--- /dev/null
+<?php
+/**
+ * Updater for link tracking tables after a page edit.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+use MediaWiki\MediaWikiServices;
+use Wikimedia\Rdbms\LBFactory;
+
+/**
+ * Job to add recent change entries mentioning category membership changes
+ *
+ * Parameters include:
+ * - pageId : page ID
+ * - revTimestamp : timestamp of the triggering revision
+ *
+ * Category changes will be mentioned for revisions at/after the timestamp for this page
+ *
+ * @since 1.27
+ */
+class CategoryMembershipChangeJob extends Job {
+ /** @var int|null */
+ private $ticket;
+
+ const ENQUEUE_FUDGE_SEC = 60;
+
+ public function __construct( Title $title, array $params ) {
+ parent::__construct( 'categoryMembershipChange', $title, $params );
+ // Only need one job per page. Note that ENQUEUE_FUDGE_SEC handles races where an
+ // older revision job gets inserted while the newer revision job is de-duplicated.
+ $this->removeDuplicates = true;
+ }
+
+ public function run() {
+ $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+ $lb = $lbFactory->getMainLB();
+ $dbw = $lb->getConnection( DB_MASTER );
+
+ $this->ticket = $lbFactory->getEmptyTransactionTicket( __METHOD__ );
+
+ $page = WikiPage::newFromID( $this->params['pageId'], WikiPage::READ_LATEST );
+ if ( !$page ) {
+ $this->setLastError( "Could not find page #{$this->params['pageId']}" );
+ return false; // deleted?
+ }
+
+ // Use a named lock so that jobs for this page see each others' changes
+ $lockKey = "CategoryMembershipUpdates:{$page->getId()}";
+ $scopedLock = $dbw->getScopedLockAndFlush( $lockKey, __METHOD__, 3 );
+ if ( !$scopedLock ) {
+ $this->setLastError( "Could not acquire lock '$lockKey'" );
+ return false;
+ }
+
+ $dbr = $lb->getConnection( DB_REPLICA, [ 'recentchanges' ] );
+ // Wait till the replica DB is caught up so that jobs for this page see each others' changes
+ if ( !$lb->safeWaitForMasterPos( $dbr ) ) {
+ $this->setLastError( "Timed out while waiting for replica DB to catch up" );
+ return false;
+ }
+ // Clear any stale REPEATABLE-READ snapshot
+ $dbr->flushSnapshot( __METHOD__ );
+
+ $cutoffUnix = wfTimestamp( TS_UNIX, $this->params['revTimestamp'] );
+ // Using ENQUEUE_FUDGE_SEC handles jobs inserted out of revision order due to the delay
+ // between COMMIT and actual enqueueing of the CategoryMembershipChangeJob job.
+ $cutoffUnix -= self::ENQUEUE_FUDGE_SEC;
+
+ // Get the newest revision that has a SRC_CATEGORIZE row...
+ $row = $dbr->selectRow(
+ [ 'revision', 'recentchanges' ],
+ [ 'rev_timestamp', 'rev_id' ],
+ [
+ 'rev_page' => $page->getId(),
+ 'rev_timestamp >= ' . $dbr->addQuotes( $dbr->timestamp( $cutoffUnix ) )
+ ],
+ __METHOD__,
+ [ 'ORDER BY' => 'rev_timestamp DESC, rev_id DESC' ],
+ [
+ 'recentchanges' => [
+ 'INNER JOIN',
+ [
+ 'rc_this_oldid = rev_id',
+ 'rc_source' => RecentChange::SRC_CATEGORIZE,
+ // Allow rc_cur_id or rc_timestamp index usage
+ 'rc_cur_id = rev_page',
+ 'rc_timestamp >= rev_timestamp'
+ ]
+ ]
+ ]
+ );
+ // Only consider revisions newer than any such revision
+ if ( $row ) {
+ $cutoffUnix = wfTimestamp( TS_UNIX, $row->rev_timestamp );
+ $lastRevId = (int)$row->rev_id;
+ } else {
+ $lastRevId = 0;
+ }
+
+ // Find revisions to this page made around and after this revision which lack category
+ // notifications in recent changes. This lets jobs pick up were the last one left off.
+ $encCutoff = $dbr->addQuotes( $dbr->timestamp( $cutoffUnix ) );
+ $res = $dbr->select(
+ 'revision',
+ Revision::selectFields(),
+ [
+ 'rev_page' => $page->getId(),
+ "rev_timestamp > $encCutoff" .
