ParserCache.php

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<?php

class ParserCache
{
        function getKey( &$article, &$user ) {
                global $wgDBname;
                $hash = $user->getPageRenderingHash();
                $pageid = intval( $article->getID() );
                $key = "$wgDBname:pcache:idhash:$pageid-$hash";
                return $key;
        }
        
        function get( &$article, &$user ) {
                global $wgMemc, $wgCacheEpoch;
                $fname = "ParserCache::get";
                wfProfileIn( $fname );

                $hash = $user->getPageRenderingHash();
                $pageid = intval( $article->getID() );
                $key = $this->getKey( $article, $user );
                wfDebug( "Trying parser cache $key\n" );
                $value = $wgMemc->get( $key );
                if ( $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->getCacheTime() <= $touched || $cacheTime < $wgCacheEpoch ) {
                                if ( !$canCache ) {
                                        wfDebug( "Invalid cached redirect, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
                                } else {
                                        wfDebug( "Key expired, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
                                }
                                $wgMemc->delete( $key );
                                $value = false;
                        }
                } else {
                        $value = false;
                }

                wfProfileOut( $fname );
                return $value;
        }
        
        function save( $parserOutput, &$article, &$user ){
                global $wgMemc;

                $key = $this->getKey( $article, $user );
                $now = wfTimestampNow();
                $parserOutput->setCacheTime( $now );
                $parserOutput->mText .= "\n<!-- Saved in parser cache with key $key and timestamp $now -->\n";

                if( $parserOutput->containsOldMagic() ){
                        $expire = 3600; # 1 hour
                } else {
                        $expire = 86400; # 1 day
                }

                $wgMemc->set( $key, $parserOutput, $expire );
        }
}


?>

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