizer( + sqlite3*, + int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), + void *pUserData +); + +/* +** CAPI3REF: Authorizer Return Codes {H12590} <H12500> +** +** The [sqlite3_set_authorizer | authorizer callback function] must +** return either [SQLITE_OK] or one of these two constants in order +** to signal SQLite whether or not the action is permitted. See the +** [sqlite3_set_authorizer | authorizer documentation] for additional +** information. +*/ +#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ +#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ + +/* +** CAPI3REF: Authorizer Action Codes {H12550} <H12500> +** +** The [sqlite3_set_authorizer()] interface registers a callback function +** that is invoked to authorize certain SQL statement actions. The +** second parameter to the callback is an integer code that specifies +** what action is being authorized. These are the integer action codes that +** the authorizer callback may be passed. +** +** These action code values signify what kind of operation is to be +** authorized. The 3rd and 4th parameters to the authorization +** callback function will be parameters or NULL depending on which of these +** codes is used as the second parameter. The 5th parameter to the +** authorizer callback is the name of the database ("main", "temp", +** etc.) if applicable. The 6th parameter to the authorizer callback +** is the name of the inner-most trigger or view that is responsible for +** the access attempt or NULL if this access attempt is directly from +** top-level SQL code. +** +** Requirements: +** [H12551] [H12552] [H12553] [H12554] +*/ +/******************************************* 3rd ************ 4th ***********/ +#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ +#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ +#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ +#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ +#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ +#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ +#define SQLITE_DELETE 9 /* Table Name NULL */ +#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ +#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ +#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ +#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ +#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ +#define SQLITE_DROP_VIEW 17 /* View Name NULL */ +#define SQLITE_INSERT 18 /* Table Name NULL */ +#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ +#define SQLITE_READ 20 /* Table Name Column Name */ +#define SQLITE_SELECT 21 /* NULL NULL */ +#define SQLITE_TRANSACTION 22 /* Operation NULL */ +#define SQLITE_UPDATE 23 /* Table Name Column Name */ +#define SQLITE_ATTACH 24 /* Filename NULL */ +#define SQLITE_DETACH 25 /* Database Name NULL */ +#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ +#define SQLITE_REINDEX 27 /* Index Name NULL */ +#define SQLITE_ANALYZE 28 /* Table Name NULL */ +#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ +#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ +#define SQLITE_FUNCTION 31 /* NULL Function Name */ +#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ +#define SQLITE_COPY 0 /* No longer used */ + +/* +** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> +** EXPERIMENTAL +** +** These routines register callback functions that can be used for +** tracing and profiling the execution of SQL statements. +** +** The callback function registered by sqlite3_trace() is invoked at +** various times when an SQL statement is being run by [sqlite3_step()]. +** The callback returns a UTF-8 rendering of the SQL statement text +** as the statement first begins executing. Additional callbacks occur +** as each triggered subprogram is entered. The callbacks for triggers +** contain a UTF-8 SQL comment that identifies the trigger. +** +** The callback function registered by sqlite3_profile() is invoked +** as each SQL statement finishes. The profile callback contains +** the original statement text and an estimate of wall-clock time +** of how long that statement took to run. +** +** Requirements: +** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] +** [H12290] +*/ +SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); +SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, + void(*xProfile)(void*,const char*,sqlite3_uint64), void*); + +/* +** CAPI3REF: Query Progress Callbacks {H12910} <S60400> +** +** This routine configures a callback function - the +** progress callback - that is invoked periodically during long +** running calls to [sqlite3_exec()], [sqlite3_step()] and +** [sqlite3_get_table()]. An example use for this +** interface is to keep a GUI updated during a large query. +** +** If the progress callback returns non-zero, the operation is +** interrupted. This feature can be used to implement a +** "Cancel" button on a GUI progress dialog box. +** +** The progress handler must not do anything that will modify +** the database connection that invoked the progress handler. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** Requirements: +** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] +** +*/ +SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); + +/* +** CAPI3REF: Opening A New Database Connection {H12700} <S40200> +** +** These routines open an SQLite database file whose name is given by the +** filename argument. The filename argument is interpreted as UTF-8 for +** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte +** order for sqlite3_open16(). A [database connection] handle is usually +** returned in *ppDb, even if an error occurs. The only exception is that +** if SQLite is unable to allocate memory to hold the [sqlite3] object, +** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] +** object. If the database is opened (and/or created) successfully, then +** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The +** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain +** an English language description of the error. +** +** The default encoding for the database will be UTF-8 if +** sqlite3_open() or sqlite3_open_v2() is called and +** UTF-16 in the native byte order if sqlite3_open16() is used. +** +** Whether or not an error occurs when it is opened, resources +** associated with the [database connection] handle should be released by +** passing it to [sqlite3_close()] when it is no longer required. +** +** The sqlite3_open_v2() interface works like sqlite3_open() +** except that it accepts two additional parameters for additional control +** over the new database connection. The flags parameter can take one of +** the following three values, optionally combined with the +** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], +** and/or [SQLITE_OPEN_PRIVATECACHE] flags: +** +** <dl> +** <dt>[SQLITE_OPEN_READONLY]</dt> +** <dd>The database is opened in read-only mode. If the database does not +** already exist, an error is returned.</dd> +** +** <dt>[SQLITE_OPEN_READWRITE]</dt> +** <dd>The database is opened for reading and writing if possible, or reading +** only if the file is write protected by the operating system. In either +** case the database must already exist, otherwise an error is returned.</dd> +** +** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> +** <dd>The database is opened for reading and writing, and is creates it if +** it does not already exist. This is the behavior that is always used for +** sqlite3_open() and sqlite3_open16().</dd> +** </dl> +** +** If the 3rd parameter to sqlite3_open_v2() is not one of the +** combinations shown above or one of the combinations shown above combined +** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], +** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_SHAREDCACHE] flags, +** then the behavior is undefined. +** +** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection +** opens in the multi-thread [threading mode] as long as the single-thread +** mode has not been set at compile-time or start-time. If the +** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens +** in the serialized [threading mode] unless single-thread was +** previously selected at compile-time or start-time. +** The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be +** eligible to use [shared cache mode], regardless of whether or not shared +** cache is enabled using [sqlite3_enable_shared_cache()]. The +** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not +** participate in [shared cache mode] even if it is enabled. +** +** If the filename is ":memory:", then a private, temporary in-memory database +** is created for the connection. This in-memory database will vanish when +** the database connection is closed. Future versions of SQLite might +** make use of additional special filenames that begin with the ":" character. +** It is recommended that when a database filename actually does begin with +** a ":" character you should prefix the filename with a pathname such as +** "./" to avoid ambiguity. +** +** If the filename is an empty string, then a private, temporary +** on-disk database will be created. This private database will be +** automatically deleted as soon as the database connection is closed. +** +** The fourth parameter to sqlite3_open_v2() is the name of the +** [sqlite3_vfs] object that defines the operating system interface that +** the new database connection should use. If the fourth parameter is +** a NULL pointer then the default [sqlite3_vfs] object is used. +** +** <b>Note to Windows users:</b> The encoding used for the filename argument +** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever +** codepage is currently defined. Filenames containing international +** characters must be converted to UTF-8 prior to passing them into +** sqlite3_open() or sqlite3_open_v2(). +** +** Requirements: +** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] +** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] +*/ +SQLITE_API int sqlite3_open( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +SQLITE_API int sqlite3_open16( + const void *filename, /* Database filename (UTF-16) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +SQLITE_API int sqlite3_open_v2( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb, /* OUT: SQLite db handle */ + int flags, /* Flags */ + const char *zVfs /* Name of VFS module to use */ +); + +/* +** CAPI3REF: Error Codes And Messages {H12800} <S60200> +** +** The sqlite3_errcode() interface returns the numeric [result code] or +** [extended result code] for the most recent failed sqlite3_* API call +** associated with a [database connection]. If a prior API call failed +** but the most recent API call succeeded, the return value from +** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() +** interface is the same except that it always returns the +** [extended result code] even when extended result codes are +** disabled. +** +** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language +** text that describes the error, as either UTF-8 or UTF-16 respectively. +** Memory to hold the error message string is managed internally. +** The application does not need to worry about freeing the result. +** However, the error string might be overwritten or deallocated by +** subsequent calls to other SQLite interface functions. +** +** When the serialized [threading mode] is in use, it might be the +** case that a second error occurs on a separate thread in between +** the time of the first error and the call to these interfaces. +** When that happens, the second error will be reported since these +** interfaces always report the most recent result. To avoid +** this, each thread can obtain exclusive use of the [database connection] D +** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning +** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after +** all calls to the interfaces listed here are completed. +** +** If an interface fails with SQLITE_MISUSE, that means the interface +** was invoked incorrectly by the application. In that case, the +** error code and message may or may not be set. +** +** Requirements: +** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] +*/ +SQLITE_API int sqlite3_errcode(sqlite3 *db); +SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); +SQLITE_API const char *sqlite3_errmsg(sqlite3*); +SQLITE_API const void *sqlite3_errmsg16(sqlite3*); + +/* +** CAPI3REF: SQL Statement Object {H13000} <H13010> +** KEYWORDS: {prepared statement} {prepared statements} +** +** An instance of this object represents a single SQL statement. +** This object is variously known as a "prepared statement" or a +** "compiled SQL statement" or simply as a "statement". +** +** The life of a statement object goes something like this: +** +** <ol> +** <li> Create the object using [sqlite3_prepare_v2()] or a related +** function. +** <li> Bind values to [host parameters] using the sqlite3_bind_*() +** interfaces. +** <li> Run the SQL by calling [sqlite3_step()] one or more times. +** <li> Reset the statement using [sqlite3_reset()] then go back +** to step 2. Do this zero or more times. +** <li> Destroy the object using [sqlite3_finalize()]. +** </ol> +** +** Refer to documentation on individual methods above for additional +** information. +*/ +typedef struct sqlite3_stmt sqlite3_stmt; + +/* +** CAPI3REF: Run-time Limits {H12760} <S20600> +** +** This interface allows the size of various constructs to be limited +** on a connection by connection basis. The first parameter is the +** [database connection] whose limit is to be set or queried. The +** second parameter is one of the [limit categories] that define a +** class of constructs to be size limited. The third parameter is the +** new limit for that construct. The function returns the old limit. +** +** If the new limit is a negative number, the limit is unchanged. +** For the limit category of SQLITE_LIMIT_XYZ there is a +** [limits | hard upper bound] +** set by a compile-time C preprocessor macro named +** [limits | SQLITE_MAX_XYZ]. +** (The "_LIMIT_" in the name is changed to "_MAX_".) +** Attempts to increase a limit above its hard upper bound are +** silently truncated to the hard upper limit. +** +** Run time limits are intended for use in applications that manage +** both their own internal database and also databases that are controlled +** by untrusted external sources. An example application might be a +** web browser that has its own databases for storing history and +** separate databases controlled by JavaScript applications downloaded +** off the Internet. The internal databases can be given the +** large, default limits. Databases managed by external sources can +** be given much smaller limits designed to prevent a denial of service +** attack. Developers might also want to use the [sqlite3_set_authorizer()] +** interface to further control untrusted SQL. The size of the database +** created by an untrusted script can be contained using the +** [max_page_count] [PRAGMA]. +** +** New run-time limit categories may be added in future releases. +** +** Requirements: +** [H12762] [H12766] [H12769] +*/ +SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); + +/* +** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> +** KEYWORDS: {limit category} {*limit categories} +** +** These constants define various performance limits +** that can be lowered at run-time using [sqlite3_limit()]. +** The synopsis of the meanings of the various limits is shown below. +** Additional information is available at [limits | Limits in SQLite]. +** +** <dl> +** <dt>SQLITE_LIMIT_LENGTH</dt> +** <dd>The maximum size of any string or BLOB or table row.<dd> +** +** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> +** <dd>The maximum length of an SQL statement.</dd> +** +** <dt>SQLITE_LIMIT_COLUMN</dt> +** <dd>The maximum number of columns in a table definition or in the +** result set of a [SELECT] or the maximum number of columns in an index +** or in an ORDER BY or GROUP BY clause.</dd> +** +** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> +** <dd>The maximum depth of the parse tree on any expression.</dd> +** +** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> +** <dd>The maximum number of terms in a compound SELECT statement.</dd> +** +** <dt>SQLITE_LIMIT_VDBE_OP</dt> +** <dd>The maximum number of instructions in a virtual machine program +** used to implement an SQL statement.</dd> +** +** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> +** <dd>The maximum number of arguments on a function.</dd> +** +** <dt>SQLITE_LIMIT_ATTACHED</dt> +** <dd>The maximum number of [ATTACH | attached databases].</dd> +** +** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> +** <dd>The maximum length of the pattern argument to the [LIKE] or +** [GLOB] operators.</dd> +** +** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> +** <dd>The maximum number of variables in an SQL statement that can +** be bound.</dd> +** +** <dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> +** <dd>The maximum depth of recursion for triggers.</dd> +** </dl> +*/ +#define SQLITE_LIMIT_LENGTH 0 +#define SQLITE_LIMIT_SQL_LENGTH 1 +#define SQLITE_LIMIT_COLUMN 2 +#define SQLITE_LIMIT_EXPR_DEPTH 3 +#define SQLITE_LIMIT_COMPOUND_SELECT 4 +#define SQLITE_LIMIT_VDBE_OP 5 +#define SQLITE_LIMIT_FUNCTION_ARG 6 +#define SQLITE_LIMIT_ATTACHED 7 +#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 +#define SQLITE_LIMIT_VARIABLE_NUMBER 9 +#define SQLITE_LIMIT_TRIGGER_DEPTH 10 + +/* +** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> +** KEYWORDS: {SQL statement compiler} +** +** To execute an SQL query, it must first be compiled into a byte-code +** program using one of these routines. +** +** The first argument, "db", is a [database connection] obtained from a +** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or +** [sqlite3_open16()]. The database connection must not have been closed. +** +** The second argument, "zSql", is the statement to be compiled, encoded +** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() +** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() +** use UTF-16. +** +** If the nByte argument is less than zero, then zSql is read up to the +** first zero terminator. If nByte is non-negative, then it is the maximum +** number of bytes read from zSql. When nByte is non-negative, the +** zSql string ends at either the first '\000' or '\u0000' character or +** the nByte-th byte, whichever comes first. If the caller knows +** that the supplied string is nul-terminated, then there is a small +** performance advantage to be gained by passing an nByte parameter that +** is equal to the number of bytes in the input string <i>including</i> +** the nul-terminator bytes. +** +** If pzTail is not NULL then *pzTail is made to point to the first byte +** past the end of the first SQL statement in zSql. These routines only +** compile the first statement in zSql, so *pzTail is left pointing to +** what remains uncompiled. +** +** *ppStmt is left pointing to a compiled [prepared statement] that can be +** executed using [sqlite3_step()]. If there is an error, *ppStmt is set +** to NULL. If the input text contains no SQL (if the input is an empty +** string or a comment) then *ppStmt is set to NULL. +** The calling procedure is responsible for deleting the compiled +** SQL statement using [sqlite3_finalize()] after it has finished with it. +** ppStmt may not be NULL. +** +** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. +** +** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are +** recommended for all new programs. The two older interfaces are retained +** for backwards compatibility, but their use is discouraged. +** In the "v2" interfaces, the prepared statement +** that is returned (the [sqlite3_stmt] object) contains a copy of the +** original SQL text. This causes the [sqlite3_step()] interface to +** behave a differently in three ways: +** +** <ol> +** <li> +** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it +** always used to do, [sqlite3_step()] will automatically recompile the SQL +** statement and try to run it again. If the schema has changed in +** a way that makes the statement no longer valid, [sqlite3_step()] will still +** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is +** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the +** error go away. Note: use [sqlite3_errmsg()] to find the text +** of the parsing error that results in an [SQLITE_SCHEMA] return. +** </li> +** +** <li> +** When an error occurs, [sqlite3_step()] will return one of the detailed +** [error codes] or [extended error codes]. The legacy behavior was that +** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code +** and