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         /** @var string Wiki ID */
  38         protected $wiki;
  39
  40         /** @var array Map of (bucket => (queue => JobQueue, types => list of types) */
  41         protected $coalescedQueues;
  42
  43         const TYPE_DEFAULT = 1; // integer; jobs popped by default
  44         const TYPE_ANY = 2; // integer; any job
  45
  46         const USE_CACHE = 1; // integer; use process or persistent cache
  47         const USE_PRIORITY = 2; // integer; respect deprioritization
  48
  49         const PROC_CACHE_TTL = 15; // integer; seconds
  50
  51         const CACHE_VERSION = 1; // integer; cache version
  52
  53         /**
  54          * @param string $wiki Wiki ID
  55          */
  56         protected function __construct( $wiki ) {
  57                 $this->wiki = $wiki;
  58                 $this->cache = new ProcessCacheLRU( 10 );
  59         }
  60
  61         /**
  62          * @param bool|string $wiki Wiki ID
  63          * @return JobQueueGroup
  64          */
  65         public static function singleton( $wiki = false ) {
  66                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  67                 if ( !isset( self::$instances[$wiki] ) ) {
  68                         self::$instances[$wiki] = new self( $wiki );
  69                 }
  70
  71                 return self::$instances[$wiki];
  72         }
  73
  74         /**
  75          * Destroy the singleton instances
  76          *
  77          * @return void
  78          */
  79         public static function destroySingletons() {
  80                 self::$instances = array();
  81         }
  82
  83         /**
  84          * Get the job queue object for a given queue type
  85          *
  86          * @param string $type
  87          * @return JobQueue
  88          */
  89         public function get( $type ) {
  90                 global $wgJobTypeConf;
  91
  92                 $conf = array( 'wiki' => $this->wiki, 'type' => $type );
  93                 if ( isset( $wgJobTypeConf[$type] ) ) {
  94                         $conf = $conf + $wgJobTypeConf[$type];
  95                 } else {
  96                         $conf = $conf + $wgJobTypeConf['default'];
  97                 }
  98
  99                 return JobQueue::factory( $conf );
 100         }
 101
 102         /**
 103          * Insert jobs into the respective queues of with the belong.
 104          *
 105          * This inserts the jobs into the queue specified by $wgJobTypeConf
 106          * and updates the aggregate job queue information cache as needed.
 107          *
 108          * @param Job|array $jobs A single Job or a list of Jobs
 109          * @throws MWException
 110          * @return bool
 111          */
 112         public function push( $jobs ) {
 113                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 114                 if ( !count( $jobs ) ) {
 115                         return true;
 116                 }
 117
 118                 $jobsByType = array(); // (job type => list of jobs)
 119                 foreach ( $jobs as $job ) {
 120                         if ( $job instanceof Job ) {
 121                                 $jobsByType[$job->getType()][] = $job;
 122                         } else {
 123                                 throw new MWException( "Attempted to push a non-Job object into a queue." );
 124                         }
 125                 }
 126
 127                 $ok = true;
 128                 foreach ( $jobsByType as $type => $jobs ) {
 129                         if ( $this->get( $type )->push( $jobs ) ) {
 130                                 JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 131                         } else {
 132                                 $ok = false;
 133                         }
 134                 }
 135
 136                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 137                         $list = $this->cache->get( 'queues-ready', 'list' );
 138                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 139                                 $this->cache->clear( 'queues-ready' );
 140                         }
 141                 }
 142
 143                 return $ok;
 144         }
 145
 146         /**
 147          * Pop a job off one of the job queues
 148          *
 149          * This pops a job off a queue as specified by $wgJobTypeConf and
 150          * updates the aggregate job queue information cache as needed.
 151          *
 152          * @param int|string $qtype JobQueueGroup::TYPE_DEFAULT or type string
 153          * @param int $flags Bitfield of JobQueueGroup::USE_* constants
 154          * @return Job|bool Returns false on failure
 155          */
 156         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0 ) {
 157                 if ( is_string( $qtype ) ) { // specific job type
 158                         $job = $this->get( $qtype )->pop();
 159                         if ( !$job ) {
 160                                 JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $qtype );
 161                         }
 162
 163                         return $job;
 164                 } else { // any job in the "default" jobs types
 165                         if ( $flags & self::USE_CACHE ) {
 166                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 167                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 168                                 }
 169                                 $types = $this->cache->get( 'queues-ready', 'list' );
 170                         } else {
 171                                 $types = $this->getQueuesWithJobs();
 172                         }
 173
 174                         if ( $qtype == self::TYPE_DEFAULT ) {
 175                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 176                         }
 177                         shuffle( $types ); // avoid starvation
 178
 179                         foreach ( $types as $type ) { // for each queue...
