** 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 1.300 2006/01/18 15:25:17 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................
#else

/*
** Save the current cursor position in the variables BtCursor.nKey 
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
*/
static int saveCursorPosition(BtCursor *pCur){
  int rc = SQLITE_OK;

  assert( CURSOR_VALID==pCur->eState|| CURSOR_INVALID==pCur->eState );
  assert( 0==pCur->pKey );

  if( pCur->eState==CURSOR_VALID ){
    rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);

    /* If this is an intKey table, then the above call to BtreeKeySize()
    ** stores the integer key in pCur->nKey. In this case this value is
    ** all that is required. Otherwise, if pCur is not open on an intKey
    ** table, then malloc space for and store the pCur->nKey bytes of key 
    ** data.
    */
    if( rc==SQLITE_OK && 0==pCur->pPage->intKey){
      void *pKey = sqliteMalloc(pCur->nKey);
      if( pKey ){
        rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
        if( rc==SQLITE_OK ){
          pCur->pKey = pKey;
        }else{
          sqliteFree(pKey);
        }
      }else{
        rc = SQLITE_NOMEM;
      }
    }
    assert( !pCur->pPage->intKey || !pCur->pKey );

    /* Todo: Should we drop the reference to pCur->pPage here? */

    if( rc==SQLITE_OK ){
      pCur->eState = CURSOR_REQUIRESEEK;
    }
  }

  return rc;
}

/*
** Save the positions of all cursors except pExcept open on the table 
................................................................................
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
static int restoreOrClearCursorPositionX(BtCursor *pCur, int doSeek){
  int rc = SQLITE_OK;
  assert( sqlite3ThreadDataReadOnly()->useSharedData );
  assert( pCur->eState==CURSOR_REQUIRESEEK );

  if( doSeek ){
    rc = sqlite3BtreeMoveto(pCur, pCur->pKey, pCur->nKey, &pCur->skip);
  }else{
    pCur->eState = CURSOR_INVALID;
  }
  if( rc==SQLITE_OK ){
    sqliteFree(pCur->pKey);
    pCur->pKey = 0;
    assert( CURSOR_VALID==pCur->eState || CURSOR_INVALID==pCur->eState );
  }
  return rc;

** 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 1.301 2006/01/19 07:18:14 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................
#else

/*
** Save the current cursor position in the variables BtCursor.nKey 
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
*/
static int saveCursorPosition(BtCursor *pCur){
  int rc;

  assert( CURSOR_VALID==pCur->eState );
  assert( 0==pCur->pKey );


  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);

  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( rc==SQLITE_OK && 0==pCur->pPage->intKey){
    void *pKey = sqliteMalloc(pCur->nKey);
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqliteFree(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
    }
  }
  assert( !pCur->pPage->intKey || !pCur->pKey );

  /* Todo: Should we drop the reference to pCur->pPage here? */

  if( rc==SQLITE_OK ){
    pCur->eState = CURSOR_REQUIRESEEK;

  }

  return rc;
}

/*
** Save the positions of all cursors except pExcept open on the table 
................................................................................
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
static int restoreOrClearCursorPositionX(BtCursor *pCur, int doSeek){
  int rc = SQLITE_OK;
  assert( sqlite3ThreadDataReadOnly()->useSharedData );
  assert( pCur->eState==CURSOR_REQUIRESEEK );
  pCur->eState = CURSOR_INVALID;
  if( doSeek ){
    rc = sqlite3BtreeMoveto(pCur, pCur->pKey, pCur->nKey, &pCur->skip);


  }
  if( rc==SQLITE_OK ){
    sqliteFree(pCur->pKey);
    pCur->pKey = 0;
    assert( CURSOR_VALID==pCur->eState || CURSOR_INVALID==pCur->eState );
  }
  return rc;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.197 2006/01/18 18:22:43 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  ClientData clientData,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  extern int sqlite3OutstandingMallocs(Tcl_Interp *interp);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( objc==2 ){
    ThreadData const *pTd = sqlite3ThreadDataReadOnly();
    const char *zArg = Tcl_GetString(objv[1]);


    if( 0==strcmp(zArg, "-bytes") ){
      Tcl_SetObjResult(interp, Tcl_NewIntObj(pTd->nAlloc));
    }else if( 0==strcmp(zArg, "-maxbytes") ){
      Tcl_SetObjResult(interp, Tcl_NewWideIntObj(sqlite3_nMaxAlloc));
    }else if( 0==strcmp(zArg, "-clearmaxbytes") ){
      sqlite3_nMaxAlloc = pTd->nAlloc;




