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 use Psr\Log\LoggerInterface;
  24
  25 /**
  26  * Class to handle job queues stored in Redis
  27  *
  28  * This is a faster and less resource-intensive job queue than JobQueueDB.
  29  * All data for a queue using this class is placed into one redis server.
  30  * The mediawiki/services/jobrunner background service must be set up and running.
  31  *
  32  * There are eight main redis keys (per queue) used to track jobs:
  33  *   - l-unclaimed  : A list of job IDs used for ready unclaimed jobs
  34  *   - z-claimed    : A sorted set of (job ID, UNIX timestamp as score) used for job retries
  35  *   - z-abandoned  : A sorted set of (job ID, UNIX timestamp as score) used for broken jobs
  36  *   - z-delayed    : A sorted set of (job ID, UNIX timestamp as score) used for delayed jobs
  37  *   - h-idBySha1   : A hash of (SHA1 => job ID) for unclaimed jobs used for de-duplication
  38  *   - h-sha1ById   : A hash of (job ID => SHA1) for unclaimed jobs used for de-duplication
  39  *   - h-attempts   : A hash of (job ID => attempt count) used for job claiming/retries
  40  *   - h-data       : A hash of (job ID => serialized blobs) for job storage
  41  * A job ID can be in only one of z-delayed, l-unclaimed, z-claimed, and z-abandoned.
  42  * If an ID appears in any of those lists, it should have a h-data entry for its ID.
  43  * If a job has a SHA1 de-duplication value and its ID is in l-unclaimed or z-delayed, then
  44  * there should be no other such jobs with that SHA1. Every h-idBySha1 entry has an h-sha1ById
  45  * entry and every h-sha1ById must refer to an ID that is l-unclaimed. If a job has its
  46  * ID in z-claimed or z-abandoned, then it must also have an h-attempts entry for its ID.
  47  *
  48  * The following keys are used to track queue states:
  49  *   - s-queuesWithJobs : A set of all queues with non-abandoned jobs
  50  *
  51  * The background service takes care of undelaying, recycling, and pruning jobs as well as
  52  * removing s-queuesWithJobs entries as queues empty.
  53  *
  54  * Additionally, "rootjob:* keys track "root jobs" used for additional de-duplication.
  55  * Aside from root job keys, all keys have no expiry, and are only removed when jobs are run.
  56  * All the keys are prefixed with the relevant wiki ID information.
  57  *
  58  * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic operations.
  59  * Additionally, it should be noted that redis has different persistence modes, such
  60  * as rdb snapshots, journaling, and no persistence. Appropriate configuration should be
  61  * made on the servers based on what queues are using it and what tolerance they have.
  62  *
  63  * @ingroup JobQueue
  64  * @ingroup Redis
  65  * @since 1.22
  66  */
  67 class JobQueueRedis extends JobQueue {
  68         /** @var RedisConnectionPool */
  69         protected $redisPool;
  70         /** @var LoggerInterface */
  71         protected $logger;
  72
  73         /** @var string Server address */
  74         protected $server;
  75         /** @var string Compression method to use */
  76         protected $compression;
  77
  78         const MAX_PUSH_SIZE = 25; // avoid tying up the server
  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                 $this->logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'redis' );
 105         }
 106
 107         protected function supportedOrders() {
 108                 return [ 'timestamp', 'fifo' ];
 109         }
 110
 111         protected function optimalOrder() {
 112                 return 'fifo';
 113         }
 114
 115         protected function supportsDelayedJobs() {
 116                 return true;
 117         }
 118
 119         /**
 120          * @see JobQueue::doIsEmpty()
 121          * @return bool
 122          * @throws JobQueueError
 123          */
 124         protected function doIsEmpty() {
 125                 return $this->doGetSize() == 0;
 126         }
 127
 128         /**
 129          * @see JobQueue::doGetSize()
 130          * @return int
 131          * @throws JobQueueError
 132          */
 133         protected function doGetSize() {
 134                 $conn = $this->getConnection();
 135                 try {
 136                         return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
 137                 } catch ( RedisException $e ) {
 138                         $this->throwRedisException( $conn, $e );
 139                 }
 140         }
 141
 142         /**
 143          * @see JobQueue::doGetAcquiredCount()
 144          * @return int
 145          * @throws JobQueueError
 146          */
 147         protected function doGetAcquiredCount() {
 148                 $conn = $this->getConnection();
 149                 try {
 150                         $conn->multi( Redis::PIPELINE );
 151                         $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
 152                         $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 153
 154                         return array_sum( $conn->exec() );
 155                 } catch ( RedisException $e ) {
 156                         $this->throwRedisException( $conn, $e );
 157                 }
 158         }
 159
 160         /**
 161          * @see JobQueue::doGetDelayedCount()
