Initial version of new Session library

7 files changed, 1255 insertions, 1488 deletions

diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index 905352bb3..0d444e8ca 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -29,729 +29,701 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 /**
  * CodeIgniter Session Class
  *
- * The user interface defined by EllisLabs, now with puggable drivers to manage different storage mechanisms.
- * By default, the cookie session driver will load, but the 'sess_driver' config/param item (see above) can be
- * used to specify the 'native' driver, or any other you might create.
- * Once loaded, this driver setup is a drop-in replacement for the former CI_Session library, taking its place as the
- * 'session' member of the global controller framework (e.g.: $CI->session or $this->session).
- * In keeping with the CI_Driver methodology, multiple drivers may be loaded, although this might be a bit confusing.
- * The CI_Session library class keeps track of the most recently loaded driver as "current" to call for driver methods.
- * Ideally, one driver is loaded and all calls go directly through the main library interface. However, any methods
- * called through the specific driver will switch the "current" driver to itself before invoking the library method
- * (which will then call back into the driver for low-level operations). So, alternation between two drivers can be
- * achieved by specifying which driver to use for each call (e.g.: $this->session->native->set_userdata('foo', 'bar');
- * $this->session->cookie->userdata('foo'); $this->session->native->unset_userdata('foo');). Notice in the previous
- * example that the _native_ userdata value 'foo' would be set to 'bar', which would NOT be returned by the call for
- * the _cookie_ userdata 'foo', nor would the _cookie_ value be unset by the call to unset the _native_ 'foo' value.
- *
  * @package		CodeIgniter
  * @subpackage	Libraries
  * @category	Sessions
- * @author		EllisLab Dev Team
+ * @author		Andrey Andreev
  * @link		http://codeigniter.com/user_guide/libraries/sessions.html
  */
-class CI_Session extends CI_Driver_Library {
-
-	/**
-	 * Initialization parameters
-	 *
-	 * @var	array
-	 */
-	public $params = array();
-
-	/**
-	 * Valid drivers list
-	 *
-	 * @var	array
-	 */
-	public $valid_drivers = array('native',	'cookie');
+class CI_Session {
 
-	/**
-	 * Current driver in use
-	 *
-	 * @var	string
-	 */
-	public $current = NULL;
-
-	/**
-	 * User data
-	 *
-	 * @var	array
-	 */
-	protected $userdata = array();
-
-	// ------------------------------------------------------------------------
-
-	const FLASHDATA_KEY = 'flash';
-	const FLASHDATA_NEW = ':new:';
-	const FLASHDATA_OLD = ':old:';
-	const FLASHDATA_EXP = ':exp:';
-	const EXPIRATION_KEY = '__expirations';
-	const TEMP_EXP_DEF = 300;
+	protected $_driver = 'files';
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * CI_Session constructor
-	 *
-	 * The constructor loads the configured driver ('sess_driver' in config.php or as a parameter), running
-	 * routines in its constructor, and manages flashdata aging.
+	 * Class constructor
 	 *
-	 * @param	array	Configuration parameters
+	 * @param	array	$params	Configuration parameters
 	 * @return	void
 	 */
 	public function __construct(array $params = array())
 	{
-		$_config =& get_instance()->config;
 
 		// No sessions under CLI
 		if (is_cli())
 		{
+			log_message('debug', 'Session: Initialization under CLI aborted.');
 			return;
 		}
-
-		log_message('debug', 'CI_Session Class Initialized');
-
-		// Add possible extra entries to our valid drivers list
-		$drivers = isset($params['sess_valid_drivers']) ? $params['sess_valid_drivers'] : $_config->item('sess_valid_drivers');
-		if ( ! empty($drivers))
+		elseif ((bool) ini_get('session.auto_start'))
 		{
-			$drivers = array_map('strtolower', (array) $drivers);
-			$this->valid_drivers = array_merge($this->valid_drivers, array_diff($drivers, $this->valid_drivers));
+			log_message('error', 'Session: session.auto_start is enabled in php.ini. Aborting.');
+			return;
+		}
+		elseif ( ! empty($params['driver']))
+		{
+			$this->_driver = $params['driver'];
+			unset($params['driver']);
 		}
 
-		// Get driver to load
-		$driver = isset($params['sess_driver']) ? $params['sess_driver'] : $_config->item('sess_driver');
-		if ( ! $driver)
+		if (($class = $this->_ci_load_classes($this->_driver)) === FALSE)
 		{
-			log_message('debug', "Session: No driver name is configured, defaulting to 'cookie'.");
-			$driver = 'cookie';
+			return;
 		}
 
-		if ( ! in_array($driver, $this->valid_drivers))
+		$class = new $class($params);
+		if ($class instanceof SessionHandlerInterface)
 		{
-			log_message('error', 'Session: Configured driver name is not valid, aborting.');
+			if (is_php('5.4'))
+			{
+				session_set_save_handler($class, TRUE);
+			}
+			else
+			{
+				session_set_save_handler(
+					array($class, 'open'),
+					array($class, 'close'),
+					array($class, 'read'),
+					array($class, 'write'),
+					array($class, 'destroy'),
+					array($class, 'gc')
+				);
+
+				register_shutdown_function('session_write_close');
+			}
+		}
+		else
+		{
+			log_message('error', "Session: Driver '".$this->_driver."' doesn't implement SessionHandlerInterface. Aborting.");
 			return;
 		}
 
-		// Save a copy of parameters in case drivers need access
-		$this->params = $params;
+		session_start();
+		$this->_ci_init_vars();
 
-		// Load driver and get array reference
-		$this->load_driver($driver);
+		log_message('debug', "Session: Class initialized using '".$this->_driver."' driver.");
+	}
 
-		// Delete 'old' flashdata (from last request)
-		$this->_flashdata_sweep();
+	// ------------------------------------------------------------------------
 
-		// Mark all new flashdata as old (data will be deleted before next request)
-		$this->_flashdata_mark();
+	protected function _ci_load_classes($driver)
+	{
+		// PHP 5.4 compatibility
+		interface_exists('SessionHandlerInterface', FALSE) OR require_once(BASEPATH.'libraries/Session/SessionHandlerInterface.php');
 
-		// Delete expired tempdata
-		$this->_tempdata_sweep();
+		$prefix = config_item('subclass_prefix');
 
-		log_message('debug', 'CI_Session routines successfully run');
-	}
+		if ( ! class_exists('CI_Session_driver', FALSE))
+		{
+			if (file_exists($file_path = APPPATH.'libraries/Session/Session_driver.php') OR file_exists($file_path = BASEPATH.'libraries/Session/Session_driver.php'))
+			{
+				require_once($file_path);
+			}
 
-	// ------------------------------------------------------------------------
+			if (file_exists($file_path = APPPATH.'libraries/Session/'.$prefix.'Session_driver.php'))
+			{
+				require_once($file_path);
+			}
+		}
 
-	/**
-	 * Loads session storage driver
-	 *
-	 * @param	string	Driver classname
-	 * @return	object	Loaded driver object
-	 */
-	public function load_driver($driver)
-	{
-		// Save reference to most recently loaded driver as library default and sync userdata
-		$this->current = parent::load_driver($driver);
-		$this->userdata =& $this->current->get_userdata();
-		return $this->current;
-	}
+		$class = 'Session_'.$driver.'_driver';
 
-	// ------------------------------------------------------------------------
+		if ( ! class_exists('CI_'.$class, FALSE))
+		{
+			if (file_exists($file_path = APPPATH.'libraries/Session/drivers/'.$class.'.php') OR file_exists($file_path = BASEPATH.'libraries/Session/drivers/'.$class.'.php'))
+			{
+				require_once($file_path);
+			}
 
-	/**
-	 * Select default session storage driver
-	 *
-	 * @param	string	Driver name
-	 * @return	void
-	 */
-	public function select_driver($driver)
-	{
-		// Validate driver name
-		$prefix = (string) get_instance()->config->item('subclass_prefix');
-		$child = strtolower(str_replace(array('CI_', $prefix, $this->lib_name.'_'), '', $driver));
-		if (in_array($child, array_map('strtolower', $this->valid_drivers)))
+			if ( ! class_exists('CI_'.$class, FALSE))
+			{
+				log_message('error', "Session: Configured driver '".$driver."' was not found. Aborting.");
+				return FALSE;
+			}
+		}
+
+		if ( ! class_exists($prefix.$class) && file_exists($file_path = APPPATH.'libraries/Session/drivers/'.$prefix.$class.'.php'))
 		{
-			// See if driver is loaded
-			if (isset($this->$child))
+			require_once($file_path);
+			if (class_exists($prefix.$class, FALSE))
 			{
-				// See if driver is already current
-				if ($this->$child !== $this->current)
-				{
-					// Make driver current and sync userdata
-					$this->current = $this->$child;
-					$this->userdata =& $this->current->get_userdata();
-				}
+				return $prefix.$class;
 			}
 			else
 			{
-				// Load new driver
-				$this->load_driver($child);
+				log_message('debug', 'Session: '.$prefix.$class.".php found but it doesn't declare class ".$prefix.$class.'.');
 			}
 		}
+
+		return 'CI_'.$class;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Destroy the current session
+	 * Handle temporary variables
+	 *
+	 * Clears old "flash" data, marks the new one for deletion and handles
+	 * "temp" data deletion.
 	 *
 	 * @return	void
 	 */
-	public function sess_destroy()
+	protected function _ci_init_vars()
 	{
-		// Just call destroy on driver
-		$this->current->sess_destroy();
-	}
+		if ( ! empty($_SESSION['__ci_vars']))
+		{
+			$current_time = time();
 
