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

 	/**
 	 * DB object
 	 *
 	 * @var	object
 	 */
 	protected $_db;

 	/**
 	 * Row exists flag
 	 *
 	 * @var	bool
 	 */
 	protected $_row_exists = FALSE;

 	/**
 	 * Lock "driver" flag
 	 *
 	 * @var	string
 	 */
 	protected $_platform;

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

 	/**
 	 * 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.');
 		}
 		elseif ($this->_db->cache_on)
 		{
 			throw new Exception('Configured database connection has cache enabled. Aborting.');
 		}

 		$db_driver = $this->_db->dbdriver.(empty($this->_db->subdriver) ? '' : '_'.$this->_db->subdriver);
 		if (strpos($db_driver, 'mysql') !== FALSE)
 		{
 			$this->_platform = 'mysql';
 		}
 		elseif (in_array($db_driver, array('postgre', 'pdo_pgsql'), TRUE))
 		{
 			$this->_platform = 'postgre';
 		}

 		// Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future.
 		isset($this->_config['save_path']) OR $this->_config['save_path'] = config_item('sess_table_name');
 	}

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

 	/**
 	 * Open
 	 *
 	 * Initializes the database connection
 	 *
 	 * @param	string	$save_path	Table name
 	 * @param	string	$name		Session cookie name, unused
 	 * @return	bool
 	 */
 	public function open($save_path, $name)
 	{
 		if (empty($this->_db->conn_id) && ! $this->_db->db_connect())
 		{
 			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 ($this->_get_lock($session_id) !== FALSE)
 		{
 			// Prevent previous QB calls from messing with our queries
 			$this->_db->reset_query();

 			// Needed by write() to detect session_regenerate_id() calls
 			$this->_session_id = $session_id;

 			$this->_db
 				->select('data')
 				->from($this->_config['save_path'])
 				->where('id', $session_id);

 			if ($this->_config['match_ip'])
 			{
 				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
 			}

 			if (($result = $this->_db->get()->row()) === NULL)
 			{
 				// PHP7 will reuse the same SessionHandler object after
 				// ID regeneration, so we need to explicitly set this to
 				// FALSE instead of relying on the default ...
 				$this->_row_exists = FALSE;
 				$this->_fingerprint = md5('');
 				return '';
 			}

 			// PostgreSQL's variant of a BLOB datatype is Bytea, which is a
 			// PITA to work with, so we use base64-encoded data in a TEXT
 			// field instead.
 			$result = ($this->_platform === 'postgre')
 				? base64_decode(rtrim($result->data))
 				: $result->data;

 			$this->_fingerprint = md5($result);
 			$this->_row_exists = TRUE;
 			return $result;
 		}

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

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

 	/**
 	 * 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)
 	{
 		// Prevent previous QB calls from messing with our queries
 		$this->_db->reset_query();

 		// Was the ID regenerated?
 		if ($session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
 				return $this->_failure;
 			}

 			$this->_row_exists = FALSE;
 			$this->_session_id = $session_id;
 		}
 		elseif ($this->_lock === FALSE)
 		{
 			return $this->_failure;
 		}

 		if ($this->_row_exists === FALSE)
 		{
 			$insert_data = array(
 				'id' => $session_id,
 				'ip_address' => $_SERVER['REMOTE_ADDR'],
 				'timestamp' => time(),
 				'data' => ($this->_platform === 'postgre' ? base64_encode($session_data) : $session_data)
 			);

 			if ($this->_db->insert($this->_config['save_path'], $insert_data))
 			{
 				$this->_fingerprint = md5($session_data);
 				$this->_row_exists = TRUE;
 				return $this->_success;
 			}

 			return $this->_failure;
 		}

 		$this->_db->where('id', $session_id);
 		if ($this->_config['match_ip'])
 		{
 			$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
 		}

 		$update_data = array('timestamp' => time());
 		if ($this->_fingerprint !== md5($session_data))
 		{
 			$update_data['data'] = ($this->_platform === 'postgre')
 				? base64_encode($session_data)
 				: $session_data;
 		}

 		if ($this->_db->update($this->_config['save_path'], $update_data))
 		{
 			$this->_fingerprint = md5($session_data);
 			return $this->_success;
 		}

 		return $this->_failure;
 	}

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

 	/**
 	 * Close
 	 *
 	 * Releases locks
 	 *
 	 * @return	bool
 	 */
 	public function close()
 	{
 		return ($this->_lock && ! $this->_release_lock())
 			? $this->_failure
 			: $this->_success;
 	}

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

 	/**
 	 * Destroy
 	 *
 	 * Destroys the current session.
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @return	bool
 	 */
 	public function destroy($session_id)
 	{
 		if ($this->_lock)
 		{
 			// Prevent previous QB calls from messing with our queries
 			$this->_db->reset_query();