    }else{
      Tcl_AppendResult(interp, "bad option \"", zArg, 
        "\": must be -bytes, -maxbytes or -clearmaxbytes", 0
      );
      return TCL_ERROR;
    }

    return TCL_OK;
  }
#endif

  if( objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?-bytes?");
    return TCL_ERROR;
  }

  return sqlite3OutstandingMallocs(interp);



}
#endif

/*
** Usage: sqlite3_enable_shared_cache      BOOLEAN
**
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.198 2006/01/19 07:18:14 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  ClientData clientData,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  extern int sqlite3OutstandingMallocs(Tcl_Interp *interp);

#if defined(SQLITE_DEBUG) && defined(SQLITE_MEMDEBUG)
  if( objc==2 ){

    const char *zArg = Tcl_GetString(objv[1]);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
    ThreadData const *pTd = sqlite3ThreadDataReadOnly();
    if( 0==strcmp(zArg, "-bytes") ){
      Tcl_SetObjResult(interp, Tcl_NewIntObj(pTd->nAlloc));


    }else if( 0==strcmp(zArg, "-clearmaxbytes") ){
      sqlite3_nMaxAlloc = pTd->nAlloc;
    }else 
#endif
    if( 0==strcmp(zArg, "-maxbytes") ){
      Tcl_SetObjResult(interp, Tcl_NewWideIntObj(sqlite3_nMaxAlloc));
    }else{
      Tcl_AppendResult(interp, "bad option \"", zArg, 
        "\": must be -bytes, -maxbytes or -clearmaxbytes", 0
      );
      return TCL_ERROR;
    }

    return TCL_OK;
  }


  if( objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?-bytes?");
    return TCL_ERROR;
  }

  return sqlite3OutstandingMallocs(interp);
#else
  return TCL_OK;
#endif
}
#endif

/*
** Usage: sqlite3_enable_shared_cache      BOOLEAN
**
*/

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.178 2006/01/18 18:22:43 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*
................................................................................
**     * The __LINE__ macro ...
**     * The value of the sqlite3_malloc_id variable ...
**     * The output of backtrace() (if available) ...
**
** Todo: We could have a version of this function that outputs to stdout, 
** to debug memory leaks when Tcl is not available.
*/
#ifdef TCLSH
#include <tcl.h>
int sqlite3OutstandingMallocs(Tcl_Interp *interp){
  void *p;
  Tcl_Obj *pRes = Tcl_NewObj();
  Tcl_IncrRefCount(pRes);


  for(p=sqlite3_pFirst; p; p=((void **)p)[1]){
    Tcl_Obj *pEntry = Tcl_NewObj();
    Tcl_Obj *pStack = Tcl_NewObj();
    char *z;
    u32 iLine;
    int nBytes = sqlite3OsAllocationSize(p) - TESTALLOC_OVERHEAD;
................................................................................
#endif

/*
** This is the test layer's wrapper around sqlite3OsMalloc().
*/
static void * OSMALLOC(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  ThreadData const *pTsd = sqlite3ThreadDataReadOnly();
  sqlite3_nMaxAlloc = MAX(sqlite3_nMaxAlloc, pTsd->nAlloc);
#endif
  assert( !sqlite3_mallocDisallowed );
  if( !sqlite3TestMallocFail() ){
    u32 *p;
    p = (u32 *)sqlite3OsMalloc(n + TESTALLOC_OVERHEAD);
    assert(p);
    sqlite3_nMalloc++;
................................................................................
}

/*
** This is the test layer's wrapper around sqlite3OsRealloc().
*/
static void * OSREALLOC(void *pRealloc, int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  ThreadData *pTsd = sqlite3ThreadData();
  if( !pTsd ){
    return 0;
  }
  sqlite3_nMaxAlloc = MAX(sqlite3_nMaxAlloc, pTsd->nAlloc);
#endif
  assert( !sqlite3_mallocDisallowed );
  if( !sqlite3TestMallocFail() ){
    u32 *p = (u32 *)getOsPointer(pRealloc);
    checkGuards(p);
    p = sqlite3OsRealloc(p, n + TESTALLOC_OVERHEAD);
    applyGuards(p);

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.179 2006/01/19 07:18:14 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*
................................................................................
**     * The __LINE__ macro ...
**     * The value of the sqlite3_malloc_id variable ...
**     * The output of backtrace() (if available) ...
**
** Todo: We could have a version of this function that outputs to stdout, 
** to debug memory leaks when Tcl is not available.
*/
#if defined(TCLSH) && defined(SQLITE_DEBUG) && SQLITE_MEMDEBUG>1
#include <tcl.h>
int sqlite3OutstandingMallocs(Tcl_Interp *interp){
  void *p;
  Tcl_Obj *pRes = Tcl_NewObj();
  Tcl_IncrRefCount(pRes);


  for(p=sqlite3_pFirst; p; p=((void **)p)[1]){
    Tcl_Obj *pEntry = Tcl_NewObj();
    Tcl_Obj *pStack = Tcl_NewObj();
    char *z;
    u32 iLine;
    int nBytes = sqlite3OsAllocationSize(p) - TESTALLOC_OVERHEAD;
................................................................................
#endif

