includes/job/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 faster, less resource intensive, queue that JobQueueDB.
  28  * All data for a queue using this class is placed into one redis server.
  29  *
  30  * There are seven main redis keys used to track jobs:
  31  *   - l-unclaimed  : A list of job IDs used for push/pop
  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  *   - h-idBySha1   : A hash of (SHA1 => job ID) for unclaimed jobs used for de-duplication
  35  *   - h-sha1Byid   : A hash of (job ID => SHA1) for unclaimed jobs used for de-duplication
  36  *   - h-attempts   : A hash of (job ID => attempt count) used for job claiming/retries
  37  *   - h-data       : A hash of (job ID => serialized blobs) for job storage
  38  * Any given job ID can be in only one of l-unclaimed, z-claimed, and z-abandoned.
  39  * If an ID appears in any of those lists, it should have a h-data entry for its ID.
  40  * If a job has a non-empty SHA1 de-duplication value and its ID is in l-unclaimed,
  41  * then there should be no other such jobs. Every h-idBySha1 entry has an h-sha1Byid
  42  * entry and every h-sha1Byid must refer to an ID that is l-unclaimed. If a job has its
  43  * ID in z-claimed or z-abandoned, then it must also have an h-attempts entry for its ID.
  44  *
  45  * Additionally, "rootjob:* keys to track "root jobs" used for additional de-duplication.
  46  * Aside from root job keys, all keys have no expiry, and are only removed when jobs are run.
  47  * All the keys are prefixed with the relevant wiki ID information.
  48  *
  49  * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic operations.
  50  * Additionally, it should be noted that redis has different persistence modes, such
  51  * as rdb snapshots, journaling, and no persistent. Appropriate configuration should be
  52  * made on the servers based on what queues are using it and what tolerance they have.
  53  *
  54  * @ingroup JobQueue
  55  * @ingroup Redis
  56  * @since 1.21
  57  */
  58 class JobQueueRedis extends JobQueue {
  59         /** @var RedisConnectionPool */
  60         protected $redisPool;
  61
  62         protected $server; // string; server address
  63
  64         const MAX_AGE_PRUNE = 604800; // integer; seconds a job can live once claimed (7 days)
  65
  66         protected $key; // string; key to prefix the queue keys with (used for testing)
  67
  68         /**
  69          * @params include:
  70          *   - redisConfig : An array of parameters to RedisConnectionPool::__construct().
  71          *                   Note that the serializer option is ignored "none" is always used.
  72          *   - redisServer : A hostname/port combination or the absolute path of a UNIX socket.
  73          *                   If a hostname is specified but no port, the standard port number
  74          *                   6379 will be used. Required.
  75          * @param array $params
  76          */
  77         public function __construct( array $params ) {
  78                 parent::__construct( $params );
  79                 $params['redisConfig']['serializer'] = 'none'; // make it easy to use Lua
  80                 $this->server = $params['redisServer'];
  81                 $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
  82         }
  83
  84         protected function supportedOrders() {
  85                 return array( 'timestamp', 'fifo' );
  86         }
  87
  88         protected function optimalOrder() {
  89                 return 'fifo';
  90         }
  91
  92         /**
  93          * @see JobQueue::doIsEmpty()
  94          * @return bool
  95          * @throws MWException
  96          */
  97         protected function doIsEmpty() {
  98                 return $this->doGetSize() == 0;
  99         }
 100
 101         /**
 102          * @see JobQueue::doGetSize()
 103          * @return integer
 104          * @throws MWException
 105          */
 106         protected function doGetSize() {
 107                 $conn = $this->getConnection();
 108                 try {
 109                         return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
 110                 } catch ( RedisException $e ) {
 111                         $this->throwRedisException( $this->server, $conn, $e );
 112                 }
 113         }
 114
 115         /**
 116          * @see JobQueue::doGetAcquiredCount()
 117          * @return integer
 118          * @throws MWException
 119          */
 120         protected function doGetAcquiredCount() {
 121                 if ( $this->claimTTL <= 0 ) {
 122                         return 0; // no acknowledgements
 123                 }
 124                 $conn = $this->getConnection();
 125                 try {
 126                         $conn->multi( Redis::PIPELINE );
 127                         $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
 128                         $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 129                         return array_sum( $conn->exec() );
 130                 } catch ( RedisException $e ) {
 131                         $this->throwRedisException( $this->server, $conn, $e );
 132                 }
 133         }
 134
 135         /**
 136          * @see JobQueue::doBatchPush()
 137          * @param array $jobs
 138          * @param $flags
 139          * @return bool
 140          * @throws MWException
 141          */
 142         protected function doBatchPush( array $jobs, $flags ) {
