**    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.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.41 2008/01/25 15:04:49 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( !createStat1 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }

  sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur, iRootPage, iDb);
  sqlite3VdbeChangeP5(v, createStat1);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, iStatCur, 3);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
................................................................................
    int regCol;       /* Content of a column from the table being analyzed */
    int regRowid;     /* Rowid for the inserted record */
    int regF2;

    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );


    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));
    nCol = pIdx->nColumn;
    regFields = iMem+nCol*2;
    regTemp = regRowid = regCol = regFields+3;
    regRec = regCol+1;
    if( regRec>pParse->nMem ){
      pParse->nMem = regRec;
    }
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, iIdxCur, nCol+1);

    /* Memory cells are used as follows:
    **
    **    mem[iMem]:             The total number of rows in the table.
    **    mem[iMem+1]:           Number of distinct values in column 1
    **    ...
    **    mem[iMem+nCol]:        Number of distinct values in column N

**    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.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.42 2008/03/25 09:47:35 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( !createStat1 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 3);
  sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur, iRootPage, iDb);
  sqlite3VdbeChangeP5(v, createStat1);

}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
................................................................................
    int regCol;       /* Content of a column from the table being analyzed */
    int regRowid;     /* Rowid for the inserted record */
    int regF2;

    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
    nCol = pIdx->nColumn;
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, nCol+1);
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));

    regFields = iMem+nCol*2;
    regTemp = regRowid = regCol = regFields+3;
    regRec = regCol+1;
    if( regRec>pParse->nMem ){
      pParse->nMem = regRec;
    }


    /* Memory cells are used as follows:
    **
    **    mem[iMem]:             The total number of rows in the table.
    **    mem[iMem+1]:           Number of distinct values in column 1
    **    ...
    **    mem[iMem+nCol]:        Number of distinct values in column N

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.443 2008/03/25 00:22:21 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
** 4:  There must be an active transaction.
**
** No checking is done to make sure that page iTable really is the
** root page of a b-tree.  If it is not, then the cursor acquired
** will not work correctly.
*/
static int btreeCursor(
  Btree *p,                       /* The btree */
  int iTable,                     /* Root page of table to open */
  int wrFlag,                     /* 1 to write. 0 read-only */
  struct KeyInfo *pKeyInfo,       /* First arg to comparison function */
  BtCursor **ppCur                /* Write new cursor here */
){
  int rc;
  BtCursor *pCur;
  BtShared *pBt = p->pBt;

  assert( sqlite3BtreeHoldsMutex(p) );
  *ppCur = 0;
  if( wrFlag ){
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(p, iTable, 0) ){
      return SQLITE_LOCKED;
    }
................................................................................
    if( rc!=SQLITE_OK ){
      return rc;
    }
    if( pBt->readOnly && wrFlag ){
      return SQLITE_READONLY;
    }
  }
  pCur = sqlite3MallocZero( sizeof(*pCur) );
  if( pCur==0 ){
    rc = SQLITE_NOMEM;
    goto create_cursor_exception;
  }
  pCur->pgnoRoot = (Pgno)iTable;
  if( iTable==1 && sqlite3PagerPagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    goto create_cursor_exception;
  }
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  if( rc!=SQLITE_OK ){
................................................................................
  pCur->wrFlag = wrFlag;
  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }
  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;
  *ppCur = pCur;

  return SQLITE_OK;

create_cursor_exception:
  if( pCur ){
    releasePage(pCur->pPage);
    sqlite3_free(pCur);
  }
  unlockBtreeIfUnused(pBt);
  return rc;
}
int sqlite3BtreeCursor(
  Btree *p,                   /* The btree */
  int iTable,                 /* Root page of table to open */
  int wrFlag,                 /* 1 to write. 0 read-only */
  struct KeyInfo *pKeyInfo,   /* First arg to xCompare() */
  BtCursor **ppCur            /* Write new cursor here */
){
  int rc;
  sqlite3BtreeEnter(p);
  p->pBt->db = p->db;
  rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, ppCur);
  sqlite3BtreeLeave(p);
  return rc;
}






/*
** Close a cursor.  The read lock on the database file is released
** when the last cursor is closed.
*/
int sqlite3BtreeCloseCursor(BtCursor *pCur){
  BtShared *pBt = pCur->pBt;
  Btree *pBtree = pCur->pBtree;



  sqlite3BtreeEnter(pBtree);
  pBt->db = pBtree->db;
  clearCursorPosition(pCur);
  if( pCur->pPrev ){
    pCur->pPrev->pNext = pCur->pNext;
  }else{
    pBt->pCursor = pCur->pNext;
  }
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur->pPrev;
  }
  releasePage(pCur->pPage);
  unlockBtreeIfUnused(pBt);
  invalidateOverflowCache(pCur);
  sqlite3_free(pCur);
  sqlite3BtreeLeave(pBtree);

  return SQLITE_OK;
}

/*
** Make a temporary cursor by filling in the fields of pTempCur.
** The temporary cursor is not on the cursor list for the Btree.
*/

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.444 2008/03/25 09:47:35 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
** 4:  There must be an active transaction.
**
** No checking is done to make sure that page iTable really is the
** root page of a b-tree.  If it is not, then the cursor acquired
** will not work correctly.
*/
static int btreeCursor(
  Btree *p,                              /* The btree */
  int iTable,                            /* Root page of table to open */
  int wrFlag,                            /* 1 to write. 0 read-only */
  struct KeyInfo *pKeyInfo,              /* First arg to comparison function */
  BtCursor *pCur                         /* Space for new cursor */
){
  int rc;

  BtShared *pBt = p->pBt;

  assert( sqlite3BtreeHoldsMutex(p) );

  if( wrFlag ){
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(p, iTable, 0) ){
      return SQLITE_LOCKED;
    }
................................................................................
    if( rc!=SQLITE_OK ){
      return rc;
    }
    if( pBt->readOnly && wrFlag ){
      return SQLITE_READONLY;
    }
  }





  pCur->pgnoRoot = (Pgno)iTable;
  if( iTable==1 && sqlite3PagerPagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    goto create_cursor_exception;
  }
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  if( rc!=SQLITE_OK ){
................................................................................
  pCur->wrFlag = wrFlag;
  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }
  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;


  return SQLITE_OK;

create_cursor_exception:
  if( pCur ){
    releasePage(pCur->pPage);

