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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 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)) { $this->_platform = 'postgre'; }
// Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future.
if ( ! isset($this->_config['save_path']) && ($this->_config['save_path'] = config_item('sess_table_name'))) { log_message('debug', 'Session: "sess_save_path" is empty; using BC fallback to "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->_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 ($this->_get_lock($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 = $this->_db->get()) OR ($result = $result->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
$this->_db->reset_query();
// Was the ID regenerated?
if (isset($this->_session_id) && $session_id !== $this->_session_id) { if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id)) { return $this->_fail(); }
$this->_row_exists = FALSE; $this->_session_id = $session_id; } elseif ($this->_lock === FALSE) { return $this->_fail(); }
if ($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->_fail(); }
$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 $this->_fail(); }
// ------------------------------------------------------------------------
/** * Close * * Releases locks * * @return bool */ public function close() { return ($this->_lock && ! $this->_release_lock()) ? $this->_fail() : $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 $this->_fail(); } }
if ($this->close() === $this->_success) { $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) { // 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->_fail(); }
// ------------------------------------------------------------------------
/** * 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') { $arg = md5($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(); }}
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