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  * The mediawiki/services/jobrunner background service must be set up and running.
  30  *
  31  * There are eight main redis keys (per queue) used to track jobs:
  32  *   - l-unclaimed  : A list of job IDs used for ready unclaimed jobs
  33  *   - z-claimed    : A sorted set of (job ID, UNIX timestamp as score) used for job retries
  34  *   - z-abandoned  : A sorted set of (job ID, UNIX timestamp as score) used for broken jobs
  35  *   - z-delayed    : A sorted set of (job ID, UNIX timestamp as score) used for delayed jobs
  36  *   - h-idBySha1   : A hash of (SHA1 => job ID) for unclaimed jobs used for de-duplication
  37  *   - h-sha1ById   : A hash of (job ID => SHA1) for unclaimed jobs used for de-duplication
  38  *   - h-attempts   : A hash of (job ID => attempt count) used for job claiming/retries
  39  *   - h-data       : A hash of (job ID => serialized blobs) for job storage
  40  * A job ID can be in only one of z-delayed, l-unclaimed, z-claimed, and z-abandoned.
  41  * If an ID appears in any of those lists, it should have a h-data entry for its ID.
  42  * If a job has a SHA1 de-duplication value and its ID is in l-unclaimed or z-delayed, then
  43  * there should be no other such jobs with that SHA1. Every h-idBySha1 entry has an h-sha1ById
  44  * entry and every h-sha1ById must refer to an ID that is l-unclaimed. If a job has its
  45  * ID in z-claimed or z-abandoned, then it must also have an h-attempts entry for its ID.
  46  *
  47  * The following keys are used to track queue states:
  48  *   - s-queuesWithJobs : A set of all queues with non-abandoned jobs
  49  *
  50  * The background service takes care of undelaying, recycling, and pruning jobs as well as
  51  * removing s-queuesWithJobs entries as queues empty.
  52  *
  53  * Additionally, "rootjob:* keys track "root jobs" used for additional de-duplication.
  54  * Aside from root job keys, all keys have no expiry, and are only removed when jobs are run.
  55  * All the keys are prefixed with the relevant wiki ID information.
  56  *
  57  * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic operations.
  58  * Additionally, it should be noted that redis has different persistence modes, such
  59  * as rdb snapshots, journaling, and no persistence. Appropriate configuration should be
  60  * made on the servers based on what queues are using it and what tolerance they have.
  61  *
  62  * @ingroup JobQueue
  63  * @ingroup Redis
  64  * @since 1.22
  65  */
  66 class JobQueueRedis extends JobQueue {
  67         /** @var RedisConnectionPool */
  68         protected $redisPool;
  69
  70         /** @var string Server address */
  71         protected $server;
  72         /** @var string Compression method to use */
  73         protected $compression;
  74
  75         const MAX_AGE_PRUNE = 604800; // integer; seconds a job can live once claimed (7 days)
  76
  77         /** @var string Key to prefix the queue keys with (used for testing) */
  78         protected $key;
  79
  80         /**
  81          * @param array $params Possible keys:
  82          *   - redisConfig : An array of parameters to RedisConnectionPool::__construct().
  83          *                   Note that the serializer option is ignored as "none" is always used.
  84          *   - redisServer : A hostname/port combination or the absolute path of a UNIX socket.
  85          *                   If a hostname is specified but no port, the standard port number
  86          *                   6379 will be used. Required.
  87          *   - compression : The type of compression to use; one of (none,gzip).
  88          *   - daemonized  : Set to true if the redisJobRunnerService runs in the background.
  89          *                   This will disable job recycling/undelaying from the MediaWiki side
  90          *                   to avoid redundance and out-of-sync configuration.
  91          * @throws InvalidArgumentException
  92          */
  93         public function __construct( array $params ) {
  94                 parent::__construct( $params );
  95                 $params['redisConfig']['serializer'] = 'none'; // make it easy to use Lua
  96                 $this->server = $params['redisServer'];
  97                 $this->compression = isset( $params['compression'] ) ? $params['compression'] : 'none';
  98                 $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
  99                 if ( empty( $params['daemonized'] ) ) {
 100                         throw new InvalidArgumentException(
 101                                 "Non-daemonized mode is no longer supported. Please install the " .
