SQLite

/*
** 2005 July 8
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.23 2007/08/29 17:43:20 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

*/
int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
  analysisInfo sInfo;
  HashElem *i;
  char *zSql;
  int rc;

  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pBt!=0 );
  assert( sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );

  /* Clear any prior statistics */
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3DefaultRowEst(pIdx);
  }

/*
** 2007 August 27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** $Id: btmutex.c,v 1.6 2007/08/29 17:43:20 drh Exp $
**
** This file contains code used to implement mutexes on Btree objects.
** This code really belongs in btree.c.  But btree.c is getting too
** big and we want to break it down some.  This packaged seemed like
** a good breakout.
*/
#include "btreeInt.h"

      p->locked = 0;
    }
  }
}

#ifndef NDEBUG
/*
** Return true if the BtShared mutex is held on the btree.  
**
** This routine makes no determination one why or another if the
** database connection mutex is held.
**
** This routine is used only from within assert() statements.
*/
int sqlite3BtreeHoldsMutex(Btree *p){

  return (p->sharable==0 ||
             (p->locked && p->wantToLock && sqlite3_mutex_held(p->pBt->mutex)));
}
#endif


#ifndef SQLITE_OMIT_INCRBLOB
/*
** Enter and leave a mutex on a Btree given a cursor owned by that
** Btree.  These entry points are used by incremental I/O and can be
** omitted if that module is not used.
*/
void sqlite3BtreeEnterCursor(BtCursor *pCur){
  sqlite3BtreeEnter(pCur->pBtree);
}
void sqlite3BtreeLeaveCursor(BtCursor *pCur){
  sqlite3BtreeLeave(pCur->pBtree);
}
#endif /* SQLITE_OMIT_INCRBLOB */


/*
** Enter the mutex on every Btree associated with a database
** connection.  This is needed (for example) prior to parsing
** a statement since we will be comparing table and column names
** against all schemas and we do not want those schemas being
** reset out from under us.

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.418 2007/08/29 17:43:20 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"

static void releasePage(MemPage *pPage);  /* Forward reference */

/*
** Verify that the cursor holds a mutex on the BtShared
*/
#ifndef NDEBUG
static int cursorHoldsMutex(BtCursor *p){
  return sqlite3_mutex_held(p->pBt->mutex);
}
#endif


#ifndef SQLITE_OMIT_INCRBLOB
/*
** Invalidate the overflow page-list cache for cursor pCur, if any.

  ** If this Btree is a candidate for shared cache, try to find an
  ** existing BtShared object that we can share with
  */
  if( (flags & BTREE_PRIVATE)==0
   && isMemdb==0
   && (pSqlite->flags & SQLITE_Vtab)==0
   && zFilename && zFilename[0]

  ){
    if( sqlite3SharedCacheEnabled ){
      char *zFullPathname = (char *)sqlite3_malloc(pVfs->mxPathname);
      sqlite3_mutex *mutexShared;
      p->sharable = 1;
      if( pSqlite ){
        pSqlite->flags |= SQLITE_SharedCache;
      }
      if( !zFullPathname ){
        sqlite3_free(p);
        return SQLITE_NOMEM;
      }
      sqlite3OsFullPathname(pVfs, zFilename, zFullPathname);
      mutexShared = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
      sqlite3_mutex_enter(mutexShared);
      for(pBt=sqlite3SharedCacheList; pBt; pBt=pBt->pNext){
        assert( pBt->nRef>0 );
        if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager))
                 && sqlite3PagerVfs(pBt->pPager)==pVfs ){
          p->pBt = pBt;
          pBt->nRef++;
          break;
        }
      }
      sqlite3_mutex_leave(mutexShared);
      sqlite3_free(zFullPathname);
    }
#ifdef SQLITE_DEBUG
    else{
      /* In debug mode, we mark all persistent databases as sharable
      ** even when they are not.  This exercises the locking code and
      ** gives more opportunity for asserts(sqlite3_mutex_held())
      ** statements to find locking problems.
      */
      p->sharable = 1;
    }
#endif
  }
#endif
  if( pBt==0 ){
    /*
    ** The following asserts make sure that structures used by the btree are
    ** the right size.  This is to guard against size changes that result
    ** when compiling on a different architecture.

