SQLite

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.486 2008/08/04 20:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif

  return rc;
}

/*
** Set up the lookaside buffers for a database connection.
** Return SQLITE_OK on success.  
** If lookaside is already active, return SQLITE_BUSY.
**
** The sz parameter is the number of bytes in each lookaside slot.
** The cnt parameter is the number of slots.  If pStart is NULL the
** space for the lookaside memory is obtained from sqlite3_malloc().
** If pStart is not NULL then it is sz*cnt bytes of memory to use for
** the lookaside memory.
*/
static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
  void *pStart;
  if( db->lookaside.nOut ){
    return SQLITE_BUSY;
  }
  if( sz<0 ) sz = 0;
  if( cnt<0 ) cnt = 0;
  sz = (sz+7)&~7;
  if( pBuf==0 ){
    sqlite3BeginBenignMalloc();
    pStart = sqlite3Malloc( sz*cnt );
    sqlite3EndBenignMalloc();
  }else{
    pStart = pBuf;
  }
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  db->lookaside.pStart = pStart;
  db->lookaside.pFree = 0;
  db->lookaside.sz = sz;
  db->lookaside.bMalloced = pBuf==0;
  if( pStart ){
    int i;
    LookasideSlot *p;
    p = (LookasideSlot*)pStart;
    for(i=cnt-1; i>=0; i--){
      p->pNext = db->lookaside.pFree;
      db->lookaside.pFree = p;

** Configuration settings for an individual database connection
*/
int sqlite3_db_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc;
  va_start(ap, op);
  switch( op ){
    case SQLITE_DBCONFIG_LOOKASIDE: {
      void *pBuf = va_arg(ap, void*);
      int sz = va_arg(ap, int);
      int cnt = va_arg(ap, int);
      rc = setupLookaside(db, pBuf, sz, cnt);
      break;
    }
    default: {
      rc = SQLITE_ERROR;
      break;
    }
  }

  ** the same sqliteMalloc() as the one that allocates the database 
  ** structure?
  */
  sqlite3DbFree(db, db->aDb[1].pSchema);
  sqlite3_mutex_leave(db->mutex);
  db->magic = SQLITE_MAGIC_CLOSED;
  sqlite3_mutex_free(db->mutex);
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  sqlite3_free(db);
  return SQLITE_OK;
}

/*
** Rollback all database files.
*/

#ifdef SQLITE_DEFAULT_LOCKING_MODE
  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
                          SQLITE_DEFAULT_LOCKING_MODE);
#endif

  /* Enable the lookaside-malloc subsystem */
  setupLookaside(db, 0, sqlite3Config.szLookaside, sqlite3Config.nLookaside);

opendb_out:
  if( db ){
    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3Config.bFullMutex==0 );
    sqlite3_mutex_leave(db->mutex);
  }
  if( SQLITE_NOMEM==(rc = sqlite3_errcode(db)) ){

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.386 2008/08/04 20:13:27 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

** sqlite3_db_config() interface can only be used immediately after
** the database connection is created using [sqlite3_open()],
** [sqlite3_open16()], or [sqlite3_open_v2()].  
**
** The second argument to sqlite3_db_config(D,V,...)  is the
** configuration verb - an integer code that indicates what
** aspect of the [database connection] is being configured.
** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
** New verbs are likely to be added in future releases of SQLite.
** Additional arguments depend on the verb.
*/
int sqlite3_db_config(sqlite3*, int op, ...);

/*
** CAPI3REF: Memory Allocation Routines {H10155} <S20120>
** EXPERIMENTAL
**

#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_CHUNKALLOC   12  /* int threshold */
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */

/*
** CAPI3REF: Configuration Options {H10170} <S20000>
** EXPERIMENTAL
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
** should check the return code from [sqlite3_db_config()] to make sure that
** the call worked.  The [sqlite3_db_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
** <dd>This option takes three additional arguments that determine the 
** [lookaside memory allocator] configuration for the [database connection].
** The first argument (the third parameter to [sqlite3_db_config()] is a
** pointer to a memory buffer to use for lookaside memory.  The first
** argument may be NULL in which case SQLite will allocate the lookaside
** buffer itself using [sqlite3_malloc()].  The second argument is the
** size of each lookaside buffer slot and the third argument is the number of
** slots.  The size of the buffer in the first argument must be greater than
** or equal to the product of the second and third arguments.</dd>
**
** </dl>
*/
#define SQLITE_DBCONFIG_LOOKASIDE    1001  /* void* int int */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700>
**
** The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. The extended result
** codes are disabled by default for historical compatibility considerations.

