lib/AkDbSession.php

   1 <?php
   2 /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
   3
   4 // +----------------------------------------------------------------------+
   5 // | Akelos Framework - http://www.akelos.org                             |
   6 // +----------------------------------------------------------------------+
   7 // | Copyright (c) 2002-2006, Akelos Media, S.L.  & Bermi Ferrer Martinez |
   8 // | Released under the GNU Lesser General Public License, see LICENSE.txt|
   9 // +----------------------------------------------------------------------+
  10
  11 /**
  12  * @package ActionController
  13  * @subpackage Sessions
  14  * @author Bermi Ferrer <bermi a.t akelos c.om>
  15  * @copyright Copyright (c) 2002-2006, Akelos Media, S.L. http://www.akelos.org
  16  * @license GNU Lesser General Public License <http://www.gnu.org/copyleft/lesser.html>
  17  */
  18
  19 if(!defined('AK_DBSESSION_CLASS_INCLUDED')){ define('AK_DBSESSION_CLASS_INCLUDED',true); // Class overriding trick
  20
  21
  22 require_once(AK_LIB_DIR.DS.'Ak.php');
  23 require_once(AK_LIB_DIR.DS.'AkObject.php');
  24
  25
  26 /**
  27 * Database based session.
  28 *
  29 * This class enables saving sessions into a database. This can
  30 * be usefull for multiple server sites, and to have more
  31 * control over sessions.
  32 *
  33 * <code>
  34 *
  35 * require_once(AK_LIB_DIR.'/AkDbSession.php');
  36 *
  37 * $AkDbSession = new AkDbSession();
  38 * $AkDbSession->sessionLife = AK_SESSION_EXPIRE;
  39 * session_set_save_handler (
  40 * array(&$AkDbSession, '_open'),
  41 * array(&$AkDbSession, '_close'),
  42 * array(&$AkDbSession, '_read'),
  43 * array(&$AkDbSession, '_write'),
  44 * array(&$AkDbSession, '_destroy'),
  45 * array(&$AkDbSession, '_gc')
  46 * );
  47 *
  48 * </code>
  49 *
  50 * @author Bermi Ferrer <bermi at akelos com>
  51 * @copyright Copyright (c) 2002-2005, Akelos Media, S.L. http://www.akelos.org
  52 * @license GNU Lesser General Public License <http://www.gnu.org/copyleft/lesser.html>
  53 * @since 0.1
  54 * @version $Revision 0.1 $
  55 */
  56 class AkDbSession extends AkObject
  57 {
  58     // {{{ properties
  59
  60
  61     // --- Public properties --- //
  62
  63
  64     /**
  65     * Secconds for the session to expire.
  66     *
  67     * @see setSessionLife
  68     * @access public
  69     * @var integer $sessionLife
  70     */
  71     var $sessionLife = AK_SESSION_EXPIRE;
  72
  73
  74     // --- Protected properties --- //
  75
  76
  77     /**
  78     * Database instance handler
  79     *
  80     * Stores a reference to an ADODB database instance.
  81     *
  82     * @access protected
  83     * @var object $_db
  84     */
  85     var $_db;
  86
  87     // }}}
  88
  89
  90     /**
  91     * Original session value for avoiding hitting the database in case nothing has changed
  92     *
  93     * @access private
  94     * @var string $_db
  95     */
  96     var $_original_sess_value = '';
  97
  98     // }}}
  99
 100
 101     // ------ CLASS METHODS ------ //
 102
 103
 104
 105     // ---- Setters ---- //
 106
 107
 108     // {{{ setSessionLife()
 109
 110     /**
 111     * $this->sessionLife setter
 112     *
 113     * Use this method to set $this->sessionLife value
 114     *
 115     * @access public
 116     * @see get$sessionLife
 117     * @param    integer    $sessionLife    Secconds for the session to expire.
 118     * @return bool Returns true if $this->sessionLife has been set
 119     * correctly.
 120     */
 121     function setSessionLife($sessionLife)
 122     {
 123         $this->sessionLife = $sessionLife;
 124
 125     }
 126
 127     // }}}
 128
 129
 130     // ---- Protected methods ---- //
 131
 132
 133     // {{{ _open()
 134
 135     /**
 136     * Session open handler
 137     *
 138     * @access protected
 139     * @return boolean
 140     */
 141     function _open()
 142     {
 143         $this->_db =& Ak::db();
 144         return true;
 145     }
 146
 147     // }}}
 148     // {{{ _close()
 149
 150     /**
 151     * Session close handler
 152     *
 153     * @access protected
 154     * @return boolean
 155     */
 156     function _close()
 157     {
 158         /**
 159         * @todo Get from cached vars last time garbage collection was made to avoid hitting db
 160         * on every request
 161         */
 162         $this->_gc();
 163         return true;
 164     }
 165
 166     // }}}
 167     // {{{ _read()
 168
 169     /**
 170     * Session read handler
 171     *
 172     * @access protected
 173     * @param    string    $id    Session Id
 174     * @return string
 175     */
 176     function _read($id)
 177     {
 178         $query_result = $this->_db->Execute("SELECT value FROM sessions WHERE id = ".$this->_db->qstr($id));
 179         if(!$query_result && AK_DEBUG){
 180             trigger_error($this->_db->ErrorMsg(), E_USER_NOTICE);
 181         }else{
 182             $this->_original_sess_value = (string)$query_result->fields[0];
 183             return $this->_original_sess_value;
 184         }
 185         return '';
 186     }
 187
 188     // }}}
 189     // {{{ _write()
 190
 191     /**
 192     * Session write handler
 193     *
 194     * @access protected
 195     * @param    string    $id
 196     * @param    string    $data
 197     * @return boolean
 198     */
 199     function _write($id, $data)
 200     {
 201         // We don't want to hit the db if nothing has changed
 202         if($this->_original_sess_value != $data){
 203             $ret = $this->_db->Replace('sessions', array('id'=>$this->_db->qstr($id),'expire'=>$this->_db->DBTimeStamp(time()),'value'=>$this->_db->qstr($data)), 'id');
 204             if($ret == 0){
 205                 return false;
 206             }else{
 207                 return true;
 208             }
 209         }else {
 210             return true;
 211         }
 212     }
 213
 214     // }}}
 215     // {{{ _destroy()
 216
 217     /**
 218     * Session destroy handler
 219     *
 220     * @access protected
 221     * @param    string    $id
 222     * @return boolean
 223     */
 224     function _destroy($id)
 225     {
 226         if(!$this->_db->Execute('DELETE FROM sessions WHERE id = '.$this->_db->qstr($id)) && AK_DEBUG){
 227             trigger_error($this->_db->ErrorMsg(), E_USER_NOTICE);
 228         }
 229         return (bool)@$this->_db->Affected_Rows();
 230     }
 231
 232     // }}}
 233     // {{{ _gc()
 234
 235     /**
 236     * Session garbage collection handler
 237     *
 238     * @access protected
 239     * @return boolean
 240     */
 241     function _gc()
 242     {
 243         if(!$this->_db->Execute('DELETE FROM sessions WHERE expire < '.$this->_db->DBTimeStamp(time()-$this->sessionLife)) && AK_DEBUG){
 244             trigger_error($this->_db->ErrorMsg(), E_USER_NOTICE);
 245         }
 246         return (bool)$this->_db->Affected_Rows();
 247     }
 248
 249     // }}}
 250
 251
 252 }
 253
 254 }// End of if(!defined('AK_DBSESSION_CLASS_INCLUDED')){
 255
 256 ?>