 162          * @return int
 163          * @throws JobQueueError
 164          */
 165         protected function doGetDelayedCount() {
 166                 $conn = $this->getConnection();
 167                 try {
 168                         return $conn->zSize( $this->getQueueKey( 'z-delayed' ) );
 169                 } catch ( RedisException $e ) {
 170                         $this->throwRedisException( $conn, $e );
 171                 }
 172         }
 173
 174         /**
 175          * @see JobQueue::doGetAbandonedCount()
 176          * @return int
 177          * @throws JobQueueError
 178          */
 179         protected function doGetAbandonedCount() {
 180                 $conn = $this->getConnection();
 181                 try {
 182                         return $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 183                 } catch ( RedisException $e ) {
 184                         $this->throwRedisException( $conn, $e );
 185                 }
 186         }
 187
 188         /**
 189          * @see JobQueue::doBatchPush()
 190          * @param IJobSpecification[] $jobs
 191          * @param int $flags
 192          * @return void
 193          * @throws JobQueueError
 194          */
 195         protected function doBatchPush( array $jobs, $flags ) {
 196                 // Convert the jobs into field maps (de-duplicated against each other)
 197                 $items = []; // (job ID => job fields map)
 198                 foreach ( $jobs as $job ) {
 199                         $item = $this->getNewJobFields( $job );
 200                         if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
 201                                 $items[$item['sha1']] = $item;
 202                         } else {
 203                                 $items[$item['uuid']] = $item;
 204                         }
 205                 }
 206
 207                 if ( !count( $items ) ) {
 208                         return; // nothing to do
 209                 }
 210
 211                 $conn = $this->getConnection();
 212                 try {
 213                         // Actually push the non-duplicate jobs into the queue...
 214                         if ( $flags & self::QOS_ATOMIC ) {
 215                                 $batches = [ $items ]; // all or nothing
 216                         } else {
 217                                 $batches = array_chunk( $items, self::MAX_PUSH_SIZE );
 218                         }
 219                         $failed = 0;
 220                         $pushed = 0;
 221                         foreach ( $batches as $itemBatch ) {
 222                                 $added = $this->pushBlobs( $conn, $itemBatch );
 223                                 if ( is_int( $added ) ) {
 224                                         $pushed += $added;
 225                                 } else {
 226                                         $failed += count( $itemBatch );
 227                                 }
 228                         }
 229                         JobQueue::incrStats( 'inserts', $this->type, count( $items ) );
 230                         JobQueue::incrStats( 'inserts_actual', $this->type, $pushed );
 231                         JobQueue::incrStats( 'dupe_inserts', $this->type,
 232                                 count( $items ) - $failed - $pushed );
 233                         if ( $failed > 0 ) {
 234                                 $err = "Could not insert {$failed} {$this->type} job(s).";
 235                                 wfDebugLog( 'JobQueueRedis', $err );
 236                                 throw new RedisException( $err );
 237                         }
 238                 } catch ( RedisException $e ) {
 239                         $this->throwRedisException( $conn, $e );
 240                 }
 241         }
 242
 243         /**
 244          * @param RedisConnRef $conn
 245          * @param array $items List of results from JobQueueRedis::getNewJobFields()
 246          * @return int Number of jobs inserted (duplicates are ignored)
 247          * @throws RedisException
 248          */
 249         protected function pushBlobs( RedisConnRef $conn, array $items ) {
 250                 $args = [ $this->encodeQueueName() ];
 251                 // Next args come in 4s ([id, sha1, rtime, blob [, id, sha1, rtime, blob ... ] ] )
 252                 foreach ( $items as $item ) {
 253                         $args[] = (string)$item['uuid'];
 254                         $args[] = (string)$item['sha1'];
 255                         $args[] = (string)$item['rtimestamp'];
 256                         $args[] = (string)$this->serialize( $item );
 257                 }
 258                 static $script =
 259                 /** @lang Lua */
 260 <<<LUA
 261                 local kUnclaimed, kSha1ById, kIdBySha1, kDelayed, kData, kQwJobs = unpack(KEYS)
 262                 -- First argument is the queue ID
 263                 local queueId = ARGV[1]
 264                 -- Next arguments all come in 4s (one per job)
 265                 local variadicArgCount = #ARGV - 1
 266                 if variadicArgCount % 4 ~= 0 then
 267                         return redis.error_reply('Unmatched arguments')
 268                 end
 269                 -- Insert each job into this queue as needed