you would have to make a second call to [sqlite3_reset()] in order +** to find the underlying cause of the problem. With the "v2" prepare +** interfaces, the underlying reason for the error is returned immediately. +** </li> +** +** <li> +** ^If the value of a [parameter | host parameter] in the WHERE clause might +** change the query plan for a statement, then the statement may be +** automatically recompiled (as if there had been a schema change) on the first +** [sqlite3_step()] call following any change to the +** [sqlite3_bind_text | bindings] of the [parameter]. +** </li> +** </ol> +** +** Requirements: +** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] +** +*/ +SQLITE_API int sqlite3_prepare( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +SQLITE_API int sqlite3_prepare_v2( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +SQLITE_API int sqlite3_prepare16( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); +SQLITE_API int sqlite3_prepare16_v2( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); + +/* +** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> +** +** This interface can be used to retrieve a saved copy of the original +** SQL text used to create a [prepared statement] if that statement was +** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. +** +** Requirements: +** [H13101] [H13102] [H13103] +*/ +SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> +** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} +** +** SQLite uses the sqlite3_value object to represent all values +** that can be stored in a database table. SQLite uses dynamic typing +** for the values it stores. Values stored in sqlite3_value objects +** can be integers, floating point values, strings, BLOBs, or NULL. +** +** An sqlite3_value object may be either "protected" or "unprotected". +** Some interfaces require a protected sqlite3_value. Other interfaces +** will accept either a protected or an unprotected sqlite3_value. +** Every interface that accepts sqlite3_value arguments specifies +** whether or not it requires a protected sqlite3_value. +** +** The terms "protected" and "unprotected" refer to whether or not +** a mutex is held. A internal mutex is held for a protected +** sqlite3_value object but no mutex is held for an unprotected +** sqlite3_value object. If SQLite is compiled to be single-threaded +** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) +** or if SQLite is run in one of reduced mutex modes +** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] +** then there is no distinction between protected and unprotected +** sqlite3_value objects and they can be used interchangeably. However, +** for maximum code portability it is recommended that applications +** still make the distinction between between protected and unprotected +** sqlite3_value objects even when not strictly required. +** +** The sqlite3_value objects that are passed as parameters into the +** implementation of [application-defined SQL functions] are protected. +** The sqlite3_value object returned by +** [sqlite3_column_value()] is unprotected. +** Unprotected sqlite3_value objects may only be used with +** [sqlite3_result_value()] and [sqlite3_bind_value()]. +** The [sqlite3_value_blob | sqlite3_value_type()] family of +** interfaces require protected sqlite3_value objects. +*/ +typedef struct Mem sqlite3_value; + +/* +** CAPI3REF: SQL Function Context Object {H16001} <S20200> +** +** The context in which an SQL function executes is stored in an +** sqlite3_context object. A pointer to an sqlite3_context object +** is always first parameter to [application-defined SQL functions]. +** The application-defined SQL function implementation will pass this +** pointer through into calls to [sqlite3_result_int | sqlite3_result()], +** [sqlite3_aggregate_context()], [sqlite3_user_data()], +** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], +** and/or [sqlite3_set_auxdata()]. +*/ +typedef struct sqlite3_context sqlite3_context; + +/* +** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> +** KEYWORDS: {host parameter} {host parameters} {host parameter name} +** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} +** +** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, +** literals may be replaced by a [parameter] that matches one of following +** templates: +** +** <ul> +** <li> ? +** <li> ?NNN +** <li> :VVV +** <li> @VVV +** <li> $VVV +** </ul> +** +** In the templates above, NNN represents an integer literal, +** and VVV represents an alphanumeric identifer. The values of these +** parameters (also called "host parameter names" or "SQL parameters") +** can be set using the sqlite3_bind_*() routines defined here. +** +** The first argument to the sqlite3_bind_*() routines is always +** a pointer to the [sqlite3_stmt] object returned from +** [sqlite3_prepare_v2()] or its variants. +** +** The second argument is the index of the SQL parameter to be set. +** The leftmost SQL parameter has an index of 1. When the same named +** SQL parameter is used more than once, second and subsequent +** occurrences have the same index as the first occurrence. +** The index for named parameters can be looked up using the +** [sqlite3_bind_parameter_index()] API if desired. The index +** for "?NNN" parameters is the value of NNN. +** The NNN value must be between 1 and the [sqlite3_limit()] +** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). +** +** The third argument is the value to bind to the parameter. +** +** In those routines that have a fourth argument, its value is the +** number of bytes in the parameter. To be clear: the value is the +** number of <u>bytes</u> in the value, not the number of characters. +** If the fourth parameter is negative, the length of the string is +** the number of bytes up to the first zero terminator. +** +** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and +** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or +** string after SQLite has finished with it. If the fifth argument is +** the special value [SQLITE_STATIC], then SQLite assumes that the +** information is in static, unmanaged space and does not need to be freed. +** If the fifth argument has the value [SQLITE_TRANSIENT], then +** SQLite makes its own private copy of the data immediately, before +** the sqlite3_bind_*() routine returns. +** +** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that +** is filled with zeroes. A zeroblob uses a fixed amount of memory +** (just an integer to hold its size) while it is being processed. +** Zeroblobs are intended to serve as placeholders for BLOBs whose +** content is later written using +** [sqlite3_blob_open | incremental BLOB I/O] routines. +** A negative value for the zeroblob results in a zero-length BLOB. +** +** The sqlite3_bind_*() routines must be called after +** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and +** before [sqlite3_step()]. +** Bindings are not cleared by the [sqlite3_reset()] routine. +** Unbound parameters are interpreted as NULL. +** +** These routines return [SQLITE_OK] on success or an error code if +** anything goes wrong. [SQLITE_RANGE] is returned if the parameter +** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. +** [SQLITE_MISUSE] might be returned if these routines are called on a +** virtual machine that is the wrong state or which has already been finalized. +** Detection of misuse is unreliable. Applications should not depend +** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a +** a logic error in the application. Future versions of SQLite might +** panic rather than return SQLITE_MISUSE. +** +** See also: [sqlite3_bind_parameter_count()], +** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. +** +** Requirements: +** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] +** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] +** +*/ +SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); +SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); +SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); +SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); +SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); +SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); +SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); +SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); +SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); + +/* +** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> +** +** This routine can be used to find the number of [SQL parameters] +** in a [prepared statement]. SQL parameters are tokens of the +** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as +** placeholders for values that are [sqlite3_bind_blob | bound] +** to the parameters at a later time. +** +** This routine actually returns the index of the largest (rightmost) +** parameter. For all forms except ?NNN, this will correspond to the +** number of unique parameters. If parameters of the ?NNN are used, +** there may be gaps in the list. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_name()], and +** [sqlite3_bind_parameter_index()]. +** +** Requirements: +** [H13601] +*/ +SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); + +/* +** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> +** +** This routine returns a pointer to the name of the n-th +** [SQL parameter] in a [prepared statement]. +** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" +** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" +** respectively. +** In other words, the initial ":" or "$" or "@" or "?" +** is included as part of the name. +** Parameters of the form "?" without a following integer have no name +** and are also referred to as "anonymous parameters". +** +** The first host parameter has an index of 1, not 0. +** +** If the value n is out of range or if the n-th parameter is +** nameless, then NULL is returned. The returned string is +** always in UTF-8 encoding even if the named parameter was +** originally specified as UTF-16 in [sqlite3_prepare16()] or +** [sqlite3_prepare16_v2()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_index()]. +** +** Requirements: +** [H13621] +*/ +SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); + +/* +** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> +** +** Return the index of an SQL parameter given its name. The +** index value returned is suitable for use as the second +** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero +** is returned if no matching parameter is found. The parameter +** name must be given in UTF-8 even if the original statement +** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_index()]. +** +** Requirements: +** [H13641] +*/ +SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); + +/* +** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> +** +** Contrary to the intuition of many, [sqlite3_reset()] does not reset +** the [sqlite3_bind_blob | bindings] on a [prepared statement]. +** Use this routine to reset all host parameters to NULL. +** +** Requirements: +** [H13661] +*/ +SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); + +/* +** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> +** +** Return the number of columns in the result set returned by the +** [prepared statement]. This routine returns 0 if pStmt is an SQL +** statement that does not return data (for example an [UPDATE]). +** +** Requirements: +** [H13711] +*/ +SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Column Names In A Result Set {H13720} <S10700> +** +** These routines return the name assigned to a particular column +** in the result set of a [SELECT] statement. The sqlite3_column_name() +** interface returns a pointer to a zero-terminated UTF-8 string +** and sqlite3_column_name16() returns a pointer to a zero-terminated +** UTF-16 string. The first parameter is the [prepared statement] +** that implements the [SELECT] statement. The second parameter is the +** column number. The leftmost column is number 0. +** +** The returned string pointer is valid until either the [prepared statement] +** is destroyed by [sqlite3_finalize()] or until the next call to +** sqlite3_column_name() or sqlite3_column_name16() on the same column. +** +** If sqlite3_malloc() fails during the processing of either routine +** (for example during a conversion from UTF-8 to UTF-16) then a +** NULL pointer is returned. +** +** The name of a result column is the value of the "AS" clause for +** that column, if there is an AS clause. If there is no AS clause +** then the name of the column is unspecified and may change from +** one release of SQLite to the next. +** +** Requirements: +** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] +*/ +SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); +SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); + +/* +** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> +** +** These routines provide a means to determine what column of what +** table in which database a result of a [SELECT] statement comes from. +** The name of the database or table or column can be returned as +** either a UTF-8 or UTF-16 string. The _database_ routines return +** the database name, the _table_ routines return the table name, and +** the origin_ routines return the column name. +** The returned string is valid until the [prepared statement] is destroyed +** using [sqlite3_finalize()] or until the same information is requested +** again in a different encoding. +** +** The names returned are the original un-aliased names of the +** database, table, and column. +** +** The first argument to the following calls is a [prepared statement]. +** These functions return information about the Nth column returned by +** the statement, where N is the second function argument. +** +** If the Nth column returned by the statement is an expression or +** subquery and is not a column value, then all of these functions return +** NULL. These routine might also return NULL if a memory allocation error +** occurs. Otherwise, they return the name of the attached database, table +** and column that query result column was extracted from. +** +** As with all other SQLite APIs, those postfixed with "16" return +** UTF-16 encoded strings, the other functions return UTF-8. {END} +** +** These APIs are only available if the library was compiled with the +** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. +** +** {A13751} +** If two or more threads call one or more of these routines against the same +** prepared statement and column at the same time then the results are +** undefined. +** +** Requirements: +** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] +** +** If two or more threads call one or more +** [sqlite3_column_database_name | column metadata interfaces] +** for the same [prepared statement] and result column +** at the same time then the results are undefined. +*/ +SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); +SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); +SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); +SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); +SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); +SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> +** +** The first parameter is a [prepared statement]. +** If this statement is a [SELECT] statement and the Nth column of the +** returned result set of that [SELECT] is a table column (not an +** expression or subquery) then the declared type of the table +** column is returned. If the Nth column of the result set is an +** expression or subquery, then a NULL pointer is returned. +** The returned string is always UTF-8 encoded. {END} +** +** For example, given the database schema: +** +** CREATE TABLE t1(c1 VARIANT); +** +** and the following statement to be compiled: +** +** SELECT c1 + 1, c1 FROM t1; +** +** this routine would return the string "VARIANT" for the second result +** column (i==1), and a NULL pointer for the first result column (i==0). +** +** SQLite uses dynamic run-time typing. So just because a column +** is declared to contain a particular type does not mean that the +** data stored in that column is of the declared type. SQLite is +** strongly typed, but the typing is dynamic not static. Type +** is associated with individual values, not with the containers +** used to hold those values. +** +** Requirements: +** [H13761] [H13762] [H13763] +*/ +SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); +SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> +** +** After a [prepared statement] has been prepared using either +** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy +** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function +** must be called one or more times to evaluate the statement. +** +** The details of the behavior of the sqlite3_step() interface depend +** on whether the statement was prepared using the newer "v2" interface +** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy +** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the +** new "v2" interface is recommended for new applications but the legacy +** interface will continue to be supported. +** +** In the legacy interface, the return value will be either [SQLITE_BUSY], +** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. +** With the "v2" interface, any of the other [result codes] or +** [extended result codes] might be returned as well. +** +** [SQLITE_BUSY] means that the database engine was unable to acquire the +** database locks it needs to do its job. If the statement is a [COMMIT] +** or occurs outside of an explicit transaction, then you can retry the +** statement. If the statement is not a [COMMIT] and occurs within a +** explicit transaction then you should rollback the transaction before +** continuing. +** +** [SQLITE_DONE] means that the statement has finished executing +** successfully. sqlite3_step() should not be called again on this virtual +** machine without first calling [sqlite3_reset()] to reset the virtual +** machine back to its initial state. +** +** If the SQL statement being executed returns any data, then [SQLITE_ROW] +** is returned each time a new row of data is ready for processing by the +** caller. The values may be accessed using the [column access functions]. +** sqlite3_step() is called again to retrieve the next row of data. +** +** [SQLITE_ERROR] means that a run-time error (such as a constraint +** violation) has occurred. sqlite3_step() should not be called again on +** the VM. More information may be found by calling [sqlite3_errmsg()]. +** With the legacy interface, a more specific error code (for example, +** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) +** can be obtained by calling [sqlite3_reset()] on the +** [prepared statement]. In the "v2" interface, +** the more specific error code is returned directly by sqlite3_step(). +** +** [SQLITE_MISUSE] means that the this routine was called inappropriately. +** Perhaps it was called on a [prepared statement] that has +** already been [sqlite3_finalize | finalized] or on one that had +** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could +** be the case that the same database connection is being used by two or +** more threads at the same moment in time. +** +** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() +** API always returns a generic error code, [SQLITE_ERROR], following any +** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call +** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the +** specific [error codes] that better describes the error. +** We admit that this is a goofy design. The problem has been fixed +** with the "v2" interface. If you prepare all of your SQL statements +** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead +** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, +** then the more specific [error codes] are returned directly +** by sqlite3_step(). The use of the "v2" interface is recommended. +** +** Requirements: +** [H13202] [H15304] [H15306] [H15308] [H15310] +*/ +SQLITE_API int sqlite3_step(sqlite3_stmt*); + +/* +** CAPI3REF: Number of columns in a result set {H13770} <S10700> +** +** Returns the number of values in the current row of the result set. +** +** Requirements: +** [H13771] [H13772] +*/ +SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> +** KEYWORDS: SQLITE_TEXT +** +** {H10266} Every value in SQLite has one of five fundamental datatypes: +** +** <ul> +** <li> 64-bit signed integer +** <li> 64-bit IEEE floating point number +** <li> string +** <li> BLOB +** <li> NULL +** </ul> {END} +** +** These constants are codes for each of those types. +** +** Note that the SQLITE_TEXT constant was also used in SQLite version 2 +** for a completely