  }
  unlockBtreeIfUnused(pBt);
  return rc;
}
int sqlite3BtreeCursor(
  Btree *p,                                   /* The btree */
  int iTable,                                 /* Root page of table to open */
  int wrFlag,                                 /* 1 to write. 0 read-only */
  struct KeyInfo *pKeyInfo,                   /* First arg to xCompare() */
  BtCursor *pCur                              /* Write new cursor here */
){
  int rc;
  sqlite3BtreeEnter(p);
  p->pBt->db = p->db;
  rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
  sqlite3BtreeLeave(p);
  return rc;
}
int sqlite3BtreeCursorSize(){
  return sizeof(BtCursor);
}



/*
** Close a cursor.  The read lock on the database file is released
** when the last cursor is closed.
*/
int sqlite3BtreeCloseCursor(BtCursor *pCur){

  Btree *pBtree = pCur->pBtree;

  if( pBtree ){
    BtShared *pBt = pCur->pBt;
    sqlite3BtreeEnter(pBtree);
    pBt->db = pBtree->db;
    clearCursorPosition(pCur);
    if( pCur->pPrev ){
      pCur->pPrev->pNext = pCur->pNext;
    }else{
      pBt->pCursor = pCur->pNext;
    }
    if( pCur->pNext ){
      pCur->pNext->pPrev = pCur->pPrev;
    }
    releasePage(pCur->pPage);
    unlockBtreeIfUnused(pBt);
    invalidateOverflowCache(pCur);
    /* sqlite3_free(pCur); */
    sqlite3BtreeLeave(pBtree);
  }
  return SQLITE_OK;
}

/*
** Make a temporary cursor by filling in the fields of pTempCur.
** The temporary cursor is not on the cursor list for the Btree.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.95 2008/03/25 00:22:21 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
................................................................................
int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int);
int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
void sqlite3BtreeTripAllCursors(Btree*, int);

int sqlite3BtreeCursor(
  Btree*,                  /* BTree containing table to open */
  int iTable,              /* Index of root page */
  int wrFlag,              /* 1 for writing.  0 for read-only */
  struct KeyInfo*,         /* First argument to compare function */
  BtCursor **ppCursor      /* Returned cursor */
);


int sqlite3BtreeCloseCursor(BtCursor*);
int sqlite3BtreeMoveto(BtCursor*,const void *pKey,i64 nKey,int bias,int *pRes);
int sqlite3BtreeDelete(BtCursor*);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.96 2008/03/25 09:47:35 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
................................................................................
int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int);
int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
void sqlite3BtreeTripAllCursors(Btree*, int);

int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */
  int wrFlag,                          /* 1 for writing.  0 for read-only */
  struct KeyInfo*,                     /* First argument to compare function */
  BtCursor *pCursor                    /* Space to write cursor structure */
);
int sqlite3BtreeCursorSize();

int sqlite3BtreeCloseCursor(BtCursor*);
int sqlite3BtreeMoveto(BtCursor*,const void *pKey,i64 nKey,int bias,int *pRes);
int sqlite3BtreeDelete(BtCursor*);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias);

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.475 2008/03/20 14:03:29 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));

  sqlite3VdbeAddOp3(v, OP_OpenWrite, 0, MASTER_ROOT, iDb);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 5); /* sqlite_master has 5 columns */
}

/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db 
** does not exist.

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.476 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 5);/* sqlite_master has 5 columns */
  sqlite3VdbeAddOp3(v, OP_OpenWrite, 0, MASTER_ROOT, iDb);

}

/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db 
** does not exist.

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.162 2008/03/19 20:42:14 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  if( IsVirtual(pTab) ) return;
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);

  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
  VdbeComment((v, "%s", pTab->zName));
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, iCur, pTab->nCol);
}


#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
/*
** Evaluate a view and store its result in an ephemeral table.  The
** pWhere argument is an optional WHERE clause that restricts the
................................................................................
    /* End the database scan loop.
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( triggers_exist ){

      sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    end = sqlite3VdbeMakeLabel(v);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.163 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  if( IsVirtual(pTab) ) return;
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
  VdbeComment((v, "%s", pTab->zName));

}


#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
/*
** Evaluate a view and store its result in an ephemeral table.  The
** pWhere argument is an optional WHERE clause that restricts the
................................................................................
    /* End the database scan loop.
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( triggers_exist ){
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
      sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);

    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    end = sqlite3VdbeMakeLabel(v);

**    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 1.356 2008/03/20 16:30:18 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
          sqlite3VdbeUsesBtree(v, iDb);

          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
  

          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                               pKey,P4_KEYINFO_HANDOFF);
          VdbeComment((v, "%s", pIdx->zName));
          eType = IN_INDEX_INDEX;
          sqlite3VdbeAddOp2(v, OP_SetNumColumns, iTab, pIdx->nColumn);

          sqlite3VdbeJumpHere(v, iAddr);
        }
      }
    }
  }

................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp1(v, OP_OpenEphemeral, pExpr->iTable);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, pExpr->iTable, 1);

      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */

**    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 1.357 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
          sqlite3VdbeUsesBtree(v, iDb);

          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
  
          sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIdx->nColumn);
          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                               pKey,P4_KEYINFO_HANDOFF);
          VdbeComment((v, "%s", pIdx->zName));
          eType = IN_INDEX_INDEX;


          sqlite3VdbeJumpHere(v, iAddr);
        }
      }
    }
  }

................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;


      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.232 2008/03/19 20:42:14 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
      sqlite3ReleaseTempReg(pParse, regRowid);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeJumpHere(v, iInitCode);
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, 0);
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, srcTab, nColumn);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
      sqlite3VdbeResolveLabel(v, iCleanup);
    }else{
      sqlite3VdbeJumpHere(v, iInitCode);
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
................................................................................
  if( pColumn==0 && nColumn>0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( triggers_exist ){