 143                 // Convert the jobs into field maps (de-duplicated against each other)
 144                 $items = array(); // (job ID => job fields map)
 145                 foreach ( $jobs as $job ) {
 146                         $item = $this->getNewJobFields( $job );
 147                         if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
 148                                 $items[$item['sha1']] = $item;
 149                         } else {
 150                                 $items[$item['uuid']] = $item;
 151                         }
 152                 }
 153                 // Convert the field maps into serialized blobs
 154                 $tuples = array();
 155                 foreach ( $items as $item ) {
 156                         $tuples[] = array( $item['uuid'], $item['sha1'], serialize( $item ) );
 157                 }
 158
 159                 if ( !count( $tuples ) ) {
 160                         return true; // nothing to do
 161                 }
 162
 163                 $conn = $this->getConnection();
 164                 try {
 165                         // Actually push the non-duplicate jobs into the queue...
 166                         if ( $flags & self::QoS_Atomic ) {
 167                                 $batches = array( $tuples ); // all or nothing
 168                         } else {
 169                                 $batches = array_chunk( $tuples, 500 ); // avoid tying up the server
 170                         }
 171                         $failed = 0;
 172                         $pushed = 0;
 173                         foreach ( $batches as $tupleBatch ) {
 174                                 $added = $this->pushBlobs( $conn, $tupleBatch );
 175                                 if ( is_int( $added ) ) {
 176                                         $pushed += $added;
 177                                 } else {
 178                                         $failed += count( $tupleBatch );
 179                                 }
 180                         }
 181                         if ( $failed > 0 ) {
 182                                 wfDebugLog( 'JobQueueRedis', "Could not insert {$failed} {$this->type} job(s)." );
 183                                 return false;
 184                         }
 185                         wfIncrStats( 'job-insert', count( $tuples ) );
 186                         wfIncrStats( 'job-insert-duplicate', count( $tuples ) - $failed - $pushed );
 187                 } catch ( RedisException $e ) {
 188                         $this->throwRedisException( $this->server, $conn, $e );
 189                 }
 190
 191                 return true;
 192         }
 193
 194         /**
 195          * @param RedisConnRef $conn
 196          * @param array $tuples List of tuples of (job ID, job SHA1 or '', serialized blob)
 197          * @return integer Number of jobs inserted (duplicates are ignored)
 198          * @throws RedisException
 199          */
 200         protected function pushBlobs( RedisConnRef $conn, array $tuples ) {
 201                 $args = array(); // ([id, sha1, blob [, id, sha1, blob ... ] ] )
 202                 foreach ( $tuples as $tuple ) {
 203                         $args[] = $tuple[0]; // id
 204                         $args[] = $tuple[1]; // sha1
 205                         $args[] = $tuple[2]; // blob
 206                 }
 207                 static $script =
 208 <<<LUA
 209                 if #ARGV % 3 ~= 0 then return redis.error_reply('Unmatched arguments') end
 210                 local pushed = 0
 211                 for i = 1,#ARGV,3 do
 212                         local id,sha1,blob = ARGV[i],ARGV[i+1],ARGV[i+2]
 213                         if sha1 == '' or redis.call('hExists',KEYS[3],sha1) == 0 then
 214                                 redis.call('lPush',KEYS[1],id)
 215                                 if sha1 ~= '' then
 216                                         redis.call('hSet',KEYS[2],id,sha1)
 217                                         redis.call('hSet',KEYS[3],sha1,id)
 218                                 end
 219                                 redis.call('hSet',KEYS[4],id,blob)
 220                                 pushed = pushed + 1
 221                         end
 222                 end
 223                 return pushed
 224 LUA;
 225                 return $this->redisEval( $conn, $script,
 226                         array_merge(
 227                                 array(
 228                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 229                                         $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 230                                         $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 231                                         $this->getQueueKey( 'h-data' ), # KEYS[4]
 232                                 ),
 233                                 $args
 234                         ),
 235                         4 # number of first argument(s) that are keys
 236                 );
 237         }
 238
 239         /**
 240          * @see JobQueue::doPop()
 241          * @return Job|bool
 242          * @throws MWException
 243          */
 244         protected function doPop() {
 245                 $job = false;
 246
 247                 $conn = $this->getConnection();
 248                 try {
 249                         do {
 250                                 if ( $this->claimTTL > 0 ) {
