- From: James M Snell <jasnell@gmail.com>
- Date: Thu, 9 Aug 2012 18:45:28 -0700
- To: "Adrien W. de Croy" <adrien@qbik.com>
- Cc: Amos Jeffries <squid3@treenet.co.nz>, ietf-http-wg@w3.org, Mike Belshe <mike@belshe.com>
- Message-ID: <CABP7RbdNWSm_qWwnnKks3NtKwWrNk5Sy_Tj85HjunZV3hx6aKg@mail.gmail.com>
They're currently not forbidden but would be fairly pointless, so we may be safe. On Aug 9, 2012 5:09 PM, "Adrien W. de Croy" <adrien@qbik.com> wrote: > > do we even envisage sending entity headers on 1xx responses? > > I don't know if it's a good idea. > > in which case, we'd only get entity headers on the final response before > the data. > > Adrien > > > > ------ Original Message ------ > From: "James M Snell" <jasnell@gmail.com> > To: "Mike Belshe" <mike@belshe.com> > Cc: "Amos Jeffries" <squid3@treenet.co.nz>;"ietf-http-wg@w3.org" < > ietf-http-wg@w3.org> > Sent: 10/08/2012 10:54:37 a.m. > Subject: Re: Some general SPDY feedback / questions > > > On Aug 9, 2012 2:26 PM, "Mike Belshe" <mike@belshe.com> wrote: > > > > > [Snip] > > > > > > When you do this, it opens up a new set of things to define: > > - what happens if a header is superseded later? can you send the same > header twice? > > There is a definite trade off in complexity, that's for sure... but if we > need to support 1xx responses I don't see another way to do it without > increasing the complexity even further. > > Headers would essentially be single value, if a subsequent headers frame > repeats a previously seen header, the value for that header is replaced. If > the application has already processed that header, the application needs to > figure out how to handle the situation. > > > - when can a receiver know when headers are 'done'? If you sent one > set of cache-related headers, can you send further ones later? > > The headers are done once the first data frame is sent or the FIN is > received. > > For cache headers, it would be important to note that repeated headers > would replace the existing value, not add to the value, so subsequent cache > control headers would supersede any that came before. > > > > > I know these sound like edges, and even the spdy framer sort-of allows > header frames at any time... but at the app layer, it creates a lot of new > questions that http doesn't have today. this is why in SPDY we just said > "although the framing layer can do it, for HTTP's purposes, you (mostly) > can't". > > > > Understood, and the reasoning is sound, but there really doesn't appear to > be another simpler way of supporting provisional responses. There is an > increased burden on the developer to handle repeated headers properly but I > doubt that burden is much more than what developers are already accustomed > to. > > - James > > > Mike > > > > > > > > > >> > >> > >> Amos > >> > > > >
Received on Friday, 10 August 2012 01:45:58 UTC