**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.259 2006/06/11 23:41:55 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        assert( pParse->ckOffset>0 );
        sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
      }else if( pExpr->iColumn>=0 ){
        Table *pTab = pExpr->pTab;
        int iCol = pExpr->iColumn;

        sqlite3VdbeAddOp(v, OP_Column, pExpr->iTable, iCol);
        sqlite3ColumnDefault(v, pTab, iCol);
#ifndef SQLITE_OMIT_FLOATING_POINT
        if( pTab && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
          sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
        }
#endif
      }else{

        sqlite3VdbeAddOp(v, OP_Rowid, pExpr->iTable, 0);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, (char*)pExpr->token.z, pExpr->token.n);
      break;
    }

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.260 2006/06/13 01:04:52 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        assert( pParse->ckOffset>0 );
        sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
      }else if( pExpr->iColumn>=0 ){
        Table *pTab = pExpr->pTab;
        int iCol = pExpr->iColumn;
        sqlite3VdbeAddOp(v, pTab->isVirtual ? OP_VColumn : OP_Column,
                            pExpr->iTable, iCol);
        sqlite3ColumnDefault(v, pTab, iCol);
#ifndef SQLITE_OMIT_FLOATING_POINT
        if( pTab && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
          sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
        }
#endif
      }else{
        sqlite3VdbeAddOp(v, pExpr->pTab->isVirtual ? OP_VRowid : OP_Rowid,
                         pExpr->iTable, 0);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, (char*)pExpr->token.z, pExpr->token.n);
      break;
    }

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.170 2006/06/12 21:59:14 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  Each subclass will
** be taylored to the specific needs of the module implementation.   The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
*/
struct sqlite3_vtab {
  sqlite3_module *pModule;  /* The module for this virtual table */
  /* Virtual table implementations will typically add additional fields */
};

/* Every module implementation uses a subclass of the following structure
** to describe cursors that point into the virtual table and are used
** to loop through the virtual table.  Cursors are created using the
** xOpen method of the module.  Each module implementation will define

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.171 2006/06/13 01:04:53 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  Each subclass will
** be taylored to the specific needs of the module implementation.   The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
*/
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  /* Virtual table implementations will typically add additional fields */
};

/* Every module implementation uses a subclass of the following structure
** to describe cursors that point into the virtual table and are used
** to loop through the virtual table.  Cursors are created using the
** xOpen method of the module.  Each module implementation will define

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.5 2006/06/12 12:50:23 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

/*
** Global Tcl variable $echo_module is a list. This routine appends
** the string element zArg to that list in interpreter interp.
*/
static void appendToEchoModule(const sqlite3_module *pModule, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar((Tcl_Interp *)(pModule->pAux), "echo_module", zArg, flags);
}

static void appendToEchoTable(const sqlite3_vtab *pTab, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar((Tcl_Interp *)(pTab), "echo_module", zArg, flags);
}

/*
** This function is called from within the echo-modules xCreate and
** xConnect methods. The argc and argv arguments are copies of those 
** passed to the calling method. This function is responsible for
** calling sqlite3_declare_vtab() to declare the schema of the virtual
................................................................................
      rc = SQLITE_ERROR;
    }
    sqlite3_finalize(pStmt);
  }

  return rc;
}








/* Methods for the echo module */
static int echoCreate(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;
  *ppVtab = pModule->pAux;





  appendToEchoModule(pModule, "xCreate");
  for(i=0; i<argc; i++){
    appendToEchoModule(pModule, argv[i]);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoConnect(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;
  Tcl_Interp *interp = pModule->pAux;
  *ppVtab = pModule->pAux;





  Tcl_SetVar(interp, "echo_module", "xConnect", TCL_GLOBAL_ONLY);
  for(i=0; i<argc; i++){
    Tcl_SetVar(interp, "echo_module", argv[i],
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoDisconnect(sqlite3_vtab *pVtab){

  appendToEchoTable(pVtab, "xDisconnect");

  return 0;
}
static int echoDestroy(sqlite3_vtab *pVtab){
  Tcl_Interp *interp = (Tcl_Interp*)pVtab;
  Tcl_SetVar(interp, "echo_module", "xDestroy",
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  return 0;
}










/*
** A virtual table module that merely echos method calls into TCL
** variables.
*/
static sqlite3_module echoModule = {
  0,                         /* iVersion */
  "echo",                    /* zName */
  0,                         /* pAux */
  echoCreate,
  echoConnect,
  0,                         /* xBestIndex */
  echoDisconnect, 
  echoDestroy,
};

/*
** Decode a pointer to an sqlite3 object.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.6 2006/06/13 01:04:53 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