 251                                         // Keep the claimed job list down for high-traffic queues
 252                                         if ( mt_rand( 0, 99 ) == 0 ) {
 253                                                 $this->recycleAndDeleteStaleJobs();
 254                                         }
 255                                         $blob = $this->popAndAcquireBlob( $conn );
 256                                 } else {
 257                                         $blob = $this->popAndDeleteBlob( $conn );
 258                                 }
 259                                 if ( $blob === false ) {
 260                                         break; // no jobs; nothing to do
 261                                 }
 262
 263                                 wfIncrStats( 'job-pop' );
 264                                 $item = unserialize( $blob );
 265                                 if ( $item === false ) {
 266                                         wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
 267                                         continue;
 268                                 }
 269
 270                                 // If $item is invalid, recycleAndDeleteStaleJobs() will cleanup as needed
 271                                 $job = $this->getJobFromFields( $item ); // may be false
 272                         } while ( !$job ); // job may be false if invalid
 273                 } catch ( RedisException $e ) {
 274                         $this->throwRedisException( $this->server, $conn, $e );
 275                 }
 276
 277                 return $job;
 278         }
 279
 280         /**
 281          * @param RedisConnRef $conn
 282          * @return array serialized string or false
 283          * @throws RedisException
 284          */
 285         protected function popAndDeleteBlob( RedisConnRef $conn ) {
 286                 static $script =
 287 <<<LUA
 288                 -- Pop an item off the queue
 289                 local id = redis.call('rpop',KEYS[1])
 290                 if not id then return false end
 291                 -- Get the job data and remove it
 292                 local item = redis.call('hGet',KEYS[4],id)
 293                 redis.call('hDel',KEYS[4],id)
 294                 -- Allow new duplicates of this job
 295                 local sha1 = redis.call('hGet',KEYS[2],id)
 296                 if sha1 then redis.call('hDel',KEYS[3],sha1) end
 297                 redis.call('hDel',KEYS[2],id)
 298                 -- Return the job data
 299                 return item
 300 LUA;
 301                 return $this->redisEval( $conn, $script,
 302                         array(
 303                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 304                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 305                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 306                                 $this->getQueueKey( 'h-data' ), # KEYS[4]
 307                         ),
 308                         4 # number of first argument(s) that are keys
 309                 );
 310         }
 311
 312         /**
 313          * @param RedisConnRef $conn
 314          * @return array serialized string or false
 315          * @throws RedisException
 316          */
 317         protected function popAndAcquireBlob( RedisConnRef $conn ) {
 318                 static $script =
 319 <<<LUA
 320                 -- Pop an item off the queue
 321                 local id = redis.call('rPop',KEYS[1])
 322                 if not id then return false end
 323                 -- Allow new duplicates of this job
 324                 local sha1 = redis.call('hGet',KEYS[2],id)
 325                 if sha1 then redis.call('hDel',KEYS[3],sha1) end
 326                 redis.call('hDel',KEYS[2],id)
 327                 -- Mark the jobs as claimed and return it
 328                 redis.call('zAdd',KEYS[4],ARGV[1],id)
 329                 redis.call('hIncrBy',KEYS[5],id,1)
 330                 return redis.call('hGet',KEYS[6],id)
 331 LUA;
 332                 return $this->redisEval( $conn, $script,
 333                         array(
 334                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 335                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 336                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 337                                 $this->getQueueKey( 'z-claimed' ), # KEYS[4]
 338                                 $this->getQueueKey( 'h-attempts' ), # KEYS[5]
 339                                 $this->getQueueKey( 'h-data' ), # KEYS[6]
 340                                 time(), # ARGV[1] (injected to be replication-safe)
 341                         ),
 342                         6 # number of first argument(s) that are keys
 343                 );
 344         }
 345
 346         /**
 347          * @see JobQueue::doAck()
 348          * @param Job $job
 349          * @return Job|bool
 350          * @throws MWException
 351          */
 352         protected function doAck( Job $job ) {
 353                 if ( $this->claimTTL > 0 ) {
 354                         $conn = $this->getConnection();
 355                         try {
 356                                 // Get the exact field map this Job came from, regardless of whether
 357                                 // the job was transformed into a DuplicateJob or anything of the sort.