    /* Add the new BtShared object to the linked list sharable BtShareds.
    */
    if( p->sharable ){
      sqlite3_mutex *mutexShared;
      pBt->nRef = 1;
      mutexShared = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
      pBt->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
      if( pBt->mutex==0 ){
        rc = SQLITE_NOMEM;
        pSqlite->mallocFailed = 0;
        goto btree_open_out;
      }
      sqlite3_mutex_enter(mutexShared);
      pBt->pNext = sqlite3SharedCacheList;
      sqlite3SharedCacheList = pBt;
      sqlite3_mutex_leave(mutexShared);
    }
#endif
  }

/*
** 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);
  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.
*/

** Return the full pathname of the underlying database file.
**
** The pager filename is invariant as long as the pager is
** open so it is safe to access without the BtShared mutex.
*/
const char *sqlite3BtreeGetFilename(Btree *p){
  assert( p->pBt->pPager!=0 );

  return sqlite3PagerFilename(p->pBt->pPager);
}

/*
** Return the pathname of the directory that contains the database file.
**
** The pager directory name is invariant as long as the pager is
** open so it is safe to access without the BtShared mutex.
*/
const char *sqlite3BtreeGetDirname(Btree *p){
  assert( p->pBt->pPager!=0 );

  return sqlite3PagerDirname(p->pBt->pPager);
}

/*
** Return the pathname of the journal file for this database. The return
** value of this routine is the same regardless of whether the journal file
** has been created or not.
**
** The pager journal filename is invariant as long as the pager is
** open so it is safe to access without the BtShared mutex.
*/
const char *sqlite3BtreeGetJournalname(Btree *p){
  assert( p->pBt->pPager!=0 );

  return sqlite3PagerJournalname(p->pBt->pPager);
}

#ifndef SQLITE_OMIT_VACUUM
/*
** Copy the complete content of pBtFrom into pBtTo.  A transaction
** must be active for both files.

**    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 1.91 2007/08/29 17:43:20 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
  void sqlite3BtreeEnter(Btree*);
  void sqlite3BtreeLeave(Btree*);
  int sqlite3BtreeHoldsMutex(Btree*);
  void sqlite3BtreeEnterCursor(BtCursor*);
  void sqlite3BtreeLeaveCursor(BtCursor*);
  void sqlite3BtreeEnterAll(sqlite3*);
  void sqlite3BtreeLeaveAll(sqlite3*);
  int sqlite3BtreeHoldsAllMutexes(sqlite3*);
  void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
#else
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeHoldsMutex(X) 1
# define sqlite3BtreeEnterCursor(X)
# define sqlite3BtreeLeaveCursor(X)
# define sqlite3BtreeEnterAll(X)
# define sqlite3BtreeLeaveAll(X)
# define sqlite3BtreeHoldsAllMutexes(X) 1
# define sqlite3BtreeMutexArrayEnter(X)
# define sqlite3BtreeMutexArrayLeave(X)
# define sqlite3BtreeMutexArrayInsert(X,Y)
#endif


#endif /* _BTREE_H_ */

**    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 1.84 2007/08/29 17:43:20 drh Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeBeginTrans(pBt, 1);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeRollback(pBt);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCommit(pBt);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeBeginStmt(pBt);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeRollbackStmt(pBt);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  int rc;
  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCommitStmt(pBt);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID FLAGS\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &flags) ) return TCL_ERROR;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeCreateTable(pBt, &iTable, flags);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf), zBuf, "%d", iTable);
  Tcl_AppendResult(interp, zBuf, 0);
  return TCL_OK;

