diff options
Diffstat (limited to 'system/libraries/Session/drivers/Session_memcached_driver.php')
| -rw-r--r-- | system/libraries/Session/drivers/Session_memcached_driver.php | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php new file mode 100644 index 000000000..2556bf0f7 --- /dev/null +++ b/system/libraries/Session/drivers/Session_memcached_driver.php @@ -0,0 +1,375 @@ +<?php +/** + * CodeIgniter + * + * An open source application development framework for PHP + * + * This content is released under the MIT License (MIT) + * + * Copyright (c) 2014 - 2017, 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. (https://ellislab.com/) + * @copyright Copyright (c) 2014 - 2017, 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 $this->_fail(); + } + + foreach ($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->_fail(); + } + + 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->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * 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, $this->_lock_key)) + { + return $this->_fail(); + } + // Was the ID regenerated? + elseif ($session_id !== $this->_session_id) + { + if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id)) + { + return $this->_fail(); + } + + $this->_fingerprint = md5(''); + $this->_session_id = $session_id; + } + + $key = $this->_key_prefix.$session_id; + + $this->_memcached->replace($this->_lock_key, time(), 300); + if ($this->_fingerprint !== ($fingerprint = md5($session_data))) + { + if ($this->_memcached->set($key, $session_data, $this->_config['expiration'])) + { + $this->_fingerprint = $fingerprint; + return $this->_success; + } + + return $this->_fail(); + } + elseif ( + $this->_memcached->touch($key, $this->_config['expiration']) + OR ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND && $this->_memcached->set($key, $session_data, $this->_config['expiration'])) + ) + { + return $this->_success; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * Close + * + * Releases locks and closes connection. + * + * @return bool + */ + public function close() + { + if (isset($this->_memcached)) + { + $this->_release_lock(); + if ( ! $this->_memcached->quit()) + { + return $this->_fail(); + } + + $this->_memcached = NULL; + return $this->_success; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * 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->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * 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') + { + if ( ! $this->_memcached->replace($this->_lock_key, time(), 300)) + { + return ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND) + ? $this->_memcached->set($this->_lock_key, time(), 300) + : FALSE; + } + } + + // 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 FALSE; + } + + $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 FALSE; + } + + $this->_lock = TRUE; + return TRUE; + } + + // ------------------------------------------------------------------------ + + /** + * Release lock + * + * Releases a previously acquired lock + * + * @return bool + */ + protected function _release_lock() + { + if (isset($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; + } +} |