wiki.techinc.nl/includes/DataUpdate.php
Alexandre Emsenhuber 3bbda787b8 Added missing GPLv2 headers in some places.
Also made file/class documentation more consistent.

Change-Id: Ic1ba00472ef62fa4fd746f8f590fe694d490ecd9
2012-05-20 17:56:43 +02:00

120 lines
3.2 KiB
PHP

<?php
/**
* Base code for update jobs that do something with some secondary
* data extracted from article.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
/**
* Abstract base class for update jobs that do something with some secondary
* data extracted from article.
*/
abstract class DataUpdate implements DeferrableUpdate {
/**
* Constructor
*/
public function __construct( ) {
# noop
}
/**
* Begin an appropriate transaction, if any.
* This default implementation does nothing.
*/
public function beginTransaction() {
//noop
}
/**
* Commit the transaction started via beginTransaction, if any.
* This default implementation does nothing.
*/
public function commitTransaction() {
//noop
}
/**
* Abort / roll back the transaction started via beginTransaction, if any.
* This default implementation does nothing.
*/
public function rollbackTransaction() {
//noop
}
/**
* Convenience method, calls doUpdate() on every DataUpdate in the array.
*
* This methods supports transactions logic by first calling beginTransaction()
* on all updates in the array, then calling doUpdate() on each, and, if all goes well,
* then calling commitTransaction() on each update. If an error occurrs,
* rollbackTransaction() will be called on any update object that had beginTranscation()
* called but not yet commitTransaction().
*
* This allows for limited transactional logic across multiple backends for storing
* secondary data.
*
* @static
* @param $updates array a list of DataUpdate instances
*/
public static function runUpdates( $updates ) {
if ( empty( $updates ) ) return; # nothing to do
$open_transactions = array();
$exception = null;
/**
* @var $update StorageUpdate
* @var $trans StorageUpdate
*/
try {
// begin transactions
foreach ( $updates as $update ) {
$update->beginTransaction();
$open_transactions[] = $update;
}
// do work
foreach ( $updates as $update ) {
$update->doUpdate();
}
// commit transactions
while ( count( $open_transactions ) > 0 ) {
$trans = array_pop( $open_transactions );
$trans->commitTransaction();
}
} catch ( Exception $ex ) {
$exception = $ex;
wfDebug( "Caught exception, will rethrow after rollback: " . $ex->getMessage() );
}
// rollback remaining transactions
while ( count( $open_transactions ) > 0 ) {
$trans = array_pop( $open_transactions );
$trans->rollbackTransaction();
}
if ( $exception ) {
throw $exception; // rethrow after cleanup
}
}
}