-	// ------------------------------------------------------------------------
+			foreach ($_SESSION['__ci_vars'] as $key => &$value)
+			{
+				if ($value === 'new')
+				{
+					$_SESSION['__ci_vars'][$key] = 'old';
+				}
+				// Hacky, but 'old' will (implicitly) always be less than time() ;)
+				// DO NOT move this above the 'new' check!
+				elseif ($value < $current_time)
+				{
+					unset($_SESSION[$key], $_SESSION['__ci_vars'][$key]);
+				}
+			}
 
-	/**
-	 * Regenerate the current session
-	 *
-	 * @param	bool	Destroy session data flag (default: false)
-	 * @return	void
-	 */
-	public function sess_regenerate($destroy = FALSE)
-	{
-		// Call regenerate on driver and resync userdata
-		$this->current->sess_regenerate($destroy);
-		$this->userdata =& $this->current->get_userdata();
+			if (empty($_SESSION['__ci_vars']))
+			{
+				unset($_SESSION['__ci_vars']);
+			}
+		}
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Fetch a specific item from the session array
+	 * Mark as flash
 	 *
-	 * @param	string	Item key
-	 * @return	string	Item value or NULL if not found
+	 * @param	mixed	$key	Session data key(s)
+	 * @return	bool
 	 */
-	public function userdata($item = NULL)
+	public function mark_as_flash($key)
 	{
-		if (isset($item))
+		if (is_array($key))
 		{
-			return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
-		}
+			for ($i = 0, $c = count($key); $i < $c; $i++)
+			{
+				if ( ! isset($_SESSION[$key[$i]]))
+				{
+					return FALSE;
+				}
+			}
 
-		return isset($this->userdata) ? $this->userdata : array();
-	}
+			$new = array_fill_keys($key, 'new');
 
-	// ------------------------------------------------------------------------
+			$_SESSION['__ci_vars'] = isset($_SESSION['__ci_vars'])
+				? array_merge($_SESSION['__ci_vars'], $new)
+				: $new;
 
-	/**
-	 * Fetch all session data
-	 *
-	 * @deprecated	3.0.0	Use userdata() with no parameters instead
-	 * @return	array	User data array
-	 */
-	public function all_userdata()
-	{
-		return isset($this->userdata) ? $this->userdata : array();
+			return TRUE;
+		}
+
+		if ( ! isset($_SESSION[$key]))
+		{
+			return FALSE;
+		}
+
+		$_SESSION['__ci_vars'][$key] = 'new';
+		return TRUE;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Add or change data in the "userdata" array
+	 * Get flash keys
 	 *
-	 * @param	mixed	Item name or array of items
-	 * @param	string	Item value or empty string
-	 * @return	void
+	 * @return	array
 	 */
-	public function set_userdata($newdata, $newval = '')
+	public function get_flash_keys()
 	{
-		// Wrap params as array if singular
-		if (is_string($newdata))
+		if ( ! isset($_SESSION['__ci_vars']))
 		{
-			$newdata = array($newdata => $newval);
+			return array();
 		}
 
-		// Set each name/value pair
-		if (count($newdata) > 0)
+		$keys = array();
+		foreach (array_keys($_SESSION['__ci_vars']) as $key)
 		{
-			foreach ($newdata as $key => $val)
-			{
-				$this->userdata[$key] = $val;
-			}
+			is_int($_SESSION['__ci_vars'][$key]) OR $keys[] = $key;
 		}
 
-		// Tell driver data changed
-		$this->current->sess_save();
+		return $keys;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Delete a session variable from the "userdata" array
+	 * Unmark flash
 	 *
-	 * @param	mixed	Item name or array of item names
+	 * @param	mixed	$key	Session data key(s)
 	 * @return	void
 	 */
-	public function unset_userdata($newdata)
+	public function unmark_flash($key)
 	{
-		// Wrap single name as array
-		if (is_string($newdata))
+		if (empty($_SESSION['__ci_vars']))
 		{
-			$newdata = array($newdata => '');
+			return;
 		}
 
-		// Unset each item name
-		if (count($newdata) > 0)
+		is_array($key) OR $key = array($key);
+
+		foreach ($key as $k)
 		{
-			foreach (array_keys($newdata) as $key)
+			if (isset($_SESSION['__ci_vars'][$k]) && ! is_int($_SESSION['__ci_vars'][$k]))
 			{
-				unset($this->userdata[$key]);
+				unset($_SESSION['__ci_vars'][$k]);
 			}
 		}
 
-		// Tell driver data changed
-		$this->current->sess_save();
+		if (empty($_SESSION['__ci_vars']))
+		{
+			unset($_SESSION['__ci_vars']);
+		}
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Determine if an item exists
+	 * Mark as temp
 	 *
-	 * @param	string	Item name
+	 * @param	mixed	$key	Session data key(s)
+	 * @param	int	$ttl	Time-to-live in seconds
 	 * @return	bool
 	 */
-	public function has_userdata($item)
+	public function mark_as_temp($key, $ttl = 300)
 	{
-		return isset($this->userdata[$item]);
+		$ttl += time();
+
+		if (is_array($key))
+		{
+			$temp = array();
+
+			foreach ($key as $k => $v)
+			{
+				// Do we have a key => ttl pair, or just a key?
+				if (is_int($k))
+				{
+					$k = $v;
+					$v = $ttl;
+				}
+				else
+				{
+					$v += time();
+				}
+
+				if ( ! isset($_SESSION[$k]))
+				{
+					return FALSE;
+				}
+
+				$temp[$k] = $ts;
+			}
+
+			$_SESSION['__ci_vars'] = isset($_SESSION['__ci_vars'])
+				? array_merge($_SESSION['__ci_vars'], $temp)
+				: $temp;
+
+			return TRUE;
+		}
+
+		if ( ! isset($_SESSION[$key]))
+		{
+			return FALSE;
+		}
+
+		$_SESSION['__ci_vars'][$key] = $ttl;
+		return TRUE;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Add or change flashdata, only available until the next request
+	 * Get temp keys
 	 *
-	 * @param	mixed	Item name or array of items
-	 * @param	string	Item value or empty string
-	 * @return	void
+	 * @return	array
 	 */
-	public function set_flashdata($newdata, $newval = '')
+	public function get_temp_keys()
 	{
-		// Wrap item as array if singular
-		if (is_string($newdata))
+		if ( ! isset($_SESSION['__ci_vars']))
 		{
-			$newdata = array($newdata => $newval);
+			return array();
 		}
 
-		// Prepend each key name and set value
-		if (count($newdata) > 0)
+		$keys = array();
+		foreach (array_keys($_SESSION['__ci_vars']) as $key)
 		{
-			foreach ($newdata as $key => $val)
-			{
-				$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
-				$this->set_userdata($flashdata_key, $val);
-			}
+			is_int($_SESSION['__ci_vars'][$key]) && $keys[] = $key;
 		}
+
+		return $keys;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Keeps existing flashdata available to next request.
+	 * Unmark flash
 	 *
-	 * @param	mixed	Item key(s)
+	 * @param	mixed	$key	Session data key(s)
 	 * @return	void
 	 */
-	public function keep_flashdata($key)
+	public function unmark_temp($key)
 	{
+		if (empty($_SESSION['__ci_vars']))
+		{
+			return;
+		}
 
-		if (is_array($key))
+		is_array($key) OR $key = array($key);
+
+		foreach ($key as $k)
 		{
-			foreach ($key as $k)
+			if (isset($_SESSION['__ci_vars'][$k]) && is_int($_SESSION['__ci_vars'][$k]))
 			{
-				$this->keep_flashdata($k);
+				unset($_SESSION['__ci_vars'][$k]);
 			}
-
-			return;
 		}
 
-		// 'old' flashdata gets removed. Here we mark all flashdata as 'new' to preserve it from _flashdata_sweep()
-		// Note the function will return NULL if the $key provided cannot be found
-		$old_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key;
-		$value = $this->userdata($old_flashdata_key);
-
-		$new_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
-		$this->set_userdata($new_flashdata_key, $value);
+		if (empty($_SESSION['__ci_vars']))
+		{
+			unset($_SESSION['__ci_vars']);
+		}
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Fetch a specific flashdata item from the session array
+	 * __get()
 	 *
-	 * @param	string	Item key
-	 * @return	string
+	 * @param	string	$key	'session_id' or a session data key
+	 * @return	mixed
 	 */
-	public function flashdata($key = NULL)
+	public function __get($key)
 	{
-		if (isset($key))
+		// Note: Keep this order the same, just in case somebody wants to
+		//       use 'session_id' as a session data key, for whatever reason
+		if (isset($_SESSION[$key]))
 		{
-			return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key);
+			return $_SESSION[$key];
 		}
-
-		// Get our flashdata items from userdata
-		$out = array();
-		foreach ($this->userdata() as $key => $val)
+		elseif ($key === 'session_id')
 		{
-			if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_OLD) !== FALSE)
-			{
-				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_OLD, '', $key);
-				$out[$key] = $val;
-			}
+			return session_id();
 		}
 
-		return $out;
+		return NULL;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Add or change tempdata, only available until expiration
+	 * __set()
 	 *
-	 * @param	mixed	Item name or array of items
-	 * @param	string	Item value or empty string
-	 * @param	int	Item lifetime in seconds or 0 for default
+	 * @param	string	$key	Session data key
+	 * @param	mixed	$value	Session data value
 	 * @return	void
 	 */
-	public function set_tempdata($newdata, $newval = '', $expire = 0)
+	public function __set($key, $value)
 	{
-		// Set expiration time
-		$expire = time() + ($expire ? $expire : self::TEMP_EXP_DEF);
-
-		// Wrap item as array if singular
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => $newval);
-		}
-
-		// Get or create expiration list
-		$expirations = $this->userdata(self::EXPIRATION_KEY);
-		if ( ! $expirations)
-		{
-			$expirations = array();
-		}
+		$_SESSION[$key] = $value;
+	}
 
