consistent hashing: in Perl, standards

[Brad Fitzpatrick]

Nice patch.  Applied & released!


On Wed, 25 Apr 2007, Larry Leszczynski wrote:

> On Wed, 25 Apr 2007, Brad Fitzpatrick wrote:
>
> > Back in August I posted some consistent hashing code.  I finally got
> > around to putting it into a Perl library recently:
> >
> >   http://search.cpan.org/~bradfitz/Set-ConsistentHash/
>
> I agree with Dustin that a specification and a reference
> implementation would be useful - I think in effect that is what Brad's
> code is (or could evolve into).
>
> FWIW, attached is a patch to Set::ConsistentHash that hides some
> implementation details and lets you change lookups from this:
>
>     $selected_target = $set->buckets->[your_hash_func($your_key) % 1024];
>
> to this:
>
>     $set->set_hash_func(\&your_hash_func);   // optional
>
>     $selected_target = $set->get_target($your_key);
>
>
> Also attached, a quick first cut at Cache::Memcached::ConsistentHash,
> which simply subclasses Set::ConsistentHash and sets the hash func to
> the one currently used in the Memcached client, i.e.:
>
>     crc32($_[0]) >> 16) & 0x7fff
>
>
> Larry