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Re: hpack static table question?

From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Tue, 3 Jun 2014 00:22:39 +0900
Message-ID: <CAPyZ6=L1K5irjt8JGZt-FtGrui7geiiTHGvXNhZBRUruhH8M-g@mail.gmail.com>
To: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Cc: Greg Wilkins <gregw@intalio.com>, HTTP Working Group <ietf-http-wg@w3.org>
On Tue, Jun 3, 2014 at 12:07 AM, Ilari Liusvaara <
ilari.liusvaara@elisanet.fi> wrote:

> On Mon, Jun 02, 2014 at 04:45:28PM +0200, Greg Wilkins wrote:
> > The hpack draft 7 says in 3.2.1 : "The referenced static entry is
> inserted
> > at the beginning of the header table".
> >
> > I can't understand why this copy of a static entry to the dynamic table
> is
> > needed?   Doesn't this mean that the static entry will now be known by
> two
> > indexes?     Why is this copy needed?
>
> AFAIK, to avoid needing having to keep state bits (2 per entry[1]) for the
> static table.
>
> Yeah, the static table is 61 entries, thus the amount of state needed would
> be just 16 bytes.
>
>
> [1] In set and emitted bits.
>
>
​Another reason is that we can clear reference set when ​setting
SETTINGS_HEADER_TABLE_SIZE to 0 if we static entry is copied int dynamic
header table when it is referenced.

Best regards,
Tatsuhiro Tsujikawa



>
> -Ilari
>
>
Received on Monday, 2 June 2014 15:23:26 UTC

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