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 ** $Id: vdbe.h,v 1.85 2004/06/05 10:22:18 danielk1977 Exp $ 19 */ 20 #ifndef _SQLITE_VDBE_H_ 21 #define _SQLITE_VDBE_H_ 22 #include <stdio.h> 23 24 /* 25 ** A single VDBE is an opaque structure named "Vdbe". Only routines 26 ** in the source file sqliteVdbe.c are allowed to see the insides 27 ** of this structure. 28 */ 29 typedef struct Vdbe Vdbe; 30 31 /* 32 ** A single instruction of the virtual machine has an opcode 33 ** and as many as three operands. The instruction is recorded 34 ** as an instance of the following structure: 35 */ 36 struct VdbeOp { 37 u8 opcode; /* What operation to perform */ 38 int p1; /* First operand */ 39 int p2; /* Second parameter (often the jump destination) */ 40 char *p3; /* Third parameter */ 41 int p3type; /* P3_STATIC, P3_DYNAMIC or P3_POINTER */ 42 #ifndef NDEBUG 43 char *zComment; /* Comments explaining what this opcode does */ 44 #endif 45 #ifdef VDBE_PROFILE 46 int cnt; /* Number of times this instruction was executed */ 47 long long cycles; /* Total time spend executing this instruction */ 48 #endif 49 }; 50 typedef struct VdbeOp VdbeOp; 51 52 /* 53 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because 54 ** it takes up less space. 55 */ 56 struct VdbeOpList { 57 u8 opcode; /* What operation to perform */ 58 signed char p1; /* First operand */ 59 short int p2; /* Second parameter (often the jump destination) */ 60 char *p3; /* Third parameter */ 61 }; 62 typedef struct VdbeOpList VdbeOpList; 63 64 /* 65 ** Allowed values of VdbeOp.p3type 66 */ 67 #define P3_NOTUSED 0 /* The P3 parameter is not used */ 68 #define P3_DYNAMIC (-1) /* Pointer to a string obtained from sqliteMalloc() */ 69 #define P3_STATIC (-2) /* Pointer to a static string */ 70 #define P3_POINTER (-3) /* P3 is a pointer to some structure or object */ 71 #define P3_COLLSEQ (-4) /* P3 is a pointer to a CollSeq structure */ 72 #define P3_FUNCDEF (-5) /* P3 is a pointer to a FuncDef structure */ 73 #define P3_KEYINFO (-6) /* P3 is a pointer to a KeyInfo structure */ 74 #define P3_VDBEFUNC (-7) /* P3 is a pointer to a VdbeFunc structure */ 75 76 /* When adding a P3 argument using P3_KEYINFO, a copy of the KeyInfo structure 77 ** is made. That copy is freed when the Vdbe is finalized. But if the 78 ** argument is P3_KEYINFO_HANDOFF, the passed in pointer is used. It still 79 ** gets freed when the Vdbe is finalized so it still should be obtained 80 ** from a single sqliteMalloc(). But no copy is made and the calling 81 ** function should *not* try to free the KeyInfo. 82 */ 83 #define P3_KEYINFO_HANDOFF (-7) 84 85 /* 86 ** The following macro converts a relative address in the p2 field 87 ** of a VdbeOp structure into a negative number so that 88 ** sqlite3VdbeAddOpList() knows that the address is relative. Calling 89 ** the macro again restores the address. 90 */ 91 #define ADDR(X) (-1-(X)) 92 93 /* 94 ** The makefile scans the vdbe.c source file and creates the "opcodes.h" 95 ** header file that defines a number for each opcode used by the VDBE. 96 */ 97 #include "opcodes.h" 98 99 /* 100 ** Prototypes for the VDBE interface. See comments on the implementation 101 ** for a description of what each of these routines does. 102 */ 103 Vdbe *sqlite3VdbeCreate(sqlite*); 104 void sqlite3VdbeCreateCallback(Vdbe*, int*); 105 int sqlite3VdbeAddOp(Vdbe*,int,int,int); 106 int sqlite3VdbeOp3(Vdbe*,int,int,int,const char *zP3,int); 107 int sqlite3VdbeCode(Vdbe*,...); 108 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp); 109 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1); 110 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2); 111 void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N); 112 void sqlite3VdbeDequoteP3(Vdbe*, int addr); 113 int sqlite3VdbeFindOp(Vdbe*, int, int, int); 114 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int); 115 int sqlite3VdbeMakeLabel(Vdbe*); 116 void sqlite3VdbeDelete(Vdbe*); 117 void sqlite3VdbeMakeReady(Vdbe*,int,int); 118 int sqlite3VdbeFinalize(Vdbe*,char**); 119 void sqlite3VdbeResolveLabel(Vdbe*, int); 120 int sqlite3VdbeCurrentAddr(Vdbe*); 121 void sqlite3VdbeTrace(Vdbe*,FILE*); 122 void sqlite3VdbeCompressSpace(Vdbe*,int); 123 int sqlite3VdbeReset(Vdbe*,char **); 124 int sqliteVdbeSetVariables(Vdbe*,int,const char**); 125 void sqlite3VdbeSetNumCols(Vdbe*,int); 126 int sqlite3VdbeSetColName(Vdbe*, int, const char *, int); 127 128 #ifndef NDEBUG 129 void sqlite3VdbeComment(Vdbe*, const char*, ...); 130 # define VdbeComment(X) sqlite3VdbeComment X 131 #else 132 # define VdbeComment(X) 133 #endif 134 135 #endif 136