<?php
+/**
+ * Cache for outputs of the PHP parser
+ *
+ * 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 Cache Parser
+ */
+
+use MediaWiki\MediaWikiServices;
+
/**
* @ingroup Cache Parser
* @todo document
*/
class ParserCache {
+ /**
+ * Constants for self::getKey()
+ * @since 1.30
+ */
+
+ /** Use only current data */
+ const USE_CURRENT_ONLY = 0;
+
+ /** Use expired data if current data is unavailable */
+ const USE_EXPIRED = 1;
+
+ /** Use expired data or data from different revisions if current data is unavailable */
+ const USE_OUTDATED = 2;
+
+ /**
+ * Use expired data and data from different revisions, and if all else
+ * fails vary on all variable options
+ */
+ const USE_ANYTHING = 3;
+
+ /** @var BagOStuff */
+ private $mMemc;
+
+ /**
+ * Anything cached prior to this is invalidated
+ *
+ * @var string
+ */
+ private $cacheEpoch;
/**
* Get an instance of this object
+ *
+ * @deprecated since 1.30, use MediaWikiServices instead
+ * @return ParserCache
*/
- public static function &singleton() {
- static $instance;
- if ( !isset( $instance ) ) {
- global $parserMemc;
- $instance = new ParserCache( $parserMemc );
- }
- return $instance;
+ public static function singleton() {
+ return MediaWikiServices::getInstance()->getParserCache();
}
/**
* Setup a cache pathway with a given back-end storage mechanism.
- * May be a memcached client or a BagOStuff derivative.
*
- * @param object $memCached
+ * This class use an invalidation strategy that is compatible with
+ * MultiWriteBagOStuff in async replication mode.
+ *
+ * @param BagOStuff $cache
+ * @param string $cacheEpoch Anything before this timestamp is invalidated
+ * @throws MWException
*/
- function __construct( &$memCached ) {
- $this->mMemc =& $memCached;
+ public function __construct( BagOStuff $cache, $cacheEpoch = '20030516000000' ) {
+ $this->mMemc = $cache;
+ $this->cacheEpoch = $cacheEpoch;
}
- function getKey( &$article, $popts ) {
+ /**
+ * @param WikiPage $article
+ * @param string $hash
+ * @return mixed|string
+ */
+ protected function getParserOutputKey( $article, $hash ) {
global $wgRequest;
- if( $popts instanceof User ) // It used to be getKey( &$article, &$user )
- $popts = ParserOptions::newFromUser( $popts );
+ // idhash seem to mean 'page id' + 'rendering hash' (r3710)
+ $pageid = $article->getId();
+ $renderkey = (int)( $wgRequest->getVal( 'action' ) == 'render' );
- $user = $popts->mUser;
- $printable = ( $popts->getIsPrintable() ) ? '!printable=1' : '';
- $hash = $user->getPageRenderingHash();
- if( !$article->mTitle->quickUserCan( 'edit' ) ) {
- // section edit links are suppressed even if the user has them on
- $edit = '!edit=0';
- } else {
- $edit = '';
- }
- $pageid = $article->getID();
- $renderkey = (int)($wgRequest->getVal('action') == 'render');
- $key = wfMemcKey( 'pcache', 'idhash', "{$pageid}-{$renderkey}!{$hash}{$edit}{$printable}" );
+ $key = $this->mMemc->makeKey( 'pcache', 'idhash', "{$pageid}-{$renderkey}!{$hash}" );
return $key;
}
- function getETag( &$article, $popts ) {
- return 'W/"' . $this->getKey($article, $popts) . "--" . $article->mTouched. '"';
+ /**
+ * @param WikiPage $page
+ * @return mixed|string
+ */
+ protected function getOptionsKey( $page ) {
+ return $this->mMemc->makeKey( 'pcache', 'idoptions', $page->getId() );
}
- function get( &$article, $popts ) {
- global $wgCacheEpoch;
- $fname = 'ParserCache::get';
- wfProfileIn( $fname );
+ /**
+ * @param WikiPage $page
+ * @since 1.28
+ */
+ public function deleteOptionsKey( $page ) {
+ $this->mMemc->delete( $this->getOptionsKey( $page ) );
+ }
- $key = $this->getKey( $article, $popts );
+ /**
+ * Provides an E-Tag suitable for the whole page. Note that $article
+ * is just the main wikitext. The E-Tag has to be unique to the whole
+ * page, even if the article itself is the same, so it uses the
+ * complete set of user options. We don't want to use the preference
+ * of a different user on a message just because it wasn't used in
+ * $article. For example give a Chinese interface to a user with
+ * English preferences. That's why we take into account *all* user
+ * options. (r70809 CR)
+ *
+ * @param WikiPage $article
+ * @param ParserOptions $popts
+ * @return string
+ */
+ public function getETag( $article, $popts ) {
+ return 'W/"' . $this->getParserOutputKey( $article,
+ $popts->optionsHash( ParserOptions::allCacheVaryingOptions(), $article->getTitle() ) ) .
