Re: [hybi] frame length encoding

[Pieter Hintjens <[e-mail]>]

On Sat, Aug 21, 2010 at 10:11 PM, John Tamplin <[e-mail]> wrote:

> Obviously, I don't know the details of your environment, but I suspect CPU
> speed will continue to increase faster than network speeds.

CPU core count increases but I think it's fair to say CPU speeds have
hit the top of the curve.  Thus we're constrained by the capacity of
one core to process the data off a network, while network capacity
continues to double every 18-24 months.

> I am a bit confused at your position -- in one sentence you suggest we
> should add another byte just in case we might use it, yet you are still
> worried about a single AND instruction?  Surely the cost of sending that
> byte is higher than one instruction?

The single AND instruction is not a problem.  Treating messages above
126 bytes as "long" means we miss the sweet spot.

> Regardless of the differences between #0 and #1, it already seemed clear
> that #1 was losing out to #2 or yet more complicated schemes, so I don't
> think option #0, which removes the one advantage compared to #3 or Shelby's
> proposal of preserving a reserved bit, will get any more backers than #1
> did.

Indeed, there are probably very few people in the open source world
concerned with efficiency at the level we are.  I've explained our
experience, and will leave it at that.

Thanks again for steering this issue, consensus is more important here
than the actual design, whatever that may be.

-
Pieter Hintjens
iMatix - www.imatix.com