What is this?

This repo contains two things:

Elmo -- a prototype implementation of an embeddable Mongo-compatible database for use in mobile apps

LSM -- a log structured merge tree storage engine (similar in concept to leveldb)

Elmo supports a pluggable store engine API, currently with two implementations, one based on SQLite, and one based on the LSM library contained here.

LSM is not specific to Elmo or Mongo. At some point it needs to move out into its own repo as a general purpose library.

This stuff is not ready for production use. It has no documentation. Its file formats are still in flux. Its code doesn't always follow Rust conventions very well (yet).

For more info, see the blog entry at http://www.ericsink.com/entries/mobile_sync_for_mongo.html.

Is this open source?

Yes.

What's the license?

Apache License v2

What language is this written in?

Rust (nightly).

The initial prototype was written in F#. Some of that code is still hanging around here for reference purposes.

Why are you building this?

As part of our exploration of mobile sync solutions for Mongo.

For more info, see the blog entry mentioned near the top of this README.

Why is this called Elmo?

It stands for Embeddable Lite Mongo.

Why is the LSM library called LSM?

Because it doesn't have a name yet.