 358                                 $item = $job->metadata['sourceFields'];
 359
 360                                 static $script =
 361 <<<LUA
 362                                 -- Unmark the job as claimed
 363                                 redis.call('zRem',KEYS[1],ARGV[1])
 364                                 redis.call('hDel',KEYS[2],ARGV[1])
 365                                 -- Delete the job data itself
 366                                 return redis.call('hDel',KEYS[3],ARGV[1])
 367 LUA;
 368                                 $res = $this->redisEval( $conn, $script,
 369                                         array(
 370                                                 $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 371                                                 $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 372                                                 $this->getQueueKey( 'h-data' ), # KEYS[3]
 373                                                 $item['uuid'] # ARGV[1]
 374                                         ),
 375                                         3 # number of first argument(s) that are keys
 376                                 );
 377
 378                                 if ( !$res ) {
 379                                         wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job." );
 380                                         return false;
 381                                 }
 382                         } catch ( RedisException $e ) {
 383                                 $this->throwRedisException( $this->server, $conn, $e );
 384                         }
 385                 }
 386                 return true;
 387         }
 388
 389         /**
 390          * @see JobQueue::doDeduplicateRootJob()
 391          * @param Job $job
 392          * @return bool
 393          * @throws MWException
 394          */
 395         protected function doDeduplicateRootJob( Job $job ) {
 396                 $params = $job->getParams();
 397                 if ( !isset( $params['rootJobSignature'] ) ) {
 398                         throw new MWException( "Cannot register root job; missing 'rootJobSignature'." );
 399                 } elseif ( !isset( $params['rootJobTimestamp'] ) ) {
 400                         throw new MWException( "Cannot register root job; missing 'rootJobTimestamp'." );
 401                 }
 402                 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
 403
 404                 $conn = $this->getConnection();
 405                 try {
 406                         $timestamp = $conn->get( $key ); // current last timestamp of this job
 407                         if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
 408                                 return true; // a newer version of this root job was enqueued
 409                         }
 410                         // Update the timestamp of the last root job started at the location...
 411                         return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
 412                 } catch ( RedisException $e ) {
 413                         $this->throwRedisException( $this->server, $conn, $e );
 414                 }
 415         }
 416
 417         /**
 418          * @see JobQueue::doIsRootJobOldDuplicate()
 419          * @param Job $job
 420          * @return bool
 421          */
 422         protected function doIsRootJobOldDuplicate( Job $job ) {
 423                 $params = $job->getParams();
 424                 if ( !isset( $params['rootJobSignature'] ) ) {
 425                         return false; // job has no de-deplication info
 426                 } elseif ( !isset( $params['rootJobTimestamp'] ) ) {
 427                         wfDebugLog( 'JobQueueRedis', "Cannot check root job; missing 'rootJobTimestamp'." );
 428                         return false;
 429                 }
 430
 431                 $conn = $this->getConnection();
 432                 try {
 433                         // Get the last time this root job was enqueued
 434                         $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
 435                 } catch ( RedisException $e ) {
 436                         $this->throwRedisException( $this->server, $conn, $e );
 437                 }
 438
 439                 // Check if a new root job was started at the location after this one's...
