LinksDeletionUpdate.php

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<?php
namespace MediaWiki\Deferred\LinksUpdate;
 
use Category;
use DeferredUpdates;
use EnqueueableDataUpdate;
use InvalidArgumentException;
use JobSpecification;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MWException;
use ParserOutput;
use WikiPage;
 
class LinksDeletionUpdate extends LinksUpdate implements EnqueueableDataUpdate {
    protected $page;
    protected $timestamp;
 
    public function __construct( WikiPage $page, $pageId = null, $timestamp = null ) {
        $this->page = $page;
        if ( $pageId ) {
            $this->mId = $pageId; // page ID at time of deletion
        } elseif ( $page->exists() ) {
            $this->mId = $page->getId();
        } else {
            throw new InvalidArgumentException( "Page ID not known. Page doesn't exist?" );
        }
 
        $this->timestamp = $timestamp ?: wfTimestampNow();
 
        $fakePO = new ParserOutput();
        $fakePO->setCacheTime( $timestamp );
        // Use immutable page identity to keep reference to the page id at time of deletion - T299244
        $immutablePageIdentity = $page->getTitle()->toPageIdentity();
        parent::__construct( $immutablePageIdentity, $fakePO, false );
    }
 
    protected function doIncrementalUpdate() {
        $services = MediaWikiServices::getInstance();
        $config = $services->getMainConfig();
        $lbFactory = $services->getDBLoadBalancerFactory();
        $batchSize = $config->get( MainConfigNames::UpdateRowsPerQuery );
 
        $id = $this->mId;
        $title = $this->mTitle;
 
        $dbw = $this->getDB(); // convenience
 
        parent::doIncrementalUpdate();
 
        // Typically, a category is empty when deleted, so check that we don't leave
        // spurious row in the category table.
        if ( $title->getNamespace() === NS_CATEGORY ) {
            // T166757: do the update after the main job DB commit
            DeferredUpdates::addCallableUpdate( static function () use ( $title ) {
                $cat = Category::newFromName( $title->getDBkey() );
                $cat->refreshCountsIfSmall();
            } );
        }
 
        // Delete restrictions for the deleted page
        $dbw->delete( 'page_restrictions', [ 'pr_page' => $id ], __METHOD__ );
 
        // Delete any redirect entry
        $dbw->delete( 'redirect', [ 'rd_from' => $id ], __METHOD__ );
 
        // Find recentchanges entries to clean up...
        $rcIdsForTitle = $dbw->selectFieldValues(
            'recentchanges',
            'rc_id',
            [
                'rc_type != ' . RC_LOG,
                'rc_namespace' => $title->getNamespace(),
                'rc_title' => $title->getDBkey(),
                'rc_timestamp < ' .
                    $dbw->addQuotes( $dbw->timestamp( $this->timestamp ) )
            ],
            __METHOD__
        );
        $rcIdsForPage = $dbw->selectFieldValues(
            'recentchanges',
            'rc_id',
            [ 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ],
            __METHOD__
        );
 
        // T98706: delete by PK to avoid lock contention with RC delete log insertions
        $rcIdBatches = array_chunk( array_merge( $rcIdsForTitle, $rcIdsForPage ), $batchSize );
        foreach ( $rcIdBatches as $rcIdBatch ) {
            $dbw->delete( 'recentchanges', [ 'rc_id' => $rcIdBatch ], __METHOD__ );
            if ( count( $rcIdBatches ) > 1 ) {
                $lbFactory->commitAndWaitForReplication(
                    __METHOD__, $this->ticket, [ 'domain' => $dbw->getDomainID() ]
                );
            }
        }
    }
 
    public function getAsJobSpecification() {
        return [
            'domain' => $this->getDB()->getDomainID(),
            'job' => new JobSpecification(
                'deleteLinks',
                [ 'pageId' => $this->mId, 'timestamp' => $this->timestamp ],
                [ 'removeDuplicates' => true ],
                $this->mTitle
            )
        ];
    }
}
 
class_alias( LinksDeletionUpdate::class, 'LinksDeletionUpdate' );