bjitcask

A Clojure library that provides a high performance on-disk key-value store. Every get and put operation is guaranteed to trigger at most a single disk IO, so that the latency of operations is deterministic. This is a binary-compatibly implementation of Bitcask, which lives here: https://github.com/basho/bitcask and is described in the paper here: https://github.com/basho/bitcask/blob/develop/doc/bitcask-intro.pdf?raw=true

Besides get and put, bjitcask supports alter, which offers a limited form of transactions: you can atomically read as many keys as you want, but you can only atomically write a single key in the transaction.

Usage

bjitcask's public API can be found in the namespace bjitcask.

• bjitcask/open creates or opens a bjitcask at the given location
• bjitcask/close closes a bjitcask gracefully
• bjitcask/get reads a value from the bjitcask
• bjitcask/put writes a value to the bjitcask
• bjitcask/alter allows for multi-key read, single-key write transactions
• bjitcask/delete deletes the given key

Caveats

bjitcask can open a lot of files. Maybe you need more file descriptors? Try:

ulimit -n 10000

Gotchas

bjitcask currently doesn't release memory used to store keys when they're deleted.

License

Copyright © 2013 Aysylu and David Greenberg

Distributed under the Eclipse Public License, the same as Clojure.