how do I `download_byte_limit` with curb

The patron gem has a handy setting: https://github.com/toland/patron/commit/f168aab84c109066959110b6380311ab3d049464 It's useful when your application receives URLs to query from a regular user. So, is using Curl::Easy#on_progress callback is a correct and reliable way to protect against too large responses, gzip bombs and etc.?