public LZ4EncoderStream(
Stream inner,
ILZ4FrameInfo frameInfo,
Func <ILZ4FrameInfo, ILZ4Encoder> encoderFactory,
bool leaveOpen = false)
{
_inner = inner;
_frameInfo = frameInfo;
_encoderFactory = encoderFactory;
_leaveOpen = leaveOpen;
}
private void ReadFrame()
{
Read0();
var magic = TryRead32();
if (magic != 0x184D2204)
{
throw MagicNumberExpected();
}
Read0();
var FLG_BD = Read16();
var FLG = FLG_BD & 0xFF;
var BD = (FLG_BD >> 8) & 0xFF;
var version = (FLG >> 6) & 0x11;
if (version != 1)
{
throw UnknownFrameVersion(version);
}
var blockChaining = ((FLG >> 5) & 0x01) == 0;
var blockChecksum = ((FLG >> 4) & 0x01) != 0;
var hasContentSize = ((FLG >> 3) & 0x01) != 0;
var contentChecksum = ((FLG >> 2) & 0x01) != 0;
var blockSizeCode = (BD >> 4) & 0x07;
var contentLength = hasContentSize ? (long?)Read64() : null;
var actualHC = (byte)(XXH32.DigestOf(_buffer16, 0, _index16) >> 8);
var expectedHC = Read8();
if (actualHC != expectedHC)
{
throw InvalidHeaderChecksum();
}
var blockSize = MaxBlockSize(blockSizeCode);
_frameInfo = new LZ4FrameInfo(contentLength, contentChecksum, blockChaining, blockChecksum, blockSize);
_decoder = _decoderFactory(_frameInfo);
_buffer = new byte[blockSize];
}
private void CloseFrame()
{
if (_decoder == null)
{
return;
}
try
{
_frameInfo = null;
_buffer = null;
// if you need any exceptions throw them here
_decoder.Dispose();
}
finally
{
_decoder = null;
}
}