    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, newIdx, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    regRowCount = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.233 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
      sqlite3ReleaseTempReg(pParse, regRowid);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeJumpHere(v, iInitCode);
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);

      sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
      sqlite3VdbeResolveLabel(v, iCleanup);
    }else{
      sqlite3VdbeJumpHere(v, iInitCode);
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
................................................................................
  if( pColumn==0 && nColumn>0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( triggers_exist ){
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);

  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    regRowCount = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.81 2008/03/25 00:22:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  */
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && iDb==1 ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
    }
    return SQLITE_OK;
  }





  sqlite3BtreeEnter(pDb->pBt);
  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, &curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
    sqlite3BtreeLeave(pDb->pBt);
    goto error_out;
  }

  /* Get the database meta information.
  **
  ** Meta values are as follows:
  **    meta[0]   Schema cookie.  Changes with each schema change.
  **    meta[1]   File format of schema layer.
................................................................................
  if( rc==SQLITE_OK ){
    int i;
    for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
    }
    if( rc ){
      sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
      sqlite3BtreeCloseCursor(curMain);
      sqlite3BtreeLeave(pDb->pBt);
      goto error_out;
    }
  }else{
    memset(meta, 0, sizeof(meta));
  }
  pDb->pSchema->schema_cookie = meta[0];

  /* If opening a non-empty database, check the text encoding. For the
................................................................................
    if( iDb==0 ){
      /* If opening the main database, set ENC(db). */
      ENC(db) = (u8)meta[4];
      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */
      if( meta[4]!=ENC(db) ){
        sqlite3BtreeCloseCursor(curMain);
        sqlite3SetString(pzErrMsg, "attached databases must use the same"
            " text encoding as main database", (char*)0);
        sqlite3BtreeLeave(pDb->pBt);
        return SQLITE_ERROR;

      }
    }
  }else{
    DbSetProperty(db, iDb, DB_Empty);
  }
  pDb->pSchema->enc = ENC(db);

................................................................................
  ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants
  */
  pDb->pSchema->file_format = meta[1];
  if( pDb->pSchema->file_format==0 ){
    pDb->pSchema->file_format = 1;
  }
  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
    sqlite3BtreeCloseCursor(curMain);
    sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
    sqlite3BtreeLeave(pDb->pBt);
    return SQLITE_ERROR;

  }

  /* Ticket #2804:  When we open a database in the newer file format,
  ** clear the legacy_file_format pragma flag so that a VACUUM will
  ** not downgrade the database and thus invalidate any descending
  ** indices that the user might have created.
  */
................................................................................
    (void)sqlite3SafetyOn(db);
    sqlite3_free(zSql);
#ifndef SQLITE_OMIT_ANALYZE
    if( rc==SQLITE_OK ){
      sqlite3AnalysisLoad(db, iDb);
    }
#endif
    sqlite3BtreeCloseCursor(curMain);
  }
  if( db->mallocFailed ){
    /* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */
    rc = SQLITE_NOMEM;
    sqlite3ResetInternalSchema(db, 0);
  }
  if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
................................................................................
    ** of the schema was loaded before the error occured. The primary
    ** purpose of this is to allow access to the sqlite_master table
    ** even when its contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }








  sqlite3BtreeLeave(pDb->pBt);

error_out:
  if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
    db->mallocFailed = 1;
  }
  return rc;
................................................................................
static int schemaIsValid(sqlite3 *db){
  int iDb;
  int rc;
  BtCursor *curTemp;
  int cookie;
  int allOk = 1;



  assert( sqlite3_mutex_held(db->mutex) );
  for(iDb=0; allOk && iDb<db->nDb; iDb++){
    Btree *pBt;
    pBt = db->aDb[iDb].pBt;
    if( pBt==0 ) continue;

    rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, &curTemp);
    if( rc==SQLITE_OK ){
      rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
      if( rc==SQLITE_OK && cookie!=db->aDb[iDb].pSchema->schema_cookie ){
        allOk = 0;
      }
      sqlite3BtreeCloseCursor(curTemp);
    }
    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
      db->mallocFailed = 1;
    }
  }






  return allOk;
}

/*
** Convert a schema pointer into the iDb index that indicates
** which database file in db->aDb[] the schema refers to.
**

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.82 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  */
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && iDb==1 ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
    }
    return SQLITE_OK;
  }
  curMain = sqlite3MallocZero(sqlite3BtreeCursorSize());
  if( !curMain ){
    rc = SQLITE_NOMEM;
    goto error_out;
  }
  sqlite3BtreeEnter(pDb->pBt);
  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);

    goto leave_error_out;
  }

  /* Get the database meta information.
  **
  ** Meta values are as follows:
  **    meta[0]   Schema cookie.  Changes with each schema change.
  **    meta[1]   File format of schema layer.
................................................................................
  if( rc==SQLITE_OK ){
    int i;
    for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
    }
    if( rc ){
      sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);


      goto leave_error_out;
    }
  }else{
    memset(meta, 0, sizeof(meta));
  }
  pDb->pSchema->schema_cookie = meta[0];

  /* If opening a non-empty database, check the text encoding. For the
................................................................................
    if( iDb==0 ){
      /* If opening the main database, set ENC(db). */
      ENC(db) = (u8)meta[4];
      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */
      if( meta[4]!=ENC(db) ){

        sqlite3SetString(pzErrMsg, "attached databases must use the same"
            " text encoding as main database", (char*)0);

        rc = SQLITE_ERROR;
        goto leave_error_out;
      }
    }
  }else{
    DbSetProperty(db, iDb, DB_Empty);
  }
  pDb->pSchema->enc = ENC(db);