 			$this->_db->where('id', $session_id);
 			if ($this->_config['match_ip'])
 			{
 				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
 			}

 			if ( ! $this->_db->delete($this->_config['save_path']))
 			{
 				return $this->_failure;
 			}
 		}

 		if ($this->close() === $this->_success)
 		{
 			$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)
 	{
 		// Prevent previous QB calls from messing with our queries
 		$this->_db->reset_query();

 		return ($this->_db->delete($this->_config['save_path'], 'timestamp < '.(time() - $maxlifetime)))
 			? $this->_success
 			: $this->_failure;
 	}

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

 	/**
 	 * Get lock
 	 *
 	 * Acquires a lock, depending on the underlying platform.
 	 *
 	 * @param	string	$session_id	Session ID
 	 * @return	bool
 	 */
 	protected function _get_lock($session_id)
 	{
 		if ($this->_platform === 'mysql')
 		{
 			$arg = $session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : '');
 			if ($this->_db->query("SELECT GET_LOCK('".$arg."', 300) AS ci_session_lock")->row()->ci_session_lock)
 			{
 				$this->_lock = $arg;
 				return TRUE;
 			}

 			return FALSE;
 		}
 		elseif ($this->_platform === 'postgre')
 		{
 			$arg = "hashtext('".$session_id."')".($this->_config['match_ip'] ? ", hashtext('".$_SERVER['REMOTE_ADDR']."')" : '');
 			if ($this->_db->simple_query('SELECT pg_advisory_lock('.$arg.')'))
 			{
 				$this->_lock = $arg;
 				return TRUE;
 			}

 			return FALSE;
 		}

 		return parent::_get_lock($session_id);
 	}

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

 	/**
 	 * Release lock
 	 *
 	 * Releases a previously acquired lock
 	 *
 	 * @return	bool
 	 */
 	protected function _release_lock()
 	{
 		if ( ! $this->_lock)
 		{
 			return TRUE;
 		}

 		if ($this->_platform === 'mysql')
 		{
 			if ($this->_db->query("SELECT RELEASE_LOCK('".$this->_lock."') AS ci_session_lock")->row()->ci_session_lock)
 			{
 				$this->_lock = FALSE;
 				return TRUE;
 			}

 			return FALSE;
 		}
 		elseif ($this->_platform === 'postgre')
 		{
 			if ($this->_db->simple_query('SELECT pg_advisory_unlock('.$this->_lock.')'))
 			{
 				$this->_lock = FALSE;
 				return TRUE;
 			}

 			return FALSE;
 		}

 		return parent::_release_lock();
 	}

 }
	<?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 Database Driver
	*
	* @package CodeIgniter
	* @subpackage Libraries
	* @category Sessions
	* @author Andrey Andreev
	* @link https://codeigniter.com/user_guide/libraries/sessions.html
	*/
	class CI_Session_database_driver extends CI_Session_driver implements SessionHandlerInterface {

	/**
	* DB object
	*
	* @var object
	*/
	protected $_db;

	/**
	* Row exists flag
	*
	* @var bool
	*/
	protected $_row_exists = FALSE;

	/**
	* Lock "driver" flag
	*
	* @var string
	*/
	protected $_platform;

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

	/**
	* 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.');
	}
	elseif ($this->_db->cache_on)
	{
	throw new Exception('Configured database connection has cache enabled. Aborting.');
	}

	$db_driver = $this->_db->dbdriver.(empty($this->_db->subdriver) ? '' : '_'.$this->_db->subdriver);
	if (strpos($db_driver, 'mysql') !== FALSE)
	{
	$this->_platform = 'mysql';
	}
	elseif (in_array($db_driver, array('postgre', 'pdo_pgsql'), TRUE))
	{
	$this->_platform = 'postgre';
	}

	// Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future.
	isset($this->_config['save_path']) OR $this->_config['save_path'] = config_item('sess_table_name');
	}

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

	/**
	* Open
	*
	* Initializes the database connection
	*
	* @param string $save_path Table name
	* @param string $name Session cookie name, unused
	* @return bool
	*/
	public function open($save_path, $name)
	{
	if (empty($this->_db->conn_id) && ! $this->_db->db_connect())
	{
	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 ($this->_get_lock($session_id) !== FALSE)
	{
	// Prevent previous QB calls from messing with our queries
	$this->_db->reset_query();

	// Needed by write() to detect session_regenerate_id() calls
	$this->_session_id = $session_id;

	$this->_db
	->select('data')
	->from($this->_config['save_path'])
	->where('id', $session_id);

	if ($this->_config['match_ip'])
	{
	$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
	}

	if (($result = $this->_db->get()->row()) === NULL)
	{
	// PHP7 will reuse the same SessionHandler object after
	// ID regeneration, so we need to explicitly set this to
	// FALSE instead of relying on the default ...
	$this->_row_exists = FALSE;
	$this->_fingerprint = md5('');
	return '';
	}

