alpm-compress

A small library that provides streaming compression and decompression for multiple algorithms used in the ALPM ecosystem:

bzip2 (.bz2)
gzip (.gz)
xz (.xz)
zstd (.zst)

It offers a unified encoder/decoder API with configurable compression levels and, for zstd, optional multithreading.

Documentation

https://alpm.archlinux.page/rustdoc/alpm_compress/ for development version of the crate
https://docs.rs/alpm-compress/latest/alpm_compress/ for released versions of the crate

Examples

Compressing

use std::{fs::File, io::Write};

use alpm_compress::compression::{
    CompressionEncoder, 
    CompressionSettings, 
    ZstdThreads, 
    ZstdCompressionLevel
};
use tempfile::tempfile;

fn main() -> testresult::TestResult {
// Create an encoder that writes zstd-compressed data to a file.
let file = tempfile()?;
let settings = CompressionSettings::Zstd {
    compression_level: ZstdCompressionLevel::default(),
    threads: ZstdThreads::default(),
};

let mut encoder = CompressionEncoder::new(file, &settings)?;
encoder.write_all(b"alpm-compress makes compression easy")?;
let _file = encoder.finish()?; // retrieve the inner File when done
Ok(())
}

Compression settings default to zstd compression, but you can select other algorithms and levels:

use alpm_compress::compression::{
    CompressionSettings,
    Bzip2CompressionLevel, 
    GzipCompressionLevel, 
    XzCompressionLevel, 
    ZstdCompressionLevel, 
    ZstdThreads,
};

fn main() {
// Bzip compression
let bzip2 = CompressionSettings::Bzip2 { compression_level: Bzip2CompressionLevel::default() };
// Gzip compression
let gzip = CompressionSettings::Gzip { compression_level: GzipCompressionLevel::default() };
// Xz compression
let xz = CompressionSettings::Xz { compression_level: XzCompressionLevel::default() };
// Zstd compression
let zstd = CompressionSettings::Zstd { compression_level: ZstdCompressionLevel::default(), threads: ZstdThreads::default() };
}

Decompressing

use std::{fs::File, io::Read};

use alpm_compress::decompression::{DecompressionSettings, CompressionDecoder};
use tempfile::tempfile;

fn main() -> testresult::TestResult {
// Create a temporary file.
let mut file = tempfile()?;

// [..] Add zstd compressed content to the temporary file.
// Create an encoder that writes zstd-compressed data to a file.
use alpm_compress::compression::{CompressionEncoder, CompressionSettings, ZstdThreads, ZstdCompressionLevel};
use std::io::{Write, Seek};

let settings = CompressionSettings::Zstd {
    compression_level: ZstdCompressionLevel::default(),
    threads: ZstdThreads::default(),
};
let mut encoder = CompressionEncoder::new(file.try_clone()?, &settings)?;
encoder.write_all(b"alpm-compress makes compression easy")?;
encoder.flush()?;
encoder.finish()?;
file.rewind()?;

// Decompress a zstd-compressed file
let mut decoder = CompressionDecoder::new(file, DecompressionSettings::Zstd)?;

let mut buf = Vec::new();
decoder.read_to_end(&mut buf)?;
assert_eq!(buf, b"alpm-compress makes compression easy");
Ok(())
}

Contributing

Please refer to the contribution guidelines to learn how to contribute to this project.

License

This project can be used under the terms of the Apache-2.0 or MIT. Contributions to this project, unless noted otherwise, are automatically licensed under the terms of both of those licenses.

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