 440                 return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
 441         }
 442
 443         /**
 444          * @see JobQueue::getAllQueuedJobs()
 445          * @return Iterator
 446          */
 447         public function getAllQueuedJobs() {
 448                 $conn = $this->getConnection();
 449                 if ( !$conn ) {
 450                         throw new MWException( "Unable to connect to redis server." );
 451                 }
 452                 try {
 453                         $that = $this;
 454                         return new MappedIterator(
 455                                 $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 ),
 456                                 function( $uid ) use ( $that, $conn ) {
 457                                         return $that->getJobFromUidInternal( $uid, $conn );
 458                                 }
 459                         );
 460                 } catch ( RedisException $e ) {
 461                         $this->throwRedisException( $this->server, $conn, $e );
 462                 }
 463         }
 464
 465         /**
 466          * This function should not be called outside RedisJobQueue
 467          *
 468          * @param $uid string
 469          * @param $conn RedisConnRef
 470          * @return Job
 471          * @throws MWException
 472          */
 473         public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
 474                 try {
 475                         $item = unserialize( $conn->hGet( $this->getQueueKey( 'h-data' ), $uid ) );
 476                         if ( !is_array( $item ) ) { // this shouldn't happen
 477                                 throw new MWException( "Could not find job with ID '$uid'." );
 478                         }
 479                         $title = Title::makeTitle( $item['namespace'], $item['title'] );
 480                         $job = Job::factory( $item['type'], $title, $item['params'] );
 481                         $job->metadata['sourceFields'] = $item;
 482                         return $job;
 483                 } catch ( RedisException $e ) {
 484                         $this->throwRedisException( $this->server, $conn, $e );
 485                 }
 486         }
 487
 488         /**
 489          * Recycle or destroy any jobs that have been claimed for too long
 490          *
 491          * @return integer Number of jobs recycled/deleted
 492          * @throws MWException
 493          */
 494         public function recycleAndDeleteStaleJobs() {
 495                 if ( $this->claimTTL <= 0 ) { // sanity
 496                         throw new MWException( "Cannot recycle jobs since acknowledgements are disabled." );
 497                 }
 498                 $count = 0;
 499                 // For each job item that can be retried, we need to add it back to the
 500                 // main queue and remove it from the list of currenty claimed job items.
 501                 // For those that cannot, they are marked as dead and kept around for
 502                 // investigation and manual job restoration but are eventually deleted.
 503                 $conn = $this->getConnection();
 504                 try {
 505                         $now = time();
 506                         static $script =
 507 <<<LUA
 508                         local released,abandoned,pruned = 0,0,0
 509                         -- Get all non-dead jobs that have an expired claim on them.
 510                         -- The score for each item is the last claim timestamp (UNIX).
 511                         local staleClaims = redis.call('zRangeByScore',KEYS[1],0,ARGV[1],'WITHSCORES')
 512                         for id,timestamp in ipairs(staleClaims) do
 513                                 local attempts = redis.call('hGet',KEYS[2],id)
 514                                 if attempts < ARGV[3] then
 515                                         -- Claim expired and retries left: re-enqueue the job
 516                                         redis.call('lPush',KEYS[3],id)
 517                                         redis.call('hIncrBy',KEYS[2],id,1)
 518                                         released = released + 1
 519                                 else
 520                                         -- Claim expired and no retries left: mark the job as dead
 521                                         redis.call('zAdd',KEYS[5],timestamp,id)
 522                                         abandoned = abandoned + 1
 523                                 end
 524                                 redis.call('zRem',KEYS[1],id)
 525                         end
 526                         -- Get all of the dead jobs that have been marked as dead for too long.
 527                         -- The score for each item is the last claim timestamp (UNIX).
