Re: [web-devel] http-enumerator : Any way to get the headers first?

Michael Snoyman wrote:

On Mon, May 16, 2011 at 11:23 AM, Erik de Castro Lopo wrote:

...

c) Modify the Network.Http.Enumerator.http function so that de-chunking/gunzipping is optional.

d) Expose the iterHeaders function that is internal to the http-enumerator package so that client code can grab the headers before deciding how to handle the body.

Are there any other options I haven't thought of yet?

From the options I have, I actually think d) makes the most sense, Would a patch exposing iterHeaders be accepted?

Short answer is that I'm fine exposing iterHeaders, as long as we put a big fat "advanced users only" comment on it. I agree with you that (b) seems like a bad idea. (a) is definitely possible, if a bit tricky, but it defeats the whole purpose of chunking and gzipping, so it probably shouldn't be considered.

I would guess that (c) is really the best option, though I'm guessing you shied away from it because it involved more substantial changes to http-enumerator.

I shied away from c) for two reasons: - I thought exposing iterHeaders would have other uses as well. - How do we know that we are at the end of the request body? With chunked/gzipped data (and no content-length header) the body decoder figures out where the end is. I'll have a play with c) and see how it behaves. My idea is to simply be to add a rawData :: Bool field to the Request data structure. If that element is True then no dechunking or gunzipping will occur. Once I've tried this relatively trivial change I will know for sure what the happens at the end of the body.

I wouldn't be surprised if we come up with more such cases in the future.

Indeed. Cheers, Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/