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.752 2008/08/04 20:13:27 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

** lookaside malloc subsystem.  Each available memory allocation in
** the lookaside subsystem is stored on a linked list of LookasideSlot
** objects.
*/
struct Lookaside {
  u16 sz;                 /* Size of each buffer in bytes */
  u8 bEnabled;            /* True if use lookaside.  False to ignore it */
  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
  int nOut;               /* Number of buffers currently checked out */
  int mxOut;              /* Highwater mark for nOut */
  LookasideSlot *pFree;   /* List if available buffers */
  void *pStart;           /* First byte of available memory space */
  void *pEnd;             /* First byte past end of available space */
};
struct LookasideSlot {

**    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 1.46 2008/08/04 20:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

  rc = sqlite3_config(SQLITE_CONFIG_LOOKASIDE, sz, cnt);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
  return TCL_OK;
}


/*
** Usage:    sqlite3_db_config_lookaside  CONNECTION  BUFID  SIZE  COUNT
**
** There are two static buffers with BUFID 1 and 2.   Each static buffer
** is 10KB in size.  A BUFID of 0 indicates that the buffer should be NULL
** which will cause sqlite3_db_config() to allocate space on its own.
*/
static int test_db_config_lookaside(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int rc;
  int sz, cnt;
  sqlite3 *db;
  int bufid;
  static char azBuf[2][10000];
  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
  if( objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "BUFID SIZE COUNT");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &bufid) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[3], &sz) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[4], &cnt) ) return TCL_ERROR;
  if( bufid==0 ){
    rc = sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE, 0, sz, cnt);
  }else if( bufid>=1 && bufid<=2 && sz*cnt<=sizeof(azBuf[0]) ){
    rc = sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE, azBuf[bufid], sz,cnt);
  }else{
    Tcl_AppendResult(interp, "illegal arguments - see documentation", (char*)0);
    return TCL_ERROR;
  }
  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
  return TCL_OK;
}

/*
** Usage:
**

#    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 ALTER TABLE statement and
# specifically out-of-memory conditions within that command.
#
# $Id: altermalloc.test,v 1.9 2008/08/04 20:13:27 drh Exp $
#

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

# If SQLITE_OMIT_ALTERTABLE is defined, omit this file.
ifcapable !altertable||!memdebug {
  finish_test
  return
}

source $testdir/malloc_common.tcl

do_malloc_test altermalloc-1 -tclprep {
  db close
} -tclbody {
  if {[catch {sqlite3 db test.db}]} {
    error "out of memory"
  }
  sqlite3_db_config_lookaside db 0 0 0
  sqlite3_extended_result_codes db 1
} -sqlbody {
  CREATE TABLE t1(a int);
  ALTER TABLE t1 ADD COLUMN b INTEGER DEFAULT NULL;
  ALTER TABLE t1 ADD COLUMN c TEXT DEFAULT 'default-text';
  ALTER TABLE t1 RENAME TO t2;
}

# Test malloc() failure on an ALTER TABLE on a virtual table.
#
ifcapable vtab {
  do_malloc_test altermalloc-vtab -tclprep {
    sqlite3 db2 test.db 
    sqlite3_db_config_lookaside db2 0 0 0
    sqlite3_extended_result_codes db2 1
    register_echo_module [sqlite3_connection_pointer db2]
    db2 eval {
      CREATE TABLE t1(a, b VARCHAR, c INTEGER);
      CREATE VIRTUAL TABLE t1echo USING echo(t1);
    }
    db2 close

#    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 statement and
# specifically out-of-memory conditions within that command.
#
# $Id: attachmalloc.test,v 1.9 2008/08/04 20:13:27 drh Exp $
#