 270                 local pushed = 0
 271                 for i = 2,#ARGV,4 do
 272                         local id,sha1,rtimestamp,blob = ARGV[i],ARGV[i+1],ARGV[i+2],ARGV[i+3]
 273                         if sha1 == '' or redis.call('hExists',kIdBySha1,sha1) == 0 then
 274                                 if 1*rtimestamp > 0 then
 275                                         -- Insert into delayed queue (release time as score)
 276                                         redis.call('zAdd',kDelayed,rtimestamp,id)
 277                                 else
 278                                         -- Insert into unclaimed queue
 279                                         redis.call('lPush',kUnclaimed,id)
 280                                 end
 281                                 if sha1 ~= '' then
 282                                         redis.call('hSet',kSha1ById,id,sha1)
 283                                         redis.call('hSet',kIdBySha1,sha1,id)
 284                                 end
 285                                 redis.call('hSet',kData,id,blob)
 286                                 pushed = pushed + 1
 287                         end
 288                 end
 289                 -- Mark this queue as having jobs
 290                 redis.call('sAdd',kQwJobs,queueId)
 291                 return pushed
 292 LUA;
 293                 return $conn->luaEval( $script,
 294                         array_merge(
 295                                 [
 296                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 297                                         $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 298                                         $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 299                                         $this->getQueueKey( 'z-delayed' ), # KEYS[4]
 300                                         $this->getQueueKey( 'h-data' ), # KEYS[5]
 301                                         $this->getGlobalKey( 's-queuesWithJobs' ), # KEYS[6]
 302                                 ],
 303                                 $args
 304                         ),
 305                         6 # number of first argument(s) that are keys
 306                 );
 307         }
 308
 309         /**
 310          * @see JobQueue::doPop()
 311          * @return Job|bool
 312          * @throws JobQueueError
 313          */
 314         protected function doPop() {
 315                 $job = false;
 316
 317                 $conn = $this->getConnection();
 318                 try {
 319                         do {
 320                                 $blob = $this->popAndAcquireBlob( $conn );
 321                                 if ( !is_string( $blob ) ) {
 322                                         break; // no jobs; nothing to do
 323                                 }
 324
 325                                 JobQueue::incrStats( 'pops', $this->type );
 326                                 $item = $this->unserialize( $blob );
 327                                 if ( $item === false ) {
 328                                         wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
 329                                         continue;
 330                                 }
 331
 332                                 // If $item is invalid, the runner loop recyling will cleanup as needed
 333                                 $job = $this->getJobFromFields( $item ); // may be false
 334                         } while ( !$job ); // job may be false if invalid
 335                 } catch ( RedisException $e ) {
 336                         $this->throwRedisException( $conn, $e );
 337                 }
 338
 339                 return $job;
 340         }
 341
 342         /**
 343          * @param RedisConnRef $conn
 344          * @return array Serialized string or false
 345          * @throws RedisException
 346          */
 347         protected function popAndAcquireBlob( RedisConnRef $conn ) {
 348                 static $script =
 349                 /** @lang Lua */
 350 <<<LUA
 351                 local kUnclaimed, kSha1ById, kIdBySha1, kClaimed, kAttempts, kData = unpack(KEYS)
 352                 local rTime = unpack(ARGV)
 353                 -- Pop an item off the queue
 354                 local id = redis.call('rPop',kUnclaimed)
 355                 if not id then
 356                         return false
 357                 end
 358                 -- Allow new duplicates of this job
 359                 local sha1 = redis.call('hGet',kSha1ById,id)
 360                 if sha1 then redis.call('hDel',kIdBySha1,sha1) end
 361                 redis.call('hDel',kSha1ById,id)
 362                 -- Mark the jobs as claimed and return it
 363                 redis.call('zAdd',kClaimed,rTime,id)
 364                 redis.call('hIncrBy',kAttempts,id,1)
 365                 return redis.call('hGet',kData,id)
 366 LUA;
 367                 return $conn->luaEval( $script,
 368                         [
 369                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 370                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 371                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 372                                 $this->getQueueKey( 'z-claimed' ), # KEYS[4]
