RE: I ran across this while working on the spec.

I'm wondering if we want to be able to clear out all compression state. We currently have 59 entries in the static table, meaning 8 bytes to store whether they are in the reference set or not.

I we want this, I think #1 is too complex.

It means that sending an index (therefore adding a new entry to the reference set) may trigger an eviction.

We have several other solutions for this:
- #2
- 3 Adding the possibility of clearing the reference set inside a header block.
- 4 Having a special rule for a max header table of 0, stating that this clears all the compression state.


My preference is for 2 or 3.

Hervé.


> -----Original Message-----
> From: Fred Akalin [mailto:akalin@google.com]
> Sent: jeudi 17 octobre 2013 04:10
> To: Roberto Peon
> Cc: ietf-http-wg@w3.org Group
> Subject: Re: I ran across this while working on the spec.
> 
> (copying from issue)
> 
> #1 <https://github.com/http2/http2-spec/issues/1>  has the problem that it
> introduces an ambiguity in what to do when reducing the max size (clear out
> the reference set first?). But if we specify exactly what to do when reducing
> the max size, then that isn't that bad.
> 
> 
> 
> On Wed, Oct 16, 2013 at 5:37 PM, Roberto Peon <fenix@google.com> wrote:
> 
> 
>  https://github.com/http2/http2-spec/issues/281

> 
>  Setting the max header size to 0 does not clear out all encoder state.
> 
>  In particular, elements to the reference set that are pointing to static
> table elements are not cleared out.
> 
>  There are a couple of obvious ways of fixing this:
>  1) Include the space used in the reference set in the overhead (e.g.
> 2-bytes per reference)
>  2) explicit SETTING for clearing the compression state
> 
> 
>  I prefer #1.
>

Received on Thursday, 17 October 2013 14:35:14 UTC