private async Task <bool> SendFrame(byte[] frame)
{
if (!_isConnected)
{
return(await Task.FromResult(false));
}
else
{
if (_analyzerChar != null)
{
_responseFrame = null;
byte[] frameToSend = new byte[8 + frame.Length];
// Imposto l'header
Encoding.ASCII.GetBytes(_frameMarker).CopyTo(frameToSend, 0);
// Imposto il frame da inviare
frame.CopyTo(frameToSend, 4);
// Calcolo e imposto il crc
UInt32 crc = Crc32_STM.CalculateFromBuffer(frameToSend, frameToSend.Length - 4);
ArrConverter.SetBufferFromUInt32(crc, frameToSend, frameToSend.Length - 4);
await _analyzerChar.WriteAsync(frameToSend);
}
else
{
return(await Task.FromResult(false));
}
}
return(await Task.FromResult(true));
}
private async Task <byte[]> ReceiveFrame()
{
const UInt32 waitCommand = 0x00040000;
const UInt32 packetCommand = 0x3F3F3F3F;
const UInt32 bigFileCommand = 0x3F3F0001;
try
{
if (!_isConnected)
{
return(await Task.FromResult(new byte[0]));
}
else
{
bool isWaitCommand = false;
do
{
await Task.Delay(100);
await _analyzerChar.StopUpdatesAsync();
if (_responseFrame == null || _responseFrame.Length == 0)
{
throw new Exception("dimensione della risposta errata!");
}
// Controllo il marker
string marker = Encoding.ASCII.GetString(_responseFrame, 0, 4);
if (marker != _frameMarker)
{
string tmp = "";
foreach (byte data in _responseFrame)
{
tmp += data.ToString("X2");
}
throw new Exception("invalid marker, received: " + tmp);
}
// Controllo il crc
UInt32 crcSent = ArrConverter.GetUInt32FromBuffer(_responseFrame, _responseFrame.Length - 4);
UInt32 crcCalc = Crc32_STM.CalculateFromBuffer(_responseFrame, _responseFrame.Length - 4);
if (crcSent != crcCalc)
{
throw new Exception("invalid crc");
}
// Controllo se ho una risposta con codice di errore
UInt32 errorCode = ArrConverter.GetUInt32FromBuffer(_responseFrame, 4);
if (errorCode != 0)
{
throw new Exception(errorCode.ToString());
}
if (_responseFrame.Length == 16)
{
if (ArrConverter.GetUInt32FromBuffer(_responseFrame, 8) == waitCommand)
{
isWaitCommand = true;
}
}
else if (_responseFrame.Length == 20)
{
if (ArrConverter.GetUInt32FromBuffer(_responseFrame, 8) == packetCommand)
{
int totalSize = (int)ArrConverter.GetUInt32FromBuffer(_responseFrame, 12);
int packetsNum = ((totalSize % 20) == 0) ? (totalSize / 20) : ((totalSize / 20) + 1);
var fullResponse = new byte[totalSize];
// Il device cerca di trasmettere un pacchetto
await _analyzerChar.StartUpdatesAsync();
await SendCommand(packetCommand);
for (var packetIndex = 0; packetIndex < packetsNum; packetIndex++)
{
await Task.Delay(100);
await _analyzerChar.StopUpdatesAsync();
if (_responseFrame == null || _responseFrame.Length == 0)
{
throw new Exception("dimensione della risposta errata!");
}
_responseFrame.CopyTo(fullResponse, 20 * packetIndex);
await _analyzerChar.StartUpdatesAsync();
await SendCommand(packetCommand);
}
return(await Task.FromResult(fullResponse));
}
else if (ArrConverter.GetUInt32FromBuffer(_responseFrame, 8) == bigFileCommand)
{
int totalSize = (int)ArrConverter.GetUInt32FromBuffer(_responseFrame, 12);
int receivedLength = 0;
// Alloco un buffer per l'intero file e il preambolo
// Per adesso ignoro il preambolo e copio soltanto il buffer contenente il file
byte[] fullRespose = new byte[totalSize + 16];
// Il device cerca di trasmettere un pacchetto
await _analyzerChar.StartUpdatesAsync();
await SendCommand(packetCommand);
while (receivedLength < totalSize)
{
await Task.Delay(100);
await _analyzerChar.StopUpdatesAsync();
if (_responseFrame == null || _responseFrame.Length == 0)
{
throw new Exception("dimensione della risposta errata!");
}
// Copio partendo da 12 e poi in base alla dimensione dei pacchetti ricevuti
Buffer.BlockCopy(_responseFrame, 0, fullRespose, receivedLength + 12, _responseFrame.Length);
MessagingCenter.Send <IAnalyzerDevice, double>(this, "DownloadFileProgress", (double)receivedLength / totalSize);
receivedLength += _responseFrame.Length;
await _analyzerChar.StartUpdatesAsync();
await SendCommand(packetCommand);
}
return(await Task.FromResult(fullRespose));
}
}
await _analyzerChar.StartUpdatesAsync();
}while (isWaitCommand);
}
await _analyzerChar.StartUpdatesAsync();
return(await Task.FromResult(_responseFrame));
}
catch (Exception ex)
{
await _analyzerChar.StartUpdatesAsync();
throw ex;
}
}