+ "--" . $article->getTouched() . '"';
+ }
- wfDebug( "Trying parser cache $key\n" );
- $value = $this->mMemc->get( $key );
- if ( is_object( $value ) ) {
- wfDebug( "Found.\n" );
- # Delete if article has changed since the cache was made
- $canCache = $article->checkTouched();
- $cacheTime = $value->getCacheTime();
- $touched = $article->mTouched;
- if ( !$canCache || $value->expired( $touched ) ) {
- if ( !$canCache ) {
- wfIncrStats( "pcache_miss_invalid" );
- wfDebug( "Invalid cached redirect, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
- } else {
- wfIncrStats( "pcache_miss_expired" );
- wfDebug( "Key expired, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
- }
- $this->mMemc->delete( $key );
- $value = false;
- } else {
- if ( isset( $value->mTimestamp ) ) {
- $article->mTimestamp = $value->mTimestamp;
- }
- wfIncrStats( "pcache_hit" );
+ /**
+ * Retrieve the ParserOutput from ParserCache, even if it's outdated.
+ * @param WikiPage $article
+ * @param ParserOptions $popts
+ * @return ParserOutput|bool False on failure
+ */
+ public function getDirty( $article, $popts ) {
+ $value = $this->get( $article, $popts, true );
+ return is_object( $value ) ? $value : false;
+ }
+
+ /**
+ * Generates a key for caching the given article considering
+ * the given parser options.
+ *
+ * @note Which parser options influence the cache key
+ * is controlled via ParserOutput::recordOption() or
+ * ParserOptions::addExtraKey().
+ *
+ * @note Used by Article to provide a unique id for the PoolCounter.
+ * It would be preferable to have this code in get()
+ * instead of having Article looking in our internals.
+ *
+ * @param WikiPage $article
+ * @param ParserOptions $popts
+ * @param int|bool $useOutdated One of the USE constants. For backwards
+ * compatibility, boolean false is treated as USE_CURRENT_ONLY and
+ * boolean true is treated as USE_ANYTHING.
