system/libraries/Session/Session.php - code-igniter-v3-giggi - Gitiles

 <?php
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.2.4 or newer
  *
  * This content is released under the MIT License (MIT)
  *
  * Copyright (c) 2014, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
  * @copyright	Copyright (c) 2014, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	http://codeigniter.com
  * @since	Version 2.0.0
  * @filesource
  */
 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
  * @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');

 	/**
 	 * 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;

 	// ------------------------------------------------------------------------

 	/**
 	 * 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.
 	 *
 	 * @param	array	Configuration parameters
 	 * @return	void
 	 */
 	public function __construct(array $params = array())
 	{
 		$_config =& get_instance()->config;

 		// No sessions under CLI
 		if (is_cli())
 		{
 			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))
 		{
 			$drivers = array_map('strtolower', (array) $drivers);
 			$this->valid_drivers = array_merge($this->valid_drivers, array_diff($drivers, $this->valid_drivers));
 		}

 		// Get driver to load
 		$driver = isset($params['sess_driver']) ? $params['sess_driver'] : $_config->item('sess_driver');
 		if ( ! $driver)
 		{
 			log_message('debug', "Session: No driver name is configured, defaulting to 'cookie'.");
 			$driver = 'cookie';
 		}

 		if ( ! in_array($driver, $this->valid_drivers))
 		{
 			log_message('error', 'Session: Configured driver name is not valid, aborting.');
 			return;
 		}

 		// Save a copy of parameters in case drivers need access
 		$this->params = $params;

 		// Load driver and get array reference
 		$this->load_driver($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();

 		// Delete expired tempdata
 		$this->_tempdata_sweep();

 		log_message('debug', 'CI_Session routines successfully run');
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * 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;
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * 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', $this->valid_drivers)))
 		{
 			// See if driver is loaded
 			if (isset($this->$child))
 			{
 				// See if driver is already current
 				if ($this->$child !== $this->current)
 				{
 					// Make driver current and sync userdata
 					$this->current = $this->$child;
 					$this->userdata =& $this->current->get_userdata();
 				}
 			}
 			else
 			{
 				// Load new driver
 				$this->load_driver($child);
 			}
 		}
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Destroy the current session
 	 *
 	 * @return	void
 	 */
 	public function sess_destroy()
 	{
 		// Just call destroy on driver
 		$this->current->sess_destroy();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * 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();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Fetch a specific item from the session array
 	 *
 	 * @param	string	Item key
 	 * @return	string	Item value or NULL if not found
 	 */
 	public function userdata($item = NULL)
 	{
 		if (isset($item))
 		{
 			return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
 		}

 		return isset($this->userdata) ? $this->userdata : array();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * 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();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Add or change data in the "userdata" array
 	 *
 	 * @param	mixed	Item name or array of items
 	 * @param	string	Item value or empty string
 	 * @return	void
 	 */
 	public function set_userdata($newdata, $newval = '')
 	{
 		// Wrap params as array if singular
 		if (is_string($newdata))
 		{
 			$newdata = array($newdata => $newval);
 		}

 		// Set each name/value pair
 		if (count($newdata) > 0)
 		{
 			foreach ($newdata as $key => $val)
 			{
 				$this->userdata[$key] = $val;
 			}
 		}

 		// Tell driver data changed
 		$this->current->sess_save();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Delete a session variable from the "userdata" array
 	 *
 	 * @param	mixed	Item name or array of item names
 	 * @return	void
 	 */
 	public function unset_userdata($newdata)
 	{
 		// Wrap single name as array
 		if (is_string($newdata))
 		{
 			$newdata = array($newdata => '');
 		}

 		// Unset each item name
 		if (count($newdata) > 0)
 		{
 			foreach (array_keys($newdata) as $key)
 			{
 				unset($this->userdata[$key]);
 			}
 		}

 		// Tell driver data changed
 		$this->current->sess_save();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Determine if an item exists
 	 *
 	 * @param	string	Item name
 	 * @return	bool
 	 */
 	public function has_userdata($item)
 	{
 		return isset($this->userdata[$item]);
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Add or change flashdata, only available until the next request
 	 *
 	 * @param	mixed	Item name or array of items
 	 * @param	string	Item value or empty string
 	 * @return	void
 	 */
 	public function set_flashdata($newdata, $newval = '')
 	{
 		// Wrap item as array if singular
 		if (is_string($newdata))
 		{
 			$newdata = array($newdata => $newval);
 		}

