private ErrorCode WriteReadBytesCommand(UsbEndpointBase endpoint)
{
UsbPacket usbPacket = CreateReadBytesCommandPacket();
UsbTransfer transfer = null;
try
{
ErrorCode errorCode = endpoint.SubmitAsyncTransfer(usbPacket, 0, (int)(_usbPacketSizeWithoutData + usbPacket.uiDataLen), _transferTimeoutInMilliseconds, out transfer);
if (errorCode != ErrorCode.None)
{
return(errorCode);
}
WaitHandle.WaitAll(new[] { transfer.AsyncWaitHandle }, _waitTimeout, false);
if (!transfer.IsCompleted)
{
transfer.Cancel();
}
int bytesTransferred;
return(transfer.Wait(out bytesTransferred));
}
finally
{
transfer?.Dispose();
}
}
private unsafe ReadUsbPacketResult ReadUsbPacket(UsbEndpointBase endpoint)
{
UsbTransfer transfer = null;
try
{
var usbPacketBuffer = new byte[_usbPacketSize];
ErrorCode errorCode = endpoint.SubmitAsyncTransfer(usbPacketBuffer, 0, usbPacketBuffer.Length, _transferTimeoutInMilliseconds, out transfer);
if (errorCode != ErrorCode.None)
{
_error.OnNext(errorCode);
return(new ReadUsbPacketResult(errorCode));
}
WaitHandle.WaitAll(new[] { transfer.AsyncWaitHandle }, _waitTimeout, false);
if (!transfer.IsCompleted)
{
transfer.Cancel();
}
int bytesTransferred;
errorCode = transfer.Wait(out bytesTransferred);
if (bytesTransferred == 0)
{
return(new ReadUsbPacketResult(errorCode));
}
GCHandle gcHandle = GCHandle.Alloc(usbPacketBuffer, GCHandleType.Pinned);
var usbPacket = Marshal.PtrToStructure <UsbPacket>(gcHandle.AddrOfPinnedObject());
if (usbPacket.uiSeqNum != _sequenceNumber)
{
_incorrectSequenceNumberReceived.OnNext(new IncorrectSequenceNumberReceivedArgs(_sequenceNumber, usbPacket.uiSeqNum));
return(new ReadUsbPacketResult(errorCode));
}
_sequenceNumber++;
if (bytesTransferred < _usbPacketSizeWithoutData)
{
_incorrectNumberOfBytesReceived.OnNext(bytesTransferred);
return(new ReadUsbPacketResult(errorCode));
}
if (errorCode != ErrorCode.None)
{
return(new ReadUsbPacketResult(errorCode));
}
if (usbPacket.uiDataLen == 0)
{
_noData.OnNext(Unit.Default);
return(new ReadUsbPacketResult(errorCode));
}
_fileOffset += usbPacket.uiDataLen;
var strokes = new List <Stroke>();
var dataBuffer = new byte[usbPacket.uiDataLen];
Marshal.Copy(new IntPtr(usbPacket.pData), dataBuffer, 0, dataBuffer.Length);
for (var i = 0; i < dataBuffer.Length; i += 8)
{
strokes.Add(new Stroke(dataBuffer[i], dataBuffer[i + 1], dataBuffer[i + 2], dataBuffer[i + 3]));
}
return(new ReadUsbPacketResult(errorCode, strokes));
}
finally
{
transfer?.Dispose();
}
}