Re: Straw Poll: Restore Header Table and Static Table Indices

The current mechanism is highly suboptimal when not using the headers in
the static table.

There has been no technical argument refuting this-- all arguments have
shown that the previous arrangement was approximately on par for
static-table heavy workloads in terms of compression efficiency.

We have no guarantee that users will always wish to use the arguments in
the static table.
We know that adding to the size of the static table decreases efficiency of
the compressor for any item that would not be in the static table.

No-one has shown that the new scheme is significantly better in terms of
CPU or memory.

There was no interop issue w.r.t. the previous text.

In fact, the previous text allowed for the static table to be changed
easily in future versions, with guaranteed detection of mismatch when new
elements have been appended to the static table by one implementation but
not the other. This is not true of the current version, which would require
a negotiation in order to figure any such things out, and would otherwise
result in corruption.


As currently specc'd we're half-assing the compression, and we already know
a better solution and have specc'd, implemented and demonstrated interop
with it.
-=R

On Sat, Oct 11, 2014 at 11:59 PM, Mark Nottingham <mnot@mnot.net> wrote:

> There doesn't seem to be support for making a change here; most people
> were against any change, and while there were a few other proposals made,
> they didn't get broad support. Since this isn't a security or interop
> issue, I'm inclined to close as WONTFIX.
>
> Does anybody have new information here, or can we move on?
>
> Cheers,
>
>
> On 7 Oct 2014, at 6:23 am, Mark Nottingham <mnot@mnot.net> wrote:
>
> > Thanks, Jeff.
> >
> > I see people have already started to respond to this.
> >
> > Everyone else, please do the same — if you think this needs more
> discussion, please do so, but I think we’re at a point where people can
> just state their preferences.
> >
> > Regards,
> >
> >
> > On 7 Oct 2014, at 2:02 am, Jeff Pinner <jpinner@twitter.com> wrote:
> >
> >> As request by Mark, I propose that the current HPACK draft be changed
> >> such that Sec. 2.3.3 Index Address Space reads,
> >>
> >> "Indices between 1 and the length of the dynamic table (inclusive)
> >> refer to elements in the dynamic table.
> >>
> >> Indices strictly greater than the length of the dynamic table refer to
> >> elements in the static table. The length of the dynamic table is
> >> subtracted from the index into the static table."
> >>
> >> with the associated diagram updated. This reverts the change made
> >> between draft -08 and -09 in the change log, "Exchanged header and
> >> static table positions."
> >>
> >
> > --
> > Mark Nottingham   http://www.mnot.net/
> >
> >
> >
> >
>
> --
> Mark Nottingham   https://www.mnot.net/
>
>
>