 		// Prepend each key name and set value
 		if (count($newdata) > 0)
 		{
 			foreach ($newdata as $key => $val)
 			{
 				$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
 				$this->set_userdata($flashdata_key, $val);
 			}
 		}
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Keeps existing flashdata available to next request.
 	 *
 	 * @param	mixed	Item key(s)
 	 * @return	void
 	 */
 	public function keep_flashdata($key)
 	{

 		if (is_array($key))
 		{
 			foreach ($key as $k)
 			{
 				$this->keep_flashdata($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);
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Fetch a specific flashdata item from the session array
 	 *
 	 * @param	string	Item key
 	 * @return	string
 	 */
 	public function flashdata($key = NULL)
 	{
 		if (isset($key))
 		{
 			return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key);
 		}

 		// Get our flashdata items from userdata
 		$out = array();
 		foreach ($this->userdata() as $key => $val)
 		{
 			if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_OLD) !== FALSE)
 			{
 				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_OLD, '', $key);
 				$out[$key] = $val;
 			}
 		}

 		return $out;
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Add or change tempdata, only available until expiration
 	 *
 	 * @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
 	 * @return	void
 	 */
 	public function set_tempdata($newdata, $newval = '', $expire = 0)
 	{
 		// 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();
 		}

 		// 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);
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Delete a temporary session variable from the "userdata" array
 	 *
 	 * @param	mixed	Item name or array of item names
 	 * @return	void
 	 */
 	public function unset_tempdata($newdata)
 	{
 		// 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 => '');
 		}

 		// 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);
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Fetch a specific tempdata item from the session array
 	 *
 	 * @param	string	Item key
 	 * @return	string
 	 */
 	public function tempdata($key = NULL)
 	{
 		if (isset($key))
 		{
 			return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key);
 		}

 		// Get our tempdata items from userdata
 		$out = array();
 		foreach ($this->userdata() as $key => $val)
 		{
 			if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_EXP) !== FALSE)
 			{
 				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_EXP, '', $key);
 				$out[$key] = $val;
 			}
 		}

 		return $out;
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Identifies flashdata as 'old' for removal
 	 * when _flashdata_sweep() runs.
 	 *
 	 * @return	void
 	 */
 	protected function _flashdata_mark()
 	{
 		foreach ($this->userdata() as $name => $value)
 		{
 			$parts = explode(self::FLASHDATA_NEW, $name);
 			if (count($parts) === 2)
 			{
 				$this->set_userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1], $value);
 				$this->unset_userdata($name);
 			}
 		}
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Removes all flashdata marked as 'old'
 	 *
 	 * @return	void
 	 */
 	protected function _flashdata_sweep()
 	{
 		$userdata = $this->userdata();
 		foreach (array_keys($userdata) as $key)
 		{
 			if (strpos($key, self::FLASHDATA_OLD))
 			{
 				$this->unset_userdata($key);
 			}
 		}
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Removes all expired tempdata
 	 *
 	 * @return	void
 	 */
 	protected function _tempdata_sweep()
 	{
 		// 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 $key)
 		{
 			if (strpos($key, self::FLASHDATA_EXP) && $expirations[$key] < $now)
 			{
 				unset($expirations[$key]);
 				$this->unset_userdata($key);
 			}
 		}

 		// Update expiration list
 		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
 	}

 }

 // ------------------------------------------------------------------------

 /**
  * 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
 	 *
 	 * Gets the CI singleton, so that individual drivers
 	 * don't have to do it separately.
 	 *
 	 * @return	void
 	 */
 	public function __construct()
 	{
 		$this->CI =& get_instance();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Decorate
 	 *
 	 * Decorates the child with the parent driver lib's methods and properties
 	 *
 	 * @param	object	Parent library object
 	 * @return	void
 	 */
 	public function decorate($parent)
 	{
 		// Call base class decorate first
 		parent::decorate($parent);

 		// Call initialize method now that driver has access to $this->_parent
 		$this->initialize();
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * __call magic method
 	 *
 	 * Handles access to the parent driver library's methods
 	 *
 	 * @param	string	Library method name
 	 * @param	array	Method arguments (default: none)
 	 * @return	mixed
 	 */
 	public function __call($method, $args = array())
 	{
 		// Make sure the parent library uses this driver
 		$this->_parent->select_driver(get_class($this));
 		return parent::__call($method, $args);
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Initialize driver
 	 *
 	 * @return	void
 	 */
 	protected function initialize()
 	{
 		// Overload this method to implement initialization
 	}

 	// ------------------------------------------------------------------------

 	/**
 	 * Save the session data
 	 *
 	 * Data in the array has changed - perform any storage synchronization
 	 * necessary. The child class MUST implement this abstract method!
 	 *
 	 * @return	void
 	 */
 	abstract public function sess_save();

 	// ------------------------------------------------------------------------

 	/**
 	 * Destroy the current session
 	 *
 	 * Clean up storage for this session - it has been terminated.
 	 * The child class MUST implement this abstract method!
 	 *
 	 * @return	void
 	 */
 	abstract public function sess_destroy();

 	// ------------------------------------------------------------------------

 	/**
 	 * Regenerate the current session
 	 *
 	 * Regenerate the session ID.
 	 * The child class MUST implement this abstract method!
 	 *
 	 * @param	bool	Destroy session data flag (default: false)
 	 * @return	void
 	 */
 	abstract public function sess_regenerate($destroy = FALSE);

 	// ------------------------------------------------------------------------

 	/**
 	 * Get a reference to user data array
 	 *
 	 * Give array access to the main CI_Session object.
 	 * The child class MUST implement this abstract method!
 	 *
 	 * @return	array	Reference to userdata
 	 */
 	abstract public function &get_userdata();

 }

 /* End of file Session.php */
 /* Location: ./system/libraries/Session/Session.php */
	<?php
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP 5.2.4 or newer
	*
	* This content is released under the MIT License (MIT)
	*
	* Copyright (c) 2014, British Columbia Institute of Technology
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*
	* @package CodeIgniter
	* @author EllisLab Dev Team
	* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
	* @copyright Copyright (c) 2014, British Columbia Institute of Technology (http://bcit.ca/)
	* @license http://opensource.org/licenses/MIT MIT License
	* @link http://codeigniter.com
	* @since Version 2.0.0
	* @filesource
	*/
	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
	* @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');

	/**
	* 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;

	// ------------------------------------------------------------------------

	/**
	* 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.
	*
	* @param array Configuration parameters
	* @return void
	*/
	public function __construct(array $params = array())
	{
	$_config =& get_instance()->config;

	// No sessions under CLI
	if (is_cli())
	{
	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))
	{
	$drivers = array_map('strtolower', (array) $drivers);
	$this->valid_drivers = array_merge($this->valid_drivers, array_diff($drivers, $this->valid_drivers));
	}

	// Get driver to load
	$driver = isset($params['sess_driver']) ? $params['sess_driver'] : $_config->item('sess_driver');
	if ( ! $driver)
	{
	log_message('debug', "Session: No driver name is configured, defaulting to 'cookie'.");
	$driver = 'cookie';
	}

	if ( ! in_array($driver, $this->valid_drivers))
	{
	log_message('error', 'Session: Configured driver name is not valid, aborting.');
	return;
	}

	// Save a copy of parameters in case drivers need access
	$this->params = $params;

	// Load driver and get array reference
	$this->load_driver($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();

	// Delete expired tempdata
	$this->_tempdata_sweep();

	log_message('debug', 'CI_Session routines successfully run');
	}

	// ------------------------------------------------------------------------

	/**
	* 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;
	}

	// ------------------------------------------------------------------------

	/**
	* 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', $this->valid_drivers)))
	{
	// See if driver is loaded
	if (isset($this->$child))
	{
	// See if driver is already current
	if ($this->$child !== $this->current)
	{
	// Make driver current and sync userdata
	$this->current = $this->$child;
	$this->userdata =& $this->current->get_userdata();
	}
	}
	else
	{
	// Load new driver
	$this->load_driver($child);
	}
	}
	}

