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