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeDropTable(pBt, iTable, &notUsed1);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreeClearTable(pBt, iTable);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  for(i=0; i<SQLITE_N_BTREE_META; i++){
    char zBuf[30];
    unsigned int v;
    sqlite3BtreeEnter(pBt);
    rc = sqlite3BtreeGetMeta(pBt, i, &v);
    sqlite3BtreeLeave(pBt);
    if( rc!=SQLITE_OK ){
      Tcl_AppendResult(interp, errorName(rc), 0);
      return TCL_ERROR;
    }
    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",v);
    Tcl_AppendElement(interp, zBuf);
  }

    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  for(i=1; i<SQLITE_N_BTREE_META; i++){
    if( Tcl_GetInt(interp, argv[i+2], &aMeta[i]) ) return TCL_ERROR;
  }
  for(i=1; i<SQLITE_N_BTREE_META; i++){
    sqlite3BtreeEnter(pBt);
    rc = sqlite3BtreeUpdateMeta(pBt, i, aMeta[i]);
    sqlite3BtreeLeave(pBt);
    if( rc!=SQLITE_OK ){
      Tcl_AppendResult(interp, errorName(rc), 0);
      return TCL_ERROR;
    }
  }
  return TCL_OK;
}

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iPage) ) return TCL_ERROR;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreePageDump(pBt, iPage, 0);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iPage) ) return TCL_ERROR;
  sqlite3BtreeEnter(pBt);
  rc = sqlite3BtreePageDump(pBt, iPage, 1);
  sqlite3BtreeLeave(pBt);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);

  sqlite3BtreeEnter(pBt);
  a = sqlite3PagerStats(sqlite3BtreePager(pBt));
  for(i=0; i<11; i++){
    static char *zName[] = {
      "ref", "page", "max", "size", "state", "err",
      "hit", "miss", "ovfl", "read", "write"
    };
    char zBuf[100];
    Tcl_AppendElement(interp, zName[i]);
    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",a[i]);
    Tcl_AppendElement(interp, zBuf);
  }
  sqlite3BtreeLeave(pBt);

  return TCL_OK;
}

/*
** Usage:   btree_pager_ref_dump ID
**
** Print out all outstanding pages.

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
#ifdef SQLITE_DEBUG
  sqlite3BtreeEnter(pBt);
  sqlite3PagerRefdump(sqlite3BtreePager(pBt));
  sqlite3BtreeLeave(pBt);
#endif
  return TCL_OK;
}

/*
** Usage:   btree_integrity_check ID ROOT ...
**

  pBt = sqlite3TextToPtr(argv[1]);
  nRoot = argc-2;
  aRoot = (int*)sqlite3_malloc( sizeof(int)*(argc-2) );
  for(i=0; i<argc-2; i++){
    if( Tcl_GetInt(interp, argv[i+2], &aRoot[i]) ) return TCL_ERROR;
  }
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  sqlite3BtreeEnter(pBt);
  zResult = sqlite3BtreeIntegrityCheck(pBt, aRoot, nRoot, 10000, &nErr);
  sqlite3BtreeLeave(pBt);
#else
  zResult = 0;
#endif
  sqlite3_free((void*)aRoot);
  if( zResult ){
    Tcl_AppendResult(interp, zResult, 0);
    sqlite3_free(zResult); 

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pBt);
  sqlite3BtreeCursorList(pBt);
  sqlite3BtreeLeave(pBt);
  return SQLITE_OK;
}

/*
** Usage:   btree_cursor ID TABLENUM WRITEABLE
**
** Create a new cursor.  Return the ID for the cursor.

    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, 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;

static int btree_close_cursor(
  void *NotUsed,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  const char **argv      /* Text of each argument */
){
  BtCursor *pCur;
  Btree *pBt;
  int rc;

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    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;
}

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID KEY\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
    int iKey;
    if( Tcl_GetInt(interp, argv[2], &iKey) ){
      sqlite3BtreeLeave(pCur->pBtree);
      return TCL_ERROR;
    }
    rc = sqlite3BtreeMoveto(pCur, 0, iKey, 0, &res);
  }else{
    rc = sqlite3BtreeMoveto(pCur, argv[2], strlen(argv[2]), 0, &res);  
  }
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  if( res<0 ) res = -1;
  if( res>0 ) res = 1;
  sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",res);

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeDelete(pCur);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return SQLITE_OK;
}

  }
  pCur = sqlite3TextToPtr(Tcl_GetString(objv[1]));
  if( objc==5 ){
    if( Tcl_GetIntFromObj(interp, objv[4], &nZero) ) return TCL_ERROR;
  }else{
    nZero = 0;
  }
  sqlite3BtreeEnter(pCur->pBtree);
  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
    i64 iKey;
    int len;
    unsigned char *pBuf;
    if( Tcl_GetWideIntFromObj(interp, objv[2], &iKey) ){
      sqlite3BtreeLeave(pCur->pBtree);
      return TCL_ERROR;
    }
    pBuf = Tcl_GetByteArrayFromObj(objv[3], &len);
    rc = sqlite3BtreeInsert(pCur, 0, iKey, pBuf, len, nZero, 0);
  }else{
    int keylen;
    int dlen;
    unsigned char *pKBuf;
    unsigned char *pDBuf;
    pKBuf = Tcl_GetByteArrayFromObj(objv[2], &keylen);
    pDBuf = Tcl_GetByteArrayFromObj(objv[3], &dlen);
    rc = sqlite3BtreeInsert(pCur, pKBuf, keylen, pDBuf, dlen, nZero, 0);
  }
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return SQLITE_OK;
}

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeNext(pCur, &res);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreePrevious(pCur, &res);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeFirst(pCur, &res);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeLast(pCur, &res);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;

static int btree_eof(
  void *NotUsed,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  const char **argv      /* Text of each argument */
){
  BtCursor *pCur;
  int rc;
  char zBuf[50];

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeEof(pCur);
  sqlite3BtreeLeave(pCur->pBtree);
  sqlite3_snprintf(sizeof(zBuf),zBuf, "%d", rc);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;
}

/*
** Usage:   btree_keysize ID
**

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  sqlite3BtreeKeySize(pCur, (i64*)&n);
  sqlite3BtreeLeave(pCur->pBtree);
  sqlite3_snprintf(sizeof(zBuf),zBuf, "%llu", n);
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;
}

/*
** Usage:   btree_key ID

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  sqlite3BtreeKeySize(pCur, (i64*)&n);
  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
    char zBuf2[60];
    sqlite3_snprintf(sizeof(zBuf2),zBuf2, "%llu", n);
    Tcl_AppendResult(interp, zBuf2, 0);
  }else{
    zBuf = sqlite3_malloc( n+1 );
    rc = sqlite3BtreeKey(pCur, 0, n, zBuf);
    if( rc ){
      sqlite3BtreeLeave(pCur->pBtree);
      Tcl_AppendResult(interp, errorName(rc), 0);
      return TCL_ERROR;
    }
    zBuf[n] = 0;
    Tcl_AppendResult(interp, zBuf, 0);
    sqlite3_free(zBuf);
  }
  sqlite3BtreeLeave(pCur->pBtree);
  return SQLITE_OK;
}

/*
** Usage:   btree_data ID ?N?
**
** Return the data for the entry at which the cursor is pointing.

  if( argc!=2 && argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  if( argc==2 ){
    sqlite3BtreeDataSize(pCur, &n);
  }else{
    n = atoi(argv[2]);
  }
  zBuf = sqlite3_malloc( n+1 );
  rc = sqlite3BtreeData(pCur, 0, n, zBuf);
  sqlite3BtreeLeave(pCur->pBtree);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    sqlite3_free(zBuf);
    return TCL_ERROR;
  }
  zBuf[n] = 0;
  Tcl_AppendResult(interp, zBuf, 0);

