public unsafe void Write(ReadOnlySpan <byte> span)
#endif
{
if (_mode != Mode.Compress)
{
throw new NotSupportedException("Write() not supported on decompression");
}
int inputSize = span.Length;
while (0 < span.Length)
{
int srcWorkSize = _bufferSize < span.Length ? _bufferSize : span.Length;
UIntPtr outSizeVal;
fixed(byte *dest = _workBuf)
fixed(byte *src = span)
{
outSizeVal = LZ4Init.Lib.FrameCompressUpdate(_cctx, dest, (UIntPtr)_destBufSize, src, (UIntPtr)srcWorkSize, null);
}
LZ4FrameException.CheckReturnValue(outSizeVal);
Debug.Assert(outSizeVal.ToUInt64() < int.MaxValue, "BufferSize should be <2GB");
int outSize = (int)outSizeVal.ToUInt64();
BaseStream.Write(_workBuf, 0, outSize);
TotalOut += outSize;
span = span.Slice(srcWorkSize);
}
TotalIn += inputSize;
}
protected override void Dispose(bool disposing)
{
if (disposing && !_disposed)
{
if (_cctx != IntPtr.Zero)
{ // Compress
FinishWrite();
UIntPtr ret = LZ4Init.Lib.FreeFrameCompressContext(_cctx);
LZ4FrameException.CheckReturnValue(ret);
_cctx = IntPtr.Zero;
}
if (_dctx != IntPtr.Zero)
{
UIntPtr ret = LZ4Init.Lib.FreeFrameDecompressContext(_dctx);
LZ4FrameException.CheckReturnValue(ret);
_dctx = IntPtr.Zero;
}
if (BaseStream != null)
{
Flush();
if (!_leaveOpen)
{
BaseStream.Dispose();
}
BaseStream = null;
}
_disposed = true;
}
}
/// <summary>
/// Create decompressing LZ4FrameStream.
/// </summary>
public unsafe LZ4FrameStream(Stream baseStream, LZ4FrameDecompressOptions compOpts)
{
LZ4Init.Manager.EnsureLoaded();
BaseStream = baseStream ?? throw new ArgumentNullException(nameof(baseStream));
_mode = Mode.Decompress;
_disposed = false;
// Check and set compress options
_leaveOpen = compOpts.LeaveOpen;
_bufferSize = CheckBufferSize(compOpts.BufferSize);
// Prepare dctx
UIntPtr ret = LZ4Init.Lib.CreateFrameDecompressContext(ref _dctx, FrameVersion);
LZ4FrameException.CheckReturnValue(ret);
// Remove LZ4 frame header from the baseStream
byte[] headerBuf = new byte[4];
int readHeaderSize = BaseStream.Read(headerBuf, 0, 4);
TotalIn += 4;
if (readHeaderSize != 4 || !headerBuf.SequenceEqual(FrameMagicNumber))
{
throw new InvalidDataException("BaseStream is not a valid LZ4 Frame Format");
}
// Prepare a work buffer
_workBuf = new byte[_bufferSize];
}
private unsafe void FinishWrite()
{
Debug.Assert(_mode == Mode.Compress, "FinishWrite() cannot be called in decompression");
UIntPtr outSizeVal;
fixed(byte *dest = _workBuf)
{
outSizeVal = LZ4Init.Lib.FrameCompressEnd(_cctx, dest, (UIntPtr)_destBufSize, null);
}
LZ4FrameException.CheckReturnValue(outSizeVal);
Debug.Assert(outSizeVal.ToUInt64() < int.MaxValue, "BufferSize should be <2GB");
int outSize = (int)outSizeVal.ToUInt64();
BaseStream.Write(_workBuf, 0, outSize);
TotalOut += outSize;
}
public unsafe int Read(Span <byte> span)
#endif
{
if (_mode != Mode.Decompress)
{
throw new NotSupportedException("Read() not supported on compression");
}
// Reached end of stream
if (_decompSrcIdx == DecompressComplete)
{
return(0);
}
int readSize = 0;
int destSize = span.Length;
int destLeftBytes = span.Length;
if (_firstRead)
{
// Write FrameMagicNumber into LZ4F_decompress
UIntPtr headerSizeVal = (UIntPtr)4;
UIntPtr destSizeVal = (UIntPtr)destSize;
UIntPtr ret;
fixed(byte *header = FrameMagicNumber)
fixed(byte *dest = span)
{
ret = LZ4Init.Lib.FrameDecompress(_dctx, dest, ref destSizeVal, header, ref headerSizeVal, null);
}
LZ4FrameException.CheckReturnValue(ret);
Debug.Assert(headerSizeVal.ToUInt64() <= int.MaxValue);
Debug.Assert(destSizeVal.ToUInt64() <= int.MaxValue);
