includes/jobqueue/JobQueueRedis.php

   1 <?php
   2 /**
   3  * Redis-backed job queue 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 job queues stored in Redis
  26  *
  27  * This is a faster and less resource-intensive job queue than JobQueueDB.
  28  * All data for a queue using this class is placed into one redis server.
  29  *
  30  * There are eight main redis keys used to track jobs:
  31  *   - l-unclaimed  : A list of job IDs used for ready unclaimed jobs
  32  *   - z-claimed    : A sorted set of (job ID, UNIX timestamp as score) used for job retries
  33  *   - z-abandoned  : A sorted set of (job ID, UNIX timestamp as score) used for broken jobs
  34  *   - z-delayed    : A sorted set of (job ID, UNIX timestamp as score) used for delayed jobs
  35  *   - h-idBySha1   : A hash of (SHA1 => job ID) for unclaimed jobs used for de-duplication
  36  *   - h-sha1ById   : A hash of (job ID => SHA1) for unclaimed jobs used for de-duplication
  37  *   - h-attempts   : A hash of (job ID => attempt count) used for job claiming/retries
  38  *   - h-data       : A hash of (job ID => serialized blobs) for job storage
  39  * A job ID can be in only one of z-delayed, l-unclaimed, z-claimed, and z-abandoned.
  40  * If an ID appears in any of those lists, it should have a h-data entry for its ID.
  41  * If a job has a SHA1 de-duplication value and its ID is in l-unclaimed or z-delayed, then
  42  * there should be no other such jobs with that SHA1. Every h-idBySha1 entry has an h-sha1ById
  43  * entry and every h-sha1ById must refer to an ID that is l-unclaimed. If a job has its
  44  * ID in z-claimed or z-abandoned, then it must also have an h-attempts entry for its ID.
  45  *
  46  * Additionally, "rootjob:* keys track "root jobs" used for additional de-duplication.
  47  * Aside from root job keys, all keys have no expiry, and are only removed when jobs are run.
  48  * All the keys are prefixed with the relevant wiki ID information.
  49  *
  50  * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic operations.
  51  * Additionally, it should be noted that redis has different persistence modes, such
  52  * as rdb snapshots, journaling, and no persistence. Appropriate configuration should be
  53  * made on the servers based on what queues are using it and what tolerance they have.
  54  *
  55  * @ingroup JobQueue
  56  * @ingroup Redis
  57  * @since 1.22
  58  */
  59 class JobQueueRedis extends JobQueue {
  60         /** @var RedisConnectionPool */
  61         protected $redisPool;
  62
  63         /** @var string Server address */
  64         protected $server;
  65         /** @var string Compression method to use */
  66         protected $compression;
  67
  68         const MAX_AGE_PRUNE = 604800; // integer; seconds a job can live once claimed (7 days)
  69
  70         /** @var string Key to prefix the queue keys with (used for testing) */
  71         protected $key;
  72
  73         /**
  74          * @param array $params Possible keys:
  75          *   - redisConfig : An array of parameters to RedisConnectionPool::__construct().
  76          *                   Note that the serializer option is ignored as "none" is always used.
  77          *   - redisServer : A hostname/port combination or the absolute path of a UNIX socket.
  78          *                   If a hostname is specified but no port, the standard port number
  79          *                   6379 will be used. Required.
  80          *   - compression : The type of compression to use; one of (none,gzip).
  81          *   - daemonized  : Set to true if the redisJobRunnerService runs in the background.
  82          *                   This will disable job recycling/undelaying from the MediaWiki side
  83          *                   to avoid redundance and out-of-sync configuration.
  84          */
  85         public function __construct( array $params ) {
  86                 parent::__construct( $params );
  87                 $params['redisConfig']['serializer'] = 'none'; // make it easy to use Lua
  88                 $this->server = $params['redisServer'];
  89                 $this->compression = isset( $params['compression'] ) ? $params['compression'] : 'none';
  90                 $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
  91                 if ( empty( $params['daemonized'] ) ) {
  92                         throw new Exception(
  93                                 "Non-daemonized mode is no longer supported. Please install the " .