 102                                 "mediawiki/services/jobrunner service and update \$wgJobTypeConf as needed." );
 103                 }
 104         }
 105
 106         protected function supportedOrders() {
 107                 return [ 'timestamp', 'fifo' ];
 108         }
 109
 110         protected function optimalOrder() {
 111                 return 'fifo';
 112         }
 113
 114         protected function supportsDelayedJobs() {
 115                 return true;
 116         }
 117
 118         /**
 119          * @see JobQueue::doIsEmpty()
 120          * @return bool
 121          * @throws JobQueueError
 122          */
 123         protected function doIsEmpty() {
 124                 return $this->doGetSize() == 0;
 125         }
 126
 127         /**
 128          * @see JobQueue::doGetSize()
 129          * @return int
 130          * @throws JobQueueError
 131          */
 132         protected function doGetSize() {
 133                 $conn = $this->getConnection();
 134                 try {
 135                         return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
 136                 } catch ( RedisException $e ) {
 137                         $this->throwRedisException( $conn, $e );
 138                 }
 139         }
 140
 141         /**
 142          * @see JobQueue::doGetAcquiredCount()
 143          * @return int
 144          * @throws JobQueueError
 145          */
 146         protected function doGetAcquiredCount() {
 147                 $conn = $this->getConnection();
 148                 try {
 149                         $conn->multi( Redis::PIPELINE );
 150                         $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
 151                         $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 152
 153                         return array_sum( $conn->exec() );
 154                 } catch ( RedisException $e ) {
 155                         $this->throwRedisException( $conn, $e );
 156                 }
 157         }
 158
 159         /**
 160          * @see JobQueue::doGetDelayedCount()
 161          * @return int
 162          * @throws JobQueueError
 163          */
 164         protected function doGetDelayedCount() {
 165                 $conn = $this->getConnection();
 166                 try {
 167                         return $conn->zSize( $this->getQueueKey( 'z-delayed' ) );
 168                 } catch ( RedisException $e ) {
 169                         $this->throwRedisException( $conn, $e );
 170                 }
 171         }
 172
 173         /**
 174          * @see JobQueue::doGetAbandonedCount()
 175          * @return int
 176          * @throws JobQueueError
 177          */
 178         protected function doGetAbandonedCount() {
 179                 $conn = $this->getConnection();
 180                 try {
 181                         return $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 182                 } catch ( RedisException $e ) {
 183                         $this->throwRedisException( $conn, $e );
 184                 }
 185         }
 186
 187         /**
 188          * @see JobQueue::doBatchPush()
 189          * @param IJobSpecification[] $jobs
 190          * @param int $flags
 191          * @return void
 192          * @throws JobQueueError
 193          */
 194         protected function doBatchPush( array $jobs, $flags ) {
 195                 // Convert the jobs into field maps (de-duplicated against each other)
 196                 $items = []; // (job ID => job fields map)
 197                 foreach ( $jobs as $job ) {
 198                         $item = $this->getNewJobFields( $job );
 199                         if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
 200                                 $items[$item['sha1']] = $item;
 201                         } else {
 202                                 $items[$item['uuid']] = $item;
 203                         }
 204                 }
 205
 206                 if ( !count( $items ) ) {
 207                         return; // nothing to do
 208                 }
 209
 210                 $conn = $this->getConnection();
 211                 try {
 212                         // Actually push the non-duplicate jobs into the queue...
