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