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<?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; }}
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