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Re: Issue re. HTTP2 STREAM and HEADER block use same end bit polarity

From: Amos Jeffries <squid3@treenet.co.nz>
Date: Sun, 16 Jun 2013 16:45:27 +1200
Message-ID: <51BD42E7.8060907@treenet.co.nz>
To: ietf-http-wg@w3.org
 From an implementation point of view a default value of 0 for both 
flags is easiest of all to implement, with polarity of 1 being set for 
the exceptional cases.

The bulk of frames in a stream will *not* be the FINAL frame. Likewise 
the bulk of headers delivered will likely be small enough to *not* have 
a CONTINUES necessary.

So to me the existing polarity seems to be correct. I propose renaming 
the CONTINUES flag to "EXTEND" (extended headers present) or "LARGE" 
(large header set) or "MULTI" (multiple header blocks) or something 
else  avoiding the unfortunate wording overlap with the FINAL semantics 
description.

Amos

On 16/06/2013 12:49 p.m., Roberto Peon wrote:
> no objections here with the proposal.
>
>
> On Sat, Jun 15, 2013 at 5:15 PM, James M Snell <jasnell@gmail.com 
> <mailto:jasnell@gmail.com>> wrote:
>
>     And fwiw, I already had a note for this in my list of todos
>     following the interim.
>
>     On Jun 15, 2013 5:13 PM, "James M Snell" <jasnell@gmail.com
>     <mailto:jasnell@gmail.com>> wrote:
>
>         +1... consistency makes the most sense.
>
>         On Jun 15, 2013 5:06 PM, "William Chan (ι™ˆζ™Ίζ˜Œ)"
>         <willchan@chromium.org <mailto:willchan@chromium.org>> wrote:
>
>             I don't particularly care. I just want to point out that
>             the reason it "natural" to do it the way it's already
>             done, is FINAL and CONTINUES are the exceptional cases. So
>             to the degree that it's nicer to by default have no flags
>             set, the current approach is better. I don't have any
>             paint to waste on this bike shed though.
>
>             On Sat, Jun 15, 2013 at 4:57 PM, Mike Belshe
>             <mike@belshe.com <mailto:mike@belshe.com>> wrote:
>
>                 I agree on the consistency issue Dave presents.  I
>                 also like Dave's suggestion to use 1 to mean final
>                 everywhere.
>
>                 Mike
>
>                 process question:  is it valuable to reply in github?
>                  or is the list preferred?
>
>
>             Always the list. If you see much discussion on github,
>             yell at them to bring it to the list. And any
>             commits/issues/updates on github should reference the
>             rough consensus from the mailing list.
>
>
>
>
>                 On Sat, Jun 15, 2013 at 4:14 PM, David Morris
>                 <dwm@xpasc.com <mailto:dwm@xpasc.com>> wrote:
>
>
>
>                     This issue:
>
>                     https://github.com/http2/http2-spec/issues/129
>
>                     describes my concern that the polarity is reversed
>                     between STREAM FINAL
>                     and HEADER CONTINUES which are both flag bits used
>                     to manage continuation.
>
>                     I think this will introduce confusion to folks
>                     analyzing wire level bits
>                     as well as reading code.
>
>                     I do acknowledge the the current flag names match
>                     the sense of the
>                     polarity so the names probably should change.
>
>                     Dave Morris
>
>
>
>
Received on Sunday, 16 June 2013 04:46:01 UTC

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