 528                         local deadClaims = redis.call('zRangeByScore',KEYS[5],0,ARGV[2],'WITHSCORES')
 529                         for id,timestamp in ipairs(deadClaims) do
 530                                 -- Stale and out of retries: remove any traces of the job
 531                                 redis.call('zRem',KEYS[5],id)
 532                                 redis.call('hDel',KEYS[2],id)
 533                                 redis.call('hDel',KEYS[4],id)
 534                                 pruned = pruned + 1
 535                         end
 536                         return {released,abandoned,pruned}
 537 LUA;
 538                         $res = $this->redisEval( $conn, $script,
 539                                 array(
 540                                         $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 541                                         $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 542                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[3]
 543                                         $this->getQueueKey( 'h-data' ), # KEYS[4]
 544                                         $this->getQueueKey( 'z-abandoned' ), # KEYS[5]
 545                                         $now - $this->claimTTL, # ARGV[1]
 546                                         $now - self::MAX_AGE_PRUNE, # ARGV[2]
 547                                         $this->maxTries # ARGV[3]
 548                                 ),
 549                                 5 # number of first argument(s) that are keys
 550                         );
 551                         if ( $res ) {
 552                                 list( $released, $abandoned, $pruned ) = $res;
 553                                 $count += $released + $pruned;
 554                                 wfIncrStats( 'job-recycle', count( $released ) );
 555                         }
 556                 } catch ( RedisException $e ) {
 557                         $this->throwRedisException( $this->server, $conn, $e );
 558                 }
 559
 560                 return $count;
 561         }
 562
 563         /**
 564          * @return Array
 565          */
 566         protected function doGetPeriodicTasks() {
 567                 if ( $this->claimTTL > 0 ) {
 568                         return array(
 569                                 'recycleAndDeleteStaleJobs' => array(
 570                                         'callback' => array( $this, 'recycleAndDeleteStaleJobs' ),
 571                                         'period'   => ceil( $this->claimTTL / 2 )
 572                                 )
 573                         );
 574                 } else {
 575                         return array();
 576                 }
 577         }
 578
 579         /**
 580          * @param RedisConnRef $conn
 581          * @param string $script
 582          * @param array $params
 583          * @param integer $numKeys
 584          * @return mixed
 585          */
 586         protected function redisEval( RedisConnRef $conn, $script, array $params, $numKeys ) {
 587                 $res = $conn->evalSha( sha1( $script ), $params, $numKeys );
 588                 if ( $res === false && $conn->getLastError() != '' ) { // not in script cache?
 589                         wfDebugLog( 'JobQueueRedis', "Lua script error: " . $conn->getLastError() );
 590                         $res = $conn->eval( $script, $params, $numKeys );
 591                 }
 592                 return $res;
 593         }
 594
 595         /**
 596          * @param $job Job
 597          * @return array
 598          */
 599         protected function getNewJobFields( Job $job ) {
 600                 return array(
 601                         // Fields that describe the nature of the job
 602                         'type'      => $job->getType(),
 603                         'namespace' => $job->getTitle()->getNamespace(),
 604                         'title'     => $job->getTitle()->getDBkey(),
 605                         'params'    => $job->getParams(),
 606                         // Additional job metadata
 607                         'uuid'      => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 608                         'sha1'      => $job->ignoreDuplicates()
 609                                 ? wfBaseConvert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 610                                 : '',
 611                         'timestamp' => time() // UNIX timestamp
 612                 );
 613         }
 614
 615         /**
 616          * @param $fields array
 617          * @return Job|bool
 618          */
 619         protected function getJobFromFields( array $fields ) {
 620                 $title = Title::makeTitleSafe( $fields['namespace'], $fields['title'] );
 621                 if ( $title ) {
 622                         $job = Job::factory( $fields['type'], $title, $fields['params'] );
 623                         $job->metadata['sourceFields'] = $fields;
 624                         return $job;
 625                 }
 626                 return false;
 627         }
 628
 629         /**
 630          * Get a connection to the server that handles all sub-queues for this queue
 631          *
 632          * @return Array (server name, Redis instance)
 633          * @throws MWException
 634          */
 635         protected function getConnection() {
 636                 $conn = $this->redisPool->getConnection( $this->server );
 637                 if ( !$conn ) {
 638                         throw new MWException( "Unable to connect to redis server." );
 639                 }
 640                 return $conn;
 641         }
 642
 643         /**
 644          * @param $server string
 645          * @param $conn RedisConnRef
 646          * @param $e RedisException
 647          * @throws MWException
 648          */
 649         protected function throwRedisException( $server, RedisConnRef $conn, $e ) {
 650                 $this->redisPool->handleException( $server, $conn, $e );
 651                 throw new MWException( "Redis server error: {$e->getMessage()}\n" );
 652         }
 653
 654         /**
 655          * @param $prop string
 656          * @return string
 657          */
 658         private function getQueueKey( $prop ) {
 659                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 660                 if ( strlen( $this->key ) ) { // namespaced queue (for testing)
 661                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $this->type, $this->key, $prop );
 662                 } else {
 663                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $this->type, $prop );
 664                 }
 665         }
 666
 667         /**
 668          * @param $key string
 669          * @return void
 670          */
 671         public function setTestingPrefix( $key ) {
 672                 $this->key = $key;
 673         }
 674 }