private function _get_cache_file_name($request)
{
// iterate through the options associated with the request
foreach ($request['options'] as $key => $value) {
// ...and remove null or empty values
if (is_null($value) || $value == '') {
unset($request['options'][$key]);
}
}
// remove some entries associated with the request
// callback, arguments and the associated file handler (where it is the case) are not needed
$request = array_diff_key($request, array('callback' => '', 'arguments' => '', 'file_handler' => ''));
// return the path and name of the file name associated with the request
return rtrim($this->cache['path'], '/') . '/' . md5(serialize($request));
}