public GameClient(string address, int port)
{
_udp = new UdpClient(0)
{
Client = { Blocking = false }
};
_target = new IPEndPoint(IPAddress.Parse(address), port);
_server = new NetworkConnection(_udp, _target);
_server.MessageReceived += (fromAddr, message) => MessageReceived?.Invoke(fromAddr, message);
_server.ClientDisconnected += (fromAddr) => ServerDisconnected?.Invoke(fromAddr);
_server.MessageAcked += (fromAddr, message) => MessageAcked?.Invoke(fromAddr, message);
_server.MessageLost += (fromAddr, message) => MessageLost?.Invoke(fromAddr, message);
_reliable = new ReliableConnection(_server);
_reliable.ReliableMessageRecieved += (fromAddr, message) => ReliableMessageReceived?.Invoke(fromAddr, message);
}
private void HandleNewClientConnection(IPEndPoint clientAddr)
{
_clients[clientAddr] = new NetworkConnection(_udp, clientAddr);
_clients[clientAddr].MessageReceived += (fromAddr, message) => MessageReceived?.Invoke(fromAddr, message);
_clients[clientAddr].ClientDisconnected += (fromAddr) =>
{
_clients.Remove(fromAddr);
_reliableClients.Remove(fromAddr);
ClientDisconnected?.Invoke(fromAddr);
};
_clients[clientAddr].MessageAcked += (fromAddr, message) => MessageAcked?.Invoke(fromAddr, message);
_clients[clientAddr].MessageLost += (fromAddr, message) => MessageLost?.Invoke(fromAddr, message);
_reliableClients[clientAddr] = new ReliableConnection(_clients[clientAddr]);
_reliableClients[clientAddr].ReliableMessageRecieved += (fromAddr, message) => ReliableMessageReceived?.Invoke(fromAddr, message);
ClientConnected?.Invoke(clientAddr);
}
public void EnqueueReceive(IPEndPoint fromAddr, byte[] packet)
{
// Reset timeout accumulator - we just got a packet.
_timeoutAccumulator = 0;
_connected = true;
// Read the sequence, ack and ack bitfield. In this case, the sequence
// is the remote connection's sequence - and thus the sequence number
// we will be acknowledging. Meanwhile the acks are for the messages
// that we sent out.
var remoteSeq = BitConverter.ToUInt16(packet, 0);
var remoteAck = BitConverter.ToUInt16(packet, sizeof(ushort));
var remoteAckBitfield = BitConverter.ToUInt32(packet, sizeof(ushort) * 2);
/*******
*
* WARNING! This code does not handle sequence number overflow. Refer to
* https://web.archive.org/web/20181107181433/https://gafferongames.com/post/reliability_ordering_and_congestion_avoidance_over_udp/#handling-sequence-number-wrap-around
* for information on how to handle this.
*
********/
// Update our acknowledgement of packets the remote machine sent.
var lastGot = _ackSeq;
var nowGot = remoteSeq;
if (nowGot == lastGot)
{
// Remote acknowledgement is in the same state, nothing to do.
}
else
{
// We need to move the acknowledgement of the packet we last got
// into the bitfield first.
_ackBitField <<= 1;
_ackBitField |= 0x1;
// Shift bitfield across for all the packets we lost in between.
if (nowGot - lastGot > 1)
{
_ackBitField <<= (nowGot - lastGot) - 1;
}
}
_ackSeq = remoteSeq;
// Read the acknowledgement data from the remote machine about packets we sent.
if (_pendingSendAcks.ContainsKey(remoteAck))
{
// If it's in the ack field, the remote machine received it.
foreach (var message in _pendingSendAcks[remoteAck])
{
MessageAcked?.Invoke(_target, message);
}
_pendingSendAcks.Remove(remoteAck);
}
for (var i = 0; i < sizeof(uint); i++)
{
var seqInBitfield = (ushort)(remoteAck - i - 1);
var isAcked = ((remoteAckBitfield >> i) & 0x1) == 0x1;
if (_pendingSendAcks.ContainsKey(seqInBitfield))
{
foreach (var message in _pendingSendAcks[seqInBitfield])
{
if (isAcked)
{
MessageAcked?.Invoke(_target, message);
}
else
{
MessageLost?.Invoke(_target, message);
}
}
}
_pendingSendAcks.Remove(seqInBitfield);
}
// Take the raw packet and split it out into the messages it contains.
var offset = PACKET_HEADER_SIZE_BYTES;
while (offset < packet.Length)
{
var len = BitConverter.ToUInt16(packet, offset);
offset += 2;
var message = new byte[len];
Array.Copy(packet, offset, message, 0, len);
offset += len;
MessageReceived?.Invoke(fromAddr, message);
}
}