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 /**
  23  * Update object handling the cleanup of links tables after a page was deleted.
  24  **/
  25 class LinksDeletionUpdate extends SqlDataUpdate implements EnqueueableDataUpdate {
  26         /** @var WikiPage */
  27         protected $page;
  28         /** @var integer */
  29         protected $pageId;
  30         /** @var string */
  31         protected $timestamp;
  32
  33         /**
  34          * @param WikiPage $page Page we are updating
  35          * @param integer|null $pageId ID of the page we are updating [optional]
  36          * @param string|null $timestamp TS_MW timestamp of deletion
  37          * @throws MWException
  38          */
  39         function __construct( WikiPage $page, $pageId = null, $timestamp = null ) {
  40                 parent::__construct( false ); // no implicit transaction
  41
  42                 $this->page = $page;
  43                 if ( $pageId ) {
  44                         $this->pageId = $pageId; // page ID at time of deletion
  45                 } elseif ( $page->exists() ) {
  46                         $this->pageId = $page->getId();
  47                 } else {
  48                         throw new InvalidArgumentException( "Page ID not known. Page doesn't exist?" );
  49                 }
  50
  51                 $this->timestamp = $timestamp ?: wfTimestampNow();
  52         }
  53
  54         public function doUpdate() {
  55                 $config = RequestContext::getMain()->getConfig();
  56                 $batchSize = $config->get( 'UpdateRowsPerQuery' );
  57
  58                 // Page may already be deleted, so don't just getId()
  59                 $id = $this->pageId;
  60                 // Make sure all links update threads see the changes of each other.
  61                 // This handles the case when updates have to batched into several COMMITs.
  62                 $scopedLock = LinksUpdate::acquirePageLock( $this->mDb, $id );
  63
  64                 $title = $this->page->getTitle();
  65
  66                 // Delete restrictions for it
  67                 $this->mDb->delete( 'page_restrictions', [ 'pr_page' => $id ], __METHOD__ );
  68
  69                 // Fix category table counts
  70                 $cats = $this->mDb->selectFieldValues(
  71                         'categorylinks',
  72                         'cl_to',
  73                         [ 'cl_from' => $id ],
  74                         __METHOD__
  75                 );
  76                 $catBatches = array_chunk( $cats, $batchSize );
  77                 foreach ( $catBatches as $catBatch ) {
  78                         $this->page->updateCategoryCounts( [], $catBatch, $id );
  79                         if ( count( $catBatches ) > 1 ) {
  80                                 $this->mDb->commit( __METHOD__, 'flush' );
  81                                 wfGetLBFactory()->waitForReplication( [ 'wiki' => $this->mDb->getWikiID() ] );
  82                         }
  83                 }
  84
  85                 // Refresh the category table entry if it seems to have no pages. Check
  86                 // master for the most up-to-date cat_pages count.
  87                 if ( $title->getNamespace() === NS_CATEGORY ) {
  88                         $row = $this->mDb->selectRow(
  89                                 'category',
  90                                 [ 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ],
  91                                 [ 'cat_title' => $title->getDBkey(), 'cat_pages <= 0' ],
  92                                 __METHOD__
  93                         );
  94                         if ( $row ) {
  95                                 $cat = Category::newFromRow( $row, $title )->refreshCounts();
  96                         }
  97                 }
  98
  99                 // If using cascading deletes, we can skip some explicit deletes
 100                 if ( !$this->mDb->cascadingDeletes() ) {
 101                         // Delete outgoing links
 102                         $this->batchDeleteByPK(
 103                                 'pagelinks',
 104                                 [ 'pl_from' => $id ],
 105                                 [ 'pl_from', 'pl_namespace', 'pl_title' ],
 106                                 $batchSize
 107                         );
 108                         $this->batchDeleteByPK(
 109                                 'imagelinks',
 110                                 [ 'il_from' => $id ],
 111                                 [ 'il_from', 'il_to' ],
 112                                 $batchSize
 113                         );
 114                         $this->batchDeleteByPK(
 115                                 'categorylinks',
 116                                 [ 'cl_from' => $id ],
 117                                 [ 'cl_from', 'cl_to' ],
 118                                 $batchSize
 119                         );
 120                         $this->batchDeleteByPK(
 121                                 'templatelinks',
 122                                 [ 'tl_from' => $id ],
 123                                 [ 'tl_from', 'tl_namespace', 'tl_title' ],
 124                                 $batchSize
 125                         );
 126                         $this->batchDeleteByPK(
 127                                 'externallinks',
 128                                 [ 'el_from' => $id ],
 129                                 [ 'el_id' ],
 130                                 $batchSize
 131                         );
 132                         $this->batchDeleteByPK(
 133                                 'langlinks',
 134                                 [ 'll_from' => $id ],
 135                                 [ 'll_from', 'll_lang' ],
 136                                 $batchSize
 137                         );
 138                         $this->batchDeleteByPK(
 139                                 'iwlinks',
 140                                 [ 'iwl_from' => $id ],
 141                                 [ 'iwl_from', 'iwl_prefix', 'iwl_title' ],
 142                                 $batchSize
 143                         );
 144                         // Delete any redirect entry or page props entries
 145                         $this->mDb->delete( 'redirect', [ 'rd_from' => $id ], __METHOD__ );
 146                         $this->mDb->delete( 'page_props', [ 'pp_page' => $id ], __METHOD__ );
 147                 }
 148
 149                 // If using cleanup triggers, we can skip some manual deletes
 150                 if ( !$this->mDb->cleanupTriggers() ) {
 151                         // Find recentchanges entries to clean up...