 213                         if ( $flags & self::QOS_ATOMIC ) {
 214                                 $batches = [ $items ]; // all or nothing
 215                         } else {
 216                                 $batches = array_chunk( $items, 100 ); // avoid tying up the server
 217                         }
 218                         $failed = 0;
 219                         $pushed = 0;
 220                         foreach ( $batches as $itemBatch ) {
 221                                 $added = $this->pushBlobs( $conn, $itemBatch );
 222                                 if ( is_int( $added ) ) {
 223                                         $pushed += $added;
 224                                 } else {
 225                                         $failed += count( $itemBatch );
 226                                 }
 227                         }
 228                         JobQueue::incrStats( 'inserts', $this->type, count( $items ) );
 229                         JobQueue::incrStats( 'inserts_actual', $this->type, $pushed );
 230                         JobQueue::incrStats( 'dupe_inserts', $this->type,
 231                                 count( $items ) - $failed - $pushed );
 232                         if ( $failed > 0 ) {
 233                                 $err = "Could not insert {$failed} {$this->type} job(s).";
 234                                 wfDebugLog( 'JobQueueRedis', $err );
 235                                 throw new RedisException( $err );
 236                         }
 237                 } catch ( RedisException $e ) {
 238                         $this->throwRedisException( $conn, $e );
 239                 }
 240         }
 241
 242         /**
 243          * @param RedisConnRef $conn
 244          * @param array $items List of results from JobQueueRedis::getNewJobFields()
 245          * @return int Number of jobs inserted (duplicates are ignored)
 246          * @throws RedisException
 247          */
 248         protected function pushBlobs( RedisConnRef $conn, array $items ) {
 249                 $args = [ $this->encodeQueueName() ];
 250                 // Next args come in 4s ([id, sha1, rtime, blob [, id, sha1, rtime, blob ... ] ] )
 251                 foreach ( $items as $item ) {
 252                         $args[] = (string)$item['uuid'];
 253                         $args[] = (string)$item['sha1'];
 254                         $args[] = (string)$item['rtimestamp'];
 255                         $args[] = (string)$this->serialize( $item );
 256                 }
 257                 static $script =
 258 <<<LUA
 259                 local kUnclaimed, kSha1ById, kIdBySha1, kDelayed, kData, kQwJobs = unpack(KEYS)
 260                 -- First argument is the queue ID
 261                 local queueId = ARGV[1]
 262                 -- Next arguments all come in 4s (one per job)
 263                 local variadicArgCount = #ARGV - 1
 264                 if variadicArgCount % 4 ~= 0 then
 265                         return redis.error_reply('Unmatched arguments')
 266                 end
 267                 -- Insert each job into this queue as needed
 268                 local pushed = 0
 269                 for i = 2,#ARGV,4 do
 270                         local id,sha1,rtimestamp,blob = ARGV[i],ARGV[i+1],ARGV[i+2],ARGV[i+3]
 271                         if sha1 == '' or redis.call('hExists',kIdBySha1,sha1) == 0 then
 272                                 if 1*rtimestamp > 0 then
 273                                         -- Insert into delayed queue (release time as score)
 274                                         redis.call('zAdd',kDelayed,rtimestamp,id)
 275                                 else
 276                                         -- Insert into unclaimed queue
 277                                         redis.call('lPush',kUnclaimed,id)
 278                                 end
 279                                 if sha1 ~= '' then
 280                                         redis.call('hSet',kSha1ById,id,sha1)
 281                                         redis.call('hSet',kIdBySha1,sha1,id)
 282                                 end
 283                                 redis.call('hSet',kData,id,blob)
 284                                 pushed = pushed + 1
 285                         end
 286                 end
 287                 -- Mark this queue as having jobs
 288                 redis.call('sAdd',kQwJobs,queueId)
 289                 return pushed
 290 LUA;
 291                 return $conn->luaEval( $script,
 292                         array_merge(
 293                                 [
 294                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 295                                         $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 296                                         $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 297                                         $this->getQueueKey( 'z-delayed' ), # KEYS[4]
 298                                         $this->getQueueKey( 'h-data' ), # KEYS[5]
 299                                         $this->getGlobalKey( 's-queuesWithJobs' ), # KEYS[6]
 300                                 ],
 301                                 $args
 302                         ),
 303                         6 # number of first argument(s) that are keys
 304                 );
 305         }
 306
 307         /**
 308          * @see JobQueue::doPop()
 309          * @return Job|bool
 310          * @throws JobQueueError
 311          */
 312         protected function doPop() {
 313                 $job = false;
 314
 315                 $conn = $this->getConnection();
 316                 try {
 317                         do {
 318                                 $blob = $this->popAndAcquireBlob( $conn );
 319                                 if ( !is_string( $blob ) ) {
 320                                         break; // no jobs; nothing to do
 321                                 }
 322
 323                                 JobQueue::incrStats( 'pops', $this->type );
