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

 <?php
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP
  *
  * This content is released under the MIT License (MIT)
  *
  * Copyright (c) 2014 - 2016, 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 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
 defined('BASEPATH') OR exit('No direct script access allowed');

 /**
  * CodeIgniter Session Memcached Driver
  *
  * @package	CodeIgniter
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
  * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session_memcached_driver extends CI_Session_driver implements SessionHandlerInterface {

 	/**
 	 * Memcached instance
 	 *
 	 * @var	Memcached
 	 */
 	protected $_memcached;

 	/**
 	 * Key prefix
 	 *
 	 * @var	string
 	 */
 	protected $_key_prefix = 'ci_session:';

 	/**
 	 * Lock key
 	 *
 	 * @var	string
 	 */
 	protected $_lock_key;

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

 	/**
 	 * Class constructor
 	 *
 	 * @param	array	$params	Configuration parameters
 	 * @return	void
 	 */
 	public function __construct(&$params)
 	{
 		parent::__construct($params);

 		if (empty($this->_config['save_path']))
 		{
 			log_message('error', 'Session: No Memcached save path configured.');
 		}

 		if ($this->_config['match_ip'] === TRUE)
 		{
 			$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
 		}
 	}

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

 	/**
 	 * Open
 	 *
 	 * Sanitizes save_path and initializes connections.
 	 *
 	 * @param	string	$save_path	Server path(s)
 	 * @param	string	$name		Session cookie name, unused
 	 * @return	bool
 	 */
 	public function open($save_path, $name)
 	{
 		$this->_memcached = new Memcached();
 		$this->_memcached->setOption(Memcached::OPT_BINARY_PROTOCOL, TRUE); // required for touch() usage
 		$server_list = array();
 		foreach ($this->_memcached->getServerList() as $server)
 		{
 			$server_list[] = $server['host'].':'.$server['port'];
 		}

 		if ( ! preg_match_all('#,?([^,:]+)\:(\d{1,5})(?:\:(\d+))?#', $this->_config['save_path'], $matches, PREG_SET_ORDER))
 		{
 			$this->_memcached = NULL;
 			log_message('error', 'Session: Invalid Memcached save path format: '.$this->_config['save_path']);
 			return $this->_failure;
 		}

 		foreach ($matches as $match)
 		{
 			// If Memcached already has this server (or if the port is invalid), skip it
 			if (in_array($match[1].':'.$match[2], $server_list, TRUE))
 			{
 				log_message('debug', 'Session: Memcached server pool already has '.$match[1].':'.$match[2]);
 				continue;
 			}

 			if ( ! $this->_memcached->addServer($match[1], $match[2], isset($match[3]) ? $match[3] : 0))
 			{
 				log_message('error', 'Could not add '.$match[1].':'.$match[2].' to Memcached server pool.');
 			}
 			else
 			{
 				$server_list[] = $match[1].':'.$match[2];
 			}
 		}

 		if (empty($server_list))
 		{
 			log_message('error', 'Session: Memcached server pool is empty.');
 			return $this->_failure;
 		}

 		return $this->_success;
 	}

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

 	/**
 	 * Read
 	 *
 	 * Reads session data and acquires a lock
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @return	string	Serialized session data
 	 */
 	public function read($session_id)
 	{
 		if (isset($this->_memcached) && $this->_get_lock($session_id))
 		{
 			// Needed by write() to detect session_regenerate_id() calls
 			$this->_session_id = $session_id;

 			$session_data = (string) $this->_memcached->get($this->_key_prefix.$session_id);
 			$this->_fingerprint = md5($session_data);
 			return $session_data;
 		}

 		return $this->_failure;
 	}

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

 	/**
 	 * Write
 	 *
 	 * Writes (create / update) session data
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @param	string	$session_data	Serialized session data
 	 * @return	bool
 	 */
 	public function write($session_id, $session_data)
 	{
 		if ( ! isset($this->_memcached))
 		{
 			return $this->_failure;
 		}
 		// Was the ID regenerated?
 		elseif ($session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
 				return $this->_failure;
 			}

 			$this->_fingerprint = md5('');
 			$this->_session_id = $session_id;
 		}

 		if (isset($this->_lock_key))
 		{
 			$this->_memcached->replace($this->_lock_key, time(), 300);
 			if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
 			{
 				if ($this->_memcached->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
 				{
 					$this->_fingerprint = $fingerprint;
 					return $this->_success;
 				}

 				return $this->_failure;
 			}

 			return $this->_memcached->touch($this->_key_prefix.$session_id, $this->_config['expiration'])
 				? $this->_success
 				: $this->_failure;
 		}

 		return $this->_failure;
 	}

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

 	/**
 	 * Close
 	 *
 	 * Releases locks and closes connection.
 	 *
 	 * @return	bool
 	 */
 	public function close()
 	{
 		if (isset($this->_memcached))
 		{
 			isset($this->_lock_key) && $this->_memcached->delete($this->_lock_key);
 			if ( ! $this->_memcached->quit())
 			{
 				return $this->_failure;
 			}

