public static byte[] Decompress(byte[] buffer, byte[] sourceChunkData)
{
using (MemoryStream ms = new MemoryStream(buffer))
using (BinaryReader reader = new BinaryReader(ms))
{
if (reader.ReadUInt16() != VZipHeader)
{
throw new Exception("Expecting VZipHeader at start of stream");
}
if (reader.ReadChar() != Version)
{
throw new Exception("Expecting VZip version 'd'");
}
// This is also the CRC of the chunk
/* uint secondaryCRC = */ reader.ReadUInt32();
byte[] properties = reader.ReadBytes(5);
byte[] deltaBuffer = reader.ReadBytes(( int )ms.Length - HeaderLength - FooterLength - 5);
uint outputCRC = reader.ReadUInt32();
uint sizeDecompressed = reader.ReadUInt32();
if (reader.ReadUInt16() != VZipFooter)
{
throw new Exception("Expecting VZipFooter at end of stream");
}
SevenZip.Compression.LZMA.Decoder decoder = new SevenZip.Compression.LZMA.Decoder(allowIllegalStreamStart: true);
decoder.SetDecoderProperties(properties);
using (MemoryStream trainingStream = new MemoryStream(sourceChunkData))
using (MemoryStream inputStream = new MemoryStream(deltaBuffer))
using (MemoryStream outStream = new MemoryStream(( int )sizeDecompressed))
{
decoder.Train(trainingStream);
decoder.Code(inputStream, outStream, deltaBuffer.Length, sizeDecompressed, null);
var outData = outStream.ToArray();
if (Crc32.Compute(outData) != outputCRC)
{
throw new InvalidDataException("CRC does not match decompressed data. VZip data may be corrupted.");
}
return(outData);
}
}
}