includes/job/aggregator/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         /**
  41          * @return JobQueueAggregator
  42          */
  43         final public static function singleton() {
  44                 global $wgJobQueueAggregator;
  45
  46                 if ( !isset( self::$instance ) ) {
  47                         $class = $wgJobQueueAggregator['class'];
  48                         $obj = new $class( $wgJobQueueAggregator );
  49                         if ( !( $obj instanceof JobQueueAggregator ) ) {
  50                                 throw new MWException( "Class '$class' is not a JobQueueAggregator class." );
  51                         }
  52                         self::$instance = $obj;
  53                 }
  54
  55                 return self::$instance;
  56         }
  57
  58         /**
  59          * Destroy the singleton instance
  60          *
  61          * @return void
  62          */
  63         final public static function destroySingleton() {
  64                 self::$instance = null;
  65         }
  66
  67         /**
  68          * Mark a queue as being empty
  69          *
  70          * @param string $wiki
  71          * @param string $type
  72          * @return bool Success
  73          */
  74         final public function notifyQueueEmpty( $wiki, $type ) {
  75                 wfProfileIn( __METHOD__ );
  76                 $ok = $this->doNotifyQueueEmpty( $wiki, $type );
  77                 wfProfileOut( __METHOD__ );
  78
  79                 return $ok;
  80         }
  81
  82         /**
  83          * @see JobQueueAggregator::notifyQueueEmpty()
  84          */
  85         abstract protected function doNotifyQueueEmpty( $wiki, $type );
  86
  87         /**
  88          * Mark a queue as being non-empty
  89          *
  90          * @param string $wiki
  91          * @param string $type
  92          * @return bool Success
  93          */
  94         final public function notifyQueueNonEmpty( $wiki, $type ) {
  95                 wfProfileIn( __METHOD__ );
  96                 $ok = $this->doNotifyQueueNonEmpty( $wiki, $type );
  97                 wfProfileOut( __METHOD__ );
  98
  99                 return $ok;
 100         }
 101
 102         /**
 103          * @see JobQueueAggregator::notifyQueueNonEmpty()
 104          */
 105         abstract protected function doNotifyQueueNonEmpty( $wiki, $type );
 106
 107         /**
 108          * Get the list of all of the queues with jobs
 109          *
 110          * @return Array (job type => (list of wiki IDs))
 111          */
 112         final public function getAllReadyWikiQueues() {
 113                 wfProfileIn( __METHOD__ );
 114                 $res = $this->doGetAllReadyWikiQueues();
 115                 wfProfileOut( __METHOD__ );
 116
 117                 return $res;
 118         }
 119
 120         /**
 121          * @see JobQueueAggregator::getAllReadyWikiQueues()
 122          */
 123         abstract protected function doGetAllReadyWikiQueues();
 124
 125         /**
 126          * Purge all of the aggregator information
 127          *
 128          * @return bool Success
 129          */
 130         final public function purge() {
 131                 wfProfileIn( __METHOD__ );
 132                 $res = $this->doPurge();
 133                 wfProfileOut( __METHOD__ );
 134
 135                 return $res;
 136         }
 137
 138         /**
 139          * @see JobQueueAggregator::purge()
 140          */
 141         abstract protected function doPurge();
 142
 143         /**
 144          * Get all databases that have a pending job.
 145          * This poll all the queues and is this expensive.
 146          *
 147          * @return Array (job type => (list of wiki IDs))
 148          */
 149         protected function findPendingWikiQueues() {
 150                 global $wgLocalDatabases;
 151
 152                 $pendingDBs = array(); // (job type => (db list))
 153                 foreach ( $wgLocalDatabases as $db ) {
 154                         foreach ( JobQueueGroup::singleton( $db )->getQueuesWithJobs() as $type ) {
 155                                 $pendingDBs[$type][] = $db;
 156                         }
 157                 }
 158
 159                 return $pendingDBs;
 160         }
 161 }