 			$this->_memcached = NULL;
 			return $this->_success;
 		}

 		return $this->_failure;
 	}

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

 	/**
 	 * Destroy
 	 *
 	 * Destroys the current session.
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @return	bool
 	 */
 	public function destroy($session_id)
 	{
 		if (isset($this->_memcached, $this->_lock_key))
 		{
 			$this->_memcached->delete($this->_key_prefix.$session_id);
 			$this->_cookie_destroy();
 			return $this->_success;
 		}

 		return $this->_failure;
 	}

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

 	/**
 	 * Garbage Collector
 	 *
 	 * Deletes expired sessions
 	 *
 	 * @param	int 	$maxlifetime	Maximum lifetime of sessions
 	 * @return	bool
 	 */
 	public function gc($maxlifetime)
 	{
 		// Not necessary, Memcached takes care of that.
 		return $this->_success;
 	}

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

 	/**
 	 * Get lock
 	 *
 	 * Acquires an (emulated) lock.
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @return	bool
 	 */
 	protected function _get_lock($session_id)
 	{
 		// PHP 7 reuses the SessionHandler object on regeneration,
 		// so we need to check here if the lock key is for the
 		// correct session ID.
 		if ($this->_lock_key === $this->_key_prefix.$session_id.':lock')
 		{
 			return ($this->_memcached->replace($this->_lock_key, time(), 300))
 				? $this->_success
 				: $this->_failure;
 		}

 		// 30 attempts to obtain a lock, in case another request already has it
 		$lock_key = $this->_key_prefix.$session_id.':lock';
 		$attempt = 0;
 		do
 		{
 			if ($this->_memcached->get($lock_key))
 			{
 				sleep(1);
 				continue;
 			}

 			if ( ! $this->_memcached->set($lock_key, time(), 300))
 			{
 				log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
 				return $this->_failure;
 			}

 			$this->_lock_key = $lock_key;
 			break;
 		}
 		while (++$attempt < 30);

 		if ($attempt === 30)
 		{
 			log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 30 attempts, aborting.');
 			return $this->_failure;
 		}

 		$this->_lock = TRUE;
 		return $this->_success;
 	}

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

 	/**
 	 * Release lock
 	 *
 	 * Releases a previously acquired lock
 	 *
 	 * @return	bool
 	 */
 	protected function _release_lock()
 	{
 		if (isset($this->_memcached, $this->_lock_key) && $this->_lock)
 		{
 			if ( ! $this->_memcached->delete($this->_lock_key) && $this->_memcached->getResultCode() !== Memcached::RES_NOTFOUND)
 			{
 				log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
 				return FALSE;
 			}

 			$this->_lock_key = NULL;
 			$this->_lock = FALSE;
 		}

 		return TRUE;
 	}

 }
	<?php
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP
	*
	* This content is released under the MIT License (MIT)
	*
	* Copyright (c) 2014 - 2016, 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 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
	* @license http://opensource.org/licenses/MIT MIT License
	* @link https://codeigniter.com
	* @since Version 3.0.0
	* @filesource
	*/
	defined('BASEPATH') OR exit('No direct script access allowed');

	/**
	* CodeIgniter Session Memcached Driver
	*
	* @package CodeIgniter
	* @subpackage Libraries
	* @category Sessions
	* @author Andrey Andreev
	* @link https://codeigniter.com/user_guide/libraries/sessions.html
	*/
	class CI_Session_memcached_driver extends CI_Session_driver implements SessionHandlerInterface {

	/**
	* Memcached instance
	*
	* @var Memcached
	*/
	protected $_memcached;

	/**
	* Key prefix
	*
	* @var string
	*/
	protected $_key_prefix = 'ci_session:';

	/**
	* Lock key
	*
	* @var string
	*/
	protected $_lock_key;

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

	/**
	* Class constructor
	*
	* @param array $params Configuration parameters
	* @return void
	*/
	public function __construct(&$params)
	{
	parent::__construct($params);

	if (empty($this->_config['save_path']))
	{
	log_message('error', 'Session: No Memcached save path configured.');
	}

	if ($this->_config['match_ip'] === TRUE)
	{
	$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
	}
	}

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

	/**
	* Open
	*
	* Sanitizes save_path and initializes connections.
	*
	* @param string $save_path Server path(s)
	* @param string $name Session cookie name, unused
	* @return bool
	*/
	public function open($save_path, $name)
	{
	$this->_memcached = new Memcached();
	$this->_memcached->setOption(Memcached::OPT_BINARY_PROTOCOL, TRUE); // required for touch() usage
	$server_list = array();
	foreach ($this->_memcached->getServerList() as $server)
	{
	$server_list[] = $server['host'].':'.$server['port'];
	}

	if ( ! preg_match_all('#,?([^,:]+)\:(\d{1,5})(?:\:(\d+))?#', $this->_config['save_path'], $matches, PREG_SET_ORDER))
	{
	$this->_memcached = NULL;
	log_message('error', 'Session: Invalid Memcached save path format: '.$this->_config['save_path']);
	return $this->_failure;
	}

