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 or persistent cache
  43
  44         const PROC_CACHE_TTL = 15; // integer; seconds
  45
  46         const CACHE_VERSION = 1; // integer; cache version
  47
  48         /**
  49          * @param $wiki string Wiki ID
  50          */
  51         protected function __construct( $wiki ) {
  52                 $this->wiki = $wiki;
  53                 $this->cache = new ProcessCacheLRU( 10 );
  54         }
  55
  56         /**
  57          * @param $wiki string Wiki ID
  58          * @return JobQueueGroup
  59          */
  60         public static function singleton( $wiki = false ) {
  61                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  62                 if ( !isset( self::$instances[$wiki] ) ) {
  63                         self::$instances[$wiki] = new self( $wiki );
  64                 }
  65                 return self::$instances[$wiki];
  66         }
  67
  68         /**
  69          * Destroy the singleton instances
  70          *
  71          * @return void
  72          */
  73         public static function destroySingletons() {
  74                 self::$instances = array();
  75         }
  76
  77         /**
  78          * Get the job queue object for a given queue type
  79          *
  80          * @param $type string
  81          * @return JobQueue
  82          */
  83         public function get( $type ) {
  84                 global $wgJobTypeConf;
  85
  86                 $conf = array( 'wiki' => $this->wiki, 'type' => $type );
  87                 if ( isset( $wgJobTypeConf[$type] ) ) {
  88                         $conf = $conf + $wgJobTypeConf[$type];
  89                 } else {
  90                         $conf = $conf + $wgJobTypeConf['default'];
  91                 }
  92
  93                 return JobQueue::factory( $conf );
  94         }
  95
  96         /**
  97          * Insert jobs into the respective queues of with the belong.
  98          *
  99          * This inserts the jobs into the queue specified by $wgJobTypeConf
 100          * and updates the aggregate job queue information cache as needed.
 101          *
 102          * @param $jobs Job|array A single Job or a list of Jobs
 103          * @throws MWException
 104          * @return bool
 105          */
 106         public function push( $jobs ) {
 107                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 108
 109                 $jobsByType = array(); // (job type => list of jobs)
 110                 foreach ( $jobs as $job ) {
 111                         if ( $job instanceof Job ) {
 112                                 $jobsByType[$job->getType()][] = $job;
 113                         } else {
 114                                 throw new MWException( "Attempted to push a non-Job object into a queue." );
 115                         }
 116                 }
 117
 118                 $ok = true;
 119                 foreach ( $jobsByType as $type => $jobs ) {
 120                         if ( $this->get( $type )->push( $jobs ) ) {
 121                                 JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 122                         } else {
 123                                 $ok = false;
 124                         }
 125                 }
 126
 127                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 128                         $list = $this->cache->get( 'queues-ready', 'list' );
 129                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 130                                 $this->cache->clear( 'queues-ready' );
 131                         }
 132                 }
 133
 134                 return $ok;
 135         }
 136
 137         /**
 138          * Pop a job off one of the job queues
 139          *
 140          * This pops a job off a queue as specified by $wgJobTypeConf and
 141          * updates the aggregate job queue information cache as needed.
 142          *
 143          * @param $qtype integer|string JobQueueGroup::TYPE_DEFAULT or type string
 144          * @param $flags integer Bitfield of JobQueueGroup::USE_* constants
 145          * @return Job|bool Returns false on failure
 146          */
 147         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0 ) {
 148                 if ( is_string( $qtype ) ) { // specific job type
 149                         $job = $this->get( $qtype )->pop();
 150                         if ( !$job ) {
 151                                 JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $qtype );
 152                         }
 153                         return $job;
 154                 } else { // any job in the "default" jobs types
 155                         if ( $flags & self::USE_CACHE ) {
 156                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 157                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 158                                 }
 159                                 $types = $this->cache->get( 'queues-ready', 'list' );
 160                         } else {
 161                                 $types = $this->getQueuesWithJobs();
 162                         }
 163
 164                         if ( $qtype == self::TYPE_DEFAULT ) {
 165                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 166                         }
 167                         shuffle( $types ); // avoid starvation
 168
 169                         foreach ( $types as $type ) { // for each queue...
 170                                 $job = $this->get( $type )->pop();
 171                                 if ( $job ) { // found
 172                                         return $job;
 173                                 } else { // not found
 174                                         JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $type );
 175                                         $this->cache->clear( 'queues-ready' );
 176                                 }
 177                         }
 178
 179                         return false; // no jobs found
 180                 }
 181         }
 182
 183         /**
 184          * Acknowledge that a job was completed
 185          *
 186          * @param $job Job
 187          * @return bool
 188          */
 189         public function ack( Job $job ) {
 190                 return $this->get( $job->getType() )->ack( $job );
 191         }
 192
 193         /**
 194          * Register the "root job" of a given job into the queue for de-duplication.
