Re: [hybi] Versioning is a anti-pattern

[Scott Ferguson <[e-mail]>]

John Tamplin wrote:
> On Fri, Sep 3, 2010 at 11:41 AM, Scott Ferguson <[e-mail] 
> <mailto:[e-mail]>> wrote:
>
>     I do have a minor, aesthetic suggestion for the framing to reorder
>     the bits so the reserved bits are contiguous.
>
>      * more(1)
>      * length(7)
>      * res(4)
>      * opcode(4)
>
>     It's not a substantive or important proposal, of course, but looks
>     a bit cleaner than splitting the reserved bits.
>
>
> I dislike having the bits of the length separated from each other 
> (since the 16/63-bit case it will come after the opcode).  In 
> particular, it makes it hard to write ABNF which is clear.

There's a value in putting more and length together since they're 
related. That would help debugging because a fragment would be easily 
recognizable as %xFE or %xFF instead of varying based on the reserved 
bits as the current frame encoding requires. For short packets, having 
the high bit clear will make the length easier to scan (assuming it's a 
non-fragment) than scanning would be if the high bit varies for 
unrelated extension reasons.

   * res(4)
   * opcode(4)
   * more(1)
   * length(7)

It's a matter of taste, really. Having the reserved split in two also 
makes the frame header look more complicated because it implies that 
RES1 and RES2 are reserved for different purposes rather than just being 
generic reserved bits.

But it really doesn't matter much, so I'll just leave the point out 
there and not argue for it further.

-- Scott

>
> -- 
> John A. Tamplin
> Software Engineer (GWT), Google