LZ4 for .NET (C++ /CLI)

LZ4 has been written by Yann Collet and the original sources can be found on https://github.com/lz4/lz4
This project contains the original C sources recompiled for (Pure) CLR

How to use

Project contains 3 ways of using the library

non-streaming

Non streaming version, works with managed byte arrays

Example:

  // compress data
  byte[] dataToCompress = ...
  byte[] compressedData = LZ4Helper.Compress(dataToCompress);
  // decompress data
  byte[] decompressedData = LZ4Helper.Decompress(compressedData);

streaming

Streaming version, using the LZ4 Framing Format (v1.4.1).
The compressed data that this stream creates is readable by the lz4 command line tools.

Example:

  // compress data [with content checksum]
  using (LZ4Stream stream = LZ4Stream.CreateCompressor(innerStream, LZ4StreamMode.Write, LZ4FrameBlockMode.Linked, LZ4FrameBlockSize.Max64KB, LZ4FrameChecksumMode.Content, null, false)) {
    // write uncompressed data to the lz4 stream
	// the stream will compress the data and write it to the innerStream
	stream.Write(buffer, 0, buffer.Length);	
  }
  
  // compress data [with block and content checksum, start a new frame after 100 data blocks]
  // note: the lz4 command line tools do NOT support block checksums currently
  using (LZ4Stream stream = LZ4Stream.CreateCompressor(innerStream, LZ4StreamMode.Write, LZ4FrameBlockMode.Linked, LZ4FrameBlockSize.Max64KB, LZ4FrameChecksumMode.Block | LZ4FrameChecksumMode.Content, 100, false)) {
    // write uncompressed data to the lz4 stream
	// the stream will compress the data and write it to the innerStream
	stream.Write(buffer, 0, buffer.Length);	
  }
  
  // decompress data (in read mode)
  using (LZ4Stream stream = LZ4Stream.CreateDecompressor(innerStream, LZ4StreamMode.Read, false)) {
    // the lz4 stream will read the compressed data from the innerStream
    // and return the uncompressed data in 'buffer'
	int bytesRead = stream.Read(buffer, 0, buffer.Length);
  }
  
  // decompress data (in write mode)
  using (LZ4Stream stream = LZ4Stream.CreateDecompressor(innerStream, LZ4StreamMode.Write, false)) {
    // the lz4 stream will decompress the data from 'buffer'
	// and write the uncompressed data to the 'innerStream'
	stream.Write(buffer, 0, buffer.Length);
  }

minimal streaming

Streaming version using a custom minimal frame format.
Based on 'blockStreaming_ringBuffer.c' example from the original lz4 sources.

Compressed data is NOT readable by the lz4 command line tools.

Example:

  // compress data
  using (LZ4MinimalFrameFormatStream stream = new LZ4MinimalFrameFormatStream(tmpFile1, CompressionMode.Compress) {
	// write uncompressed data to the lz4 stream
	// the stream will compress the data and write it to the innerStream
	stream.Write(buffer, 0, buffer.Length);	
  }
  
  // decompress data
  using (LZ4MinimalFrameFormatStream stream = new LZ4MinimalFrameFormatStream(innerStream, CompressionMode.Decompress)) {
    // the lz4 stream will read the compressed data from the innerStream
    // and return the uncompressed data in 'buffer'
	int bytesRead = stream.Read(buffer, 0, buffer.Length)
  }

NOTE:

LZ4MinimalFrameFormatStream contains a ctor to specify the size of the ringbuffer, the ringbuffer used for encoding and decoding need to be sychronized, i.e. use the same (ring)buffer sizes for encoding and decoding.
Although the frame format of LZ4MinimalFrameFormatStream is shorter, it is probably better to use LZ4Stream as it has more options (like a content checksum) and is readable by the lz4 command line tools.

andriniaina/lz4.net

LZ4 for .NET (C++ /CLI)

How to use