	// ------------------------------------------------------------------------

	/**
	* Destroy the current session
	*
	* @return void
	*/
	public function sess_destroy()
	{
	// Just call destroy on driver
	$this->current->sess_destroy();
	}

	// ------------------------------------------------------------------------

	/**
	* 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();
	}

	// ------------------------------------------------------------------------

	/**
	* Fetch a specific item from the session array
	*
	* @param string Item key
	* @return string Item value or NULL if not found
	*/
	public function userdata($item = NULL)
	{
	if (isset($item))
	{
	return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
	}

	return isset($this->userdata) ? $this->userdata : array();
	}

	// ------------------------------------------------------------------------

	/**
	* 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();
	}

	// ------------------------------------------------------------------------

	/**
	* Add or change data in the "userdata" array
	*
	* @param mixed Item name or array of items
	* @param string Item value or empty string
	* @return void
	*/
	public function set_userdata($newdata, $newval = '')
	{
	// Wrap params as array if singular
	if (is_string($newdata))
	{
	$newdata = array($newdata => $newval);
	}

	// Set each name/value pair
	if (count($newdata) > 0)
	{
	foreach ($newdata as $key => $val)
	{
	$this->userdata[$key] = $val;
	}
	}

	// Tell driver data changed
	$this->current->sess_save();
	}

	// ------------------------------------------------------------------------

	/**
	* Delete a session variable from the "userdata" array
	*
	* @param mixed Item name or array of item names
	* @return void
	*/
	public function unset_userdata($newdata)
	{
	// Wrap single name as array
	if (is_string($newdata))
	{
	$newdata = array($newdata => '');
	}

	// Unset each item name
	if (count($newdata) > 0)
	{
	foreach (array_keys($newdata) as $key)
	{
	unset($this->userdata[$key]);
	}
	}

	// Tell driver data changed
	$this->current->sess_save();
	}

	// ------------------------------------------------------------------------

	/**
	* Determine if an item exists
	*
	* @param string Item name
	* @return bool
	*/
	public function has_userdata($item)
	{
	return isset($this->userdata[$item]);
	}

	// ------------------------------------------------------------------------

	/**
	* Add or change flashdata, only available until the next request
	*
	* @param mixed Item name or array of items
	* @param string Item value or empty string
	* @return void
	*/
	public function set_flashdata($newdata, $newval = '')
	{
	// Wrap item as array if singular
	if (is_string($newdata))
	{
	$newdata = array($newdata => $newval);
	}

	// Prepend each key name and set value
	if (count($newdata) > 0)
	{
	foreach ($newdata as $key => $val)
	{
	$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
	$this->set_userdata($flashdata_key, $val);
	}
	}
	}

	// ------------------------------------------------------------------------

	/**
	* Keeps existing flashdata available to next request.
	*
	* @param mixed Item key(s)
	* @return void
	*/
	public function keep_flashdata($key)
	{

	if (is_array($key))
	{
	foreach ($key as $k)
	{
	$this->keep_flashdata($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);
	}

	// ------------------------------------------------------------------------

	/**
	* Fetch a specific flashdata item from the session array
	*
	* @param string Item key
	* @return string
	*/
	public function flashdata($key = NULL)
	{
	if (isset($key))
	{
	return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key);
	}

	// Get our flashdata items from userdata
	$out = array();
	foreach ($this->userdata() as $key => $val)
	{
	if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_OLD) !== FALSE)
	{
	$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_OLD, '', $key);
	$out[$key] = $val;
	}
	}

	return $out;
	}

	// ------------------------------------------------------------------------

	/**
	* Add or change tempdata, only available until expiration
	*
	* @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
	* @return void
	*/
	public function set_tempdata($newdata, $newval = '', $expire = 0)
	{
	// 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();
	}

	// 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);
	}

	// ------------------------------------------------------------------------

	/**
	* Delete a temporary session variable from the "userdata" array
	*
	* @param mixed Item name or array of item names
	* @return void
	*/
	public function unset_tempdata($newdata)
	{
	// 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 => '');
	}

