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  */
  22
  23 /**
  24  * Class to handle enqueueing of background jobs
  25  *
  26  * @ingroup JobQueue
  27  * @since 1.21
  28  */
  29 class JobQueueGroup {
  30         /** @var JobQueueGroup[] */
  31         protected static $instances = [];
  32
  33         /** @var ProcessCacheLRU */
  34         protected $cache;
  35
  36         /** @var string Wiki ID */
  37         protected $wiki;
  38         /** @var string|bool Read only rationale (or false if r/w) */
  39         protected $readOnlyReason;
  40
  41         /** @var array Map of (bucket => (queue => JobQueue, types => list of types) */
  42         protected $coalescedQueues;
  43
  44         /** @var Job[] */
  45         protected $bufferedJobs = [];
  46
  47         const TYPE_DEFAULT = 1; // integer; jobs popped by default
  48         const TYPE_ANY = 2; // integer; any job
  49
  50         const USE_CACHE = 1; // integer; use process or persistent cache
  51
  52         const PROC_CACHE_TTL = 15; // integer; seconds
  53
  54         const CACHE_VERSION = 1; // integer; cache version
  55
  56         /**
  57          * @param string $wiki Wiki ID
  58          * @param string|bool $readOnlyReason Read-only reason or false
  59          */
  60         protected function __construct( $wiki, $readOnlyReason ) {
  61                 $this->wiki = $wiki;
  62                 $this->readOnlyReason = $readOnlyReason;
  63                 $this->cache = new ProcessCacheLRU( 10 );
  64         }
  65
  66         /**
  67          * @param bool|string $wiki Wiki ID
  68          * @return JobQueueGroup
  69          */
  70         public static function singleton( $wiki = false ) {
  71                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  72                 if ( !isset( self::$instances[$wiki] ) ) {
  73                         self::$instances[$wiki] = new self( $wiki, wfConfiguredReadOnlyReason() );
  74                 }
  75
  76                 return self::$instances[$wiki];
  77         }
  78
  79         /**
  80          * Destroy the singleton instances
  81          *
  82          * @return void
  83          */
  84         public static function destroySingletons() {
  85                 self::$instances = [];
  86         }
  87
  88         /**
  89          * Get the job queue object for a given queue type
  90          *
  91          * @param string $type
  92          * @return JobQueue
  93          */
  94         public function get( $type ) {
  95                 global $wgJobTypeConf;
  96
  97                 $conf = [ 'wiki' => $this->wiki, 'type' => $type ];
  98                 if ( isset( $wgJobTypeConf[$type] ) ) {
  99                         $conf = $conf + $wgJobTypeConf[$type];
 100                 } else {
 101                         $conf = $conf + $wgJobTypeConf['default'];
 102                 }
 103                 $conf['aggregator'] = JobQueueAggregator::singleton();
 104                 if ( $this->readOnlyReason !== false ) {
 105                         $conf['readOnlyReason'] = $this->readOnlyReason;
 106                 }
 107
 108                 return JobQueue::factory( $conf );
 109         }
 110
 111         /**
 112          * Insert jobs into the respective queues of which they belong
 113          *
 114          * This inserts the jobs into the queue specified by $wgJobTypeConf
 115          * and updates the aggregate job queue information cache as needed.
 116          *
 117          * @param IJobSpecification|IJobSpecification[] $jobs A single Job or a list of Jobs
 118          * @throws InvalidArgumentException
 119          * @return void
 120          */
 121         public function push( $jobs ) {
 122                 global $wgJobTypesExcludedFromDefaultQueue;
 123
 124                 $jobs = is_array( $jobs ) ? $jobs : [ $jobs ];
 125                 if ( !count( $jobs ) ) {
 126                         return;
 127                 }
 128
 129                 $this->assertValidJobs( $jobs );
 130
 131                 $jobsByType = []; // (job type => list of jobs)
 132                 foreach ( $jobs as $job ) {
 133                         $jobsByType[$job->getType()][] = $job;
 134                 }
 135
 136                 foreach ( $jobsByType as $type => $jobs ) {
 137                         $this->get( $type )->push( $jobs );
 138                 }
 139
 140                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 141                         $list = $this->cache->get( 'queues-ready', 'list' );
 142                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 143                                 $this->cache->clear( 'queues-ready' );
 144                         }
 145                 }
 146
 147                 $cache = ObjectCache::getLocalClusterInstance();
 148                 $cache->set(
 149                         $cache->makeGlobalKey( 'jobqueue', $this->wiki, 'hasjobs', self::TYPE_ANY ),
 150                         'true',
 151                         15
 152                 );
 153                 if ( array_diff( array_keys( $jobsByType ), $wgJobTypesExcludedFromDefaultQueue ) ) {
 154                         $cache->set(
 155                                 $cache->makeGlobalKey( 'jobqueue', $this->wiki, 'hasjobs', self::TYPE_DEFAULT ),
 156                                 'true',
 157                                 15
 158                         );
 159                 }
 160         }
 161
 162         /**
 163          * Buffer jobs for insertion via push() or call it now if in CLI mode
 164          *
 165          * Note that pushLazyJobs() is registered as a deferred update just before
 166          * DeferredUpdates::doUpdates() in MediaWiki and JobRunner classes in order
 167          * to be executed as the very last deferred update (T100085, T154425).