/*
** This is the test layer's wrapper around sqlite3OsMalloc().
*/
static void * OSMALLOC(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  sqlite3_nMaxAlloc = 
      MAX(sqlite3_nMaxAlloc, sqlite3ThreadDataReadOnly()->nAlloc);
#endif
  assert( !sqlite3_mallocDisallowed );
  if( !sqlite3TestMallocFail() ){
    u32 *p;
    p = (u32 *)sqlite3OsMalloc(n + TESTALLOC_OVERHEAD);
    assert(p);
    sqlite3_nMalloc++;
................................................................................
}

/*
** This is the test layer's wrapper around sqlite3OsRealloc().
*/
static void * OSREALLOC(void *pRealloc, int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  sqlite3_nMaxAlloc = 



      MAX(sqlite3_nMaxAlloc, sqlite3ThreadDataReadOnly()->nAlloc);
#endif
  assert( !sqlite3_mallocDisallowed );
  if( !sqlite3TestMallocFail() ){
    u32 *p = (u32 *)getOsPointer(pRealloc);
    checkGuards(p);
    p = sqlite3OsRealloc(p, n + TESTALLOC_OVERHEAD);
    applyGuards(p);

#
#    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: shared.test,v 1.17 2006/01/17 09:35:02 danielk1977 Exp $

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

ifcapable !shared_cache {
  finish_test
................................................................................
} else {
  if {$av} {
    db close
    break
  }
}






incr av

# Test organization:
#
# shared-1.*: Simple test to verify basic sanity of table level locking when
#             two connections share a pager cache.
# shared-2.*: Test that a read transaction can co-exist with a 
................................................................................

do_test shared-$av.3.1.1 {
  # This test case starts a linear scan of table 'seq' using a 
  # read-uncommitted connection. In the middle of the scan, rows are added
  # to the end of the seq table (ahead of the current cursor position).
  # The uncommitted rows should be included in the results of the scan.
  execsql "
    CREATE TABLE seq(i, x);
    INSERT INTO seq VALUES(1, '[string repeat X 500]');
    INSERT INTO seq VALUES(2, '[string repeat X 500]');
  "
  execsql {SELECT * FROM sqlite_master} db2
  execsql {PRAGMA read_uncommitted = 1} db2

  set ret [list]
  db2 eval {SELECT i FROM seq} {
    if {$i < 4} {
      set max [execsql {SELECT max(i) FROM seq}]
      db eval {
        INSERT INTO seq SELECT i + :max, x FROM seq;
      }
    }
    lappend ret $i

#
#    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: shared.test,v 1.18 2006/01/19 07:18:15 danielk1977 Exp $

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

ifcapable !shared_cache {
  finish_test
................................................................................
} else {
  if {$av} {
    db close
    break
  }
}

# $av is currently 0 if this loop iteration is to test with auto-vacuum turned
# off, and 1 if it is turned on. Increment it so that (1 -> no auto-vacuum) 
# and (2 -> auto-vacuum). The sole reason for this is so that it looks nicer
# when we use this variable as part of test-case names.
#
incr av

# Test organization:
#
# shared-1.*: Simple test to verify basic sanity of table level locking when
#             two connections share a pager cache.
# shared-2.*: Test that a read transaction can co-exist with a 
................................................................................

do_test shared-$av.3.1.1 {
  # This test case starts a linear scan of table 'seq' using a 
  # read-uncommitted connection. In the middle of the scan, rows are added
  # to the end of the seq table (ahead of the current cursor position).
  # The uncommitted rows should be included in the results of the scan.
  execsql "
    CREATE TABLE seq(i PRIMARY KEY, x);
    INSERT INTO seq VALUES(1, '[string repeat X 500]');
    INSERT INTO seq VALUES(2, '[string repeat X 500]');
  "
  execsql {SELECT * FROM sqlite_master} db2
  execsql {PRAGMA read_uncommitted = 1} db2

  set ret [list]
  db2 eval {SELECT i FROM seq ORDER BY i} {
    if {$i < 4} {
      set max [execsql {SELECT max(i) FROM seq}]
      db eval {
        INSERT INTO seq SELECT i + :max, x FROM seq;
      }
    }
    lappend ret $i