sqliteint.h

最新的sqlite3.6.2源代码

** exits.  Upon entering a before or instead of trigger, lastRowid is no
** longer (since after version 2.8.12) reset to -1.
**
** The sqlite.nChange does not count changes within triggers and keeps no
** context.  It is reset at start of sqlite3_exec.
** The sqlite.lsChange represents the number of changes made by the last
** insert, update, or delete statement.  It remains constant throughout the
** length of a statement and is then updated by OP_SetCounts.  It keeps a
** context stack just like lastRowid so that the count of changes
** within a trigger is not seen outside the trigger.  Changes to views do not
** affect the value of lsChange.
** The sqlite.csChange keeps track of the number of current changes (since
** the last statement) and is used to update sqlite_lsChange.
**
** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
** store the most recent error code and, if applicable, string. The
** internal function sqlite3Error() is used to set these variables
** consistently.
*/
struct sqlite3 {
  sqlite3_vfs *pVfs;            /* OS Interface */
  int nDb;                      /* Number of backends currently in use */
  Db *aDb;                      /* All backends */
  int flags;                    /* Miscellanous flags. See below */
  int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errMask;                  /* & result codes with this before returning */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */
  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
  u8 dfltJournalMode;           /* Default journal mode for attached dbs */
  signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
  int nextPagesize;             /* Pagesize after VACUUM if >0 */
  int nTable;                   /* Number of tables in the database */
  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 priorNewRowid;            /* Last randomly generated ROWID */
  int magic;                    /* Magic number for detect library misuse */
  int nChange;                  /* Value returned by sqlite3_changes() */
  int nTotalChange;             /* Value returned by sqlite3_total_changes() */
  sqlite3_mutex *mutex;         /* Connection mutex */
  int aLimit[SQLITE_N_LIMIT];   /* Limits */
  struct sqlite3InitInfo {      /* Information used during initialization */
    int iDb;                    /* When back is being initialized */
    int newTnum;                /* Rootpage of table being initialized */
    u8 busy;                    /* TRUE if currently initializing */
  } init;
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared libraray handles */
  struct Vdbe *pVdbe;           /* List of active virtual machines */
  int activeVdbeCnt;            /* Number of vdbes currently executing */
  void (*xTrace)(void*,const char*);        /* Trace function */
  void *pTraceArg;                          /* Argument to the trace function */
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
  void *pUpdateArg;
  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
  void *pCollNeededArg;
  sqlite3_value *pErr;          /* Most recent error message */
  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
  union {
    int isInterrupted;          /* True if sqlite3_interrupt has been called */
    double notUsed1;            /* Spacer */
  } u1;
  Lookaside lookaside;          /* Lookaside malloc configuration */
#ifndef SQLITE_OMIT_AUTHORIZATION
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
                                /* Access authorization function */
  void *pAuthArg;               /* 1st argument to the access auth function */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int (*xProgress)(void *);     /* The progress callback */
  void *pProgressArg;           /* Argument to the progress callback */
  int nProgressOps;             /* Number of opcodes for progress callback */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Hash aModule;                 /* populated by sqlite3_create_module() */
  Table *pVTab;                 /* vtab with active Connect/Create method */
  sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
  int nVTrans;                  /* Allocated size of aVTrans */
#endif
  FuncDefHash aFunc;            /* Hash table of connection functions */
  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
#ifdef SQLITE_SSE
  sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
#endif
};

/*
** A macro to discover the encoding of a database.
*/
#define ENC(db) ((db)->aDb[0].pSchema->enc)

/*
** Possible values for the sqlite.flags and or Db.flags fields.
**
** On sqlite.flags, the SQLITE_InTrans value means that we have
** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
** transaction is active on that particular database file.
*/
#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
#define SQLITE_InTrans        0x00000008  /* True if in a transaction */
#define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                          /*   DELETE, or UPDATE and return */
                                          /*   the count using a callback. */
#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                          /*   result set is empty */
#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
#define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when 
                                          ** accessing read-only databases */
#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
#define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
#define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
#define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */

#define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
#define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
#define SQLITE_Vtab           0x00100000  /* There exists a virtual table */

/*
** Possible values for the sqlite.magic field.
** The numbers are obtained at random and have no special meaning, other
** than being distinct from one another.
*/
#define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
#define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
#define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
#define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
#define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */

/*
** Each SQL function is defined by an instance of the following
** structure.  A pointer to this structure is stored in the sqlite.aFunc
** hash table.  When multiple functions have the same name, the hash table
** points to a linked list of these structures.
*/
struct FuncDef {
  i8 nArg;             /* Number of arguments.  -1 means unlimited */
  u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
  u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
  u8 flags;            /* Some combination of SQLITE_FUNC_* */
  void *pUserData;     /* User data parameter */
  FuncDef *pNext;      /* Next function with same name */
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
  void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
  char *zName;         /* SQL name of the function. */
  FuncDef *pHash;      /* Next with a different name but the same hash */
};