................................................................................
  ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants
  */
  pDb->pSchema->file_format = meta[1];
  if( pDb->pSchema->file_format==0 ){
    pDb->pSchema->file_format = 1;
  }
  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){

    sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);

    rc = SQLITE_ERROR;
    goto leave_error_out;
  }

  /* Ticket #2804:  When we open a database in the newer file format,
  ** clear the legacy_file_format pragma flag so that a VACUUM will
  ** not downgrade the database and thus invalidate any descending
  ** indices that the user might have created.
  */
................................................................................
    (void)sqlite3SafetyOn(db);
    sqlite3_free(zSql);
#ifndef SQLITE_OMIT_ANALYZE
    if( rc==SQLITE_OK ){
      sqlite3AnalysisLoad(db, iDb);
    }
#endif

  }
  if( db->mallocFailed ){
    /* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */
    rc = SQLITE_NOMEM;
    sqlite3ResetInternalSchema(db, 0);
  }
  if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
................................................................................
    ** of the schema was loaded before the error occured. The primary
    ** purpose of this is to allow access to the sqlite_master table
    ** even when its contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }

  /* Jump here for an error that occurs after successfully allocating
  ** curMain and calling sqlite3BtreeEnter(). For an error that occurs
  ** before that point, jump to error_out.
  */
leave_error_out:
  sqlite3BtreeCloseCursor(curMain);
  sqlite3_free(curMain);
  sqlite3BtreeLeave(pDb->pBt);

error_out:
  if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
    db->mallocFailed = 1;
  }
  return rc;
................................................................................
static int schemaIsValid(sqlite3 *db){
  int iDb;
  int rc;
  BtCursor *curTemp;
  int cookie;
  int allOk = 1;

  curTemp = (BtCursor *)sqlite3_malloc(sqlite3BtreeCursorSize());
  if( curTemp ){
    assert( sqlite3_mutex_held(db->mutex) );
    for(iDb=0; allOk && iDb<db->nDb; iDb++){
      Btree *pBt;
      pBt = db->aDb[iDb].pBt;
      if( pBt==0 ) continue;
      memset(curTemp, 0, sqlite3BtreeCursorSize());
      rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, curTemp);
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
        if( rc==SQLITE_OK && cookie!=db->aDb[iDb].pSchema->schema_cookie ){
          allOk = 0;
        }
        sqlite3BtreeCloseCursor(curTemp);
      }
      if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
        db->mallocFailed = 1;
      }
    }
    sqlite3_free(curTemp);
  }else{
    allOk = 0;
    db->mallocFailed = 1;
  }

  return allOk;
}

/*
** Convert a schema pointer into the iDb index that indicates
** which database file in db->aDb[] the schema refers to.
**

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.417 2008/03/22 01:07:18 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................

  int regRow;
  int regRowid;

  iTab = pOrderBy->iECursor;
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    pseudoTab = pParse->nTab++;

    sqlite3VdbeAddOp2(v, OP_OpenPseudo, pseudoTab, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, pseudoTab, nColumn);
  }
  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, brk);
  codeOffset(v, p, cont);
  regRow = sqlite3GetTempReg(pParse);
  regRowid = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow);
  switch( eDest ){
................................................................................
      /* If there is a GROUP BY clause we might need a sorting index to
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OpenEphemeral instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
      addrSortingIdx =
          sqlite3VdbeAddOp4(v, OP_OpenEphemeral, sAggInfo.sortingIdx,
                         sAggInfo.nSortingColumn, 0,
                         (char*)pKeyInfo, P4_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = ++pParse->nMem;
      iAbortFlag = ++pParse->nMem;
      iAMem = pParse->nMem + 1;
      pParse->nMem += pGroupBy->nExpr;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.418 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................

  int regRow;
  int regRowid;

  iTab = pOrderBy->iECursor;
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, nColumn);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, pseudoTab, 0);

  }
  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, brk);
  codeOffset(v, p, cont);
  regRow = sqlite3GetTempReg(pParse);
  regRowid = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow);
  switch( eDest ){
................................................................................
      /* If there is a GROUP BY clause we might need a sorting index to
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OpenEphemeral instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);

      addrSortingIdx = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, 
          sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
          0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = ++pParse->nMem;
      iAbortFlag = ++pParse->nMem;
      iAMem = pParse->nMem + 1;
      pParse->nMem += pGroupBy->nExpr;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.92 2008/03/25 00:22:21 drh Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

................................................................................
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM WRITEABLE\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  if( Tcl_GetBoolean(interp, argv[3], &wrFlag) ) return TCL_ERROR;


  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCursor(pBt, iTable, wrFlag, 0, &pCur);
  sqlite3BtreeLeave(pBt);
  if( rc ){

    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf), zBuf,"%p", pCur);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;
}
................................................................................
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  pBt = pCur->pBtree;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCloseCursor(pCur);
  sqlite3BtreeLeave(pBt);

  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return SQLITE_OK;
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.93 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

................................................................................
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM WRITEABLE\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  if( Tcl_GetBoolean(interp, argv[3], &wrFlag) ) return TCL_ERROR;
  pCur = (BtCursor *)ckalloc(sqlite3BtreeCursorSize());
  memset(pCur, 0, sqlite3BtreeCursorSize());
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCursor(pBt, iTable, wrFlag, 0, pCur);
  sqlite3BtreeLeave(pBt);
  if( rc ){
    ckfree((char *)pCur);
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf), zBuf,"%p", pCur);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;
}
................................................................................
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  pBt = pCur->pBtree;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCloseCursor(pCur);
  sqlite3BtreeLeave(pBt);
  ckfree((char *)pCur);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return SQLITE_OK;
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.18 2008/03/21 14:22:44 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
    extern int sqlite3MemdebugSettitle(const char*);
    sqlite3MemdebugSettitle(zTitle);
  }
#endif
  return TCL_OK;
}

#define MALLOC_LOG_FRAMES 5
static Tcl_HashTable aMallocLog;
static int mallocLogEnabled = 0;

typedef struct MallocLog MallocLog;
struct MallocLog {
  int nCall;
  int nByte;

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.19 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
    extern int sqlite3MemdebugSettitle(const char*);
    sqlite3MemdebugSettitle(zTitle);
  }
#endif
  return TCL_OK;
}

