includes/jobqueue/jobs/ClearUserWatchlistJob.php

   1 <?php
   2
   3 use MediaWiki\MediaWikiServices;
   4 use MediaWiki\User\UserIdentity;
   5
   6 /**
   7  * Job to clear a users watchlist in batches.
   8  *
   9  * @author Addshore
  10  *
  11  * @ingroup JobQueue
  12  * @since 1.31
  13  */
  14 class ClearUserWatchlistJob extends Job implements GenericParameterJob {
  15         /**
  16          * @param array $params
  17          *  - userId,         The ID for the user whose watchlist is being cleared.
  18          *  - maxWatchlistId, The maximum wl_id at the time the job was first created,
  19          */
  20         public function __construct( array $params ) {
  21                 parent::__construct( 'clearUserWatchlist', $params );
  22
  23                 $this->removeDuplicates = true;
  24         }
  25
  26         /**
  27          * @param UserIdentity $user User to clear the watchlist for.
  28          * @param int $maxWatchlistId The maximum wl_id at the time the job was first created.
  29          *
  30          * @return ClearUserWatchlistJob
  31          */
  32         public static function newForUser( UserIdentity $user, $maxWatchlistId ) {
  33                 return new self( [ 'userId' => $user->getId(), 'maxWatchlistId' => $maxWatchlistId ] );
  34         }
  35
  36         public function run() {
  37                 global $wgUpdateRowsPerQuery;
  38                 $userId = $this->params['userId'];
  39                 $maxWatchlistId = $this->params['maxWatchlistId'];
  40                 $batchSize = $wgUpdateRowsPerQuery;
  41
  42                 $loadBalancer = MediaWikiServices::getInstance()->getDBLoadBalancer();
  43                 $dbw = $loadBalancer->getConnection( DB_MASTER );
  44                 $dbr = $loadBalancer->getConnection( DB_REPLICA, [ 'watchlist' ] );
  45
  46                 // Wait before lock to try to reduce time waiting in the lock.
  47                 if ( !$loadBalancer->safeWaitForMasterPos( $dbr ) ) {
  48                         $this->setLastError( 'Timed out waiting for replica to catch up before lock' );
  49                         return false;
  50                 }
  51
  52                 // Use a named lock so that jobs for this user see each others' changes
  53                 $lockKey = "ClearUserWatchlistJob:$userId";
  54                 $scopedLock = $dbw->getScopedLockAndFlush( $lockKey, __METHOD__, 10 );
  55                 if ( !$scopedLock ) {
  56                         $this->setLastError( "Could not acquire lock '$lockKey'" );
  57                         return false;
  58                 }
  59
  60                 if ( !$loadBalancer->safeWaitForMasterPos( $dbr ) ) {
  61                         $this->setLastError( 'Timed out waiting for replica to catch up within lock' );
  62                         return false;
  63                 }
  64
  65                 // Clear any stale REPEATABLE-READ snapshot
  66                 $dbr->flushSnapshot( __METHOD__ );
  67
  68                 $watchlistIds = $dbr->selectFieldValues(
  69                         'watchlist',
  70                         'wl_id',
  71                         [
  72                                 'wl_user' => $userId,
  73                                 'wl_id <= ' . $maxWatchlistId
  74                         ],
  75                         __METHOD__,
  76                         [
  77                                 'ORDER BY' => 'wl_id ASC',
  78                                 'LIMIT' => $batchSize,
  79                         ]
  80                 );
  81
  82                 if ( count( $watchlistIds ) == 0 ) {
  83                         return true;
  84                 }
  85
  86                 $dbw->delete( 'watchlist', [ 'wl_id' => $watchlistIds ], __METHOD__ );
  87
  88                 // Commit changes and remove lock before inserting next job.
  89                 $lbf = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
  90                 $lbf->commitMasterChanges( __METHOD__ );
  91                 unset( $scopedLock );
  92
  93                 if ( count( $watchlistIds ) === (int)$batchSize ) {
  94                         // Until we get less results than the limit, recursively push
  95                         // the same job again.
  96                         JobQueueGroup::singleton()->push( new self( $this->getParams() ) );
  97                 }
  98
  99                 return true;
 100         }
 101
 102         public function getDeduplicationInfo() {
 103                 $info = parent::getDeduplicationInfo();
 104                 // This job never has a namespace or title so we can't use it for deduplication
 105                 unset( $info['namespace'] );
 106                 unset( $info['title'] );
 107                 return $info;
 108         }
 109
 110 }