removed debug statement

[lhc/web/wiklou.git] / includes / BacklinkCache.php

diff --git a/includes/BacklinkCache.php b/includes/BacklinkCache.php
index e445145..02b0f17 100644 (file)
--- a/includes/BacklinkCache.php
+++ b/includes/BacklinkCache.php
@@ -1,10 +1,9 @@
 <?php
-
 /**
  * Class for fetching backlink lists, approximate backlink counts and partitions.
  * Instances of this class should typically be fetched with $title->getBacklinkCache().
  *
- * Ideally you should only get your backlinks from here when you think there is some 
+ * Ideally you should only get your backlinks from here when you think there is some
  * advantage in caching them. Otherwise it's just a waste of memory.
  */
 class BacklinkCache {
@@ -22,6 +21,14 @@ class BacklinkCache {
                $this->title = $title;
        }
 
+       /**
+        * Serialization handler, diasallows to serialize the database to prevent
+        * failures after this class is deserialized from cache with dead DB connection.
+        */
+       function __sleep() {
+               return array( 'partitionCache', 'fullResultCache', 'title' );
+       }
+
        /**
         * Clear locally stored data
         */
@@ -42,6 +49,7 @@ class BacklinkCache {
                if ( !isset( $this->db ) ) {
                        $this->db = wfGetDB( DB_SLAVE );
                }
+
                return $this->db;
        }
 
@@ -56,21 +64,25 @@ class BacklinkCache {
                wfProfileIn( __METHOD__ );
 
                $fromField = $this->getPrefix( $table ) . '_from';
+
                if ( $startId || $endId ) {
                        // Partial range, not cached
-                       wfDebug( __METHOD__.": from DB (uncacheable range)\n" );
+                       wfDebug( __METHOD__ . ": from DB (uncacheable range)\n" );
                        $conds = $this->getConditions( $table );
+
                        // Use the from field in the condition rather than the joined page_id,
                        // because databases are stupid and don't necessarily propagate indexes.
                        if ( $startId ) {
                                $conds[] = "$fromField >= " . intval( $startId );
                        }
+
                        if ( $endId ) {
                                $conds[] = "$fromField <= " . intval( $endId );
                        }
-                       $res = $this->getDB()->select( 
+
+                       $res = $this->getDB()->select(
                                array( $table, 'page' ),
-                               array( 'page_namespace', 'page_title', 'page_id'),
+                               array( 'page_namespace', 'page_title', 'page_id' ),
                                $conds,
                                __METHOD__,
                                array(
@@ -78,13 +90,14 @@ class BacklinkCache {
                                        'ORDER BY' => $fromField
                                ) );
                        $ta = TitleArray::newFromResult( $res );
+
                        wfProfileOut( __METHOD__ );
                        return $ta;
                }
 
                if ( !isset( $this->fullResultCache[$table] ) ) {
-                       wfDebug( __METHOD__.": from DB\n" );
-                       $res = $this->getDB()->select( 
+                       wfDebug( __METHOD__ . ": from DB\n" );
+                       $res = $this->getDB()->select(
                                array( $table, 'page' ),
                                array( 'page_namespace', 'page_title', 'page_id' ),
                                $this->getConditions( $table ),
@@ -95,7 +108,9 @@ class BacklinkCache {
                                ) );
                        $this->fullResultCache[$table] = $res;
                }
+
                $ta = TitleArray::newFromResult( $this->fullResultCache[$table] );
+
                wfProfileOut( __METHOD__ );
                return $ta;
        }
@@ -111,6 +126,7 @@ class BacklinkCache {
                        'templatelinks' => 'tl',
                        'redirect' => 'rd',
                );
+
                if ( isset( $prefixes[$table] ) ) {
                        return $prefixes[$table];
                } else {
@@ -123,6 +139,7 @@ class BacklinkCache {
         */
        protected function getConditions( $table ) {
                $prefix = $this->getPrefix( $table );
+
                switch ( $table ) {
                        case 'pagelinks':
                        case 'templatelinks':
@@ -134,13 +151,13 @@ class BacklinkCache {
                                );
                                break;
                        case 'imagelinks':
-                               $conds = array( 
+                               $conds = array(
                                        'il_to' => $this->title->getDBkey(),
                                        'page_id=il_from'
                                );
                                break;
                        case 'categorylinks':
-                               $conds = array( 
+                               $conds = array(
                                        'cl_to' => $this->title->getDBkey(),
                                        'page_id=cl_from',
                                );
@@ -148,6 +165,7 @@ class BacklinkCache {
                        default:
                                throw new MWException( "Invalid table \"$table\" in " . __CLASS__ );
                }
+
                return $conds;
        }
 