#define MALLOC_LOG_FRAMES 10 
static Tcl_HashTable aMallocLog;
static int mallocLogEnabled = 0;

typedef struct MallocLog MallocLog;
struct MallocLog {
  int nCall;
  int nByte;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.172 2008/03/19 20:42:14 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
  /* Generate the code for triggers.
  */
  if( triggers_exist ){
    int iGoto;

    /* Create pseudo-tables for NEW and OLD
    */

    sqlite3VdbeAddOp2(v, OP_OpenPseudo, oldIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, newIdx, pTab->nCol);

    iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.173 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
  /* Generate the code for triggers.
  */
  if( triggers_exist ){
    int iGoto;

    /* Create pseudo-tables for NEW and OLD
    */
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, oldIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);


    iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.716 2008/03/25 00:22:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  return (opcodeProperty[opcode]&mask)!=0;
}

/*
** Allocate cursor number iCur.  Return a pointer to it.  Return NULL
** if we run out of memory.
*/
static Cursor *allocateCursor(Vdbe *p, int iCur, int iDb){


























  Cursor *pCx;
















  assert( iCur<p->nCursor );
  if( p->apCsr[iCur] ){
    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);

  }

  p->apCsr[iCur] = pCx = sqlite3MallocZero( sizeof(Cursor) );
  if( pCx ){

    pCx->iDb = iDb;







  }
  return pCx;
}

/*
** Try to convert a value into a numeric representation if we can
** do so without loss of information.  In other words, if the string
................................................................................
case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
  if( (pIn1->flags & MEM_Null)==0 ){
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: SetNumColumns P1 P2 * * *
**
** Before the OP_Column opcode can be executed on a cursor, this
** opcode must be called to set the number of fields in the table.
**
** This opcode sets the number of columns for cursor P1 to P2.

**
** If OP_KeyAsData is to be applied to cursor P1, it must be executed
** before this op-code.






*/
case OP_SetNumColumns: {
  Cursor *pC;
  assert( (pOp->p1)<p->nCursor );
  assert( p->apCsr[pOp->p1]!=0 );
  pC = p->apCsr[pOp->p1];
  pC->nField = pOp->p2;
  break;
}

/* Opcode: Column P1 P2 P3 P4 *
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
................................................................................
  }

  assert( p2<nField );

  /* Read and parse the table header.  Store the results of the parse
  ** into the record header cache fields of the cursor.
  */
  if( pC->cacheStatus==p->cacheCtr ){
    aType = pC->aType;

    aOffset = pC->aOffset;
  }else{
    u8 *zIdx;        /* Index into header */
    u8 *zEndHdr;     /* Pointer to first byte after the header */
    u32 offset;      /* Offset into the data */
    int szHdrSz;     /* Size of the header size field at start of record */
    int avail;       /* Number of bytes of available data */

    aType = pC->aType;
    if( aType==0 ){
      pC->aType = aType = sqlite3DbMallocRaw(db, 2*nField*sizeof(aType) );
    }
    if( aType==0 ){
      goto no_mem;
    }
    pC->aOffset = aOffset = &aType[nField];
    pC->payloadSize = payloadSize;
    pC->cacheStatus = p->cacheCtr;

    /* Figure out how many bytes are in the header */
    if( zRec ){
      zData = zRec;
................................................................................
    assert( p2<=p->nMem );
    pIn2 = &p->aMem[p2];
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = pIn2->u.i;
    assert( p2>=2 );
  }
  assert( i>=0 );
  pCur = allocateCursor(p, i, iDb);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, &pCur->pCursor);
  if( pOp->p4type==P4_KEYINFO ){
    pCur->pKeyInfo = pOp->p4.pKeyInfo;
    pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
    pCur->pKeyInfo->enc = ENC(p->db);
  }else{
    pCur->pKeyInfo = 0;
    pCur->pIncrKey = &pCur->bogusIncrKey;
................................................................................
        goto abort_due_to_error;
      }
      break;
    }
    case SQLITE_EMPTY: {
      pCur->isTable = pOp->p4type!=P4_KEYINFO;
      pCur->isIndex = !pCur->isTable;

      rc = SQLITE_OK;
      break;
    }
    default: {
      goto abort_due_to_error;
    }
  }
................................................................................
      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;

  assert( i>=0 );
  pCx = allocateCursor(p, i, -1);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  rc = sqlite3BtreeFactory(db, 0, 1, SQLITE_DEFAULT_TEMP_CACHE_SIZE, openFlags,
                           &pCx->pBt);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
  }
................................................................................
    if( pOp->p4.pKeyInfo ){
      int pgno;
      assert( pOp->p4type==P4_KEYINFO );
      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA); 
      if( rc==SQLITE_OK ){
        assert( pgno==MASTER_ROOT+1 );
        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, 
                                (KeyInfo*)pOp->p4.z, &pCx->pCursor);
        pCx->pKeyInfo = pOp->p4.pKeyInfo;
        pCx->pKeyInfo->enc = ENC(p->db);
        pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
      }
      pCx->isTable = 0;
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, &pCx->pCursor);
      pCx->isTable = 1;
      pCx->pIncrKey = &pCx->bogusIncrKey;
    }
  }
  pCx->nField = pOp->p2;
  pCx->isIndex = !pCx->isTable;
  break;
}

/* Opcode: OpenPseudo P1 * * * *
**
** Open a new cursor that points to a fake table that contains a single
................................................................................
** row output from the sorter so that the row can be decomposed into
** individual columns using the OP_Column opcode.
*/
case OP_OpenPseudo: {
  int i = pOp->p1;
  Cursor *pCx;
  assert( i>=0 );
  pCx = allocateCursor(p, i, -1);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->pseudoTable = 1;
  pCx->pIncrKey = &pCx->bogusIncrKey;
  pCx->isTable = 1;
  pCx->isIndex = 0;
  break;
................................................................................
  rc = pModule->xOpen(pVtab, &pVtabCursor);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( SQLITE_OK==rc ){
    /* Initialise sqlite3_vtab_cursor base class */
    pVtabCursor->pVtab = pVtab;

