/*** 2001 September 15**** The author disclaims copyright to this source code.  In place of** a legal notice, here is a blessing:****    May you do good and not evil.**    May you find forgiveness for yourself and forgive others.**    May you share freely, never taking more than you give.***************************************************************************** Header file for the Virtual DataBase Engine (VDBE)**** This header defines the interface to the virtual database engine** or VDBE.  The VDBE implements an abstract machine that runs a** simple program to access and modify the underlying database.**** $Id: vdbe.h,v 1.99 2005/09/20 17:42:23 drh Exp $*/#ifndef _SQLITE_VDBE_H_#define _SQLITE_VDBE_H_#include <stdio.h>/*** A single VDBE is an opaque structure named "Vdbe".  Only routines** in the source file sqliteVdbe.c are allowed to see the insides** of this structure.*/typedef struct Vdbe Vdbe;/*** A single instruction of the virtual machine has an opcode** and as many as three operands.  The instruction is recorded** as an instance of the following structure:*/struct VdbeOp {  u8 opcode;          /* What operation to perform */  int p1;             /* First operand */  int p2;             /* Second parameter (often the jump destination) */  char *p3;           /* Third parameter */  int p3type;         /* One of the P3_xxx constants defined below */#ifdef VDBE_PROFILE  int cnt;            /* Number of times this instruction was executed */  long long cycles;   /* Total time spend executing this instruction */#endif};typedef struct VdbeOp VdbeOp;/*** A smaller version of VdbeOp used for the VdbeAddOpList() function because** it takes up less space.*/struct VdbeOpList {  u8 opcode;          /* What operation to perform */  signed char p1;     /* First operand */  short int p2;       /* Second parameter (often the jump destination) */  char *p3;           /* Third parameter */};typedef struct VdbeOpList VdbeOpList;/*** Allowed values of VdbeOp.p3type*/#define P3_NOTUSED    0   /* The P3 parameter is not used */#define P3_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */#define P3_STATIC   (-2)  /* Pointer to a static string */#define P3_COLLSEQ  (-4)  /* P3 is a pointer to a CollSeq structure */#define P3_FUNCDEF  (-5)  /* P3 is a pointer to a FuncDef structure */#define P3_KEYINFO  (-6)  /* P3 is a pointer to a KeyInfo structure */#define P3_VDBEFUNC (-7)  /* P3 is a pointer to a VdbeFunc structure */#define P3_MEM      (-8)  /* P3 is a pointer to a Mem*    structure *//* When adding a P3 argument using P3_KEYINFO, a copy of the KeyInfo structure** is made.  That copy is freed when the Vdbe is finalized.  But if the** argument is P3_KEYINFO_HANDOFF, the passed in pointer is used.  It still** gets freed when the Vdbe is finalized so it still should be obtained** from a single sqliteMalloc().  But no copy is made and the calling** function should *not* try to free the KeyInfo.*/#define P3_KEYINFO_HANDOFF (-9)/*** The following macro converts a relative address in the p2 field** of a VdbeOp structure into a negative number so that ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling** the macro again restores the address.*/#define ADDR(X)  (-1-(X))/*** The makefile scans the vdbe.c source file and creates the "opcodes.h"** header file that defines a number for each opcode used by the VDBE.*/#include "opcodes.h"/*** Prototypes for the VDBE interface.  See comments on the implementation** for a description of what each of these routines does.*/Vdbe *sqlite3VdbeCreate(sqlite3*);void sqlite3VdbeCreateCallback(Vdbe*, int*);int sqlite3VdbeAddOp(Vdbe*,int,int,int);int sqlite3VdbeOp3(Vdbe*,int,int,int,const char *zP3,int);int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);void sqlite3VdbeJumpHere(Vdbe*, int addr);void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N);VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);int sqlite3VdbeMakeLabel(Vdbe*);void sqlite3VdbeDelete(Vdbe*);void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);int sqlite3VdbeFinalize(Vdbe*);void sqlite3VdbeResolveLabel(Vdbe*, int);int sqlite3VdbeCurrentAddr(Vdbe*);void sqlite3VdbeTrace(Vdbe*,FILE*);int sqlite3VdbeReset(Vdbe*);int sqliteVdbeSetVariables(Vdbe*,int,const char**);void sqlite3VdbeSetNumCols(Vdbe*,int);int sqlite3VdbeSetColName(Vdbe*, int, const char *, int);void sqlite3VdbeCountChanges(Vdbe*);sqlite3 *sqlite3VdbeDb(Vdbe*);#ifndef NDEBUG  void sqlite3VdbeComment(Vdbe*, const char*, ...);# define VdbeComment(X)  sqlite3VdbeComment X#else# define VdbeComment(X)#endif#endif