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 1.195 2005/03/20 19:10:12 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  **
  ** If in EXCLUSIVE state, then we update the pager cache if it exists
  ** and the main file. The page is then marked not dirty.
  */
  pPg = pager_lookup(pPager, pgno);
  assert( pPager->state>=PAGER_EXCLUSIVE || pPg );
  TRACE3("PLAYBACK %d page %d\n", PAGERID(pPager), pgno);
  assert( jfd == (useCksum ? &pPager->jfd : &pPager->stfd) );
  if( pPager->state>=PAGER_EXCLUSIVE && (useCksum || !pPg || !pPg->needSync) ){
    sqlite3OsSeek(&pPager->fd, (pgno-1)*(i64)pPager->pageSize);
    rc = sqlite3OsWrite(&pPager->fd, aData, pPager->pageSize);
  }
  if( pPg ){
    /* No page should ever be explicitly 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. However such a page may be rolled back as a result

#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for the conflict resolution extension
# to SQLite.
#
# $Id: conflict.test,v 1.23 2005/03/20 19:10:13 drh Exp $

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

# Create tables for the first group of tests.
#
do_test conflict-1.0 {

    INSERT OR ROLLBACK INTO t4 VALUES(1);
    INSERT OR ROLLBACK INTO t4 VALUES(1);
    COMMIT;
  }
  execsql {SELECT * FROM t4}
} {}

# Ticket #1171.  Make sure statement rollbacks do not
# damage the database.
#
do_test conflict-11.1 {
  execsql {
    -- Create a database object (pages 2, 3 of the file)
    BEGIN;
      CREATE TABLE abc(a UNIQUE, b, c);
      INSERT INTO abc VALUES(1, 2, 3);
      INSERT INTO abc VALUES(4, 5, 6);
      INSERT INTO abc VALUES(7, 8, 9);
    COMMIT;
  }

  
  # Set a small cache size so that changes will spill into
  # the database file.  
  execsql {
    PRAGMA cache_size = 10;
  }
  
  # Make lots of changes.  Because of the small cache, some
  # (most?) of these changes will spill into the disk file.
  # In other words, some of the changes will not be held in
  # cache.
  #
  execsql {
    BEGIN;
      -- Make sure the pager is in EXCLUSIVE state.
      CREATE TABLE def(d, e, f);
      INSERT INTO def VALUES
          ('xxxxxxxxxxxxxxx', 'yyyyyyyyyyyyyyyy', 'zzzzzzzzzzzzzzzz');
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      DELETE FROM abc WHERE a = 4;
  }

  # Execute a statement that does a statement rollback due to
  # a constraint failure.
  #
  catchsql {
    INSERT INTO abc SELECT 10, 20, 30 FROM def;
  }

  # Rollback the database.  Verify that the state of the ABC table
  # is unchanged from the beginning of the transaction.  In other words,
  # make sure the DELETE on table ABC that occurred within the transaction
  # had no effect.
  #
  execsql {
    ROLLBACK;
    SELECT * FROM abc;
  }
} {1 2 3 4 5 6 7 8 9}
integrity_check conflict-11.2

# Repeat test conflict-11.1 but this time commit.
#
do_test conflict-11.3 {
  execsql {
    BEGIN;
      -- Make sure the pager is in EXCLUSIVE state.
      UPDATE abc SET a=a+1;
      CREATE TABLE def(d, e, f);
      INSERT INTO def VALUES
          ('xxxxxxxxxxxxxxx', 'yyyyyyyyyyyyyyyy', 'zzzzzzzzzzzzzzzz');
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      DELETE FROM abc WHERE a = 4;
  }
  catchsql {
    INSERT INTO abc SELECT 10, 20, 30 FROM def;
  }
  execsql {
    ROLLBACK;
    SELECT * FROM abc;
  }
} {1 2 3 4 5 6 7 8 9}
# Repeat test conflict-11.1 but this time commit.
#
do_test conflict-11.5 {
  execsql {
    BEGIN;
      -- Make sure the pager is in EXCLUSIVE state.
      CREATE TABLE def(d, e, f);
      INSERT INTO def VALUES
          ('xxxxxxxxxxxxxxx', 'yyyyyyyyyyyyyyyy', 'zzzzzzzzzzzzzzzz');
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      INSERT INTO def SELECT * FROM def;
      DELETE FROM abc WHERE a = 4;
  }
  catchsql {
    INSERT INTO abc SELECT 10, 20, 30 FROM def;
  }
  execsql {
    COMMIT;
    SELECT * FROM abc;
  }
} {1 2 3 7 8 9}
integrity_check conflict-11.6


finish_test