    /* Initialise vdbe cursor object */
    pCur = allocateCursor(p, pOp->p1, -1);
    if( pCur ){
      pCur->pVtabCursor = pVtabCursor;
      pCur->pModule = pVtabCursor->pVtab->pModule;
    }else{
      db->mallocFailed = 1;
      pModule->xClose(pVtabCursor);
    }

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.717 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  return (opcodeProperty[opcode]&mask)!=0;
}

/*
** Allocate cursor number iCur.  Return a pointer to it.  Return NULL
** if we run out of memory.
*/
static Cursor *allocateCursor(
  Vdbe *p, 
  int iCur, 
  Op *pOp,
  int iDb, 
  int isBtreeCursor
){
  /* Find the memory cell that will be used to store the blob of memory
  ** required for this Cursor structure. It is convenient to use a 
  ** vdbe memory cell to manage the memory allocation required for a
  ** Cursor structure for the following reasons:
  **
  **   * Sometimes cursor numbers are used for a couple of different
  **     purposes in a vdbe program. The different uses might require
  **     different sized allocations. Memory cells provide growable
  **     allocations.
  **
  **   * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can
  **     be freed lazily via the sqlite3_release_memory() API. This
  **     minimizes the number of malloc calls made by the system.
  **
  ** Memory cells for cursors are allocated at the top of the address
  ** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
  ** cursor 1 is managed by memory cell (p->nMem-1), etc.
  */
  Mem *pMem = &p->aMem[p->nMem-iCur];

  Cursor *pCx = 0;
  /* If the opcode of pOp is OP_SetNumColumns, then pOp->p2 contains
  ** the number of fields in the records contained in the table or
  ** index being opened. Use this to reserve space for the 
  ** Cursor.aType[] array.
  */
  int nField = 0;
  if( pOp->opcode==OP_SetNumColumns || pOp->opcode==OP_OpenEphemeral ){
    nField = pOp->p2;
  }


  int nByte = 
      sizeof(Cursor) + 
      (isBtreeCursor?sqlite3BtreeCursorSize():0) + 
      2*nField*sizeof(u32);

  assert( iCur<p->nCursor );
  if( p->apCsr[iCur] ){
    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
    p->apCsr[iCur] = 0;
  }
  if( SQLITE_OK==sqlite3VdbeMemGrow(pMem, nByte, 0) ){
    p->apCsr[iCur] = pCx = (Cursor *)pMem->z;

    memset(pMem->z, 0, nByte);
    pCx->iDb = iDb;
    pCx->nField = nField;
    if( nField ){
      pCx->aType = (u32 *)&pMem->z[sizeof(Cursor)];
    }
    if( isBtreeCursor ){
      pCx->pCursor = (BtCursor *)&pMem->z[sizeof(Cursor)+2*nField*sizeof(u32)];
    }
  }
  return pCx;
}

/*
** Try to convert a value into a numeric representation if we can
** do so without loss of information.  In other words, if the string
................................................................................
case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
  if( (pIn1->flags & MEM_Null)==0 ){
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: SetNumColumns * P2 * * *
**
** This opcode sets the number of columns for the cursor opened by the
** following instruction to P2.
**
** An OP_SetNumColumns is only useful if it occurs immediately before 
** one of the following opcodes:
**

**     OpenRead
**     OpenWrite
**     OpenPseudo
**
** If the OP_Column opcode is to be executed on a cursor, then
** this opcode must be present immediately before the opcode that
** opens the cursor.
*/
case OP_SetNumColumns: {





  break;
}

/* Opcode: Column P1 P2 P3 P4 *
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
................................................................................
  }

  assert( p2<nField );

  /* Read and parse the table header.  Store the results of the parse
  ** into the record header cache fields of the cursor.
  */

  aType = pC->aType;
  if( pC->cacheStatus==p->cacheCtr ){
    aOffset = pC->aOffset;
  }else{
    u8 *zIdx;        /* Index into header */
    u8 *zEndHdr;     /* Pointer to first byte after the header */
    u32 offset;      /* Offset into the data */
    int szHdrSz;     /* Size of the header size field at start of record */
    int avail;       /* Number of bytes of available data */

    assert(aType);






    pC->aOffset = aOffset = &aType[nField];
    pC->payloadSize = payloadSize;
    pC->cacheStatus = p->cacheCtr;

    /* Figure out how many bytes are in the header */
    if( zRec ){
      zData = zRec;
................................................................................
    assert( p2<=p->nMem );
    pIn2 = &p->aMem[p2];
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = pIn2->u.i;
    assert( p2>=2 );
  }
  assert( i>=0 );
  pCur = allocateCursor(p, i, &pOp[-1], iDb, 1);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, pCur->pCursor);
  if( pOp->p4type==P4_KEYINFO ){
    pCur->pKeyInfo = pOp->p4.pKeyInfo;
    pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
    pCur->pKeyInfo->enc = ENC(p->db);
  }else{
    pCur->pKeyInfo = 0;
    pCur->pIncrKey = &pCur->bogusIncrKey;
................................................................................
        goto abort_due_to_error;
      }
      break;
    }
    case SQLITE_EMPTY: {
      pCur->isTable = pOp->p4type!=P4_KEYINFO;
      pCur->isIndex = !pCur->isTable;
      pCur->pCursor = 0;
      rc = SQLITE_OK;
      break;
    }
    default: {
      goto abort_due_to_error;
    }
  }
................................................................................
      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;

  assert( i>=0 );
  pCx = allocateCursor(p, i, pOp, -1, 1);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  rc = sqlite3BtreeFactory(db, 0, 1, SQLITE_DEFAULT_TEMP_CACHE_SIZE, openFlags,
                           &pCx->pBt);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
  }
................................................................................
    if( pOp->p4.pKeyInfo ){
      int pgno;
      assert( pOp->p4type==P4_KEYINFO );
      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA); 
      if( rc==SQLITE_OK ){
        assert( pgno==MASTER_ROOT+1 );
        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, 
                                (KeyInfo*)pOp->p4.z, pCx->pCursor);
        pCx->pKeyInfo = pOp->p4.pKeyInfo;
        pCx->pKeyInfo->enc = ENC(p->db);
        pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
      }
      pCx->isTable = 0;
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
      pCx->isTable = 1;
      pCx->pIncrKey = &pCx->bogusIncrKey;
    }
  }

