This is a simple database to convert 64-bit key and values into a fast readonly lookup file. I needed it as a way to quickly find hash values and a related file ID. With no cache, it requires at most 3 seeks for a lookup. 

Only tested on 64-bit platforms. Files can be mmap'd or read as a stream. Doesn't currently support merging files. Uses delta compression inside each page. From one test app, each 128-bit record was taking about 2.3 bytes. The closer the clustering of values, the better the compression.

I wrote my own because I couldn't find anything that met my overhead requirements. Linux support should not require many changes.

I'll add some samples and more comments soon.

Source is released under public domain. But if you find it useful, I'd love to hear about it (mgg@giagnocavo.net).