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
 147         /**
 148          * Buffer jobs for insertion via push() or call it now if in CLI mode
 149          *
 150          * Note that MediaWiki::restInPeace() calls pushLazyJobs()
 151          *
 152          * @param IJobSpecification|IJobSpecification[] $jobs A single Job or a list of Jobs
 153          * @return void
 154          * @since 1.26
 155          */
 156         public function lazyPush( $jobs ) {
 157                 if ( PHP_SAPI === 'cli' ) {
 158                         $this->push( $jobs );
 159                         return;
 160                 }
 161
 162                 $jobs = is_array( $jobs ) ? $jobs : [ $jobs ];
 163
 164                 // Throw errors now instead of on push(), when other jobs may be buffered
 165                 $this->assertValidJobs( $jobs );
 166
 167                 $this->bufferedJobs = array_merge( $this->bufferedJobs, $jobs );
 168         }
 169
 170         /**
 171          * Push all jobs buffered via lazyPush() into their respective queues
 172          *
 173          * @return void
 174          * @since 1.26
 175          */
 176         public static function pushLazyJobs() {
 177                 foreach ( self::$instances as $group ) {
 178                         $group->push( $group->bufferedJobs );
 179                         $group->bufferedJobs = [];
 180                 }
 181         }
 182
 183         /**
 184          * Pop a job off one of the job queues
 185          *
 186          * This pops a job off a queue as specified by $wgJobTypeConf and
 187          * updates the aggregate job queue information cache as needed.
 188          *
 189          * @param int|string $qtype JobQueueGroup::TYPE_* constant or job type string
 190          * @param int $flags Bitfield of JobQueueGroup::USE_* constants
 191          * @param array $blacklist List of job types to ignore
 192          * @return Job|bool Returns false on failure
 193          */
 194         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0, array $blacklist = [] ) {
 195                 $job = false;
 196
 197                 if ( is_string( $qtype ) ) { // specific job type
 198                         if ( !in_array( $qtype, $blacklist ) ) {
 199                                 $job = $this->get( $qtype )->pop();
 200                         }
 201                 } else { // any job in the "default" jobs types
 202                         if ( $flags & self::USE_CACHE ) {
 203                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 204                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 205                                 }
 206                                 $types = $this->cache->get( 'queues-ready', 'list' );
 207                         } else {
 208                                 $types = $this->getQueuesWithJobs();
 209                         }
 210
 211                         if ( $qtype == self::TYPE_DEFAULT ) {
 212                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 213                         }
 214
 215                         $types = array_diff( $types, $blacklist ); // avoid selected types
 216                         shuffle( $types ); // avoid starvation
 217
 218                         foreach ( $types as $type ) { // for each queue...
 219                                 $job = $this->get( $type )->pop();
 220                                 if ( $job ) { // found
 221                                         break;
 222                                 } else { // not found
 223                                         $this->cache->clear( 'queues-ready' );
 224                                 }
 225                         }
 226                 }
 227
 228                 return $job;
 229         }
 230
 231         /**
 232          * Acknowledge that a job was completed
 233          *
 234          * @param Job $job
 235          * @return void
 236          */
 237         public function ack( Job $job ) {
 238                 $this->get( $job->getType() )->ack( $job );
 239         }
 240
 241         /**
 242          * Register the "root job" of a given job into the queue for de-duplication.
 243          * This should only be called right *after* all the new jobs have been inserted.
 244          *
 245          * @param Job $job
 246          * @return bool
 247          */
 248         public function deduplicateRootJob( Job $job ) {
 249                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 250         }
 251
 252         /**
 253          * Wait for any slaves or backup queue servers to catch up.
 254          *
 255          * This does nothing for certain queue classes.