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID AMT\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
  sqlite3BtreeEnter(pCur->pBtree);
  sqlite3BtreeKeySize(pCur, (i64*)&nKey);
  zBuf = sqlite3BtreeKeyFetch(pCur, &amt);
  if( zBuf && amt>=n ){
    assert( nKey<sizeof(zStatic) );
    if( n>0 ) nKey = n;
    memcpy(zStatic, zBuf, (int)nKey); 
    zStatic[nKey] = 0;
    Tcl_AppendResult(interp, zStatic, 0);
  }
  sqlite3BtreeLeave(pCur->pBtree);
  return TCL_OK;
}

/*
** Usage:   btree_fetch_data ID AMT
**
** Use the sqlite3BtreeDataFetch() routine to get AMT bytes of the key.

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID AMT\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
  sqlite3BtreeEnter(pCur->pBtree);
  sqlite3BtreeDataSize(pCur, &nData);
  zBuf = sqlite3BtreeDataFetch(pCur, &amt);
  if( zBuf && amt>=n ){
    assert( nData<sizeof(zStatic) );
    if( n>0 ) nData = n;
    memcpy(zStatic, zBuf, (int)nData); 
    zStatic[nData] = 0;
    Tcl_AppendResult(interp, zStatic, 0);
  }
  sqlite3BtreeLeave(pCur->pBtree);
  return TCL_OK;
}

/*
** Usage:   btree_payload_size ID
**
** Return the number of bytes of payload

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pCur = sqlite3TextToPtr(argv[1]);
  sqlite3BtreeEnter(pCur->pBtree);
  if( sqlite3BtreeFlags(pCur) & BTREE_INTKEY ){
    n1 = 0;
  }else{
    sqlite3BtreeKeySize(pCur, (i64*)&n1);
  }
  sqlite3BtreeDataSize(pCur, (u32*)&n2);
  sqlite3BtreeLeave(pCur->pBtree);
  sqlite3_snprintf(sizeof(zBuf),zBuf, "%d", (int)(n1+n2));
  Tcl_AppendResult(interp, zBuf, 0);
  return SQLITE_OK;
}

/*
** Usage:   btree_cursor_info ID ?UP-CNT?

  }
  pCur = sqlite3TextToPtr(argv[1]);
  if( argc==3 ){
    if( Tcl_GetInt(interp, argv[2], &up) ) return TCL_ERROR;
  }else{
    up = 0;
  }
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeCursorInfo(pCur, aResult, up);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    sqlite3BtreeLeave(pCur->pBtree);
    return TCL_ERROR;
  }
  j = 0;
  for(i=0; i<sizeof(aResult)/sizeof(aResult[0]); i++){
    sqlite3_snprintf(40,&zBuf[j]," %d", aResult[i]);
    j += strlen(&zBuf[j]);
  }
  sqlite3BtreeLeave(pCur->pBtree);
  Tcl_AppendResult(interp, &zBuf[1], 0);
  return SQLITE_OK;
}

/*
** Copied from btree.c:
*/

  pBt = sqlite3TextToPtr(argv[1]);
  pCur = sqlite3TextToPtr(argv[2]);
  if( (*(void**)pCur) != (void*)pBt ){
    Tcl_AppendResult(interp, "Cursor ", argv[2], " does not belong to btree ",
       argv[1], 0);
    return TCL_ERROR;
  }
  sqlite3BtreeEnter(pBt);
  pPager = sqlite3BtreePager(pBt);
  rc = sqlite3BtreeCursorInfo(pCur, aResult, 0);
  if( rc ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    sqlite3BtreeLeave(pBt);
    return TCL_ERROR;
  }
  dataSize = sqlite3BtreeGetPageSize(pBt) - sqlite3BtreeGetReserve(pBt);
  Tcl_DStringInit(&str);
  n = aResult[6] - aResult[8];
  n = (n + dataSize - 1)/dataSize;
  pgno = (u32)aResult[10];
  while( pgno && n-- ){
    DbPage *pDbPage;
    sprintf(zElem, "%d", pgno);
    Tcl_DStringAppendElement(&str, zElem);
    if( sqlite3PagerGet(pPager, pgno, &pDbPage)!=SQLITE_OK ){
      Tcl_DStringFree(&str);
      Tcl_AppendResult(interp, "unable to get page ", zElem, 0);
      sqlite3BtreeLeave(pBt);
      return TCL_ERROR;
    }
    pPage = sqlite3PagerGetData(pDbPage);
    pgno = t4Get4byte((unsigned char*)pPage);
    sqlite3PagerUnref(pDbPage);
  }
  sqlite3BtreeLeave(pBt);
  Tcl_DStringResult(interp, &str);
  return SQLITE_OK;
}

