* Respect read-only mode on block removals
[lhc/web/wiklou.git] / includes / ParserCache.php
index 59522e4..4447869 100644 (file)
@@ -1,13 +1,24 @@
 <?php
 /**
  *
+ * @package MediaWiki
  */
 
 /**
  *
+ * @package MediaWiki
  */
-class ParserCache
-{
+class ParserCache {
+       /**
+        * Setup a cache pathway with a given back-end storage mechanism.
+        * May be a memcached client or a BagOStuff derivative.
+        *
+        * @param object $memCached
+        */
+       function ParserCache( &$memCached ) {
+               $this->mMemc =& $memCached;
+       }
+       
        function getKey( &$article, &$user ) {
                global $wgDBname;
                $hash = $user->getPageRenderingHash();
@@ -17,31 +28,39 @@ class ParserCache
        }
        
        function get( &$article, &$user ) {
-               global $wgMemc, $wgCacheEpoch;
+               global $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 ) {
+               $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->getCacheTime() <= $touched || $cacheTime < $wgCacheEpoch ) {
+                       if ( !$canCache || $value->expired( $touched ) ) {
                                if ( !$canCache ) {
+                                       $this->incrStats( "pcache_miss_invalid" );
                                        wfDebug( "Invalid cached redirect, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
                                } else {
+                                       $this->incrStats( "pcache_miss_expired" );
                                        wfDebug( "Key expired, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
                                }
-                               $wgMemc->delete( $key );
+                               $this->mMemc->delete( $key );
                                $value = false;
+
+                       } else {
+                               $this->incrStats( "pcache_hit" );
                        }
                } else {
+                       wfDebug( "Parser cache miss.\n" );
+                       $this->incrStats( "pcache_miss_absent" );
                        $value = false;
                }
 
@@ -50,20 +69,26 @@ class ParserCache
        }
        
        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";
+               wfDebug( "Saved in parser cache with key $key and timestamp $now\n" );
 
                if( $parserOutput->containsOldMagic() ){
                        $expire = 3600; # 1 hour
                } else {
                        $expire = 86400; # 1 day
                }
+               $this->mMemc->set( $key, $parserOutput, $expire );
+       }
 
-               $wgMemc->set( $key, $parserOutput, $expire );
+       function incrStats( $key ) {
+               global $wgDBname, $wgMemc;
+               $key = "$wgDBname:stats:$key";
+               if ( is_null( $wgMemc->incr( $key ) ) ) {
+                       $wgMemc->add( $key, 1 );
+               }
        }
 }