  94                                 "mediawiki/services/jobrunner service and update \$wgJobTypeConf as needed." );
  95                 }
  96         }
  97
  98         protected function supportedOrders() {
  99                 return array( 'timestamp', 'fifo' );
 100         }
 101
 102         protected function optimalOrder() {
 103                 return 'fifo';
 104         }
 105
 106         protected function supportsDelayedJobs() {
 107                 return true;
 108         }
 109
 110         /**
 111          * @see JobQueue::doIsEmpty()
 112          * @return bool
 113          * @throws MWException
 114          */
 115         protected function doIsEmpty() {
 116                 return $this->doGetSize() == 0;
 117         }
 118
 119         /**
 120          * @see JobQueue::doGetSize()
 121          * @return int
 122          * @throws MWException
 123          */
 124         protected function doGetSize() {
 125                 $conn = $this->getConnection();
 126                 try {
 127                         return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
 128                 } catch ( RedisException $e ) {
 129                         $this->throwRedisException( $conn, $e );
 130                 }
 131         }
 132
 133         /**
 134          * @see JobQueue::doGetAcquiredCount()
 135          * @return int
 136          * @throws JobQueueError
 137          */
 138         protected function doGetAcquiredCount() {
 139                 $conn = $this->getConnection();
 140                 try {
 141                         $conn->multi( Redis::PIPELINE );
 142                         $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
 143                         $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 144
 145                         return array_sum( $conn->exec() );
 146                 } catch ( RedisException $e ) {
 147                         $this->throwRedisException( $conn, $e );
 148                 }
 149         }
 150
 151         /**
 152          * @see JobQueue::doGetDelayedCount()
 153          * @return int
 154          * @throws JobQueueError
 155          */
 156         protected function doGetDelayedCount() {
 157                 $conn = $this->getConnection();
 158                 try {
 159                         return $conn->zSize( $this->getQueueKey( 'z-delayed' ) );
 160                 } catch ( RedisException $e ) {
 161                         $this->throwRedisException( $conn, $e );
 162                 }
 163         }
 164
 165         /**
 166          * @see JobQueue::doGetAbandonedCount()
 167          * @return int
 168          * @throws JobQueueError
 169          */
 170         protected function doGetAbandonedCount() {
 171                 $conn = $this->getConnection();
 172                 try {
 173                         return $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 174                 } catch ( RedisException $e ) {
 175                         $this->throwRedisException( $conn, $e );
 176                 }
 177         }
 178
 179         /**
 180          * @see JobQueue::doBatchPush()
 181          * @param array $jobs
 182          * @param int $flags
 183          * @return void
 184          * @throws JobQueueError
 185          */
 186         protected function doBatchPush( array $jobs, $flags ) {
 187                 // Convert the jobs into field maps (de-duplicated against each other)
 188                 $items = array(); // (job ID => job fields map)
 189                 foreach ( $jobs as $job ) {
 190                         $item = $this->getNewJobFields( $job );
 191                         if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
 192                                 $items[$item['sha1']] = $item;
 193                         } else {
 194                                 $items[$item['uuid']] = $item;
 195                         }
 196                 }
 197
 198                 if ( !count( $items ) ) {
 199                         return; // nothing to do
 200                 }
 201
 202                 $conn = $this->getConnection();
 203                 try {
 204                         // Actually push the non-duplicate jobs into the queue...
 205                         if ( $flags & self::QOS_ATOMIC ) {
 206                                 $batches = array( $items ); // all or nothing
 207                         } else {
 208                                 $batches = array_chunk( $items, 500 ); // avoid tying up the server
 209                         }
 210                         $failed = 0;
 211                         $pushed = 0;
 212                         foreach ( $batches as $itemBatch ) {
 213                                 $added = $this->pushBlobs( $conn, $itemBatch );
 214                                 if ( is_int( $added ) ) {
 215                                         $pushed += $added;
 216                                 } else {
 217                                         $failed += count( $itemBatch );
 218                                 }
 219                         }
 220                         if ( $failed > 0 ) {
 221                                 wfDebugLog( 'JobQueueRedis', "Could not insert {$failed} {$this->type} job(s)." );
 222
 223                                 throw new RedisException( "Could not insert {$failed} {$this->type} job(s)." );
 224                         }
 225                         JobQueue::incrStats( 'job-insert', $this->type, count( $items ) );