different meaning. Software that links against both +** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not +** SQLITE_TEXT. +*/ +#define SQLITE_INTEGER 1 +#define SQLITE_FLOAT 2 +#define SQLITE_BLOB 4 +#define SQLITE_NULL 5 +#ifdef SQLITE_TEXT +# undef SQLITE_TEXT +#else +# define SQLITE_TEXT 3 +#endif +#define SQLITE3_TEXT 3 + +/* +** CAPI3REF: Result Values From A Query {H13800} <S10700> +** KEYWORDS: {column access functions} +** +** These routines form the "result set query" interface. +** +** These routines return information about a single column of the current +** result row of a query. In every case the first argument is a pointer +** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] +** that was returned from [sqlite3_prepare_v2()] or one of its variants) +** and the second argument is the index of the column for which information +** should be returned. The leftmost column of the result set has the index 0. +** The number of columns in the result can be determined using +** [sqlite3_column_count()]. +** +** If the SQL statement does not currently point to a valid row, or if the +** column index is out of range, the result is undefined. +** These routines may only be called when the most recent call to +** [sqlite3_step()] has returned [SQLITE_ROW] and neither +** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. +** If any of these routines are called after [sqlite3_reset()] or +** [sqlite3_finalize()] or after [sqlite3_step()] has returned +** something other than [SQLITE_ROW], the results are undefined. +** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] +** are called from a different thread while any of these routines +** are pending, then the results are undefined. +** +** The sqlite3_column_type() routine returns the +** [SQLITE_INTEGER | datatype code] for the initial data type +** of the result column. The returned value is one of [SQLITE_INTEGER], +** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value +** returned by sqlite3_column_type() is only meaningful if no type +** conversions have occurred as described below. After a type conversion, +** the value returned by sqlite3_column_type() is undefined. Future +** versions of SQLite may change the behavior of sqlite3_column_type() +** following a type conversion. +** +** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() +** routine returns the number of bytes in that BLOB or string. +** If the result is a UTF-16 string, then sqlite3_column_bytes() converts +** the string to UTF-8 and then returns the number of bytes. +** If the result is a numeric value then sqlite3_column_bytes() uses +** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns +** the number of bytes in that string. +** The value returned does not include the zero terminator at the end +** of the string. For clarity: the value returned is the number of +** bytes in the string, not the number of characters. +** +** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), +** even empty strings, are always zero terminated. The return +** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary +** pointer, possibly even a NULL pointer. +** +** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() +** but leaves the result in UTF-16 in native byte order instead of UTF-8. +** The zero terminator is not included in this count. +** +** The object returned by [sqlite3_column_value()] is an +** [unprotected sqlite3_value] object. An unprotected sqlite3_value object +** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. +** If the [unprotected sqlite3_value] object returned by +** [sqlite3_column_value()] is used in any other way, including calls +** to routines like [sqlite3_value_int()], [sqlite3_value_text()], +** or [sqlite3_value_bytes()], then the behavior is undefined. +** +** These routines attempt to convert the value where appropriate. For +** example, if the internal representation is FLOAT and a text result +** is requested, [sqlite3_snprintf()] is used internally to perform the +** conversion automatically. The following table details the conversions +** that are applied: +** +** <blockquote> +** <table border="1"> +** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion +** +** <tr><td> NULL <td> INTEGER <td> Result is 0 +** <tr><td> NULL <td> FLOAT <td> Result is 0.0 +** <tr><td> NULL <td> TEXT <td> Result is NULL pointer +** <tr><td> NULL <td> BLOB <td> Result is NULL pointer +** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float +** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer +** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT +** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer +** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float +** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT +** <tr><td> TEXT <td> INTEGER <td> Use atoi() +** <tr><td> TEXT <td> FLOAT <td> Use atof() +** <tr><td> TEXT <td> BLOB <td> No change +** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() +** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() +** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed +** </table> +** </blockquote> +** +** The table above makes reference to standard C library functions atoi() +** and atof(). SQLite does not really use these functions. It has its +** own equivalent internal routines. The atoi() and atof() names are +** used in the table for brevity and because they are familiar to most +** C programmers. +** +** Note that when type conversions occur, pointers returned by prior +** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or +** sqlite3_column_text16() may be invalidated. +** Type conversions and pointer invalidations might occur +** in the following cases: +** +** <ul> +** <li> The initial content is a BLOB and sqlite3_column_text() or +** sqlite3_column_text16() is called. A zero-terminator might +** need to be added to the string.</li> +** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or +** sqlite3_column_text16() is called. The content must be converted +** to UTF-16.</li> +** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or +** sqlite3_column_text() is called. The content must be converted +** to UTF-8.</li> +** </ul> +** +** Conversions between UTF-16be and UTF-16le are always done in place and do +** not invalidate a prior pointer, though of course the content of the buffer +** that the prior pointer points to will have been modified. Other kinds +** of conversion are done in place when it is possible, but sometimes they +** are not possible and in those cases prior pointers are invalidated. +** +** The safest and easiest to remember policy is to invoke these routines +** in one of the following ways: +** +** <ul> +** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> +** </ul> +** +** In other words, you should call sqlite3_column_text(), +** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result +** into the desired format, then invoke sqlite3_column_bytes() or +** sqlite3_column_bytes16() to find the size of the result. Do not mix calls +** to sqlite3_column_text() or sqlite3_column_blob() with calls to +** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() +** with calls to sqlite3_column_bytes(). +** +** The pointers returned are valid until a type conversion occurs as +** described above, or until [sqlite3_step()] or [sqlite3_reset()] or +** [sqlite3_finalize()] is called. The memory space used to hold strings +** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned +** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into +** [sqlite3_free()]. +** +** If a memory allocation error occurs during the evaluation of any +** of these routines, a default value is returned. The default value +** is either the integer 0, the floating point number 0.0, or a NULL +** pointer. Subsequent calls to [sqlite3_errcode()] will return +** [SQLITE_NOMEM]. +** +** Requirements: +** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] +** [H13827] [H13830] +*/ +SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); +SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); +SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); +SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); +SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); +SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); + +/* +** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> +** +** The sqlite3_finalize() function is called to delete a [prepared statement]. +** If the statement was executed successfully or not executed at all, then +** SQLITE_OK is returned. If execution of the statement failed then an +** [error code] or [extended error code] is returned. +** +** This routine can be called at any point during the execution of the +** [prepared statement]. If the virtual machine has not +** completed execution when this routine is called, that is like +** encountering an error or an [sqlite3_interrupt | interrupt]. +** Incomplete updates may be rolled back and transactions canceled, +** depending on the circumstances, and the +** [error code] returned will be [SQLITE_ABORT]. +** +** Requirements: +** [H11302] [H11304] +*/ +SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> +** +** The sqlite3_reset() function is called to reset a [prepared statement] +** object back to its initial state, ready to be re-executed. +** Any SQL statement variables that had values bound to them using +** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. +** Use [sqlite3_clear_bindings()] to reset the bindings. +** +** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S +** back to the beginning of its program. +** +** {H11334} If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], +** or if [sqlite3_step(S)] has never before been called on S, +** then [sqlite3_reset(S)] returns [SQLITE_OK]. +** +** {H11336} If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S indicated an error, then +** [sqlite3_reset(S)] returns an appropriate [error code]. +** +** {H11338} The [sqlite3_reset(S)] interface does not change the values +** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. +*/ +SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> +** KEYWORDS: {function creation routines} +** KEYWORDS: {application-defined SQL function} +** KEYWORDS: {application-defined SQL functions} +** +** These two functions (collectively known as "function creation routines") +** are used to add SQL functions or aggregates or to redefine the behavior +** of existing SQL functions or aggregates. The only difference between the +** two is that the second parameter, the name of the (scalar) function or +** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 +** for sqlite3_create_function16(). +** +** The first parameter is the [database connection] to which the SQL +** function is to be added. If a single program uses more than one database +** connection internally, then SQL functions must be added individually to +** each database connection. +** +** The second parameter is the name of the SQL function to be created or +** redefined. The length of the name is limited to 255 bytes, exclusive of +** the zero-terminator. Note that the name length limit is in bytes, not +** characters. Any attempt to create a function with a longer name +** will result in [SQLITE_ERROR] being returned. +** +** The third parameter (nArg) +** is the number of arguments that the SQL function or +** aggregate takes. If this parameter is -1, then the SQL function or +** aggregate may take any number of arguments between 0 and the limit +** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third +** parameter is less than -1 or greater than 127 then the behavior is +** undefined. +** +** The fourth parameter, eTextRep, specifies what +** [SQLITE_UTF8 | text encoding] this SQL function prefers for +** its parameters. Any SQL function implementation should be able to work +** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be +** more efficient with one encoding than another. An application may +** invoke sqlite3_create_function() or sqlite3_create_function16() multiple +** times with the same function but with different values of eTextRep. +** When multiple implementations of the same function are available, SQLite +** will pick the one that involves the least amount of data conversion. +** If there is only a single implementation which does not care what text +** encoding is used, then the fourth argument should be [SQLITE_ANY]. +** +** The fifth parameter is an arbitrary pointer. The implementation of the +** function can gain access to this pointer using [sqlite3_user_data()]. +** +** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are +** pointers to C-language functions that implement the SQL function or +** aggregate. A scalar SQL function requires an implementation of the xFunc +** callback only, NULL pointers should be passed as the xStep and xFinal +** parameters. An aggregate SQL function requires an implementation of xStep +** and xFinal and NULL should be passed for xFunc. To delete an existing +** SQL function or aggregate, pass NULL for all three function callbacks. +** +** It is permitted to register multiple implementations of the same +** functions with the same name but with either differing numbers of +** arguments or differing preferred text encodings. SQLite will use +** the implementation that most closely matches the way in which the +** SQL function is used. A function implementation with a non-negative +** nArg parameter is a better match than a function implementation with +** a negative nArg. A function where the preferred text encoding +** matches the database encoding is a better +** match than a function where the encoding is different. +** A function where the encoding difference is between UTF16le and UTF16be +** is a closer match than a function where the encoding difference is +** between UTF8 and UTF16. +** +** Built-in functions may be overloaded by new application-defined functions. +** The first application-defined function with a given name overrides all +** built-in functions in the same [database connection] with the same name. +** Subsequent application-defined functions of the same name only override +** prior application-defined functions that are an exact match for the +** number of parameters and preferred encoding. +** +** An application-defined function is permitted to call other +** SQLite interfaces. However, such calls must not +** close the database connection nor finalize or reset the prepared +** statement in which the function is running. +** +** Requirements: +** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16127] +** [H16130] [H16133] [H16136] [H16139] [H16142] +*/ +SQLITE_API int sqlite3_create_function( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); +SQLITE_API int sqlite3_create_function16( + sqlite3 *db, + const void *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); + +/* +** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> +** +** These constant define integer codes that represent the various +** text encodings supported by SQLite. +*/ +#define SQLITE_UTF8 1 +#define SQLITE_UTF16LE 2 +#define SQLITE_UTF16BE 3 +#define SQLITE_UTF16 4 /* Use native byte order */ +#define SQLITE_ANY 5 /* sqlite3_create_function only */ +#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ + +/* +** CAPI3REF: Deprecated Functions +** DEPRECATED +** +** These functions are [deprecated]. In order to maintain +** backwards compatibility with older code, these functions continue +** to be supported. However, new applications should avoid +** the use of these functions. To help encourage people to avoid +** using these functions, we are not going to tell you what they do. +*/ +#ifndef SQLITE_OMIT_DEPRECATED +SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); +SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); +SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); +SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); +SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); +SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); +#endif + +/* +** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> +** +** The C-language implementation of SQL functions and aggregates uses +** this set of interface routines to access the parameter values on +** the function or aggregate. +** +** The xFunc (for scalar functions) or xStep (for aggregates) parameters +** to [sqlite3_create_function()] and [sqlite3_create_function16()] +** define callbacks that implement the SQL functions and aggregates. +** The 4th parameter to these callbacks is an array of pointers to +** [protected sqlite3_value] objects. There is one [sqlite3_value] object for +** each parameter to the SQL function. These routines are used to +** extract values from the [sqlite3_value] objects. +** +** These routines work only with [protected sqlite3_value] objects. +** Any attempt to use these routines on an [unprotected sqlite3_value] +** object results in undefined behavior. +** +** These routines work just like the corresponding [column access functions] +** except that these routines take a single [protected sqlite3_value] object +** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. +** +** The sqlite3_value_text16() interface extracts a UTF-16 string +** in the native byte-order of the host machine. The +** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces +** extract UTF-16 strings as big-endian and little-endian respectively. +** +** The sqlite3_value_numeric_type() interface attempts to apply +** numeric affinity to the value. This means that an attempt is +** made to convert the value to an integer or floating point. If +** such a conversion is possible without loss of information (in other +** words, if the value is a string that looks like a number) +** then the conversion is performed. Otherwise no conversion occurs. +** The [SQLITE_INTEGER | datatype] after conversion is returned. +** +** Please pay particular attention to the fact that the pointer returned +** from [sqlite3_value_blob()], [sqlite3_value_text()], or +** [sqlite3_value_text16()] can be invalidated by a subsequent call to +** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], +** or [sqlite3_value_text16()]. +** +** These routines must be called from the same thread as +** the SQL function that supplied the [sqlite3_value*] parameters. +** +** Requirements: +** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] +** [H15127] [H15130] [H15133] [H15136] +*/ +SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); +SQLITE_API int sqlite3_value_bytes(sqlite3_value*); +SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); +SQLITE_API double sqlite3_value_double(sqlite3_value*); +SQLITE_API int sqlite3_value_int(sqlite3_value*); +SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); +SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); +SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); +SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); +SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); +SQLITE_API int sqlite3_value_type(sqlite3_value*); +SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); + +/* +** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> +** +** The implementation of aggregate SQL functions use this routine to allocate +** a structure for storing their state. +** +** The first time the sqlite3_aggregate_context() routine is called for a +** particular aggregate, SQLite allocates nBytes of memory, zeroes out that +** memory, and returns a pointer to it. On second and subsequent calls to +** sqlite3_aggregate_context() for the same aggregate function index, +** the same buffer is returned. The implementation of the aggregate can use +** the returned buffer to accumulate data. +** +** SQLite automatically frees the allocated buffer when the aggregate +** query concludes. +** +** The first parameter should be a copy of the +** [sqlite3_context | SQL function context] that is the first parameter +** to the callback routine that implements the aggregate function. +** +** This routine must be called from the same thread in which +** the aggregate SQL function is running. +** +** Requirements: +** [H16211] [H16213] [H16215] [H16217] +*/ +SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); + +/* +** CAPI3REF: User Data For Functions {H16240} <S20200> +** +** The sqlite3_user_data() interface returns a copy of +** the pointer that was the pUserData parameter (the 5th parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. {END} +** +** This routine must be called from the same thread in which +** the application-defined function is running. +** +** Requirements: +** [H16243] +*/ +SQLITE_API void *sqlite3_user_data(sqlite3_context*); + +/* +** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> +** +** The