/*

** 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 1.138 2008/08/20 22:06:48 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;

/*

** The names of the following types declared in vdbeInt.h are required

** for the VdbeOp definition.

*/

typedef struct VdbeFunc VdbeFunc;

typedef struct Mem Mem;

/*

** 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 */

  signed char p4type; /* One of the P4_xxx constants for p4 */

  u8 opflags;         /* Not currently used */

  u8 p5;              /* Fifth parameter is an unsigned character */

  int p1;             /* First operand */

  int p2;             /* Second parameter (often the jump destination) */

  int p3;             /* The third parameter */

  union {             /* forth parameter */

    int i;                 /* Integer value if p4type==P4_INT32 */

    void *p;               /* Generic pointer */

    char *z;               /* Pointer to data for string (char array) types */

    i64 *pI64;             /* Used when p4type is P4_INT64 */

    double *pReal;         /* Used when p4type is P4_REAL */

    FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */

    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */

    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */

    Mem *pMem;             /* Used when p4type is P4_MEM */

    sqlite3_vtab *pVtab;   /* Used when p4type is P4_VTAB */

    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */

    int *ai;               /* Used when p4type is P4_INTARRAY */

  } p4;

#ifdef SQLITE_DEBUG

  char *zComment;          /* Comment to improve readability */

#endif

#ifdef VDBE_PROFILE

  int cnt;                 /* Number of times this instruction was executed */

  u64 cycles;              /* Total time spent 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 */

  signed char p2;     /* Second parameter (often the jump destination) */

  signed char p3;     /* Third parameter */

};

typedef struct VdbeOpList VdbeOpList;

/*

** Allowed values of VdbeOp.p3type

*/

#define P4_NOTUSED    0   /* The P4 parameter is not used */

#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */

#define P4_STATIC   (-2)  /* Pointer to a static string */

#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */

#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */

#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */

#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */

#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */

#define P4_TRANSIENT (-9) /* P4 is a pointer to a transient string */

#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */

#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */

#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */

#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */

#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */

#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */

/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure

** is made.  That copy is freed when the Vdbe is finalized.  But if the

** argument is P4_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 P4_KEYINFO_HANDOFF (-16)

#define P4_KEYINFO_STATIC  (-17)

/*

** The Vdbe.aColName array contains 5n Mem structures, where n is the 

** number of columns of data returned by the statement.

*/

#define COLNAME_NAME     0

#define COLNAME_DECLTYPE 1

#define COLNAME_DATABASE 2

#define COLNAME_TABLE    3

#define COLNAME_COLUMN   4

#ifdef SQLITE_ENABLE_COLUMN_METADATA

# define COLNAME_N        5      /* Number of COLNAME_xxx symbols */

#else

# ifdef SQLITE_OMIT_DECLTYPE

#   define COLNAME_N      1      /* Store only the name */

# else

#   define COLNAME_N      2      /* Store the name and decltype */

# endif

#endif

/*

** 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*);

int sqlite3VdbeAddOp0(Vdbe*,int);

int sqlite3VdbeAddOp1(Vdbe*,int,int);

int sqlite3VdbeAddOp2(Vdbe*,int,int,int);

int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);

int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);

int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);

void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);

void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);

void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);

void sqlite3VdbeChangeP5(Vdbe*, u8 P5);

void sqlite3VdbeJumpHere(Vdbe*, int addr);

void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);

void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);

void sqlite3VdbeUsesBtree(Vdbe*, int);

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*);

#ifdef SQLITE_DEBUG

  void sqlite3VdbeTrace(Vdbe*,FILE*);

#endif

void sqlite3VdbeResetStepResult(Vdbe*);

int sqlite3VdbeReset(Vdbe*);

void sqlite3VdbeSetNumCols(Vdbe*,int);

int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, int);

void sqlite3VdbeCountChanges(Vdbe*);

sqlite3 *sqlite3VdbeDb(Vdbe*);

void sqlite3VdbeSetSql(Vdbe*, const char *z, int n);

void sqlite3VdbeSwap(Vdbe*,Vdbe*);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

int sqlite3VdbeReleaseMemory(int);

#endif

UnpackedRecord *sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,

                                        UnpackedRecord*,int);

void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord*);

int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);

#ifndef NDEBUG

  void sqlite3VdbeComment(Vdbe*, const char*, ...);

# define VdbeComment(X)  sqlite3VdbeComment X

  void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);

# define VdbeNoopComment(X)  sqlite3VdbeNoopComment X

#else

# define VdbeComment(X)

# define VdbeNoopComment(X)

#endif

#endif