 226                         JobQueue::incrStats( 'job-insert-duplicate', $this->type,
 227                                 count( $items ) - $failed - $pushed );
 228                 } catch ( RedisException $e ) {
 229                         $this->throwRedisException( $conn, $e );
 230                 }
 231         }
 232
 233         /**
 234          * @param RedisConnRef $conn
 235          * @param array $items List of results from JobQueueRedis::getNewJobFields()
 236          * @return int Number of jobs inserted (duplicates are ignored)
 237          * @throws RedisException
 238          */
 239         protected function pushBlobs( RedisConnRef $conn, array $items ) {
 240                 $args = array(); // ([id, sha1, rtime, blob [, id, sha1, rtime, blob ... ] ] )
 241                 foreach ( $items as $item ) {
 242                         $args[] = (string)$item['uuid'];
 243                         $args[] = (string)$item['sha1'];
 244                         $args[] = (string)$item['rtimestamp'];
 245                         $args[] = (string)$this->serialize( $item );
 246                 }
 247                 static $script =
 248 <<<LUA
 249                 local kUnclaimed, kSha1ById, kIdBySha1, kDelayed, kData = unpack(KEYS)
 250                 if #ARGV % 4 ~= 0 then return redis.error_reply('Unmatched arguments') end
 251                 local pushed = 0
 252                 for i = 1,#ARGV,4 do
 253                         local id,sha1,rtimestamp,blob = ARGV[i],ARGV[i+1],ARGV[i+2],ARGV[i+3]
 254                         if sha1 == '' or redis.call('hExists',kIdBySha1,sha1) == 0 then
 255                                 if 1*rtimestamp > 0 then
 256                                         -- Insert into delayed queue (release time as score)
 257                                         redis.call('zAdd',kDelayed,rtimestamp,id)
 258                                 else
 259                                         -- Insert into unclaimed queue
 260                                         redis.call('lPush',kUnclaimed,id)
 261                                 end
 262                                 if sha1 ~= '' then
 263                                         redis.call('hSet',kSha1ById,id,sha1)
 264                                         redis.call('hSet',kIdBySha1,sha1,id)
 265                                 end
 266                                 redis.call('hSet',kData,id,blob)
 267                                 pushed = pushed + 1
 268                         end
 269                 end
 270                 return pushed
 271 LUA;
 272                 return $conn->luaEval( $script,
 273                         array_merge(
 274                                 array(
 275                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 276                                         $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 277                                         $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 278                                         $this->getQueueKey( 'z-delayed' ), # KEYS[4]
 279                                         $this->getQueueKey( 'h-data' ), # KEYS[5]
 280                                 ),
 281                                 $args
 282                         ),
 283                         5 # number of first argument(s) that are keys
 284                 );
 285         }
 286
 287         /**
 288          * @see JobQueue::doPop()
 289          * @return Job|bool
 290          * @throws JobQueueError
 291          */
 292         protected function doPop() {
 293                 $job = false;
 294
 295                 $conn = $this->getConnection();
 296                 try {
 297                         do {
 298                                 $blob = $this->popAndAcquireBlob( $conn );
 299                                 if ( !is_string( $blob ) ) {
 300                                         break; // no jobs; nothing to do
 301                                 }
 302
 303                                 JobQueue::incrStats( 'job-pop', $this->type );
 304                                 $item = $this->unserialize( $blob );
 305                                 if ( $item === false ) {
 306                                         wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
 307                                         continue;
 308                                 }
 309
 310                                 // If $item is invalid, the runner loop recyling will cleanup as needed
 311                                 $job = $this->getJobFromFields( $item ); // may be false
 312                         } while ( !$job ); // job may be false if invalid
 313                 } catch ( RedisException $e ) {
 314                         $this->throwRedisException( $conn, $e );
 315                 }
 316
 317                 return $job;
 318         }
 319
 320         /**
 321          * @param RedisConnRef $conn
 322          * @return array Serialized string or false
 323          * @throws RedisException
 324          */
 325         protected function popAndAcquireBlob( RedisConnRef $conn ) {
 326                 static $script =
 327 <<<LUA
 328                 local kUnclaimed, kSha1ById, kIdBySha1, kClaimed, kAttempts, kData = unpack(KEYS)
 329                 -- Pop an item off the queue
 330                 local id = redis.call('rPop',kUnclaimed)
 331                 if not id then return false end
 332                 -- Allow new duplicates of this job
