/*

 ** 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