 373                                 $this->getQueueKey( 'h-attempts' ), # KEYS[5]
 374                                 $this->getQueueKey( 'h-data' ), # KEYS[6]
 375                                 time(), # ARGV[1] (injected to be replication-safe)
 376                         ],
 377                         6 # number of first argument(s) that are keys
 378                 );
 379         }
 380
 381         /**
 382          * @see JobQueue::doAck()
 383          * @param Job $job
 384          * @return Job|bool
 385          * @throws UnexpectedValueException
 386          * @throws JobQueueError
 387          */
 388         protected function doAck( Job $job ) {
 389                 if ( !isset( $job->metadata['uuid'] ) ) {
 390                         throw new UnexpectedValueException( "Job of type '{$job->getType()}' has no UUID." );
 391                 }
 392
 393                 $uuid = $job->metadata['uuid'];
 394                 $conn = $this->getConnection();
 395                 try {
 396                         static $script =
 397                         /** @lang Lua */
 398 <<<LUA
 399                         local kClaimed, kAttempts, kData = unpack(KEYS)
 400                         local id = unpack(ARGV)
 401                         -- Unmark the job as claimed
 402                         local removed = redis.call('zRem',kClaimed,id)
 403                         -- Check if the job was recycled
 404                         if removed == 0 then
 405                                 return 0
 406                         end
 407                         -- Delete the retry data
 408                         redis.call('hDel',kAttempts,id)
 409                         -- Delete the job data itself
 410                         return redis.call('hDel',kData,id)
 411 LUA;
 412                         $res = $conn->luaEval( $script,
 413                                 [
 414                                         $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 415                                         $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 416                                         $this->getQueueKey( 'h-data' ), # KEYS[3]
 417                                         $uuid # ARGV[1]
 418                                 ],
 419                                 3 # number of first argument(s) that are keys
 420                         );
 421
 422                         if ( !$res ) {
 423                                 wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job $uuid." );
 424
 425                                 return false;
 426                         }
 427
 428                         JobQueue::incrStats( 'acks', $this->type );
 429                 } catch ( RedisException $e ) {
 430                         $this->throwRedisException( $conn, $e );
 431                 }
 432
 433                 return true;
 434         }
 435
 436         /**
 437          * @see JobQueue::doDeduplicateRootJob()
 438          * @param IJobSpecification $job
 439          * @return bool
 440          * @throws JobQueueError
 441          * @throws LogicException
 442          */
 443         protected function doDeduplicateRootJob( IJobSpecification $job ) {
 444                 if ( !$job->hasRootJobParams() ) {
 445                         throw new LogicException( "Cannot register root job; missing parameters." );
 446                 }
 447                 $params = $job->getRootJobParams();
 448
 449                 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
 450
 451                 $conn = $this->getConnection();
 452                 try {
 453                         $timestamp = $conn->get( $key ); // current last timestamp of this job
 454                         if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
 455                                 return true; // a newer version of this root job was enqueued
 456                         }
 457
 458                         // Update the timestamp of the last root job started at the location...
 459                         return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
 460                 } catch ( RedisException $e ) {
 461                         $this->throwRedisException( $conn, $e );
 462                 }
 463         }
 464
 465         /**
 466          * @see JobQueue::doIsRootJobOldDuplicate()
 467          * @param Job $job
 468          * @return bool
 469          * @throws JobQueueError
 470          */
 471         protected function doIsRootJobOldDuplicate( Job $job ) {
 472                 if ( !$job->hasRootJobParams() ) {
 473                         return false; // job has no de-deplication info
 474                 }
 475                 $params = $job->getRootJobParams();
 476
 477                 $conn = $this->getConnection();
 478                 try {
 479                         // Get the last time this root job was enqueued
 480                         $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
 481                 } catch ( RedisException $e ) {
 482                         $timestamp = false;
 483                         $this->throwRedisException( $conn, $e );
 484                 }
 485
 486                 // Check if a new root job was started at the location after this one's...