 333                 local sha1 = redis.call('hGet',kSha1ById,id)
 334                 if sha1 then redis.call('hDel',kIdBySha1,sha1) end
 335                 redis.call('hDel',kSha1ById,id)
 336                 -- Mark the jobs as claimed and return it
 337                 redis.call('zAdd',kClaimed,ARGV[1],id)
 338                 redis.call('hIncrBy',kAttempts,id,1)
 339                 return redis.call('hGet',kData,id)
 340 LUA;
 341                 return $conn->luaEval( $script,
 342                         array(
 343                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 344                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 345                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 346                                 $this->getQueueKey( 'z-claimed' ), # KEYS[4]
 347                                 $this->getQueueKey( 'h-attempts' ), # KEYS[5]
 348                                 $this->getQueueKey( 'h-data' ), # KEYS[6]
 349                                 time(), # ARGV[1] (injected to be replication-safe)
 350                         ),
 351                         6 # number of first argument(s) that are keys
 352                 );
 353         }
 354
 355         /**
 356          * @see JobQueue::doAck()
 357          * @param Job $job
 358          * @return Job|bool
 359          * @throws MWException|JobQueueError
 360          */
 361         protected function doAck( Job $job ) {
 362                 if ( !isset( $job->metadata['uuid'] ) ) {
 363                         throw new MWException( "Job of type '{$job->getType()}' has no UUID." );
 364                 }
 365
 366                 $conn = $this->getConnection();
 367                 try {
 368                         static $script =
 369 <<<LUA
 370                         local kClaimed, kAttempts, kData = unpack(KEYS)
 371                         -- Unmark the job as claimed
 372                         redis.call('zRem',kClaimed,ARGV[1])
 373                         redis.call('hDel',kAttempts,ARGV[1])
 374                         -- Delete the job data itself
 375                         return redis.call('hDel',kData,ARGV[1])
 376 LUA;
 377                         $res = $conn->luaEval( $script,
 378                                 array(
 379                                         $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 380                                         $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 381                                         $this->getQueueKey( 'h-data' ), # KEYS[3]
 382                                         $job->metadata['uuid'] # ARGV[1]
 383                                 ),
 384                                 3 # number of first argument(s) that are keys
 385                         );
 386
 387                         if ( !$res ) {
 388                                 wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job." );
 389
 390                                 return false;
 391                         }
 392                 } catch ( RedisException $e ) {
 393                         $this->throwRedisException( $conn, $e );
 394                 }
 395
 396                 return true;
 397         }
 398
 399         /**
 400          * @see JobQueue::doDeduplicateRootJob()
 401          * @param Job $job
 402          * @return bool
 403          * @throws MWException|JobQueueError
 404          */
 405         protected function doDeduplicateRootJob( Job $job ) {
 406                 if ( !$job->hasRootJobParams() ) {
 407                         throw new MWException( "Cannot register root job; missing parameters." );
 408                 }
 409                 $params = $job->getRootJobParams();
 410
 411                 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
 412
 413                 $conn = $this->getConnection();
 414                 try {
 415                         $timestamp = $conn->get( $key ); // current last timestamp of this job
 416                         if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
 417                                 return true; // a newer version of this root job was enqueued
 418                         }
 419
 420                         // Update the timestamp of the last root job started at the location...
 421                         return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
 422                 } catch ( RedisException $e ) {
 423                         $this->throwRedisException( $conn, $e );
 424                 }
 425         }
 426
 427         /**
 428          * @see JobQueue::doIsRootJobOldDuplicate()
 429          * @param Job $job
 430          * @return bool
 431          * @throws JobQueueError
 432          */
 433         protected function doIsRootJobOldDuplicate( Job $job ) {
 434                 if ( !$job->hasRootJobParams() ) {
 435                         return false; // job has no de-deplication info
 436                 }
 437                 $params = $job->getRootJobParams();
 438
 439                 $conn = $this->getConnection();
 440                 try {
 441                         // Get the last time this root job was enqueued
 442                         $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
 443                 } catch ( RedisException $e ) {
 444                         $this->throwRedisException( $conn, $e );
 445                 }
 446
 447                 // Check if a new root job was started at the location after this one's...