-		// Prepend each key name and set value
-		if (count($newdata) > 0)
-		{
-			foreach ($newdata as $key => $val)
-			{
-				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
-				$expirations[$tempdata_key] = $expire;
-				$this->set_userdata($tempdata_key, $val);
-			}
-		}
+	// ------------------------------------------------------------------------
 
-		// Update expiration list
-		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	/**
+	 * Session destroy
+	 *
+	 * Legacy CI_Session compatibility method
+	 *
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		session_destroy();
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Delete a temporary session variable from the "userdata" array
+	 * Session regenerate
+	 *
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	mixed	Item name or array of item names
+	 * @param	bool	$destroy	Destroy old session data flag
 	 * @return	void
 	 */
-	public function unset_tempdata($newdata)
+	public function sess_regenerate($destroy = FALSE)
 	{
-		// Get expirations list
-		$expirations = $this->userdata(self::EXPIRATION_KEY);
-		if (empty($expirations))
-		{
-			// Nothing to do
-			return;
-		}
-
-		// Wrap single name as array
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => '');
-		}
+		session_regenerate_id($destroy);
+	}
 
-		// Prepend each item name and unset
-		if (count($newdata) > 0)
-		{
-			foreach (array_keys($newdata) as $key)
-			{
-				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
-				unset($expirations[$tempdata_key]);
-				$this->unset_userdata($tempdata_key);
-			}
-		}
+	// ------------------------------------------------------------------------
 
-		// Update expiration list
-		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	/**
+	 * Get userdata reference
+	 *
+	 * Legacy CI_Session compatibility method
+	 *
+	 * @returns	array
+	 */
+	public function &get_userdata()
+	{
+		return $_SESSION;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Fetch a specific tempdata item from the session array
+	 * Userdata (fetch)
 	 *
-	 * @param	string	Item key
-	 * @return	string
+	 * Legacy CI_Session compatibility method
+	 *
+	 * @param	string	$key	Session data key
+	 * @return	mixed	Session data value or NULL if not found
 	 */
-	public function tempdata($key = NULL)
+	public function userdata($key = NULL)
 	{
 		if (isset($key))
 		{
-			return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key);
+			return isset($_SESSION[$key]) ? $_SESSION[$key] : NULL;
 		}
-
-		// Get our tempdata items from userdata
-		$out = array();
-		foreach ($this->userdata() as $key => $val)
+		elseif (empty($_SESSION))
 		{
-			if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_EXP) !== FALSE)
-			{
-				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_EXP, '', $key);
-				$out[$key] = $val;
-			}
+			return array();
 		}
 
-		return $out;
-	}
+		$userdata = array();
+		$_exclude = array_merge(
+			array('__ci_f', '__ci_t'),
+			$this->get_flash_keys(),
+			$this->get_temp_keys()
+		);
 
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Identifies flashdata as 'old' for removal
-	 * when _flashdata_sweep() runs.
-	 *
-	 * @return	void
-	 */
-	protected function _flashdata_mark()
-	{
-		foreach ($this->userdata() as $name => $value)
+		foreach (array_keys($_SESSION) as $key)
 		{
-			$parts = explode(self::FLASHDATA_NEW, $name);
-			if (count($parts) === 2)
+			if ( ! in_array($key, $_exclude, TRUE))
 			{
-				$this->set_userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1], $value);
-				$this->unset_userdata($name);
+				$userdata[$key] = $_SESSION[$key];
 			}
 		}
+
+		return $userdata;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Removes all flashdata marked as 'old'
+	 * Set userdata
 	 *
+	 * Legacy CI_Session compatibility method
+	 *
+	 * @param	mixed	$data	Session data key or an associative array
+	 * @param	mixed	$value	Value to store
 	 * @return	void
 	 */
-	protected function _flashdata_sweep()
+	public function set_userdata($data, $value = NULL)
 	{
-		$userdata = $this->userdata();
-		foreach (array_keys($userdata) as $key)
+		if (is_array($data))
 		{
-			if (strpos($key, self::FLASHDATA_OLD))
+			foreach ($data as $key => &$value)
 			{
-				$this->unset_userdata($key);
+				$_SESSION[$key] = $value;
 			}
+
+			return;
 		}
+
+		$_SESSION[$data] = $value;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Removes all expired tempdata
+	 * Unset userdata
+	 *
+	 * Legacy CI_Session compatibility method
 	 *
+	 * @param	mixed	$data	Session data key(s)
 	 * @return	void
 	 */
-	protected function _tempdata_sweep()
+	public function unset_userdata($key)
 	{
-		// Get expirations list
-		$expirations = $this->userdata(self::EXPIRATION_KEY);
-		if (empty($expirations))
-		{
-			// Nothing to do
-			return;
-		}
-
-		// Unset expired elements
-		$now = time();
-		$userdata = $this->userdata();
-		foreach (array_keys($userdata) as $key)
+		if (is_array($key))
 		{
-			if (strpos($key, self::FLASHDATA_EXP) && $expirations[$key] < $now)
+			foreach ($key as $k)
 			{
-				unset($expirations[$key]);
-				$this->unset_userdata($key);
+				unset($_SESSION[$key]);
 			}
+
+			return;
 		}
 
-		// Update expiration list
-		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+		unset($_SESSION[$key]);
 	}
 
-}
-
-// ------------------------------------------------------------------------
-
-/**
- * CI_Session_driver Class
- *
- * Extend this class to make a new CI_Session driver.
- * A CI_Session driver basically manages an array of name/value pairs with some sort of storage mechanism.
- * To make a new driver, derive from (extend) CI_Session_driver. Overload the initialize method and read or create
- * session data. Then implement a save handler to write changed data to storage (sess_save), a destroy handler
- * to remove deleted data (sess_destroy), and an access handler to expose the data (get_userdata).
- * Put your driver in the libraries/Session/drivers folder anywhere in the loader paths. This includes the
- * application directory, the system directory, or any path you add with $CI->load->add_package_path().
- * Your driver must be named CI_Session_<name>, and your filename must be Session_<name>.php,
- * preferably also capitalized. (e.g.: CI_Session_foo in libraries/Session/drivers/Session_foo.php)
- * Then specify the driver by setting 'sess_driver' in your config file or as a parameter when loading the CI_Session
- * object. (e.g.: $config['sess_driver'] = 'foo'; OR $CI->load->driver('session', array('sess_driver' => 'foo')); )
- * Already provided are the Native driver, which manages the native PHP $_SESSION array, and
- * the Cookie driver, which manages the data in a browser cookie, with optional extra storage in a database table.
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author		EllisLab Dev Team
- */
-abstract class CI_Session_driver extends CI_Driver {
-
-	/**
-	 * CI Singleton
-	 *
-	 * @see	get_instance()
-	 * @var	object
-	 */
-	protected $CI;
-
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Constructor
+	 * All userdata (fetch)
 	 *
-	 * Gets the CI singleton, so that individual drivers
-	 * don't have to do it separately.
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @return	void
+	 * @return	array	$_SESSION, excluding flash data items
 	 */
-	public function __construct()
+	public function all_userdata()
 	{
-		$this->CI =& get_instance();
+		return $this->userdata();
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Decorate
+	 * Has userdata
 	 *
-	 * Decorates the child with the parent driver lib's methods and properties
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	object	Parent library object
-	 * @return	void
+	 * @param	string	$key	Session data key
+	 * @return	bool
 	 */
-	public function decorate($parent)
+	public function has_userdata($key)
 	{
-		// Call base class decorate first
-		parent::decorate($parent);
-
-		// Call initialize method now that driver has access to $this->_parent
-		$this->initialize();
+		return isset($_SESSION[$key]);
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * __call magic method
+	 * Flashdata (fetch)
 	 *
-	 * Handles access to the parent driver library's methods
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	string	Library method name
-	 * @param	array	Method arguments (default: none)
-	 * @return	mixed
+	 * @param	string	$key	Session data key
+	 * @return	mixed	Session data value or NULL if not found
 	 */
-	public function __call($method, $args = array())
+	public function flashdata($key = NULL)
 	{
-		// Make sure the parent library uses this driver
-		$this->_parent->select_driver(get_class($this));
-		return parent::__call($method, $args);
+		if (isset($key))
+		{
+			return isset($_SESSION['__ci_f'], $_SESSION['__ci_f'][$key], $_SESSION[$key])
+				? $_SESSION[$key]
+				: NULL;
+		}
+
+		$flashdata = array();
+
+		if ( ! empty($_SESSION['__ci_f']))
+		{
+			foreach (array_keys($_SESSION['__ci_f']) as $key)
+			{
+				$flashdata[$key] = $_SESSION[$key];
+			}
+		}
+
+		return $flashdata;
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Initialize driver
+	 * Set flashdata
 	 *
+	 * Legacy CI_Session compatibiliy method
+	 *
+	 * @param	mixed	$data	Session data key or an associative array
+	 * @param	mixed	$value	Value to store
 	 * @return	void
 	 */
-	protected function initialize()
+	public function set_flashdata($data, $value = NULL)
 	{
-		// Overload this method to implement initialization
+		$this->set_userdata($data, $value);
+		$this->mark_as_flash($data);
 	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Save the session data
+	 * Keep flashdata
 	 *
-	 * Data in the array has changed - perform any storage synchronization
-	 * necessary. The child class MUST implement this abstract method!
+	 * Legacy CI_Session compatibility method
 	 *
+	 * @param	mixed	$key	Session data key(s)
 	 * @return	void
 	 */
-	abstract public function sess_save();
+	public function keep_flashdata($key)
+	{
+		$this->mark_as_flash($key);
+	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Destroy the current session
+	 * Temp data (fetch)
 	 *
-	 * Clean up storage for this session - it has been terminated.
-	 * The child class MUST implement this abstract method!
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @return	void
+	 * @param	string	$key	Session data key
+	 * @return	mixed	Session data value or NULL if not found
 	 */
-	abstract public function sess_destroy();
+	public function tempdata($key = NULL)
+	{
+		if (isset($key))
+		{
+			return isset($_SESSION['__ci_t'], $_SESSION['__ci_t'][$key], $_SESSION[$key])
+				? $_SESSION[$key]
+				: NULL;
+		}
+
+		$tempdata = array();
+
+		if ( ! empty($_SESSION['__ci_t']))
+		{
+			foreach (array_keys($_SESSION['__ci_t']) as $key)
+			{
+				$tempdata[$key] = $_SESSION[$key];
+			}
+		}
+
+		return $tempdata;
+	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Regenerate the current session
+	 * Set tempdata
 	 *
-	 * Regenerate the session ID.
-	 * The child class MUST implement this abstract method!
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	bool	Destroy session data flag (default: false)
+	 * @param	mixed	$data	Session data key or an associative array of items
+	 * @param	mixed	$value	Value to store
+	 * @param	int	$ttl	Time-to-live in seconds
 	 * @return	void
 	 */
-	abstract public function sess_regenerate($destroy = FALSE);
+	public function set_tempdata($data, $value = NULL, $ttl = 300)
+	{
+		$this->set_userdata($data, $value);
+		$this->mark_as_temp($data, $ttl);
+	}
 
