Added ChronicleMap persistence as an alternative to SQLite

[akumaburn]

I did recently add ChronicleMap (https://github.com/OpenHFT/Chronicle-Map) as a store to CQEngine and tested it successfully. It is license compatible with this project using the same type - Apache 2.0 license: https://github.com/OpenHFT/Chronicle-Map/blob/ea/LICENSE

Usage is like:

ChroniclePersistence<Community, String> diskPersistence = new ChroniclePersistence<>((SimpleAttribute<Community, String>) GUID_ATTRIB, new File("persist.dat"),String.class,Community.class,UUID.randomUUID().toString().length()+1,64 * 1024,1000000);

ConcurrentIndexedCollection<Community> communities = new ConcurrentIndexedCollection<>(diskPersistence);

[npgall]

This is very interesting, and something I would be interested in merging.

I am hoping soon to carve out some time to take a closer look.

[jeansossmeier]

@akumaburn This is cool, are you using this sucessfully?
Have you done any benchmarking?

Another performance improvement that could be done is instead of Protostuff, you could use Apache Fury, which is crazy fast.
https://github.com/apache/fury