protected override byte[] Decompress(Stream compressed, out UInt128 compressedHash)
{
var header = new byte[9];
int read = 0;
do
{
read += compressed.Read(header, read, header.Length - read);
} while (read < header.Length);
if (header[0] != Header[0])
{
throw new FormatException($"Invalid header value {header[0]}");
}
var compressedSize = BitConverter.ToInt32(header, 1);
var uncompressedSize = BitConverter.ToInt32(header, 5);
read = 0;
compressedSize -= header.Length;
var compressedBytes = new byte[compressedSize + header.Length];
Array.Copy(header, 0, compressedBytes, 0, header.Length);
do
{
read += compressed.Read(compressedBytes, header.Length + read, compressedSize - read);
} while (read < compressedSize);
compressedHash = ClickHouseCityHash.CityHash128(compressedBytes);
return(LZ4Codec.Decode(compressedBytes, header.Length, compressedSize, uncompressedSize));
}
public override void EndCompression()
{
var compressed = Compress(_uncompressed);
var hash = ClickHouseCityHash.CityHash128(compressed);
_baseStream.Write(BitConverter.GetBytes(hash.Low), 0, 8);
_baseStream.Write(BitConverter.GetBytes(hash.High), 0, 8);
_baseStream.Write(compressed, 0, compressed.Length);
}