sqlite3_context_db_handle() interface returns a copy of +** the pointer to the [database connection] (the 1st parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. +** +** Requirements: +** [H16253] +*/ +SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); + +/* +** CAPI3REF: Function Auxiliary Data {H16270} <S20200> +** +** The following two functions may be used by scalar SQL functions to +** associate metadata with argument values. If the same value is passed to +** multiple invocations of the same SQL function during query execution, under +** some circumstances the associated metadata may be preserved. This may +** be used, for example, to add a regular-expression matching scalar +** function. The compiled version of the regular expression is stored as +** metadata associated with the SQL value passed as the regular expression +** pattern. The compiled regular expression can be reused on multiple +** invocations of the same function so that the original pattern string +** does not need to be recompiled on each invocation. +** +** The sqlite3_get_auxdata() interface returns a pointer to the metadata +** associated by the sqlite3_set_auxdata() function with the Nth argument +** value to the application-defined function. If no metadata has been ever +** been set for the Nth argument of the function, or if the corresponding +** function parameter has changed since the meta-data was set, +** then sqlite3_get_auxdata() returns a NULL pointer. +** +** The sqlite3_set_auxdata() interface saves the metadata +** pointed to by its 3rd parameter as the metadata for the N-th +** argument of the application-defined function. Subsequent +** calls to sqlite3_get_auxdata() might return this data, if it has +** not been destroyed. +** If it is not NULL, SQLite will invoke the destructor +** function given by the 4th parameter to sqlite3_set_auxdata() on +** the metadata when the corresponding function parameter changes +** or when the SQL statement completes, whichever comes first. +** +** SQLite is free to call the destructor and drop metadata on any +** parameter of any function at any time. The only guarantee is that +** the destructor will be called before the metadata is dropped. +** +** In practice, metadata is preserved between function calls for +** expressions that are constant at compile time. This includes literal +** values and SQL variables. +** +** These routines must be called from the same thread in which +** the SQL function is running. +** +** Requirements: +** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] +*/ +SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); +SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); + + +/* +** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> +** +** These are special values for the destructor that is passed in as the +** final argument to routines like [sqlite3_result_blob()]. If the destructor +** argument is SQLITE_STATIC, it means that the content pointer is constant +** and will never change. It does not need to be destroyed. The +** SQLITE_TRANSIENT value means that the content will likely change in +** the near future and that SQLite should make its own private copy of +** the content before returning. +** +** The typedef is necessary to work around problems in certain +** C++ compilers. See ticket #2191. +*/ +typedef void (*sqlite3_destructor_type)(void*); +#define SQLITE_STATIC ((sqlite3_destructor_type)0) +#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) + +/* +** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> +** +** These routines are used by the xFunc or xFinal callbacks that +** implement SQL functions and aggregates. See +** [sqlite3_create_function()] and [sqlite3_create_function16()] +** for additional information. +** +** These functions work very much like the [parameter binding] family of +** functions used to bind values to host parameters in prepared statements. +** Refer to the [SQL parameter] documentation for additional information. +** +** The sqlite3_result_blob() interface sets the result from +** an application-defined function to be the BLOB whose content is pointed +** to by the second parameter and which is N bytes long where N is the +** third parameter. +** +** The sqlite3_result_zeroblob() interfaces set the result of +** the application-defined function to be a BLOB containing all zero +** bytes and N bytes in size, where N is the value of the 2nd parameter. +** +** The sqlite3_result_double() interface sets the result from +** an application-defined function to be a floating point value specified +** by its 2nd argument. +** +** The sqlite3_result_error() and sqlite3_result_error16() functions +** cause the implemented SQL function to throw an exception. +** SQLite uses the string pointed to by the +** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() +** as the text of an error message. SQLite interprets the error +** message string from sqlite3_result_error() as UTF-8. SQLite +** interprets the string from sqlite3_result_error16() as UTF-16 in native +** byte order. If the third parameter to sqlite3_result_error() +** or sqlite3_result_error16() is negative then SQLite takes as the error +** message all text up through the first zero character. +** If the third parameter to sqlite3_result_error() or +** sqlite3_result_error16() is non-negative then SQLite takes that many +** bytes (not characters) from the 2nd parameter as the error message. +** The sqlite3_result_error() and sqlite3_result_error16() +** routines make a private copy of the error message text before +** they return. Hence, the calling function can deallocate or +** modify the text after they return without harm. +** The sqlite3_result_error_code() function changes the error code +** returned by SQLite as a result of an error in a function. By default, +** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() +** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. +** +** The sqlite3_result_toobig() interface causes SQLite to throw an error +** indicating that a string or BLOB is to long to represent. +** +** The sqlite3_result_nomem() interface causes SQLite to throw an error +** indicating that a memory allocation failed. +** +** The sqlite3_result_int() interface sets the return value +** of the application-defined function to be the 32-bit signed integer +** value given in the 2nd argument. +** The sqlite3_result_int64() interface sets the return value +** of the application-defined function to be the 64-bit signed integer +** value given in the 2nd argument. +** +** The sqlite3_result_null() interface sets the return value +** of the application-defined function to be NULL. +** +** The sqlite3_result_text(), sqlite3_result_text16(), +** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces +** set the return value of the application-defined function to be +** a text string which is represented as UTF-8, UTF-16 native byte order, +** UTF-16 little endian, or UTF-16 big endian, respectively. +** SQLite takes the text result from the application from +** the 2nd parameter of the sqlite3_result_text* interfaces. +** If the 3rd parameter to the sqlite3_result_text* interfaces +** is negative, then SQLite takes result text from the 2nd parameter +** through the first zero character. +** If the 3rd parameter to the sqlite3_result_text* interfaces +** is non-negative, then as many bytes (not characters) of the text +** pointed to by the 2nd parameter are taken as the application-defined +** function result. +** If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that +** function as the destructor on the text or BLOB result when it has +** finished using that result. +** If the 4th parameter to the sqlite3_result_text* interfaces or to +** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite +** assumes that the text or BLOB result is in constant space and does not +** copy the content of the parameter nor call a destructor on the content +** when it has finished using that result. +** If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT +** then SQLite makes a copy of the result into space obtained from +** from [sqlite3_malloc()] before it returns. +** +** The sqlite3_result_value() interface sets the result of +** the application-defined function to be a copy the +** [unprotected sqlite3_value] object specified by the 2nd parameter. The +** sqlite3_result_value() interface makes a copy of the [sqlite3_value] +** so that the [sqlite3_value] specified in the parameter may change or +** be deallocated after sqlite3_result_value() returns without harm. +** A [protected sqlite3_value] object may always be used where an +** [unprotected sqlite3_value] object is required, so either +** kind of [sqlite3_value] object can be used with this interface. +** +** If these routines are called from within the different thread +** than the one containing the application-defined function that received +** the [sqlite3_context] pointer, the results are undefined. +** +** Requirements: +** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] +** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] +** [H16451] [H16454] [H16457] [H16460] [H16463] +*/ +SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); +SQLITE_API void sqlite3_result_double(sqlite3_context*, double); +SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); +SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); +SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); +SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); +SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); +SQLITE_API void sqlite3_result_int(sqlite3_context*, int); +SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); +SQLITE_API void sqlite3_result_null(sqlite3_context*); +SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); +SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); +SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); +SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); +SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); +SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); + +/* +** CAPI3REF: Define New Collating Sequences {H16600} <S20300> +** +** These functions are used to add new collation sequences to the +** [database connection] specified as the first argument. +** +** The name of the new collation sequence is specified as a UTF-8 string +** for sqlite3_create_collation() and sqlite3_create_collation_v2() +** and a UTF-16 string for sqlite3_create_collation16(). In all cases +** the name is passed as the second function argument. +** +** The third argument may be one of the constants [SQLITE_UTF8], +** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied +** routine expects to be passed pointers to strings encoded using UTF-8, +** UTF-16 little-endian, or UTF-16 big-endian, respectively. The +** third argument might also be [SQLITE_UTF16] to indicate that the routine +** expects pointers to be UTF-16 strings in the native byte order, or the +** argument can be [SQLITE_UTF16_ALIGNED] if the +** the routine expects pointers to 16-bit word aligned strings +** of UTF-16 in the native byte order. +** +** A pointer to the user supplied routine must be passed as the fifth +** argument. If it is NULL, this is the same as deleting the collation +** sequence (so that SQLite cannot call it anymore). +** Each time the application supplied function is invoked, it is passed +** as its first parameter a copy of the void* passed as the fourth argument +** to sqlite3_create_collation() or sqlite3_create_collation16(). +** +** The remaining arguments to the application-supplied routine are two strings, +** each represented by a (length, data) pair and encoded in the encoding +** that was passed as the third argument when the collation sequence was +** registered. {END} The application defined collation routine should +** return negative, zero or positive if the first string is less than, +** equal to, or greater than the second string. i.e. (STRING1 - STRING2). +** +** The sqlite3_create_collation_v2() works like sqlite3_create_collation() +** except that it takes an extra argument which is a destructor for +** the collation. The destructor is called when the collation is +** destroyed and is passed a copy of the fourth parameter void* pointer +** of the sqlite3_create_collation_v2(). +** Collations are destroyed when they are overridden by later calls to the +** collation creation functions or when the [database connection] is closed +** using [sqlite3_close()]. +** +** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. +** +** Requirements: +** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] +** [H16624] [H16627] [H16630] +*/ +SQLITE_API int sqlite3_create_collation( + sqlite3*, + const char *zName, + int eTextRep, + void*, + int(*xCompare)(void*,int,const void*,int,const void*) +); +SQLITE_API int sqlite3_create_collation_v2( + sqlite3*, + const char *zName, + int eTextRep, + void*, + int(*xCompare)(void*,int,const void*,int,const void*), + void(*xDestroy)(void*) +); +SQLITE_API int sqlite3_create_collation16( + sqlite3*, + const void *zName, + int eTextRep, + void*, + int(*xCompare)(void*,int,const void*,int,const void*) +); + +/* +** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> +** +** To avoid having to register all collation sequences before a database +** can be used, a single callback function may be registered with the +** [database connection] to be called whenever an undefined collation +** sequence is required. +** +** If the function is registered using the sqlite3_collation_needed() API, +** then it is passed the names of undefined collation sequences as strings +** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, +** the names are passed as UTF-16 in machine native byte order. +** A call to either function replaces any existing callback. +** +** When the callback is invoked, the first argument passed is a copy +** of the second argument to sqlite3_collation_needed() or +** sqlite3_collation_needed16(). The second argument is the database +** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], +** or [SQLITE_UTF16LE], indicating the most desirable form of the collation +** sequence function required. The fourth parameter is the name of the +** required collation sequence. +** +** The callback function should register the desired collation using +** [sqlite3_create_collation()], [sqlite3_create_collation16()], or +** [sqlite3_create_collation_v2()]. +** +** Requirements: +** [H16702] [H16704] [H16706] +*/ +SQLITE_API int sqlite3_collation_needed( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const char*) +); +SQLITE_API int sqlite3_collation_needed16( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const void*) +); + +/* +** Specify the key for an encrypted database. This routine should be +** called right after sqlite3_open(). +** +** The code to implement this API is not available in the public release +** of SQLite. +*/ +SQLITE_API int sqlite3_key( + sqlite3 *db, /* Database to be rekeyed */ + const void *pKey, int nKey /* The key */ +); + +/* +** Change the key on an open database. If the current database is not +** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the +** database is decrypted. +** +** The code to implement this API is not available in the public release +** of SQLite. +*/ +SQLITE_API int sqlite3_rekey( + sqlite3 *db, /* Database to be rekeyed */ + const void *pKey, int nKey /* The new key */ +); + +/* +** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> +** +** The sqlite3_sleep() function causes the current thread to suspend execution +** for at least a number of milliseconds specified in its parameter. +** +** If the operating system does not support sleep requests with +** millisecond time resolution, then the time will be rounded up to +** the nearest second. The number of milliseconds of sleep actually +** requested from the operating system is returned. +** +** SQLite implements this interface by calling the xSleep() +** method of the default [sqlite3_vfs] object. +** +** Requirements: [H10533] [H10536] +*/ +SQLITE_API int sqlite3_sleep(int); + +/* +** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> +** +** If this global variable is made to point to a string which is +** the name of a folder (a.k.a. directory), then all temporary files +** created by SQLite will be placed in that directory. If this variable +** is a NULL pointer, then SQLite performs a search for an appropriate +** temporary file directory. +** +** It is not safe to read or modify this variable in more than one +** thread at a time. It is not safe to read or modify this variable +** if a [database connection] is being used at the same time in a separate +** thread. +** It is intended that this variable be set once +** as part of process initialization and before any SQLite interface +** routines have been called and that this variable remain unchanged +** thereafter. +** +** The [temp_store_directory pragma] may modify this variable and cause +** it to point to memory obtained from [sqlite3_malloc]. Furthermore, +** the [temp_store_directory pragma] always assumes that any string +** that this variable points to is held in memory obtained from +** [sqlite3_malloc] and the pragma may attempt to free that memory +** using [sqlite3_free]. +** Hence, if this variable is modified directly, either it should be +** made NULL or made to point to memory obtained from [sqlite3_malloc] +** or else the use of the [temp_store_directory pragma] should be avoided. +*/ +SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; + +/* +** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> +** KEYWORDS: {autocommit mode} +** +** The sqlite3_get_autocommit() interface returns non-zero or +** zero if the given database connection is or is not in autocommit mode, +** respectively. Autocommit mode is on by default. +** Autocommit mode is disabled by a [BEGIN] statement. +** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. +** +** If certain kinds of errors occur on a statement within a multi-statement +** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], +** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the +** transaction might be rolled back automatically. The only way to +** find out whether SQLite automatically rolled back the transaction after +** an error is to use this function. +** +** If another thread changes the autocommit status of the database +** connection while this routine is running, then the return value +** is undefined. +** +** Requirements: [H12931] [H12932] [H12933] [H12934] +*/ +SQLITE_API int sqlite3_get_autocommit(sqlite3*); + +/* +** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> +** +** The sqlite3_db_handle interface returns the [database connection] handle +** to which a [prepared statement] belongs. The [database connection] +** returned by sqlite3_db_handle is the same [database connection] that was the first argument +** to the [sqlite3_prepare_v2()] call (or its variants) that was used to +** create the statement in the first place. +** +** Requirements: [H13123] +*/ +SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); + +/* +** CAPI3REF: Find the next prepared statement {H13140} <S60600> +** +** This interface returns a pointer to the next [prepared statement] after +** pStmt associated with the [database connection] pDb. If pStmt is NULL +** then this interface returns a pointer to the first prepared statement +** associated with the database connection pDb. If no prepared statement +** satisfies the conditions of this routine, it returns NULL. +** +** The [database connection] pointer D in a call to +** [sqlite3_next_stmt(D,S)] must refer to an open database +** connection and in particular must not be a NULL pointer. +** +** Requirements: [H13143] [H13146] [H13149] [H13152] +*/ +SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> +** +** The sqlite3_commit_hook() interface registers a callback +** function to be invoked whenever a transaction is [COMMIT | committed]. +** Any callback set by a previous call to sqlite3_commit_hook() +** for the same database connection is overridden. +** The sqlite3_rollback_hook() interface registers a callback +** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. +** Any callback set by a previous call to sqlite3_commit_hook() +** for the same database connection is overridden. +** The pArg argument is passed through to the callback. +** If the callback on a commit hook function returns non-zero, +** then the commit is converted into a rollback. +** +** If another function was previously registered, its +** pArg value is returned. Otherwise NULL is returned. +** +** The callback implementation must not do anything that will modify +** the database connection that invoked the callback. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the commit +** or rollback hook in the first place. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** Registering a NULL function disables the callback. +** +** When the commit hook callback routine returns zero, the [COMMIT] +** operation is allowed to continue normally. If the commit hook +** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. +** The rollback hook is invoked on a rollback that results from a commit +** hook returning non-zero, just as it would be with any other rollback. +** +** For the purposes of this API, a transaction is said to have been +** rolled back if an explicit "ROLLBACK" statement is executed, or +** an error or constraint causes an implicit rollback to occur. +** The rollback callback is not invoked if a transaction is +** automatically rolled back because the database connection is closed. +** The rollback callback is not invoked if a transaction is +** rolled back because a commit callback returned non-zero. +** <todo> Check on this </todo> +** +** See also the [sqlite3_update_hook()] interface. +** +** Requirements: +** [H12951] [H12952] [H12953] [H12954] [H12955] +** [H12961] [H12962] [H12963] [H12964] +*/ +SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); +SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); + +/* +** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> +** +** The sqlite3_update_hook() interface registers a callback function +** with the [database connection] identified by the first argument +** to be invoked whenever a row is updated, inserted or deleted. +** Any callback set by a previous call to this function +** for the same database connection is overridden. +** +** The second argument is a pointer to the function to invoke when a +** row is updated, inserted or deleted. +** The first argument to the callback is a copy of the third argument +** to sqlite3_update_hook(). +** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], +** or [SQLITE_UPDATE], depending on the operation that caused the callback +** to be invoked. +** The third and fourth arguments to the callback contain pointers to the +** database and table name containing the affected row. +** The final callback parameter is the [rowid] of the row. +** In the case of an update, this is the [rowid] after the update takes place. +** +** The update hook is not invoked when internal system tables are +** modified (i.e. sqlite_master and sqlite_sequence). +** +** In the current implementation, the update hook +** is not invoked when duplication rows are deleted because of an +** [ON CONFLICT | ON CONFLICT REPLACE] clause. Nor is the update hook +** invoked when rows are deleted using the [truncate optimization]. +** The exceptions defined in this paragraph might change in a future +** release of SQLite. +** +** The update hook implementation must not do anything that will modify +** the database connection that invoked the update hook. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the update hook. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** If another function was previously registered, its pArg value +** is returned. Otherwise NULL is returned. +** +** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] +** interfaces. +** +** Requirements: +** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] +*/ +SQLITE_API void *sqlite3_update_hook( + sqlite3*, + void(*)(void *,int ,char const *,char const *,sqlite3_int64), + void* +); + +/* +** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> +** KEYWORDS: {shared cache} +** +** This routine enables or disables the sharing of the database cache +** and schema data structures between [database connection | connections] +** to the same database. Sharing is enabled if the argument is true +** and disabled if the argument is false. +** +** Cache sharing is enabled and disabled for an entire process. +** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, +** sharing was enabled or disabled for each thread separately. +** +** The cache sharing mode set by this interface effects all subsequent +** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. +** Existing database connections continue use the sharing mode +** that was in effect at the time they were opened. +** +** Virtual tables cannot be used with a shared cache. When shared +** cache is enabled, the [sqlite3_create_module()] API used to register +** virtual tables will always return an error. +** +** This routine returns [SQLITE_OK] if shared cache was enabled or disabled +** successfully. An [error code] is returned otherwise. +** +** Shared cache is disabled by default. But this might change in +** future releases of SQLite. Applications that care about shared +** cache setting should set it explicitly. +** +** See Also: [SQLite Shared-Cache Mode] +** +** Requirements: [H10331] [H10336] [H10337] [H10339] +*/ +SQLITE_API int sqlite3_enable_shared_cache(int); + +/* +** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> +** +** The sqlite3_release_memory() interface attempts to free N bytes +** of heap memory by deallocating non-essential memory allocations +** held by the database library. {END} Memory used to cache database +** pages to improve performance is an example of non-essential memory. +** sqlite3_release_memory() returns the number of bytes actually freed, +** which might be more or less than the amount requested. +** +** Requirements: [H17341] [H17342] +*/ +SQLITE_API int sqlite3_release_memory(int); + +/* +** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> +** +** The sqlite3_soft_heap_limit() interface places a "soft" limit +** on the amount of heap memory that may be allocated by SQLite. +** If an internal allocation is requested that would exceed the +** soft heap limit, [sqlite3_release_memory()] is invoked one or +** more times to free up some space before the allocation is performed. +** +** The limit is called "soft", because if [sqlite3_release_memory()] +** cannot free sufficient memory to prevent the limit from being exceeded, +** the memory is allocated anyway and the current operation proceeds. +** +** A negative or zero value for N means that there is no soft heap limit and +** [sqlite3_release_memory()] will only be called when memory is exhausted. +** The default value for the soft heap limit is zero. +** +** SQLite makes a best effort to honor the soft heap limit. +** But if the soft heap limit cannot be honored, execution will +** continue without error or notification. This is why the limit is +** called a "soft" limit. It is advisory only. +** +** Prior to SQLite version 3.5.0, this routine only constrained the memory +** allocated by a single thread - the same thread in which this routine +** runs. Beginning with SQLite version 3.5.0, the soft heap limit is +** applied to all threads. The value specified for the soft heap limit +** is an upper bound on the total memory allocation for all threads. In +** version 3.5.0 there is no mechanism for limiting the heap usage for +** individual threads. +** +** Requirements: +** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] +*/ +SQLITE_API void sqlite3_soft_heap_limit(int); + +/* +** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> +** +** This routine returns metadata about a specific column of a specific +** database table accessible using the [database connection] handle +** passed as the first function argument. +** +** The column is identified by the second, third and fourth parameters to +** this function. The second parameter is either the name of the database +** (i.e. "main", "temp" or an attached database) containing the specified +** table or NULL. If it is NULL, then all attached databases are searched +** for the table using the same algorithm used by the database engine to +** resolve unqualified table references. +** +** The third and fourth parameters to this function are the table and column +** name of the desired column, respectively. Neither of these parameters +** may be NULL. +** +** Metadata is returned by writing to the memory locations passed as the 5th +** and subsequent parameters to this function. Any of these arguments may be +** NULL, in which case the corresponding element of metadata is omitted. +** +** <blockquote> +** <table border="1"> +** <tr><th> Parameter <th> Output<br>Type <th> Description +** +** <tr><td> 5th <td> const char* <td> Data type +** <tr><td> 6th <td> const char* <td> Name of default collation sequence +** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint +** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY +** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] +** </table> +** </blockquote> +** +** The memory pointed to by the character pointers returned for the +** declaration type and collation sequence is valid only until the next +** call to any SQLite API function. +** +** If the specified table is actually a view, an [error code] is returned. +** +** If the specified column is "rowid", "oid" or "_rowid_" and an +** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output +** parameters are set for the explicitly declared column. If there is no +** explicitly declared [INTEGER PRIMARY KEY] column, then the output +** parameters are set as follows: +** +** <pre> +** data type: "INTEGER" +** collation sequence: "BINARY" +** not null: 0 +** primary key: 1 +** auto increment: 0 +** </pre> +** +** This function may load one or more schemas from database files. If an +** error occurs during this process, or if the requested table or column +** cannot be found, an [error code] is returned and an error message left +** in the [database connection] (to be retrieved using sqlite3_errmsg()). +** +** This API is only available if the library was compiled with the +** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. +*/ +SQLITE_API int sqlite3_table_column_metadata( + sqlite3 *db, /* Connection handle */ + const char *zDbName, /* Database name or NULL */ + const char *zTableName, /* Table name */ + const char *zColumnName, /* Column name */ + char const **pzDataType, /* OUTPUT: Declared data type */ + char const **pzCollSeq, /* OUTPUT: Collation sequence name */ + int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ + int *pPrimaryKey, /* OUTPUT: True if column part of PK */ + int *pAutoinc /* OUTPUT: True if column is auto-increment */ +); + +/* +** CAPI3REF: Load An Extension {H12600} <S20500> +** +** This interface loads an SQLite extension library from the named file. +** +** {H12601} The sqlite3_load_extension() interface attempts to load an +** SQLite extension library contained in the file zFile. +** +** {H12602} The entry point is zProc. +** +** {H12603} zProc may be 0, in which case the name of the entry point +** defaults to "sqlite3_extension_init". +** +** {H12604} The sqlite3_load_extension() interface shall return +** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. +** +** {H12605} If an error occurs and pzErrMsg is not 0, then the +** [sqlite3_load_extension()] interface shall attempt to +** fill *pzErrMsg with error message text stored in memory +** obtained from [sqlite3_malloc()]. {END} The calling function +** should free this memory by calling [sqlite3_free()]. +** +** {H12606} Extension loading must be enabled using +** [sqlite3_enable_load_extension()] prior to calling this API, +** otherwise an error will be returned. +*/ +SQLITE_API int sqlite3_load_extension( + sqlite3 *db, /* Load the extension into this database connection */ + const char *zFile, /* Name of the shared library containing extension */ + const char *zProc, /* Entry point. Derived from zFile if 0 */ + char **pzErrMsg /* Put error message here if not 0 */ +); + +/* +** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> +** +** So as not to open security holes in older applications that are +** unprepared to deal with extension loading, and as a means of disabling +** extension loading while evaluating user-entered SQL, the following API +** is provided to turn the [sqlite3_load_extension()] mechanism on and off. +** +** Extension loading is off by default. See ticket #1863. +** +** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 +** to turn extension loading on and call it with onoff==0 to turn +** it back off again. +** +** {H12622} Extension loading is off by default. +*/ +SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); + +/* +** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> +** +** This API can be invoked at program startup in order to register +** one or more statically linked extensions that will be available +** to all new [database connections]. {END} +** +** This routine stores a pointer to the extension in an array that is +** obtained from [sqlite3_malloc()]. If you run a memory leak checker +** on your program and it reports a leak because of this array, invoke +** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. +** +** {H12641} This function registers an extension entry point that is +** automatically invoked whenever a new [database connection] +** is opened using [sqlite3_open()], [sqlite3_open16()], +** or [sqlite3_open_v2()]. +** +** {H12642} Duplicate extensions are detected so calling this routine +** multiple times with the same extension is harmless. +** +** {H12643} This routine stores a pointer to the extension in an array +** that is obtained from [sqlite3_malloc()]. +** +** {H12644} Automatic extensions apply across all threads. +*/ +SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); + +/* +** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> +** +** This function disables all previously registered automatic +** extensions. {END} It undoes the effect of all prior +** [sqlite3_auto_extension()] calls. +** +** {H12661} This function disables all previously registered +** automatic extensions. +** +** {H12662} This function disables automatic extensions in all threads. +*/ +SQLITE_API void sqlite3_reset_auto_extension(void); + +/* +****** EXPERIMENTAL - subject to change without notice ************** +** +** The interface to the virtual-table mechanism is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +*/ + +/* +** Structures used by the virtual table interface +*/ +typedef struct sqlite3_vtab sqlite3_vtab; +typedef struct sqlite3_index_info sqlite3_index_info; +typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; +typedef struct sqlite3_module sqlite3_module; + +/* +** CAPI3REF: Virtual Table Object {H18000} <S20400> +** KEYWORDS: sqlite3_module {virtual table module} +** EXPERIMENTAL +** +** This structure, sometimes called a a "virtual table module", +** defines the implementation of a [virtual tables]. +** This structure consists mostly of methods for the module. +** +** A virtual table module is created by filling in a persistent +** instance of this structure and passing a pointer to that instance +** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. +** The registration remains valid until it is replaced by a different +** module or until the [database connection] closes. The content +** of this structure must not change while it is registered with +** any database connection. +*/ +struct sqlite3_module { + int iVersion; + int (*xCreate)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xConnect)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); + int (*xDisconnect)(sqlite3_vtab *pVTab); + int (*xDestroy)(sqlite3_vtab *pVTab); + int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); + int (*xClose)(sqlite3_vtab_cursor*); + int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, + int argc, sqlite3_value **argv); + int (*xNext)(sqlite3_vtab_cursor*); + int (*xEof)(sqlite3_vtab_cursor*); + int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); + int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); + int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); + int (*xBegin)(sqlite3_vtab *pVTab); + int (*xSync)(sqlite3_vtab *pVTab); + int (*xCommit)(sqlite3_vtab *pVTab); + int (*xRollback)(sqlite3_vtab *pVTab); + int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, + void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), + void **ppArg); + int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); +}; + +/* +** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> +** KEYWORDS: sqlite3_index_info +** EXPERIMENTAL +** +** The sqlite3_index_info structure and its substructures is used to +** pass information into and receive the reply from the [xBestIndex] +** method of a [virtual table module]. The fields under **Inputs** are the +** inputs to xBestIndex and are read-only. xBestIndex inserts its +** results into the **Outputs** fields. +** +** The aConstraint[] array records WHERE clause constraints of the form: +** +** <pre>column OP expr</pre> +** +** where OP is =, <, <=, >, or >=. The particular operator is +** stored in aConstraint[].op. The index of the column is stored in +** aConstraint[].iColumn. aConstraint[].usable is TRUE if the +** expr on the right-hand side can be evaluated (and thus the constraint +** is usable) and false if it cannot. +** +** The optimizer automatically inverts terms of the form "expr OP column" +** and makes other simplifications to the WHERE clause in an attempt to +** get as many WHERE clause terms into the form shown above as possible. +** The aConstraint[] array only reports WHERE clause terms in the correct +** form that refer to the particular virtual table being queried. +** +** Information about the ORDER BY clause is stored in aOrderBy[]. +** Each term of aOrderBy records a column of the ORDER BY clause. +** +** The [xBestIndex] method must fill aConstraintUsage[] with information +** about what parameters to pass to xFilter. If argvIndex>0 then +** the right-hand side of the corresponding aConstraint[] is evaluated +** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit +** is true, then the constraint is assumed to be fully handled by the +** virtual table and is not checked again by SQLite. +** +** The idxNum and idxPtr values are recorded and passed into the +** [xFilter] method. +** [sqlite3_free()] is used to free idxPtr if and only iff +** needToFreeIdxPtr is true. +** +** The orderByConsumed means that output from [xFilter]/[xNext] will occur in +** the correct order to satisfy the ORDER BY clause so that no separate +** sorting step is required. +** +** The estimatedCost value is an estimate of the cost of doing the +** particular lookup. A full scan of a table with N entries should have +** a cost of N. A binary search of a table of N entries should have a +** cost of approximately log(N). +*/ +struct sqlite3_index_info { + /* Inputs */ + int nConstraint; /* Number of entries in aConstraint */ + struct sqlite3_index_constraint { + int iColumn; /* Column on left-hand side of constraint */ + unsigned char op; /* Constraint operator */ + unsigned char usable; /* True if this constraint is usable */ + int iTermOffset; /* Used internally - xBestIndex should ignore */ + } *aConstraint; /* Table of WHERE clause constraints */ + int nOrderBy; /* Number of terms in the ORDER BY clause */ + struct sqlite3_index_orderby { + int iColumn; /* Column number */ + unsigned char desc; /* True for DESC. False for ASC. */ + } *aOrderBy; /* The ORDER BY clause */ + /* Outputs */ + struct sqlite3_index_constraint_usage { + int argvIndex; /* if >0, constraint is part of argv to xFilter */ + unsigned char omit; /* Do not code a test for this constraint */ + } *aConstraintUsage; + int idxNum; /* Number used to identify the index */ + char *idxStr; /* String, possibly obtained from sqlite3_malloc */ + int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ + int orderByConsumed; /* True if output is already ordered */ + double estimatedCost; /* Estimated cost of using this index */ +}; +#define SQLITE_INDEX_CONSTRAINT_EQ 2 +#define SQLITE_INDEX_CONSTRAINT_GT 4 +#define SQLITE_INDEX_CONSTRAINT_LE 8 +#define SQLITE_INDEX_CONSTRAINT_LT 16 +#define SQLITE_INDEX_CONSTRAINT_GE 32 +#define SQLITE_INDEX_CONSTRAINT_MATCH 64 + +/* +** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> +** EXPERIMENTAL +** +** This routine is used to register a new [virtual table module] name. +** Module names must be registered before +** creating a new [virtual table] using the module, or before using a +** preexisting [virtual table] for the module. +** +** The module name is registered on the [database connection] specified +** by the first parameter. The name of the module is given by the +** second parameter. The third parameter is a pointer to +** the implementation of the [virtual table module]. The fourth +** parameter is an arbitrary client data pointer that is passed through +** into the [xCreate] and [xConnect] methods of the virtual table module +** when a new virtual table is be being created or reinitialized. +** +** This interface has exactly the same effect as calling +** [sqlite3_create_module_v2()] with a NULL client data destructor. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_create_module( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData /* Client data for xCreate/xConnect */ +); + +/* +** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> +** EXPERIMENTAL +** +** This routine is identical to the [sqlite3_create_module()] method, +** except that it has an extra parameter to specify +** a destructor function for the client data pointer. SQLite will +** invoke the destructor function (if it is not NULL) when SQLite +** no longer needs the pClientData pointer. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData, /* Client data for xCreate/xConnect */ + void(*xDestroy)(void*) /* Module destructor function */ +); + +/* +** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> +** KEYWORDS: sqlite3_vtab +** EXPERIMENTAL +** +** Every [virtual table module] implementation uses a subclass +** of the following structure to describe a particular instance +** of the [virtual table]. Each subclass will +** be tailored to the specific needs of the module implementation. +** The purpose of this superclass is to define certain fields that are +** common to all module implementations. +** +** Virtual tables methods can set an error message by assigning a +** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should +** take care that any prior string is freed by a call to [sqlite3_free()] +** prior to assigning a new string to zErrMsg. After the error message +** is delivered up to the client application, the string will be automatically +** freed by sqlite3_free() and the zErrMsg field will be zeroed. +*/ +struct sqlite3_vtab { + const sqlite3_module *pModule; /* The module for this virtual table */ + int nRef; /* NO LONGER USED */ + char *zErrMsg; /* Error message from sqlite3_mprintf() */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> +** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} +** EXPERIMENTAL +** +** Every [virtual table module] implementation uses a subclass of the +** following structure to describe cursors that point into the +** [virtual table] and are used +** to loop through the virtual table. Cursors are created using the +** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed +** by the [sqlite3_module.xClose | xClose] method. Cussors are used +** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods +** of the module. Each module implementation will define +** the content of a cursor structure to suit its own needs. +** +** This superclass exists in order to define fields of the cursor that +** are common to all implementations. +*/ +struct sqlite3_vtab_cursor { + sqlite3_vtab *pVtab; /* Virtual table of this cursor */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> +** EXPERIMENTAL +** +** The [xCreate] and [xConnect] methods of a +** [virtual table module] call this interface +** to declare the format (the names and datatypes of the columns) of +** the virtual tables they implement. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL); + +/* +** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> +** EXPERIMENTAL +** +** Virtual tables can provide alternative implementations of functions +** using the [xFindFunction] method of the [virtual table module]. +** But global versions of those functions +** must exist in order to be overloaded. +** +** This API makes sure a global version of a function with a particular +** name and number of parameters exists. If no such function exists +** before this API is called, a new function is created. The implementation +** of the new function always causes an exception to be thrown. So +** the new function is not good for anything by itself. Its only +** purpose is to be a placeholder function that can be overloaded +** by a [virtual table]. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); + +/* +** The interface to the virtual-table mechanism defined above (back up +** to a comment remarkably similar to this one) is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +** +****** EXPERIMENTAL - subject to change without notice ************** +*/ + +/* +** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> +** KEYWORDS: {BLOB handle} {BLOB handles} +** +** An instance of this object represents an open BLOB on which +** [sqlite3_blob_open | incremental BLOB I/O] can be performed. +** Objects of this type are created by [sqlite3_blob_open()] +** and destroyed by [sqlite3_blob_close()]. +** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces +** can be used to read or write small subsections of the BLOB. +** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. +*/ +typedef struct sqlite3_blob sqlite3_blob; + +/* +** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> +** +** This interfaces opens a [BLOB handle | handle] to the BLOB located +** in row iRow, column zColumn, table zTable in database zDb; +** in other words, the same BLOB that would be selected by: +** +** <pre> +** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; +** </pre> {END} +** +** If the flags parameter is non-zero, then the BLOB is opened for read +** and write access. If it is zero, the BLOB is opened for read access. +** It is not possible to open a column that is part of an index or primary +** key for writing. ^If [foreign key constraints] are enabled, it is +** not possible to open a column that is part of a [child key] for writing. +** +** Note that the database name is not the filename that contains +** the database but rather the symbolic name of the database that +** is assigned when the database is connected using [ATTACH]. +** For the main database file, the database name is "main". +** For TEMP tables, the database name is "temp". +** +** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written +** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set +** to be a null pointer. +** This function sets the [database connection] error code and message +** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related +** functions. Note that the *ppBlob variable is always initialized in a +** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob +** regardless of the success or failure of this routine. +** +** If the row that a BLOB handle points to is modified by an +** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects +** then the BLOB handle is marked as "expired". +** This is true if any column of the row is changed, even a column +** other than the one the BLOB handle is open on. +** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for +** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. +** Changes written into a BLOB prior to the BLOB expiring are not +** rollback by the expiration of the BLOB. Such changes will eventually +** commit if the transaction continues to completion. +** +** Use the [sqlite3_blob_bytes()] interface to determine the size of +** the opened blob. The size of a blob may not be changed by this +** interface. Use the [UPDATE] SQL command to change the size of a +** blob. +** +** The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces +** and the built-in [zeroblob] SQL function can be used, if desired, +** to create an empty, zero-filled blob in which to read or write using +** this interface. +** +** To avoid a resource leak, every open [BLOB handle] should eventually +** be released by a call to [sqlite3_blob_close()]. +** +** Requirements: +** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] +*/ +SQLITE_API int sqlite3_blob_open( + sqlite3*, + const char *zDb, + const char *zTable, + const char *zColumn, + sqlite3_int64 iRow, + int flags, + sqlite3_blob **ppBlob +); + +/* +** CAPI3REF: Close A BLOB Handle {H17830} <S30230> +** +** Closes an open [BLOB handle]. +** +** Closing a BLOB shall cause the current transaction to commit +** if there are no other BLOBs, no pending prepared statements, and the +** database connection is in [autocommit mode]. +** If any writes were made to the BLOB, they might be held in cache +** until the close operation if they will fit. +** +** Closing the BLOB often forces the changes +** out to disk and so if any I/O errors occur, they will likely occur +** at the time when the BLOB is closed. Any errors that occur during +** closing are reported as a non-zero return value. +** +** The BLOB is closed unconditionally. Even if this routine returns +** an error code, the BLOB is still closed. +** +** Calling this routine with a null pointer (which as would be returned +** by failed call to [sqlite3_blob_open()]) is a harmless no-op. +** +** Requirements: +** [H17833] [H17836] [H17839] +*/ +SQLITE_API int sqlite3_blob_close(sqlite3_blob *); + +/* +** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> +** +** Returns the size in bytes of the BLOB accessible via the +** successfully opened [BLOB handle] in its only argument. The +** incremental blob I/O routines can only read or overwriting existing +** blob content; they cannot change the size of a blob. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** Requirements: +** [H17843] +*/ +SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); + +/* +** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> +** +** This function is used to read data from an open [BLOB handle] into a +** caller-supplied buffer. N bytes of data are copied into buffer Z +** from the open BLOB, starting at offset iOffset. +** +** If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is +** less than zero, [SQLITE_ERROR] is returned and no data is read. +** The size of the blob (and hence the maximum value of N+iOffset) +** can be determined using the [sqlite3_blob_bytes()] interface. +** +** An attempt to read from an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. +** +** On success, SQLITE_OK is returned. +** Otherwise, an [error code] or an [extended error code] is returned. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_write()]. +** +** Requirements: +** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] +*/ +SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); + +/* +** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> +** +** This function is used to write data into an open [BLOB handle] from a +** caller-supplied buffer. N bytes of data are copied from the buffer Z +** into the open BLOB, starting at offset iOffset. +** +** If the [BLOB handle] passed as the first argument was not opened for +** writing (the flags parameter to [sqlite3_blob_open()] was zero), +** this function returns [SQLITE_READONLY]. +** +** This function may only modify the contents of the BLOB; it is +** not possible to increase the size of a BLOB using this API. +** If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is written. If N is +** less than zero [SQLITE_ERROR] is returned and no data is written. +** The size of the BLOB (and hence the maximum value of N+iOffset) +** can be determined using the [sqlite3_blob_bytes()] interface. +** +** An attempt to write to an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred +** before the [BLOB handle] expired are not rolled back by the +** expiration of the handle, though of course those changes might +** have been overwritten by the statement that expired the BLOB handle +** or by other independent statements. +** +** On success, SQLITE_OK is returned. +** Otherwise, an [error code] or an [extended error code] is returned. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_read()]. +** +** Requirements: +** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] +** [H17888] +*/ +SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); + +/* +** CAPI3REF: Virtual File System Objects {H11200} <S20100> +** +** A virtual filesystem (VFS) is an [sqlite3_vfs] object +** that SQLite uses to interact +** with the underlying operating system. Most SQLite builds come with a +** single default VFS that is appropriate for the host computer. +** New VFSes can be registered and existing VFSes can be unregistered. +** The following interfaces are provided. +** +** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. +** Names are case sensitive. +** Names are zero-terminated UTF-8 strings. +** If there is no match, a NULL pointer is returned. +** If zVfsName is NULL then the default VFS is returned. +** +** New VFSes are registered with sqlite3_vfs_register(). +** Each new VFS becomes the default VFS if the makeDflt flag is set. +** The same VFS can be registered multiple times without injury. +** To make an existing VFS into the default VFS, register it again +** with the makeDflt flag set. If two different VFSes with the +** same name are registered, the behavior is undefined. If a +** VFS is registered with a name that is NULL or an empty string, +** then the behavior is undefined. +** +** Unregister a VFS with the sqlite3_vfs_unregister() interface. +** If the default VFS is unregistered, another VFS is chosen as +** the default. The choice for the new VFS is arbitrary. +** +** Requirements: +** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] +*/ +SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); +SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); +SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); + +/* +** CAPI3REF: Mutexes {H17000} <S20000> +** +** The SQLite core uses these routines for thread +** synchronization. Though they are intended for internal +** use by SQLite, code that links against SQLite is +** permitted to use any of these routines. +** +** The SQLite source code contains multiple implementations +** of these mutex routines. An appropriate implementation +** is selected automatically at compile-time. The following +** implementations are available in the SQLite core: +** +** <ul> +** <li> SQLITE_MUTEX_OS2 +** <li> SQLITE_MUTEX_PTHREAD +** <li> SQLITE_MUTEX_W32 +** <li> SQLITE_MUTEX_NOOP +** </ul> +** +** The SQLITE_MUTEX_NOOP implementation is a set of routines +** that does no real locking and is appropriate for use in +** a single-threaded application. The SQLITE_MUTEX_OS2, +** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations +** are appropriate for use on OS/2, Unix, and Windows. +** +** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor +** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex +** implementation is included with the library. In this case the +** application must supply a custom mutex implementation using the +** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function +** before calling sqlite3_initialize() or any other public sqlite3_ +** function that calls sqlite3_initialize(). +** +** {H17011} The sqlite3_mutex_alloc() routine allocates a new +** mutex and returns a pointer to it. {H17012} If it returns NULL +** that means that a mutex could not be allocated. {H17013} SQLite +** will unwind its stack and return an error. {H17014} The argument +** to sqlite3_mutex_alloc() is one of these integer constants: +** +** <ul> +** <li> SQLITE_MUTEX_FAST +** <li> SQLITE_MUTEX_RECURSIVE +** <li> SQLITE_MUTEX_STATIC_MASTER +** <li> SQLITE_MUTEX_STATIC_MEM +** <li> SQLITE_MUTEX_STATIC_MEM2 +** <li> SQLITE_MUTEX_STATIC_PRNG +** <li> SQLITE_MUTEX_STATIC_LRU +** <li> SQLITE_MUTEX_STATIC_LRU2 +** </ul> +** +** {H17015} The first two constants cause sqlite3_mutex_alloc() to create +** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE +** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} +** The mutex implementation does not need to make a distinction +** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does +** not want to. {H17016} But SQLite will only request a recursive mutex in +** cases where it really needs one. {END} If a faster non-recursive mutex +** implementation is available on the host platform, the mutex subsystem +** might return such a mutex in response to SQLITE_MUTEX_FAST. +** +** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return +** a pointer to a static preexisting mutex. {END} Six static mutexes are +** used by the current version of SQLite. Future versions of SQLite +** may add additional static mutexes. Static mutexes are for internal +** use by SQLite only. Applications that use SQLite mutexes should +** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or +** SQLITE_MUTEX_RECURSIVE. +** +** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST +** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() +** returns a different mutex on every call. {H17034} But for the static +** mutex types, the same mutex is returned on every call that has +** the same type number. +** +** {H17019} The sqlite3_mutex_free() routine deallocates a previously +** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every +** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in +** use when they are deallocated. {A17022} Attempting to deallocate a static +** mutex results in undefined behavior. {H17023} SQLite never deallocates +** a static mutex. {END} +** +** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt +** to enter a mutex. {H17024} If another thread is already within the mutex, +** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return +** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] +** upon successful entry. {H17026} Mutexes created using +** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. +** {H17027} In such cases the, +** mutex must be exited an equal number of times before another thread +** can enter. {A17028} If the same thread tries to enter any other +** kind of mutex more than once, the behavior is undefined. +** {H17029} SQLite will never exhibit +** such behavior in its own use of mutexes. +** +** Some systems (for example, Windows 95) do not support the operation +** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() +** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses +** sqlite3_mutex_try() as an optimization so this is acceptable behavior. +** +** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was +** previously entered by the same thread. {A17032} The behavior +** is undefined if the mutex is not currently entered by the +** calling thread or is not currently allocated. {H17033} SQLite will +** never do either. {END} +** +** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or +** sqlite3_mutex_leave() is a NULL pointer, then all three routines +** behave as no-ops. +** +** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. +*/ +SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); +SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); +SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); +SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); +SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); + +/* +** CAPI3REF: Mutex Methods Object {H17120} <S20130> +** EXPERIMENTAL +** +** An instance of this structure defines the low-level routines +** used to allocate and use mutexes. +** +** Usually, the default mutex implementations provided by SQLite are +** sufficient, however the user has the option of substituting a custom +** implementation for specialized deployments or systems for which SQLite +** does not provide a suitable implementation. In this case, the user +** creates and populates an instance of this structure to pass +** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. +** Additionally, an instance of this structure can be used as an +** output variable when querying the system for the current mutex +** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. +** +** The xMutexInit method defined by this structure is invoked as +** part of system initialization by the sqlite3_initialize() function. +** {H17001} The xMutexInit routine shall be called by SQLite once for each +** effective call to [sqlite3_initialize()]. +** +** The xMutexEnd method defined by this structure is invoked as +** part of system shutdown by the sqlite3_shutdown() function. The +** implementation of this method is expected to release all outstanding +** resources obtained by the mutex methods implementation, especially +** those obtained by the xMutexInit method. {H17003} The xMutexEnd() +** interface shall be invoked once for each call to [sqlite3_shutdown()]. +** +** The remaining seven methods defined by this structure (xMutexAlloc, +** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and +** xMutexNotheld) implement the following interfaces (respectively): +** +** <ul> +** <li> [sqlite3_mutex_alloc()] </li> +** <li> [sqlite3_mutex_free()] </li> +** <li> [sqlite3_mutex_enter()] </li> +** <li> [sqlite3_mutex_try()] </li> +** <li> [sqlite3_mutex_leave()] </li> +** <li> [sqlite3_mutex_held()] </li> +** <li> [sqlite3_mutex_notheld()] </li> +** </ul> +** +** The