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

ifcapable !memdebug||!attach {
  finish_test

    file delete -force test$i.db
    file delete -force test$i.db-journal
  }
} -tclbody {
  if {[catch {sqlite3 db test.db}]} {
    error "out of memory"
  }
  sqlite3_db_config_lookaside db 0 0 0
  sqlite3_extended_result_codes db 1
} -sqlbody {
  ATTACH 'test2.db' AS two;
  CREATE TABLE two.t1(x);
  ATTACH 'test3.db' AS three;
  CREATE TABLE three.t1(x);
  ATTACH 'test4.db' AS four;
  CREATE TABLE four.t1(x);
}

finish_test

# 2008 August 01
#
# 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.
#
#***********************************************************************
#
# Tests for the lookaside memory allocator.
#
# $Id: lookaside.test,v 1.3 2008/08/04 20:13:27 drh Exp $

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

catch {db close}
sqlite3_shutdown
sqlite3_config_pagecache 0 0
sqlite3_config_scratch 0 0
sqlite3_initialize
sqlite3 db test.db

# Make sure sqlite3_db_config() and sqlite3_db_status are working.
#
do_test lookaside-1.1 {
  catch {sqlite3_config_error db}
} {0}
do_test lookaside-1.2 {
  sqlite3_db_config_lookaside db 1 20 20
} {0}
do_test lookaside-1.3 {
  sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0
} {0 0 0}
do_test lookaside-1.4 {
  db eval {CREATE TABLE t1(x);}
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break

} {1}
do_test lookaside-1.9 {
  db cache flush
  sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0
} {0 0 0}

do_test lookaside-2.1 {
  sqlite3_db_config_lookaside db 0 100 1000
} {0}
do_test lookaside-2.2 {
  db eval {CREATE TABLE t2(x);}
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break
  expr {$x==0 && $y<$z && $z>10 && $z<100}
} {1}
do_test lookaside-2.3 {
  sqlite3_db_config_lookaside db 0 50 50
} {5}  ;# SQLITE_BUSY
do_test lookaside-2.4 {
  db cache flush
  sqlite3_db_config_lookaside db 0 50 50
} {0}  ;# SQLITE_OK

# sqlite3_db_status() with an invalid verb returns an error.
#
do_test lookaside-3.1 {
  sqlite3_db_status db 99999 0
} {1 0 0}

#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains common code used by many different malloc tests
# within the test suite.
#
# $Id: malloc_common.tcl,v 1.21 2008/08/04 20:13:27 drh Exp $

# If we did not compile with malloc testing enabled, then do nothing.
#
ifcapable builtin_test {
  set MEMDEBUG 1
} else {
  set MEMDEBUG 0

        if {[info exists ::mallocopts(-testdb)]} {
          file copy $::mallocopts(-testdb) test.db
        }
        catch { sqlite3 db test.db }
        if {[info commands db] ne ""} {
          sqlite3_extended_result_codes db 1
        }
        sqlite3_db_config_lookaside db 0 0 0
  
        # Execute any -tclprep and -sqlprep scripts.
        #
        if {[info exists ::mallocopts(-tclprep)]} {
          eval $::mallocopts(-tclprep)
        }
        if {[info exists ::mallocopts(-sqlprep)]} {

# 2008 June 18
#
# 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 tests of the memory allocation subsystem
#
# $Id: memsubsys1.test,v 1.8 2008/08/04 20:13:27 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
sqlite3_reset_auto_extension

# This procedure constructs a new database in test.db.  It fills
# this database with many small records (enough to force multiple
# rebalance operations in the btree-layer and to require a large
# page cache), verifies correct results, then returns.
#
proc build_test_db {testname pragmas} {
  catch {db close}
  file delete -force test.db test.db-journal
  sqlite3 db test.db
  sqlite3_db_config_lookaside db 0 0 0
  db eval $pragmas
  db eval {
    CREATE TABLE t1(x, y);
    CREATE TABLE t2(a, b);
    CREATE INDEX i1 ON t1(x,y);
    INSERT INTO t1 VALUES(1, 100);
    INSERT INTO t1 VALUES(2, 200);