 487                 return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
 488         }
 489
 490         /**
 491          * @see JobQueue::doDelete()
 492          * @return bool
 493          * @throws JobQueueError
 494          */
 495         protected function doDelete() {
 496                 static $props = [ 'l-unclaimed', 'z-claimed', 'z-abandoned',
 497                         'z-delayed', 'h-idBySha1', 'h-sha1ById', 'h-attempts', 'h-data' ];
 498
 499                 $conn = $this->getConnection();
 500                 try {
 501                         $keys = [];
 502                         foreach ( $props as $prop ) {
 503                                 $keys[] = $this->getQueueKey( $prop );
 504                         }
 505
 506                         $ok = ( $conn->delete( $keys ) !== false );
 507                         $conn->sRem( $this->getGlobalKey( 's-queuesWithJobs' ), $this->encodeQueueName() );
 508
 509                         return $ok;
 510                 } catch ( RedisException $e ) {
 511                         $this->throwRedisException( $conn, $e );
 512                 }
 513         }
 514
 515         /**
 516          * @see JobQueue::getAllQueuedJobs()
 517          * @return Iterator
 518          * @throws JobQueueError
 519          */
 520         public function getAllQueuedJobs() {
 521                 $conn = $this->getConnection();
 522                 try {
 523                         $uids = $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 );
 524                 } catch ( RedisException $e ) {
 525                         $this->throwRedisException( $conn, $e );
 526                 }
 527
 528                 return $this->getJobIterator( $conn, $uids );
 529         }
 530
 531         /**
 532          * @see JobQueue::getAllDelayedJobs()
 533          * @return Iterator
 534          * @throws JobQueueError
 535          */
 536         public function getAllDelayedJobs() {
 537                 $conn = $this->getConnection();
 538                 try {
 539                         $uids = $conn->zRange( $this->getQueueKey( 'z-delayed' ), 0, -1 );
 540                 } catch ( RedisException $e ) {
 541                         $this->throwRedisException( $conn, $e );
 542                 }
 543
 544                 return $this->getJobIterator( $conn, $uids );
 545         }
 546
 547         /**
 548          * @see JobQueue::getAllAcquiredJobs()
 549          * @return Iterator
 550          * @throws JobQueueError
 551          */
 552         public function getAllAcquiredJobs() {
 553                 $conn = $this->getConnection();
 554                 try {
 555                         $uids = $conn->zRange( $this->getQueueKey( 'z-claimed' ), 0, -1 );
 556                 } catch ( RedisException $e ) {
 557                         $this->throwRedisException( $conn, $e );
 558                 }
 559
 560                 return $this->getJobIterator( $conn, $uids );
 561         }
 562
 563         /**
 564          * @see JobQueue::getAllAbandonedJobs()
 565          * @return Iterator
 566          * @throws JobQueueError
 567          */
 568         public function getAllAbandonedJobs() {
 569                 $conn = $this->getConnection();
 570                 try {
 571                         $uids = $conn->zRange( $this->getQueueKey( 'z-abandoned' ), 0, -1 );
 572                 } catch ( RedisException $e ) {
 573                         $this->throwRedisException( $conn, $e );
 574                 }
 575
 576                 return $this->getJobIterator( $conn, $uids );
 577         }
 578
 579         /**
 580          * @param RedisConnRef $conn
 581          * @param array $uids List of job UUIDs
 582          * @return MappedIterator
 583          */
 584         protected function getJobIterator( RedisConnRef $conn, array $uids ) {
 585                 return new MappedIterator(
 586                         $uids,
 587                         function ( $uid ) use ( $conn ) {
 588                                 return $this->getJobFromUidInternal( $uid, $conn );
 589                         },
 590                         [ 'accept' => function ( $job ) {
 591                                 return is_object( $job );
 592                         } ]
 593                 );
 594         }
 595
 596         public function getCoalesceLocationInternal() {
 597                 return "RedisServer:" . $this->server;
 598         }
 599
 600         protected function doGetSiblingQueuesWithJobs( array $types ) {
 601                 return array_keys( array_filter( $this->doGetSiblingQueueSizes( $types ) ) );
 602         }
 603
 604         protected function doGetSiblingQueueSizes( array $types ) {
 605                 $sizes = []; // (type => size)