+ * @return bool|mixed|string
+ * @since 1.30 Changed $useOutdated to an int and added the non-boolean values
+ */
+ public function getKey( $article, $popts, $useOutdated = self::USE_ANYTHING ) {
+ if ( is_bool( $useOutdated ) ) {
+ $useOutdated = $useOutdated ? self::USE_ANYTHING : self::USE_CURRENT_ONLY;
+ }
+
+ if ( $popts instanceof User ) {
+ wfWarn( "Use of outdated prototype ParserCache::getKey( &\$article, &\$user )\n" );
+ $popts = ParserOptions::newFromUser( $popts );
+ }
+
+ // Determine the options which affect this article
+ $casToken = null;
+ $optionsKey = $this->mMemc->get(
+ $this->getOptionsKey( $article ), $casToken, BagOStuff::READ_VERIFIED );
+ if ( $optionsKey instanceof CacheTime ) {
+ if ( $useOutdated < self::USE_EXPIRED && $optionsKey->expired( $article->getTouched() ) ) {
+ wfIncrStats( "pcache.miss.expired" );
+ $cacheTime = $optionsKey->getCacheTime();
+ wfDebugLog( "ParserCache",
+ "Parser options key expired, touched " . $article->getTouched()
+ . ", epoch {$this->cacheEpoch}, cached $cacheTime\n" );
+ return false;
+ } elseif ( $useOutdated < self::USE_OUTDATED &&
+ $optionsKey->isDifferentRevision( $article->getLatest() )
+ ) {
+ wfIncrStats( "pcache.miss.revid" );
+ $revId = $article->getLatest();
+ $cachedRevId = $optionsKey->getCacheRevisionId();
+ wfDebugLog( "ParserCache",
+ "ParserOutput key is for an old revision, latest $revId, cached $cachedRevId\n"
+ );
+ return false;
}
+
+ // $optionsKey->mUsedOptions is set by save() by calling ParserOutput::getUsedOptions()
+ $usedOptions = $optionsKey->mUsedOptions;
+ wfDebug( "Parser cache options found.\n" );
} else {
- wfDebug( "Parser cache miss.\n" );
- wfIncrStats( "pcache_miss_absent" );
+ if ( $useOutdated < self::USE_ANYTHING ) {
+ return false;
+ }
+ $usedOptions = ParserOptions::allCacheVaryingOptions();
+ }
+
+ return $this->getParserOutputKey(
+ $article,
+ $popts->optionsHash( $usedOptions, $article->getTitle() )
+ );
+ }
+
+ /**
+ * Retrieve the ParserOutput from ParserCache.
+ * false if not found or outdated.
+ *
+ * @param WikiPage|Article $article
+ * @param ParserOptions $popts
+ * @param bool $useOutdated (default false)
+ *
+ * @return ParserOutput|bool False on failure
+ */
+ public function get( $article, $popts, $useOutdated = false ) {
+ $canCache = $article->checkTouched();
+ if ( !$canCache ) {
+ // It's a redirect now
+ return false;
+ }
+
+ $touched = $article->getTouched();
+
+ $parserOutputKey = $this->getKey( $article, $popts,
+ $useOutdated ? self::USE_OUTDATED : self::USE_CURRENT_ONLY
+ );
+ if ( $parserOutputKey === false ) {
+ wfIncrStats( 'pcache.miss.absent' );
+ return false;
+ }
+
+ $casToken = null;
+ /** @var ParserOutput $value */
+ $value = $this->mMemc->get( $parserOutputKey, $casToken, BagOStuff::READ_VERIFIED );
+ if ( !$value ) {
+ wfDebug( "ParserOutput cache miss.\n" );
+ wfIncrStats( "pcache.miss.absent" );
+ return false;
+ }
+
+ wfDebug( "ParserOutput cache found.\n" );
+
+ // The edit section preference may not be the appropiate one in
+ // the ParserOutput, as we are not storing it in the parsercache
+ // key. Force it here. See T33445.
