Need a good .

I'm working on a pljava module. In it, I'd like to cache some allocated
structures (allocated using TopMemoryContext) using a string as the key. I
need a hash or binary-search table with dynamic size where I can store
arbitrary structures and then find them using strings. Typical size is less
than 100 entries and performance will be an issue. I'm sure something like
this exists in postgres but I haven't been able to find it. Please point me
in the right direction.

Thanks,

Thomas Hallgren