	// PostgreSQL's variant of a BLOB datatype is Bytea, which is a
	// PITA to work with, so we use base64-encoded data in a TEXT
	// field instead.
	$result = ($this->_platform === 'postgre')
	? base64_decode(rtrim($result->data))
	: $result->data;

	$this->_fingerprint = md5($result);
	$this->_row_exists = TRUE;
	return $result;
	}

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

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

	/**
	* 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)
	{
	// Prevent previous QB calls from messing with our queries
	$this->_db->reset_query();

	// Was the ID regenerated?
	if ($session_id !== $this->_session_id)
	{
	if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
	{
	return $this->_failure;
	}

	$this->_row_exists = FALSE;
	$this->_session_id = $session_id;
	}
	elseif ($this->_lock === FALSE)
	{
	return $this->_failure;
	}

	if ($this->_row_exists === FALSE)
	{
	$insert_data = array(
	'id' => $session_id,
	'ip_address' => $_SERVER['REMOTE_ADDR'],
	'timestamp' => time(),
	'data' => ($this->_platform === 'postgre' ? base64_encode($session_data) : $session_data)
	);

	if ($this->_db->insert($this->_config['save_path'], $insert_data))
	{
	$this->_fingerprint = md5($session_data);
	$this->_row_exists = TRUE;
	return $this->_success;
	}

	return $this->_failure;
	}

	$this->_db->where('id', $session_id);
	if ($this->_config['match_ip'])
	{
	$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
	}

	$update_data = array('timestamp' => time());
	if ($this->_fingerprint !== md5($session_data))
	{
	$update_data['data'] = ($this->_platform === 'postgre')
	? base64_encode($session_data)
	: $session_data;
	}

	if ($this->_db->update($this->_config['save_path'], $update_data))
	{
	$this->_fingerprint = md5($session_data);
	return $this->_success;
	}

	return $this->_failure;
	}

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

	/**
	* Close
	*
	* Releases locks
	*
	* @return bool
	*/
	public function close()
	{
	return ($this->_lock && ! $this->_release_lock())
	? $this->_failure
	: $this->_success;
	}

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

	/**
	* Destroy
	*
	* Destroys the current session.
	*
	* @param string $session_id Session ID
	* @return bool
	*/
	public function destroy($session_id)
	{
	if ($this->_lock)
	{
	// Prevent previous QB calls from messing with our queries
	$this->_db->reset_query();

	$this->_db->where('id', $session_id);
	if ($this->_config['match_ip'])
	{
	$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
	}

	if ( ! $this->_db->delete($this->_config['save_path']))
	{
	return $this->_failure;
	}
	}

	if ($this->close() === $this->_success)
	{
	$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)
	{
	// Prevent previous QB calls from messing with our queries
	$this->_db->reset_query();

	return ($this->_db->delete($this->_config['save_path'], 'timestamp < '.(time() - $maxlifetime)))
	? $this->_success
	: $this->_failure;
	}

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

	/**
	* Get lock
	*
	* Acquires a lock, depending on the underlying platform.
	*
	* @param string $session_id Session ID
	* @return bool
	*/
	protected function _get_lock($session_id)
	{
	if ($this->_platform === 'mysql')
	{
	$arg = $session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : '');
	if ($this->_db->query("SELECT GET_LOCK('".$arg."', 300) AS ci_session_lock")->row()->ci_session_lock)
	{
	$this->_lock = $arg;
	return TRUE;
	}

	return FALSE;
	}
	elseif ($this->_platform === 'postgre')
	{
	$arg = "hashtext('".$session_id."')".($this->_config['match_ip'] ? ", hashtext('".$_SERVER['REMOTE_ADDR']."')" : '');
	if ($this->_db->simple_query('SELECT pg_advisory_lock('.$arg.')'))
	{
	$this->_lock = $arg;
	return TRUE;
	}

	return FALSE;
	}

	return parent::_get_lock($session_id);
	}

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

	/**
	* Release lock
	*
	* Releases a previously acquired lock
	*
	* @return bool
	*/
	protected function _release_lock()
	{
	if ( ! $this->_lock)
	{
	return TRUE;
	}

	if ($this->_platform === 'mysql')
	{
	if ($this->_db->query("SELECT RELEASE_LOCK('".$this->_lock."') AS ci_session_lock")->row()->ci_session_lock)
	{
	$this->_lock = FALSE;
	return TRUE;
	}

	return FALSE;
	}
	elseif ($this->_platform === 'postgre')
	{
	if ($this->_db->simple_query('SELECT pg_advisory_unlock('.$this->_lock.')'))
	{
	$this->_lock = FALSE;
	return TRUE;
	}

	return FALSE;
	}

	return parent::_release_lock();
	}

	}