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Diffstat (limited to 'includes/jobqueue/jobs/RefreshLinksJob.php')
| -rw-r--r-- | includes/jobqueue/jobs/RefreshLinksJob.php | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/includes/jobqueue/jobs/RefreshLinksJob.php b/includes/jobqueue/jobs/RefreshLinksJob.php new file mode 100644 index 00000000..f82af273 --- /dev/null +++ b/includes/jobqueue/jobs/RefreshLinksJob.php @@ -0,0 +1,199 @@ +<?php +/** + * Job to update link tables for pages + * + * 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 + * @ingroup JobQueue + */ + +/** + * Job to update link tables for pages + * + * This job comes in a few variants: + * - a) Recursive jobs to update links for backlink pages for a given title. + * These jobs have have (recursive:true,table:<table>) set. + * - b) Jobs to update links for a set of pages (the job title is ignored). + * These jobs have have (pages:(<page ID>:(<namespace>,<title>),...) set. + * - c) Jobs to update links for a single page (the job title) + * These jobs need no extra fields set. + * + * @ingroup JobQueue + */ +class RefreshLinksJob extends Job { + const PARSE_THRESHOLD_SEC = 1.0; + + function __construct( $title, $params = '' ) { + parent::__construct( 'refreshLinks', $title, $params ); + // Base backlink update jobs and per-title update jobs can be de-duplicated. + // If template A changes twice before any jobs run, a clean queue will have: + // (A base, A base) + // The second job is ignored by the queue on insertion. + // Suppose, many pages use template A, and that template itself uses template B. + // An edit to both will first create two base jobs. A clean FIFO queue will have: + // (A base, B base) + // When these jobs run, the queue will have per-title and remnant partition jobs: + // (titleX,titleY,titleZ,...,A remnant,titleM,titleN,titleO,...,B remnant) + // Some these jobs will be the same, and will automatically be ignored by + // the queue upon insertion. Some title jobs will run before the duplicate is + // inserted, so the work will still be done twice in those cases. More titles + // can be de-duplicated as the remnant jobs continue to be broken down. This + // works best when $wgUpdateRowsPerJob, and either the pages have few backlinks + // and/or the backlink sets for pages A and B are almost identical. + $this->removeDuplicates = !isset( $params['range'] ) + && ( !isset( $params['pages'] ) || count( $params['pages'] ) == 1 ); + } + + function run() { + global $wgUpdateRowsPerJob; + + // Job to update all (or a range of) backlink pages for a page + if ( !empty( $this->params['recursive'] ) ) { + // Carry over information for de-duplication + $extraParams = $this->getRootJobParams(); + // Avoid slave lag when fetching templates. + // When the outermost job is run, we know that the caller that enqueued it must have + // committed the relevant changes to the DB by now. At that point, record the master + // position and pass it along as the job recursively breaks into smaller range jobs. + // Hopefully, when leaf jobs are popped, the slaves will have reached that position. + if ( isset( $this->params['masterPos'] ) ) { + $extraParams['masterPos'] = $this->params['masterPos']; + } elseif ( wfGetLB()->getServerCount() > 1 ) { + $extraParams['masterPos'] = wfGetLB()->getMasterPos(); + } else { + $extraParams['masterPos'] = false; + } + // Convert this into no more than $wgUpdateRowsPerJob RefreshLinks per-title + // jobs and possibly a recursive RefreshLinks job for the rest of the backlinks + $jobs = BacklinkJobUtils::partitionBacklinkJob( + $this, + $wgUpdateRowsPerJob, + 1, // job-per-title + array( 'params' => $extraParams ) + ); + JobQueueGroup::singleton()->push( $jobs ); + // Job to update link tables for for a set of titles + } elseif ( isset( $this->params['pages'] ) ) { + foreach ( $this->params['pages'] as $pageId => $nsAndKey ) { + list( $ns, $dbKey ) = $nsAndKey; + $this->runForTitle( Title::makeTitleSafe( $ns, $dbKey ) ); + } + // Job to update link tables for a given title + } else { + $this->runForTitle( $this->title ); + } + + return true; + } + + protected function runForTitle( Title $title = null ) { + $linkCache = LinkCache::singleton(); + $linkCache->clear(); + + if ( is_null( $title ) ) { + $this->setLastError( "refreshLinks: Invalid title" ); + return false; + } + + // Wait for the DB of the current/next slave DB handle to catch up to the master. + // This way, we get the correct page_latest for templates or files that just changed + // milliseconds ago, having triggered this job to begin with. + if ( isset( $this->params['masterPos'] ) && $this->params['masterPos'] !== false ) { + wfGetLB()->waitFor( $this->params['masterPos'] ); + } + + $page = WikiPage::factory( $title ); + + // Fetch the current revision... + $revision = Revision::newFromTitle( $title, false, Revision::READ_NORMAL ); + if ( !$revision ) { + $this->setLastError( "refreshLinks: Article not found {$title->getPrefixedDBkey()}" ); + return false; // XXX: what if it was just deleted? + } + $content = $revision->getContent( Revision::RAW ); + if ( !$content ) { + // If there is no content, pretend the content is empty + $content = $revision->getContentHandler()->makeEmptyContent(); + } + + $parserOutput = false; + $parserOptions = $page->makeParserOptions( 'canonical' ); + // If page_touched changed after this root job (with a good slave lag skew factor), + // then it is likely that any views of the pages already resulted in re-parses which + // are now in cache. This can be reused to avoid expensive parsing in some cases. + if ( isset( $this->params['rootJobTimestamp'] ) ) { + $skewedTimestamp = wfTimestamp( TS_UNIX, $this->params['rootJobTimestamp'] ) + 5; + if ( $page->getLinksTimestamp() > wfTimestamp( TS_MW, $skewedTimestamp ) ) { + // Something already updated the backlinks since this job was made + return true; + } + if ( $page->getTouched() > wfTimestamp( TS_MW, $skewedTimestamp ) ) { + $parserOutput = ParserCache::singleton()->getDirty( $page, $parserOptions ); + if ( $parserOutput && $parserOutput->getCacheTime() <= $skewedTimestamp ) { + $parserOutput = false; // too stale + } + } + } + // Fetch the current revision and parse it if necessary... + if ( $parserOutput == false ) { + $start = microtime( true ); + // Revision ID must be passed to the parser output to get revision variables correct + $parserOutput = $content->getParserOutput( + $title, $revision->getId(), $parserOptions, false ); + $ellapsed = microtime( true ) - $start; + // If it took a long time to render, then save this back to the cache to avoid + // wasted CPU by other apaches or job runners. We don't want to always save to + // cache as this cause cause high cache I/O and LRU churn when a template changes. + if ( $ellapsed >= self::PARSE_THRESHOLD_SEC + && $page->isParserCacheUsed( $parserOptions, $revision->getId() ) + && $parserOutput->isCacheable() + ) { + $ctime = wfTimestamp( TS_MW, (int)$start ); // cache time + ParserCache::singleton()->save( + $parserOutput, $page, $parserOptions, $ctime, $revision->getId() + ); + } + } + + $updates = $content->getSecondaryDataUpdates( $title, null, false, $parserOutput ); + DataUpdate::runUpdates( $updates ); + + InfoAction::invalidateCache( $title ); + + return true; + } + + public function getDeduplicationInfo() { + $info = parent::getDeduplicationInfo(); + if ( is_array( $info['params'] ) ) { + // Don't let highly unique "masterPos" values ruin duplicate detection + unset( $info['params']['masterPos'] ); + // For per-pages jobs, the job title is that of the template that changed + // (or similar), so remove that since it ruins duplicate detection + if ( isset( $info['pages'] ) ) { + unset( $info['namespace'] ); + unset( $info['title'] ); + } + } + + return $info; + } + + public function workItemCount() { + return isset( $this->params['pages'] ) ? count( $this->params['pages'] ) : 1; + } +} |