includes/ParserCache.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  * @subpackage Cache
   6  */
   7
   8 /**
   9  *
  10  * @package MediaWiki
  11  */
  12 class ParserCache {
  13         /**
  14          * Setup a cache pathway with a given back-end storage mechanism.
  15          * May be a memcached client or a BagOStuff derivative.
  16          *
  17          * @param object $memCached
  18          */
  19         function ParserCache( &$memCached ) {
  20                 $this->mMemc =& $memCached;
  21         }
  22
  23         function getKey( &$article, &$user ) {
  24                 global $wgDBname, $action;
  25                 $hash = $user->getPageRenderingHash();
  26                 if( !$article->mTitle->userCanEdit() ) {
  27                         // section edit links are suppressed even if the user has them on
  28                         $edit = '!edit=0';
  29                 } else {
  30                         $edit = '';
  31                 }
  32                 $pageid = intval( $article->getID() );
  33                 $renderkey = (int)($action == 'render');
  34                 $key = "$wgDBname:pcache:idhash:$pageid-$renderkey!$hash$edit";
  35                 return $key;
  36         }
  37
  38         function getETag( &$article, &$user ) {
  39                 return 'W/"' . $this->getKey($article, $user) . "--" . $article->mTouched. '"';
  40         }
  41
  42         function get( &$article, &$user ) {
  43                 global $wgCacheEpoch;
  44                 $fname = 'ParserCache::get';
  45                 wfProfileIn( $fname );
  46
  47                 $hash = $user->getPageRenderingHash();
  48                 $pageid = intval( $article->getID() );
  49                 $key = $this->getKey( $article, $user );
  50
  51                 wfDebug( "Trying parser cache $key\n" );
  52                 $value = $this->mMemc->get( $key );
  53                 if ( is_object( $value ) ) {
  54                         wfDebug( "Found.\n" );
  55                         # Delete if article has changed since the cache was made
  56                         $canCache = $article->checkTouched();
  57                         $cacheTime = $value->getCacheTime();
  58                         $touched = $article->mTouched;
  59                         if ( !$canCache || $value->expired( $touched ) ) {
  60                                 if ( !$canCache ) {
  61                                         wfIncrStats( "pcache_miss_invalid" );
  62                                         wfDebug( "Invalid cached redirect, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
  63                                 } else {
  64                                         wfIncrStats( "pcache_miss_expired" );
  65                                         wfDebug( "Key expired, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
  66                                 }
  67                                 $this->mMemc->delete( $key );
  68                                 $value = false;
  69
  70                         } else {
  71                                 wfIncrStats( "pcache_hit" );
  72                         }
  73                 } else {
  74                         wfDebug( "Parser cache miss.\n" );
  75                         wfIncrStats( "pcache_miss_absent" );
  76                         $value = false;
  77                 }
  78
  79                 wfProfileOut( $fname );
  80                 return $value;
  81         }
  82
  83         function save( $parserOutput, &$article, &$user ){
  84                 $key = $this->getKey( $article, $user );
  85                 $now = wfTimestampNow();
  86                 $parserOutput->setCacheTime( $now );
  87                 $parserOutput->mText .= "\n<!-- Saved in parser cache with key $key and timestamp $now -->\n";
  88                 wfDebug( "Saved in parser cache with key $key and timestamp $now\n" );
  89
  90                 if( $parserOutput->containsOldMagic() ){
  91                         $expire = 3600; # 1 hour
  92                 } else {
  93                         $expire = 86400; # 1 day
  94                 }
  95                 $this->mMemc->set( $key, $parserOutput, $expire );
  96         }
  97 }
  98
  99
 100 ?>