/*
** Possible values for FuncDef.flags
*/
#define SQLITE_FUNC_LIKE     0x01  /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE     0x02  /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM    0x04  /* Ephermeral.  Delete with VDBE */

/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
** used to create the initializers for the FuncDef structures.
**
**   FUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Used to create a scalar function definition of a function zName 
**     implemented by C function xFunc that accepts nArg arguments. The
**     value passed as iArg is cast to a (void*) and made available
**     as the user-data (sqlite3_user_data()) for the function. If 
**     argument bNC is true, then the FuncDef.needCollate flag is set.
**
**   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
**     Used to create an aggregate function definition implemented by
**     the C functions xStep and xFinal. The first four parameters
**     are interpreted in the same way as the first 4 parameters to
**     FUNCTION().
**
**   LIKEFUNC(zName, nArg, pArg, flags)
**     Used to create a scalar function definition of a function zName 
**     that accepts nArg arguments and is implemented by a call to C 
**     function likeFunc. Argument pArg is cast to a (void *) and made
**     available as the function user-data (sqlite3_user_data()). The
**     FuncDef.flags variable is set to the value passed as the flags
**     parameter.
*/
#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8, bNC, 0, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName}
#define LIKEFUNC(zName, nArg, arg, flags) \
  {nArg, SQLITE_UTF8, 0, flags, (void *)arg, 0, likeFunc, 0, 0, #zName}
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
  {nArg, SQLITE_UTF8, nc, 0, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal, #zName}


/*
** Each SQLite module (virtual table definition) is defined by an
** instance of the following structure, stored in the sqlite3.aModule
** hash table.
*/
struct Module {
  const sqlite3_module *pModule;       /* Callback pointers */
  const char *zName;                   /* Name passed to create_module() */
  void *pAux;                          /* pAux passed to create_module() */
  void (*xDestroy)(void *);            /* Module destructor function */
};

/*
** information about each column of an SQL table is held in an instance
** of this structure.
*/
struct Column {
  char *zName;     /* Name of this column */
  Expr *pDflt;     /* Default value of this column */
  char *zType;     /* Data type for this column */
  char *zColl;     /* Collating sequence.  If NULL, use the default */
  u8 notNull;      /* True if there is a NOT NULL constraint */
  u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
  char affinity;   /* One of the SQLITE_AFF_... values */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u8 isHidden;     /* True if this column is 'hidden' */
#endif
};

/*
** A "Collating Sequence" is defined by an instance of the following
** structure. Conceptually, a collating sequence consists of a name and
** a comparison routine that defines the order of that sequence.
**
** There may two seperate implementations of the collation function, one
** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
** native byte order. When a collation sequence is invoked, SQLite selects
** the version that will require the least expensive encoding
** translations, if any.
**
** The CollSeq.pUser member variable is an extra parameter that passed in
** as the first argument to the UTF-8 comparison function, xCmp.
** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
** xCmp16.
**
** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
** collating sequence is undefined.  Indices built on an undefined
** collating sequence may not be read or written.
*/
struct CollSeq {
  char *zName;          /* Name of the collating sequence, UTF-8 encoded */
  u8 enc;               /* Text encoding handled by xCmp() */
  u8 type;              /* One of the SQLITE_COLL_... values below */
  void *pUser;          /* First argument to xCmp() */
  int (*xCmp)(void*,int, const void*, int, const void*);
  void (*xDel)(void*);  /* Destructor for pUser */
};

/*
** Allowed values of CollSeq.type:
*/
#define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
#define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
#define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
#define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */

/*
** A sort order can be either ASC or DESC.
*/
#define SQLITE_SO_ASC       0  /* Sort in ascending order */
#define SQLITE_SO_DESC      1  /* Sort in ascending order */

/*
** Column affinity types.
**
** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
** the speed a little by numbering the values consecutively.  
**
** But rather than start with 0 or 1, we begin with 'a'.  That way,
** when multiple affinity types are concatenated into a string and
** used as the P4 operand, they will be more readable.
**
** Note also that the numeric types are grouped together so that testing
** for a numeric type is a single comparison.
*/
#define SQLITE_AFF_TEXT     'a'
#define SQLITE_AFF_NONE     'b'
#define SQLITE_AFF_NUMERIC  'c'
#define SQLITE_AFF_INTEGER  'd'
#define SQLITE_AFF_REAL     'e'

#define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)

/*
** The SQLITE_AFF_MASK values masks off the significant bits of an
** affinity value. 
*/