Cache: Add APC and XCache to global cache handler

lib/cache.php

@@ -12,7 +12,17 @@ class OC_Cache {
 
 	static public function getGlobalCache() {
 		if (!self::$global_cache) {
+			$fast_cache = null;
+			if (!$fast_cache && function_exists('xcache_set')) {
+				$fast_cache = new OC_Cache_XCache(true);
+			}
+			if (!$fast_cache && function_exists('apc_store')) {
+				$fast_cache = new OC_Cache_APC(true);
+			}
 			self::$global_cache = new OC_Cache_FileGlobal();
+			if ($fast_cache) {
+				self::$global_cache = new OC_Cache_Broker($fast_cache, self::$global_cache);
+			}
 		}
 		return self::$global_cache;
 	}

lib/cache/apc.php

@@ -7,11 +7,20 @@
  */
 
 class OC_Cache_APC {
+	protected $prefix;
+
+	public function __construct($global = false) {
+		$this->prefix = OC_Util::getInstanceId().'/';
+		if (!$global) {
+			$this->prefix .= OC_User::getUser().'/';
+		}
+	}
+
 	/**
 	 * entries in APC gets namespaced to prevent collisions between owncloud instances and users
 	 */
 	protected function getNameSpace() {
-		return OC_Util::getInstanceId().'/'.OC_User::getUser().'/';
+		return $this->prefix;
 	}
 
 	public function get($key) {

lib/cache/xcache.php

@@ -7,11 +7,20 @@
  */
 
 class OC_Cache_XCache {
+	protected $prefix;
+
+	public function __construct($global = false) {
+		$this->prefix = OC_Util::getInstanceId().'/';
+		if (!$global) {
+			$this->prefix .= OC_User::getUser().'/';
+		}
+	}
+
 	/**
 	 * entries in XCache gets namespaced to prevent collisions between owncloud instances and users
 	 */
 	protected function getNameSpace() {
-		return OC_Util::getInstanceId().'/'.OC_User::getUser().'/';
+		return $this->prefix;
 	}
 
 	public function get($key) {