From 5ac27d708b1ac04e42dd6b11c234d8f65a18905d Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 4 Dec 2013 00:27:23 -0800
Subject: [PATCH] Made Title cache use MapCacheLRU

Change-Id: I913238adc2b8471e247df77150cfd772da1ac3f4
---
 includes/Title.php             | 31 +++++++++++++++++--------------
 includes/cache/MapCacheLRU.php | 11 ++++++++++-
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/includes/Title.php b/includes/Title.php
index 2961500531..a29999d36b 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -31,10 +31,8 @@
  * @internal documentation reviewed 15 Mar 2010
  */
 class Title {
-	/** @name Static cache variables */
-	// @{
-	static private $titleCache = array();
-	// @}
+	/** @var MapCacheLRU */
+	static private $titleCache = null;
 
 	/**
 	 * Title::newFromText maintains a cache to avoid expensive re-normalization of
@@ -130,6 +128,8 @@ class Title {
 			throw new MWException( 'Title::newFromText given an object' );
 		}
 
+		$cache = self::getTitleCache();
+
 		/**
 		 * Wiki pages often contain multiple links to the same page.
 		 * Title normalization and parsing can become expensive on
@@ -138,8 +138,8 @@ class Title {
 		 *
 		 * In theory these are value objects and won't get changed...
 		 */
-		if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
-			return Title::$titleCache[$text];
+		if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
+			return $cache->get( $text );
 		}
 
 		# Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
@@ -149,16 +149,9 @@ class Title {
 		$t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 		$t->mDefaultNamespace = $defaultNamespace;
 
-		static $cachedcount = 0;
 		if ( $t->secureAndSplit() ) {
 			if ( $defaultNamespace == NS_MAIN ) {
-				if ( $cachedcount >= self::CACHE_MAX ) {
-					# Avoid memory leaks on mass operations...
-					Title::$titleCache = array();
-					$cachedcount = 0;
-				}
-				$cachedcount++;
-				Title::$titleCache[$text] =& $t;
+				$cache->set( $text, $t );
 			}
 			return $t;
 		} else {
@@ -200,6 +193,16 @@ class Title {
 		}
 	}
 
+	/**
+	 * @return MapCacheLRU
+	 */
+	private static function getTitleCache() {
+		if ( self::$titleCache == null ) {
+			self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
+		}
+		return self::$titleCache;
+	}
+
 	/**
 	 * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 	 * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
diff --git a/includes/cache/MapCacheLRU.php b/includes/cache/MapCacheLRU.php
index 3539d8fca2..c66461e86f 100644
--- a/includes/cache/MapCacheLRU.php
+++ b/includes/cache/MapCacheLRU.php
@@ -66,13 +66,22 @@ class MapCacheLRU {
 		$this->cache[$key] = $value;
 	}
 
+	/**
+	 * Check if a key exists
+	 *
+	 * @param $key string
+	 * @return bool
+	 */
+	public function has( $key ) {
+		return isset( $this->cache[$key] );
+	}
+
 	/**
 	 * Get the value for a key.
 	 * This returns null if the key is not set.
 	 * If the item is already set, it will be pushed to the top of the cache.
 	 *
 	 * @param $key string
-	 * @param $prop string
 	 * @return mixed
 	 */
 	public function get( $key ) {
-- 
2.20.1