RE: Header Serialization Discussion

RUELLAN Herve <Herve.Ruellan@crf.canon.fr> Tue, 16 April 2013 16:04 UTC

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From: RUELLAN Herve <Herve.Ruellan@crf.canon.fr>
To: "Adrien W. de Croy" <adrien@qbik.com>, James M Snell <jasnell@gmail.com>
CC: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Thread-Topic: Header Serialization Discussion
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Date: Tue, 16 Apr 2013 15:56:50 +0000
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Subject: RE: Header Serialization Discussion
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I did some statistics on prefix sharing to find which header do most benefit from it.

==== Requests ====
:path                              :  96977
referer                            :  26060
cookie                             :  23081
:host                              :   5365
==== Responses ====
expires                            :  45442
last-modified                      :  44312
date                               :  42512
cache-control                      :  22096
via                                :  20106
content-length                     :   5603
set-cookie                         :   5337
server                             :   4019
age                                :   3845
content-type                       :   3675

For each header, the cumulated size of the shared prefixes is shown.

For responses, a large part of these headers can be optimized using a typed encoding. However, prefix sharing could still be useful for the remaining ones. For requests, none of the headers can be optimized with some typed encoding (except maybe the ":host" header).

Hervé.

> -----Original Message-----
> From: Adrien W. de Croy [mailto:adrien@qbik.com]
> Sent: mardi 16 avril 2013 01:44
> To: James M Snell; RUELLAN Herve
> Cc: ietf-http-wg@w3.org
> Subject: Re: Header Serialization Discussion
> 
> 
> 
> ------ Original Message ------
> From: "James M Snell" <jasnell@gmail.com>
> >On Mon, Apr 15, 2013 at 8:28 AM, RUELLAN Herve
> ><Herve.Ruellan@crf.canon.fr> wrote:
> >>
> >>[snip]
> >>>
> >>>    - The true utility of the common prefix length mechanism is
> >>>questionable.
> >>>  Aside from the potential security risks, I questioning just how
> >>>effective it's
> >>>  going to be in practice. (What header fields do we expect to
> >>>actually use it in
> >>>  practice?)
> >>
> >>  Common prefixes are very efficient for URLs: the paths often share
> >>some common part at their beginnings. They are also useful for other
> >>type of data such a date and integers, but these could be optimized
> >>using typed codecs.
> >>
> >
> >I generally prefer the typed codecs for dates and integers. I'm
> >struggling to see what, beyond URLs, the prefixes will be useful for,
> >really. I mean, I get the theory, I understand their use, but I'm just
> >not convinced how often it will be practical outside of the request
> >URI.
> 
> Referer as well
> 
> 
> 
> Adrien
> 
> >
> >
>