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 1.71 2004/02/22 20:05:02 drh 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 #ifdef VDBE_PROFILE 43 int cnt; /* Number of times this instruction was executed */ 44 long long cycles; /* Total time spend executing this instruction */ 45 #endif 46 }; 47 typedef struct VdbeOp VdbeOp; 48 49 /* 50 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because 51 ** it takes up less space. 52 */ 53 struct VdbeOpList { 54 u8 opcode; /* What operation to perform */ 55 signed char p1; /* First operand */ 56 short int p2; /* Second parameter (often the jump destination) */ 57 char *p3; /* Third parameter */ 58 }; 59 typedef struct VdbeOpList VdbeOpList; 60 61 /* 62 ** Allowed values of VdbeOp.p3type 63 */ 64 #define P3_NOTUSED 0 /* The P3 parameter is not used */ 65 #define P3_DYNAMIC (-1) /* Pointer to a string obtained from sqliteMalloc() */ 66 #define P3_STATIC (-2) /* Pointer to a static string */ 67 #define P3_POINTER (-3) /* P3 is a pointer to some structure or object */ 68 69 /* 70 ** The following macro converts a relative address in the p2 field 71 ** of a VdbeOp structure into a negative number so that 72 ** sqliteVdbeAddOpList() knows that the address is relative. Calling 73 ** the macro again restores the address. 74 */ 75 #define ADDR(X) (-1-(X)) 76 77 /* 78 ** The makefile scans the vdbe.c source file and creates the "opcodes.h" 79 ** header file that defines a number for each opcode used by the VDBE. 80 */ 81 #include "opcodes.h" 82 83 /* 84 ** Prototypes for the VDBE interface. See comments on the implementation 85 ** for a description of what each of these routines does. 86 */ 87 Vdbe *sqliteVdbeCreate(sqlite*); 88 void sqliteVdbeCreateCallback(Vdbe*, int*); 89 int sqliteVdbeAddOp(Vdbe*,int,int,int); 90 int sqliteVdbeOp3(Vdbe*,int,int,int,const char *zP3,int); 91 int sqliteVdbeCode(Vdbe*,...); 92 int sqliteVdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp); 93 void sqliteVdbeChangeP1(Vdbe*, int addr, int P1); 94 void sqliteVdbeChangeP2(Vdbe*, int addr, int P2); 95 void sqliteVdbeChangeP3(Vdbe*, int addr, const char *zP1, int N); 96 void sqliteVdbeDequoteP3(Vdbe*, int addr); 97 int sqliteVdbeFindOp(Vdbe*, int, int); 98 VdbeOp *sqliteVdbeGetOp(Vdbe*, int); 99 int sqliteVdbeMakeLabel(Vdbe*); 100 void sqliteVdbeDelete(Vdbe*); 101 void sqliteVdbeMakeReady(Vdbe*,int,int); 102 int sqliteVdbeExec(Vdbe*); 103 int sqliteVdbeList(Vdbe*); 104 int sqliteVdbeFinalize(Vdbe*,char**); 105 void sqliteVdbeResolveLabel(Vdbe*, int); 106 int sqliteVdbeCurrentAddr(Vdbe*); 107 void sqliteVdbeTrace(Vdbe*,FILE*); 108 void sqliteVdbeCompressSpace(Vdbe*,int); 109 int sqliteVdbeReset(Vdbe*,char **); 110 int sqliteVdbeSetVariables(Vdbe*,int,const char**); 111 112 #endif 113