/*
** The command is provided for the purpose of setting breakpoints.
** in regression test scripts.

       " BT NCACHE\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &nCache) ) return TCL_ERROR;

  sqlite3_mutex_enter(pBt->pSqlite->mutex);
  sqlite3BtreeEnter(pBt);
  sqlite3BtreeSetCacheSize(pBt, nCache);
  sqlite3BtreeLeave(pBt);
  sqlite3_mutex_leave(pBt->pSqlite->mutex);

  return TCL_OK;
}


/*

      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 ){

#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){
  int i;
  if( p->apCsr==0 ) return;
  for(i=0; i<p->nCursor; i++){
    Cursor *pC = p->apCsr[i];
    if( pC && (!p->inVtabMethod || !pC->pVtabCursor) ){
      sqlite3VdbeFreeCursor(p, pC);
      p->apCsr[i] = 0;
    }
  }
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, lists, and/or
** sorters that were left open.  It also deletes the values of
** variables in the aVar[] array.
*/
static void Cleanup(Vdbe *p){
  int i;
  if( p->aStack ){
    releaseMemArray(p->aStack, 1 + (p->pTos - p->aStack));
    p->pTos = &p->aStack[-1];
  }
  closeAllCursorsExceptActiveVtabs(p);
  releaseMemArray(p->aMem, p->nMem);
  sqlite3VdbeFifoClear(&p->sFifo);
  if( p->contextStack ){
    for(i=0; i<p->contextStackTop; i++){
      sqlite3VdbeFifoClear(&p->contextStack[i].sFifo);
    }
    sqlite3_free(p->contextStack);

*/
void sqlite3AbortOtherActiveVdbes(sqlite3 *db, Vdbe *pExcept){
  Vdbe *pOther;
  for(pOther=db->pVdbe; pOther; pOther=pOther->pNext){
    if( pOther==pExcept ) continue;
    if( pOther->magic!=VDBE_MAGIC_RUN || pOther->pc<0 ) continue;
    checkActiveVdbeCnt(db);
    closeAllCursorsExceptActiveVtabs(pOther);
    checkActiveVdbeCnt(db);
    pOther->aborted = 1;
  }
}

/*
** This routine is called the when a VDBE tries to halt.  If the VDBE
** has made changes and is in autocommit mode, then commit those
** changes.  If a rollback is needed, then do the rollback.
**
** This routine is the only way to move the state of a VM from
** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT.  It is harmless to
** call this on a VM that is in the SQLITE_MAGIC_HALT state.
**
** Return an error code.  If the commit could not complete because of
** lock contention, return SQLITE_BUSY.  If SQLITE_BUSY is returned, it
** means the close did not happen and needs to be repeated.
*/
int sqlite3VdbeHalt(Vdbe *p){
  sqlite3 *db = p->db;
  int i;
  int (*xFunc)(Btree *pBt) = 0;  /* Function to call on each btree backend */
  int isSpecialError;            /* Set to true if SQLITE_NOMEM or IOERR */

  /* This function contains the logic that determines if a statement or
  ** transaction will be committed or rolled back as a result of the

