On Fri, Apr 06, 2007 at 12:08:17PM +1000, Graham Dumpleton wrote: | On 03/04/07, Clark C. Evans <[EMAIL PROTECTED]> wrote: | >On Fri, Mar 30, 2007 at 11:10:17AM +1000, Graham Dumpleton wrote: | >| One other issue if aiming at supporting chunked encoding for a request, | >| is how (if one even can) make available the trailing headers if present | >| after the final null data block. Personally I am not sure this one is | >| worth the trouble and may be quite hard to even implement with some web | >| servers as they don't even provide them as a separate set of headers but | >| simply merge them on top of the main request headers. | > | >In my particular application it'd be quite helpful if I could return | >Chunked-Body responses (especially ones with additional trailing | >headers). Since WSGI rules the use of transfer encodings, then it should | >have a mechanism to request this sort of behavior aka, yield a "flush" | >object that has optional trailing headers that should be included in the | >chunk that is returned. | | Do you know of any actual web servers that provide a facility for | sending trailers after the final null chunk in a response? Apache for | one doesn't provide a way of doing this
I'm starting to add support for 14.46 "Warning" headers [1] to my server application and custom client. Often times a warning might happen *after* the 200 has been sent; buffering isn't an option unfortunately. So, I need to find a way to send this additional information to the client. Most headers are kinda senseless as trailing headers, but this one is particularly useful. [1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.46 | Note the comment that step 2, sending of trailers doesn't yet exist. Sounds like Apache isn't a fully-compliant webserver ;) | So even if WSGI had a way of supplying trailers, I doubt there would | be many WSGI adapters for web servers that could actually implement | it. This doesn't mean our API shouldn't support it. It's a valid need and when I get time, I'd like to find a way to update paste's httpserver to support this sort of thing. | FWIW, in mod_wsgi I have now added a directive which allows one to | enable within a specific context that chunked transfer encoding should | be used for a response when a HTTP/1.1 client is being used. That's great ;) | At this stage is probably better than nothing given that WSGI doesn't | provide a way of enabling it. In your implementation, how would I indicate where the chunk boundaries should be? Or is this just a fixed size thing? Best, Clark _______________________________________________ Web-SIG mailing list Web-SIG@python.org Web SIG: http://www.python.org/sigs/web-sig Unsubscribe: http://mail.python.org/mailman/options/web-sig/archive%40mail-archive.com