1: <?php
  2: /**
  3:  * Database Session save handler.  Allows saving session information into a model.
  4:  *
  5:  * PHP 5
  6:  *
  7:  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
  8:  * Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
  9:  *
 10:  * Licensed under The MIT License
 11:  * Redistributions of files must retain the above copyright notice.
 12:  *
 13:  * @copyright     Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 14:  * @link          http://cakephp.org CakePHP(tm) Project
 15:  * @package       Cake.Model.Datasource.Session
 16:  * @since         CakePHP(tm) v 2.0
 17:  * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 18:  */
 19: /**
 20:  * DatabaseSession provides methods to be used with CakeSession.
 21:  *
 22:  * @package       Cake.Model.Datasource.Session
 23:  */
 24: class DatabaseSession implements CakeSessionHandlerInterface {
 25: 
 26: /**
 27:  * Reference to the model handling the session data
 28:  *
 29:  * @var Model
 30:  */
 31:     protected $_model;
 32: 
 33: /**
 34:  * Number of seconds to mark the session as expired
 35:  *
 36:  * @var int
 37:  */
 38:     protected $_timeout;
 39: 
 40: /**
 41:  * Constructor.  Looks at Session configuration information and
 42:  * sets up the session model.
 43:  *
 44:  */
 45:     public function __construct() {
 46:         $modelName = Configure::read('Session.handler.model');
 47: 
 48:         if (empty($modelName)) {
 49:             $settings = array(
 50:                 'class' => 'Session',
 51:                 'alias' => 'Session',
 52:                 'table' => 'cake_sessions',
 53:             );
 54:         } else {
 55:             $settings = array(
 56:                 'class' => $modelName,
 57:                 'alias' => 'Session',
 58:             );
 59:         }
 60:         $this->_model = ClassRegistry::init($settings);
 61:         $this->_timeout = Configure::read('Session.timeout') * 60;
 62:     }
 63: 
 64: /**
 65:  * Method called on open of a database session.
 66:  *
 67:  * @return boolean Success
 68:  */
 69:     public function open() {
 70:         return true;
 71:     }
 72: 
 73: /**
 74:  * Method called on close of a database session.
 75:  *
 76:  * @return boolean Success
 77:  */
 78:     public function close() {
 79:         $probability = mt_rand(1, 150);
 80:         if ($probability <= 3) {
 81:             $this->gc();
 82:         }
 83:         return true;
 84:     }
 85: 
 86: /**
 87:  * Method used to read from a database session.
 88:  *
 89:  * @param mixed $id The key of the value to read
 90:  * @return mixed The value of the key or false if it does not exist
 91:  */
 92:     public function read($id) {
 93:         $row = $this->_model->find('first', array(
 94:             'conditions' => array($this->_model->primaryKey => $id)
 95:         ));
 96: 
 97:         if (empty($row[$this->_model->alias]['data'])) {
 98:             return false;
 99:         }
100: 
101:         return $row[$this->_model->alias]['data'];
102:     }
103: 
104: /**
105:  * Helper function called on write for database sessions.
106:  *
107:  * @param integer $id ID that uniquely identifies session in database
108:  * @param mixed $data The value of the data to be saved.
109:  * @return boolean True for successful write, false otherwise.
110:  */
111:     public function write($id, $data) {
112:         if (!$id) {
113:             return false;
114:         }
115:         $expires = time() + $this->_timeout;
116:         $record = compact('id', 'data', 'expires');
117:         $record[$this->_model->primaryKey] = $id;
118:         return $this->_model->save($record);
119:     }
120: 
121: /**
122:  * Method called on the destruction of a database session.
123:  *
124:  * @param integer $id ID that uniquely identifies session in database
125:  * @return boolean True for successful delete, false otherwise.
126:  */
127:     public function destroy($id) {
128:         return $this->_model->delete($id);
129:     }
130: 
131: /**
132:  * Helper function called on gc for database sessions.
133:  *
134:  * @param integer $expires Timestamp (defaults to current time)
135:  * @return boolean Success
136:  */
137:     public function gc($expires = null) {
138:         if (!$expires) {
139:             $expires = time();
140:         }
141:         return $this->_model->deleteAll(array($this->_model->alias . ".expires <" => $expires), false, false);
142:     }
143: 
144: /**
145:  * Closes the session before the objects handling it become unavailable
146:  *
147:  * @return void
148:  */
149:     public function __destruct() {
150:         session_write_close();
151:     }
152: }
153: