includes/job/JobQueueGroup.php

   1 <?php
   2 /**
   3  * Job queue base 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 enqueueing of background jobs
  26  *
  27  * @ingroup JobQueue
  28  * @since 1.21
  29  */
  30 class JobQueueGroup {
  31         /** @var Array */
  32         protected static $instances = array();
  33
  34         /** @var ProcessCacheLRU */
  35         protected $cache;
  36
  37         protected $wiki; // string; wiki ID
  38
  39         const TYPE_DEFAULT = 1; // integer; jobs popped by default
  40         const TYPE_ANY     = 2; // integer; any job
  41
  42         const USE_CACHE = 1; // integer; use process cache
  43
  44         const PROC_CACHE_TTL = 15; // integer; seconds
  45
  46         /**
  47          * @param $wiki string Wiki ID
  48          */
  49         protected function __construct( $wiki ) {
  50                 $this->wiki = $wiki;
  51                 $this->cache = new ProcessCacheLRU( 1 );
  52         }
  53
  54         /**
  55          * @param $wiki string Wiki ID
  56          * @return JobQueueGroup
  57          */
  58         public static function singleton( $wiki = false ) {
  59                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  60                 if ( !isset( self::$instances[$wiki] ) ) {
  61                         self::$instances[$wiki] = new self( $wiki );
  62                 }
  63                 return self::$instances[$wiki];
  64         }
  65
  66         /**
  67          * Destroy the singleton instances
  68          *
  69          * @return void
  70          */
  71         public static function destroySingletons() {
  72                 self::$instances = array();
  73         }
  74
  75         /**
  76          * @param $type string
  77          * @return JobQueue Job queue object for a given queue type
  78          */
  79         public function get( $type ) {
  80                 global $wgJobTypeConf;
  81
  82                 $conf = array( 'wiki' => $this->wiki, 'type' => $type );
  83                 if ( isset( $wgJobTypeConf[$type] ) ) {
  84                         $conf = $conf + $wgJobTypeConf[$type];
  85                 } else {
  86                         $conf = $conf + $wgJobTypeConf['default'];
  87                 }
  88
  89                 return JobQueue::factory( $conf );
  90         }
  91
  92         /**
  93          * Insert jobs into the respective queues of with the belong.
  94          * This inserts the jobs into the queue specified by $wgJobTypeConf.
  95          *
  96          * @param $jobs Job|array A single Job or a list of Jobs
  97          * @throws MWException
  98          * @return bool
  99          */
 100         public function push( $jobs ) {
 101                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 102
 103                 $jobsByType = array(); // (job type => list of jobs)
 104                 foreach ( $jobs as $job ) {
 105                         if ( $job instanceof Job ) {
 106                                 $jobsByType[$job->getType()][] = $job;
 107                         } else {
 108                                 throw new MWException( "Attempted to push a non-Job object into a queue." );
 109                         }
 110                 }
 111
 112                 $ok = true;
 113                 foreach ( $jobsByType as $type => $jobs ) {
 114                         if ( !$this->get( $type )->push( $jobs ) ) {
 115                                 $ok = false;
 116                         }
 117                 }
 118
 119                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 120                         $list = $this->cache->get( 'queues-ready', 'list' );
 121                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 122                                 $this->cache->clear( 'queues-ready' );
 123                         }
 124                 }
 125
 126                 return $ok;
 127         }
 128
 129         /**
 130          * Pop a job off one of the job queues
 131          *
 132          * @param $queueType integer JobQueueGroup::TYPE_* constant
 133          * @param $flags integer Bitfield of JobQueueGroup::USE_* constants
 134          * @return Job|bool Returns false on failure
 135          */
 136         public function pop( $queueType = self::TYPE_DEFAULT, $flags = 0 ) {
 137                 if ( $flags & self::USE_CACHE ) {
 138                         if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 139                                 $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 140                         }
 141                         $types = $this->cache->get( 'queues-ready', 'list' );
 142                 } else {
 143                         $types = $this->getQueuesWithJobs();
 144                 }
 145
 146                 if ( $queueType == self::TYPE_DEFAULT ) {
 147                         $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 148                 }
 149                 shuffle( $types ); // avoid starvation
 150
 151                 foreach ( $types as $type ) { // for each queue...
 152                         $job = $this->get( $type )->pop();
 153                         if ( $job ) { // found
 154                                 return $job;
 155                         } else { // not found
 156                                 $this->cache->clear( 'queues-ready' );
 157                         }
 158                 }
 159
 160                 return false; // no jobs found
 161         }
 162
 163         /**
 164          * Acknowledge that a job was completed
 165          *
 166          * @param $job Job
 167          * @return bool
 168          */
 169         public function ack( Job $job ) {
 170                 return $this->get( $job->getType() )->ack( $job );
 171         }
 172
 173         /**
 174          * Register the "root job" of a given job into the queue for de-duplication.
 175          * This should only be called right *after* all the new jobs have been inserted.
 176          *
 177          * @param $job Job
 178          * @return bool
 179          */
 180         public function deduplicateRootJob( Job $job ) {
 181                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 182         }
 183
 184         /**
 185          * Get the list of queue types
 186          *
 187          * @return array List of strings
 188          */
 189         public function getQueueTypes() {
 190                 global $wgJobClasses;
 191
 192                 return array_keys( $wgJobClasses );
 193         }
 194
 195         /**
 196          * Get the list of default queue types
 197          *
 198          * @return array List of strings
 199          */
 200         public function getDefaultQueueTypes() {
 201                 global $wgJobTypesExcludedFromDefaultQueue;
 202
 203                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 204         }
 205
 206         /**
 207          * @return Array List of job types that have non-empty queues
 208          */
 209         public function getQueuesWithJobs() {
 210                 $types = array();
 211                 foreach ( $this->getQueueTypes() as $type ) {
 212                         if ( !$this->get( $type )->isEmpty() ) {
 213                                 $types[] = $type;
 214                         }
 215                 }
 216                 return $types;
 217         }
 218
 219         /**
 220          * @return Array List of default job types that have non-empty queues
 221          */
 222         public function getDefaultQueuesWithJobs() {
 223                 $types = array();
 224                 foreach ( $this->getDefaultQueueTypes() as $type ) {
 225                         if ( !$this->get( $type )->isEmpty() ) {
 226                                 $types[] = $type;
 227                         }
 228                 }
 229                 return $types;
 230         }
 231 }