 195          * This should only be called right *after* all the new jobs have been inserted.
 196          *
 197          * @param $job Job
 198          * @return bool
 199          */
 200         public function deduplicateRootJob( Job $job ) {
 201                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 202         }
 203
 204         /**
 205          * Get the list of queue types
 206          *
 207          * @return array List of strings
 208          */
 209         public function getQueueTypes() {
 210                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 211         }
 212
 213         /**
 214          * Get the list of default queue types
 215          *
 216          * @return array List of strings
 217          */
 218         public function getDefaultQueueTypes() {
 219                 global $wgJobTypesExcludedFromDefaultQueue;
 220
 221                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 222         }
 223
 224         /**
 225          * Get the list of job types that have non-empty queues
 226          *
 227          * @return Array List of job types that have non-empty queues
 228          */
 229         public function getQueuesWithJobs() {
 230                 $types = array();
 231                 foreach ( $this->getQueueTypes() as $type ) {
 232                         if ( !$this->get( $type )->isEmpty() ) {
 233                                 $types[] = $type;
 234                         }
 235                 }
 236                 return $types;
 237         }
 238
 239         /**
 240          * Check if jobs should not be popped of a queue right now.
 241          * This is only used for performance, such as to avoid spamming
 242          * the queue with many sub-jobs before they actually get run.
 243          *
 244          * @param $type string
 245          * @return bool
 246          */
 247         public function isQueueDeprioritized( $type ) {
 248                 if ( $type === 'refreshLinks2' ) {
 249                         // Don't keep converting refreshLinks2 => refreshLinks jobs if the
 250                         // later jobs have not been done yet. This helps throttle queue spam.
 251                         return !$this->get( 'refreshLinks' )->isEmpty();
 252                 }
 253                 return false;
 254         }
 255
 256         /**
 257          * Execute any due periodic queue maintenance tasks for all queues.
 258          *
 259          * A task is "due" if the time ellapsed since the last run is greater than
 260          * the defined run period. Concurrent calls to this function will cause tasks
 261          * to be attempted twice, so they may need their own methods of mutual exclusion.
 262          *
 263          * @return integer Number of tasks run
 264          */
 265         public function executeReadyPeriodicTasks() {
 266                 global $wgMemc;
 267
 268                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 269                 $key = wfForeignMemcKey( $db, $prefix, 'jobqueuegroup', 'taskruns', 'v1' );
 270                 $lastRuns = $wgMemc->get( $key ); // (queue => task => UNIX timestamp)
 271
 272                 $count = 0;
 273                 $tasksRun = array(); // (queue => task => UNIX timestamp)
 274                 foreach ( $this->getQueueTypes() as $type ) {
 275                         $queue = $this->get( $type );
 276                         foreach ( $queue->getPeriodicTasks() as $task => $definition ) {
 277                                 if ( $definition['period'] <= 0 ) {
 278                                         continue; // disabled
 279                                 } elseif ( !isset( $lastRuns[$type][$task] )
 280                                         || $lastRuns[$type][$task] < ( time() - $definition['period'] ) )
 281                                 {
 282                                         if ( call_user_func( $definition['callback'] ) !== null ) {
 283                                                 $tasksRun[$type][$task] = time();
 284                                                 ++$count;
 285                                         }
 286                                 }
 287                         }
 288                 }
 289
 290                 $wgMemc->merge( $key, function( $cache, $key, $lastRuns ) use ( $tasksRun ) {
 291                         if ( is_array( $lastRuns ) ) {
 292                                 foreach ( $tasksRun as $type => $tasks ) {
 293                                         foreach ( $tasks as $task => $timestamp ) {
 294                                                 if ( !isset( $lastRuns[$type][$task] )
 295                                                         || $timestamp > $lastRuns[$type][$task] )
 296                                                 {
 297                                                         $lastRuns[$type][$task] = $timestamp;
 298                                                 }
 299                                         }
 300                                 }
 301                         } else {
 302                                 $lastRuns = $tasksRun;
 303                         }
 304                         return $lastRuns;
 305                 } );
 306
 307                 return $count;
 308         }
 309
 310         /**
 311          * @param $name string
 312          * @return mixed
 313          */
 314         private function getCachedConfigVar( $name ) {
 315                 global $wgConf, $wgMemc;
 316
 317                 if ( $this->wiki === wfWikiID() ) {
 318                         return $GLOBALS[$name]; // common case
 319                 } else {
 320                         list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 321                         $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
 322                         $value = $wgMemc->get( $key ); // ('v' => ...) or false
 323                         if ( is_array( $value ) ) {
 324                                 return $value['v'];
 325                         } else {
 326                                 $value = $wgConf->getConfig( $this->wiki, $name );
 327                                 $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
 328                                 return $value;
 329                         }
 330                 }
 331         }
 332 }