if (headerSizeVal.ToUInt32() != 4u)
{
throw new InvalidOperationException("Not enough dest buffer");
}
int destWritten = (int)destSizeVal.ToUInt32();
span = span.Slice(destWritten);
TotalOut += destWritten;
_firstRead = false;
}
while (0 < destLeftBytes)
{
if (_decompSrcIdx == _decompSrcCount)
{
// Read from _baseStream
_decompSrcIdx = 0;
_decompSrcCount = BaseStream.Read(_workBuf, 0, _workBuf.Length);
TotalIn += _decompSrcCount;
// _baseStream reached its end
if (_decompSrcCount == 0)
{
_decompSrcIdx = DecompressComplete;
break;
}
}
UIntPtr srcSizeVal = (UIntPtr)(_decompSrcCount - _decompSrcIdx);
UIntPtr destSizeVal = (UIntPtr)(destLeftBytes);
UIntPtr ret;
fixed(byte *src = _workBuf.AsSpan(_decompSrcIdx))
fixed(byte *dest = span)
{
ret = LZ4Init.Lib.FrameDecompress(_dctx, dest, ref destSizeVal, src, ref srcSizeVal, null);
}
LZ4FrameException.CheckReturnValue(ret);
// The number of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
Debug.Assert(srcSizeVal.ToUInt64() <= int.MaxValue);
int srcConsumed = (int)srcSizeVal.ToUInt32();
_decompSrcIdx += srcConsumed;
Debug.Assert(_decompSrcIdx <= _decompSrcCount);
// The number of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
Debug.Assert(destSizeVal.ToUInt64() <= int.MaxValue);
int destWritten = (int)destSizeVal.ToUInt32();
span = span.Slice(destWritten);
destLeftBytes -= destWritten;
TotalOut += destWritten;
readSize += destWritten;
}
return(readSize);
}
private static readonly byte[] FrameMagicNumber = { 0x04, 0x22, 0x4D, 0x18 }; // 0x184D2204 (LE)
#endregion
#region Constructor
/// <summary>
/// Create compressing LZ4FrameStream.
/// </summary>
public unsafe LZ4FrameStream(Stream baseStream, LZ4FrameCompressOptions compOpts)
{
LZ4Init.Manager.EnsureLoaded();
BaseStream = baseStream ?? throw new ArgumentNullException(nameof(baseStream));
_mode = Mode.Compress;
_disposed = false;
// Check and set compress options
_leaveOpen = compOpts.LeaveOpen;
_bufferSize = CheckBufferSize(compOpts.BufferSize);
// Prepare cctx
UIntPtr ret = LZ4Init.Lib.CreateFrameCompressContext(ref _cctx, FrameVersion);
LZ4FrameException.CheckReturnValue(ret);
// Prepare FramePreferences
FramePreferences prefs = new FramePreferences
{
FrameInfo = new FrameInfo
{
BlockSizeId = compOpts.BlockSizeId,
BlockMode = compOpts.BlockMode,
ContentChecksumFlag = compOpts.ContentChecksumFlag,
FrameType = compOpts.FrameType,
ContentSize = compOpts.ContentSize,
DictId = 0,
BlockChecksumFlag = compOpts.BlockChecksumFlag,
},
CompressionLevel = compOpts.Level,
AutoFlush = compOpts.AutoFlush ? 1u : 0u,
FavorDecSpeed = compOpts.FavorDecSpeed ? 1u : 0u,
};
// Query the minimum required size of compress buffer
// _bufferSize is the source size, frameSize is the (required) dest size
UIntPtr frameSizeVal = LZ4Init.Lib.FrameCompressBound((UIntPtr)_bufferSize, prefs);
Debug.Assert(frameSizeVal.ToUInt64() <= int.MaxValue);
uint frameSize = frameSizeVal.ToUInt32();
/*
* if (_bufferSize < frameSize)
* _destBufSize = frameSize;
*/
_destBufSize = (uint)_bufferSize;
if (_bufferSize < frameSize)
{
_destBufSize = frameSize;
}
_workBuf = new byte[_destBufSize];
// Write the frame header into _workBuf
UIntPtr headerSizeVal;
fixed(byte *dest = _workBuf)
{
headerSizeVal = LZ4Init.Lib.FrameCompressBegin(_cctx, dest, (UIntPtr)_bufferSize, prefs);
}
LZ4FrameException.CheckReturnValue(headerSizeVal);
Debug.Assert(headerSizeVal.ToUInt64() < int.MaxValue);
int headerSize = (int)headerSizeVal.ToUInt32();
BaseStream.Write(_workBuf, 0, headerSize);
TotalOut += headerSize;
}