/*
** Global Tcl variable $echo_module is a list. This routine appends
** the string element zArg to that list in interpreter interp.
*/
static void appendToEchoModule(Tcl_Interp *interp, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar(interp, "echo_module", zArg, flags);
}

static void appendToEchoTable(Tcl_Interp *interp, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar(interp, "echo_module", zArg, flags);
}

/*
** This function is called from within the echo-modules xCreate and
** xConnect methods. The argc and argv arguments are copies of those 
** passed to the calling method. This function is responsible for
** calling sqlite3_declare_vtab() to declare the schema of the virtual
................................................................................
      rc = SQLITE_ERROR;
    }
    sqlite3_finalize(pStmt);
  }

  return rc;
}

/* An echo vtab object */
typedef struct echo_vtab echo_vtab;
struct echo_vtab {
  sqlite3_vtab base;
  Tcl_Interp *interp;
};

/* Methods for the echo module */
static int echoCreate(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;
  echo_vtab *pVtab;

  pVtab = sqliteMalloc( sizeof(*pVtab) );
  *ppVtab = &pVtab->base;
  pVtab->base.pModule = pModule;
  pVtab->interp = pModule->pAux;
  appendToEchoModule(pVtab->interp, "xCreate");
  for(i=0; i<argc; i++){
    appendToEchoModule(pVtab->interp, argv[i]);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoConnect(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;
  Tcl_Interp *interp = pModule->pAux;
  echo_vtab *pVtab;

  pVtab = sqliteMalloc( sizeof(*pVtab) );
  *ppVtab = &pVtab->base;
  pVtab->base.pModule = pModule;
  pVtab->interp = pModule->pAux;
  Tcl_SetVar(interp, "echo_module", "xConnect", TCL_GLOBAL_ONLY);
  for(i=0; i<argc; i++){
    Tcl_SetVar(interp, "echo_module", argv[i],
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoDisconnect(sqlite3_vtab *pVtab){
  echo_vtab *p = (echo_vtab*)pVtab;
  appendToEchoTable(p->interp, "xDisconnect");
  sqliteFree(pVtab);
  return 0;
}
static int echoDestroy(sqlite3_vtab *pVtab){
  echo_vtab *p = (echo_vtab*)pVtab;
  Tcl_SetVar(p->interp, "echo_module", "xDestroy",
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  return 0;
}

/*
** The xBestIndex method for the echo module always returns
** an index of 123.
*/
static int echoBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
  pIdxInfo->idxNum = 123;
  return SQLITE_OK;
}

/*
** A virtual table module that merely echos method calls into TCL
** variables.
*/
static sqlite3_module echoModule = {
  0,                         /* iVersion */
  "echo",                    /* zName */
  0,                         /* pAux */
  echoCreate,
  echoConnect,
  echoBestIndex,
  echoDisconnect, 
  echoDestroy,
};

/*
** Decode a pointer to an sqlite3 object.
*/

*************************************************************************
** 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 1.103 2006/06/11 23:41:56 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................
#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 */
#define P3_TRANSIENT (-9) /* P3 is a pointer to a transient string */


/* 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.

*************************************************************************
** 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 1.104 2006/06/13 01:04:53 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................
#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 */
#define P3_TRANSIENT (-9) /* P3 is a pointer to a transient string */
#define P3_VTAB     (-10) /* P3 is a pointer to an sqlite3_vtab 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.

      CollSeq *pColl = (CollSeq*)pOp->p3;
      sprintf(zTemp, "collseq(%.20s)", pColl->zName);
      zP3 = zTemp;
      break;
    }
    case P3_FUNCDEF: {
      FuncDef *pDef = (FuncDef*)pOp->p3;
      char zNum[30];
      sprintf(zTemp, "%.*s", nTemp, pDef->zName);
      sprintf(zNum,"(%d)", pDef->nArg);
      if( strlen(zTemp)+strlen(zNum)+1<=nTemp ){
        strcat(zTemp, zNum);
      }




      zP3 = zTemp;
      break;
    }

    default: {
      zP3 = pOp->p3;
      if( zP3==0 || pOp->opcode==OP_Noop ){
        zP3 = "";
      }
    }
  }

      CollSeq *pColl = (CollSeq*)pOp->p3;
      sprintf(zTemp, "collseq(%.20s)", pColl->zName);
      zP3 = zTemp;
      break;
    }
    case P3_FUNCDEF: {
      FuncDef *pDef = (FuncDef*)pOp->p3;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      zP3 = zTemp;
      break;


