public function add_data($filepath, $data = NULL)
{
if (is_array($filepath)) {
foreach ($filepath as $path => $data) {
$file_data = $this->_get_mod_time($path);
$this->_add_data($path, $data, $file_data['file_mtime'], $file_data['file_mdate']);
}
} else {
$file_data = $this->_get_mod_time($filepath);
$this->_add_data($filepath, $data, $file_data['file_mtime'], $file_data['file_mdate']);
}
}