 606                 $types = array_values( $types ); // reindex
 607                 $conn = $this->getConnection();
 608                 try {
 609                         $conn->multi( Redis::PIPELINE );
 610                         foreach ( $types as $type ) {
 611                                 $conn->lSize( $this->getQueueKey( 'l-unclaimed', $type ) );
 612                         }
 613                         $res = $conn->exec();
 614                         if ( is_array( $res ) ) {
 615                                 foreach ( $res as $i => $size ) {
 616                                         $sizes[$types[$i]] = $size;
 617                                 }
 618                         }
 619                 } catch ( RedisException $e ) {
 620                         $this->throwRedisException( $conn, $e );
 621                 }
 622
 623                 return $sizes;
 624         }
 625
 626         /**
 627          * This function should not be called outside JobQueueRedis
 628          *
 629          * @param string $uid
 630          * @param RedisConnRef $conn
 631          * @return Job|bool Returns false if the job does not exist
 632          * @throws JobQueueError
 633          * @throws UnexpectedValueException
 634          */
 635         public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
 636                 try {
 637                         $data = $conn->hGet( $this->getQueueKey( 'h-data' ), $uid );
 638                         if ( $data === false ) {
 639                                 return false; // not found
 640                         }
 641                         $item = $this->unserialize( $data );
 642                         if ( !is_array( $item ) ) { // this shouldn't happen
 643                                 throw new UnexpectedValueException( "Could not find job with ID '$uid'." );
 644                         }
 645                         $title = Title::makeTitle( $item['namespace'], $item['title'] );
 646                         $job = Job::factory( $item['type'], $title, $item['params'] );
 647                         $job->metadata['uuid'] = $item['uuid'];
 648                         $job->metadata['timestamp'] = $item['timestamp'];
 649                         // Add in attempt count for debugging at showJobs.php
 650                         $job->metadata['attempts'] = $conn->hGet( $this->getQueueKey( 'h-attempts' ), $uid );
 651
 652                         return $job;
 653                 } catch ( RedisException $e ) {
 654                         $this->throwRedisException( $conn, $e );
 655                 }
 656         }
 657
 658         /**
 659          * @return array List of (wiki,type) tuples for queues with non-abandoned jobs
 660          * @throws JobQueueConnectionError
 661          * @throws JobQueueError
 662          */
 663         public function getServerQueuesWithJobs() {
 664                 $queues = [];
 665
 666                 $conn = $this->getConnection();
 667                 try {
 668                         $set = $conn->sMembers( $this->getGlobalKey( 's-queuesWithJobs' ) );
 669                         foreach ( $set as $queue ) {
 670                                 $queues[] = $this->decodeQueueName( $queue );
 671                         }
 672                 } catch ( RedisException $e ) {
 673                         $this->throwRedisException( $conn, $e );
 674                 }
 675
 676                 return $queues;
 677         }
 678
 679         /**
 680          * @param IJobSpecification $job
 681          * @return array
 682          */
 683         protected function getNewJobFields( IJobSpecification $job ) {
 684                 return [
 685                         // Fields that describe the nature of the job
 686                         'type' => $job->getType(),
 687                         'namespace' => $job->getTitle()->getNamespace(),
 688                         'title' => $job->getTitle()->getDBkey(),
 689                         'params' => $job->getParams(),
 690                         // Some jobs cannot run until a "release timestamp"
 691                         'rtimestamp' => $job->getReleaseTimestamp() ?: 0,
 692                         // Additional job metadata
 693                         'uuid' => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 694                         'sha1' => $job->ignoreDuplicates()
 695                                 ? Wikimedia\base_convert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 696                                 : '',
 697                         'timestamp' => time() // UNIX timestamp
 698                 ];
 699         }
 700
 701         /**
 702          * @param array $fields
 703          * @return Job|bool
 704          */