 256          *
 257          * @return void
 258          */
 259         public function waitForBackups() {
 260                 global $wgJobTypeConf;
 261
 262                 // Try to avoid doing this more than once per queue storage medium
 263                 foreach ( $wgJobTypeConf as $type => $conf ) {
 264                         $this->get( $type )->waitForBackups();
 265                 }
 266         }
 267
 268         /**
 269          * Get the list of queue types
 270          *
 271          * @return array List of strings
 272          */
 273         public function getQueueTypes() {
 274                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 275         }
 276
 277         /**
 278          * Get the list of default queue types
 279          *
 280          * @return array List of strings
 281          */
 282         public function getDefaultQueueTypes() {
 283                 global $wgJobTypesExcludedFromDefaultQueue;
 284
 285                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 286         }
 287
 288         /**
 289          * Check if there are any queues with jobs (this is cached)
 290          *
 291          * @param int $type JobQueueGroup::TYPE_* constant
 292          * @return bool
 293          * @since 1.23
 294          */
 295         public function queuesHaveJobs( $type = self::TYPE_ANY ) {
 296                 $key = wfMemcKey( 'jobqueue', 'queueshavejobs', $type );
 297                 $cache = ObjectCache::getLocalClusterInstance();
 298
 299                 $value = $cache->get( $key );
 300                 if ( $value === false ) {
 301                         $queues = $this->getQueuesWithJobs();
 302                         if ( $type == self::TYPE_DEFAULT ) {
 303                                 $queues = array_intersect( $queues, $this->getDefaultQueueTypes() );
 304                         }
 305                         $value = count( $queues ) ? 'true' : 'false';
 306                         $cache->add( $key, $value, 15 );
 307                 }
 308
 309                 return ( $value === 'true' );
 310         }
 311
 312         /**
 313          * Get the list of job types that have non-empty queues
 314          *
 315          * @return array List of job types that have non-empty queues
 316          */
 317         public function getQueuesWithJobs() {
 318                 $types = [];
 319                 foreach ( $this->getCoalescedQueues() as $info ) {
 320                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 321                         if ( is_array( $nonEmpty ) ) { // batching features supported
 322                                 $types = array_merge( $types, $nonEmpty );
 323                         } else { // we have to go through the queues in the bucket one-by-one
 324                                 foreach ( $info['types'] as $type ) {
 325                                         if ( !$this->get( $type )->isEmpty() ) {
 326                                                 $types[] = $type;
 327                                         }
 328                                 }
 329                         }
 330                 }
 331
 332                 return $types;
 333         }
 334
 335         /**
 336          * Get the size of the queus for a list of job types
 337          *
 338          * @return array Map of (job type => size)
 339          */
 340         public function getQueueSizes() {
 341                 $sizeMap = [];
 342                 foreach ( $this->getCoalescedQueues() as $info ) {
 343                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 344                         if ( is_array( $sizes ) ) { // batching features supported
 345                                 $sizeMap = $sizeMap + $sizes;
 346                         } else { // we have to go through the queues in the bucket one-by-one
 347                                 foreach ( $info['types'] as $type ) {
 348                                         $sizeMap[$type] = $this->get( $type )->getSize();
 349                                 }
 350                         }
 351                 }
 352
 353                 return $sizeMap;
 354         }
 355
 356         /**
 357          * @return array
 358          */
 359         protected function getCoalescedQueues() {
 360                 global $wgJobTypeConf;
 361
 362                 if ( $this->coalescedQueues === null ) {
 363                         $this->coalescedQueues = [];
 364                         foreach ( $wgJobTypeConf as $type => $conf ) {
 365                                 $queue = JobQueue::factory(
 366                                         [ 'wiki' => $this->wiki, 'type' => 'null' ] + $conf );
 367                                 $loc = $queue->getCoalesceLocationInternal();
 368                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 369                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 370                                         $this->coalescedQueues[$loc]['types'] = [];
 371                                 }
 372                                 if ( $type === 'default' ) {
 373                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 374                                                 $this->coalescedQueues[$loc]['types'],
 375                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 376                                         );
 377                                 } else {
 378                                         $this->coalescedQueues[$loc]['types'][] = $type;
 379                                 }
 380                         }
 381                 }
 382
 383                 return $this->coalescedQueues;
 384         }
 385
 386         /**
 387          * @param string $name
 388          * @return mixed
 389          */
 390         private function getCachedConfigVar( $name ) {
 391                 // @TODO: cleanup this whole method with a proper config system
 392                 if ( $this->wiki === wfWikiID() ) {
 393                         return $GLOBALS[$name]; // common case
 394                 } else {
 395                         $wiki = $this->wiki;
 396                         $cache = ObjectCache::getMainWANInstance();
 397                         $value = $cache->getWithSetCallback(
 398                                 $cache->makeGlobalKey( 'jobqueue', 'configvalue', $wiki, $name ),
 399                                 $cache::TTL_DAY + mt_rand( 0, $cache::TTL_DAY ),
 400                                 function () use ( $wiki, $name ) {
 401                                         global $wgConf;
 402
 403                                         return [ 'v' => $wgConf->getConfig( $wiki, $name ) ];
 404                                 },
 405                                 [ 'pcTTL' => 30 ]
 406                         );
 407
 408                         return $value['v'];
 409                 }
 410         }
 411
 412         /**
 413          * @param array $jobs
 414          * @throws InvalidArgumentException
 415          */
 416         private function assertValidJobs( array $jobs ) {
 417                 foreach ( $jobs as $job ) { // sanity checks
 418                         if ( !( $job instanceof IJobSpecification ) ) {
 419                                 throw new InvalidArgumentException( "Expected IJobSpecification objects" );
 420                         }
 421                 }
 422         }
 423
 424         function __destruct() {
 425                 $n = count( $this->bufferedJobs );
 426                 if ( $n > 0 ) {
 427                         $type = implode( ', ', array_unique( array_map( 'get_class', $this->bufferedJobs ) ) );
 428                         trigger_error( __METHOD__ . ": $n buffered job(s) of type(s) $type never inserted." );
 429                 }
 430         }
 431 }