  ** No error:
  **
  */

  if( p->db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
  }
  closeAllCursorsExceptActiveVtabs(p);
  if( p->magic!=VDBE_MAGIC_RUN ){





    return SQLITE_OK;
  }

  checkActiveVdbeCnt(db);

  /* No commit or rollback needed if the program never started */
  if( p->pc>=0 ){
    int mrc;   /* Primary error code from p->rc */

    /* Lock all btrees used by the statement */
    sqlite3BtreeMutexArrayEnter(&p->aMutex);

    /* Check for one of the special errors - SQLITE_NOMEM or SQLITE_IOERR */
    mrc = p->rc & 0xff;
    isSpecialError = (
        (mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR || mrc==SQLITE_INTERRUPT)?1:0);
    if( isSpecialError ){
      /* This loop does static analysis of the query to see which of the
      ** following three categories it falls into:

            }
            break;
          case OP_Statement:
            isStatement = 1;
            break;
        }
      }

   
      /* If the query was read-only, we need do no rollback at all. Otherwise,
      ** proceed with the special handling.
      */
      if( !isReadOnly ){
        if( p->rc==SQLITE_IOERR_BLOCKED && isStatement ){
          xFunc = sqlite3BtreeRollbackStmt;
          p->rc = SQLITE_BUSY;

      if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
        /* The auto-commit flag is true, and the vdbe program was 
        ** successful or hit an 'OR FAIL' constraint. This means a commit 
        ** is required.
        */
        int rc = vdbeCommit(db);
        if( rc==SQLITE_BUSY ){
          sqlite3BtreeMutexArrayLeave(&p->aMutex);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db);
        }else{
          sqlite3CommitInternalChanges(db);
        }

    }
  
    /* Rollback or commit any schema changes that occurred. */
    if( p->rc!=SQLITE_OK && db->flags&SQLITE_InternChanges ){
      sqlite3ResetInternalSchema(db, 0);
      db->flags = (db->flags | SQLITE_InternChanges);
    }

    /* Release the locks */
    sqlite3BtreeMutexArrayLeave(&p->aMutex);
  }

  /* We have successfully halted and closed the VM.  Record this fact. */
  if( p->pc>=0 ){
    db->activeVdbeCnt--;
  }
  p->magic = VDBE_MAGIC_HALT;
  checkActiveVdbeCnt(db);
  if( p->db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
  }
  checkActiveVdbeCnt(db);

  return SQLITE_OK;
}









/*
** Each VDBE holds the result of the most recent sqlite3_step() call
** in p->rc.  This routine sets that result back to SQLITE_OK.
*/
void sqlite3VdbeResetStepResult(Vdbe *p){

**    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 1.15 2007/08/29 17:43:20 drh Exp $
*/

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

#ifndef SQLITE_OMIT_INCRBLOB

    rc = sqlite3SafetyOn(db);
    if( rc!=SQLITE_OK ){
      sqlite3_mutex_leave(db->mutex);
      return rc;
    }

    sqlite3BtreeEnterAll(db);
    pTab = sqlite3LocateTable(&sParse, zTable, zDb);
    if( !pTab ){
      if( sParse.zErrMsg ){
        sqlite3_snprintf(sizeof(zErr), zErr, "%s", sParse.zErrMsg);
      }
      sqlite3_free(sParse.zErrMsg);
      rc = SQLITE_ERROR;
      sqlite3SafetyOff(db);
      sqlite3BtreeLeaveAll(db);
      goto blob_open_out;
    }

    /* Now search pTab for the exact column. */
    for(iCol=0; iCol < pTab->nCol; iCol++) {
      if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
        break;
      }
    }
    if( iCol==pTab->nCol ){
      sqlite3_snprintf(sizeof(zErr), zErr, "no such column: \"%s\"", zColumn);
      rc = SQLITE_ERROR;
      sqlite3SafetyOff(db);
      sqlite3BtreeLeaveAll(db);
      goto blob_open_out;
    }

