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