	// 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);
	}

	// ------------------------------------------------------------------------

	/**
	* Fetch a specific tempdata item from the session array
	*
	* @param string Item key
	* @return string
	*/
	public function tempdata($key = NULL)
	{
	if (isset($key))
	{
	return $this->userdata(self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key);
	}

	// Get our tempdata items from userdata
	$out = array();
	foreach ($this->userdata() as $key => $val)
	{
	if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_EXP) !== FALSE)
	{
	$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_EXP, '', $key);
	$out[$key] = $val;
	}
	}

	return $out;
	}

	// ------------------------------------------------------------------------

	/**
	* Identifies flashdata as 'old' for removal
	* when _flashdata_sweep() runs.
	*
	* @return void
	*/
	protected function _flashdata_mark()
	{
	foreach ($this->userdata() as $name => $value)
	{
	$parts = explode(self::FLASHDATA_NEW, $name);
	if (count($parts) === 2)
	{
	$this->set_userdata(self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1], $value);
	$this->unset_userdata($name);
	}
	}
	}

	// ------------------------------------------------------------------------

	/**
	* Removes all flashdata marked as 'old'
	*
	* @return void
	*/
	protected function _flashdata_sweep()
	{
	$userdata = $this->userdata();
	foreach (array_keys($userdata) as $key)
	{
	if (strpos($key, self::FLASHDATA_OLD))
	{
	$this->unset_userdata($key);
	}
	}
	}

	// ------------------------------------------------------------------------

	/**
	* Removes all expired tempdata
	*
	* @return void
	*/
	protected function _tempdata_sweep()
	{
	// 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 $key)
	{
	if (strpos($key, self::FLASHDATA_EXP) && $expirations[$key] < $now)
	{
	unset($expirations[$key]);
	$this->unset_userdata($key);
	}
	}

	// Update expiration list
	$this->set_userdata(self::EXPIRATION_KEY, $expirations);
	}

	}

	// ------------------------------------------------------------------------

	/**
	* 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
	*
	* Gets the CI singleton, so that individual drivers
	* don't have to do it separately.
	*
	* @return void
	*/
	public function __construct()
	{
	$this->CI =& get_instance();
	}

	// ------------------------------------------------------------------------

	/**
	* Decorate
	*
	* Decorates the child with the parent driver lib's methods and properties
	*
	* @param object Parent library object
	* @return void
	*/
	public function decorate($parent)
	{
	// Call base class decorate first
	parent::decorate($parent);

	// Call initialize method now that driver has access to $this->_parent
	$this->initialize();
	}

	// ------------------------------------------------------------------------

	/**
	* __call magic method
	*
	* Handles access to the parent driver library's methods
	*
	* @param string Library method name
	* @param array Method arguments (default: none)
	* @return mixed
	*/
	public function __call($method, $args = array())
	{
	// Make sure the parent library uses this driver
	$this->_parent->select_driver(get_class($this));
	return parent::__call($method, $args);
	}

	// ------------------------------------------------------------------------

	/**
	* Initialize driver
	*
	* @return void
	*/
	protected function initialize()
	{
	// Overload this method to implement initialization
	}

	// ------------------------------------------------------------------------

	/**
	* Save the session data
	*
	* Data in the array has changed - perform any storage synchronization
	* necessary. The child class MUST implement this abstract method!
	*
	* @return void
	*/
	abstract public function sess_save();

	// ------------------------------------------------------------------------

	/**
	* Destroy the current session
	*
	* Clean up storage for this session - it has been terminated.
	* The child class MUST implement this abstract method!
	*
	* @return void
	*/
	abstract public function sess_destroy();

	// ------------------------------------------------------------------------

	/**
	* Regenerate the current session
	*
	* Regenerate the session ID.
	* The child class MUST implement this abstract method!
	*
	* @param bool Destroy session data flag (default: false)
	* @return void
	*/
	abstract public function sess_regenerate($destroy = FALSE);

	// ------------------------------------------------------------------------

	/**
	* Get a reference to user data array
	*
	* Give array access to the main CI_Session object.
	* The child class MUST implement this abstract method!
	*
	* @return array Reference to userdata
	*/
	abstract public function &get_userdata();

	}

	/* End of file Session.php */
	/* Location: ./system/libraries/Session/Session.php */