@@ -158,11 +176,14 @@ class BacklinkCache {
                if ( isset( $this->fullResultCache[$table] ) ) {
                        return $this->fullResultCache[$table]->numRows();
                }
+
                if ( isset( $this->partitionCache[$table] ) ) {
                        $entry = reset( $this->partitionCache[$table] );
                        return $entry['numRows'];
                }
+
                $titleArray = $this->getLinks( $table );
+
                return $titleArray->count();
        }
 
@@ -178,44 +199,58 @@ class BacklinkCache {
        public function partition( $table, $batchSize ) {
                // Try cache
                if ( isset( $this->partitionCache[$table][$batchSize] ) ) {
-                       wfDebug( __METHOD__.": got from partition cache\n" );
+                       wfDebug( __METHOD__ . ": got from partition cache\n" );
                        return $this->partitionCache[$table][$batchSize]['batches'];
                }
+
                $this->partitionCache[$table][$batchSize] = false;
                $cacheEntry =& $this->partitionCache[$table][$batchSize];
 
                // Try full result cache
                if ( isset( $this->fullResultCache[$table] ) ) {
                        $cacheEntry = $this->partitionResult( $this->fullResultCache[$table], $batchSize );
-                       wfDebug( __METHOD__.": got from full result cache\n" );
+                       wfDebug( __METHOD__ . ": got from full result cache\n" );
+
                        return $cacheEntry['batches'];
                }
+
                // Try memcached
                global $wgMemc;
-               $memcKey = wfMemcKey( 'backlinks', md5( $this->title->getPrefixedDBkey() ), 
-                       $table, $batchSize );
+
+               $memcKey = wfMemcKey(
+                       'backlinks',
+                       md5( $this->title->getPrefixedDBkey() ),
+                       $table,
+                       $batchSize
+               );
+
                $memcValue = $wgMemc->get( $memcKey );
+
                if ( is_array( $memcValue ) ) {
                        $cacheEntry = $memcValue;
-                       wfDebug( __METHOD__.": got from memcached $memcKey\n" );
+                       wfDebug( __METHOD__ . ": got from memcached $memcKey\n" );
+
                        return $cacheEntry['batches'];
                }
+
                // Fetch from database
                $this->getLinks( $table );
                $cacheEntry = $this->partitionResult( $this->fullResultCache[$table], $batchSize );
                // Save to memcached
                $wgMemc->set( $memcKey, $cacheEntry, self::CACHE_EXPIRY );
-               wfDebug( __METHOD__.": got from database\n" );
+
+               wfDebug( __METHOD__ . ": got from database\n" );
                return $cacheEntry['batches'];
        }
 
-       /** 
+       /**
         * Partition a DB result with backlinks in it into batches
         */
        protected function partitionResult( $res, $batchSize ) {
                $batches = array();
                $numRows = $res->numRows();
                $numBatches = ceil( $numRows / $batchSize );
+
                for ( $i = 0; $i < $numBatches; $i++ ) {
                        if ( $i == 0  ) {
                                $start = false;
@@ -225,6 +260,7 @@ class BacklinkCache {
                                $row = $res->fetchObject();
                                $start = $row->page_id;
                        }
+
                        if ( $i == $numBatches - 1 ) {
                                $end = false;
                        } else {
@@ -236,11 +272,12 @@ class BacklinkCache {
 
                        # Sanity check order
                        if ( $start && $end && $start > $end ) {
-                               throw new MWException( __METHOD__.': Internal error: query result out of order' );
+                               throw new MWException( __METHOD__ . ': Internal error: query result out of order' );
                        }
 
                        $batches[] = array( $start, $end );
                }
+
                return array( 'numRows' => $numRows, 'batches' => $batches );
        }
 }