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 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         /** @var Job[] */
  44         protected $bufferedJobs = array();
  45
  46         const TYPE_DEFAULT = 1; // integer; jobs popped by default
  47         const TYPE_ANY = 2; // integer; any job
  48
  49         const USE_CACHE = 1; // integer; use process or persistent cache
  50
  51         const PROC_CACHE_TTL = 15; // integer; seconds
  52
  53         const CACHE_VERSION = 1; // integer; cache version
  54
  55         /**
  56          * @param string $wiki Wiki ID
  57          */
  58         protected function __construct( $wiki ) {
  59                 $this->wiki = $wiki;
  60                 $this->cache = new ProcessCacheLRU( 10 );
  61         }
  62
  63         /**
  64          * @param bool|string $wiki Wiki ID
  65          * @return JobQueueGroup
  66          */
  67         public static function singleton( $wiki = false ) {
  68                 $wiki = ( $wiki === false ) ? wfWikiID() : $wiki;
  69                 if ( !isset( self::$instances[$wiki] ) ) {
  70                         self::$instances[$wiki] = new self( $wiki );
  71                 }
  72
  73                 return self::$instances[$wiki];
  74         }
  75
  76         /**
  77          * Destroy the singleton instances
  78          *
  79          * @return void
  80          */
  81         public static function destroySingletons() {
  82                 self::$instances = array();
  83         }
  84
  85         /**
  86          * Get the job queue object for a given queue type
  87          *
  88          * @param string $type
  89          * @return JobQueue
  90          */
  91         public function get( $type ) {
  92                 global $wgJobTypeConf;
  93
  94                 $conf = array( 'wiki' => $this->wiki, 'type' => $type );
  95                 if ( isset( $wgJobTypeConf[$type] ) ) {
  96                         $conf = $conf + $wgJobTypeConf[$type];
  97                 } else {
  98                         $conf = $conf + $wgJobTypeConf['default'];
  99                 }
 100                 $conf['aggregator'] = JobQueueAggregator::singleton();
 101
 102                 return JobQueue::factory( $conf );
 103         }
 104
 105         /**
 106          * Insert jobs into the respective queues of which they belong
 107          *
 108          * This inserts the jobs into the queue specified by $wgJobTypeConf
 109          * and updates the aggregate job queue information cache as needed.
 110          *
 111          * @param IJobSpecification|IJobSpecification[] $jobs A single Job or a list of Jobs
 112          * @throws InvalidArgumentException
 113          * @return void
 114          */
 115         public function push( $jobs ) {
 116                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 117                 if ( !count( $jobs ) ) {
 118                         return;
 119                 }
 120
 121                 $this->assertValidJobs( $jobs );
 122
 123                 $jobsByType = array(); // (job type => list of jobs)
 124                 foreach ( $jobs as $job ) {
 125                         $jobsByType[$job->getType()][] = $job;
 126                 }
 127
 128                 foreach ( $jobsByType as $type => $jobs ) {
 129                         $this->get( $type )->push( $jobs );
 130                 }
 131
 132                 if ( $this->cache->has( 'queues-ready', 'list' ) ) {
 133                         $list = $this->cache->get( 'queues-ready', 'list' );
 134                         if ( count( array_diff( array_keys( $jobsByType ), $list ) ) ) {
 135                                 $this->cache->clear( 'queues-ready' );
 136                         }
 137                 }
 138         }
 139
 140         /**
 141          * Buffer jobs for insertion via push() or call it now if in CLI mode
 142          *
 143          * Note that MediaWiki::restInPeace() calls pushLazyJobs()
 144          *
 145          * @param IJobSpecification|IJobSpecification[] $jobs A single Job or a list of Jobs
 146          * @return void
 147          * @since 1.26
 148          */
 149         public function lazyPush( $jobs ) {
 150                 if ( PHP_SAPI === 'cli' ) {
 151                         $this->push( $jobs );
 152                         return;
 153                 }
 154
 155                 $jobs = is_array( $jobs ) ? $jobs : array( $jobs );
 156
 157                 // Throw errors now instead of on push(), when other jobs may be buffered
 158                 $this->assertValidJobs( $jobs );
 159
 160                 $this->bufferedJobs = array_merge( $this->bufferedJobs, $jobs );
 161         }
 162
 163         /**
 164          * Push all jobs buffered via lazyPush() into their respective queues
 165          *
 166          * @return void
 167          * @since 1.26
 168          */
 169         public function pushLazyJobs() {
 170                 $this->push( $this->bufferedJobs );
 171
 172                 $this->bufferedJobs = array();
 173         }
 174
 175         /**
 176          * Pop a job off one of the job queues
 177          *
 178          * This pops a job off a queue as specified by $wgJobTypeConf and
 179          * updates the aggregate job queue information cache as needed.
