/// <summary> Detects acknowledged and lost messages. </summary>
private void AckDelivered(NetHeader header)
{
for (int i = 0; i < sendWindow.Count; i++)
{
int seqDist = NetMath.SeqDistance(sendWindow[i], header.AckSequence);
// This AckSequence is older than the sendWindow's, not useful:
if (seqDist > 0)
{
break;
}
// AckHistory has rolled over without acking this message; Ordered reliable is broken:
if (seqDist <= -64)
{
Connection.Disconnect();
}
// If the seqDistance corresponds to a true bit in the AckHistory, message delivered/acked:
else if (IsAcked(header.AckHistory, seqDist))
{
MessageDelivered(i, header);
i--; // Since the sendWindow count will decrease, the index needs to be adjusted.
}
// The seqDist is still within the send window, but if too much time has passed, assume lost:
else if (NetTime.Milliseconds() - sendWindowTime[i] > 333)
{
MessageLost(i);
}
}
}
/// <summary> Handles a stream based on its header/size. Determines if it should be buffered if out-of-order,
/// acked and released if size is equal to header size (ack only), or delivered immediately. </summary>
internal void RouteIncomingStream(NetStream strm)
{
var header = NetHeader.FromStream(strm);
int seqDist = NetMath.SeqDistance(header.ObjSequence, LastAcceptedRemoteSequence);
// If the stream is only the size of a header, it's likely a forced ack:
if (strm.Length <= 120)
{
AckDelivered(header);
strm.Release();
}
else if (!RemoteSequenceValid(seqDist))
{
strm.Release();
}
else if (seqDist != 1)
{
BufferOutOfOrder(seqDist, strm, header);
}
else
{
AckReceived(header);
AckDelivered(header);
DeliverStream(strm);
}
}
/// <summary> Acknowledges and updates the remote sequence. </summary>
private void AckReceived(NetHeader header)
{
int newestDist = NetMath.SeqDistance(header.ObjSequence, NewestRemoteSequence);
// If the sequence is newest, shift the buffer and apply ack bit:
if (newestDist > 0)
{
AckHistory = (AckHistory << newestDist) | 1UL;
NewestRemoteSequence = header.ObjSequence;
}
// Else, shift the ack bit and apply to buffer:
else
{
AckHistory |= 1UL << -newestDist;
}
LastReceiveTime = NetTime.Milliseconds();
ReceivedSinceLastSend++;
Received++;
}
