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