public static byte[] Compress(byte[] b)
{
using (var compressor = new ZstdNet.Compressor())
{
return(compressor.Wrap(b));
}
}
protected override byte[] Compress(MemoryStream uncompressed)
{
MemoryStream output = new MemoryStream();
output.Write(Header, 0, Header.Length);
var comp = new ZstdNet.Compressor();
var compressed = comp.Wrap(uncompressed.ToArray());
output.Write(BitConverter.GetBytes(compressed.Length + 9), 0, 4);
output.Write(BitConverter.GetBytes(uncompressed.Length), 0, 4);
output.Write(compressed, 0, compressed.Length);
return(output.ToArray());
}
public static void WriteToFile(string filename, string data)
{
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
var compressor = new ZstdNet.Compressor(new ZstdNet.CompressionOptions(20));
File.WriteAllBytes(filename + ".zst", compressor.Wrap(System.Text.Encoding.UTF8.GetBytes(data)));
}
else
{
// Annoyingly this doesn't currently work on Linux.
// TODO: come up with a better solution.
File.WriteAllBytes(filename, System.Text.Encoding.UTF8.GetBytes(data));
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.FileName = "zstd";
startInfo.Arguments = filename;
var process = Process.Start(startInfo);
process.WaitForExit();
}
}
public void WriteTo(BinaryWriter dataWriter, BinaryWriter metadataWriter, bool asDuplicate)
{
uint actualsize = 0;
uint crc = 0;
ulong offset = (ulong)dataWriter.BaseStream.Position;
if (!asDuplicate)
{
using (MemoryStream buffer = new MemoryStream())
using (Stream source = Source.GetStream())
{
switch (Compression)
{
case ArchiveFileCompression.LZ4:
using (LZ4Stream lz = new LZ4Stream(buffer, LZ4StreamMode.Compress, LZ4StreamFlags.HighCompression | LZ4StreamFlags.IsolateInnerStream, 4 * 1048576))
source.CopyTo(lz);
break;
case ArchiveFileCompression.Zstandard:
using (ZstdNet.Compressor zstd = new ZstdNet.Compressor(new ZstdNet.CompressionOptions(3)))
using (MemoryStream temp = new MemoryStream())
{
source.CopyTo(temp);
byte[] output = zstd.Wrap(temp.ToArray());
buffer.Write(output, 0, output.Length);
}
break;
case ArchiveFileCompression.Uncompressed:
source.CopyTo(buffer);
break;
default:
throw new InvalidOperationException("Compression type is invalid.");
}
buffer.Position = 0;
byte[] bBuffer = buffer.ToArray();
crc = Crc32CAlgorithm.Compute(bBuffer);
dataWriter.Write(bBuffer);
}
long newsize = dataWriter.BaseStream.Position;
actualsize = (uint)(newsize - (long)offset);
}
metadataWriter.Write((byte)Type);
metadataWriter.Write((byte)Flags);
if (asDuplicate)
{
metadataWriter.Write((byte)ArchiveFileCompression.Duplicate);
}
else
{
metadataWriter.Write((byte)Compression);
}
metadataWriter.Write((byte)0); //reserved
metadataWriter.Write(crc);
metadataWriter.Write(Source.Md5);
metadataWriter.BaseStream.Seek(48, SeekOrigin.Current);
byte[] uName = Encoding.Unicode.GetBytes(Name);
metadataWriter.Write((ushort)uName.Length);
metadataWriter.Write(uName);
metadataWriter.Write(offset);
metadataWriter.Write(Source.Size);
metadataWriter.Write(actualsize);
}
public ZstdCompressor(int compressionLevel) : base(compressionLevel)
{
BaseCompressor = new ZstdNet.Compressor(new ZstdNet.CompressionOptions(CompressionLevel));
}
