src/vdbe.h

   1 /*
   2 ** 2001 September 15
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 *************************************************************************
  12 ** Header file for the Virtual DataBase Engine (VDBE)
  13 **
  14 ** This header defines the interface to the virtual database engine
  15 ** or VDBE.  The VDBE implements an abstract machine that runs a
  16 ** simple program to access and modify the underlying database.
  17 */
  18 #ifndef _SQLITE_VDBE_H_
  19 #define _SQLITE_VDBE_H_
  20 #include <stdio.h>
  21
  22 /*
  23 ** A single VDBE is an opaque structure named "Vdbe".  Only routines
  24 ** in the source file sqliteVdbe.c are allowed to see the insides
  25 ** of this structure.
  26 */
  27 typedef struct Vdbe Vdbe;
  28
  29 /*
  30 ** The names of the following types declared in vdbeInt.h are required
  31 ** for the VdbeOp definition.
  32 */
  33 typedef struct VdbeFunc VdbeFunc;
  34 typedef struct Mem Mem;
  35 typedef struct SubProgram SubProgram;
  36
  37 /*
  38 ** A single instruction of the virtual machine has an opcode
  39 ** and as many as three operands.  The instruction is recorded
  40 ** as an instance of the following structure:
  41 */
  42 struct VdbeOp {
  43   u8 opcode;          /* What operation to perform */
  44   signed char p4type; /* One of the P4_xxx constants for p4 */
  45   u8 opflags;         /* Mask of the OPFLG_* flags in opcodes.h */
  46   u8 p5;              /* Fifth parameter is an unsigned character */
  47   int p1;             /* First operand */
  48   int p2;             /* Second parameter (often the jump destination) */
  49   int p3;             /* The third parameter */
  50   union {             /* fourth parameter */
  51     int i;                 /* Integer value if p4type==P4_INT32 */
  52     void *p;               /* Generic pointer */
  53     char *z;               /* Pointer to data for string (char array) types */
  54     i64 *pI64;             /* Used when p4type is P4_INT64 */
  55     double *pReal;         /* Used when p4type is P4_REAL */
  56     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
  57     VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
  58     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
  59     Mem *pMem;             /* Used when p4type is P4_MEM */
  60     VTable *pVtab;         /* Used when p4type is P4_VTAB */
  61     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
  62     int *ai;               /* Used when p4type is P4_INTARRAY */
  63     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
  64     int (*xAdvance)(BtCursor *, int *);
  65   } p4;
  66 #ifdef SQLITE_DEBUG
  67   char *zComment;          /* Comment to improve readability */
  68 #endif
  69 #ifdef VDBE_PROFILE
  70   int cnt;                 /* Number of times this instruction was executed */
  71   u64 cycles;              /* Total time spent executing this instruction */
  72 #endif
  73 };
  74 typedef struct VdbeOp VdbeOp;
  75
  76
  77 /*
  78 ** A sub-routine used to implement a trigger program.
  79 */
  80 struct SubProgram {
  81   VdbeOp *aOp;                  /* Array of opcodes for sub-program */
  82   int nOp;                      /* Elements in aOp[] */
  83   int nMem;                     /* Number of memory cells required */
  84   int nCsr;                     /* Number of cursors required */
  85   int nOnce;                    /* Number of OP_Once instructions */
  86   void *token;                  /* id that may be used to recursive triggers */
  87   SubProgram *pNext;            /* Next sub-program already visited */
  88 };
  89
  90 /*
  91 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
  92 ** it takes up less space.
  93 */
  94 struct VdbeOpList {
  95   u8 opcode;          /* What operation to perform */
  96   signed char p1;     /* First operand */
  97   signed char p2;     /* Second parameter (often the jump destination) */
  98   signed char p3;     /* Third parameter */
  99 };
 100 typedef struct VdbeOpList VdbeOpList;
 101
 102 /*
 103 ** Allowed values of VdbeOp.p4type
 104 */
 105 #define P4_NOTUSED    0   /* The P4 parameter is not used */
 106 #define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
 107 #define P4_STATIC   (-2)  /* Pointer to a static string */
 108 #define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
 109 #define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
 110 #define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
 111 #define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
 112 #define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
 113 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
 114 #define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
 115 #define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
 116 #define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
 117 #define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
 118 #define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
 119 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
 120 #define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
 121 #define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
 122
 123 /* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
 124 ** is made.  That copy is freed when the Vdbe is finalized.  But if the
 125 ** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
 126 ** gets freed when the Vdbe is finalized so it still should be obtained
 127 ** from a single sqliteMalloc().  But no copy is made and the calling
 128 ** function should *not* try to free the KeyInfo.
