wiki.techinc.nl/includes/DeferredUpdates.php
Alexandre Emsenhuber e1bc8fd885 Catch exceptions thrown while running deferred updates.
Such exceptions should not reported to the user because the main output
is already sent. Otherwise the user will recive a double reponse with
is just horribly looking. Instead just log these exceptions to keep a
trace of them. This also adds an higher isolation level for these
updates and the post-response cleanup.

Change-Id: I60c2c5ba8ab2ec2d835d8d3042584e98a62809be
2012-07-12 23:14:40 +02:00

119 lines
3.2 KiB
PHP

<?php
/**
* Interface and manager for deferred updates.
*
* 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
*/
/**
* Interface that deferrable updates should implement. Basically required so we
* can validate input on DeferredUpdates::addUpdate()
*
* @since 1.19
*/
interface DeferrableUpdate {
/**
* Perform the actual work
*/
function doUpdate();
}
/**
* Class for mananging the deferred updates.
*
* @since 1.19
*/
class DeferredUpdates {
/**
* Store of updates to be deferred until the end of the request.
*/
private static $updates = array();
/**
* Add an update to the deferred list
* @param $update DeferrableUpdate Some object that implements doUpdate()
*/
public static function addUpdate( DeferrableUpdate $update ) {
array_push( self::$updates, $update );
}
/**
* HTMLCacheUpdates are the most common deferred update people use. This
* is a shortcut method for that.
* @see HTMLCacheUpdate::__construct()
* @param $title
* @param $table
*/
public static function addHTMLCacheUpdate( $title, $table ) {
self::addUpdate( new HTMLCacheUpdate( $title, $table ) );
}
/**
* Do any deferred updates and clear the list
*
* @param $commit String: set to 'commit' to commit after every update to
* prevent lock contention
*/
public static function doUpdates( $commit = '' ) {
global $wgDeferredUpdateList;
wfProfileIn( __METHOD__ );
$updates = array_merge( $wgDeferredUpdateList, self::$updates );
// No need to get master connections in case of empty updates array
if ( !count( $updates ) ) {
wfProfileOut( __METHOD__ );
return;
}
$doCommit = $commit == 'commit';
if ( $doCommit ) {
$dbw = wfGetDB( DB_MASTER );
}
foreach ( $updates as $update ) {
try {
$update->doUpdate();
if ( $doCommit && $dbw->trxLevel() ) {
$dbw->commit( __METHOD__ );
}
} catch ( MWException $e ) {
// We don't want exceptions thrown during deferred updates to
// be reported to the user since the output is already sent.
// Instead we just log them.
if ( !$e instanceof ErrorPageError ) {
wfDebugLog( 'exception', $e->getLogMessage() );
}
}
}
self::clearPendingUpdates();
wfProfileOut( __METHOD__ );
}
/**
* Clear all pending updates without performing them. Generally, you don't
* want or need to call this. Unit tests need it though.
*/
public static function clearPendingUpdates() {
global $wgDeferredUpdateList;
$wgDeferredUpdateList = self::$updates = array();
}
}