A fully compatible implementation of LevelDB in Rust. (any incompatibility is a bug!)

The implementation is very close to the original; often, you can see the same algorithm translated 1:1, and class (struct) and method names are similar or the same.

NOTE: I do not endorse using this library for any data that you care about. I do care, however, about bug reports.

• User-facing methods exist: Read/Write/Delete; snapshots; iteration
• Compaction is supported, including manual ones.
• Fully synchronous: Efficiency gains by using non-atomic types, but writes may occasionally block during a compaction. In --release mode, an average compaction takes 0.2-0.5 seconds.
• Compatible with the original implementation. If it isn't (crash/read error/write error), it's a bug and needs to be fixed.
• Performance is decent; while not quite up to par with the original (we don't use multithreading, for example) it is very much usable.
• Safe: Many places use asserts though, so you may rarely see a crash -- in which case you should file a bug.

Some of the goals of this implementation are

• As few copies of data as possible; most of the time, slices of bytes (&[u8]) are used. Owned memory is represented as Vec<u8> (and then possibly borrowed as slice). Zero-copy is not always possible, though, and sometimes simplicity is favored.
• Correctness -- self-checking implementation, good test coverage, etc. Just like the original implementation.
• Clarity; commented code, clear structure (hopefully doing a better job than the original implementation).
• Coming close-ish to the original implementation; clarifying the translation of typical C++ constructs to Rust.