+ $value->setEditSectionTokens( $popts->getEditSection() );
+
+ $wikiPage = method_exists( $article, 'getPage' )
+ ? $article->getPage()
+ : $article;
+
+ if ( !$useOutdated && $value->expired( $touched ) ) {
+ wfIncrStats( "pcache.miss.expired" );
+ $cacheTime = $value->getCacheTime();
+ wfDebugLog( "ParserCache",
+ "ParserOutput key expired, touched $touched, "
+ . "epoch {$this->cacheEpoch}, cached $cacheTime\n" );
$value = false;
+ } elseif ( !$useOutdated && $value->isDifferentRevision( $article->getLatest() ) ) {
+ wfIncrStats( "pcache.miss.revid" );
+ $revId = $article->getLatest();
+ $cachedRevId = $value->getCacheRevisionId();
+ wfDebugLog( "ParserCache",
+ "ParserOutput key is for an old revision, latest $revId, cached $cachedRevId\n"
+ );
+ $value = false;
+ } elseif (
+ Hooks::run( 'RejectParserCacheValue', [ $value, $wikiPage, $popts ] ) === false
+ ) {
+ wfIncrStats( 'pcache.miss.rejected' );
+ wfDebugLog( "ParserCache",
+ "ParserOutput key valid, but rejected by RejectParserCacheValue hook handler.\n"
+ );
+ $value = false;
+ } else {
+ wfIncrStats( "pcache.hit" );
}
- wfProfileOut( $fname );
return $value;
}
- function save( $parserOutput, &$article, $popts ){
- global $wgParserCacheExpireTime;
- $key = $this->getKey( $article, $popts );
+ /**
+ * @param ParserOutput $parserOutput
+ * @param WikiPage $page
+ * @param ParserOptions $popts
+ * @param string $cacheTime Time when the cache was generated
+ * @param int $revId Revision ID that was parsed
+ */
+ public function save( $parserOutput, $page, $popts, $cacheTime = null, $revId = null ) {
+ $expire = $parserOutput->getCacheExpiry();
+ if ( $expire > 0 && !$this->mMemc instanceof EmptyBagOStuff ) {
+ $cacheTime = $cacheTime ?: wfTimestampNow();
+ if ( !$revId ) {
+ $revision = $page->getRevision();
+ $revId = $revision ? $revision->getId() : null;
+ }
+
+ $optionsKey = new CacheTime;
+ $optionsKey->mUsedOptions = $parserOutput->getUsedOptions();
+ $optionsKey->updateCacheExpiry( $expire );
- if( $parserOutput->getCacheTime() != -1 ) {
+ $optionsKey->setCacheTime( $cacheTime );
+ $parserOutput->setCacheTime( $cacheTime );
+ $optionsKey->setCacheRevisionId( $revId );
+ $parserOutput->setCacheRevisionId( $revId );
- $now = wfTimestampNow();
- $parserOutput->setCacheTime( $now );
+ $parserOutputKey = $this->getParserOutputKey( $page,
+ $popts->optionsHash( $optionsKey->mUsedOptions, $page->getTitle() ) );
// Save the timestamp so that we don't have to load the revision row on view
- $parserOutput->mTimestamp = $article->getTimestamp();
+ $parserOutput->setTimestamp( $page->getTimestamp() );
- $parserOutput->mText .= "\n<!-- Saved in parser cache with key $key and timestamp $now -->\n";
- wfDebug( "Saved in parser cache with key $key and timestamp $now\n" );
+ $msg = "Saved in parser cache with key $parserOutputKey" .
+ " and timestamp $cacheTime" .
+ " and revision id $revId" .
+ "\n";
- if( $parserOutput->containsOldMagic() ){
- $expire = 3600; # 1 hour
- } else {
- $expire = $wgParserCacheExpireTime;
- }
- $this->mMemc->set( $key, $parserOutput, $expire );
+ $parserOutput->mText .= "\n<!-- $msg -->\n";
+ wfDebug( $msg );
- } else {
+ // Save the parser output
+ $this->mMemc->set( $parserOutputKey, $parserOutput, $expire );
+
+ // ...and its pointer
+ $this->mMemc->set( $this->getOptionsKey( $page ), $optionsKey, $expire );
+
+ Hooks::run(
+ 'ParserCacheSaveComplete',
+ [ $this, $parserOutput, $page->getTitle(), $popts, $revId ]
+ );
+ } elseif ( $expire <= 0 ) {
wfDebug( "Parser output was marked as uncacheable and has not been saved.\n" );
}
}
+ /**
+ * Get the backend BagOStuff instance that
+ * powers the parser cache
+ *
+ * @since 1.30
+ * @return BagOStuff
+ */
+ public function getCacheStorage() {
+ return $this->mMemc;
+ }
}
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