 448                 return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
 449         }
 450
 451         /**
 452          * @see JobQueue::doDelete()
 453          * @return bool
 454          * @throws JobQueueError
 455          */
 456         protected function doDelete() {
 457                 static $props = array( 'l-unclaimed', 'z-claimed', 'z-abandoned',
 458                         'z-delayed', 'h-idBySha1', 'h-sha1ById', 'h-attempts', 'h-data' );
 459
 460                 $conn = $this->getConnection();
 461                 try {
 462                         $keys = array();
 463                         foreach ( $props as $prop ) {
 464                                 $keys[] = $this->getQueueKey( $prop );
 465                         }
 466
 467                         return ( $conn->delete( $keys ) !== false );
 468                 } catch ( RedisException $e ) {
 469                         $this->throwRedisException( $conn, $e );
 470                 }
 471         }
 472
 473         /**
 474          * @see JobQueue::getAllQueuedJobs()
 475          * @return Iterator
 476          * @throws JobQueueError
 477          */
 478         public function getAllQueuedJobs() {
 479                 $conn = $this->getConnection();
 480                 try {
 481                         $uids = $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 );
 482                 } catch ( RedisException $e ) {
 483                         $this->throwRedisException( $conn, $e );
 484                 }
 485
 486                 return $this->getJobIterator( $conn, $uids );
 487         }
 488
 489         /**
 490          * @see JobQueue::getAllDelayedJobs()
 491          * @return Iterator
 492          * @throws JobQueueError
 493          */
 494         public function getAllDelayedJobs() {
 495                 $conn = $this->getConnection();
 496                 try {
 497                         $uids = $conn->zRange( $this->getQueueKey( 'z-delayed' ), 0, -1 );
 498                 } catch ( RedisException $e ) {
 499                         $this->throwRedisException( $conn, $e );
 500                 }
 501
 502                 return $this->getJobIterator( $conn, $uids );
 503         }
 504
 505         /**
 506          * @see JobQueue::getAllAcquiredJobs()
 507          * @return Iterator
 508          * @throws JobQueueError
 509          */
 510         public function getAllAcquiredJobs() {
 511                 $conn = $this->getConnection();
 512                 try {
 513                         $uids = $conn->zRange( $this->getQueueKey( 'z-claimed' ), 0, -1 );
 514                 } catch ( RedisException $e ) {
 515                         $this->throwRedisException( $conn, $e );
 516                 }
 517
 518                 return $this->getJobIterator( $conn, $uids );
 519         }
 520
 521         /**
 522          * @see JobQueue::getAllAbandonedJobs()
 523          * @return Iterator
 524          * @throws JobQueueError
 525          */
 526         public function getAllAbandonedJobs() {
 527                 $conn = $this->getConnection();
 528                 try {
 529                         $uids = $conn->zRange( $this->getQueueKey( 'z-abandoned' ), 0, -1 );
 530                 } catch ( RedisException $e ) {
 531                         $this->throwRedisException( $conn, $e );
 532                 }
 533
 534                 return $this->getJobIterator( $conn, $uids );
 535         }
 536
 537         /**
 538          * @param RedisConnRef $conn
 539          * @param array $uids List of job UUIDs
 540          * @return MappedIterator
 541          */
 542         protected function getJobIterator( RedisConnRef $conn, array $uids ) {
 543                 $that = $this;
 544
 545                 return new MappedIterator(
 546                         $uids,
 547                         function ( $uid ) use ( $that, $conn ) {
 548                                 return $that->getJobFromUidInternal( $uid, $conn );
 549                         },
 550                         array( 'accept' => function ( $job ) {
 551                                 return is_object( $job );
 552                         } )
 553                 );
 554         }
 555
 556         public function getCoalesceLocationInternal() {
 557                 return "RedisServer:" . $this->server;
 558         }
 559
 560         protected function doGetSiblingQueuesWithJobs( array $types ) {
 561                 return array_keys( array_filter( $this->doGetSiblingQueueSizes( $types ) ) );
 562         }
 563
 564         protected function doGetSiblingQueueSizes( array $types ) {
 565                 $sizes = array(); // (type => size)
 566                 $types = array_values( $types ); // reindex
 567                 $conn = $this->getConnection();
 568                 try {
 569                         $conn->multi( Redis::PIPELINE );
 570                         foreach ( $types as $type ) {
 571                                 $conn->lSize( $this->getQueueKey( 'l-unclaimed', $type ) );
 572                         }
 573                         $res = $conn->exec();
 574                         if ( is_array( $res ) ) {
 575                                 foreach ( $res as $i => $size ) {
 576                                         $sizes[$types[$i]] = $size;
 577                                 }
 578                         }
 579                 } catch ( RedisException $e ) {
 580                         $this->throwRedisException( $conn, $e );
 581                 }
 582
 583                 return $sizes;
 584         }
 585
 586         /**
 587          * This function should not be called outside JobQueueRedis
 588          *
 589          * @param string $uid
 590          * @param RedisConnRef $conn
 591          * @return Job|bool Returns false if the job does not exist
 592          * @throws MWException|JobQueueError
 593          */
 594         public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
 595                 try {
 596                         $data = $conn->hGet( $this->getQueueKey( 'h-data' ), $uid );
 597                         if ( $data === false ) {
 598                                 return false; // not found
 599                         }
 600                         $item = $this->unserialize( $data );
 601                         if ( !is_array( $item ) ) { // this shouldn't happen
 602                                 throw new MWException( "Could not find job with ID '$uid'." );
 603                         }
 604                         $title = Title::makeTitle( $item['namespace'], $item['title'] );
 605                         $job = Job::factory( $item['type'], $title, $item['params'] );
 606                         $job->metadata['uuid'] = $item['uuid'];
 607
 608                         return $job;
 609                 } catch ( RedisException $e ) {
 610                         $this->throwRedisException( $conn, $e );
 611                 }
 612         }
 613
 614         /**
 615          * @param IJobSpecification $job
 616          * @return array
 617          */
 618         protected function getNewJobFields( IJobSpecification $job ) {
 619                 return array(
 620                         // Fields that describe the nature of the job
 621                         'type' => $job->getType(),
 622                         'namespace' => $job->getTitle()->getNamespace(),
 623                         'title' => $job->getTitle()->getDBkey(),
 624                         'params' => $job->getParams(),
 625                         // Some jobs cannot run until a "release timestamp"
 626                         'rtimestamp' => $job->getReleaseTimestamp() ?: 0,
 627                         // Additional job metadata
 628                         'uuid' => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 629                         'sha1' => $job->ignoreDuplicates()
 630                                 ? wfBaseConvert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 631                                 : '',
 632                         'timestamp' => time() // UNIX timestamp
 633                 );
 634         }
 635
 636         /**
 637          * @param array $fields
 638          * @return Job|bool
 639          */
 640         protected function getJobFromFields( array $fields ) {
 641                 $title = Title::makeTitle( $fields['namespace'], $fields['title'] );
 642                 $job = Job::factory( $fields['type'], $title, $fields['params'] );
 643                 $job->metadata['uuid'] = $fields['uuid'];
 644
 645                 return $job;
 646         }
 647
 648         /**
 649          * @param array $fields
 650          * @return string Serialized and possibly compressed version of $fields
 651          */
 652         protected function serialize( array $fields ) {
 653                 $blob = serialize( $fields );
 654                 if ( $this->compression === 'gzip'
 655                         && strlen( $blob ) >= 1024
 656                         && function_exists( 'gzdeflate' )
 657                 ) {
 658                         $object = (object)array( 'blob' => gzdeflate( $blob ), 'enc' => 'gzip' );
 659                         $blobz = serialize( $object );
 660
 661                         return ( strlen( $blobz ) < strlen( $blob ) ) ? $blobz : $blob;
 662                 } else {
 663                         return $blob;
 664                 }
 665         }
 666
 667         /**
 668          * @param string $blob
 669          * @return array|bool Unserialized version of $blob or false
 670          */
 671         protected function unserialize( $blob ) {
 672                 $fields = unserialize( $blob );
 673                 if ( is_object( $fields ) ) {
 674                         if ( $fields->enc === 'gzip' && function_exists( 'gzinflate' ) ) {
 675                                 $fields = unserialize( gzinflate( $fields->blob ) );
 676                         } else {
 677                                 $fields = false;
 678                         }
 679                 }
 680
 681                 return is_array( $fields ) ? $fields : false;
 682         }
 683
 684         /**
 685          * Get a connection to the server that handles all sub-queues for this queue
 686          *
 687          * @return RedisConnRef
 688          * @throws JobQueueConnectionError
 689          */
 690         protected function getConnection() {
 691                 $conn = $this->redisPool->getConnection( $this->server );
 692                 if ( !$conn ) {
 693                         throw new JobQueueConnectionError( "Unable to connect to redis server." );
 694                 }
 695
 696                 return $conn;
 697         }
 698
 699         /**
 700          * @param RedisConnRef $conn
 701          * @param RedisException $e
 702          * @throws JobQueueError
 703          */
 704         protected function throwRedisException( RedisConnRef $conn, $e ) {
 705                 $this->redisPool->handleError( $conn, $e );
 706                 throw new JobQueueError( "Redis server error: {$e->getMessage()}\n" );
 707         }
 708
 709         /**
 710          * @param string $prop
 711          * @param string|null $type
 712          * @return string
 713          */
 714         private function getQueueKey( $prop, $type = null ) {
 715                 $type = is_string( $type ) ? $type : $this->type;
 716                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 717                 if ( strlen( $this->key ) ) { // namespaced queue (for testing)
 718                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $this->key, $prop );
 719                 } else {
 720                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $prop );
 721                 }
 722         }
 723
 724         /**
 725          * @param string $key
 726          * @return void
 727          */
 728         public function setTestingPrefix( $key ) {
 729                 $this->key = $key;
 730         }
 731 }