Re: [#153] PUSH_PROMISE headers

Martin Thomson <martin.thomson@gmail.com> Mon, 01 July 2013 20:04 UTC

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Date: Mon, 01 Jul 2013 13:01:48 -0700
Message-ID: <CABkgnnWPcPEij7P-DCvHOwNxSB8pqxRvWVwn==Aaxf1a0-3Dvg@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Mike Bishop <Michael.Bishop@microsoft.com>
Cc: Roberto Peon <grmocg@gmail.com>, James M Snell <jasnell@gmail.com>, HTTP Working Group <ietf-http-wg@w3.org>
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Subject: Re: [#153] PUSH_PROMISE headers
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On 1 July 2013 11:44, Mike Bishop <Michael.Bishop@microsoft.com> wrote:
> There are some wasted bytes if the server sends back the entire request
> headers, since the headers are supposed to be copied from the initial
> request and the client already knows what it sent.  Are we presuming that
> the server is sending back only the headers whose values it wants to
> override?  (If so, how does the server express that it wants to drop a
> header, override it to empty?)

I think that this is the bit that will need additional refinement.  As
this describes, the headers that are included in PUSH_PROMISE replace
headers (or add new ones) that are in the associated request.

That leads to some interesting questions with respect to compression.
Maybe the right way to do this is to have PUSH_PROMISE include ALL
headers from the associated request, and then use that associated
request as the reference from which compression builds.

Of course, that would be grossly premature, given how little we know
of usage patterns for push.