    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    case P3_VTAB: {
      sqlite3_vtab *pVtab = (sqlite3_vtab*)pOp->p3;
      sqlite3_snprintf(nTemp, zTemp, "%p:%s", pVtab, pVtab->pModule->zName);
      zP3 = zTemp;
      break;
    }
#endif
    default: {
      zP3 = pOp->p3;
      if( zP3==0 || pOp->opcode==OP_Noop ){
        zP3 = "";
      }
    }
  }

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.211 2006/06/12 21:59:14 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
  }
  memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
  pIdxInfo->idxNum = 0;
  pIdxInfo->orderByConsumed = 0;
  pIdxInfo->estimatedCost = SQLITE_BIG_DBL;
  nOrderBy = pIdxInfo->nOrderBy;
  if( pIdxInfo->nOrderBy && !orderByUsable ){
    *(int*)pIdxInfo->nOrderBy = 0;
  }
  pTab->pVtab->pModule->xBestIndex(pTab->pVtab, pIdxInfo);
  *(int*)pIdxInfo->nOrderBy = nOrderBy;
  return pIdxInfo->estimatedCost;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** Find the best index for accessing a particular table.  Return a pointer
** to the index, flags that describe how the index should be used, the
................................................................................
#endif /* SQLITE_OMIT_EXPLAIN */
    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pTab;
    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
    if( pTab->isEphem || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pIdxInfo ){
      sqlite3VdbeAddOp(v, OP_VOpen, 0, 0);  /***** Fix Me *****/
    }else
#endif
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, OP_OpenRead);
      if( pTab->nCol<(sizeof(Bitmask)*8) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
................................................................................
          if( pIdxInfo->aConstraintUsage[j].argvIndex==i ){
            sqlite3ExprCode(pParse, wc.a[j].pExpr->pRight);
            break;
          }
        }
        if( j==pIdxInfo->nConstraint ) break;
      }
      sqlite3VdbeAddOp(v, OP_VFilter, iCur, pIdxInfo->idxNum);
      if( i>1 ){
        sqlite3VdbeAddOp(v, OP_Pop, i-1, 0);
      }
      for(i=0; i<pIdxInfo->nConstraint; i++){
        if( pIdxInfo->aConstraintUsage[i].omit ){
          disableTerm(pLevel, &wc.a[i]);
        }
      }
      pLevel->op = OP_VNext;


    }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */

    if( pLevel->flags & WHERE_ROWID_EQ ){
      /* Case 1:  We can directly reference a single row using an
      **          equality comparison against the ROWID field.  Or
      **          we reference multiple rows using a "rowid IN (...)"

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.212 2006/06/13 01:04:53 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
  }
  memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
  pIdxInfo->idxNum = 0;
  pIdxInfo->orderByConsumed = 0;
  pIdxInfo->estimatedCost = SQLITE_BIG_DBL;
  nOrderBy = pIdxInfo->nOrderBy;
  if( pIdxInfo->nOrderBy && !orderByUsable ){
    *(int*)&pIdxInfo->nOrderBy = 0;
  }
  pTab->pVtab->pModule->xBestIndex(pTab->pVtab, pIdxInfo);
  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
  return pIdxInfo->estimatedCost;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** Find the best index for accessing a particular table.  Return a pointer
** to the index, flags that describe how the index should be used, the
................................................................................
#endif /* SQLITE_OMIT_EXPLAIN */
    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pTab;
    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
    if( pTab->isEphem || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pIdxInfo ){
      sqlite3VdbeOp3(v, OP_VOpen, 0, 0, (const char*)pTab->pVtab, P3_VTAB);
    }else
#endif
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, OP_OpenRead);
      if( pTab->nCol<(sizeof(Bitmask)*8) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
................................................................................
          if( pIdxInfo->aConstraintUsage[j].argvIndex==i ){
            sqlite3ExprCode(pParse, wc.a[j].pExpr->pRight);
            break;
          }
        }
        if( j==pIdxInfo->nConstraint ) break;
      }
      sqlite3VdbeAddOp(v, OP_Integer, i-1, 0);
      sqlite3VdbeAddOp(v, OP_Integer, pIdxInfo->idxNum, 0);
      sqlite3VdbeAddOp(v, OP_VFilter, iCur, brk);

      for(i=0; i<pIdxInfo->nConstraint; i++){
        if( pIdxInfo->aConstraintUsage[i].omit ){
          disableTerm(pLevel, &wc.a[i]);
        }
      }
      pLevel->op = OP_VNext;
      pLevel->p1 = iCur;
      pLevel->p2 = sqlite3VdbeCurrentAddr(v);
    }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */

    if( pLevel->flags & WHERE_ROWID_EQ ){
      /* Case 1:  We can directly reference a single row using an
      **          equality comparison against the ROWID field.  Or
      **          we reference multiple rows using a "rowid IN (...)"