 180                                 $job = $this->get( $type )->pop();
 181                                 if ( $job ) { // found
 182                                         return $job;
 183                                 } else { // not found
 184                                         JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $type );
 185                                         $this->cache->clear( 'queues-ready' );
 186                                 }
 187                         }
 188
 189                         return false; // no jobs found
 190                 }
 191         }
 192
 193         /**
 194          * Acknowledge that a job was completed
 195          *
 196          * @param Job $job
 197          * @return bool
 198          */
 199         public function ack( Job $job ) {
 200                 return $this->get( $job->getType() )->ack( $job );
 201         }
 202
 203         /**
 204          * Register the "root job" of a given job into the queue for de-duplication.
 205          * This should only be called right *after* all the new jobs have been inserted.
 206          *
 207          * @param Job $job
 208          * @return bool
 209          */
 210         public function deduplicateRootJob( Job $job ) {
 211                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 212         }
 213
 214         /**
 215          * Wait for any slaves or backup queue servers to catch up.
 216          *
 217          * This does nothing for certain queue classes.
 218          *
 219          * @return void
 220          * @throws MWException
 221          */
 222         public function waitForBackups() {
 223                 global $wgJobTypeConf;
 224
 225                 wfProfileIn( __METHOD__ );
 226                 // Try to avoid doing this more than once per queue storage medium
 227                 foreach ( $wgJobTypeConf as $type => $conf ) {
 228                         $this->get( $type )->waitForBackups();
 229                 }
 230                 wfProfileOut( __METHOD__ );
 231         }
 232
 233         /**
 234          * Get the list of queue types
 235          *
 236          * @return array List of strings
 237          */
 238         public function getQueueTypes() {
 239                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 240         }
 241
 242         /**
 243          * Get the list of default queue types
 244          *
 245          * @return array List of strings
 246          */
 247         public function getDefaultQueueTypes() {
 248                 global $wgJobTypesExcludedFromDefaultQueue;
 249
 250                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 251         }
 252
 253         /**
 254          * Get the list of job types that have non-empty queues
 255          *
 256          * @return array List of job types that have non-empty queues
 257          */
 258         public function getQueuesWithJobs() {
 259                 $types = array();
 260                 foreach ( $this->getCoalescedQueues() as $info ) {
 261                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 262                         if ( is_array( $nonEmpty ) ) { // batching features supported
 263                                 $types = array_merge( $types, $nonEmpty );
 264                         } else { // we have to go through the queues in the bucket one-by-one
 265                                 foreach ( $info['types'] as $type ) {
 266                                         if ( !$this->get( $type )->isEmpty() ) {
 267                                                 $types[] = $type;
 268                                         }
 269                                 }
 270                         }
 271                 }
 272
 273                 return $types;
 274         }
 275
 276         /**
 277          * Get the size of the queus for a list of job types
 278          *
 279          * @return array Map of (job type => size)
 280          */
 281         public function getQueueSizes() {
 282                 $sizeMap = array();
 283                 foreach ( $this->getCoalescedQueues() as $info ) {
 284                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 285                         if ( is_array( $sizes ) ) { // batching features supported
 286                                 $sizeMap = $sizeMap + $sizes;
 287                         } else { // we have to go through the queues in the bucket one-by-one
 288                                 foreach ( $info['types'] as $type ) {
 289                                         $sizeMap[$type] = $this->get( $type )->getSize();
 290                                 }
 291                         }
 292                 }
 293
 294                 return $sizeMap;
 295         }
 296
 297         /**
 298          * @return array
 299          */
 300         protected function getCoalescedQueues() {
 301                 global $wgJobTypeConf;
 302
 303                 if ( $this->coalescedQueues === null ) {
 304                         $this->coalescedQueues = array();
 305                         foreach ( $wgJobTypeConf as $type => $conf ) {
 306                                 $queue = JobQueue::factory(
 307                                         array( 'wiki' => $this->wiki, 'type' => 'null' ) + $conf );
 308                                 $loc = $queue->getCoalesceLocationInternal();
 309                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 310                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 311                                         $this->coalescedQueues[$loc]['types'] = array();
 312                                 }
 313                                 if ( $type === 'default' ) {
 314                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 315                                                 $this->coalescedQueues[$loc]['types'],
 316                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 317                                         );
 318                                 } else {
 319                                         $this->coalescedQueues[$loc]['types'][] = $type;
 320                                 }
 321                         }
 322                 }
 323
 324                 return $this->coalescedQueues;
 325         }
 326
 327         /**
 328          * Execute any due periodic queue maintenance tasks for all queues.
