<h1 align="center">
<img width="99" alt="Rust logo" src="https://raw.githubusercontent.com/jamesgober/rust-collection/72baabd71f00e14aa9184efcb16fa3deddda3a0a/assets/rust-logo.svg">
<br>
<b>compress-lib</b>
<br>
<sub><sup>DEFLATE, ZLIB, GZIP</sup></sub>
</h1>
<div align="center">
<a href="https://crates.io/crates/compress-lib"><img alt="Crates.io" src="https://img.shields.io/crates/v/compress-lib"></a>
<a href="https://crates.io/crates/compress-lib"><img alt="Downloads" src="https://img.shields.io/crates/d/compress-lib?color=%230099ff"></a>
<a href="https://docs.rs/compress-lib"><img alt="docs.rs" src="https://img.shields.io/docsrs/compress-lib"></a>
<a href="https://github.com/jamesgober/compress-lib/actions"><img alt="CI" src="https://github.com/jamesgober/compress-lib/actions/workflows/ci.yml/badge.svg"></a>
<a href="https://github.com/rust-lang/rfcs/blob/master/text/2495-min-rust-version.md"><img alt="MSRV" src="https://img.shields.io/badge/MSRV-1.85%2B-blue"></a>
</div>
<br>
<div align="left">
<p>
<strong>compress-lib</strong> compresses and decompresses the formats the web runs on: raw DEFLATE (RFC 1951), zlib (RFC 1950), and gzip (RFC 1952), with the per-message rules of WebSocket permessage-deflate (RFC 7692). One plain call covers the common case; a streaming engine underneath covers everything else.
</p>
<p>
The engine is sans-IO: you push input and pull output through buffers you own, and it never touches a socket or a file. Memory is fixed when an engine is built and never grows with input. Every decoder enforces an absolute output cap, and optionally a ratio cap, while it decodes, so a decompression bomb costs at most the cap. There is no <code>unsafe</code> code and no third-party runtime dependency.
</p>
<br>
<hr>
<p>
<strong>MSRV is 1.85+</strong> (Rust 2024 edition). <code>unsafe</code> is forbidden. <code>no_std</code> with <code>alloc</code> when the default <code>std</code> feature is off.
</p>
<blockquote>
<strong>Status: <code>0.2.0</code>, design lock.</strong> The complete planned API is in <a href="./docs/API.md"><code>docs/API.md</code></a>, each item with its version. CRC-32, Adler-32, the error type, limits, and levels ship now; the raw DEFLATE inflater arrives in <code>0.3</code>, the deflater and the RFC 7692 helpers in <code>0.4</code>, zlib and gzip framing in <code>0.5</code>. Design: <a href="./dev/PLAN.md"><code>dev/PLAN.md</code></a>; schedule: <a href="./dev/ROADMAP.md"><code>dev/ROADMAP.md</code></a>.
</blockquote>
</div>
<hr>
<br>
## Scope
Raw DEFLATE inflate and deflate with window bits 8 to 15 and levels 0 to 9; sync, full, and finish flushes; zlib and gzip framing with checksums always verified; preset dictionaries; per-message compression for WebSocket servers and clients (context takeover on or off); CRC-32 and Adler-32; `std::io` adapters. Brotli follows after 1.0. It does not negotiate HTTP or WebSocket headers (http-net and ws-net do) and it does not read archives.
## Quick start
```toml
[dependencies]
compress = { package = "compress-lib", version = "0.2" }
```
Available now:
```rust
let crc = compress::checksum::crc32(data); // gzip's checksum
let adler = compress::checksum::adler32(data); // zlib's checksum
```
Planned (0.3 to 0.5), the shape every codec follows:
```rust
let packed = compress::gzip::compress(body); // Vec<u8>, level 6
let body = compress::gzip::decompress(&packed)?; // capped at 64 MiB by default
```
The complete planned API, with the version each item arrives in, is in [`docs/API.md`](./docs/API.md).
<hr>
<br>
## Contributing
See <a href="./dev/DIRECTIVES.md"><code>dev/DIRECTIVES.md</code></a> for engineering standards and the definition of done. Before a PR: `cargo fmt --all`, `cargo clippy --all-targets --all-features -- -D warnings`, and `cargo test --all-features` must be clean.
<br>
<div id="license">
<h2>License</h2>
<p>Licensed under either of</p>
<ul>
<li><b>Apache License, Version 2.0</b>: <a href="./LICENSE-APACHE">LICENSE-APACHE</a></li>
<li><b>MIT License</b>: <a href="./LICENSE-MIT">LICENSE-MIT</a></li>
</ul>
<p>at your option.</p>
</div>
<div align="center">
<h2></h2>
<sup>COPYRIGHT <small>©</small> 2026 <strong>James Gober.</strong></sup>
</div>