[jbooth]

It's pretty easy to throw together a variant using longs for position instead of unsigned ints, the rest of the code stays the same. Slightly more overhead in the file but as long as the items you're storing are bigger than a few bytes it's not a huge deal.

Anyways, it's useful for stuff where you want to ship out a big dictionary once a day or so and you need fast lookup but it doesn't have to be updated transactionally.