Putting it all together - PHP

On the last few pages, we've talked about a bunch of little pieces that make up the sessions class.  I thought I would take a minute and give you the complete class in one shot.

class SessionManager {

   var $life_time;

   function SessionManager() {

      // Read the maxlifetime setting from PHP
      $this->life_time = get_cfg_var("session.gc_maxlifetime");

      // Register this object as the session handler
      session_set_save_handler( 
        array( &$this, "open" ), 
        array( &$this, "close" ),
        array( &$this, "read" ),
        array( &$this, "write"),
        array( &$this, "destroy"),
        array( &$this, "gc" )
      );

   }

   function open( $save_path, $session_name ) {

      global $sess_save_path;

      $sess_save_path = $save_path;

      // Don't need to do anything. Just return TRUE.

      return true;

   }

   function close() {

      return true;

   }

   function read( $id ) {

      // Set empty result
      $data = '';

      // Fetch session data from the selected database

      $time = time();

      $newid = mysql_real_escape_string($id);
      $sql = "SELECT `session_data` FROM `sessions` WHERE
`session_id` = '$newid' AND `expires` > $time";

      $rs = db_query($sql);                           
      $a = db_num_rows($rs);

      if($a > 0) {
        $row = db_fetch_assoc($rs);
        $data = $row['session_data'];

      }

      return $data;

   }

   function write( $id, $data ) {

      // Build query                
      $time = time() + $this->life_time;

      $newid = mysql_real_escape_string($id);
      $newdata = mysql_real_escape_string($data);

      $sql = "REPLACE `sessions`
(`session_id`,`session_data`,`expires`) VALUES('$newid',
'$newdata', $time)";

      $rs = db_query($sql);

      return TRUE;

   }

   function destroy( $id ) {

      // Build query
      $newid = mysql_real_escape_string($id);
      $sql = "DELETE FROM `sessions` WHERE `session_id` =
'$newid'";

      db_query($sql);

      return TRUE;

   }

   function gc() {

      // Garbage Collection

      // Build DELETE query.  Delete all records who have passed
the expiration time
      $sql = 'DELETE FROM `sessions` WHERE `expires` <
UNIX_TIMESTAMP();';

      db_query($sql);

      // Always return TRUE
      return true;

   }

}