 	// ------------------------------------------------------------------------
 
 	/**
-	 * Get a reference to user data array
+	 * Unset tempdata
 	 *
-	 * Give array access to the main CI_Session object.
-	 * The child class MUST implement this abstract method!
+	 * Legacy CI_Session compatibility method
 	 *
-	 * @return	array	Reference to userdata
+	 * @param	mixed	$data	Session data key(s)
+	 * @return	void
 	 */
-	abstract public function &get_userdata();
+	public function unset_tempdata($key)
+	{
+		$this->unmark_temp($key);
+	}
 
 }
 
diff --git a/system/libraries/Session/SessionHandlerInterface.php b/system/libraries/Session/SessionHandlerInterface.php
new file mode 100644
index 000000000..7473ff8ec
--- /dev/null
+++ b/system/libraries/Session/SessionHandlerInterface.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * SessionHandlerInterface
+ *
+ * PHP 5.4 compatibility interface
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+interface SessionHandlerInterface {
+
+	public function open($save_path, $name);
+	public function close();
+	public function read($session_id);
+	public function write($session_id, $session_data);
+	public function destroy($session_id);
+	public function gc($maxlifetime);
+}
+
+/* End of file SessionHandlerInterface.php */
+/* Location: ./system/libraries/Session/SessionHandlerInterface.php */
\ No newline at end of file
diff --git a/system/libraries/Session/Session_driver.php b/system/libraries/Session/Session_driver.php
new file mode 100644
index 000000000..c46ca3a34
--- /dev/null
+++ b/system/libraries/Session/Session_driver.php
@@ -0,0 +1,202 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * CodeIgniter Session Driver Class
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+abstract class CI_Session_driver implements SessionHandlerInterface {
+
+	// WARNING! Setting default values to properties will
+	// prevent using the configuration file values.
+
+	/**
+	 * Expiration time
+	 *
+	 * @var	int
+	 */
+	protected $_expiration;
+
+	/**
+	 * Cookie name
+	 *
+	 * @var	string
+	 */
+	protected $_cookie_name;
+
+	/**
+	 * Cookie domain
+	 *
+	 * @var	string
+	 */
+	protected $_cookie_domain;
+
+	/**
+	 * Cookie path
+	 *
+	 * @var	string
+	 */
+	protected $_cookie_path;
+
+	/**
+	 * Cookie secure flag
+	 *
+	 * @var	bool
+	 */
+	protected $_cookie_secure;
+
+	/**
+	 * Cookie HTTP-only flag
+	 *
+	 * @var	bool
+	 */
+	protected $_cookie_httponly;
+
+	/**
+	 * Match IP addresses flag
+	 *
+	 * @var	bool
+	 */
+	protected $_match_ip;
+
+	/**
+	 * Data dash
+	 *
+	 * @var	bool
+	 */
+	protected $_fingerprint;
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params	Configuration parameters
+	 * @return	void
+	 */
+	public function __construct($params)
+	{
+		foreach ($params as $key => &$value)
+		{
+			$key = (strncmp($key, 'sess_', 5) === 0)
+				? substr($key, 4)
+				: '_'.$key;
+
+			property_exists($this, $key) && $this->$key = $value;
+		}
+
+		isset($this->_expiration) OR $this->_expiration = (int) config_item('sess_expiration');
+		isset($this->_cookie_name) OR $this->_cookie_name = config_item('sess_cookie_name');
+		isset($this->_cookie_domain) OR $this->_cookie_domain = config_item('cookie_domain');
+		isset($this->_cookie_path) OR $this->_cookie_path = config_item('cookie_path');
+		isset($this->_cookie_secure) OR $this->_cookie_secure = config_item('cookie_secure');
+		isset($this->_cookie_httponly) OR $this->_cookie_httponly = config_item('cookie_httponly');
+		isset($this->_match_ip) OR $this->_match_ip = config_item('sess_match_ip');
+
+		// Pass our configuration to php.ini, when appropriate
+		ini_set('session.name', $this->_cookie_name);
+		isset($this->_cookie_domain) && ini_set('session.cookie_domain', $this->_cookie_domain);
+		isset($this->_cookie_path) && ini_set('session.cookie_path', $this->_cookie_path);
+		isset($this->_cookie_secure) && ini_set('session.cookie_secure', $this->_cookie_secure);
+		isset($this->_cookie_httponly) && ini_set('session.cookie_httponly', $this->_cookie_httponly);
+
+		if ($this->_expiration)
+		{
+			ini_set('session.gc_maxlifetime', $this->_expiration);
+		}
+
+		// Security is king
+		ini_set('session.use_trans_id', 0);
+		ini_set('session.use_strict_mode', 1);
+		ini_set('session.use_cookies', 1);
+		ini_set('session.use_only_cookies', 1);
+		ini_set('session.hash_function', 1);
+		ini_set('session.hash_bits_per_character', 4);
+
+		// Work-around for PHP bug #66827 (https://bugs.php.net/bug.php?id=66827)
+		//
+		// The session ID sanitizer doesn't check for the value type and blindly does
+		// an implicit cast to string, which triggers an 'Array to string' E_NOTICE.
+		if (isset($_COOKIE[$this->_cookie_name]) && ! is_string($_COOKIE[$this->_cookie_name]))
+		{
+			unset($_COOKIE[$this->_cookie_name]);
+		}
+
+/*
+		Need to test if this is necessary for a custom driver or if it's only
+		relevant to PHP's own files handler.
+
+		https://bugs.php.net/bug.php?id=65475
+		do this after session is started:
+		if (is_php('5.5.2') && ! is_php('5.5.4'))
+		{
+			$session_id = session_id();
+			if ($_COOKIE[$this->_cookie_name] !== $session_id && file_exists(teh file))
+			{
+				unlink(<teh file>);
+			}
+
+			setcookie(
+				$this->_cookie_name,
+				$session_id,
+				$this->_expiration
+					? time() + $this->_expiration
+					: 0,
+				$this->_cookie_path,
+				$this->_cookie_domain,
+				$this->_cookie_secure,
+				$this->_cookie_httponly
+			);
+		}
+*/
+	}
+
+	// ------------------------------------------------------------------------
+
+	protected function _cookie_destroy()
+	{
+		return setcookie(
+			$this->_cookie_name,
+			NULL,
+			1,
+			$this->_cookie_path,
+			$this->_cookie_domain,
+			$this->_cookie_secure,
+			$this->_cookie_httponly
+		);
+	}
+
+}
+
+/* End of file Session_driver.php */
+/* Location: ./system/libraries/Session/Session_driver.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_cookie.php b/system/libraries/Session/drivers/Session_cookie.php
deleted file mode 100644
index 566c40bd8..000000000
--- a/system/libraries/Session/drivers/Session_cookie.php
+++ /dev/null
@@ -1,805 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP 5.2.4 or newer
- *
- * NOTICE OF LICENSE
- *
- * Licensed under the Open Software License version 3.0
- *
- * This source file is subject to the Open Software License (OSL 3.0) that is
- * bundled with this package in the files license.txt / license.rst.  It is
- * also available through the world wide web at this URL:
- * http://opensource.org/licenses/OSL-3.0
- * If you did not receive a copy of the license and are unable to obtain it
- * through the world wide web, please send an email to
- * licensing@ellislab.com so we can send you a copy immediately.
- *
- * @package		CodeIgniter
- * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
- * @link		http://codeigniter.com
- * @since		Version 1.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * Cookie-based session management driver
- *
- * This is the classic CI_Session functionality, as written by EllisLab, abstracted out to a driver.
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/sessions.html
- */
-class CI_Session_cookie extends CI_Session_driver {
-
-	/**
-	 * Whether to encrypt the session cookie
-	 *
-	 * @var bool
-	 */
-	public $sess_encrypt_cookie		= FALSE;
-
-	/**
-	 * Whether to use to the database for session storage
-	 *
-	 * @var bool
-	 */
-	public $sess_use_database		= FALSE;
-
-	/**
-	 * Name of the database table in which to store sessions
-	 *
-	 * @var string
-	 */
-	public $sess_table_name			= '';
-
-	/**
-	 * Length of time (in seconds) for sessions to expire
-	 *
-	 * @var int
-	 */
-	public $sess_expiration			= 7200;
-
-	/**
-	 * Whether to kill session on close of browser window
-	 *
-	 * @var bool
-	 */
-	public $sess_expire_on_close	= FALSE;
-
-	/**
-	 * Whether to match session on ip address
-	 *
-	 * @var bool
-	 */
-	public $sess_match_ip			= FALSE;
-
-	/**
-	 * Whether to match session on user-agent
-	 *
-	 * @var bool
-	 */
-	public $sess_match_useragent	= TRUE;
-
-	/**
-	 * Name of session cookie
-	 *
-	 * @var string
-	 */
-	public $sess_cookie_name		= 'ci_session';
-
-	/**
-	 * Session cookie prefix
-	 *
-	 * @var string
-	 */
-	public $cookie_prefix			= '';
-
-	/**
-	 * Session cookie path
-	 *
-	 * @var string
-	 */
-	public $cookie_path				= '';
-
-	/**
-	 * Session cookie domain
-	 *
-	 * @var string
-	 */
-	public $cookie_domain			= '';
-
-	/**
-	 * Whether to set the cookie only on HTTPS connections
-	 *
-	 * @var bool
-	 */
-	public $cookie_secure			= FALSE;
-
-	/**
-	 * Whether cookie should be allowed only to be sent by the server
-	 *
-	 * @var bool
-	 */
-	public $cookie_httponly 		= FALSE;
-
-	/**
-	 * Interval at which to update session
-	 *
-	 * @var int
-	 */
-	public $sess_time_to_update		= 300;
-
-	/**
-	 * Key with which to encrypt the session cookie
