Added option to connect through unix socket in redis cache driver
diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index 40823fc..8daed8b 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -44,6 +44,7 @@
 	 * @var	array
 	 */
 	protected static $_default_config = array(
+		'socket_type' => 'tcp',
 		'host' => '127.0.0.1',
 		'password' => NULL,
 		'port' => 6379,
@@ -200,7 +201,13 @@
 
 		try
 		{
-			$this->_redis->connect($config['host'], $config['port'], $config['timeout']);
+			if ($config['socket_type'] === 'unix')
+			{
+				$v = $this->_redis->connect($config['socket']);
+			} else // tcp socket
+			{
+				$this->_redis->connect($config['host'], $config['port'], $config['timeout']);
+			}
 		}
 		catch (RedisException $e)
 		{