public static function make_unique_filename($extention, $prefix = '', $original_filename = '', $retry_count = 3)
{
$name = self::make_filename($extention, $prefix, $original_filename);
$i = 0;
while (Model_File::check_name_exists($name)) {
$name = self::make_filename($extention, $prefix, $original_filename);
if ($i == $retry_count) {
return false;
}
$i++;
}
return $name;
}