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  */
  22
  23 /**
  24  * Class to handle tracking information about all queues
  25  *
  26  * @ingroup JobQueue
  27  * @since 1.21
  28  */
  29 abstract class JobQueueAggregator {
  30         /** @var JobQueueAggregator */
  31         protected static $instance = null;
  32
  33         /**
  34          * @param array $params
  35          */
  36         public function __construct( array $params ) {
  37         }
  38
  39         /**
  40          * @throws MWException
  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                 $ok = $this->doNotifyQueueEmpty( $wiki, $type );
  76
  77                 return $ok;
  78         }
  79
  80         /**
  81          * @see JobQueueAggregator::notifyQueueEmpty()
  82          * @param string $wiki
  83          * @param string $type
  84          * @return bool
  85          */
  86         abstract protected function doNotifyQueueEmpty( $wiki, $type );
  87
  88         /**
  89          * Mark a queue as being non-empty
  90          *
  91          * @param string $wiki
  92          * @param string $type
  93          * @return bool Success
  94          */
  95         final public function notifyQueueNonEmpty( $wiki, $type ) {
  96                 $ok = $this->doNotifyQueueNonEmpty( $wiki, $type );
  97
  98                 return $ok;
  99         }
 100
 101         /**
 102          * @see JobQueueAggregator::notifyQueueNonEmpty()
 103          * @param string $wiki
 104          * @param string $type
 105          * @return bool
 106          */
 107         abstract protected function doNotifyQueueNonEmpty( $wiki, $type );
 108
 109         /**
 110          * Get the list of all of the queues with jobs
 111          *
 112          * @return array (job type => (list of wiki IDs))
 113          */
 114         final public function getAllReadyWikiQueues() {
 115                 $res = $this->doGetAllReadyWikiQueues();
 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                 $res = $this->doPurge();
 132
 133                 return $res;
 134         }
 135
 136         /**
 137          * @see JobQueueAggregator::purge()
 138          */
 139         abstract protected function doPurge();
 140
 141         /**
 142          * Get all databases that have a pending job.
 143          * This poll all the queues and is this expensive.
 144          *
 145          * @return array (job type => (list of wiki IDs))
 146          */
 147         protected function findPendingWikiQueues() {
 148                 global $wgLocalDatabases;
 149
 150                 $pendingDBs = []; // (job type => (db list))
 151                 foreach ( $wgLocalDatabases as $db ) {
 152                         foreach ( JobQueueGroup::singleton( $db )->getQueuesWithJobs() as $type ) {
 153                                 $pendingDBs[$type][] = $db;
 154                         }
 155                 }
 156
 157                 return $pendingDBs;
 158         }
 159 }
 160
 161 class JobQueueAggregatorNull extends JobQueueAggregator {
 162         protected function doNotifyQueueEmpty( $wiki, $type ) {
 163                 return true;
 164         }
 165
 166         protected function doNotifyQueueNonEmpty( $wiki, $type ) {
 167                 return true;
 168         }
 169
 170         protected function doGetAllReadyWikiQueues() {
 171                 return [];
 172         }
 173
 174         protected function doPurge() {
 175                 return true;
 176         }
 177 }