 705         protected function getJobFromFields( array $fields ) {
 706                 $title = Title::makeTitle( $fields['namespace'], $fields['title'] );
 707                 $job = Job::factory( $fields['type'], $title, $fields['params'] );
 708                 $job->metadata['uuid'] = $fields['uuid'];
 709                 $job->metadata['timestamp'] = $fields['timestamp'];
 710
 711                 return $job;
 712         }
 713
 714         /**
 715          * @param array $fields
 716          * @return string Serialized and possibly compressed version of $fields
 717          */
 718         protected function serialize( array $fields ) {
 719                 $blob = serialize( $fields );
 720                 if ( $this->compression === 'gzip'
 721                         && strlen( $blob ) >= 1024
 722                         && function_exists( 'gzdeflate' )
 723                 ) {
 724                         $object = (object)[ 'blob' => gzdeflate( $blob ), 'enc' => 'gzip' ];
 725                         $blobz = serialize( $object );
 726
 727                         return ( strlen( $blobz ) < strlen( $blob ) ) ? $blobz : $blob;
 728                 } else {
 729                         return $blob;
 730                 }
 731         }
 732
 733         /**
 734          * @param string $blob
 735          * @return array|bool Unserialized version of $blob or false
 736          */
 737         protected function unserialize( $blob ) {
 738                 $fields = unserialize( $blob );
 739                 if ( is_object( $fields ) ) {
 740                         if ( $fields->enc === 'gzip' && function_exists( 'gzinflate' ) ) {
 741                                 $fields = unserialize( gzinflate( $fields->blob ) );
 742                         } else {
 743                                 $fields = false;
 744                         }
 745                 }
 746
 747                 return is_array( $fields ) ? $fields : false;
 748         }
 749
 750         /**
 751          * Get a connection to the server that handles all sub-queues for this queue
 752          *
 753          * @return RedisConnRef
 754          * @throws JobQueueConnectionError
 755          */
 756         protected function getConnection() {
 757                 $conn = $this->redisPool->getConnection( $this->server, $this->logger );
 758                 if ( !$conn ) {
 759                         throw new JobQueueConnectionError(
 760                                 "Unable to connect to redis server {$this->server}." );
 761                 }
 762
 763                 return $conn;
 764         }
 765
 766         /**
 767          * @param RedisConnRef $conn
 768          * @param RedisException $e
 769          * @throws JobQueueError
 770          */
 771         protected function throwRedisException( RedisConnRef $conn, $e ) {
 772                 $this->redisPool->handleError( $conn, $e );
 773                 throw new JobQueueError( "Redis server error: {$e->getMessage()}\n" );
 774         }
 775
 776         /**
 777          * @return string JSON
 778          */
 779         private function encodeQueueName() {
 780                 return json_encode( [ $this->type, $this->wiki ] );
 781         }
 782
 783         /**
 784          * @param string $name JSON
 785          * @return array (type, wiki)
 786          */
 787         private function decodeQueueName( $name ) {
 788                 return json_decode( $name );
 789         }
 790
 791         /**
 792          * @param string $name
 793          * @return string
 794          */
 795         private function getGlobalKey( $name ) {
 796                 $parts = [ 'global', 'jobqueue', $name ];
 797                 foreach ( $parts as $part ) {
 798                         if ( !preg_match( '/[a-zA-Z0-9_-]+/', $part ) ) {
 799                                 throw new InvalidArgumentException( "Key part characters are out of range." );
 800                         }
 801                 }
 802
 803                 return implode( ':', $parts );
 804         }
 805
 806         /**
 807          * @param string $prop
 808          * @param string|null $type Override this for sibling queues
 809          * @return string
 810          */
 811         private function getQueueKey( $prop, $type = null ) {
 812                 $type = is_string( $type ) ? $type : $this->type;
 813                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 814                 $keyspace = $prefix ? "$db-$prefix" : $db;
 815
 816                 $parts = [ $keyspace, 'jobqueue', $type, $prop ];
 817
 818                 // Parts are typically ASCII, but encode for sanity to escape ":"
 819                 return implode( ':', array_map( 'rawurlencode', $parts ) );
 820         }
 821 }