Zstd (compress/zstd)

Modern compression with excellent ratio-to-speed balance (RFC 8878). Zstandard consistently outperforms both Gzip and LZ4 in compression ratio while maintaining competitive decompression speed.

Usage

import { zstdCompress, zstdDecompress, zstdGetFrameContentSize } from "compress/zstd";

let data = "Zstandard in pure Vex!";
let ptr = data.as_ptr() as *void;
let len = data.len() as i64;

let outCap = len + len / 8 + 18;
let comp = alloc(outCap as u64);
let compLen = zstdCompress(ptr, len, comp, outCap);

let origSize = zstdGetFrameContentSize(comp, compLen);
let decomp = alloc(origSize as u64);
let decompLen = zstdDecompress(comp, compLen, decomp, origSize);

API

Function	Description
zstdCompress(src, srcLen, dst, dstCap): i64	Compress into Zstd frame
zstdDecompress(src, srcLen, dst, dstCap): i64	Decompress Zstd frame
zstdGetFrameContentSize(src, srcLen): i64	Read content size from frame header

Internal Architecture

File	Purpose
compress.vx	Frame compression with LZ77 matching
decompress.vx	Frame decompression
fse.vx	Finite State Entropy coding (tANS)
huffman.vx	Huffman tree decoding
bitreader.vx	Backward bit reader for entropy streams

The reference C implementation is ~20,000 lines. Vex achieves feature parity in ~1,060 lines — a 95% reduction.