public override void OnDatagram(Datagram datagram)
{
CheckDatagramValid(datagram);
connection.SendDatagramAsync(datagram.CreateAck());
lock (channelMutex)
{
int relate = RelativeSequenceNumber(datagram.Sequence, recvWindowStart);
if (relate == 0)
{
//right in time
connection.ReleaseDatagram(datagram);
AdvanceWindow();
int nextSeqNr = (datagram.Sequence + 1) % MAX_SEQUENCE;
if (ordered)
{
while (recvWithheld[nextSeqNr % WINDOW_SIZE] != null)
{
connection.ReleaseDatagram(recvWithheld[nextSeqNr % WINDOW_SIZE]);
AdvanceWindow();
nextSeqNr++;
}
}
else
{
while (recvEarlyReceived[nextSeqNr % WINDOW_SIZE])
{
AdvanceWindow();
nextSeqNr++;
}
}
return;
}
if (relate < 0)
{
//duplicate
logger.Trace($"Dropped duplicate {datagram}");
datagram.Dispose();
return;
}
if (relate > WINDOW_SIZE)
{
//too early message
logger.Trace($"Dropped too early {datagram}");
datagram.Dispose();
return;
}
if (ordered)
{
if (recvWithheld[datagram.Sequence % WINDOW_SIZE] != null)
{
//duplicate
logger.Trace($"Dropped duplicate {datagram}");
datagram.Dispose();
return;
}
recvWithheld[datagram.Sequence % WINDOW_SIZE] = datagram;
}
else
{
if (recvEarlyReceived[datagram.Sequence % WINDOW_SIZE])
{
//duplicate
logger.Trace($"Dropped duplicate {datagram}");
datagram.Dispose();
return;
}
recvEarlyReceived[datagram.Sequence % WINDOW_SIZE] = true;
connection.ReleaseDatagram(datagram);
}
}
}