mopenzl

OpenZL compression and decompression in safe Rust.

• Byte-identical encoder. For the same input and global parameters, frames are exactly those of OpenZL v0.3.0's ZL_CCtx_compress with its default graph, or of its serial segmenter: format versions 21 to 27, levels -131072..=22, content and compressed checksums.
• Decoder for frames built from the default graph's codecs (stored and Zstandard chunks), with both checksums verified, single or concatenated frames, input and output limits, and explicit errors for codecs not ported yet.
• No unsafe. The checksum kernel uses fearless_simd with the instruction set detected once per codec; every backend writes the same bytes. Zstandard coding comes from mzstd, byte-identical to the zstd 1.5.7 OpenZL vendors.
• One feature per codec, all on by default (zstd today).
• Sans-I/O sessions for both directions, plus std::io adapters, and no_std + alloc support.

use mopenzl::{Compressor, Decompressor, EncoderConfig, Level};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut encoder = Compressor::new(EncoderConfig::from(Level::try_from(6)?))?;
    let frame = encoder.compress(b"format-aware compression")?;
    assert_eq!(Decompressor::default().decompress(&frame)?, b"format-aware compression");
    Ok(())
}

Status

This is the first phase of a port of the OpenZL framework: the serial compression path and the universal decoder's frame, chunk and stream-graph machinery. Other OpenZL codecs (entropy coders, field LZ, transforms), typed and multiple inputs, custom graphs, training and dictionaries are not ported yet; frames using them report DecodeError::Unsupported. See architecture for the mechanics and known gaps and the comparison for performance against the C library.

License

MIT OR Apache-2.0. Derived from OpenZL (BSD); see NOTICE.