 180          *
 181          * @param int|string $qtype JobQueueGroup::TYPE_* constant or job type string
 182          * @param int $flags Bitfield of JobQueueGroup::USE_* constants
 183          * @param array $blacklist List of job types to ignore
 184          * @return Job|bool Returns false on failure
 185          */
 186         public function pop( $qtype = self::TYPE_DEFAULT, $flags = 0, array $blacklist = array() ) {
 187                 $job = false;
 188
 189                 if ( is_string( $qtype ) ) { // specific job type
 190                         if ( !in_array( $qtype, $blacklist ) ) {
 191                                 $job = $this->get( $qtype )->pop();
 192                         }
 193                 } else { // any job in the "default" jobs types
 194                         if ( $flags & self::USE_CACHE ) {
 195                                 if ( !$this->cache->has( 'queues-ready', 'list', self::PROC_CACHE_TTL ) ) {
 196                                         $this->cache->set( 'queues-ready', 'list', $this->getQueuesWithJobs() );
 197                                 }
 198                                 $types = $this->cache->get( 'queues-ready', 'list' );
 199                         } else {
 200                                 $types = $this->getQueuesWithJobs();
 201                         }
 202
 203                         if ( $qtype == self::TYPE_DEFAULT ) {
 204                                 $types = array_intersect( $types, $this->getDefaultQueueTypes() );
 205                         }
 206
 207                         $types = array_diff( $types, $blacklist ); // avoid selected types
 208                         shuffle( $types ); // avoid starvation
 209
 210                         foreach ( $types as $type ) { // for each queue...
 211                                 $job = $this->get( $type )->pop();
 212                                 if ( $job ) { // found
 213                                         break;
 214                                 } else { // not found
 215                                         $this->cache->clear( 'queues-ready' );
 216                                 }
 217                         }
 218                 }
 219
 220                 return $job;
 221         }
 222
 223         /**
 224          * Acknowledge that a job was completed
 225          *
 226          * @param Job $job
 227          * @return void
 228          */
 229         public function ack( Job $job ) {
 230                 $this->get( $job->getType() )->ack( $job );
 231         }
 232
 233         /**
 234          * Register the "root job" of a given job into the queue for de-duplication.
 235          * This should only be called right *after* all the new jobs have been inserted.
 236          *
 237          * @param Job $job
 238          * @return bool
 239          */
 240         public function deduplicateRootJob( Job $job ) {
 241                 return $this->get( $job->getType() )->deduplicateRootJob( $job );
 242         }
 243
 244         /**
 245          * Wait for any slaves or backup queue servers to catch up.
 246          *
 247          * This does nothing for certain queue classes.
 248          *
 249          * @return void
 250          */
 251         public function waitForBackups() {
 252                 global $wgJobTypeConf;
 253
 254                 // Try to avoid doing this more than once per queue storage medium
 255                 foreach ( $wgJobTypeConf as $type => $conf ) {
 256                         $this->get( $type )->waitForBackups();
 257                 }
 258         }
 259
 260         /**
 261          * Get the list of queue types
 262          *
 263          * @return array List of strings
 264          */
 265         public function getQueueTypes() {
 266                 return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
 267         }
 268
 269         /**
 270          * Get the list of default queue types
 271          *
 272          * @return array List of strings
 273          */
 274         public function getDefaultQueueTypes() {
 275                 global $wgJobTypesExcludedFromDefaultQueue;
 276
 277                 return array_diff( $this->getQueueTypes(), $wgJobTypesExcludedFromDefaultQueue );
 278         }
 279
 280         /**
 281          * Check if there are any queues with jobs (this is cached)
 282          *
 283          * @param int $type JobQueueGroup::TYPE_* constant
 284          * @return bool
 285          * @since 1.23
 286          */
 287         public function queuesHaveJobs( $type = self::TYPE_ANY ) {
 288                 global $wgMemc;
 289
 290                 $key = wfMemcKey( 'jobqueue', 'queueshavejobs', $type );
 291
 292                 $value = $wgMemc->get( $key );
 293                 if ( $value === false ) {
 294                         $queues = $this->getQueuesWithJobs();
 295                         if ( $type == self::TYPE_DEFAULT ) {
 296                                 $queues = array_intersect( $queues, $this->getDefaultQueueTypes() );
 297                         }
 298                         $value = count( $queues ) ? 'true' : 'false';
 299                         $wgMemc->add( $key, $value, 15 );
 300                 }
 301
 302                 return ( $value === 'true' );
 303         }
 304
 305         /**
 306          * Get the list of job types that have non-empty queues
 307          *
 308          * @return array List of job types that have non-empty queues
 309          */
