includes/deferred/LinksDeletionUpdate.php

   1 <?php
   2 /**
   3  * Updater for link tracking tables after a page edit.
   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  */
  22 use MediaWiki\MediaWikiServices;
  23 use Wikimedia\ScopedCallback;
  24
  25 /**
  26  * Update object handling the cleanup of links tables after a page was deleted.
  27  */
  28 class LinksDeletionUpdate extends LinksUpdate implements EnqueueableDataUpdate {
  29         /** @var WikiPage */
  30         protected $page;
  31         /** @var string */
  32         protected $timestamp;
  33
  34         /**
  35          * @param WikiPage $page Page we are updating
  36          * @param int|null $pageId ID of the page we are updating [optional]
  37          * @param string|null $timestamp TS_MW timestamp of deletion
  38          * @throws MWException
  39          */
  40         function __construct( WikiPage $page, $pageId = null, $timestamp = null ) {
  41                 $this->page = $page;
  42                 if ( $pageId ) {
  43                         $this->mId = $pageId; // page ID at time of deletion
  44                 } elseif ( $page->exists() ) {
  45                         $this->mId = $page->getId();
  46                 } else {
  47                         throw new InvalidArgumentException( "Page ID not known. Page doesn't exist?" );
  48                 }
  49
  50                 $this->timestamp = $timestamp ?: wfTimestampNow();
  51
  52                 $fakePO = new ParserOutput();
  53                 $fakePO->setCacheTime( $timestamp );
  54                 parent::__construct( $page->getTitle(), $fakePO, false );
  55         }
  56
  57         protected function doIncrementalUpdate() {
  58                 $services = MediaWikiServices::getInstance();
  59                 $config = $services->getMainConfig();
  60                 $lbFactory = $services->getDBLoadBalancerFactory();
  61                 $batchSize = $config->get( 'UpdateRowsPerQuery' );
  62
  63                 $id = $this->mId;
  64                 $title = $this->mTitle;
  65
  66                 $dbw = $this->getDB(); // convenience
  67
  68                 parent::doIncrementalUpdate();
  69
  70                 // Typically, a category is empty when deleted, so check that we don't leave
  71                 // spurious row in the category table.
  72                 if ( $title->getNamespace() === NS_CATEGORY ) {
  73                         // T166757: do the update after the main job DB commit
  74                         DeferredUpdates::addCallableUpdate( function () use ( $title ) {
  75                                 $cat = Category::newFromName( $title->getDBkey() );
  76                                 $cat->refreshCountsIfEmpty();
  77                         } );
  78                 }
  79
  80                 // Delete restrictions for the deleted page
  81                 $dbw->delete( 'page_restrictions', [ 'pr_page' => $id ], __METHOD__ );
  82
  83                 // Delete any redirect entry
  84                 $dbw->delete( 'redirect', [ 'rd_from' => $id ], __METHOD__ );
  85
  86                 // Find recentchanges entries to clean up...
  87                 $rcIdsForTitle = $dbw->selectFieldValues(
  88                         'recentchanges',
  89                         'rc_id',
  90                         [
  91                                 'rc_type != ' . RC_LOG,
  92                                 'rc_namespace' => $title->getNamespace(),
  93                                 'rc_title' => $title->getDBkey(),
  94                                 'rc_timestamp < ' .
  95                                         $dbw->addQuotes( $dbw->timestamp( $this->timestamp ) )
  96                         ],
  97                         __METHOD__
  98                 );
  99                 $rcIdsForPage = $dbw->selectFieldValues(
 100                         'recentchanges',
 101                         'rc_id',
 102                         [ 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ],
 103                         __METHOD__
 104                 );
 105
 106                 // T98706: delete by PK to avoid lock contention with RC delete log insertions
 107                 $rcIdBatches = array_chunk( array_merge( $rcIdsForTitle, $rcIdsForPage ), $batchSize );
 108                 foreach ( $rcIdBatches as $rcIdBatch ) {
 109                         $dbw->delete( 'recentchanges', [ 'rc_id' => $rcIdBatch ], __METHOD__ );
 110                         if ( count( $rcIdBatches ) > 1 ) {
 111                                 $lbFactory->commitAndWaitForReplication(
 112                                         __METHOD__, $this->ticket, [ 'domain' => $dbw->getDomainID() ]
 113                                 );
 114                         }
 115                 }
 116
 117                 // Commit and release the lock (if set)
 118                 ScopedCallback::consume( $scopedLock );
 119         }
 120
 121         public function getAsJobSpecification() {
 122                 return [
 123                         'domain' => $this->getDB()->getDomainID(),
 124                         'job' => new JobSpecification(
 125                                 'deleteLinks',
 126                                 [ 'pageId' => $this->mId, 'timestamp' => $this->timestamp ],
 127                                 [ 'removeDuplicates' => true ],
 128                                 $this->mTitle
 129                         )
 130                 ];
 131         }
 132 }