 324                                 $item = $this->unserialize( $blob );
 325                                 if ( $item === false ) {
 326                                         wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
 327                                         continue;
 328                                 }
 329
 330                                 // If $item is invalid, the runner loop recyling will cleanup as needed
 331                                 $job = $this->getJobFromFields( $item ); // may be false
 332                         } while ( !$job ); // job may be false if invalid
 333                 } catch ( RedisException $e ) {
 334                         $this->throwRedisException( $conn, $e );
 335                 }
 336
 337                 return $job;
 338         }
 339
 340         /**
 341          * @param RedisConnRef $conn
 342          * @return array Serialized string or false
 343          * @throws RedisException
 344          */
 345         protected function popAndAcquireBlob( RedisConnRef $conn ) {
 346                 static $script =
 347 <<<LUA
 348                 local kUnclaimed, kSha1ById, kIdBySha1, kClaimed, kAttempts, kData = unpack(KEYS)
 349                 local rTime = unpack(ARGV)
 350                 -- Pop an item off the queue
 351                 local id = redis.call('rPop',kUnclaimed)
 352                 if not id then
 353                         return false
 354                 end
 355                 -- Allow new duplicates of this job
 356                 local sha1 = redis.call('hGet',kSha1ById,id)
 357                 if sha1 then redis.call('hDel',kIdBySha1,sha1) end
 358                 redis.call('hDel',kSha1ById,id)
 359                 -- Mark the jobs as claimed and return it
 360                 redis.call('zAdd',kClaimed,rTime,id)
 361                 redis.call('hIncrBy',kAttempts,id,1)
 362                 return redis.call('hGet',kData,id)
 363 LUA;
 364                 return $conn->luaEval( $script,
 365                         [
 366                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 367                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 368                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 369                                 $this->getQueueKey( 'z-claimed' ), # KEYS[4]
 370                                 $this->getQueueKey( 'h-attempts' ), # KEYS[5]
 371                                 $this->getQueueKey( 'h-data' ), # KEYS[6]
 372                                 time(), # ARGV[1] (injected to be replication-safe)
 373                         ],
 374                         6 # number of first argument(s) that are keys
 375                 );
 376         }
 377
 378         /**
 379          * @see JobQueue::doAck()
 380          * @param Job $job
 381          * @return Job|bool
 382          * @throws UnexpectedValueException
 383          * @throws JobQueueError
 384          */
 385         protected function doAck( Job $job ) {
 386                 if ( !isset( $job->metadata['uuid'] ) ) {
 387                         throw new UnexpectedValueException( "Job of type '{$job->getType()}' has no UUID." );
 388                 }
 389
 390                 $uuid = $job->metadata['uuid'];
 391                 $conn = $this->getConnection();
 392                 try {
 393                         static $script =
 394 <<<LUA
 395                         local kClaimed, kAttempts, kData = unpack(KEYS)
 396                         local uuid = unpack(ARGV)
 397                         -- Unmark the job as claimed
 398                         redis.call('zRem',kClaimed,uuid)
 399                         redis.call('hDel',kAttempts,uuid)
 400                         -- Delete the job data itself
 401                         return redis.call('hDel',kData,uuid)
 402 LUA;
 403                         $res = $conn->luaEval( $script,
 404                                 [
 405                                         $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 406                                         $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 407                                         $this->getQueueKey( 'h-data' ), # KEYS[3]
 408                                         $uuid # ARGV[1]
 409                                 ],
 410                                 3 # number of first argument(s) that are keys
 411                         );
 412
 413                         if ( !$res ) {
 414                                 wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job $uuid." );
 415
 416                                 return false;
 417                         }
 418
 419                         JobQueue::incrStats( 'acks', $this->type );
 420                 } catch ( RedisException $e ) {
 421                         $this->throwRedisException( $conn, $e );
 422                 }
 423
 424                 return true;
 425         }
 426
 427         /**
 428          * @see JobQueue::doDeduplicateRootJob()
 429          * @param IJobSpecification $job
 430          * @return bool
 431          * @throws JobQueueError
 432          * @throws LogicException
 433          */
 434         protected function doDeduplicateRootJob( IJobSpecification $job ) {
 435                 if ( !$job->hasRootJobParams() ) {
 436                         throw new LogicException( "Cannot register root job; missing parameters." );
 437                 }
 438                 $params = $job->getRootJobParams();
 439
 440                 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
 441
 442                 $conn = $this->getConnection();
 443                 try {
 444                         $timestamp = $conn->get( $key ); // current last timestamp of this job
 445                         if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
 446                                 return true; // a newer version of this root job was enqueued
 447                         }
 448
 449                         // Update the timestamp of the last root job started at the location...
