speed up relink script

[TK Soh]

On 3/19/07, Brendan Cully <brendan at kublai.com> wrote:
> If you want to speed it up, you might try searching from the back to
> the front (differences should show up faster that way), or perhaps
> forking off md5sum for the candidate lists and comparing by that
> (possibly hand-checking matches for md5 collisions). I can't convince
> myself that it's safe to assume that a match in the last chunk is
> sufficient.

Me neither. I don't like forking that much, but reading from the back
to front seem like a good idea, though it might be a little awkward to
implement. I'll look into it.

> You probably don't need to pass around file sizes - if the source and
> destination don't have the same size, you won't be comparing them
> anyway.

Ahh.. the st_size's should be the same. Thanks.