RE: Header Compression

RUELLAN Herve <Herve.Ruellan@crf.canon.fr> Mon, 17 June 2013 16:36 UTC

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From: RUELLAN Herve <Herve.Ruellan@crf.canon.fr>
To: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
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Thread-Topic: Header Compression
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Date: Mon, 17 Jun 2013 16:35:42 +0000
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Subject: RE: Header Compression
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Hi,

This is not a silly question: I updated the example to quickly and forgot to take into account the diff encoding of header sets. I will correct it in a future version.

Thanks for noticing this.

Hervé.
________________________________
From: Tatsuhiro Tsujikawa [tatsuhiro.t@gmail.com]
Sent: Friday, June 07, 2013 17:32
To: RUELLAN Herve
Cc: ietf-http-wg@w3.org
Subject: Re: Header Compression

Hi,


On Thu, Jun 6, 2013 at 4:17 AM, RUELLAN Herve <Herve.Ruellan@crf.canon.fr<mailto:Herve.Ruellan@crf.canon.fr>> wrote:
Roberto and I have been discussing for some time and we have created a joint proposal for Header Compression.

The resulting spec is available at:
https://github.com/http2/compression-spec

The main features of this proposal are:
- One single table for indexing headers as (name, value) pairs.
- HeaderDiff-based serialization (indexed header, literal header with either no indexing, addition indexing, or replacement indexing).
- Delta2-based diff between two successive header sets.
- Possibility of bounding table size.
- Least recently written eviction strategy when an insertion cause table size limit to be reached.


We will present it in details at the next interim meeting. Until then, all questions and comments are welcome.

I have a question about "reference set of headers" in section 3.3. Differential Coding.
It seems that reference set of headers are only referred in this section and I failed to see how it works.
I may be wrong but I don't see it in Appendix B. Example. It only refers to the update to the header table.
Is the reference set of headers equal to header table? It seems it is not.
Could you add each state of "reference set of headers" and its working set in the example so that the reader
can understand how it works? Sorry if this is the silly question, but it might help the reader like me.

Best regards,

Tatsuhiro Tsujikawa