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application/libraries/MY_Session.php

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+<?php defined('BASEPATH') OR exit('No direct script access allowed');
+/**
+ *	Native Session using Memcached
+ *
+ *	Another session library extension that uses Native PHP session
+ *	mechanism instead of the original Codeigniter cookie-based way.
+ *	It also takes memcached as the session data storage, which will
+ *	boost the performance of your app.
+ *
+ *
+ *	@package    CodeIgniter
+ *	@subpackage Libraries
+ *	@category   Libraries
+ *	@author     Saturn <yangg.hu@gmail.com>
+ *	@license    The MIT license
+ *	@link       https://github.com/cnsaturn/codeigniter-my-session
+ */
+
+// Set session configs...
+new Cache_Session_Handler;
+session_start();
+
+Class MY_Session Extends CI_Session
+{
+	/**
+	 * Session Constructor
+	 *
+	 * The constructor runs the session routines automatically
+	 * whenever the class is instantiated.
+	 */
+	public function __construct($params = array())
+	{
+		parent::__construct($params);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch the current session data if it exists
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	public function sess_read()
+	{
+		// Fetch the cookie
+		$session = $_SESSION;
+
+		// Is the session data we unserialized an array with the correct format?
+		if ( ! is_array($session) OR ! isset($session['session_id']) OR ! isset($session['ip_address']) OR ! isset($session['user_agent']) OR ! isset($session['last_activity']))
+		{
+			log_message('debug', 'A session was not found.');
+			$this->sess_destroy(FALSE);
+			return FALSE;
+		}
+
+		// Is the session current?
+		if (($session['last_activity'] + $this->sess_expiration) < $this->now)
+		{
+			$this->sess_destroy(FALSE);
+			return FALSE;
+		}
+
+		// Does the IP Match?
+		if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address())
+		{
+			$this->sess_destroy(FALSE);
+			return FALSE;
+		}
+
+		// Does the User Agent Match?
+		if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 120)))
+		{
+			$this->sess_destroy(FALSE);
+			return FALSE;
+		}
+
+		// Session is valid!
+		$this->userdata = $session;
+		unset($session);
+
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Write the session data
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_write()
+	{
+		// set the custom userdata, the session data we will set in a second
+		$_SESSION = array();
+		foreach($this->userdata as $key => $val)
+		{
+			$_SESSION[$key] = $val;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Create a new session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_create()
+	{
+		if(session_id() == '')
+		{
+			session_start();
+		}
+
+		$_SESSION['session_id']		= session_id();
+		$_SESSION['ip_address']		= $this->CI->input->ip_address();
+		$_SESSION['user_agent']		= substr($this->CI->input->user_agent(), 0, 120);
+		$_SESSION['last_activity']	= $this->now;
+
+		$this->userdata = $_SESSION;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Update an existing session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_update()
+	{
+		// We only update the session every five minutes by default
+		if(($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
+		{
+			return;
+		}
+
+		// Regenerate session id
+		session_regenerate_id();
+
+		// Update the session data in the session data array
+		$this->userdata['session_id'] = session_id();
+		$this->userdata['last_activity'] = $this->now;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_destroy($destroy = TRUE)
+	{
+		session_unset();
+		session_regenerate_id();
+
+		if($destroy)
+		{
+			session_destroy();
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Does nothing for native sessions
+	 *
+	 * @access public
+	 * @return void
+	 */
+	public function _sess_gc(){}
+}
+
+// Customize the PHP Session handler
+// @see http://php.net/manual/en/function.session-set-save-handler.php
+class Cache_Session_Handler
+{
+	private $_lifetime = 0;
+	private $_CI;
+
+	public function __construct()
+	{
+		session_name(config_item('sess_cookie_name'));
+
+		session_set_save_handler(
+			array($this, "open"),
+			array($this, "close"),
+			array($this, "read"),
+			array($this, "write"),
+			array($this, "destroy"),
+			array($this, "gc")
+		);
+
+		// Ref the 'CI' super global object
+		$this->_CI = & get_instance();
+
+		if( ! $this->_CI->load->is_loaded('cache'))
+		{
+			// Make sure your 2.0+ CI Cache driver library is loaded
+			// and set as the primary cache solution
+			$this->_CI->load->driver(
+				'cache',
+				array('adapter' => 'memcached', 'backup' => 'file'
+			));
+		}
+	}
+
+	public function open()
+	{
+		$this->_lifetime = ini_get('session.gc_maxlifetime');
+		if($this->_lifetime <= config_item('sess_expiration'))
+		{
+			$this->_lifetime = config_item('sess_expiration');
+		}
+
+		return TRUE;
+	}
+
+	public function read($id)
+	{
+		return $this->_CI->cache->get("sess_{$id}");
+	}
+
+	public function write($id, $data)
+	{
+		return $this->_CI->cache->replace("sess_{$id}", $data, $this->_lifetime);
+	}
+
+	public function destroy($id)
+	{
+		return $this->_CI->cache->delete("sess_{$id}");
+	}
+
+	public function gc()
+	{
+		return TRUE;
+	}
+
+	public function close()
+	{
+		return TRUE;
+	}
+
+	public function __destruct()
+	{
+		session_write_close();
+	}
+}