SQLite

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.91 2003/12/17 23:57:35 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  ** at the same time, if there is one.
  */
  pPg = pager_lookup(pPager, pgRec.pgno);
  TRACE2("PLAYBACK %d\n", pgRec.pgno);
  sqliteOsSeek(&pPager->fd, (pgRec.pgno-1)*(off_t)SQLITE_PAGE_SIZE);
  rc = sqliteOsWrite(&pPager->fd, pgRec.aData, SQLITE_PAGE_SIZE);
  if( pPg ){



    /* No page should ever be rolled back that is in use, except for page
    ** 1 which is held in use in order to keep the lock on the database
    ** active.




    */
    assert( pPg->nRef==0 || pPg->pgno==1 );
    memcpy(PGHDR_TO_DATA(pPg), pgRec.aData, SQLITE_PAGE_SIZE);
    memset(PGHDR_TO_EXTRA(pPg), 0, pPager->nExtra);

    pPg->dirty = 0;
    pPg->needSync = 0;
  }
  return rc;
}

/*

#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for miscellanous features that were
# left out of other test files.
#
# $Id: misc2.test,v 1.11 2003/12/17 23:57:36 drh Exp $

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

# Test for ticket #360
#
do_test misc2-1.1 {

    SELECT dim1.n, dim2.n, dim3.n, dim4.n
    FROM counts AS dim1, counts AS dim2, counts AS dim3, counts AS dim4
    WHERE dim1.n<5 AND dim2.n<5 AND dim3.n<5 AND dim4.n<5;

    SELECT count(*) FROM x;
  }
} [expr 5*5*5*5]

finish_test

# 2003 December 17
#
# 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 implements regression tests for SQLite library.
#
# This file implements tests for miscellanous features that were
# left out of other test files.
#
# $Id: misc3.test,v 1.1 2003/12/17 23:57:36 drh Exp $

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

# Ticket #529.  Make sure an ABORT does not damage the in-memory cache
# that will be used by subsequent statements in the same transaction.
#
do_test misc3-1.1 {
  execsql {
    CREATE TABLE t1(a UNIQUE,b);
    INSERT INTO t1
      VALUES(1,'a23456789_b23456789_c23456789_d23456789_e23456789_');
    UPDATE t1 SET b=b||b;
    UPDATE t1 SET b=b||b;
    UPDATE t1 SET b=b||b;
    UPDATE t1 SET b=b||b;
    UPDATE t1 SET b=b||b;
    INSERT INTO t1 VALUES(2,'x');
    UPDATE t1 SET b=substr(b,1,500);
    BEGIN;
  }
  catchsql {UPDATE t1 SET a=CASE a WHEN 2 THEN 1 ELSE a END, b='y';}
  execsql {
    CREATE TABLE t2(x,y);
    COMMIT;
    PRAGMA integrity_check;
  }
} ok
do_test misc3-1.2 {
  execsql {
    DROP TABLE t1;
    DROP TABLE t2;
    VACUUM;
    CREATE TABLE t1(a UNIQUE,b);
    INSERT INTO t1
       VALUES(1,'a23456789_b23456789_c23456789_d23456789_e23456789_');
    INSERT INTO t1 SELECT a+1, b||b FROM t1;
    INSERT INTO t1 SELECT a+2, b||b FROM t1;
    INSERT INTO t1 SELECT a+4, b FROM t1;
    INSERT INTO t1 SELECT a+8, b FROM t1;
    INSERT INTO t1 SELECT a+16, b FROM t1;
    INSERT INTO t1 SELECT a+32, b FROM t1;
    INSERT INTO t1 SELECT a+64, b FROM t1;

    BEGIN;
  }
  catchsql {UPDATE t1 SET a=CASE a WHEN 128 THEN 127 ELSE a END, b='';}
  execsql {
    INSERT INTO t1 VALUES(200,'hello out there');
    COMMIT;
    PRAGMA integrity_check;
  }
} ok

finish_test