]> scripts.mit.edu Git - autoinstallsdev/mediawiki.git/blobdiff - includes/parser/ParserCache.php
MediaWiki 1.30.2
[autoinstallsdev/mediawiki.git] / includes / parser / ParserCache.php
index 1e028ae534ba6cacfa105cf5193164d7df3c27de..c680129934ffdebd845e02ed7bcf0322e396eadc 100644 (file)
 /**
  * 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;
-       const try116cache = false; /* Only useful $wgParserCacheExpireTime after updating to 1.17 */
 
+       /**
+        * 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;
+               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 $memCached Object
+        * 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( $memCached ) {
-               if ( !$memCached ) {
-                       throw new MWException( "Tried to create a ParserCache with an invalid memcached" );
-               }
-               $this->mMemc = $memCached;
+       public function __construct( BagOStuff $cache, $cacheEpoch = '20030516000000' ) {
+               $this->mMemc = $cache;
+               $this->cacheEpoch = $cacheEpoch;
        }
 
+       /**
+        * @param WikiPage $article
+        * @param string $hash
+        * @return mixed|string
+        */
        protected function getParserOutputKey( $article, $hash ) {
                global $wgRequest;
 
                // idhash seem to mean 'page id' + 'rendering hash' (r3710)
-               $pageid = $article->getID();
-               $renderkey = (int)($wgRequest->getVal('action') == 'render');
+               $pageid = $article->getId();
+               $renderkey = (int)( $wgRequest->getVal( 'action' ) == 'render' );
 
-               $key = wfMemcKey( 'pcache', 'idhash', "{$pageid}-{$renderkey}!{$hash}" );
+               $key = $this->mMemc->makeKey( 'pcache', 'idhash', "{$pageid}-{$renderkey}!{$hash}" );
                return $key;
        }
 
-       protected function getOptionsKey( $article ) {
-               $pageid = $article->getID();
-               return wfMemcKey( 'pcache', 'idoptions', "{$pageid}" );
+       /**
+        * @param WikiPage $page
+        * @return mixed|string
+        */
+       protected function getOptionsKey( $page ) {
+               return $this->mMemc->makeKey( 'pcache', 'idoptions', $page->getId() );
+       }
+
+       /**
+        * @param WikiPage $page
+        * @since 1.28
+        */
+       public function deleteOptionsKey( $page ) {
+               $this->mMemc->delete( $this->getOptionsKey( $page ) );
        }
 
        /**
@@ -63,15 +123,22 @@ class ParserCache {
         * $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
         */
-       function getETag( $article, $popts ) {
+       public function getETag( $article, $popts ) {
                return 'W/"' . $this->getParserOutputKey( $article,
-                       $popts->optionsHash( ParserOptions::legacyOptions() ) ) .
+                       $popts->optionsHash( ParserOptions::allCacheVaryingOptions(), $article->getTitle() ) ) .
                                "--" . $article->getTouched() . '"';
        }
 
        /**
         * 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 );
@@ -79,125 +146,214 @@ class ParserCache {
        }
 
        /**
-        * Used to provide a unique id for the PoolCounter.
+        * 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 = true ) {
-               global $wgCacheEpoch;
+       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 ) {
+               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
-               $optionsKey = $this->mMemc->get( $this->getOptionsKey( $article ) );
-               if ( $optionsKey != false ) {
-                       if ( !$useOutdated && $optionsKey->expired( $article->getTouched() ) ) {
-                               wfIncrStats( "pcache_miss_expired" );
+               $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();
-                               wfDebug( "Parser options key expired, touched " . $article->getTouched() . ", epoch $wgCacheEpoch, cached $cacheTime\n" );
+                               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 = $optionsKey->mUsedOptions;
                        wfDebug( "Parser cache options found.\n" );
                } else {
-                       if ( !$useOutdated && !self::try116cache ) {
+                       if ( $useOutdated < self::USE_ANYTHING ) {
                                return false;
                        }
-                       $usedOptions = ParserOptions::legacyOptions();
+                       $usedOptions = ParserOptions::allCacheVaryingOptions();
                }
 
