includes/job/JobQueueAggregator.php

   1 <?php
   2 /**
   3  * Job queue aggregator code.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Aaron Schulz
  22  */
  23
  24 /**
  25  * Class to handle tracking information about all queues
  26  *
  27  * @ingroup JobQueue
  28  * @since 1.21
  29  */
  30 abstract class JobQueueAggregator {
  31         /** @var JobQueueAggregator */
  32         protected static $instance = null;
  33
  34         /**
  35          * @param array $params
  36          */
  37         protected function __construct( array $params ) {}
  38
  39         /**
  40          * @return JobQueueAggregator
  41          */
  42         final public static function singleton() {
  43                 global $wgJobQueueAggregator;
  44
  45                 if ( !isset( self::$instance ) ) {
  46                         $class = $wgJobQueueAggregator['class'];
  47                         $obj = new $class( $wgJobQueueAggregator );
  48                         if ( !( $obj instanceof JobQueueAggregator ) ) {
  49                                 throw new MWException( "Class '$class' is not a JobQueueAggregator class." );
  50                         }
  51                         self::$instance = $obj;
  52                 }
  53
  54                 return self::$instance;
  55         }
  56
  57         /**
  58          * Destroy the singleton instance
  59          *
  60          * @return void
  61          */
  62         final public static function destroySingleton() {
  63                 self::$instance = null;
  64         }
  65
  66         /**
  67          * Mark a queue as being empty
  68          *
  69          * @param string $wiki
  70          * @param string $type
  71          * @return bool Success
  72          */
  73         final public function notifyQueueEmpty( $wiki, $type ) {
  74                 wfProfileIn( __METHOD__ );
  75                 $ok = $this->doNotifyQueueEmpty( $wiki, $type );
  76                 wfProfileOut( __METHOD__ );
  77                 return $ok;
  78         }
  79
  80         /**
  81          * @see JobQueueAggregator::notifyQueueEmpty()
  82          */
  83         abstract protected function doNotifyQueueEmpty( $wiki, $type );
  84
  85         /**
  86          * Mark a queue as being non-empty
  87          *
  88          * @param string $wiki
  89          * @param string $type
  90          * @return bool Success
  91          */
  92         final public function notifyQueueNonEmpty( $wiki, $type ) {
  93                 wfProfileIn( __METHOD__ );
  94                 $ok = $this->doNotifyQueueNonEmpty( $wiki, $type );
  95                 wfProfileOut( __METHOD__ );
  96                 return $ok;
  97         }
  98
  99         /**
 100          * @see JobQueueAggregator::notifyQueueNonEmpty()
 101          */
 102         abstract protected function doNotifyQueueNonEmpty( $wiki, $type );
 103
 104         /**
 105          * Get the list of all of the queues with jobs
 106          *
 107          * @return Array (job type => (list of wiki IDs))
 108          */
 109         final public function getAllReadyWikiQueues() {
 110                 wfProfileIn( __METHOD__ );
 111                 $res = $this->doGetAllReadyWikiQueues();
 112                 wfProfileOut( __METHOD__ );
 113                 return $res;
 114         }
 115
 116         /**
 117          * @see JobQueueAggregator::getAllReadyWikiQueues()
 118          */
 119         abstract protected function doGetAllReadyWikiQueues();
 120
 121         /**
 122          * Purge all of the aggregator information
 123          *
 124          * @return bool Success
 125          */
 126         final public function purge() {
 127                 wfProfileIn( __METHOD__ );
 128                 $res = $this->doPurge();
 129                 wfProfileOut( __METHOD__ );
 130                 return $res;
 131         }
 132
 133         /**
 134          * @see JobQueueAggregator::purge()
 135          */
 136         abstract protected function doPurge();
 137
 138         /**
 139          * Get all databases that have a pending job.
 140          * This poll all the queues and is this expensive.
 141          *
 142          * @return Array (job type => (list of wiki IDs))
 143          */
 144         protected function findPendingWikiQueues() {
 145                 global $wgLocalDatabases;
 146
 147                 $pendingDBs = array(); // (job type => (db list))
 148                 foreach ( $wgLocalDatabases as $db ) {
 149                         foreach ( JobQueueGroup::singleton( $db )->getQueuesWithJobs() as $type ) {
 150                                 $pendingDBs[$type][] = $db;
 151                         }
 152                 }
 153
 154                 return $pendingDBs;
 155         }
 156 }