Re: [Caml-list] IPv6 packet parsing

[rixed@happyleptic.org]

-[ Fri, Oct 18, 2013 at 12:59:55PM +0100, Anil Madhavapeddy ]----
> One feature I'd really like to see in Bitstring is support for Bigarray,
> since that avoids a copy into the OCaml heap and lets us do quite high
> performance parsing.  If I remember right, there was a patch on the
> Bitstring issue tracker, but it wasn't parameterised (so it's either
> Bistring+string or Bitstring+bigarray, which isn't ideal).

Pardon my lack of familiarity with bigarrays, but I can't see what's the
difference between copying packets from pcap ring buffer into a bigarray
or into a string. Or do you mean using Bigarray.map_file on the whole
raw ring buffer and handle it without pcap help?

In my own experience, what slows down bitstring the most is the small
size of its internal buffers (128 bytes, ie. too small for many packet).
This simple change
(https://github.com/rixed/bitstring/commit/59076eb4c5ee1c8ed8648fc559c62e108b9c5037)
got me approx 20% improvement.