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                 // Try to avoid doing this more than once per queue storage medium
 224                 foreach ( $wgJobTypeConf as $type => $conf ) {
 225                         $this->get( $type )->waitForBackups();
 226                 }
 227         }
 228
 229         /**
 230          * Get the list of queue types
 231          *
 232          * @return array List of strings
 233          */
 234         public function getQueueTypes() {
 235                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 236         }
 237
 238         /**
 239          * Get the list of default queue types
 240          *
 241          * @return array List of strings
 242          */
 243         public function getDefaultQueueTypes() {
 244                 global $wgJobTypesExcludedFromDefaultQueue;
 245
 246                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 247         }
 248
 249         /**
 250          * Check if there are any queues with jobs (this is cached)
 251          *
 252          * @param int $type JobQueueGroup::TYPE_* constant
 253          * @return bool
 254          * @since 1.23
 255          */
 256         public function queuesHaveJobs( $type = self::TYPE_ANY ) {
 257                 global $wgMemc;
 258
 259                 $key = wfMemcKey( 'jobqueue', 'queueshavejobs', $type );
 260
 261                 $value = $wgMemc->get( $key );
 262                 if ( $value === false ) {
 263                         $queues = $this->getQueuesWithJobs();
 264                         if ( $type == self::TYPE_DEFAULT ) {
 265                                 $queues = array_intersect( $queues, $this->getDefaultQueueTypes() );
 266                         }
 267                         $value = count( $queues ) ? 'true' : 'false';
 268                         $wgMemc->add( $key, $value, 15 );
 269                 }
 270
 271                 return ( $value === 'true' );
 272         }
 273
 274         /**
 275          * Get the list of job types that have non-empty queues
 276          *
 277          * @return array List of job types that have non-empty queues
 278          */
 279         public function getQueuesWithJobs() {
 280                 $types = array();
 281                 foreach ( $this->getCoalescedQueues() as $info ) {
 282                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 283                         if ( is_array( $nonEmpty ) ) { // batching features supported
 284                                 $types = array_merge( $types, $nonEmpty );
 285                         } else { // we have to go through the queues in the bucket one-by-one
 286                                 foreach ( $info['types'] as $type ) {
 287                                         if ( !$this->get( $type )->isEmpty() ) {
 288                                                 $types[] = $type;
 289                                         }
 290                                 }
 291                         }
 292                 }
 293
 294                 return $types;
 295         }
 296
 297         /**
 298          * Get the size of the queus for a list of job types
 299          *
 300          * @return array Map of (job type => size)
 301          */
 302         public function getQueueSizes() {
 303                 $sizeMap = array();
 304                 foreach ( $this->getCoalescedQueues() as $info ) {
 305                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 306                         if ( is_array( $sizes ) ) { // batching features supported
 307                                 $sizeMap = $sizeMap + $sizes;
 308                         } else { // we have to go through the queues in the bucket one-by-one
 309                                 foreach ( $info['types'] as $type ) {
 310                                         $sizeMap[$type] = $this->get( $type )->getSize();
 311                                 }
 312                         }
 313                 }
 314
 315                 return $sizeMap;
 316         }
 317
 318         /**
 319          * @return array
 320          */
 321         protected function getCoalescedQueues() {
 322                 global $wgJobTypeConf;
 323
 324                 if ( $this->coalescedQueues === null ) {
 325                         $this->coalescedQueues = array();
 326                         foreach ( $wgJobTypeConf as $type => $conf ) {
 327                                 $queue = JobQueue::factory(
 328                                         array( 'wiki' => $this->wiki, 'type' => 'null' ) + $conf );
 329                                 $loc = $queue->getCoalesceLocationInternal();
 330                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 331                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 332                                         $this->coalescedQueues[$loc]['types'] = array();
 333                                 }
 334                                 if ( $type === 'default' ) {
 335                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 336                                                 $this->coalescedQueues[$loc]['types'],
 337                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 338                                         );
 339                                 } else {
 340                                         $this->coalescedQueues[$loc]['types'][] = $type;
 341                                 }
 342                         }
 343                 }
 344
 345                 return $this->coalescedQueues;
 346         }
 347
 348         /**
 349          * Execute any due periodic queue maintenance tasks for all queues.
