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         protected 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                 wfProfileIn( __METHOD__ );
  77                 $ok = $this->doNotifyQueueEmpty( $wiki, $type );
  78                 wfProfileOut( __METHOD__ );
  79
  80                 return $ok;
  81         }
  82
  83         /**
  84          * @see JobQueueAggregator::notifyQueueEmpty()
  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                 wfProfileIn( __METHOD__ );
  97                 $ok = $this->doNotifyQueueNonEmpty( $wiki, $type );
  98                 wfProfileOut( __METHOD__ );
  99
 100                 return $ok;
 101         }
 102
 103         /**
 104          * @see JobQueueAggregator::notifyQueueNonEmpty()
 105          */
 106         abstract protected function doNotifyQueueNonEmpty( $wiki, $type );
 107
 108         /**
 109          * Get the list of all of the queues with jobs
 110          *
 111          * @return array (job type => (list of wiki IDs))
 112          */
 113         final public function getAllReadyWikiQueues() {
 114                 wfProfileIn( __METHOD__ );
 115                 $res = $this->doGetAllReadyWikiQueues();
 116                 wfProfileOut( __METHOD__ );
 117
 118                 return $res;
 119         }
 120
 121         /**
 122          * @see JobQueueAggregator::getAllReadyWikiQueues()
 123          */
 124         abstract protected function doGetAllReadyWikiQueues();
 125
 126         /**
 127          * Purge all of the aggregator information
 128          *
 129          * @return bool Success
 130          */
 131         final public function purge() {
 132                 wfProfileIn( __METHOD__ );
 133                 $res = $this->doPurge();
 134                 wfProfileOut( __METHOD__ );
 135
 136                 return $res;
 137         }
 138
 139         /**
 140          * @see JobQueueAggregator::purge()
 141          */
 142         abstract protected function doPurge();
 143
 144         /**
 145          * Get all databases that have a pending job.
 146          * This poll all the queues and is this expensive.
 147          *
 148          * @return array (job type => (list of wiki IDs))
 149          */
 150         protected function findPendingWikiQueues() {
 151                 global $wgLocalDatabases;
 152
 153                 $pendingDBs = array(); // (job type => (db list))
 154                 foreach ( $wgLocalDatabases as $db ) {
 155                         foreach ( JobQueueGroup::singleton( $db )->getQueuesWithJobs() as $type ) {
 156                                 $pendingDBs[$type][] = $db;
 157                         }
 158                 }
 159
 160                 return $pendingDBs;
 161         }
 162 }