compress

One-shot compression codecs for the aoughwl stack — gzip, Brotli, and Zstandard — over the system libraries. Protocol- agnostic string → string: no streaming state, no HTTP assumptions.

import compress

let gz = gzipCompress("...")          # Content-Encoding: gzip
let back = gzipDecompress(gz)
let br = brotliCompress("...")        # Content-Encoding: br
let zs = zstdCompress("...")          # Content-Encoding: zstd

What it does

Codec	Functions	Library
gzip / zlib	gzipCompress / gzipDecompress	libz.so.1
Brotli	brotliCompress / brotliDecompress	libbrotlienc / libbrotlidec
Zstandard	zstdCompress / zstdDecompress	libzstd.so.1

Each is a single call over an in-memory string. Decompressors are bounded by a maxSize argument. "" signals an error (bad input, library failure).

Why its own repo

The codecs are general-purpose: http layers Content-Encoding negotiation (pickEncoding / encodeFor) on top for HTTP, but a WebSocket (permessage-deflate), an on-disk blob store, or any binary protocol can depend on just this package without pulling in HTTP.

Design notes

• The zlib z_stream struct is hand-laid to the LP64 C ABI (no zlib headers needed); gzip uses window bits 31 (deflate) / 47 (auto-detect inflate).
• Brotli and Zstd use their one-shot APIs (BrotliEncoderCompress, ZSTD_compress), sized via BrotliEncoderMaxCompressedSize / ZSTD_compressBound.

Testing

nimony c -r --path:. tests/tcodecs.nim

Round-trips a compressible sample through all three codecs (verifying each shrinks it and restores it byte-for-byte; gzip additionally checks the 1f 8b magic).

Requirements

Nimony; libz, libbrotlienc/libbrotlidec, libzstd (all standard on Linux).

License

MIT.