dart_lz4 #

Pure Dart implementation of LZ4 (block + frame) and LZ4HC, including streaming frame decode.

Repository: https://github.com/jxoesneon/dart_lz4

Status #

This package is under active development.

Implemented:

• LZ4 block encode/decode
• LZ4 frame encode/decode
• Streaming frame decode (StreamTransformer)
• LZ4HC block compression

Goals #

• Pure Dart (no FFI)
• Web-safe core (no dart:io in library code)
• Strict, bounds-safe decoding with deterministic errors
• Streaming-friendly APIs with output limits
• Compatibility with LZ4 frame format (current) and best-effort legacy frame decode

Roadmap (high level) #

• xxHash32 (streaming) with VM + dart2js parity
• LZ4 block decode/encode
• LZ4 frame decode/encode
• Streaming APIs
• LZ4HC

Usage #

Block #

Block decompression requires the decompressed size.

import 'dart:typed_data';
import 'package:dart_lz4/dart_lz4.dart';

final src = Uint8List.fromList('hello'.codeUnits);
final compressed = lz4Compress(src);
final decoded = lz4Decompress(compressed, decompressedSize: src.length);

LZ4HC #

final compressed = lz4Compress(src, level: Lz4CompressionLevel.hc);

Frame #

final frame = lz4FrameEncode(src);
final decoded = lz4FrameDecode(frame);

Streaming frame decode #

final decodedChunks = byteChunksStream.transform(
  lz4FrameDecoder(maxOutputBytes: 128 * 1024 * 1024),
);

License #

Apache-2.0. See LICENSE.