Memcache: Add delete method.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2489 44740490-163a-0410-bde0-09ae8108e29a

lib/SimpleSAML/Memcache.php

@@ -137,6 +137,21 @@ class SimpleSAML_Memcache {
 	}
 
 
+	/**
+	 * Delete a key-value pair from the memcache servers.
+	 *
+	 * @param string $key  The key we should delete.
+	 */
+	public static function delete($key) {
+		assert('is_string($key)');
+
+		/* Store this object to all groups of memcache servers. */
+		foreach(self::getMemcacheServers() as $server) {
+			$server->delete($key);
+		}
+	}
+
+
 	/**
 	 * This function adds a server from the 'memcache_store.servers'
 	 * configuration option to a Memcache object.