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Diffstat (limited to 'includes/job/JobQueueAggregatorMemc.php')
-rw-r--r-- | includes/job/JobQueueAggregatorMemc.php | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/includes/job/JobQueueAggregatorMemc.php b/includes/job/JobQueueAggregatorMemc.php new file mode 100644 index 00000000..4b82cf92 --- /dev/null +++ b/includes/job/JobQueueAggregatorMemc.php @@ -0,0 +1,117 @@ +<?php +/** + * Job queue aggregator code that uses BagOStuff. + * + * 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 + * @author Aaron Schulz + */ + +/** + * Class to handle tracking information about all queues using BagOStuff + * + * @ingroup JobQueue + * @since 1.21 + */ +class JobQueueAggregatorMemc extends JobQueueAggregator { + /** @var BagOStuff */ + protected $cache; + + protected $cacheTTL; // integer; seconds + + /** + * @params include: + * - objectCache : Name of an object cache registered in $wgObjectCaches. + * This defaults to the one specified by $wgMainCacheType. + * - cacheTTL : Seconds to cache the aggregate data before regenerating. + * @param array $params + */ + protected function __construct( array $params ) { + parent::__construct( $params ); + $this->cache = isset( $params['objectCache'] ) + ? wfGetCache( $params['objectCache'] ) + : wfGetMainCache(); + $this->cacheTTL = isset( $params['cacheTTL'] ) ? $params['cacheTTL'] : 180; // 3 min + } + + /** + * @see JobQueueAggregator::doNotifyQueueEmpty() + */ + protected function doNotifyQueueEmpty( $wiki, $type ) { + $key = $this->getReadyQueueCacheKey(); + // Delist the queue from the "ready queue" list + if ( $this->cache->add( "$key:lock", 1, 60 ) ) { // lock + $curInfo = $this->cache->get( $key ); + if ( is_array( $curInfo ) && isset( $curInfo['pendingDBs'][$type] ) ) { + if ( in_array( $wiki, $curInfo['pendingDBs'][$type] ) ) { + $curInfo['pendingDBs'][$type] = array_diff( + $curInfo['pendingDBs'][$type], array( $wiki ) ); + $this->cache->set( $key, $curInfo ); + } + } + $this->cache->delete( "$key:lock" ); // unlock + } + return true; + } + + /** + * @see JobQueueAggregator::doNotifyQueueNonEmpty() + */ + protected function doNotifyQueueNonEmpty( $wiki, $type ) { + return true; // updated periodically + } + + /** + * @see JobQueueAggregator::doAllGetReadyWikiQueues() + */ + protected function doGetAllReadyWikiQueues() { + $key = $this->getReadyQueueCacheKey(); + // If the cache entry wasn't present, is stale, or in .1% of cases otherwise, + // regenerate the cache. Use any available stale cache if another process is + // currently regenerating the pending DB information. + $pendingDbInfo = $this->cache->get( $key ); + if ( !is_array( $pendingDbInfo ) + || ( time() - $pendingDbInfo['timestamp'] ) > $this->cacheTTL + || mt_rand( 0, 999 ) == 0 + ) { + if ( $this->cache->add( "$key:rebuild", 1, 1800 ) ) { // lock + $pendingDbInfo = array( + 'pendingDBs' => $this->findPendingWikiQueues(), + 'timestamp' => time() + ); + for ( $attempts=1; $attempts <= 25; ++$attempts ) { + if ( $this->cache->add( "$key:lock", 1, 60 ) ) { // lock + $this->cache->set( $key, $pendingDbInfo ); + $this->cache->delete( "$key:lock" ); // unlock + break; + } + } + $this->cache->delete( "$key:rebuild" ); // unlock + } + } + return is_array( $pendingDbInfo ) + ? $pendingDbInfo['pendingDBs'] + : array(); // cache is both empty and locked + } + + /** + * @return string + */ + private function getReadyQueueCacheKey() { + return "jobqueue:aggregator:ready-queues:v1"; // global + } +} |