 310         public function getQueuesWithJobs() {
 311                 $types = array();
 312                 foreach ( $this->getCoalescedQueues() as $info ) {
 313                         $nonEmpty = $info['queue']->getSiblingQueuesWithJobs( $this->getQueueTypes() );
 314                         if ( is_array( $nonEmpty ) ) { // batching features supported
 315                                 $types = array_merge( $types, $nonEmpty );
 316                         } else { // we have to go through the queues in the bucket one-by-one
 317                                 foreach ( $info['types'] as $type ) {
 318                                         if ( !$this->get( $type )->isEmpty() ) {
 319                                                 $types[] = $type;
 320                                         }
 321                                 }
 322                         }
 323                 }
 324
 325                 return $types;
 326         }
 327
 328         /**
 329          * Get the size of the queus for a list of job types
 330          *
 331          * @return array Map of (job type => size)
 332          */
 333         public function getQueueSizes() {
 334                 $sizeMap = array();
 335                 foreach ( $this->getCoalescedQueues() as $info ) {
 336                         $sizes = $info['queue']->getSiblingQueueSizes( $this->getQueueTypes() );
 337                         if ( is_array( $sizes ) ) { // batching features supported
 338                                 $sizeMap = $sizeMap + $sizes;
 339                         } else { // we have to go through the queues in the bucket one-by-one
 340                                 foreach ( $info['types'] as $type ) {
 341                                         $sizeMap[$type] = $this->get( $type )->getSize();
 342                                 }
 343                         }
 344                 }
 345
 346                 return $sizeMap;
 347         }
 348
 349         /**
 350          * @return array
 351          */
 352         protected function getCoalescedQueues() {
 353                 global $wgJobTypeConf;
 354
 355                 if ( $this->coalescedQueues === null ) {
 356                         $this->coalescedQueues = array();
 357                         foreach ( $wgJobTypeConf as $type => $conf ) {
 358                                 $queue = JobQueue::factory(
 359                                         array( 'wiki' => $this->wiki, 'type' => 'null' ) + $conf );
 360                                 $loc = $queue->getCoalesceLocationInternal();
 361                                 if ( !isset( $this->coalescedQueues[$loc] ) ) {
 362                                         $this->coalescedQueues[$loc]['queue'] = $queue;
 363                                         $this->coalescedQueues[$loc]['types'] = array();
 364                                 }
 365                                 if ( $type === 'default' ) {
 366                                         $this->coalescedQueues[$loc]['types'] = array_merge(
 367                                                 $this->coalescedQueues[$loc]['types'],
 368                                                 array_diff( $this->getQueueTypes(), array_keys( $wgJobTypeConf ) )
 369                                         );
 370                                 } else {
 371                                         $this->coalescedQueues[$loc]['types'][] = $type;
 372                                 }
 373                         }
 374                 }
 375
 376                 return $this->coalescedQueues;
 377         }
 378
 379         /**
 380          * @param string $name
 381          * @return mixed
 382          */
 383         private function getCachedConfigVar( $name ) {
 384                 global $wgConf, $wgMemc;
 385
 386                 if ( $this->wiki === wfWikiID() ) {
 387                         return $GLOBALS[$name]; // common case
 388                 } else {
 389                         list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 390                         $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
 391                         $value = $wgMemc->get( $key ); // ('v' => ...) or false
 392                         if ( is_array( $value ) ) {
 393                                 return $value['v'];
 394                         } else {
 395                                 $value = $wgConf->getConfig( $this->wiki, $name );
 396                                 $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
 397
 398                                 return $value;
 399                         }
 400                 }
 401         }
 402
 403         /**
 404          * @param array $jobs
 405          * @throws InvalidArgumentException
 406          */
 407         private function assertValidJobs( array $jobs ) {
 408                 foreach ( $jobs as $job ) { // sanity checks
 409                         if ( !( $job instanceof IJobSpecification ) ) {
 410                                 throw new InvalidArgumentException( "Expected IJobSpecification objects" );
 411                         }
 412                 }
 413         }
 414
 415         function __destruct() {
 416                 $n = count( $this->bufferedJobs );
 417                 if ( $n > 0 ) {
 418                         trigger_error( __METHOD__ . ": $n buffered job(s) never inserted." );
 419                         $this->pushLazyJobs(); // try to do it now
 420                 }
 421         }
 422 }