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