 168          *
 169          * @param IJobSpecification|IJobSpecification[] $jobs A single Job or a list of Jobs
 170          * @return void
 171          * @since 1.26
 172          */
 173         public function lazyPush( $jobs ) {
 174                 if ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' ) {
 175                         $this->push( $jobs );
 176                         return;
 177                 }
 178
 179                 $jobs = is_array( $jobs ) ? $jobs : [ $jobs ];
 180
 181                 // Throw errors now instead of on push(), when other jobs may be buffered
 182                 $this->assertValidJobs( $jobs );
 183
 184                 $this->bufferedJobs = array_merge( $this->bufferedJobs, $jobs );
 185         }
 186
 187         /**
 188          * Push all jobs buffered via lazyPush() into their respective queues
 189          *
 190          * @return void
 191          * @since 1.26
 192          */
 193         public static function pushLazyJobs() {
 194                 foreach ( self::$instances as $group ) {
 195                         try {
 196                                 $group->push( $group->bufferedJobs );
 197                                 $group->bufferedJobs = [];
 198                         } catch ( Exception $e ) {
 199                                 // Get in as many jobs as possible and let other post-send updates happen
 200                                 MWExceptionHandler::logException( $e );
 201                         }
 202                 }
 203         }
 204
 205         /**
 206          * Pop a job off one of the job queues
 207          *
 208          * This pops a job off a queue as specified by $wgJobTypeConf and
 209          * updates the aggregate job queue information cache as needed.
 210          *
 211          * @param int|string $qtype JobQueueGroup::TYPE_* constant or job type string
 212          * @param int $flags Bitfield of JobQueueGroup::USE_* constants
 213          * @param array $blacklist List of job types to ignore
 214          * @return Job|bool Returns false on failure
 215          */
 216         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0, array $blacklist = [] ) {
 217                 $job = false;
 218
 219                 if ( is_string( $qtype ) ) { // specific job type
 220                         if ( !in_array( $qtype, $blacklist ) ) {
 221                                 $job = $this->get( $qtype )->pop();
 222                         }
 223                 } else { // any job in the "default" jobs types
 224                         if ( $flags & self::USE_CACHE ) {
 225                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 226                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 227                                 }
 228                                 $types = $this->cache->get( 'queues-ready', 'list' );
 229                         } else {
 230                                 $types = $this->getQueuesWithJobs();
 231                         }
 232
 233                         if ( $qtype == self::TYPE_DEFAULT ) {
 234                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 235                         }
 236
 237                         $types = array_diff( $types, $blacklist ); // avoid selected types
 238                         shuffle( $types ); // avoid starvation
 239
 240                         foreach ( $types as $type ) { // for each queue...
 241                                 $job = $this->get( $type )->pop();
 242                                 if ( $job ) { // found
 243                                         break;
 244                                 } else { // not found
 245                                         $this->cache->clear( 'queues-ready' );
 246                                 }
 247                         }
 248                 }
 249
 250                 return $job;
 251         }
 252
 253         /**
 254          * Acknowledge that a job was completed
 255          *
 256          * @param Job $job
 257          * @return void
 258          */
 259         public function ack( Job $job ) {
 260                 $this->get( $job->getType() )->ack( $job );
 261         }
 262
 263         /**
 264          * Register the "root job" of a given job into the queue for de-duplication.
 265          * This should only be called right *after* all the new jobs have been inserted.
 266          *
 267          * @param Job $job
 268          * @return bool
 269          */
 270         public function deduplicateRootJob( Job $job ) {
 271                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 272         }
 273
 274         /**
 275          * Wait for any replica DBs or backup queue servers to catch up.
 276          *
 277          * This does nothing for certain queue classes.
