includes/jobqueue/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
  48         const PROC_CACHE_TTL = 15; // integer; seconds
  49
  50         const CACHE_VERSION = 1; // integer; cache version
  51
  52         /**
  53          * @param string $wiki Wiki ID
  54          */
  55         protected function __construct( $wiki ) {
  56                 $this->wiki = $wiki;
  57                 $this->cache = new ProcessCacheLRU( 10 );
  58         }
  59
  60         /**
  61          * @param bool|string $wiki Wiki ID
  62          * @return JobQueueGroup
  63          */
  64         public static function singleton( $wiki = false ) {
  65                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  66                 if ( !isset( self::$instances[$wiki] ) ) {
  67                         self::$instances[$wiki] = new self( $wiki );
  68                 }
  69
  70                 return self::$instances[$wiki];
  71         }
  72
  73         /**
  74          * Destroy the singleton instances
  75          *
  76          * @return void
  77          */
  78         public static function destroySingletons() {
  79                 self::$instances = array();
  80         }
  81
  82         /**
  83          * Get the job queue object for a given queue type
  84          *
  85          * @param string $type
  86          * @return JobQueue
  87          */
  88         public function get( $type ) {
  89                 global $wgJobTypeConf;
  90
  91                 $conf = array( 'wiki' => $this->wiki, 'type' => $type );
  92                 if ( isset( $wgJobTypeConf[$type] ) ) {
  93                         $conf = $conf + $wgJobTypeConf[$type];
  94                 } else {
  95                         $conf = $conf + $wgJobTypeConf['default'];
  96                 }
  97
  98                 return JobQueue::factory( $conf );
  99         }
 100
 101         /**
 102          * Insert jobs into the respective queues of with the belong.
 103          *
 104          * This inserts the jobs into the queue specified by $wgJobTypeConf
 105          * and updates the aggregate job queue information cache as needed.
 106          *
 107          * @param Job|Job[] $jobs A single Job or a list of Jobs
 108          * @throws MWException
 109          * @return void
 110          */
 111         public function push( $jobs ) {
 112                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 113                 if ( !count( $jobs ) ) {
 114                         return;
 115                 }
 116
 117                 $jobsByType = array(); // (job type => list of jobs)
 118                 foreach ( $jobs as $job ) {
 119                         if ( $job instanceof IJobSpecification ) {
 120                                 $jobsByType[$job->getType()][] = $job;
 121                         } else {
 122                                 throw new MWException( "Attempted to push a non-Job object into a queue." );
 123                         }
 124                 }
 125
 126                 foreach ( $jobsByType as $type => $jobs ) {
 127                         $this->get( $type )->push( $jobs );
 128                         JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 129                 }
 130
 131                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 132                         $list = $this->cache->get( 'queues-ready', 'list' );
 133                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 134                                 $this->cache->clear( 'queues-ready' );
 135                         }
 136                 }
 137         }
 138
 139         /**
 140          * Pop a job off one of the job queues
 141          *
 142          * This pops a job off a queue as specified by $wgJobTypeConf and
 143          * updates the aggregate job queue information cache as needed.
 144          *
 145          * @param int|string $qtype JobQueueGroup::TYPE_* constant or job type string
 146          * @param int $flags Bitfield of JobQueueGroup::USE_* constants
 147          * @param array $blacklist List of job types to ignore
 148          * @return Job|bool Returns false on failure
 149          */
 150         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0, array $blacklist = array() ) {
 151                 $job = false;
 152
 153                 if ( is_string( $qtype ) ) { // specific job type
 154                         if ( !in_array( $qtype, $blacklist ) ) {
 155                                 $job = $this->get( $qtype )->pop();
 156                                 if ( !$job ) {
 157                                         JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $qtype );
 158                                 }
 159                         }
 160                 } else { // any job in the "default" jobs types
 161                         if ( $flags & self::USE_CACHE ) {
 162                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 163                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 164                                 }
 165                                 $types = $this->cache->get( 'queues-ready', 'list' );
 166                         } else {
 167                                 $types = $this->getQueuesWithJobs();
 168                         }
 169
 170                         if ( $qtype == self::TYPE_DEFAULT ) {
 171                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 172                         }
 173
 174                         $types = array_diff( $types, $blacklist ); // avoid selected types
 175                         shuffle( $types ); // avoid starvation
 176
 177                         foreach ( $types as $type ) { // for each queue...