-	 *
-	 * @var string
-	 */
-	public $encryption_key			= '';
-
-	/**
-	 * Timezone to use for the current time
-	 *
-	 * @var string
-	 */
-	public $time_reference			= 'local';
-
-	/**
-	 * Session data
-	 *
-	 * @var array
-	 */
-	public $userdata				= array();
-
-	/**
-	 * Current time
-	 *
-	 * @var int
-	 */
-	public $now;
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Default userdata keys
-	 *
-	 * @var	array
-	 */
-	protected $defaults = array(
-		'session_id' => NULL,
-		'ip_address' => NULL,
-		'user_agent' => NULL,
-		'last_activity' => NULL
-	);
-
-	/**
-	 * Data needs DB update flag
-	 *
-	 * @var	bool
-	 */
-	protected $data_dirty = FALSE;
-
-	/**
-	 * Standardize newlines flag
-	 *
-	 * @var	bool
-	 */
-	protected $_standardize_newlines;
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Initialize session driver object
-	 *
-	 * @return	void
-	 */
-	protected function initialize()
-	{
-		// Set all the session preferences, which can either be set
-		// manually via the $params array or via the config file
-		$prefs = array(
-			'sess_encrypt_cookie',
-			'sess_use_database',
-			'sess_table_name',
-			'sess_expiration',
-			'sess_expire_on_close',
-			'sess_match_ip',
-			'sess_match_useragent',
-			'sess_cookie_name',
-			'cookie_path',
-			'cookie_domain',
-			'cookie_secure',
-			'cookie_httponly',
-			'sess_time_to_update',
-			'time_reference',
-			'cookie_prefix',
-			'encryption_key',
-		);
-
-		$this->_standardize_newlines = (bool) config_item('standardize_newlines');
-
-		foreach ($prefs as $key)
-		{
-			$this->$key = isset($this->_parent->params[$key])
-				? $this->_parent->params[$key]
-				: $this->CI->config->item($key);
-		}
-
-		if (empty($this->encryption_key))
-		{
-			show_error('In order to use the Cookie Session driver you are required to set an encryption key in your config file.');
-		}
-
-		// Do we need encryption? If so, load the encryption class
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$this->CI->load->library('encryption');
-		}
-
-		// Check for database
-		if ($this->sess_use_database === TRUE && $this->sess_table_name !== '')
-		{
-			// Load database driver
-			$this->CI->load->database();
-
-			// Register shutdown function
-			register_shutdown_function(array($this, '_update_db'));
-		}
-
-		// Set the "now" time. Can either be GMT or server time, based on the config prefs.
-		// We use this to set the "last activity" time
-		$this->now = $this->_get_time();
-
-		// Set the session length. If the session expiration is
-		// set to zero we'll set the expiration two years from now.
-		if ($this->sess_expiration === 0)
-		{
-			$this->sess_expiration = (60*60*24*365*2);
-		}
-
-		// Set the cookie name
-		$this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;
-
-		// Run the Session routine. If a session doesn't exist we'll
-		// create a new one. If it does, we'll update it.
-		if ( ! $this->_sess_read())
-		{
-			$this->_sess_create();
-		}
-		else
-		{
-			$this->_sess_update();
-		}
-
-		// Delete expired sessions if necessary
-		$this->_sess_gc();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Write the session data
-	 *
-	 * @return	void
-	 */
-	public function sess_save()
-	{
-		// Check for database
-		if ($this->sess_use_database === TRUE)
-		{
-			// Mark custom data as dirty so we know to update the DB
-			$this->data_dirty = TRUE;
-		}
-
-		// Write the cookie
-		$this->_set_cookie();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Destroy the current session
-	 *
-	 * @return	void
-	 */
-	public function sess_destroy()
-	{
-		// Kill the session DB row
-		if ($this->sess_use_database === TRUE && isset($this->userdata['session_id']))
-		{
-			$this->CI->db->delete($this->sess_table_name, array('session_id' => $this->userdata['session_id']));
-			$this->data_dirty = FALSE;
-		}
-
-		// Kill the cookie
-		$this->_setcookie($this->sess_cookie_name, '', ($this->now - 31500000),
-			$this->cookie_path, $this->cookie_domain, 0);
-
-		// Kill session data
-		$this->userdata = array();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Regenerate the current session
-	 *
-	 * Regenerate the session id
-	 *
-	 * @param	bool	Destroy session data flag (default: false)
-	 * @return	void
-	 */
-	public function sess_regenerate($destroy = FALSE)
-	{
-		// Check destroy flag
-		if ($destroy)
-		{
-			// Destroy old session and create new one
-			$this->sess_destroy();
-			$this->_sess_create();
-		}
-		else
-		{
-			// Just force an update to recreate the id
-			$this->_sess_update(TRUE);
-		}
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Get a reference to user data array
-	 *
-	 * @return	array	Reference to userdata
-	 */
-	public function &get_userdata()
-	{
-		return $this->userdata;
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Fetch the current session data if it exists
-	 *
-	 * @return	bool
-	 */
-	protected function _sess_read()
-	{
-		// Fetch the cookie
-		$session = $this->CI->input->cookie($this->sess_cookie_name);
-
-		// No cookie? Goodbye cruel world!...
-		if ($session === NULL)
-		{
-			log_message('debug', 'A session cookie was not found.');
-			return FALSE;
-		}
-
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$session = $this->CI->encryption->decrypt($session);
-			if ($session === FALSE)
-			{
-				log_message('error', 'Session: Unable to decrypt the session cookie, possibly due to a HMAC mismatch.');
-				return FALSE;
-			}
-		}
-		else
-		{
-			if (($len = strlen($session) - 40) <= 0)
-			{
-				log_message('error', 'Session: The session cookie was not signed.');
-				return FALSE;
-			}
-
-			// Check cookie authentication
-			$hmac = substr($session, $len);
-			$session = substr($session, 0, $len);
-
-			// Time-attack-safe comparison
-			$hmac_check = hash_hmac('sha1', $session, $this->encryption_key);
-			$diff = 0;
-			for ($i = 0; $i < 40; $i++)
-			{
-				$diff |= ord($hmac[$i]) ^ ord($hmac_check[$i]);
-			}
-
-			if ($diff !== 0)
-			{
-				log_message('error', 'Session: HMAC mismatch. The session cookie data did not match what was expected.');
-				$this->sess_destroy();
-				return FALSE;
-			}
-		}
-
-		// Unserialize the session array
-		$session = @unserialize($session);
-
-		// Is the session data we unserialized an array with the correct format?
-		if ( ! is_array($session) OR ! isset($session['session_id'], $session['ip_address'], $session['user_agent'], $session['last_activity']))
-		{
-			log_message('debug', 'Session: Wrong cookie data format');
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Is the session current?
-		if (($session['last_activity'] + $this->sess_expiration) < $this->now OR $session['last_activity'] > $this->now)
-		{
-			log_message('debug', 'Session: Expired');
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Does the IP match?
-		if ($this->sess_match_ip === TRUE && $session['ip_address'] !== $this->CI->input->ip_address())
-		{
-			log_message('debug', 'Session: IP address mismatch');
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Does the User Agent Match?
-		if ($this->sess_match_useragent === TRUE &&
-			trim($session['user_agent']) !== trim(substr($this->CI->input->user_agent(), 0, 120)))
-		{
-			log_message('debug', 'Session: User Agent string mismatch');
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Is there a corresponding session in the DB?
-		if ($this->sess_use_database === TRUE)
-		{
-			$this->CI->db->where('session_id', $session['session_id']);
-
-			if ($this->sess_match_ip === TRUE)
-			{
-				$this->CI->db->where('ip_address', $session['ip_address']);
-			}
-
-			if ($this->sess_match_useragent === TRUE)
-			{
-				$this->CI->db->where('user_agent', $session['user_agent']);
-			}
-
-			// Is caching in effect? Turn it off
-			$db_cache = $this->CI->db->cache_on;
-			$this->CI->db->cache_off();
-
-			$query = $this->CI->db->limit(1)->get($this->sess_table_name);
-
-			// Was caching in effect?
-			if ($db_cache)
-			{
-				// Turn it back on
-				$this->CI->db->cache_on();
-			}
-
-			// No result? Kill it!
-			if (empty($query) OR $query->num_rows() === 0)
-			{
-				log_message('debug', 'Session: No match found in our database');
-				$this->sess_destroy();
-				return FALSE;
-			}
-
-			// Is there custom data? If so, add it to the main session array
-			$row = $query->row();
-			if ( ! empty($row->user_data))
-			{
-				$custom_data = unserialize(trim($row->user_data));
-
-				if (is_array($custom_data))
-				{
-					$session = $session + $custom_data;
-				}
-			}
-		}
-
-		// Session is valid!
-		$this->userdata = $session;
-		return TRUE;
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Create a new session
-	 *
-	 * @return	void
-	 */
-	protected function _sess_create()
-	{
-		// Initialize userdata
-		$this->userdata = array(
-			'session_id'	=> $this->_make_sess_id(),
-			'ip_address'	=> $this->CI->input->ip_address(),
-			'user_agent'	=> trim(substr($this->CI->input->user_agent(), 0, 120)),
-			'last_activity'	=> $this->now,
-		);
-
-		log_message('debug', 'Session: Creating new session ('.$this->userdata['session_id'].')');
-
-		// Check for database
-		if ($this->sess_use_database === TRUE)
-		{
-			// Add empty user_data field and save the data to the DB
-			$this->CI->db->set('user_data', '')->insert($this->sess_table_name, $this->userdata);
-		}
-
-		// Write the cookie
-		$this->_set_cookie();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Update an existing session
-	 *
-	 * @param	bool	Force update flag (default: false)
-	 * @return	void
-	 */
-	protected function _sess_update($force = FALSE)
-	{
-		// We only update the session every five minutes by default (unless forced)
-		if ( ! $force && ($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
-		{
-			return;
-		}
-
-		// Update last activity to now
-		$this->userdata['last_activity'] = $this->now;
-
-		// Save the old session id so we know which DB record to update
-		$old_sessid = $this->userdata['session_id'];
-
-		// Changing the session ID during an AJAX call causes problems
-		if ( ! $this->CI->input->is_ajax_request())
-		{
-			// Get new id
-			$this->userdata['session_id'] = $this->_make_sess_id();
-
-			log_message('debug', 'Session: Regenerate ID');
-		}
-
-		// Check for database
-		if ($this->sess_use_database === TRUE)
-		{
-			$this->CI->db->where('session_id', $old_sessid);
-
-			if ($this->sess_match_ip === TRUE)
-			{
-				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
-			}
-
-			if ($this->sess_match_useragent === TRUE)
-			{
-				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
-			}
-
-			// Update the session ID and last_activity field in the DB
-			$this->CI->db->update($this->sess_table_name,
-				array(
-					'last_activity' => $this->now,
-					'session_id' => $this->userdata['session_id']
-				)
-			);
-		}
-
-		// Write the cookie
-		$this->_set_cookie();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Update database with current data
-	 *
-	 * This gets called from the shutdown function and also
-	 * registered with PHP to run at the end of the request
-	 * so it's guaranteed to update even when a fatal error
-	 * occurs. The first call makes the update and clears the
-	 * dirty flag so it won't happen twice.
-	 *
-	 * @return	void
-	 */
-	public function _update_db()
-	{
-		// Check for database and dirty flag and unsaved
-		if ($this->sess_use_database === TRUE && $this->data_dirty === TRUE)
-		{
-			// Set up activity and data fields to be set
-			// If we don't find custom data, user_data will remain an empty string
-			$set = array(
-				'last_activity' => $this->userdata['last_activity'],
-				'user_data' => ''
-			);
-
-			// Get the custom userdata, leaving out the defaults
-			// (which get stored in the cookie)
-			$userdata = array_diff_key($this->userdata, $this->defaults);
-
-			// Did we find any custom data?
-			if ( ! empty($userdata))
-			{
-				// Serialize the custom data array so we can store it
-				$set['user_data'] = serialize($userdata);
-			}
-
-			// Reset query builder values.
-			$this->CI->db->reset_query();
-
-			// Run the update query
-			// Any time we change the session id, it gets updated immediately,
-			// so our where clause below is always safe
-			$this->CI->db->where('session_id', $this->userdata['session_id']);
-
-			if ($this->sess_match_ip === TRUE)
-			{
-				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
-			}
-
-			if ($this->sess_match_useragent === TRUE)
-			{
-				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
-			}
-
-			$this->CI->db->update($this->sess_table_name, $set);
-
-			// Clear dirty flag to prevent double updates
-			$this->data_dirty = FALSE;
-
-			log_message('debug', 'CI_Session Data Saved To DB');
-		}
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Generate a new session id
-	 *
-	 * @return	string	Hashed session id
-	 */
-	protected function _make_sess_id()
-	{
-		$new_sessid = '';
-		do
-		{
-			$new_sessid .= mt_rand();
-		}
-		while (strlen($new_sessid) < 32);
-
-		// To make the session ID even more secure we'll combine it with the user's IP
-		$new_sessid .= $this->CI->input->ip_address();
-
-		// Turn it into a hash and return
-		return md5(uniqid($new_sessid, TRUE));
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Get the "now" time
-	 *
-	 * @return	int	 Time
-	 */
-	protected function _get_time()
-	{
-		if ($this->time_reference === 'local' OR $this->time_reference === date_default_timezone_get())
-		{
-			return time();
-		}
-
-		$datetime = new DateTime('now', new DateTimeZone($this->time_reference));
-		sscanf($datetime->format('j-n-Y G:i:s'), '%d-%d-%d %d:%d:%d', $day, $month, $year, $hour, $minute, $second);
-
-		return mktime($hour, $minute, $second, $month, $day, $year);
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Write the session cookie
-	 *
-	 * @return	void
-	 */
-	protected function _set_cookie()
-	{
-		// Get userdata (only defaults if database)
-		$cookie_data = ($this->sess_use_database === TRUE)
-				? array_intersect_key($this->userdata, $this->defaults)
-				: $this->userdata;
-
-		// The Input class will do this and since we use HMAC verification,
-		// unless we standardize here as well, the hash won't match.
-		if ($this->_standardize_newlines)
-		{
-			foreach (array_keys($this->userdata) as $key)
-			{
-				$this->userdata[$key] = preg_replace('/(?:\r\n|[\r\n])/', PHP_EOL, $this->userdata[$key]);
-			}
-		}
-
-		// Serialize the userdata for the cookie
-		$cookie_data = serialize($cookie_data);
-
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$cookie_data = $this->CI->encryption->encrypt($cookie_data);
-		}
-		else
-		{
-			// Require message authentication
-			$cookie_data .= hash_hmac('sha1', $cookie_data, $this->encryption_key);
-		}
-
-		$expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();
-
-		// Set the cookie
-		$this->_setcookie($this->sess_cookie_name, $cookie_data, $expire, $this->cookie_path, $this->cookie_domain,
-			$this->cookie_secure, $this->cookie_httponly);
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Set a cookie with the system
-	 *
-	 * This abstraction of the setcookie call allows overriding for unit testing
-	 *
-	 * @param	string	Cookie name
-	 * @param	string	Cookie value
-	 * @param	int	Expiration time
-	 * @param	string	Cookie path
-	 * @param	string	Cookie domain
-	 * @param	bool	Secure connection flag
-	 * @param	bool	HTTP protocol only flag
-	 * @return	void
-	 */
-	protected function _setcookie($name, $value = '', $expire = 0, $path = '', $domain = '', $secure = FALSE, $httponly = FALSE)
-	{
-		setcookie($name, $value, $expire, $path, $domain, $secure, $httponly);
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Garbage collection
-	 *
-	 * This deletes expired session rows from database
-	 * if the probability percentage is met
-	 *
-	 * @return	void
-	 */
-	protected function _sess_gc()
-	{
-		if ($this->sess_use_database !== TRUE)
-		{
-			return;
-		}
-
-		$probability = ini_get('session.gc_probability');
-		$divisor = ini_get('session.gc_divisor');
-
-		if (mt_rand(1, $divisor) <= $probability)
-		{
-			$expire = $this->now - $this->sess_expiration;
-			$this->CI->db->delete($this->sess_table_name, 'last_activity < '.$expire);
-
-			log_message('debug', 'Session garbage collection performed.');
-		}
-	}
-
-}
-
-/* End of file Session_cookie.php */
-/* Location: ./system/libraries/Session/drivers/Session_cookie.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_database_driver.php b/system/libraries/Session/drivers/Session_database_driver.php
new file mode 100644
index 000000000..24847456c
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_database_driver.php
@@ -0,0 +1,317 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		Andrey Andreev
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * CodeIgniter Session Database Driver
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session_database_driver extends CI_Session_driver implements SessionHandlerInterface {
+
+	/**
+	 * DB object
+	 *
+	 * @var	object
+	 */
+	protected $_db;
+
+	/**
+	 * DB table
+	 *
+	 * @var	string
+	 */
+	protected $_table;
+
+	/**
+	 * Session ID
+	 *
+	 * @var	string
+	 */
+	protected $_session_id;
+
+	/**
+	 * Row exists flag
+	 *
+	 * @var	bool
+	 */
+	protected $_row_exists = FALSE;
+
+	/**
+	 * Lock "driver" flag
+	 *
+	 * @var	string
+	 */
+	protected $_lock_driver;
+
+	/**
+	 * Lock status flag
+	 *
+	 * @var	bool
+	 */
+	protected $_lock = FALSE;
+
+	/**
+	 * Semaphore ID
+	 *
+	 * Used for locking if the database doesn't support advisory locks
+	 *
+	 * @var	resource
+	 */
+	protected $_sem;
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params	Configuration parameters
