# Fastmurmur3 Murmur3 is a fast, non-cryptographic hash function. `fastmurmur3` is, in my testing, the fastest implementation of Murmur3. # Usage let bytes: &[u8] = b"hello world"; let x: u128 = fastmurmur3::hash(bytes); # Installation cargo install fastmurmur3 # Benchmarks ### Summary According to current benchmarks: - `fastmurmur3` is the fastest. - `xxh3_64` is 1.66x slower and only has a 64-bit value. - `xxh3_128` is 2.50x slower. - `fasthash` contains the next fastest murmur3 implementation, but is still 4.47x slower than `fastmurmur3`. ### Data ``` fastmurmur3 time: [3.0878 ns 3.1215 ns 3.1619 ns] xxhash_rust::xxh3_64 time: [5.1473 ns 5.1872 ns 5.2456 ns] xxhash_rust::xxh3_128 time: [7.8066 ns 7.8271 ns 7.8499 ns] fasthash time: [13.909 ns 13.960 ns 14.018 ns] murmur3c time: [14.529 ns 14.604 ns 14.684 ns] murmur3 time: [26.084 ns 26.163 ns 26.249 ns] twox_hash::Xxh3Hash64 time: [124.23 ns 126.46 ns 128.55 ns] twox_hash::Xxh3Hash128 time: [134.62 ns 136.75 ns 138.77 ns] sha1 time: [209.55 ns 211.71 ns 214.88 ns] ``` ### Benchmark Future Work - [ ] These benchmarks are run on a limited input set and with a limited seed set. These more extensive benchmarks need to happen before definitively making the claim that `fastmurmur3` is the fastest non-cryptographic hash function. - [ ] I'm not sure if these benchmarks are unfair to the reference C implementation because of linkage (i.e. rust function gets fully inlined, whereas C implementation stays as a separate fn call because of linking algorithm). - [ ] Besides speed, these benchmarks could also measure other hash properties like collision-resistance in comparison to other algorithms (`xxhash`, etc.). - [ ] It'd be nice to have pretty charts of the benchmarks. - [ ] I'd like to understand if there's steps I can take to make the benchmarks more reproducible (e.g. setting process priority, failing if it encounters memory contention, etc.) - [ ] I'd like to improve the benchmarking readout and abstract it into a better comparison tool. Right now, cargo bench and cargo criterion are built for tracking performance of the project over time. I'd like to have a better library for comparing performance within a benchmark group. # Correctness The tests for `fastmurmur3` perform fuzzing in comparison to the C implementation. # Contributing Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are **greatly appreciated**. If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again! 1. Fork the Project 2. Create your Feature Branch (`git checkout -b feature/AmazingFeature`) 3. Commit your Changes (`git commit -m 'Add some AmazingFeature'`) 4. Push to the Branch (`git push origin feature/AmazingFeature`) 5. Open a Pull Request