leveldb-rs

Goal: A fully compatible implementation of LevelDB in Rust.

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: Do not use this for production purposes unless you thoroughly evaluated it first, and are reasonably certain that no data loss occurs.

Status

• 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.
• Compatibility with the original: Compression is not implemented so far; this works as long as compression is disabled in the original.
• Performance is decent; while usually not par with the original, due to multi-threading in the original and language-inherent overhead (we are doing things the right way), it will be enough for most use cases.
• Safe: While using many shared pointers, the implementation is generally safe. Many places use asserts though, so you may see a crash -- in which case you should file a bug.

Goals

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).
• 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.