+	 * @return	void
+	 */
+	public function __construct(&$params)
+	{
+		parent::__construct($params);
+
+		$CI =& get_instance();
+		isset($CI->db) OR $CI->load->database();
+		$this->_db =& $CI->db;
+
+		if ( ! $this->_db instanceof CI_DB_query_builder)
+		{
+			throw new Exception('Query Builder not enabled for the configured database. Aborting.');
+		}
+		elseif ($this->_db->pconnect)
+		{
+			throw new Exception('Configured database connection is persistent. Aborting.');
+		}
+
+		$db_driver = $this->_db->dbdriver.(empty($this->_db->subdriver) ? '' : '_'.$this->_db->subdriver);
+		if (strpos($db_driver, 'mysql') !== FALSE)
+		{
+			$this->_lock_type = 'mysql';
+		}
+		elseif (in_array($db_driver, array('postgre', 'pdo_pgsql'), TRUE))
+		{
+			$this->_lock_type = 'postgre';
+		}
+		elseif (extension_loaded('sysvsem'))
+		{
+			$this->_lock_type = 'semaphore';
+		}
+
+		isset($this->_table) OR $this->_table = config_item('sess_table_name');
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function open($save_path, $name)
+	{
+		return empty($this->_db->conn_id)
+			? ( ! $this->_db->autoinit && $this->_db->db_connect())
+			: TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function read($session_id)
+	{
+		$this->_session_id = $session_id;
+		if (($this->_lock = $this->_get_lock()) !== FALSE)
+		{
+			$this->_db
+				->select('data')
+				->from($this->_table)
+				->where('id', $session_id);
+
+			if ($this->_match_ip)
+			{
+				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
+			}
+
+			if (($result = $this->_db->get()->row()) === NULL)
+			{
+				$this->_fingerprint = md5('');
+				return '';
+			}
+
+			$this->_fingerprint = md5(rtrim($result->data));
+			$this->_row_exists = TRUE;
+			return $result->data;
+		}
+
+		$this->_fingerprint = md5('');
+		return '';
+	}
+
+	public function write($session_id, $session_data)
+	{
+		if ($this->_lock === FALSE)
+		{
+			return FALSE;
+		}
+
+		if ($this->_row_exists === FALSE)
+		{
+			if ($this->_db->insert($this->_table, array('id' => $session_id, 'ip_address' => $_SERVER['REMOTE_ADDR'], 'timestamp' => time(), 'data' => $session_data)))
+			{
+				$this->_fingerprint = md5($session_data);
+				return $this->_row_exists = TRUE;
+			}
+
+			return FALSE;
+		}
+
+		$this->_db->where('id', $session_id);
+		if ($this->_match_ip)
+		{
+			$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
+		}
+
+		$update_data = ($this->_fingerprint === md5($session_data))
+			? array('timestamp' => time())
+			: array('timestamp' => time(), 'data' => $session_data);
+
+		if ($this->_db->update($this->_table, $update_data))
+		{
+			$this->_fingerprint = md5($session_data);
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function close()
+	{
+		return ($this->_lock)
+			? $this->_release_lock()
+			: TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function destroy($session_id)
+	{
+		if ($this->_lock)
+		{
+			$this->_db->where('id', $session_id);
+			if ($this->_match_ip)
+			{
+				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
+			}
+
+			return $this->_db->delete($this->_table)
+				? ($this->close() && $this->_cookie_destroy())
+				: FALSE;
+		}
+
+		return ($this->close() && $this->_cookie_destroy());
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function gc($maxlifetime)
+	{
+		return $this->_db->delete($this->_table, 'timestamp < '.(time() - $maxlifetime));
+	}
+
+	// ------------------------------------------------------------------------
+
+	protected function _get_lock()
+	{
+		$arg = $this->_session_id
+			.($this->_match_ip ? '_'.$_SERVER['REMOTE_ADDR'] : '');
+
+		if ($this->_lock_driver === 'mysql')
+		{
+			return (bool) $this->_db
+				->query("SELECT GET_LOCK('".$session_id."', 10) AS ci_session_lock")
+				->row()
+				->ci_session_lock;
+		}
+		elseif ($this->_lock_driver === 'postgre')
+		{
+			return (bool) $this->_db->simple_query('SELECT pg_advisory_lock('.$arg.')');
+		}
+		elseif ($this->_lock_driver === 'semaphore')
+		{
+			if (($this->_sem = sem_get($arg, 1, 0644)) === FALSE)
+			{
+				return FALSE;
+			}
+
+			if ( ! sem_acquire($this->_sem))
+			{
+				sem_remove($this->_sem);
+				return FALSE;
+			}
+
+			return TRUE;
+		}
+
+		return TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	protected function _release_lock()
+	{
+		if ($this->_lock_driver === 'mysql')
+		{
+			$arg = $this->_session_id
+				.($this->_match_ip ? '_'.$_SERVER['REMOTE_ADDR'] : '');
+
+			return (bool) $this->_db
+				->query("SELECT RELEASE_LOCK('".$arg."') AS ci_session_lock")
+				->row()
+				->ci_session_lock;
+		}
+		elseif ($this->_lock_driver === 'postgre')
+		{
+			$arg = "hashtext('".$this->_session_id."')"
+				.($this->_match_ip ? ", hashtext('".$_SERVER['REMOTE_ADDR']."')" : '');
+
+			return (bool) $this->_db->simple_query('SELECT pg_advisory_unlock('.$arg.')');
+		}
+		elseif ($this->_lock_driver === 'semaphore')
+		{
+			sem_release($this->_sem);
+			sem_remove($this->_sem);
+		}
+
+		return TRUE;
+	}
+
+}
+
+/* End of file Session_database_driver.php */
+/* Location: ./system/libraries/Session/drivers/Session_database_driver.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_files_driver.php b/system/libraries/Session/drivers/Session_files_driver.php
new file mode 100644
index 000000000..4acbcf6c5
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_files_driver.php
@@ -0,0 +1,276 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		Andrey Andreev
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * CodeIgniter Session Files Driver
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session_files_driver extends CI_Session_driver implements SessionHandlerInterface {
+
+	/**
+	 * Save path
+	 *
+	 * @var	string
+	 */
+	protected $_save_path;
+
+	/**
+	 * File handle
+	 *
+	 * @var	resource
+	 */
+	protected $_file_handle;
+
+	/**
+	 * File name
+	 *
+	 * @var	resource
+	 */
+	protected $_file_path;
+
+	/**
+	 * File new flag
+	 *
+	 * @var	bool
+	 */
+	protected $_file_new;
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params	Configuration parameters
+	 * @return	void
+	 */
+	public function __construct(&$params)
+	{
+		parent::__construct($params);
+
+		if (isset($this->_save_path))
+		{
+			$this->_save_path = rtrim($this->_save_path, '/\\');
+			ini_set('session.save_path', $this->_save_path);
+		}
+		else
+		{
+			$this->_save_path = rtrim(ini_get('session.save_path'), '/\\');
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function open($save_path, $name)
+	{
+		if ( ! is_dir($save_path) && ! mkdir($save_path, 0700, TRUE))
+		{
+			log_message('error', "Session: Configured save path '".$this->_save_path."' is not a directory, doesn't exist or cannot be created.");
+			return FALSE;
+		}
+
+		$this->_save_path = $save_path;
+		$this->_file_path = $this->_save_path.DIRECTORY_SEPARATOR
+			.$name // we'll use the session cookie name as a prefix to avoid collisions
+			.($this->_match_ip ? md5($_SERVER['REMOTE_ADDR']) : '');
+
+		return TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function read($session_id)
+	{
+		// This might seem weird, but PHP 5.6 introduces session_reset(),
+		// which re-reads session data
+		if ($this->_file_handle === NULL)
+		{
+			$this->_file_path .= $session_id;
+
+			// Just using fopen() with 'c+b' mode would be perfect, but it is only
+			// available since PHP 5.2.6 and we have to set permissions for new files,
+			// so we'd have to hack around this ...
+			if (($this->_file_new = ! file_exists($this->_file_path)) === TRUE)
+			{
+				if (($this->_file_handle = fopen($this->_file_path, 'w+b')) === FALSE)
+				{
+					log_message('error', "Session: File '".$this->_file_path."' doesn't exist and cannot be created.");
+					return FALSE;
+				}
+			}
+			elseif (($this->_file_handle = fopen($this->_file_path, 'r+b')) === FALSE)
+			{
+				log_message('error', "Session: Unable to open file '".$this->_file_path."'.");
+				return FALSE;
+			}
+
+			if (flock($this->_file_handle, LOCK_EX) === FALSE)
+			{
+				log_message('error', "Session: Unable to obtain lock for file '".$this->_file_path."'.");
+				fclose($this->_file_handle);
+				$this->_file_handle = NULL;
+				return FALSE;
+			}
+
+			if ($this->_file_new)
+			{
+				chmod($this->_file_path, 0600);
+				$this->_fingerprint = md5('');
+				return '';
+			}
+		}
+		else
+		{
+			rewind($this->_file_handle);
+		}
+
+		$session_data = '';
+		for ($read = 0, $length = filesize($this->_file_path); $read < $length; $read += strlen($buffer))
+		{
+			if (($buffer = fread($this->_file_handle, $length - $read)) === FALSE)
+			{
+				break;
+			}
+
+			$session_data .= $buffer;
+		}
+
+		$this->_fingerprint = md5($session_data);
+		return $session_data;
+	}
+
+	public function write($session_id, $session_data)
+	{
+		if ( ! is_resource($this->_file_handle))
+		{
+			return FALSE;
+		}