    /* If the value is being opened for writing, check that the
    ** column is not indexed. It is against the rules to open an
    ** indexed column for writing.
    */
    if( flags ){
      Index *pIdx;
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nColumn; j++){
          if( pIdx->aiColumn[j]==iCol ){
            sqlite3_snprintf(sizeof(zErr), zErr,
                             "cannot open indexed column for writing");
            rc = SQLITE_ERROR;
            sqlite3SafetyOff(db);
            sqlite3BtreeLeaveAll(db);
            goto blob_open_out;
          }
        }
      }
    }

    v = sqlite3VdbeCreate(db);
    if( v ){
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);

      /* Configure the OP_Transaction */
      sqlite3VdbeChangeP1(v, 0, iDb);
      sqlite3VdbeChangeP2(v, 0, (flags ? 1 : 0));

      /* Configure the OP_VerifyCookie */
      sqlite3VdbeChangeP1(v, 1, iDb);
      sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);

      /* Make sure a mutex is held on the table to be accessed */
      sqlite3VdbeUsesBtree(v, iDb, db->aDb[iDb].pBt); 

      /* Configure the db number pushed onto the stack */
      sqlite3VdbeChangeP1(v, 2, iDb);

      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
      ** parameter of the other to pTab->tnum. 
      */

      ** and offset cache without causing any IO.
      */
      sqlite3VdbeChangeP2(v, 5, pTab->nCol+1);
      if( !db->mallocFailed ){
        sqlite3VdbeMakeReady(v, 1, 0, 1, 0);
      }
    }
   
    sqlite3BtreeLeaveAll(db);
    rc = sqlite3SafetyOff(db);
    if( rc!=SQLITE_OK || db->mallocFailed ){
      goto blob_open_out;
    }

    sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow);
    rc = sqlite3_step((sqlite3_stmt *)v);

    pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
    if( db->mallocFailed ){
      sqlite3_free(pBlob);
      goto blob_open_out;
    }
    pBlob->flags = flags;
    pBlob->pCsr =  v->apCsr[0]->pCursor;
    sqlite3BtreeEnterCursor(pBlob->pCsr);
    sqlite3BtreeCacheOverflow(pBlob->pCsr);
    sqlite3BtreeLeaveCursor(pBlob->pCsr);
    pBlob->pStmt = (sqlite3_stmt *)v;
    pBlob->iOffset = v->apCsr[0]->aOffset[iCol];
    pBlob->nByte = sqlite3VdbeSerialTypeLen(type);
    pBlob->db = db;
    *ppBlob = (sqlite3_blob *)pBlob;
    rc = SQLITE_OK;
  }else if( rc==SQLITE_OK ){

/*
** Close a blob handle that was previously created using
** sqlite3_blob_open().
*/
int sqlite3_blob_close(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;

  int rc;


  rc = sqlite3_finalize(p->pStmt);

  sqlite3_free(p);
  return rc;
}

/*
** Perform a read or write operation on a blob
*/

  if( v==0 ){
    rc = SQLITE_ABORT;
  }else{
    /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
    ** returned, clean-up the statement handle.
    */
    assert( db == v->db );
    sqlite3BtreeEnterCursor(p->pCsr);
    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
    sqlite3BtreeLeaveCursor(p->pCsr);
    if( rc==SQLITE_ABORT ){
      sqlite3VdbeFinalize(v);
      p->pStmt = 0;
    }else{
      db->errCode = rc;
      v->rc = rc;
    }

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach.test,v 1.45 2007/08/29 17:43:20 drh Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

for {set i 2} {$i<=15} {incr i} {
  file delete -force test$i.db

} {1 x 2 y}
do_test attach-1.4 {
  execsql {
    SELECT * FROM t2;
  }
} {1 x 2 y}
do_test attach-1.5 {
btree_breakpoint
  execsql {
    DETACH DATABASE two;
    SELECT * FROM t1;
  }
} {1 2 3 4}
do_test attach-1.6 {
  catchsql {