 278          *
 279          * @return void
 280          */
 281         public function waitForBackups() {
 282                 global $wgJobTypeConf;
 283
 284                 // Try to avoid doing this more than once per queue storage medium
 285                 foreach ( $wgJobTypeConf as $type => $conf ) {
 286                         $this->get( $type )->waitForBackups();
 287                 }
 288         }
 289
 290         /**
 291          * Get the list of queue types
 292          *
 293          * @return array List of strings
 294          */
 295         public function getQueueTypes() {
 296                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 297         }
 298
 299         /**
 300          * Get the list of default queue types
 301          *
 302          * @return array List of strings
 303          */
 304         public function getDefaultQueueTypes() {
 305                 global $wgJobTypesExcludedFromDefaultQueue;
 306
 307                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 308         }
 309
 310         /**
 311          * Check if there are any queues with jobs (this is cached)
 312          *
 313          * @param int $type JobQueueGroup::TYPE_* constant
 314          * @return bool
 315          * @since 1.23
 316          */
 317         public function queuesHaveJobs( $type = self::TYPE_ANY ) {
 318                 $cache = ObjectCache::getLocalClusterInstance();
 319                 $key = $cache->makeGlobalKey( 'jobqueue', $this->wiki, 'hasjobs', $type );
 320
 321                 $value = $cache->get( $key );
 322                 if ( $value === false ) {
 323                         $queues = $this->getQueuesWithJobs();
 324                         if ( $type == self::TYPE_DEFAULT ) {
 325                                 $queues = array_intersect( $queues, $this->getDefaultQueueTypes() );
 326                         }
 327                         $value = count( $queues ) ? 'true' : 'false';
 328                         $cache->add( $key, $value, 15 );
 329                 }
 330
 331                 return ( $value === 'true' );
 332         }
 333
 334         /**
 335          * Get the list of job types that have non-empty queues
 336          *
 337          * @return array List of job types that have non-empty queues
 338          */
 339         public function getQueuesWithJobs() {
 340                 $types = [];
 341                 foreach ( $this->getCoalescedQueues() as $info ) {
 342                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 343                         if ( is_array( $nonEmpty ) ) { // batching features supported
 344                                 $types = array_merge( $types, $nonEmpty );
 345                         } else { // we have to go through the queues in the bucket one-by-one
 346                                 foreach ( $info['types'] as $type ) {
 347                                         if ( !$this->get( $type )->isEmpty() ) {
 348                                                 $types[] = $type;
 349                                         }
 350                                 }
 351                         }
 352                 }
 353
 354                 return $types;
 355         }
 356
 357         /**
 358          * Get the size of the queus for a list of job types
 359          *
 360          * @return array Map of (job type => size)
 361          */
 362         public function getQueueSizes() {
 363                 $sizeMap = [];
 364                 foreach ( $this->getCoalescedQueues() as $info ) {
 365                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 366                         if ( is_array( $sizes ) ) { // batching features supported
 367                                 $sizeMap = $sizeMap + $sizes;
 368                         } else { // we have to go through the queues in the bucket one-by-one
 369                                 foreach ( $info['types'] as $type ) {
 370                                         $sizeMap[$type] = $this->get( $type )->getSize();
 371                                 }
 372                         }
 373                 }
 374
 375                 return $sizeMap;
 376         }
 377
 378         /**
 379          * @return array
 380          */
 381         protected function getCoalescedQueues() {
 382                 global $wgJobTypeConf;
 383
 384                 if ( $this->coalescedQueues === null ) {
 385                         $this->coalescedQueues = [];
 386                         foreach ( $wgJobTypeConf as $type => $conf ) {
 387                                 $queue = JobQueue::factory(
 388                                         [ 'wiki' => $this->wiki, 'type' => 'null' ] + $conf );
 389                                 $loc = $queue->getCoalesceLocationInternal();
 390                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 391                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 392                                         $this->coalescedQueues[$loc]['types'] = [];
 393                                 }
 394                                 if ( $type === 'default' ) {
 395                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 396                                                 $this->coalescedQueues[$loc]['types'],
 397                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 398                                         );
 399                                 } else {
 400                                         $this->coalescedQueues[$loc]['types'][] = $type;
 401                                 }
 402                         }
 403                 }
 404
 405                 return $this->coalescedQueues;
 406         }
 407
 408         /**
 409          * @param string $name
 410          * @return mixed
 411          */
 412         private function getCachedConfigVar( $name ) {
 413                 // @TODO: cleanup this whole method with a proper config system
 414                 if ( $this->wiki === wfWikiID() ) {
 415                         return $GLOBALS[$name]; // common case
 416                 } else {
 417                         $wiki = $this->wiki;
 418                         $cache = ObjectCache::getMainWANInstance();
 419                         $value = $cache->getWithSetCallback(
 420                                 $cache->makeGlobalKey( 'jobqueue', 'configvalue', $wiki, $name ),
 421                                 $cache::TTL_DAY + mt_rand( 0, $cache::TTL_DAY ),
 422                                 function () use ( $wiki, $name ) {
 423                                         global $wgConf;
 424
 425                                         return [ 'v' => $wgConf->getConfig( $wiki, $name ) ];
 426                                 },
 427                                 [ 'pcTTL' => WANObjectCache::TTL_PROC_LONG ]
 428                         );
 429
 430                         return $value['v'];
 431                 }
 432         }
 433
 434         /**
 435          * @param array $jobs
 436          * @throws InvalidArgumentException
 437          */
 438         private function assertValidJobs( array $jobs ) {
 439                 foreach ( $jobs as $job ) { // sanity checks
 440                         if ( !( $job instanceof IJobSpecification ) ) {
 441                                 throw new InvalidArgumentException( "Expected IJobSpecification objects" );
 442                         }
 443                 }
 444         }
 445
 446         function __destruct() {
 447                 $n = count( $this->bufferedJobs );
 448                 if ( $n > 0 ) {
 449                         $type = implode( ', ', array_unique( array_map( 'get_class', $this->bufferedJobs ) ) );
 450                         trigger_error( __METHOD__ . ": $n buffered job(s) of type(s) $type never inserted." );
 451                 }
 452         }
 453 }