+		elseif ($this->_fingerprint === md5($session_data))
+		{
+			return ($this->_file_new)
+				? TRUE
+				: touch($this->_file_path);
+		}
+
+		if ( ! $this->_file_new)
+		{
+			ftruncate($this->_file_handle, 0);
+			rewind($this->_file_handle);
+		}
+
+		for ($written = 0, $length = strlen($session_data); $written < $length; $written += $result)
+		{
+			if (($result = fwrite($this->_file_handle, substr($session_data, $written))) === FALSE)
+			{
+				break;
+			}
+		}
+
+		if ( ! is_int($result))
+		{
+			$this->_fingerprint = md5(substr($session_data, 0, $written));
+			log_message('error', 'Session: Unable to write data.');
+			return FALSE;
+		}
+
+		$this->_fingerprint = md5($session_data);
+		return TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function close()
+	{
+		if (is_resource($this->_file_handle))
+		{
+			flock($this->_file_handle, LOCK_UN);
+			fclose($this->_file_handle);
+
+			$this->_file_handle = $this->_file_new = NULL;
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function destroy($session_id)
+	{
+		if ($this->close())
+		{
+			return unlink($this->_file_path) && $this->_cookie_destroy();
+		}
+		elseif ($this->_file_path !== NULL)
+		{
+			clearstatcache();
+			return file_exists($this->_file_path)
+				? (unlink($this->_file_path) && $this->_cookie_destroy())
+				: TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	public function gc($maxlifetime)
+	{
+		if ( ! is_dir($this->_save_path) OR ($files = scandir($this->_save_path)) === FALSE)
+		{
+			log_message('debug', "Session: Garbage collector couldn't list files under directory '".$this->_save_path."'.");
+			return FALSE;
+		}
+
+		$ts = time() - $maxlifetime;
+
+		foreach ($files as $file)
+		{
+			// If the filename doesn't match this pattern, it's either not a session file or is not ours
+			if ( ! preg_match('/(?:[0-9a-f]{32})?[0-9a-f]{40}$/i', $file)
+				OR ! is_file($this->_save_path.DIRECTORY_SEPARATOR.$file)
+				OR ($mtime = filemtime($file)) === FALSE
+				OR $mtime > $ts)
+			{
+				continue;
+			}
+
+			unlink($this->_save_path.DIRECTORY_SEPARATOR.$file);
+		}
+
+		return TRUE;
+	}
+
+}
+
+/* End of file Session_files_driver.php */
+/* Location: ./system/libraries/Session/drivers/Session_files_driver.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_native.php b/system/libraries/Session/drivers/Session_native.php
deleted file mode 100644
index 4104652b8..000000000
--- a/system/libraries/Session/drivers/Session_native.php
+++ /dev/null
@@ -1,246 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP 5.2.4 or newer
- *
- * NOTICE OF LICENSE
- *
- * Licensed under the Open Software License version 3.0
- *
- * This source file is subject to the Open Software License (OSL 3.0) that is
- * bundled with this package in the files license.txt / license.rst.  It is
- * also available through the world wide web at this URL:
- * http://opensource.org/licenses/OSL-3.0
- * If you did not receive a copy of the license and are unable to obtain it
- * through the world wide web, please send an email to
- * licensing@ellislab.com so we can send you a copy immediately.
- *
- * @package		CodeIgniter
- * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
- * @link		http://codeigniter.com
- * @since		Version 1.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * Native PHP session management driver
- *
- * This is the driver that uses the native PHP $_SESSION array through the Session driver library.
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author		EllisLab Dev Team
- */
-class CI_Session_native extends CI_Session_driver {
-
-	/**
-	 * Initialize session driver object
-	 *
-	 * @return	void
-	 */
-	protected function initialize()
-	{
-		// Get config parameters
-		$config = array();
-		$prefs = array(
-			'sess_cookie_name',
-			'sess_expire_on_close',
-			'sess_expiration',
-			'sess_match_ip',
-			'sess_match_useragent',
-			'sess_time_to_update',
-			'cookie_prefix',
-			'cookie_path',
-			'cookie_domain',
-			'cookie_secure',
-			'cookie_httponly'
-		);
-
-		foreach ($prefs as $key)
-		{
-			$config[$key] = isset($this->_parent->params[$key])
-				? $this->_parent->params[$key]
-				: $this->CI->config->item($key);
-		}
-
-		// Set session name, if specified
-		if ($config['sess_cookie_name'])
-		{
-			// Differentiate name from cookie driver with '_id' suffix
-			$name = $config['sess_cookie_name'].'_id';
-			if ($config['cookie_prefix'])
-			{
-				// Prepend cookie prefix
-				$name = $config['cookie_prefix'].$name;
-			}
-			session_name($name);
-		}
-
-		// Set expiration, path, and domain
-		$expire = 7200;
-		$path = '/';
-		$domain = '';
-		$secure = (bool) $config['cookie_secure'];
-		$http_only = (bool) $config['cookie_httponly'];
-
-		if ($config['sess_expiration'] !== FALSE)
-		{
-			// Default to 2 years if expiration is "0"
-			$expire = ($config['sess_expiration'] == 0) ? (60*60*24*365*2) : $config['sess_expiration'];
-		}
-
-		if ($config['cookie_path'])
-		{
-			// Use specified path
-			$path = $config['cookie_path'];
-		}
-
-		if ($config['cookie_domain'])
-		{
-			// Use specified domain
-			$domain = $config['cookie_domain'];
-		}
-
-		session_set_cookie_params($config['sess_expire_on_close'] ? 0 : $expire, $path, $domain, $secure, $http_only);
-
-		// Start session
-		session_start();
-
-		// Check session expiration, ip, and agent
-		$now = time();
-		$destroy = FALSE;
-		if (isset($_SESSION['last_activity']) && (($_SESSION['last_activity'] + $expire) < $now OR $_SESSION['last_activity'] > $now))
-		{
-			// Expired - destroy
-			log_message('debug', 'Session: Expired');
-			$destroy = TRUE;
-		}
-		elseif ($config['sess_match_ip'] === TRUE && isset($_SESSION['ip_address'])
-			&& $_SESSION['ip_address'] !== $this->CI->input->ip_address())
-		{
-			// IP doesn't match - destroy
-			log_message('debug', 'Session: IP address mismatch');
-			$destroy = TRUE;
-		}
-		elseif ($config['sess_match_useragent'] === TRUE && isset($_SESSION['user_agent'])
-			&& $_SESSION['user_agent'] !== trim(substr($this->CI->input->user_agent(), 0, 50)))
-		{
-			// Agent doesn't match - destroy
-			log_message('debug', 'Session: User Agent string mismatch');
-			$destroy = TRUE;
-		}
-
-		// Destroy expired or invalid session
-		if ($destroy)
-		{
-			// Clear old session and start new
-			$this->sess_destroy();
-			session_start();
-		}
-
-		// Check for update time
-		if ($config['sess_time_to_update'] && isset($_SESSION['last_activity'])
-			&& ($_SESSION['last_activity'] + $config['sess_time_to_update']) < $now)
-		{
-			// Changing the session ID amidst a series of AJAX calls causes problems
-			if ( ! $this->CI->input->is_ajax_request())
-			{
-				// Regenerate ID, but don't destroy session
-				log_message('debug', 'Session: Regenerate ID');
-				$this->sess_regenerate(FALSE);
-			}
-		}
-
-		// Set activity time
-		$_SESSION['last_activity'] = $now;
-
-		// Set matching values as required
-		if ($config['sess_match_ip'] === TRUE && ! isset($_SESSION['ip_address']))
-		{
-			// Store user IP address
-			$_SESSION['ip_address'] = $this->CI->input->ip_address();
-		}
-
-		if ($config['sess_match_useragent'] === TRUE && ! isset($_SESSION['user_agent']))
-		{
-			// Store user agent string
-			$_SESSION['user_agent'] = trim(substr($this->CI->input->user_agent(), 0, 50));
-		}
-
-		// Make session ID available
-		$_SESSION['session_id'] = session_id();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Save the session data
-	 *
-	 * @return	void
-	 */
-	public function sess_save()
-	{
-		// Nothing to do - changes to $_SESSION are automatically saved
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Destroy the current session
-	 *
-	 * @return	void
-	 */
-	public function sess_destroy()
-	{
-		// Cleanup session
-		$_SESSION = array();
-		$name = session_name();
-		if (isset($_COOKIE[$name]))
-		{
-			// Clear session cookie
-			$params = session_get_cookie_params();
-			setcookie($name, '', time() - 42000, $params['path'], $params['domain'], $params['secure'], $params['httponly']);
-			unset($_COOKIE[$name]);
-		}
-		session_destroy();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Regenerate the current session
-	 *
-	 * Regenerate the session id
-	 *
-	 * @param	bool	Destroy session data flag (default: FALSE)
-	 * @return	void
-	 */
-	public function sess_regenerate($destroy = FALSE)
-	{
-		// Just regenerate id, passing destroy flag
-		session_regenerate_id($destroy);
-		$_SESSION['session_id'] = session_id();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Get a reference to user data array
-	 *
-	 * @return	array	Reference to userdata
-	 */
-	public function &get_userdata()
-	{
-		// Just return reference to $_SESSION
-		return $_SESSION;
-	}
-
-}
-
-/* End of file Session_native.php */
-/* Location: ./system/libraries/Session/drivers/Session_native.php */
\ No newline at end of file