lz4_flex

Fastest LZ4 implementation in Rust. Originally based on redox-os' lz4 compression, but now a complete rewrite. The results in the table are from a benchmark in this project (66Kb JSON).

Features

• Very good logo
• LZ4 Block format
• High performance
• 0,5s clean release build time
• Feature flags to configure safe/unsafe code usage
• no-std support (thanks @coolreader18)
• 32-bit support

Usage:

Compression and decompression uses no usafe via the default feature flags "safe-encode" and "safe-decode". If you need more performance you can disable them (e.g. with no-default-features).

Safe:

lz4_flex = { version = "0.7.0" }

Performance:

lz4_flex = { version = "0.7.0", default-features = false }

use lz4_flex::{compress_prepend_size, decompress_size_prepended};

fn main(){
    let input: &[u8] = b"Hello people, what's up?";
    let compressed = compress_prepend_size(input);
    let uncompressed = decompress_size_prepended(&compressed).unwrap();
    assert_eq!(input, uncompressed);
}

Benchmarks

The benchmark is run with criterion, the test files are in the benches folder.

Currently 3 implementations are compared, this one, the redox-version, lz-fear and the c++ version via rust bindings. The lz4-flex version is tested with the feature flags safe-decode and safe-encode switched on and off.

• lz4_redox_rust: https://crates.io/crates/lz4-compress
• lz4_cpp: https://crates.io/crates/lz4
• lz-fear: https://github.com/main--/rust-lz-fear

Results v0.4.1 10-12-2020 (safe-decode and safe-encode off)

cargo bench --no-default-features

Executed on Core i7-6700 Win10 WSL.

Results v0.4 04-12-2020 (safe-decode and safe-encode on)

cargo bench

Executed on Core i7-6700 Win10 WSL.

Miri

Miri can be used to find issues related to incorrect unsafe usage:

MIRIFLAGS="-Zmiri-disable-isolation -Zmiri-disable-stacked-borrows" cargo miri test --no-default-features

Fuzzer

This fuzz target fuzzes, and asserts compression and decompression returns the original input. cargo fuzz run fuzz_roundtrip

This fuzz target fuzzes, and asserts compression with cpp and decompression returns the original input. cargo fuzz run fuzz_roundtrip_cpp_compress

TODO

• Frame format
• High compression
• Dictionary Compression