 450                         return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
 451                 } catch ( RedisException $e ) {
 452                         $this->throwRedisException( $conn, $e );
 453                 }
 454         }
 455
 456         /**
 457          * @see JobQueue::doIsRootJobOldDuplicate()
 458          * @param Job $job
 459          * @return bool
 460          * @throws JobQueueError
 461          */
 462         protected function doIsRootJobOldDuplicate( Job $job ) {
 463                 if ( !$job->hasRootJobParams() ) {
 464                         return false; // job has no de-deplication info
 465                 }
 466                 $params = $job->getRootJobParams();
 467
 468                 $conn = $this->getConnection();
 469                 try {
 470                         // Get the last time this root job was enqueued
 471                         $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
 472                 } catch ( RedisException $e ) {
 473                         $timestamp = false;
 474                         $this->throwRedisException( $conn, $e );
 475                 }
 476
 477                 // Check if a new root job was started at the location after this one's...
 478                 return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
 479         }
 480
 481         /**
 482          * @see JobQueue::doDelete()
 483          * @return bool
 484          * @throws JobQueueError
 485          */
 486         protected function doDelete() {
 487                 static $props = [ 'l-unclaimed', 'z-claimed', 'z-abandoned',
 488                         'z-delayed', 'h-idBySha1', 'h-sha1ById', 'h-attempts', 'h-data' ];
 489
 490                 $conn = $this->getConnection();
 491                 try {
 492                         $keys = [];
 493                         foreach ( $props as $prop ) {
 494                                 $keys[] = $this->getQueueKey( $prop );
 495                         }
 496
 497                         $ok = ( $conn->delete( $keys ) !== false );
 498                         $conn->sRem( $this->getGlobalKey( 's-queuesWithJobs' ), $this->encodeQueueName() );
 499
 500                         return $ok;
 501                 } catch ( RedisException $e ) {
 502                         $this->throwRedisException( $conn, $e );
 503                 }
 504         }
 505
 506         /**
 507          * @see JobQueue::getAllQueuedJobs()
 508          * @return Iterator
 509          * @throws JobQueueError
 510          */
 511         public function getAllQueuedJobs() {
 512                 $conn = $this->getConnection();
 513                 try {
 514                         $uids = $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 );
 515                 } catch ( RedisException $e ) {
 516                         $this->throwRedisException( $conn, $e );
 517                 }
 518
 519                 return $this->getJobIterator( $conn, $uids );
 520         }
 521
 522         /**
 523          * @see JobQueue::getAllDelayedJobs()
 524          * @return Iterator
 525          * @throws JobQueueError
 526          */
 527         public function getAllDelayedJobs() {
 528                 $conn = $this->getConnection();
 529                 try {
 530                         $uids = $conn->zRange( $this->getQueueKey( 'z-delayed' ), 0, -1 );
 531                 } catch ( RedisException $e ) {
 532                         $this->throwRedisException( $conn, $e );
 533                 }
 534
 535                 return $this->getJobIterator( $conn, $uids );
 536         }
 537
 538         /**
 539          * @see JobQueue::getAllAcquiredJobs()
 540          * @return Iterator
 541          * @throws JobQueueError
 542          */
 543         public function getAllAcquiredJobs() {
 544                 $conn = $this->getConnection();
 545                 try {
 546                         $uids = $conn->zRange( $this->getQueueKey( 'z-claimed' ), 0, -1 );
 547                 } catch ( RedisException $e ) {
 548                         $this->throwRedisException( $conn, $e );
 549                 }
 550
 551                 return $this->getJobIterator( $conn, $uids );
 552         }
 553
 554         /**
 555          * @see JobQueue::getAllAbandonedJobs()
 556          * @return Iterator
 557          * @throws JobQueueError
 558          */
 559         public function getAllAbandonedJobs() {
 560                 $conn = $this->getConnection();
 561                 try {
 562                         $uids = $conn->zRange( $this->getQueueKey( 'z-abandoned' ), 0, -1 );
 563                 } catch ( RedisException $e ) {
 564                         $this->throwRedisException( $conn, $e );
 565                 }
 566
 567                 return $this->getJobIterator( $conn, $uids );
 568         }
 569
 570         /**
 571          * @param RedisConnRef $conn
 572          * @param array $uids List of job UUIDs
 573          * @return MappedIterator
 574          */
 575         protected function getJobIterator( RedisConnRef $conn, array $uids ) {
 576                 return new MappedIterator(
 577                         $uids,
