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) with the block format.
AMD Ryzen 7 5800H, rustc 1.57.0-nightly (5ecc8ad84 2021-09-19), Linux Mint.
| Compressor | Compression | Decompression | Ratio | |----------------------|-------------|---------------|---------------| | lz4flex unsafe | 1897 MiB/s | 7123 MiB/s | 0.2289 | | lz4flex unsafe w. checkeddecode | 1897 MiB/s | 6637 MiB/s | 0.2289 | | lz4flex safe | 1591 MiB/s | 5163 MiB/s | 0.2289 | | lzzz (lz4 1.9.3) | 2235 MiB/s | 7001 MiB/s | 0.2283 | | lz4_fear | 886 MiB/s | 1359 MiB/s | 0.2283 | | snap | 1886 MiB/s | 1649 MiB/s | 0.2242 |
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 = "0.9.3" }
Performance:
lz4_flex = { version = "0.9.3", default-features = false }
Warning: If you don't trust your input and your are using the Block format, use checked-decode in order to avoid out of bounds access. When using the Frame format make sure to enable checksums.
lz4_flex = { version = "0.9.3", default-features = false, features = ["checked-decode"] }
```rust use lz4flex::{compressprependsize, decompresssize_prepended};
fn main(){ let input: &[u8] = b"Hello people, what's up?"; let compressed = compressprependsize(input); let uncompressed = decompresssizeprepended(&compressed).unwrap(); assert_eq!(input, uncompressed); } ```
no_std support is currently only for the block format, since the frame format uses std::io::Write, which is not available in core.
The benchmark is run with criterion, the test files are in the benches folder.
Currently 4 implementations are compared, this one, lz-fear and the c++ version via rust bindings and snappy. The lz4-flex version is tested with the feature flags safe-decode and safe-encode switched on and off.
cargo bench --no-default-features
Executed on Core i7-6700 Linux Mint.
cargo bench
Executed on Core i7-6700 Linux Mint.
Miri can be used to find issues related to incorrect unsafe usage:
MIRIFLAGS="-Zmiri-disable-isolation -Zmiri-disable-stacked-borrows" cargo +nightly miri test --no-default-features --features frame
This fuzz target generates corrupted data for the decompressor. Make sure to switch to the checked_decode version in fuzz/Cargo.toml before testing this.
cargo +nightly fuzz run fuzz_decomp_corrupt_block and cargo +nightly fuzz run fuzz_decomp_corrupt_frame
This fuzz target asserts that a compression and decompression rountrip returns the original input.
cargo +nightly fuzz run fuzz_roundtrip and cargo +nightly fuzz run fuzz_roundtrip_frame
This fuzz target asserts compression with cpp and decompression with lz4_flex returns the original input.
cargo +nightly fuzz run fuzz_roundtrip_cpp_compress