 152                         $rcIdsForTitle = $this->mDb->selectFieldValues(
 153                                 'recentchanges',
 154                                 'rc_id',
 155                                 [
 156                                         'rc_type != ' . RC_LOG,
 157                                         'rc_namespace' => $title->getNamespace(),
 158                                         'rc_title' => $title->getDBkey(),
 159                                         'rc_timestamp < ' .
 160                                                 $this->mDb->addQuotes( $this->mDb->timestamp( $this->timestamp ) )
 161                                 ],
 162                                 __METHOD__
 163                         );
 164                         $rcIdsForPage = $this->mDb->selectFieldValues(
 165                                 'recentchanges',
 166                                 'rc_id',
 167                                 [ 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ],
 168                                 __METHOD__
 169                         );
 170
 171                         // T98706: delete by PK to avoid lock contention with RC delete log insertions
 172                         $rcIdBatches = array_chunk( array_merge( $rcIdsForTitle, $rcIdsForPage ), $batchSize );
 173                         foreach ( $rcIdBatches as $rcIdBatch ) {
 174                                 $this->mDb->delete( 'recentchanges', [ 'rc_id' => $rcIdBatch ], __METHOD__ );
 175                                 if ( count( $rcIdBatches ) > 1 ) {
 176                                         $this->mDb->commit( __METHOD__, 'flush' );
 177                                         wfGetLBFactory()->waitForReplication( [ 'wiki' => $this->mDb->getWikiID() ] );
 178                                 }
 179                         }
 180                 }
 181
 182                 // Commit and release the lock
 183                 ScopedCallback::consume( $scopedLock );
 184         }
 185
 186         private function batchDeleteByPK( $table, array $conds, array $pk, $bSize ) {
 187                 $dbw = $this->mDb; // convenience
 188                 $res = $dbw->select( $table, $pk, $conds, __METHOD__ );
 189
 190                 $pkDeleteConds = [];
 191                 foreach ( $res as $row ) {
 192                         $pkDeleteConds[] = $this->mDb->makeList( (array)$row, LIST_AND );
 193                         if ( count( $pkDeleteConds ) >= $bSize ) {
 194                                 $dbw->delete( $table, $dbw->makeList( $pkDeleteConds, LIST_OR ), __METHOD__ );
 195                                 $dbw->commit( __METHOD__, 'flush' );
 196                                 wfGetLBFactory()->waitForReplication( [ 'wiki' => $dbw->getWikiID() ] );
 197                                 $pkDeleteConds = [];
 198                         }
 199                 }
 200
 201                 if ( $pkDeleteConds ) {
 202                         $dbw->delete( $table, $dbw->makeList( $pkDeleteConds, LIST_OR ), __METHOD__ );
 203                 }
 204         }
 205
 206         public function getAsJobSpecification() {
 207                 return [
 208                         'wiki' => $this->mDb->getWikiID(),
 209                         'job'  => new JobSpecification(
 210                                 'deleteLinks',
 211                                 [ 'pageId' => $this->pageId, 'timestamp' => $this->timestamp ],
 212                                 [ 'removeDuplicates' => true ],
 213                                 $this->page->getTitle()
 214                         )
 215                 ];
 216         }
 217 }