  pCx->isIndex = !pCx->isTable;
  break;
}

/* Opcode: OpenPseudo P1 * * * *
**
** Open a new cursor that points to a fake table that contains a single
................................................................................
** row output from the sorter so that the row can be decomposed into
** individual columns using the OP_Column opcode.
*/
case OP_OpenPseudo: {
  int i = pOp->p1;
  Cursor *pCx;
  assert( i>=0 );
  pCx = allocateCursor(p, i, &pOp[-1], -1, 0);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->pseudoTable = 1;
  pCx->pIncrKey = &pCx->bogusIncrKey;
  pCx->isTable = 1;
  pCx->isIndex = 0;
  break;
................................................................................
  rc = pModule->xOpen(pVtab, &pVtabCursor);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( SQLITE_OK==rc ){
    /* Initialise sqlite3_vtab_cursor base class */
    pVtabCursor->pVtab = pVtab;

    /* Initialise vdbe cursor object */
    pCur = allocateCursor(p, pOp->p1, &pOp[-1], -1, 0);
    if( pCur ){
      pCur->pVtabCursor = pVtabCursor;
      pCur->pModule = pVtabCursor->pVtab->pModule;
    }else{
      db->mallocFailed = 1;
      pModule->xClose(pVtabCursor);
    }

  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. This
   * is because the call to resizeOpArray() below may shrink the
   * p->aOp[] array to save memory if called when in VDBE_MAGIC_RUN 
   * state.
   */
  p->magic = VDBE_MAGIC_RUN;












  /*
  ** Allocation space for registers.
  */
  if( p->aMem==0 ){
    int nArg;       /* Maximum number of args passed to a user function. */
    resolveP2Values(p, &nArg);
    resizeOpArray(p, p->nOp);
................................................................................
      p->aOp[i].cycles = 0;
    }
  }
#endif
}

/*
** Close a VDBE cursor and release all the resources that cursor happens
** to hold.
*/
void sqlite3VdbeFreeCursor(Vdbe *p, Cursor *pCx){
  if( pCx==0 ){
    return;
  }
  if( pCx->pCursor ){
    sqlite3BtreeCloseCursor(pCx->pCursor);
................................................................................
    (void)sqlite3SafetyOff(p->db);
    pModule->xClose(pVtabCursor);
    (void)sqlite3SafetyOn(p->db);
    p->inVtabMethod = 0;
  }
#endif
  sqlite3_free(pCx->pData);

  sqlite3_free(pCx->aType);
  sqlite3_free(pCx);
}

/*
** Close all cursors except for VTab cursors that are currently
** in use.
*/
static void closeAllCursorsExceptActiveVtabs(Vdbe *p){
................................................................................
*/
static void Cleanup(Vdbe *p){
  int i;
  closeAllCursorsExceptActiveVtabs(p);
  for(i=1; i<=p->nMem; i++){
    MemSetTypeFlag(&p->aMem[i], MEM_Null);
  }

  releaseMemArray(&p->aMem[1], p->nMem);
  sqlite3VdbeFifoClear(&p->sFifo);
  if( p->contextStack ){
    for(i=0; i<p->contextStackTop; i++){
      sqlite3VdbeFifoClear(&p->contextStack[i].sFifo);
    }
    sqlite3_free(p->contextStack);

  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. This
   * is because the call to resizeOpArray() below may shrink the
   * p->aOp[] array to save memory if called when in VDBE_MAGIC_RUN 
   * state.
   */
  p->magic = VDBE_MAGIC_RUN;

  /* For each cursor required, also allocate a memory cell. Memory
  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
  ** the vdbe program. Instead they are used to allocate space for
  ** Cursor/BtCursor structures. The blob of memory associated with 
  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
  ** stores the blob of memory associated with cursor 1, etc.
  **
  ** See also: allocateCursor().
  */
  nMem += nCursor;

  /*
  ** Allocation space for registers.
  */
  if( p->aMem==0 ){
    int nArg;       /* Maximum number of args passed to a user function. */
    resolveP2Values(p, &nArg);
    resizeOpArray(p, p->nOp);
................................................................................
      p->aOp[i].cycles = 0;
    }
  }
#endif
}

/*
** Close a VDBE cursor and release all the resources that cursor 
** happens to hold.
*/
void sqlite3VdbeFreeCursor(Vdbe *p, Cursor *pCx){
  if( pCx==0 ){
    return;
  }
  if( pCx->pCursor ){
    sqlite3BtreeCloseCursor(pCx->pCursor);
................................................................................
    (void)sqlite3SafetyOff(p->db);
    pModule->xClose(pVtabCursor);
    (void)sqlite3SafetyOn(p->db);
    p->inVtabMethod = 0;
  }
#endif
  sqlite3_free(pCx->pData);
  memset(pCx, 0, sizeof(Cursor));
  /* sqlite3_free(pCx->aType); */
  /* sqlite3_free(pCx); */
}

/*
** Close all cursors except for VTab cursors that are currently
** in use.
*/
static void closeAllCursorsExceptActiveVtabs(Vdbe *p){
................................................................................
*/
static void Cleanup(Vdbe *p){
  int i;
  closeAllCursorsExceptActiveVtabs(p);
  for(i=1; i<=p->nMem; i++){
    MemSetTypeFlag(&p->aMem[i], MEM_Null);
  }

  releaseMemArray(&p->aMem[1], p->nMem);
  sqlite3VdbeFifoClear(&p->sFifo);
  if( p->contextStack ){
    for(i=0; i<p->contextStackTop; i++){
      sqlite3VdbeFifoClear(&p->contextStack[i].sFifo);
    }
    sqlite3_free(p->contextStack);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement incremental BLOB I/O.
**
** $Id: vdbeblob.c,v 1.20 2008/01/25 15:04:50 drh Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