-               return $this->getParserOutputKey( $article, $popts->optionsHash( $usedOptions ) );
+               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 ) {
-               global $wgCacheEpoch;
-               wfProfileIn( __METHOD__ );
-
                $canCache = $article->checkTouched();
                if ( !$canCache ) {
                        // It's a redirect now
-                       wfProfileOut( __METHOD__ );
                        return false;
                }
 
                $touched = $article->getTouched();
 
-               $parserOutputKey = $this->getKey( $article, $popts, $useOutdated );
+               $parserOutputKey = $this->getKey( $article, $popts,
+                       $useOutdated ? self::USE_OUTDATED : self::USE_CURRENT_ONLY
+               );
                if ( $parserOutputKey === false ) {
-                       wfProfileOut( __METHOD__ );
+                       wfIncrStats( 'pcache.miss.absent' );
                        return false;
                }
 
-               $value = $this->mMemc->get( $parserOutputKey );
-               if ( self::try116cache && !$value && strpos( $value, '*' ) !== -1 ) {
-                       wfDebug( "New format parser cache miss.\n" );
-                       $parserOutputKey = $this->getParserOutputKey( $article, $popts->optionsHash( ParserOptions::legacyOptions() ) );
-                       $value = $this->mMemc->get( $parserOutputKey );
-               }
+               $casToken = null;
+               /** @var ParserOutput $value */
+               $value = $this->mMemc->get( $parserOutputKey, $casToken, BagOStuff::READ_VERIFIED );
                if ( !$value ) {
-                       wfDebug( "Parser cache miss.\n" );
-                       wfIncrStats( "pcache_miss_absent" );
-                       wfProfileOut( __METHOD__ );
+                       wfDebug( "ParserOutput cache miss.\n" );
+                       wfIncrStats( "pcache.miss.absent" );
                        return false;
                }
 
-               wfDebug( "Found.\n" );
+               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" );
+                       wfIncrStats( "pcache.miss.expired" );
                        $cacheTime = $value->getCacheTime();
-                       wfDebug( "ParserOutput key expired, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
+                       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 {
-                       if ( isset( $value->mTimestamp ) ) {
-                               $article->mTimestamp = $value->mTimestamp;
-                       }
-                       wfIncrStats( "pcache_hit" );
+                       wfIncrStats( "pcache.hit" );
                }
 
-               wfProfileOut( __METHOD__ );
                return $value;
        }
 
-
-       public function save( $parserOutput, $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 ) {
-                       $now = wfTimestampNow();
+               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 );
 
-                       $optionsKey->setCacheTime( $now );
-                       $parserOutput->setCacheTime( $now );
-
-                       $optionsKey->setContainsOldMagic( $parserOutput->containsOldMagic() );
+                       $optionsKey->setCacheTime( $cacheTime );
+                       $parserOutput->setCacheTime( $cacheTime );
+                       $optionsKey->setCacheRevisionId( $revId );
+                       $parserOutput->setCacheRevisionId( $revId );
 
-                       $parserOutputKey = $this->getParserOutputKey( $article, $popts->optionsHash( $optionsKey->mUsedOptions ) );
+                       $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() );
+
+                       $msg = "Saved in parser cache with key $parserOutputKey" .
+                               " and timestamp $cacheTime" .
+                               " and revision id $revId" .
+                               "\n";
 
-                       $parserOutput->mText .= "\n<!-- Saved in parser cache with key $parserOutputKey and timestamp $now -->\n";
-                       wfDebug( "Saved in parser cache with key $parserOutputKey and timestamp $now\n" );
+                       $parserOutput->mText .= "\n<!-- $msg -->\n";
+                       wfDebug( $msg );
 
                        // Save the parser output
                        $this->mMemc->set( $parserOutputKey, $parserOutput, $expire );
 
                        // ...and its pointer
-                       $this->mMemc->set( $this->getOptionsKey( $article ), $optionsKey, $expire );
-               } else {
+                       $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;
+       }
 }