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 } p4; 65 #ifdef SQLITE_DEBUG 66 char *zComment; /* Comment to improve readability */ 67 #endif 68 #ifdef VDBE_PROFILE 69 int cnt; /* Number of times this instruction was executed */ 70 u64 cycles; /* Total time spent executing this instruction */ 71 #endif 72 }; 73 typedef struct VdbeOp VdbeOp; 74 75 76 /* 77 ** A sub-routine used to implement a trigger program. 78 */ 79 struct SubProgram { 80 VdbeOp *aOp; /* Array of opcodes for sub-program */ 81 int nOp; /* Elements in aOp[] */ 82 int nMem; /* Number of memory cells required */ 83 int nCsr; /* Number of cursors required */ 84 void *token; /* id that may be used to recursive triggers */ 85 SubProgram *pNext; /* Next sub-program already visited */ 86 }; 87 88 /* 89 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because 90 ** it takes up less space. 91 */ 92 struct VdbeOpList { 93 u8 opcode; /* What operation to perform */ 94 signed char p1; /* First operand */ 95 signed char p2; /* Second parameter (often the jump destination) */ 96 signed char p3; /* Third parameter */ 97 }; 98 typedef struct VdbeOpList VdbeOpList; 99 100 /* 101 ** Allowed values of VdbeOp.p4type 102 */ 103 #define P4_NOTUSED 0 /* The P4 parameter is not used */ 104 #define P4_DYNAMIC (-1) /* Pointer to a string obtained from sqliteMalloc() */ 105 #define P4_STATIC (-2) /* Pointer to a static string */ 106 #define P4_COLLSEQ (-4) /* P4 is a pointer to a CollSeq structure */ 107 #define P4_FUNCDEF (-5) /* P4 is a pointer to a FuncDef structure */ 108 #define P4_KEYINFO (-6) /* P4 is a pointer to a KeyInfo structure */ 109 #define P4_VDBEFUNC (-7) /* P4 is a pointer to a VdbeFunc structure */ 110 #define P4_MEM (-8) /* P4 is a pointer to a Mem* structure */ 111 #define P4_TRANSIENT 0 /* P4 is a pointer to a transient string */ 112 #define P4_VTAB (-10) /* P4 is a pointer to an sqlite3_vtab structure */ 113 #define P4_MPRINTF (-11) /* P4 is a string obtained from sqlite3_mprintf() */ 114 #define P4_REAL (-12) /* P4 is a 64-bit floating point value */ 115 #define P4_INT64 (-13) /* P4 is a 64-bit signed integer */ 116 #define P4_INT32 (-14) /* P4 is a 32-bit signed integer */ 117 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */ 118 #define P4_SUBPROGRAM (-18) /* P4 is a pointer to a SubProgram structure */ 119 120 /* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure 121 ** is made. That copy is freed when the Vdbe is finalized. But if the 122 ** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used. It still 123 ** gets freed when the Vdbe is finalized so it still should be obtained 124 ** from a single sqliteMalloc(). But no copy is made and the calling 125 ** function should *not* try to free the KeyInfo. 126 */ 127 #define P4_KEYINFO_HANDOFF (-16) 128 #define P4_KEYINFO_STATIC (-17) 129 130 /* 131 ** The Vdbe.aColName array contains 5n Mem structures, where n is the 132 ** number of columns of data returned by the statement. 133 */ 134 #define COLNAME_NAME 0 135 #define COLNAME_DECLTYPE 1 136 #define COLNAME_DATABASE 2 137 #define COLNAME_TABLE 3 138 #define COLNAME_COLUMN 4 139 #ifdef SQLITE_ENABLE_COLUMN_METADATA 140 # define COLNAME_N 5 /* Number of COLNAME_xxx symbols */ 141 #else 142 # ifdef SQLITE_OMIT_DECLTYPE 143 # define COLNAME_N 1 /* Store only the name */ 144 # else 145 # define COLNAME_N 2 /* Store the name and decltype */ 146 # endif 147 #endif 148 149 /* 150 ** The following macro converts a relative address in the p2 field 151 ** of a VdbeOp structure into a negative number so that 152 ** sqlite3VdbeAddOpList() knows that the address is relative. Calling 153 ** the macro again restores the address. 154 */ 155 #define ADDR(X) (-1-(X)) 156 157 /* 158 ** The makefile scans the vdbe.c source file and creates the "opcodes.h" 159 ** header file that defines a number for each opcode used by the VDBE. 160 */ 161 #include "opcodes.h" 162 163 /* 164 ** Prototypes for the VDBE interface. See comments on the implementation 165 ** for a description of what each of these routines does. 166 */ 167 Vdbe *sqlite3VdbeCreate(sqlite3*); 168 int sqlite3VdbeAddOp0(Vdbe*,int); 169 int sqlite3VdbeAddOp1(Vdbe*,int,int); 170 int sqlite3VdbeAddOp2(Vdbe*,int,int,int); 171 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int); 172 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int); 173 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int); 174 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp); 175 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1); 176 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2); 177 void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3); 178 void sqlite3VdbeChangeP5(Vdbe*, u8 P5); 179 void sqlite3VdbeJumpHere(Vdbe*, int addr); 180 void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N); 181 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N); 182 void sqlite3VdbeUsesBtree(Vdbe*, int); 183 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int); 184 int sqlite3VdbeMakeLabel(Vdbe*); 185 void sqlite3VdbeRunOnlyOnce(Vdbe*); 186 void sqlite3VdbeDelete(Vdbe*); 187 void sqlite3VdbeDeleteObject(sqlite3*,Vdbe*); 188 void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int,int,int); 189 int sqlite3VdbeFinalize(Vdbe*); 190 void sqlite3VdbeResolveLabel(Vdbe*, int); 191 int sqlite3VdbeCurrentAddr(Vdbe*); 192 #ifdef SQLITE_DEBUG 193 int sqlite3VdbeAssertMayAbort(Vdbe *, int); 194 void sqlite3VdbeTrace(Vdbe*,FILE*); 195 #endif 196 void sqlite3VdbeResetStepResult(Vdbe*); 197 int sqlite3VdbeReset(Vdbe*); 198 void sqlite3VdbeSetNumCols(Vdbe*,int); 199 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*)); 200 void sqlite3VdbeCountChanges(Vdbe*); 201 sqlite3 *sqlite3VdbeDb(Vdbe*); 202 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int); 203 void sqlite3VdbeSwap(Vdbe*,Vdbe*); 204 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*); 205 sqlite3_value *sqlite3VdbeGetValue(Vdbe*, int, u8); 206 void sqlite3VdbeSetVarmask(Vdbe*, int); 207 #ifndef SQLITE_OMIT_TRACE 208 char *sqlite3VdbeExpandSql(Vdbe*, const char*); 209 #endif 210 211 UnpackedRecord *sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,char*,int); 212 void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord*); 213 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*); 214 215 #ifndef SQLITE_OMIT_TRIGGER 216 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *); 217 #endif 218 219 220 #ifndef NDEBUG 221 void sqlite3VdbeComment(Vdbe*, const char*, ...); 222 # define VdbeComment(X) sqlite3VdbeComment X 223 void sqlite3VdbeNoopComment(Vdbe*, const char*, ...); 224 # define VdbeNoopComment(X) sqlite3VdbeNoopComment X 225 #else 226 # define VdbeComment(X) 227 # define VdbeNoopComment(X) 228 #endif 229 230 #endif 231