 578                         function ( $uid ) use ( $conn ) {
 579                                 return $this->getJobFromUidInternal( $uid, $conn );
 580                         },
 581                         [ 'accept' => function ( $job ) {
 582                                 return is_object( $job );
 583                         } ]
 584                 );
 585         }
 586
 587         public function getCoalesceLocationInternal() {
 588                 return "RedisServer:" . $this->server;
 589         }
 590
 591         protected function doGetSiblingQueuesWithJobs( array $types ) {
 592                 return array_keys( array_filter( $this->doGetSiblingQueueSizes( $types ) ) );
 593         }
 594
 595         protected function doGetSiblingQueueSizes( array $types ) {
 596                 $sizes = []; // (type => size)
 597                 $types = array_values( $types ); // reindex
 598                 $conn = $this->getConnection();
 599                 try {
 600                         $conn->multi( Redis::PIPELINE );
 601                         foreach ( $types as $type ) {
 602                                 $conn->lSize( $this->getQueueKey( 'l-unclaimed', $type ) );
 603                         }
 604                         $res = $conn->exec();
 605                         if ( is_array( $res ) ) {
 606                                 foreach ( $res as $i => $size ) {
 607                                         $sizes[$types[$i]] = $size;
 608                                 }
 609                         }
 610                 } catch ( RedisException $e ) {
 611                         $this->throwRedisException( $conn, $e );
 612                 }
 613
 614                 return $sizes;
 615         }
 616
 617         /**
 618          * This function should not be called outside JobQueueRedis
 619          *
 620          * @param string $uid
 621          * @param RedisConnRef $conn
 622          * @return Job|bool Returns false if the job does not exist
 623          * @throws JobQueueError
 624          * @throws UnexpectedValueException
 625          */
 626         public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
 627                 try {
 628                         $data = $conn->hGet( $this->getQueueKey( 'h-data' ), $uid );
 629                         if ( $data === false ) {
 630                                 return false; // not found
 631                         }
 632                         $item = $this->unserialize( $data );
 633                         if ( !is_array( $item ) ) { // this shouldn't happen
 634                                 throw new UnexpectedValueException( "Could not find job with ID '$uid'." );
 635                         }
 636                         $title = Title::makeTitle( $item['namespace'], $item['title'] );
 637                         $job = Job::factory( $item['type'], $title, $item['params'] );
 638                         $job->metadata['uuid'] = $item['uuid'];
 639                         $job->metadata['timestamp'] = $item['timestamp'];
 640                         // Add in attempt count for debugging at showJobs.php
 641                         $job->metadata['attempts'] = $conn->hGet( $this->getQueueKey( 'h-attempts' ), $uid );
 642
 643                         return $job;
 644                 } catch ( RedisException $e ) {
 645                         $this->throwRedisException( $conn, $e );
 646                 }
 647         }
 648
 649         /**
 650          * @return array List of (wiki,type) tuples for queues with non-abandoned jobs
 651          * @throws JobQueueConnectionError
 652          * @throws JobQueueError
 653          */
 654         public function getServerQueuesWithJobs() {
 655                 $queues = [];
 656
 657                 $conn = $this->getConnection();
 658                 try {
 659                         $set = $conn->sMembers( $this->getGlobalKey( 's-queuesWithJobs' ) );
 660                         foreach ( $set as $queue ) {
 661                                 $queues[] = $this->decodeQueueName( $queue );
 662                         }
 663                 } catch ( RedisException $e ) {
 664                         $this->throwRedisException( $conn, $e );
 665                 }
 666
 667                 return $queues;
 668         }
 669
 670         /**
 671          * @param IJobSpecification $job
 672          * @return array
 673          */
 674         protected function getNewJobFields( IJobSpecification $job ) {
 675                 return [
 676                         // Fields that describe the nature of the job
 677                         'type' => $job->getType(),
 678                         'namespace' => $job->getTitle()->getNamespace(),
 679                         'title' => $job->getTitle()->getDBkey(),
 680                         'params' => $job->getParams(),
 681                         // Some jobs cannot run until a "release timestamp"
 682                         'rtimestamp' => $job->getReleaseTimestamp() ?: 0,
 683                         // Additional job metadata
 684                         'uuid' => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 685                         'sha1' => $job->ignoreDuplicates()