	foreach ($matches as $match)
	{
	// If Memcached already has this server (or if the port is invalid), skip it
	if (in_array($match[1].':'.$match[2], $server_list, TRUE))
	{
	log_message('debug', 'Session: Memcached server pool already has '.$match[1].':'.$match[2]);
	continue;
	}

	if ( ! $this->_memcached->addServer($match[1], $match[2], isset($match[3]) ? $match[3] : 0))
	{
	log_message('error', 'Could not add '.$match[1].':'.$match[2].' to Memcached server pool.');
	}
	else
	{
	$server_list[] = $match[1].':'.$match[2];
	}
	}

	if (empty($server_list))
	{
	log_message('error', 'Session: Memcached server pool is empty.');
	return $this->_failure;
	}

	return $this->_success;
	}

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

	/**
	* Read
	*
	* Reads session data and acquires a lock
	*
	* @param string $session_id Session ID
	* @return string Serialized session data
	*/
	public function read($session_id)
	{
	if (isset($this->_memcached) && $this->_get_lock($session_id))
	{
	// Needed by write() to detect session_regenerate_id() calls
	$this->_session_id = $session_id;

	$session_data = (string) $this->_memcached->get($this->_key_prefix.$session_id);
	$this->_fingerprint = md5($session_data);
	return $session_data;
	}

	return $this->_failure;
	}

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

	/**
	* Write
	*
	* Writes (create / update) session data
	*
	* @param string $session_id Session ID
	* @param string $session_data Serialized session data
	* @return bool
	*/
	public function write($session_id, $session_data)
	{
	if ( ! isset($this->_memcached))
	{
	return $this->_failure;
	}
	// Was the ID regenerated?
	elseif ($session_id !== $this->_session_id)
	{
	if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
	{
	return $this->_failure;
	}

	$this->_fingerprint = md5('');
	$this->_session_id = $session_id;
	}

	if (isset($this->_lock_key))
	{
	$this->_memcached->replace($this->_lock_key, time(), 300);
	if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
	{
	if ($this->_memcached->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
	{
	$this->_fingerprint = $fingerprint;
	return $this->_success;
	}

	return $this->_failure;
	}

	return $this->_memcached->touch($this->_key_prefix.$session_id, $this->_config['expiration'])
	? $this->_success
	: $this->_failure;
	}

	return $this->_failure;
	}

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

	/**
	* Close
	*
	* Releases locks and closes connection.
	*
	* @return bool
	*/
	public function close()
	{
	if (isset($this->_memcached))
	{
	isset($this->_lock_key) && $this->_memcached->delete($this->_lock_key);
	if ( ! $this->_memcached->quit())
	{
	return $this->_failure;
	}

	$this->_memcached = NULL;
	return $this->_success;
	}

	return $this->_failure;
	}

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

	/**
	* Destroy
	*
	* Destroys the current session.
	*
	* @param string $session_id Session ID
	* @return bool
	*/
	public function destroy($session_id)
	{
	if (isset($this->_memcached, $this->_lock_key))
	{
	$this->_memcached->delete($this->_key_prefix.$session_id);
	$this->_cookie_destroy();
	return $this->_success;
	}

	return $this->_failure;
	}

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

	/**
	* Garbage Collector
	*
	* Deletes expired sessions
	*
	* @param int $maxlifetime Maximum lifetime of sessions
	* @return bool
	*/
	public function gc($maxlifetime)
	{
	// Not necessary, Memcached takes care of that.
	return $this->_success;
	}

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

	/**
	* Get lock
	*
	* Acquires an (emulated) lock.
	*
	* @param string $session_id Session ID
	* @return bool
	*/
	protected function _get_lock($session_id)
	{
	// PHP 7 reuses the SessionHandler object on regeneration,
	// so we need to check here if the lock key is for the
	// correct session ID.
	if ($this->_lock_key === $this->_key_prefix.$session_id.':lock')
	{
	return ($this->_memcached->replace($this->_lock_key, time(), 300))
	? $this->_success
	: $this->_failure;
	}

	// 30 attempts to obtain a lock, in case another request already has it
	$lock_key = $this->_key_prefix.$session_id.':lock';
	$attempt = 0;
	do
	{
	if ($this->_memcached->get($lock_key))
	{
	sleep(1);
	continue;
	}

	if ( ! $this->_memcached->set($lock_key, time(), 300))
	{
	log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
	return $this->_failure;
	}

	$this->_lock_key = $lock_key;
	break;
	}
	while (++$attempt < 30);

	if ($attempt === 30)
	{
	log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 30 attempts, aborting.');
	return $this->_failure;
	}

	$this->_lock = TRUE;
	return $this->_success;
	}

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

	/**
	* Release lock
	*
	* Releases a previously acquired lock
	*
	* @return bool
	*/
	protected function _release_lock()
	{
	if (isset($this->_memcached, $this->_lock_key) && $this->_lock)
	{
	if ( ! $this->_memcached->delete($this->_lock_key) && $this->_memcached->getResultCode() !== Memcached::RES_NOTFOUND)
	{
	log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
	return FALSE;
	}

	$this->_lock_key = NULL;
	$this->_lock = FALSE;
	}

	return TRUE;
	}

	}