 129 */
 130 #define P4_KEYINFO_HANDOFF (-16)
 131 #define P4_KEYINFO_STATIC  (-17)
 132
 133 /*
 134 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
 135 ** number of columns of data returned by the statement.
 136 */
 137 #define COLNAME_NAME     0
 138 #define COLNAME_DECLTYPE 1
 139 #define COLNAME_DATABASE 2
 140 #define COLNAME_TABLE    3
 141 #define COLNAME_COLUMN   4
 142 #ifdef SQLITE_ENABLE_COLUMN_METADATA
 143 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
 144 #else
 145 # ifdef SQLITE_OMIT_DECLTYPE
 146 #   define COLNAME_N      1      /* Store only the name */
 147 # else
 148 #   define COLNAME_N      2      /* Store the name and decltype */
 149 # endif
 150 #endif
 151
 152 /*
 153 ** The following macro converts a relative address in the p2 field
 154 ** of a VdbeOp structure into a negative number so that
 155 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
 156 ** the macro again restores the address.
 157 */
 158 #define ADDR(X)  (-1-(X))
 159
 160 /*
 161 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
 162 ** header file that defines a number for each opcode used by the VDBE.
 163 */
 164 #include "opcodes.h"
 165
 166 /*
 167 ** Prototypes for the VDBE interface.  See comments on the implementation
 168 ** for a description of what each of these routines does.
 169 */
 170 Vdbe *sqlite3VdbeCreate(sqlite3*);
 171 int sqlite3VdbeAddOp0(Vdbe*,int);
 172 int sqlite3VdbeAddOp1(Vdbe*,int,int);
 173 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
 174 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 175 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
 176 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 177 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
 178 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
 179 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 180 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 181 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 182 void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
 183 void sqlite3VdbeJumpHere(Vdbe*, int addr);
 184 void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 185 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
 186 void sqlite3VdbeUsesBtree(Vdbe*, int);
 187 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 188 int sqlite3VdbeMakeLabel(Vdbe*);
 189 void sqlite3VdbeRunOnlyOnce(Vdbe*);
 190 void sqlite3VdbeDelete(Vdbe*);
 191 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
 192 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 193 int sqlite3VdbeFinalize(Vdbe*);
 194 void sqlite3VdbeResolveLabel(Vdbe*, int);
 195 int sqlite3VdbeCurrentAddr(Vdbe*);
 196 #ifdef SQLITE_DEBUG
 197   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
 198   void sqlite3VdbeTrace(Vdbe*,FILE*);
 199 #endif
 200 void sqlite3VdbeResetStepResult(Vdbe*);
 201 void sqlite3VdbeRewind(Vdbe*);
 202 int sqlite3VdbeReset(Vdbe*);
 203 void sqlite3VdbeSetNumCols(Vdbe*,int);
 204 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
 205 void sqlite3VdbeCountChanges(Vdbe*);
 206 sqlite3 *sqlite3VdbeDb(Vdbe*);
 207 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
 208 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 209 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
 210 sqlite3_value *sqlite3VdbeGetValue(Vdbe*, int, u8);
 211 void sqlite3VdbeSetVarmask(Vdbe*, int);
 212 #ifndef SQLITE_OMIT_TRACE
 213   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
 214 #endif
 215
 216 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 217 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
 218 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);
 219
 220 #ifndef SQLITE_OMIT_TRIGGER
 221 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 222 #endif
 223
 224
 225 #ifndef NDEBUG
 226   void sqlite3VdbeComment(Vdbe*, const char*, ...);
 227 # define VdbeComment(X)  sqlite3VdbeComment X
 228   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 229 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
 230 #else
 231 # define VdbeComment(X)
 232 # define VdbeNoopComment(X)
 233 #endif
 234
 235 #endif