 686                                 ? Wikimedia\base_convert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 687                                 : '',
 688                         'timestamp' => time() // UNIX timestamp
 689                 ];
 690         }
 691
 692         /**
 693          * @param array $fields
 694          * @return Job|bool
 695          */
 696         protected function getJobFromFields( array $fields ) {
 697                 $title = Title::makeTitle( $fields['namespace'], $fields['title'] );
 698                 $job = Job::factory( $fields['type'], $title, $fields['params'] );
 699                 $job->metadata['uuid'] = $fields['uuid'];
 700                 $job->metadata['timestamp'] = $fields['timestamp'];
 701
 702                 return $job;
 703         }
 704
 705         /**
 706          * @param array $fields
 707          * @return string Serialized and possibly compressed version of $fields
 708          */
 709         protected function serialize( array $fields ) {
 710                 $blob = serialize( $fields );
 711                 if ( $this->compression === 'gzip'
 712                         && strlen( $blob ) >= 1024
 713                         && function_exists( 'gzdeflate' )
 714                 ) {
 715                         $object = (object)[ 'blob' => gzdeflate( $blob ), 'enc' => 'gzip' ];
 716                         $blobz = serialize( $object );
 717
 718                         return ( strlen( $blobz ) < strlen( $blob ) ) ? $blobz : $blob;
 719                 } else {
 720                         return $blob;
 721                 }
 722         }
 723
 724         /**
 725          * @param string $blob
 726          * @return array|bool Unserialized version of $blob or false
 727          */
 728         protected function unserialize( $blob ) {
 729                 $fields = unserialize( $blob );
 730                 if ( is_object( $fields ) ) {
 731                         if ( $fields->enc === 'gzip' && function_exists( 'gzinflate' ) ) {
 732                                 $fields = unserialize( gzinflate( $fields->blob ) );
 733                         } else {
 734                                 $fields = false;
 735                         }
 736                 }
 737
 738                 return is_array( $fields ) ? $fields : false;
 739         }
 740
 741         /**
 742          * Get a connection to the server that handles all sub-queues for this queue
 743          *
 744          * @return RedisConnRef
 745          * @throws JobQueueConnectionError
 746          */
 747         protected function getConnection() {
 748                 $conn = $this->redisPool->getConnection( $this->server );
 749                 if ( !$conn ) {
 750                         throw new JobQueueConnectionError(
 751                                 "Unable to connect to redis server {$this->server}." );
 752                 }
 753
 754                 return $conn;
 755         }
 756
 757         /**
 758          * @param RedisConnRef $conn
 759          * @param RedisException $e
 760          * @throws JobQueueError
 761          */
 762         protected function throwRedisException( RedisConnRef $conn, $e ) {
 763                 $this->redisPool->handleError( $conn, $e );
 764                 throw new JobQueueError( "Redis server error: {$e->getMessage()}\n" );
 765         }
 766
 767         /**
 768          * @return string JSON
 769          */
 770         private function encodeQueueName() {
 771                 return json_encode( [ $this->type, $this->wiki ] );
 772         }
 773
 774         /**
 775          * @param string $name JSON
 776          * @return array (type, wiki)
 777          */
 778         private function decodeQueueName( $name ) {
 779                 return json_decode( $name );
 780         }
 781
 782         /**
 783          * @param string $name
 784          * @return string
 785          */
 786         private function getGlobalKey( $name ) {
 787                 $parts = [ 'global', 'jobqueue', $name ];
 788                 foreach ( $parts as $part ) {
 789                     if ( !preg_match( '/[a-zA-Z0-9_-]+/', $part ) ) {
 790                         throw new InvalidArgumentException( "Key part characters are out of range." );
 791                     }
 792                 }
 793
 794                 return implode( ':', $parts );
 795         }
 796
 797         /**
 798          * @param string $prop
 799          * @param string|null $type Override this for sibling queues
 800          * @return string
 801          */
 802         private function getQueueKey( $prop, $type = null ) {
 803                 $type = is_string( $type ) ? $type : $this->type;
 804                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 805                 $keyspace = $prefix ? "$db-$prefix" : $db;
 806
 807                 $parts = [ $keyspace, 'jobqueue', $type, $prop ];
 808
 809                 // Parts are typically ASCII, but encode for sanity to escape ":"
 810                 return implode( ':', array_map( 'rawurlencode', $parts ) );
 811         }
 812 }