includes/jobqueue/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         public function __construct( array $params ) {
  38         }
  39
  40         /**
  41          * @throws MWException
  42          * @return JobQueueAggregator
  43          */
  44         final public static function singleton() {
  45                 global $wgJobQueueAggregator;
  46
  47                 if ( !isset( self::$instance ) ) {
  48                         $class = $wgJobQueueAggregator['class'];
  49                         $obj = new $class( $wgJobQueueAggregator );
  50                         if ( !( $obj instanceof JobQueueAggregator ) ) {
  51                                 throw new MWException( "Class '$class' is not a JobQueueAggregator class." );
  52                         }
  53                         self::$instance = $obj;
  54                 }
  55
  56                 return self::$instance;
  57         }
  58
  59         /**
  60          * Destroy the singleton instance
  61          *
  62          * @return void
  63          */
  64         final public static function destroySingleton() {
  65                 self::$instance = null;
  66         }
  67
  68         /**
  69          * Mark a queue as being empty
  70          *
  71          * @param string $wiki
  72          * @param string $type
  73          * @return bool Success
  74          */
  75         final public function notifyQueueEmpty( $wiki, $type ) {
  76                 $ok = $this->doNotifyQueueEmpty( $wiki, $type );
  77
  78                 return $ok;
  79         }
  80
  81         /**
  82          * @see JobQueueAggregator::notifyQueueEmpty()
  83          */
  84         abstract protected function doNotifyQueueEmpty( $wiki, $type );
  85
  86         /**
  87          * Mark a queue as being non-empty
  88          *
  89          * @param string $wiki
  90          * @param string $type
  91          * @return bool Success
  92          */
  93         final public function notifyQueueNonEmpty( $wiki, $type ) {
  94                 $ok = $this->doNotifyQueueNonEmpty( $wiki, $type );
  95
  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                 $res = $this->doGetAllReadyWikiQueues();
 111
 112                 return $res;
 113         }
 114
 115         /**
 116          * @see JobQueueAggregator::getAllReadyWikiQueues()
 117          */
 118         abstract protected function doGetAllReadyWikiQueues();
 119
 120         /**
 121          * Purge all of the aggregator information
 122          *
 123          * @return bool Success
 124          */
 125         final public function purge() {
 126                 $res = $this->doPurge();
 127
 128                 return $res;
 129         }
 130
 131         /**
 132          * @see JobQueueAggregator::purge()
 133          */
 134         abstract protected function doPurge();
 135
 136         /**
 137          * Get all databases that have a pending job.
 138          * This poll all the queues and is this expensive.
 139          *
 140          * @return array (job type => (list of wiki IDs))
 141          */
 142         protected function findPendingWikiQueues() {
 143                 global $wgLocalDatabases;
 144
 145                 $pendingDBs = []; // (job type => (db list))
 146                 foreach ( $wgLocalDatabases as $db ) {
 147                         foreach ( JobQueueGroup::singleton( $db )->getQueuesWithJobs() as $type ) {
 148                                 $pendingDBs[$type][] = $db;
 149                         }
 150                 }
 151
 152                 return $pendingDBs;
 153         }
 154 }
 155
 156 class JobQueueAggregatorNull extends JobQueueAggregator {
 157         protected function doNotifyQueueEmpty( $wiki, $type ) {
 158                 return true;
 159         }
 160
 161         protected function doNotifyQueueNonEmpty( $wiki, $type ) {
 162                 return true;
 163         }
 164
 165         protected function doGetAllReadyWikiQueues() {
 166                 return [];
 167         }
 168
 169         protected function doPurge() {
 170                 return true;
 171         }
 172 }