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Direktori : /data/www_bck/varak.net_bck/havranipapuce.varak.net/includes/deferred/ |
Current File : //data/www_bck/varak.net_bck/havranipapuce.varak.net/includes/deferred/DataUpdate.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. * * @note subclasses should NOT start or commit transactions in their doUpdate() method, * a transaction will automatically be wrapped around the update. If need be, * subclasses can override the beginTransaction() and commitTransaction() methods. */ 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 occurs, * rollbackTransaction() will be called on any update object that had beginTransaction() * called but not yet commitTransaction(). * * This allows for limited transactional logic across multiple backends for storing * secondary data. * * @param array $updates A list of DataUpdate instances * @throws Exception|null */ public static function runUpdates( $updates ) { if ( empty( $updates ) ) { return; # nothing to do } $open_transactions = array(); $exception = null; /** * @var $update DataUpdate * @var $trans DataUpdate */ 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() . "\n" ); } // rollback remaining transactions while ( count( $open_transactions ) > 0 ) { $trans = array_pop( $open_transactions ); $trans->rollbackTransaction(); } if ( $exception ) { throw $exception; // rethrow after cleanup } } }