sqliteint.h

sqlite 嵌入式数据库的源码

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.387 2005/06/12 21:35:52 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

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

#include "sqlite3.h"
#include "hash.h"
#include "parse.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stddef.h>

/*
** The maximum number of in-memory pages to use for the main database
** table and for temporary tables. Internally, the MAX_PAGES and 
** TEMP_PAGES macros are used. To override the default values at
** compilation time, the SQLITE_DEFAULT_CACHE_SIZE and 
** SQLITE_DEFAULT_TEMP_CACHE_SIZE macros should be set.
*/
#ifdef SQLITE_DEFAULT_CACHE_SIZE
# define MAX_PAGES SQLITE_DEFAULT_CACHE_SIZE
#else
# define MAX_PAGES   2000
#endif
#ifdef SQLITE_DEFAULT_TEMP_CACHE_SIZE
# define TEMP_PAGES SQLITE_DEFAULT_TEMP_CACHE_SIZE
#else
# define TEMP_PAGES   500
#endif

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

/*
** If the following macro is set to 1, then NULL values are considered
** distinct for the SELECT DISTINCT statement and for UNION or EXCEPT
** compound queries.  No other SQL database engine (among those tested) 
** works this way except for OCELOT.  But the SQL92 spec implies that
** this is how things should work.
**
** If the following macro is set to 0, then NULLs are indistinct for
** SELECT DISTINCT and for UNION.
*/
#define NULL_ALWAYS_DISTINCT 0

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

/*
** The maximum number of attached databases.  This must be at least 2
** in order to support the main database file (0) and the file used to
** hold temporary tables (1).  And it must be less than 32 because
** we use a bitmask of databases with a u32 in places (for example
** the Parse.cookieMask field).
*/
#define MAX_ATTACHED 10

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

/*
** When building SQLite for embedded systems where memory is scarce,
** you can define one or more of the following macros to omit extra
** features of the library and thus keep the size of the library to
** a minimum.
*/
/* #define SQLITE_OMIT_AUTHORIZATION  1 */
/* #define SQLITE_OMIT_MEMORYDB     1 */
/* #define SQLITE_OMIT_VACUUM         1 */
/* #define SQLITE_OMIT_DATETIME_FUNCS 1 */
/* #define SQLITE_OMIT_PROGRESS_CALLBACK 1 */
/* #define SQLITE_OMIT_AUTOVACUUM */
/* #define SQLITE_OMIT_ALTERTABLE */

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

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

/*
** Integers of known sizes.  These typedefs might change for architectures
** where the sizes very.  Preprocessor macros are available so that the
** types can be conveniently redefined at compile-type.  Like this:
**
**         cc '-DUINTPTR_TYPE=long long int' ...
*/
#ifndef UINT64_TYPE
# if defined(_MSC_VER) || defined(__BORLANDC__)
#   define UINT64_TYPE unsigned __int64
# else
#   define UINT64_TYPE unsigned long long int
# endif
#endif
#ifndef UINT32_TYPE
# define UINT32_TYPE unsigned int
#endif
#ifndef UINT16_TYPE
# define UINT16_TYPE unsigned short int
#endif
#ifndef INT16_TYPE
# define INT16_TYPE short int
#endif
#ifndef UINT8_TYPE
# define UINT8_TYPE unsigned char
#endif
#ifndef INT8_TYPE
# define INT8_TYPE signed char
#endif
#ifndef LONGDOUBLE_TYPE
# define LONGDOUBLE_TYPE long double
#endif
typedef sqlite_int64 i64;          /* 8-byte signed integer */
typedef UINT64_TYPE u64;           /* 8-byte unsigned integer */
typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
typedef INT16_TYPE i16;            /* 2-byte signed integer */
typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
typedef UINT8_TYPE i8;             /* 1-byte signed integer */

/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
extern const int sqlite3one;
#define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
#define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)

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

/*
** Defer sourcing vdbe.h and btree.h until after the "u8" and 
** "BusyHandler typedefs.
*/
#include "vdbe.h"
#include "btree.h"

/*
** This macro casts a pointer to an integer.  Useful for doing
** pointer arithmetic.
*/
#define Addr(X)  ((uptr)X)

/*
** If memory allocation problems are found, recompile with
**
**      -DSQLITE_DEBUG=1
**
** to enable some sanity checking on malloc() and free().  To
** check for memory leaks, recompile with
**
**      -DSQLITE_DEBUG=2
**
** and a line of text will be written to standard error for
** each malloc() and free().  This output can be analyzed
** by an AWK script to determine if there are any leaks.
*/
#ifdef SQLITE_MEMDEBUG
# define sqliteMalloc(X)    sqlite3Malloc_(X,1,__FILE__,__LINE__)
# define sqliteMallocRaw(X) sqlite3Malloc_(X,0,__FILE__,__LINE__)
# define sqliteFree(X)      sqlite3Free_(X,__FILE__,__LINE__)
# define sqliteRealloc(X,Y) sqlite3Realloc_(X,Y,__FILE__,__LINE__)
# define sqliteStrDup(X)    sqlite3StrDup_(X,__FILE__,__LINE__)
# define sqliteStrNDup(X,Y) sqlite3StrNDup_(X,Y,__FILE__,__LINE__)
#else
# define sqliteFree          sqlite3FreeX
# define sqliteMalloc        sqlite3Malloc
# define sqliteMallocRaw     sqlite3MallocRaw
# define sqliteRealloc       sqlite3Realloc
# define sqliteStrDup        sqlite3StrDup
# define sqliteStrNDup       sqlite3StrNDup
#endif

/*
** This variable gets set if malloc() ever fails.  After it gets set,
** the SQLite library shuts down permanently.
*/
extern int sqlite3_malloc_failed;

/*
** The following global variables are used for testing and debugging
** only.  They only work if SQLITE_DEBUG is defined.
*/
#ifdef SQLITE_MEMDEBUG
extern int sqlite3_nMalloc;      /* Number of sqliteMalloc() calls */
extern int sqlite3_nFree;        /* Number of sqliteFree() calls */
extern int sqlite3_iMallocFail;  /* Fail sqliteMalloc() after this many calls */
extern int sqlite3_iMallocReset; /* Set iMallocFail to this when it reaches 0 */
#endif

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

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

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

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