only difference is that the public sqlite3_XXX functions enumerated +** above silently ignore any invocations that pass a NULL pointer instead +** of a valid mutex handle. The implementations of the methods defined +** by this structure are not required to handle this case, the results +** of passing a NULL pointer instead of a valid mutex handle are undefined +** (i.e. it is acceptable to provide an implementation that segfaults if +** it is passed a NULL pointer). +** +** The xMutexInit() method must be threadsafe. It must be harmless to +** invoke xMutexInit() mutiple times within the same process and without +** intervening calls to xMutexEnd(). Second and subsequent calls to +** xMutexInit() must be no-ops. +** +** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] +** and its associates). Similarly, xMutexAlloc() must not use SQLite memory +** allocation for a static mutex. However xMutexAlloc() may use SQLite +** memory allocation for a fast or recursive mutex. +** +** SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is +** called, but only if the prior call to xMutexInit returned SQLITE_OK. +** If xMutexInit fails in any way, it is expected to clean up after itself +** prior to returning. +*/ +typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; +struct sqlite3_mutex_methods { + int (*xMutexInit)(void); + int (*xMutexEnd)(void); + sqlite3_mutex *(*xMutexAlloc)(int); + void (*xMutexFree)(sqlite3_mutex *); + void (*xMutexEnter)(sqlite3_mutex *); + int (*xMutexTry)(sqlite3_mutex *); + void (*xMutexLeave)(sqlite3_mutex *); + int (*xMutexHeld)(sqlite3_mutex *); + int (*xMutexNotheld)(sqlite3_mutex *); +}; + +/* +** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> +** +** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines +** are intended for use inside assert() statements. {H17081} The SQLite core +** never uses these routines except inside an assert() and applications +** are advised to follow the lead of the core. {H17082} The core only +** provides implementations for these routines when it is compiled +** with the SQLITE_DEBUG flag. {A17087} External mutex implementations +** are only required to provide these routines if SQLITE_DEBUG is +** defined and if NDEBUG is not defined. +** +** {H17083} These routines should return true if the mutex in their argument +** is held or not held, respectively, by the calling thread. +** +** {X17084} The implementation is not required to provided versions of these +** routines that actually work. If the implementation does not provide working +** versions of these routines, it should at least provide stubs that always +** return true so that one does not get spurious assertion failures. +** +** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then +** the routine should return 1. {END} This seems counter-intuitive since +** clearly the mutex cannot be held if it does not exist. But the +** the reason the mutex does not exist is because the build is not +** using mutexes. And we do not want the assert() containing the +** call to sqlite3_mutex_held() to fail, so a non-zero return is +** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() +** interface should also return 1 when given a NULL pointer. +*/ +SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); +SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); + +/* +** CAPI3REF: Mutex Types {H17001} <H17000> +** +** The [sqlite3_mutex_alloc()] interface takes a single argument +** which is one of these integer constants. +** +** The set of static mutexes may change from one SQLite release to the +** next. Applications that override the built-in mutex logic must be +** prepared to accommodate additional static mutexes. +*/ +#define SQLITE_MUTEX_FAST 0 +#define SQLITE_MUTEX_RECURSIVE 1 +#define SQLITE_MUTEX_STATIC_MASTER 2 +#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ +#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ +#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ +#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ +#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ + +/* +** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> +** +** This interface returns a pointer the [sqlite3_mutex] object that +** serializes access to the [database connection] given in the argument +** when the [threading mode] is Serialized. +** If the [threading mode] is Single-thread or Multi-thread then this +** routine returns a NULL pointer. +*/ +SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); + +/* +** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> +** +** {H11301} The [sqlite3_file_control()] interface makes a direct call to the +** xFileControl method for the [sqlite3_io_methods] object associated +** with a particular database identified by the second argument. {H11302} The +** name of the database is the name assigned to the database by the +** <a href="lang_attach.html">ATTACH</a> SQL command that opened the +** database. {H11303} To control the main database file, use the name "main" +** or a NULL pointer. {H11304} The third and fourth parameters to this routine +** are passed directly through to the second and third parameters of +** the xFileControl method. {H11305} The return value of the xFileControl +** method becomes the return value of this routine. +** +** {H11306} If the second parameter (zDbName) does not match the name of any +** open database file, then SQLITE_ERROR is returned. {H11307} This error +** code is not remembered and will not be recalled by [sqlite3_errcode()] +** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might +** also return SQLITE_ERROR. {A11309} There is no way to distinguish between +** an incorrect zDbName and an SQLITE_ERROR return from the underlying +** xFileControl method. {END} +** +** See also: [SQLITE_FCNTL_LOCKSTATE] +*/ +SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); + +/* +** CAPI3REF: Testing Interface {H11400} <S30800> +** +** The sqlite3_test_control() interface is used to read out internal +** state of SQLite and to inject faults into SQLite for testing +** purposes. The first parameter is an operation code that determines +** the number, meaning, and operation of all subsequent parameters. +** +** This interface is not for use by applications. It exists solely +** for verifying the correct operation of the SQLite library. Depending +** on how the SQLite library is compiled, this interface might not exist. +** +** The details of the operation codes, their meanings, the parameters +** they take, and what they do are all subject to change without notice. +** Unlike most of the SQLite API, this function is not guaranteed to +** operate consistently from one release to the next. +*/ +SQLITE_API int sqlite3_test_control(int op, ...); + +/* +** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> +** +** These constants are the valid operation code parameters used +** as the first argument to [sqlite3_test_control()]. +** +** These parameters and their meanings are subject to change +** without notice. These values are for testing purposes only. +** Applications should not use any of these parameters or the +** [sqlite3_test_control()] interface. +*/ +#define SQLITE_TESTCTRL_PRNG_SAVE 5 +#define SQLITE_TESTCTRL_PRNG_RESTORE 6 +#define SQLITE_TESTCTRL_PRNG_RESET 7 +#define SQLITE_TESTCTRL_BITVEC_TEST 8 +#define SQLITE_TESTCTRL_FAULT_INSTALL 9 +#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 +#define SQLITE_TESTCTRL_PENDING_BYTE 11 +#define SQLITE_TESTCTRL_ASSERT 12 +#define SQLITE_TESTCTRL_ALWAYS 13 +#define SQLITE_TESTCTRL_RESERVE 14 + +/* +** CAPI3REF: SQLite Runtime Status {H17200} <S60200> +** EXPERIMENTAL +** +** This interface is used to retrieve runtime status information +** about the preformance of SQLite, and optionally to reset various +** highwater marks. The first argument is an integer code for +** the specific parameter to measure. Recognized integer codes +** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. +** The current value of the parameter is returned into *pCurrent. +** The highest recorded value is returned in *pHighwater. If the +** resetFlag is true, then the highest record value is reset after +** *pHighwater is written. Some parameters do not record the highest +** value. For those parameters +** nothing is written into *pHighwater and the resetFlag is ignored. +** Other parameters record only the highwater mark and not the current +** value. For these latter parameters nothing is written into *pCurrent. +** +** This routine returns SQLITE_OK on success and a non-zero +** [error code] on failure. +** +** This routine is threadsafe but is not atomic. This routine can be +** called while other threads are running the same or different SQLite +** interfaces. However the values returned in *pCurrent and +** *pHighwater reflect the status of SQLite at different points in time +** and it is possible that another thread might change the parameter +** in between the times when *pCurrent and *pHighwater are written. +** +** See also: [sqlite3_db_status()] +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); + + +/* +** CAPI3REF: Status Parameters {H17250} <H17200> +** EXPERIMENTAL +** +** These integer constants designate various run-time status parameters +** that can be returned by [sqlite3_status()]. +** +** <dl> +** <dt>SQLITE_STATUS_MEMORY_USED</dt> +** <dd>This parameter is the current amount of memory checked out +** using [sqlite3_malloc()], either directly or indirectly. The +** figure includes calls made to [sqlite3_malloc()] by the application +** and internal memory usage by the SQLite library. Scratch memory +** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache +** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in +** this parameter. The amount returned is the sum of the allocation +** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> +** +** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their +** internal equivalents). Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd> +** +** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> +** <dd>This parameter returns the number of pages used out of the +** [pagecache memory allocator] that was configured using +** [SQLITE_CONFIG_PAGECACHE]. The +** value returned is in pages, not in bytes.</dd> +** +** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> +** <dd>This parameter returns the number of bytes of page cache +** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] +** buffer and where forced to overflow to [sqlite3_malloc()]. The +** returned value includes allocations that overflowed because they +** where too large (they were larger than the "sz" parameter to +** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because +** no space was left in the page cache.</dd> +** +** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [pagecache memory allocator]. Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd> +** +** <dt>SQLITE_STATUS_SCRATCH_USED</dt> +** <dd>This parameter returns the number of allocations used out of the +** [scratch memory allocator] configured using +** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not +** in bytes. Since a single thread may only have one scratch allocation +** outstanding at time, this parameter also reports the number of threads +** using scratch memory at the same time.</dd> +** +** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> +** <dd>This parameter returns the number of bytes of scratch memory +** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] +** buffer and where forced to overflow to [sqlite3_malloc()]. The values +** returned include overflows because the requested allocation was too +** larger (that is, because the requested allocation was larger than the +** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer +** slots were available. +** </dd> +** +** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [scratch memory allocator]. Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd> +** +** <dt>SQLITE_STATUS_PARSER_STACK</dt> +** <dd>This parameter records the deepest parser stack. It is only +** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> +** </dl> +** +** New status parameters may be added from time to time. +*/ +#define SQLITE_STATUS_MEMORY_USED 0 +#define SQLITE_STATUS_PAGECACHE_USED 1 +#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 +#define SQLITE_STATUS_SCRATCH_USED 3 +#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 +#define SQLITE_STATUS_MALLOC_SIZE 5 +#define SQLITE_STATUS_PARSER_STACK 6 +#define SQLITE_STATUS_PAGECACHE_SIZE 7 +#define SQLITE_STATUS_SCRATCH_SIZE 8 + +/* +** CAPI3REF: Database Connection Status {H17500} <S60200> +** EXPERIMENTAL +** +** This interface is used to retrieve runtime status information +** about a single [database connection]. The first argument is the +** database connection object to be interrogated. The second argument +** is the parameter to interrogate. Currently, the only allowed value +** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. +** Additional options will likely appear in future releases of SQLite. +** +** The current value of the requested parameter is written into *pCur +** and the highest instantaneous value is written into *pHiwtr. If +** the resetFlg is true, then the highest instantaneous value is +** reset back down to the current value. +** +** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); + +/* +** CAPI3REF: Status Parameters for database connections {H17520} <H17500> +** EXPERIMENTAL +** +** These constants are the available integer "verbs" that can be passed as +** the second argument to the [sqlite3_db_status()] interface. +** +** New verbs may be added in future releases of SQLite. Existing verbs +** might be discontinued. Applications should check the return code from +** [sqlite3_db_status()] to make sure that the call worked. +** The [sqlite3_db_status()] interface will return a non-zero error code +** if a discontinued or unsupported verb is invoked. +** +** <dl> +** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> +** <dd>This parameter returns the number of lookaside memory slots currently +** checked out.</dd> +** </dl> +*/ +#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 + + +/* +** CAPI3REF: Prepared Statement Status {H17550} <S60200> +** EXPERIMENTAL +** +** Each prepared statement maintains various +** [SQLITE_STMTSTATUS_SORT | counters] that measure the number +** of times it has performed specific operations. These counters can +** be used to monitor the performance characteristics of the prepared +** statements. For example, if the number of table steps greatly exceeds +** the number of table searches or result rows, that would tend to indicate +** that the prepared statement is using a full table scan rather than +** an index. +** +** This interface is used to retrieve and reset counter values from +** a [prepared statement]. The first argument is the prepared statement +** object to be interrogated. The second argument +** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] +** to be interrogated. +** The current value of the requested counter is returned. +** If the resetFlg is true, then the counter is reset to zero after this +** interface call returns. +** +** See also: [sqlite3_status()] and [sqlite3_db_status()]. +*/ +SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); + +/* +** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> +** EXPERIMENTAL +** +** These preprocessor macros define integer codes that name counter +** values associated with the [sqlite3_stmt_status()] interface. +** The meanings of the various counters are as follows: +** +** <dl> +** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> +** <dd>This is the number of times that SQLite has stepped forward in +** a table as part of a full table scan. Large numbers for this counter +** may indicate opportunities for performance improvement through +** careful use of indices.</dd> +** +** <dt>SQLITE_STMTSTATUS_SORT</dt> +** <dd>This is the number of sort operations that have occurred. +** A non-zero value in this counter may indicate an opportunity to +** improvement performance through careful use of indices.</dd> +** +** </dl> +*/ +#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 +#define SQLITE_STMTSTATUS_SORT 2 + +/* +** CAPI3REF: Custom Page Cache Object +** EXPERIMENTAL +** +** The sqlite3_pcache type is opaque. It is implemented by +** the pluggable module. The SQLite core has no knowledge of +** its size or internal structure and never deals with the +** sqlite3_pcache object except by holding and passing pointers +** to the object. +** +** See [sqlite3_pcache_methods] for additional information. +*/ +typedef struct sqlite3_pcache sqlite3_pcache; + +/* +** CAPI3REF: Application Defined Page Cache. +** KEYWORDS: {page cache} +** EXPERIMENTAL +** +** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can +** register an alternative page cache implementation by passing in an +** instance of the sqlite3_pcache_methods structure. The majority of the +** heap memory used by SQLite is used by the page cache to cache data read +** from, or ready to be written to, the database file. By implementing a +** custom page cache using this API, an application can control more +** precisely the amount of memory consumed by SQLite, the way in which +** that memory is allocated and released, and the policies used to +** determine exactly which parts of a database file are cached and for +** how long. +** +** The contents of the sqlite3_pcache_methods structure are copied to an +** internal buffer by SQLite within the call to [sqlite3_config]. Hence +** the application may discard the parameter after the call to +** [sqlite3_config()] returns. +** +** The xInit() method is called once for each call to [sqlite3_initialize()] +** (usually only once during the lifetime of the process). It is passed +** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set +** up global structures and mutexes required by the custom page cache +** implementation. +** +** The xShutdown() method is called from within [sqlite3_shutdown()], +** if the application invokes this API. It can be used to clean up +** any outstanding resources before process shutdown, if required. +** +** SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes +** the xInit method, so the xInit method need not be threadsafe. The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. All other methods must be threadsafe +** in multithreaded applications. +** +** SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +** +** The xCreate() method is used to construct a new cache instance. SQLite +** will typically create one cache instance for each open database file, +** though this is not guaranteed. The +** first parameter, szPage, is the size in bytes of the pages that must +** be allocated by the cache. szPage will not be a power of two. szPage +** will the page size of the database file that is to be cached plus an +** increment (here called "R") of about 100 or 200. SQLite will use the +** extra R bytes on each page to store metadata about the underlying +** database page on disk. The value of R depends +** on the SQLite version, the target platform, and how SQLite was compiled. +** R is constant for a particular build of SQLite. The second argument to +** xCreate(), bPurgeable, is true if the cache being created will +** be used to cache database pages of a file stored on disk, or +** false if it is used for an in-memory database. The cache implementation +** does not have to do anything special based with the value of bPurgeable; +** it is purely advisory. On a cache where bPurgeable is false, SQLite will +** never invoke xUnpin() except to deliberately delete a page. +** In other words, a cache created with bPurgeable set to false will +** never contain any unpinned pages. +** +** The xCachesize() method may be called at any time by SQLite to set the +** suggested maximum cache-size (number of pages stored by) the cache +** instance passed as the first argument. This is the value configured using +** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, +** the implementation is not required to do anything with this +** value; it is advisory only. +** +** The xPagecount() method should return the number of pages currently +** stored in the cache. +** +** The xFetch() method is used to fetch a page and return a pointer to it. +** A 'page', in this context, is a buffer of szPage bytes aligned at an +** 8-byte boundary. The page to be fetched is determined by the key. The +** mimimum key value is 1. After it has been retrieved using xFetch, the page +** is considered to be "pinned". +** +** If the requested page is already in the page cache, then the page cache +** implementation must return a pointer to the page buffer with its content +** intact. If the requested page is not already in the cache, then the +** behavior of the cache implementation is determined by the value of the +** createFlag parameter passed to xFetch, according to the following table: +** +** <table border=1 width=85% align=center> +** <tr><th> createFlag <th> Behaviour when page is not already in cache +** <tr><td> 0 <td> Do not allocate a new page. Return NULL. +** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. +** Otherwise return NULL. +** <tr><td> 2 <td> Make every effort to allocate a new page. Only return +** NULL if allocating a new page is effectively impossible. +** </table> +** +** SQLite will normally invoke xFetch() with a createFlag of 0 or 1. If +** a call to xFetch() with createFlag==1 returns NULL, then SQLite will +** attempt to unpin one or more cache pages by spilling the content of +** pinned pages to disk and synching the operating system disk cache. After +** attempting to unpin pages, the xFetch() method will be invoked again with +** a createFlag of 2. +** +** xUnpin() is called by SQLite with a pointer to a currently pinned page +** as its second argument. If the third parameter, discard, is non-zero, +** then the page should be evicted from the cache. In this case SQLite +** assumes that the next time the page is retrieved from the cache using +** the xFetch() method, it will be zeroed. If the discard parameter is +** zero, then the page is considered to be unpinned. The cache implementation +** may choose to evict unpinned pages at any time. +** +** The cache is not required to perform any reference counting. A single +** call to xUnpin() unpins the page regardless of the number of prior calls +** to xFetch(). +** +** The xRekey() method is used to change the key value associated with the +** page passed as the second argument from oldKey to newKey. If the cache +** previously contains an entry associated with newKey, it should be +** discarded. Any prior cache entry associated with newKey is guaranteed not +** to be pinned. +** +** When SQLite calls the xTruncate() method, the cache must discard all +** existing cache entries with page numbers (keys) greater than or equal +** to the value of the iLimit parameter passed to xTruncate(). If any +** of these pages are pinned, they are implicitly unpinned, meaning that +** they can be safely discarded. +** +** The xDestroy() method is used to delete a cache allocated by xCreate(). +** All resources associated with the specified cache should be freed. After +** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] +** handle invalid, and will not use it with any other sqlite3_pcache_methods +** functions. +*/ +typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; +struct sqlite3_pcache_methods { + void *pArg; + int (*xInit)(void*); + void (*xShutdown)(void*); + sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); + void (*xCachesize)(sqlite3_pcache*, int nCachesize); + int (*xPagecount)(sqlite3_pcache*); + void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); + void (*xUnpin)(sqlite3_pcache*, void*, int discard); + void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); + void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); + void (*xDestroy)(sqlite3_pcache*); +}; + +/* +** CAPI3REF: Online Backup Object +** EXPERIMENTAL +** +** The sqlite3_backup object records state information about an ongoing +** online backup operation. The sqlite3_backup object is created by +** a call to [sqlite3_backup_init()] and is destroyed by a call to +** [sqlite3_backup_finish()]. +** +** See Also: [Using the SQLite Online Backup API] +*/ +typedef struct sqlite3_backup sqlite3_backup; + +/* +** CAPI3REF: Online Backup API. +** EXPERIMENTAL +** +** This API is used to overwrite the contents of one database with that +** of another. It is useful either for creating backups of databases or +** for copying in-memory databases to or from persistent files. +** +** See Also: [Using the SQLite Online Backup API] +** +** Exclusive access is required to the destination database for the +** duration of the operation. However the source database is only +** read-locked while it is actually being read, it is not locked +** continuously for the entire operation. Thus, the backup may be +** performed on a live database without preventing other users from +** writing to the database for an extended period of time. +** +** To perform a backup operation: +** <ol> +** <li><b>sqlite3_backup_init()</b> is called once to initialize the +** backup, +** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer +** the data between the two databases, and finally +** <li><b>sqlite3_backup_finish()</b> is called to release all resources +** associated with the backup operation. +** </ol> +** There should be exactly one call to sqlite3_backup_finish() for each +** successful call to sqlite3_backup_init(). +** +** <b>sqlite3_backup_init()</b> +** +** The first two arguments passed to [sqlite3_backup_init()] are the database +** handle associated with the destination database and the database name +** used to attach the destination database to the handle. The database name +** is "main" for the main database, "temp" for the temporary database, or +** the name specified as part of the [ATTACH] statement if the destination is +** an attached database. The third and fourth arguments passed to +** sqlite3_backup_init() identify the [database connection] +** and database name used +** to access the source database. The values passed for the source and +** destination [database connection] parameters must not be the same. +** +** If an error occurs within sqlite3_backup_init(), then NULL is returned +** and an error code and error message written into the [database connection] +** passed as the first argument. They may be retrieved using the +** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. +** Otherwise, if successful, a pointer to an [sqlite3_backup] object is +** returned. This pointer may be used with the sqlite3_backup_step() and +** sqlite3_backup_finish() functions to perform the specified backup +** operation. +** +** <b>sqlite3_backup_step()</b> +** +** Function [sqlite3_backup_step()] is used to copy up to nPage pages between +** the source and destination databases, where nPage is the value of the +** second parameter passed to sqlite3_backup_step(). If nPage is a negative +** value, all remaining source pages are copied. If the required pages are +** succesfully copied, but there are still more pages to copy before the +** backup is complete, it returns [SQLITE_OK]. If no error occured and there +** are no more pages to copy, then [SQLITE_DONE] is returned. If an error +** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and +** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], +** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. +** +** As well as the case where the destination database file was opened for +** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if +** the destination is an in-memory database with a different page size +** from the source database. +** +** If sqlite3_backup_step() cannot obtain a required file-system lock, then +** the [sqlite3_busy_handler | busy-handler function] +** is invoked (if one is specified). If the +** busy-handler returns non-zero before the lock is available, then +** [SQLITE_BUSY] is returned to the caller. In this case the call to +** sqlite3_backup_step() can be retried later. If the source +** [database connection] +** is being used to write to the source database when sqlite3_backup_step() +** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this +** case the call to sqlite3_backup_step() can be retried later on. If +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or +** [SQLITE_READONLY] is returned, then +** there is no point in retrying the call to sqlite3_backup_step(). These +** errors are considered fatal. At this point the application must accept +** that the backup operation has failed and pass the backup operation handle +** to the sqlite3_backup_finish() to release associated resources. +** +** Following the first call to sqlite3_backup_step(), an exclusive lock is +** obtained on the destination file. It is not released until either +** sqlite3_backup_finish() is called or the backup operation is complete +** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time +** a call to sqlite3_backup_step() is made a [shared lock] is obtained on +** the source database file. This lock is released before the +** sqlite3_backup_step() call returns. Because the source database is not +** locked between calls to sqlite3_backup_step(), it may be modified mid-way +** through the backup procedure. If the source database is modified by an +** external process or via a database connection other than the one being +** used by the backup operation, then the backup will be transparently +** restarted by the next call to sqlite3_backup_step(). If the source +** database is modified by the using the same database connection as is used +** by the backup operation, then the backup database is transparently +** updated at the same time. +** +** <b>sqlite3_backup_finish()</b> +** +** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the +** application wishes to abandon the backup operation, the [sqlite3_backup] +** object should be passed to sqlite3_backup_finish(). This releases all +** resources associated with the backup operation. If sqlite3_backup_step() +** has not yet returned [SQLITE_DONE], then any active write-transaction on the +** destination database is rolled back. The [sqlite3_backup] object is invalid +** and may not be used following a call to sqlite3_backup_finish(). +** +** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error +** occurred, regardless or whether or not sqlite3_backup_step() was called +** a sufficient number of times to complete the backup operation. Or, if +** an out-of-memory condition or IO error occured during a call to +** sqlite3_backup_step() then [SQLITE_NOMEM] or an +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code +** is returned. In this case the error code and an error message are +** written to the destination [database connection]. +** +** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is +** not a permanent error and does not affect the return value of +** sqlite3_backup_finish(). +** +** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> +** +** Each call to sqlite3_backup_step() sets two values stored internally +** by an [sqlite3_backup] object. The number of pages still to be backed +** up, which may be queried by sqlite3_backup_remaining(), and the total +** number of pages in the source database file, which may be queried by +** sqlite3_backup_pagecount(). +** +** The values returned by these functions are only updated by +** sqlite3_backup_step(). If the source database is modified during a backup +** operation, then the values are not updated to account for any extra +** pages that need to be updated or the size of the source database file +** changing. +** +** <b>Concurrent Usage of Database Handles</b> +** +** The source [database connection] may be used by the application for other +** purposes while a backup operation is underway or being initialized. +** If SQLite is compiled and configured to support threadsafe database +** connections, then the source database connection may be used concurrently +** from within other threads. +** +** However, the application must guarantee that the destination database +** connection handle is not passed to any other API (by any thread) after +** sqlite3_backup_init() is called and before the corresponding call to +** sqlite3_backup_finish(). Unfortunately SQLite does not currently check +** for this, if the application does use the destination [database connection] +** for some other purpose during a backup operation, things may appear to +** work correctly but in fact be subtly malfunctioning. Use of the +** destination database connection while a backup is in progress might +** also cause a mutex deadlock. +** +** Furthermore, if running in [shared cache mode], the application must +** guarantee that the shared cache used by the destination database +** is not accessed while the backup is running. In practice this means +** that the application must guarantee that the file-system file being +** backed up to is not accessed by any connection within the process, +** not just the specific connection that was passed to sqlite3_backup_init(). +** +** The [sqlite3_backup] object itself is partially threadsafe. Multiple +** threads may safely make multiple concurrent calls to sqlite3_backup_step(). +** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() +** APIs are not strictly speaking threadsafe. If they are invoked at the +** same time as another thread is invoking sqlite3_backup_step() it is +** possible that they return invalid values. +*/ +SQLITE_API sqlite3_backup *sqlite3_backup_init( + sqlite3 *pDest, /* Destination database handle */ + const char *zDestName, /* Destination database name */ + sqlite3 *pSource, /* Source database handle */ + const char *zSourceName /* Source database name */ +); +SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); +SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); +SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); +SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); + +/* +** CAPI3REF: Unlock Notification +** EXPERIMENTAL +** +** When running in shared-cache mode, a database operation may fail with +** an [SQLITE_LOCKED] error if the required locks on the shared-cache or +** individual tables within the shared-cache cannot be obtained. See +** [SQLite Shared-Cache Mode] for a description of shared-cache locking. +** This API may be used to register a callback that SQLite will invoke +** when the connection currently holding the required lock relinquishes it. +** This API is only available if the library was compiled with the +** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. +** +** See Also: [Using the SQLite Unlock Notification Feature]. +** +** Shared-cache locks are released when a database connection concludes +** its current transaction, either by committing it or rolling it back. +** +** When a connection (known as the blocked connection) fails to obtain a +** shared-cache lock and SQLITE_LOCKED is returned to the caller, the +** identity of the database connection (the blocking connection) that +** has locked the required resource is stored internally. After an +** application receives an SQLITE_LOCKED error, it may call the +** sqlite3_unlock_notify() method with the blocked connection handle as +** the first argument to register for a callback that will be invoked +** when the blocking connections current transaction is concluded. The +** callback is invoked from within the [sqlite3_step] or [sqlite3_close] +** call that concludes the blocking connections transaction. +** +** If sqlite3_unlock_notify() is called in a multi-threaded application, +** there is a chance that the blocking connection will have already +** concluded its transaction by the time sqlite3_unlock_notify() is invoked. +** If this happens, then the specified callback is invoked immediately, +** from within the call to sqlite3_unlock_notify(). +** +** If the blocked connection is attempting to obtain a write-lock on a +** shared-cache table, and more than one other connection currently holds +** a read-lock on the same table, then SQLite arbitrarily selects one of +** the other connections to use as the blocking connection. +** +** There may be at most one unlock-notify callback registered by a +** blocked connection. If sqlite3_unlock_notify() is called when the +** blocked connection already has a registered unlock-notify callback, +** then the new callback replaces the old. If sqlite3_unlock_notify() is +** called with a NULL pointer as its second argument, then any existing +** unlock-notify callback is cancelled. The blocked connections +** unlock-notify callback may also be canceled by closing the blocked +** connection using [sqlite3_close()]. +** +** The unlock-notify callback is not reentrant. If an application invokes +** any sqlite3_xxx API functions from within an unlock-notify callback, a +** crash or deadlock may be the result. +** +** Unless deadlock is detected (see below), sqlite3_unlock_notify() always +** returns SQLITE_OK. +** +** <b>Callback Invocation Details</b> +** +** When an unlock-notify callback is registered, the application provides a +** single void* pointer that is passed to the callback when it is invoked. +** However, the signature of the callback function allows SQLite to pass +** it an array of void* context pointers. The first argument passed to +** an unlock-notify callback is a pointer to an array of void* pointers, +** and the second is the number of entries in the array. +** +** When a blocking connections transaction is concluded, there may be +** more than one blocked connection that has registered for an unlock-notify +** callback. If two or more such blocked connections have specified the +** same callback function, then instead of invoking the callback function +** multiple times, it is invoked once with the set of void* context pointers +** specified by the blocked connections bundled together into an array. +** This gives the application an opportunity to prioritize any actions +** related to the set of unblocked database connections. +** +** <b>Deadlock Detection</b> +** +** Assuming that after registering for an unlock-notify callback a +** database waits for the callback to be issued before taking any further +** action (a reasonable assumption), then using this API may cause the +** application to deadlock. For example, if connection X is waiting for +** connection Y's transaction to be concluded, and similarly connection +** Y is waiting on connection X's transaction, then neither connection +** will proceed and the system may remain deadlocked indefinitely. +** +** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock +** detection. If a given call to sqlite3_unlock_notify() would put the +** system in a deadlocked state, then SQLITE_LOCKED is returned and no +** unlock-notify callback is registered. The system is said to be in +** a deadlocked state if connection A has registered for an unlock-notify +** callback on the conclusion of connection B's transaction, and connection +** B has itself registered for an unlock-notify callback when connection +** A's transaction is concluded. Indirect deadlock is also detected, so +** the system is also considered to be deadlocked if connection B has +** registered for an unlock-notify callback on the conclusion of connection +** C's transaction, where connection C is waiting on connection A. Any +** number of levels of indirection are allowed. +** +** <b>The "DROP TABLE" Exception</b> +** +** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost +** always appropriate to call sqlite3_unlock_notify(). There is however, +** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, +** SQLite checks if there are any currently executing SELECT statements +** that belong to the same connection. If there are, SQLITE_LOCKED is +** returned. In this case there is no "blocking connection", so invoking +** sqlite3_unlock_notify() results in the unlock-notify callback being +** invoked immediately. If the application then re-attempts the "DROP TABLE" +** or "DROP INDEX" query, an infinite loop might be the result. +** +** One way around this problem is to check the extended error code returned +** by an sqlite3_step() call. If there is a blocking connection, then the +** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in +** the special "DROP TABLE/INDEX" case, the extended error code is just +** SQLITE_LOCKED. +*/ +SQLITE_API int sqlite3_unlock_notify( + sqlite3 *pBlocked, /* Waiting connection */ + void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ + void *pNotifyArg /* Argument to pass to xNotify */ +); + + +/* +** CAPI3REF: String Comparison +** EXPERIMENTAL +** +** The [sqlite3_strnicmp()] API allows applications and extensions to +** compare the contents of two buffers containing UTF-8 strings in a +** case-indendent fashion, using the same definition of case independence +** that SQLite uses internally when comparing identifiers. +*/ +SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); + +/* +** Undo the hack that converts floating point types to integer for +** builds on processors without floating point support. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# undef double +#endif + +#ifdef __cplusplus +} /* End of the 'extern "C"' block */ +#endif +#endif + |