 329          *
 330          * A task is "due" if the time ellapsed since the last run is greater than
 331          * the defined run period. Concurrent calls to this function will cause tasks
 332          * to be attempted twice, so they may need their own methods of mutual exclusion.
 333          *
 334          * @return int Number of tasks run
 335          */
 336         public function executeReadyPeriodicTasks() {
 337                 global $wgMemc;
 338
 339                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 340                 $key = wfForeignMemcKey( $db, $prefix, 'jobqueuegroup', 'taskruns', 'v1' );
 341                 $lastRuns = $wgMemc->get( $key ); // (queue => task => UNIX timestamp)
 342
 343                 $count = 0;
 344                 $tasksRun = array(); // (queue => task => UNIX timestamp)
 345                 foreach ( $this->getQueueTypes() as $type ) {
 346                         $queue = $this->get( $type );
 347                         foreach ( $queue->getPeriodicTasks() as $task => $definition ) {
 348                                 if ( $definition['period'] <= 0 ) {
 349                                         continue; // disabled
 350                                 } elseif ( !isset( $lastRuns[$type][$task] )
 351                                         || $lastRuns[$type][$task] < ( time() - $definition['period'] )
 352                                 ) {
 353                                         try {
 354                                                 if ( call_user_func( $definition['callback'] ) !== null ) {
 355                                                         $tasksRun[$type][$task] = time();
 356                                                         ++$count;
 357                                                 }
 358                                         } catch ( JobQueueError $e ) {
 359                                                 MWExceptionHandler::logException( $e );
 360                                         }
 361                                 }
 362                         }
 363                         // The tasks may have recycled jobs or release delayed jobs into the queue
 364                         if ( isset( $tasksRun[$type] ) && !$queue->isEmpty() ) {
 365                                 JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 366                         }
 367                 }
 368
 369                 $wgMemc->merge( $key, function ( $cache, $key, $lastRuns ) use ( $tasksRun ) {
 370                         if ( is_array( $lastRuns ) ) {
 371                                 foreach ( $tasksRun as $type => $tasks ) {
 372                                         foreach ( $tasks as $task => $timestamp ) {
 373                                                 if ( !isset( $lastRuns[$type][$task] )
 374                                                         || $timestamp > $lastRuns[$type][$task]
 375                                                 ) {
 376                                                         $lastRuns[$type][$task] = $timestamp;
 377                                                 }
 378                                         }
 379                                 }
 380                         } else {
 381                                 $lastRuns = $tasksRun;
 382                         }
 383
 384                         return $lastRuns;
 385                 } );
 386
 387                 return $count;
 388         }
 389
 390         /**
 391          * @param $name string
 392          * @return mixed
 393          */
 394         private function getCachedConfigVar( $name ) {
 395                 global $wgConf, $wgMemc;
 396
 397                 if ( $this->wiki === wfWikiID() ) {
 398                         return $GLOBALS[$name]; // common case
 399                 } else {
 400                         list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 401                         $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
 402                         $value = $wgMemc->get( $key ); // ('v' => ...) or false
 403                         if ( is_array( $value ) ) {
 404                                 return $value['v'];
 405                         } else {
 406                                 $value = $wgConf->getConfig( $this->wiki, $name );
 407                                 $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
 408
 409                                 return $value;
 410                         }
 411                 }
 412         }
 413 }