includes/jobqueue/jobs/HTMLCacheUpdateJob.php
<?php
/**
* 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\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Page\PageReference;
use MediaWiki\Title\Title;
/**
* Job to purge the HTML/file cache for all pages that link to or use another page or file
*
* This job comes in a few variants:
* - a) Recursive jobs to purge caches for backlink pages for a given title.
* These jobs have (recursive:true,table:<table>) set.
* - b) Jobs to purge caches for a set of titles (the job title is ignored).
* These jobs have (pages:(<page ID>:(<namespace>,<title>),...) set.
*
* @ingroup JobQueue
* @ingroup Cache
*/
class HTMLCacheUpdateJob extends Job {
/** @var int Lag safety margin when comparing root job time age to CDN max-age */
private const NORMAL_MAX_LAG = 10;
public function __construct( Title $title, array $params ) {
parent::__construct( 'htmlCacheUpdate', $title, $params );
// Avoid the overhead of de-duplication when it would be pointless.
// Note that these jobs always set page_touched to the current time,
// so letting the older existing job "win" is still correct.
$this->removeDuplicates = (
// Ranges rarely will line up
!isset( $params['range'] ) &&
// Multiple pages per job make matches unlikely
!( isset( $params['pages'] ) && count( $params['pages'] ) != 1 )
);
$this->params += [ 'causeAction' => 'HTMLCacheUpdateJob', 'causeAgent' => 'unknown' ];
}
/**
* @param PageReference $page Page to purge backlink pages from
* @param string $table Backlink table name
* @param array $params Additional job parameters
*
* @return HTMLCacheUpdateJob
*/
public static function newForBacklinks( PageReference $page, $table, $params = [] ) {
$title = Title::newFromPageReference( $page );
return new self(
$title,
[
'table' => $table,
'recursive' => true
] + Job::newRootJobParams( // "overall" refresh links job info
"htmlCacheUpdate:{$table}:{$title->getPrefixedText()}"
) + $params
);
}
public function run() {
$updateRowsPerJob = MediaWikiServices::getInstance()->getMainConfig()->get(
MainConfigNames::UpdateRowsPerJob );
$updateRowsPerQuery = MediaWikiServices::getInstance()->getMainConfig()->get(
MainConfigNames::UpdateRowsPerQuery );
if ( isset( $this->params['table'] ) && !isset( $this->params['pages'] ) ) {
$this->params['recursive'] = true; // b/c; base job
}
// Job to purge all (or a range of) backlink pages for a page
if ( !empty( $this->params['recursive'] ) ) {
// Carry over information for de-duplication
$extraParams = $this->getRootJobParams();
// Carry over cause information for logging
$extraParams['causeAction'] = $this->params['causeAction'];
$extraParams['causeAgent'] = $this->params['causeAgent'];
// Convert this into no more than $wgUpdateRowsPerJob HTMLCacheUpdateJob per-title
// jobs and possibly a recursive HTMLCacheUpdateJob job for the rest of the backlinks
$jobs = BacklinkJobUtils::partitionBacklinkJob(
$this,
$updateRowsPerJob,
$updateRowsPerQuery, // jobs-per-title
// Carry over information for de-duplication
[ 'params' => $extraParams ]
);
MediaWikiServices::getInstance()->getJobQueueGroup()->push( $jobs );
// Job to purge pages for a set of titles
} elseif ( isset( $this->params['pages'] ) ) {
$this->invalidateTitles( $this->params['pages'] );
// Job to update a single title
} else {
$t = $this->title;
$this->invalidateTitles( [
$t->getArticleID() => [ $t->getNamespace(), $t->getDBkey() ]
] );
}
return true;
}
/**
* @param array $pages Map of (page ID => (namespace, DB key)) entries
*/
protected function invalidateTitles( array $pages ) {
// Get all page IDs in this query into an array
$pageIds = array_keys( $pages );
if ( !$pageIds ) {
return;
}
$rootTsUnix = wfTimestampOrNull( TS_UNIX, $this->params['rootJobTimestamp'] ?? null );
// Bump page_touched to the current timestamp. This previously used the root job timestamp
// (e.g. template/file edit time), which is a bit more efficient when template edits are
// rare and don't effect the same pages much. However, this way better de-duplicates jobs,
// which is much more useful for wikis with high edit rates. Note that RefreshLinksJob,
// enqueued alongside HTMLCacheUpdateJob, saves the parser output since it has to parse
// anyway. We assume that vast majority of the cache jobs finish before the link jobs,
// so using the current timestamp instead of the root timestamp is not expected to
// invalidate these cache entries too often.
$newTouchedUnix = time();
// Timestamp used to bypass pages already invalided since the triggering event
$casTsUnix = $rootTsUnix ?? $newTouchedUnix;
$services = MediaWikiServices::getInstance();
$config = $services->getMainConfig();
$dbProvider = $services->getConnectionProvider();
$dbw = $dbProvider->getPrimaryDatabase();
$ticket = $dbProvider->getEmptyTransactionTicket( __METHOD__ );
// Update page_touched (skipping pages already touched since the root job).
// Check $wgUpdateRowsPerQuery; batch jobs are sized by that already.
$batches = array_chunk( $pageIds, $config->get( MainConfigNames::UpdateRowsPerQuery ) );
foreach ( $batches as $batch ) {
$dbw->newUpdateQueryBuilder()
->update( 'page' )
->set( [ 'page_touched' => $dbw->timestamp( $newTouchedUnix ) ] )
->where( [ 'page_id' => $batch ] )
->andWhere( $dbw->expr( 'page_touched', '<', $dbw->timestamp( $casTsUnix ) ) )
->caller( __METHOD__ )->execute();
if ( count( $batches ) > 1 ) {
$dbProvider->commitAndWaitForReplication( __METHOD__, $ticket );
}
}
// Get the list of affected pages (races only mean something else did the purge)
$queryBuilder = $dbw->newSelectQueryBuilder()
->select( [ 'page_namespace', 'page_title' ] )
->from( 'page' )
->where( [ 'page_id' => $pageIds, 'page_touched' => $dbw->timestamp( $newTouchedUnix ) ] );
if ( $config->get( MainConfigNames::PageLanguageUseDB ) ) {
$queryBuilder->field( 'page_lang' );
}
$titleArray = $services->getTitleFactory()->newTitleArrayFromResult(
$queryBuilder->caller( __METHOD__ )->fetchResultSet()
);
// Update CDN and file caches
$htmlCache = $services->getHtmlCacheUpdater();
$htmlCache->purgeTitleUrls(
$titleArray,
$htmlCache::PURGE_NAIVE | $htmlCache::PURGE_URLS_LINKSUPDATE_ONLY,
[ $htmlCache::UNLESS_CACHE_MTIME_AFTER => $casTsUnix + self::NORMAL_MAX_LAG ]
);
}
public function getDeduplicationInfo() {
$info = parent::getDeduplicationInfo();
if ( is_array( $info['params'] ) ) {
// 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['params']['pages'] ) ) {
unset( $info['namespace'] );
unset( $info['title'] );
}
}
return $info;
}
public function workItemCount() {
if ( !empty( $this->params['recursive'] ) ) {
return 0; // nothing actually purged
} elseif ( isset( $this->params['pages'] ) ) {
return count( $this->params['pages'] );
}
return 1; // one title
}
}