+ " OR (rev_timestamp = $encCutoff AND rev_id > $lastRevId)"
+ ],
+ __METHOD__,
+ [ 'ORDER BY' => 'rev_timestamp ASC, rev_id ASC' ]
+ );
+
+ // Apply all category updates in revision timestamp order
+ foreach ( $res as $row ) {
+ $this->notifyUpdatesForRevision( $lbFactory, $page, Revision::newFromRow( $row ) );
+ }
+
+ return true;
+ }
+
+ /**
+ * @param LBFactory $lbFactory
+ * @param WikiPage $page
+ * @param Revision $newRev
+ * @throws MWException
+ */
+ protected function notifyUpdatesForRevision(
+ LBFactory $lbFactory, WikiPage $page, Revision $newRev
+ ) {
+ $config = RequestContext::getMain()->getConfig();
+ $title = $page->getTitle();
+
+ // Get the new revision
+ if ( !$newRev->getContent() ) {
+ return; // deleted?
+ }
+
+ // Get the prior revision (the same for null edits)
+ if ( $newRev->getParentId() ) {
+ $oldRev = Revision::newFromId( $newRev->getParentId(), Revision::READ_LATEST );
+ if ( !$oldRev->getContent() ) {
+ return; // deleted?
+ }
+ } else {
+ $oldRev = null;
+ }
+
+ // Parse the new revision and get the categories
+ $categoryChanges = $this->getExplicitCategoriesChanges( $title, $newRev, $oldRev );
+ list( $categoryInserts, $categoryDeletes ) = $categoryChanges;
+ if ( !$categoryInserts && !$categoryDeletes ) {
+ return; // nothing to do
+ }
+
+ $catMembChange = new CategoryMembershipChange( $title, $newRev );
+ $catMembChange->checkTemplateLinks();
+
+ $batchSize = $config->get( 'UpdateRowsPerQuery' );
+ $insertCount = 0;
+
+ foreach ( $categoryInserts as $categoryName ) {
+ $categoryTitle = Title::makeTitle( NS_CATEGORY, $categoryName );
+ $catMembChange->triggerCategoryAddedNotification( $categoryTitle );
+ if ( $insertCount++ && ( $insertCount % $batchSize ) == 0 ) {
+ $lbFactory->commitAndWaitForReplication( __METHOD__, $this->ticket );
+ }
+ }
+
+ foreach ( $categoryDeletes as $categoryName ) {
+ $categoryTitle = Title::makeTitle( NS_CATEGORY, $categoryName );
+ $catMembChange->triggerCategoryRemovedNotification( $categoryTitle );
+ if ( $insertCount++ && ( $insertCount++ % $batchSize ) == 0 ) {
+ $lbFactory->commitAndWaitForReplication( __METHOD__, $this->ticket );
+ }
+ }
+ }
+
+ private function getExplicitCategoriesChanges(
+ Title $title, Revision $newRev, Revision $oldRev = null
+ ) {
+ // Inject the same timestamp for both revision parses to avoid seeing category changes
+ // due to time-based parser functions. Inject the same page title for the parses too.
+ // Note that REPEATABLE-READ makes template/file pages appear unchanged between parses.
+ $parseTimestamp = $newRev->getTimestamp();
+ // Parse the old rev and get the categories. Do not use link tables as that
+ // assumes these updates are perfectly FIFO and that link tables are always
+ // up to date, neither of which are true.
+ $oldCategories = $oldRev
+ ? $this->getCategoriesAtRev( $title, $oldRev, $parseTimestamp )
+ : [];
+ // Parse the new revision and get the categories
+ $newCategories = $this->getCategoriesAtRev( $title, $newRev, $parseTimestamp );
+
+ $categoryInserts = array_values( array_diff( $newCategories, $oldCategories ) );
+ $categoryDeletes = array_values( array_diff( $oldCategories, $newCategories ) );
+
+ return [ $categoryInserts, $categoryDeletes ];
+ }
+
+ /**
+ * @param Title $title
+ * @param Revision $rev
+ * @param string $parseTimestamp TS_MW
+ *
+ * @return string[] category names
+ */
+ private function getCategoriesAtRev( Title $title, Revision $rev, $parseTimestamp ) {
+ $content = $rev->getContent();
+ $options = $content->getContentHandler()->makeParserOptions( 'canonical' );
+ $options->setTimestamp( $parseTimestamp );
+ // This could possibly use the parser cache if it checked the revision ID,
+ // but that's more complicated than it's worth.
+ $output = $content->getParserOutput( $title, $rev->getId(), $options );
+
+ // array keys will cast numeric category names to ints
+ // so we need to cast them back to strings to avoid breaking things!
+ return array_map( 'strval', array_keys( $output->getCategories() ) );
+ }
+
+ public function getDeduplicationInfo() {
+ $info = parent::getDeduplicationInfo();
+ unset( $info['params']['revTimestamp'] ); // first job wins
+
+ return $info;
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff