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

[RUELLAN Herve <[e-mail]>]

> -----Original Message-----
> From: Willy Tarreau [mailto:[e-mail]]
> Sent: mercredi 15 octobre 2014 22:16
> To: Amos Jeffries
> Cc: [e-mail]
> Subject: Re: Straw Poll: Restore Header Table and Static Table Indices
> 
> On Wed, Oct 15, 2014 at 06:20:00PM +1300, Amos Jeffries wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > On 15/10/2014 6:11 p.m., Adrian Cole wrote:
> > >> If an argument can be made that 2 byte encodings are still too
> > >> large for dynamic headers, then instead of flipping back let's
> > >> investigate how the 1 byte slots can be shared between static and
> > >> dynamic.
> > > FWIW, I'm happy to implement an alternate approach, if one comes
> > > out. Thanks, Greg.
> > >
> >
> > Alternative approach has already been proposed. That the first bit of
> > the index is used as a flag to indicate static or dynamic table for
> > the remaning 7+ bits.
> >
> > That not only puts both on an even bias, but expands the range of
> > values getting 1-byte encodings in either table and removes the need
> > for the math complexity people are disliking.
> >
> > 1 stone, 3 birds.
> 
> I totally agree with this except that I don't see where you take that
> spare bit from, that's what initially led me to rethink the encoding.
> So if you konw where to find one bit, +1 for me obviously!

Everywhere where there's an index into the static/dynamic table, reduce the index size by 1 bit and use this bit as a flag to find which table is used.

Hervé.

> > (The paranoid in me can only think that it is being repeatedly
> > rejected despite evidence of its usefulness because of who proposed it.)
> 
> No need to be paranoid here, the most common reason is that it's hard to
> explain our thoughts and most of the time it ends up with each other
> understanding something different and either useless or scary. Noone's
> to blame for this, human languages are not appropriate for discussing
> bits and bytes.
> 
> Thanks,
> Willy
>