 350          *
 351          * A task is "due" if the time ellapsed since the last run is greater than
 352          * the defined run period. Concurrent calls to this function will cause tasks
 353          * to be attempted twice, so they may need their own methods of mutual exclusion.
 354          *
 355          * @return int Number of tasks run
 356          */
 357         public function executeReadyPeriodicTasks() {
 358                 global $wgMemc;
 359
 360                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 361                 $key = wfForeignMemcKey( $db, $prefix, 'jobqueuegroup', 'taskruns', 'v1' );
 362                 $lastRuns = $wgMemc->get( $key ); // (queue => task => UNIX timestamp)
 363
 364                 $count = 0;
 365                 $tasksRun = array(); // (queue => task => UNIX timestamp)
 366                 foreach ( $this->getQueueTypes() as $type ) {
 367                         $queue = $this->get( $type );
 368                         foreach ( $queue->getPeriodicTasks() as $task => $definition ) {
 369                                 if ( $definition['period'] <= 0 ) {
 370                                         continue; // disabled
 371                                 } elseif ( !isset( $lastRuns[$type][$task] )
 372                                         || $lastRuns[$type][$task] < ( time() - $definition['period'] )
 373                                 ) {
 374                                         try {
 375                                                 if ( call_user_func( $definition['callback'] ) !== null ) {
 376                                                         $tasksRun[$type][$task] = time();
 377                                                         ++$count;
 378                                                 }
 379                                         } catch ( JobQueueError $e ) {
 380                                                 MWExceptionHandler::logException( $e );
 381                                         }
 382                                 }
 383                         }
 384                         // The tasks may have recycled jobs or release delayed jobs into the queue
 385                         if ( isset( $tasksRun[$type] ) && !$queue->isEmpty() ) {
 386                                 JobQueueAggregator::singleton()->notifyQueueNonEmpty( $this->wiki, $type );
 387                         }
 388                 }
 389
 390                 if ( $count === 0 ) {
 391                         return $count; // nothing to update
 392                 }
 393
 394                 $wgMemc->merge( $key, function ( $cache, $key, $lastRuns ) use ( $tasksRun ) {
 395                         if ( is_array( $lastRuns ) ) {
 396                                 foreach ( $tasksRun as $type => $tasks ) {
 397                                         foreach ( $tasks as $task => $timestamp ) {
 398                                                 if ( !isset( $lastRuns[$type][$task] )
 399                                                         || $timestamp > $lastRuns[$type][$task]
 400                                                 ) {
 401                                                         $lastRuns[$type][$task] = $timestamp;
 402                                                 }
 403                                         }
 404                                 }
 405                         } else {
 406                                 $lastRuns = $tasksRun;
 407                         }
 408
 409                         return $lastRuns;
 410                 } );
 411
 412                 return $count;
 413         }
 414
 415         /**
 416          * @param string $name
 417          * @return mixed
 418          */
 419         private function getCachedConfigVar( $name ) {
 420                 global $wgConf, $wgMemc;
 421
 422                 if ( $this->wiki === wfWikiID() ) {
 423                         return $GLOBALS[$name]; // common case
 424                 } else {
 425                         list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 426                         $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
 427                         $value = $wgMemc->get( $key ); // ('v' => ...) or false
 428                         if ( is_array( $value ) ) {
 429                                 return $value['v'];
 430                         } else {
 431                                 $value = $wgConf->getConfig( $this->wiki, $name );
 432                                 $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
 433
 434                                 return $value;
 435                         }
 436                 }
 437         }
 438 }