 178                                 $job = $this->get( $type )->pop();
 179                                 if ( $job ) { // found
 180                                         break;
 181                                 } else { // not found
 182                                         JobQueueAggregator::singleton()->notifyQueueEmpty( $this->wiki, $type );
 183                                         $this->cache->clear( 'queues-ready' );
 184                                 }
 185                         }
 186                 }
 187
 188                 return $job;
 189         }
 190
 191         /**
 192          * Acknowledge that a job was completed
 193          *
 194          * @param Job $job
 195          * @return bool
 196          */
 197         public function ack( Job $job ) {
 198                 return $this->get( $job->getType() )->ack( $job );
 199         }
 200
 201         /**
 202          * Register the "root job" of a given job into the queue for de-duplication.
 203          * This should only be called right *after* all the new jobs have been inserted.
 204          *
 205          * @param Job $job
 206          * @return bool
 207          */
 208         public function deduplicateRootJob( Job $job ) {
 209                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 210         }
 211
 212         /**
 213          * Wait for any slaves or backup queue servers to catch up.
 214          *
 215          * This does nothing for certain queue classes.
 216          *
 217          * @return void
 218          * @throws MWException
 219          */
 220         public function waitForBackups() {
 221                 global $wgJobTypeConf;
 222
 223                 wfProfileIn( __METHOD__ );
 224                 // Try to avoid doing this more than once per queue storage medium
 225                 foreach ( $wgJobTypeConf as $type => $conf ) {
 226                         $this->get( $type )->waitForBackups();
 227                 }
 228                 wfProfileOut( __METHOD__ );
 229         }
 230
 231         /**
 232          * Get the list of queue types
 233          *
 234          * @return array List of strings
 235          */
 236         public function getQueueTypes() {
 237                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 238         }
 239
 240         /**
 241          * Get the list of default queue types
 242          *
 243          * @return array List of strings
 244          */
 245         public function getDefaultQueueTypes() {
 246                 global $wgJobTypesExcludedFromDefaultQueue;
 247
 248                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 249         }
 250
 251         /**
 252          * Check if there are any queues with jobs (this is cached)
 253          *
 254          * @param int $type JobQueueGroup::TYPE_* constant
 255          * @return bool
 256          * @since 1.23
 257          */
 258         public function queuesHaveJobs( $type = self::TYPE_ANY ) {
 259                 global $wgMemc;
 260
 261                 $key = wfMemcKey( 'jobqueue', 'queueshavejobs', $type );
 262
 263                 $value = $wgMemc->get( $key );
 264                 if ( $value === false ) {
 265                         $queues = $this->getQueuesWithJobs();
 266                         if ( $type == self::TYPE_DEFAULT ) {
 267                                 $queues = array_intersect( $queues, $this->getDefaultQueueTypes() );
 268                         }
 269                         $value = count( $queues ) ? 'true' : 'false';
 270                         $wgMemc->add( $key, $value, 15 );
 271                 }
 272
 273                 return ( $value === 'true' );
 274         }
 275
 276         /**
 277          * Get the list of job types that have non-empty queues
 278          *
 279          * @return array List of job types that have non-empty queues
 280          */
 281         public function getQueuesWithJobs() {
 282                 $types = array();
 283                 foreach ( $this->getCoalescedQueues() as $info ) {
 284                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 285                         if ( is_array( $nonEmpty ) ) { // batching features supported
 286                                 $types = array_merge( $types, $nonEmpty );
 287                         } else { // we have to go through the queues in the bucket one-by-one
 288                                 foreach ( $info['types'] as $type ) {
 289                                         if ( !$this->get( $type )->isEmpty() ) {
 290                                                 $types[] = $type;
 291                                         }
 292                                 }
 293                         }
 294                 }
 295
 296                 return $types;
 297         }
 298
 299         /**
 300          * Get the size of the queus for a list of job types
 301          *
 302          * @return array Map of (job type => size)
 303          */
 304         public function getQueueSizes() {
 305                 $sizeMap = array();
 306                 foreach ( $this->getCoalescedQueues() as $info ) {
 307                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 308                         if ( is_array( $sizes ) ) { // batching features supported
 309                                 $sizeMap = $sizeMap + $sizes;
 310                         } else { // we have to go through the queues in the bucket one-by-one
 311                                 foreach ( $info['types'] as $type ) {
 312                                         $sizeMap[$type] = $this->get( $type )->getSize();
 313                                 }
 314                         }
 315                 }
 316
 317                 return $sizeMap;
 318         }
 319
 320         /**
 321          * @return array
 322          */
 323         protected function getCoalescedQueues() {
 324                 global $wgJobTypeConf;
 325
 326                 if ( $this->coalescedQueues === null ) {
 327                         $this->coalescedQueues = array();
 328                         foreach ( $wgJobTypeConf as $type => $conf ) {
 329                                 $queue = JobQueue::factory(
 330                                         array( 'wiki' => $this->wiki, 'type' => 'null' ) + $conf );
 331                                 $loc = $queue->getCoalesceLocationInternal();
 332                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 333                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 334                                         $this->coalescedQueues[$loc]['types'] = array();
 335                                 }
 336                                 if ( $type === 'default' ) {
 337                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 338                                                 $this->coalescedQueues[$loc]['types'],
 339                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 340                                         );
 341                                 } else {
 342                                         $this->coalescedQueues[$loc]['types'][] = $type;
 343                                 }
 344                         }
 345                 }
 346
 347                 return $this->coalescedQueues;
 348         }
 349
 350         /**
 351          * Execute any due periodic queue maintenance tasks for all queues.
 352          *
 353          * A task is "due" if the time ellapsed since the last run is greater than
 354          * the defined run period. Concurrent calls to this function will cause tasks
 355          * to be attempted twice, so they may need their own methods of mutual exclusion.
 356          *
 357          * @return int Number of tasks run
 358          */
 359         public function executeReadyPeriodicTasks() {
 360                 global $wgMemc;
 361
 362                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 363                 $key = wfForeignMemcKey( $db, $prefix, 'jobqueuegroup', 'taskruns', 'v1' );
 364                 $lastRuns = $wgMemc->get( $key ); // (queue => task => UNIX timestamp)
 365
 366                 $count = 0;
 367                 $tasksRun = array(); // (queue => task => UNIX timestamp)
 368                 foreach ( $this->getQueueTypes() as $type ) {
 369                         $queue = $this->get( $type );
 370                         foreach ( $queue->getPeriodicTasks() as $task => $definition ) {
 371                                 if ( $definition['period'] <= 0 ) {
 372                                         continue; // disabled
 373                                 } elseif ( !isset( $lastRuns[$type][$task] )
 374                                         || $lastRuns[$type][$task] < ( time() - $definition['period'] )
 375                                 ) {
 376                                         try {
 377                                                 if ( call_user_func( $definition['callback'] ) !== null ) {
 378                                                         $tasksRun[$type][$task] = time();
 379                                                         ++$count;
 380                                                 }
 381                                         } catch ( JobQueueError $e ) {
 382                                                 MWExceptionHandler::logException( $e );
 383                                         }
 384                                 }
 385                         }
 386                         // The tasks may have recycled jobs or release delayed jobs into the queue
 387                         if ( isset( $tasksRun[$type] ) && !$queue->isEmpty() ) {
 388                                 JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 389                         }
 390                 }
 391
 392                 if ( $count === 0 ) {
 393                         return $count; // nothing to update
 394                 }
 395
 396                 $wgMemc->merge( $key, function ( $cache, $key, $lastRuns ) use ( $tasksRun ) {
 397                         if ( is_array( $lastRuns ) ) {
 398                                 foreach ( $tasksRun as $type => $tasks ) {
 399                                         foreach ( $tasks as $task => $timestamp ) {
 400                                                 if ( !isset( $lastRuns[$type][$task] )
 401                                                         || $timestamp > $lastRuns[$type][$task]
 402                                                 ) {
 403                                                         $lastRuns[$type][$task] = $timestamp;
 404                                                 }
 405                                         }
 406                                 }
 407                         } else {
 408                                 $lastRuns = $tasksRun;
 409                         }
 410
 411                         return $lastRuns;
 412                 } );
 413
 414                 return $count;
 415         }
 416
 417         /**
 418          * @param string $name
 419          * @return mixed
 420          */
 421         private function getCachedConfigVar( $name ) {
 422                 global $wgConf, $wgMemc;
 423
 424                 if ( $this->wiki === wfWikiID() ) {
 425                         return $GLOBALS[$name]; // common case
 426                 } else {
 427                         list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 428                         $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
 429                         $value = $wgMemc->get( $key ); // ('v' => ...) or false
 430                         if ( is_array( $value ) ) {
 431                                 return $value['v'];
 432                         } else {
 433                                 $value = $wgConf->getConfig( $this->wiki, $name );
 434                                 $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
 435
 436                                 return $value;
 437                         }
 438                 }
 439         }
 440 }