................................................................................
  static const VdbeOpList openBlob[] = {
    {OP_Transaction, 0, 0, 0},     /* 0: Start a transaction */
    {OP_VerifyCookie, 0, 0, 0},    /* 1: Check the schema cookie */

    /* One of the following two instructions is replaced by an
    ** OP_Noop before exection.
    */
    {OP_OpenRead, 0, 0, 0},        /* 2: Open cursor 0 for reading */
    {OP_OpenWrite, 0, 0, 0},       /* 3: Open cursor 0 for read/write */
    {OP_SetNumColumns, 0, 0, 0},   /* 4: Num cols for cursor */


    {OP_Variable, 1, 1, 0},        /* 5: Push the rowid to the stack */
    {OP_NotExists, 0, 10, 1},      /* 6: Seek the cursor */
    {OP_Column, 0, 0, 1},          /* 7  */
    {OP_ResultRow, 1, 0, 0},       /* 8  */
    {OP_Close, 0, 0, 0},           /* 9  */
    {OP_Halt, 0, 0, 0},            /* 10 */
  };

  Vdbe *v = 0;
  int rc = SQLITE_OK;
  char zErr[128];

  zErr[0] = 0;
................................................................................

      /* Make sure a mutex is held on the table to be accessed */
      sqlite3VdbeUsesBtree(v, iDb); 

      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
      ** parameter of the other to pTab->tnum. 
      */
      sqlite3VdbeChangeToNoop(v, (flags ? 2 : 3), 1);
      sqlite3VdbeChangeP2(v, (flags ? 3 : 2), pTab->tnum);
      sqlite3VdbeChangeP3(v, (flags ? 3 : 2), iDb);

      /* Configure the OP_SetNumColumns. Configure the cursor to
      ** think that the table has one more column than it really
      ** does. An OP_Column to retrieve this imaginary column will
      ** always return an SQL NULL. This is useful because it means
      ** we can invoke OP_Column to fill in the vdbe cursors type 
      ** and offset cache without causing any IO.
      */
      sqlite3VdbeChangeP2(v, 4, pTab->nCol+1);
      if( !db->mallocFailed ){
        sqlite3VdbeMakeReady(v, 1, 1, 1, 0);
      }
    }
   
    sqlite3BtreeLeaveAll(db);
    rc = sqlite3SafetyOff(db);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement incremental BLOB I/O.
**
** $Id: vdbeblob.c,v 1.21 2008/03/25 09:47:35 danielk1977 Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

................................................................................
  static const VdbeOpList openBlob[] = {
    {OP_Transaction, 0, 0, 0},     /* 0: Start a transaction */
    {OP_VerifyCookie, 0, 0, 0},    /* 1: Check the schema cookie */

    /* One of the following two instructions is replaced by an
    ** OP_Noop before exection.
    */
    {OP_SetNumColumns, 0, 0, 0},   /* 2: Num cols for cursor */
    {OP_OpenRead, 0, 0, 0},        /* 3: Open cursor 0 for reading */
    {OP_SetNumColumns, 0, 0, 0},   /* 4: Num cols for cursor */
    {OP_OpenWrite, 0, 0, 0},       /* 5: Open cursor 0 for read/write */

    {OP_Variable, 1, 1, 0},        /* 6: Push the rowid to the stack */
    {OP_NotExists, 0, 10, 1},      /* 7: Seek the cursor */
    {OP_Column, 0, 0, 1},          /* 8  */
    {OP_ResultRow, 1, 0, 0},       /* 9  */
    {OP_Close, 0, 0, 0},           /* 10  */
    {OP_Halt, 0, 0, 0},            /* 11 */
  };

  Vdbe *v = 0;
  int rc = SQLITE_OK;
  char zErr[128];

  zErr[0] = 0;
................................................................................

      /* Make sure a mutex is held on the table to be accessed */
      sqlite3VdbeUsesBtree(v, iDb); 

      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
      ** parameter of the other to pTab->tnum. 
      */
      sqlite3VdbeChangeToNoop(v, (flags ? 3 : 5), 1);
      sqlite3VdbeChangeP2(v, (flags ? 5 : 3), pTab->tnum);
      sqlite3VdbeChangeP3(v, (flags ? 5 : 3), iDb);

      /* Configure the OP_SetNumColumns. Configure the cursor to
      ** think that the table has one more column than it really
      ** does. An OP_Column to retrieve this imaginary column will
      ** always return an SQL NULL. This is useful because it means
      ** we can invoke OP_Column to fill in the vdbe cursors type 
      ** and offset cache without causing any IO.
      */
      sqlite3VdbeChangeP2(v, flags ? 4 : 2, pTab->nCol+1);
      if( !db->mallocFailed ){
        sqlite3VdbeMakeReady(v, 1, 1, 1, 0);
      }
    }
   
    sqlite3BtreeLeaveAll(db);
    rc = sqlite3SafetyOff(db);

** 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 1.290 2008/03/17 17:08:33 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
#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;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP2(v, sqlite3VdbeCurrentAddr(v)-1, n);
        assert( n<=pTab->nCol );
      }
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    pLevel->iTabCur = pTabItem->iCursor;
    if( (pIx = pLevel->pIdx)!=0 ){
      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
      assert( pIx->pSchema==pTab->pSchema );

      sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb,
                        (char*)pKey, P4_KEYINFO_HANDOFF);
      VdbeComment((v, "%s", pIx->zName));
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, iIdxCur, pIx->nColumn+1);
    }
    sqlite3CodeVerifySchema(pParse, iDb);
  }
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM

** 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 1.291 2008/03/25 09:47:35 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
#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;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP2(v, sqlite3VdbeCurrentAddr(v)-2, n);
        assert( n<=pTab->nCol );
      }
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    pLevel->iTabCur = pTabItem->iCursor;
    if( (pIx = pLevel->pIdx)!=0 ){
      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
      assert( pIx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIx->nColumn+1);
      sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb,
                        (char*)pKey, P4_KEYINFO_HANDOFF);
      VdbeComment((v, "%s", pIx->zName));

    }
    sqlite3CodeVerifySchema(pParse, iDb);
  }
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM