private void HandleMessage(GcMessage message)
{
MessageHandler handler;
_messageHandlers.TryGetValue(message.OpCode, out handler);
if (handler == null && message.RequiresResponse)
{
// No handler, but message requires a response
message.Respond(ResponseStatus.NotHandled, "Not handled");
return;
}
// No handler, but don't need to respond
if (handler == null)
{
return;
}
Task.Run(async() =>
{
try
{
await handler.Invoke(message);
}
catch (Exception e)
{
_logger.LogError("Exception while handling a request", e);
try
{
if (message.RequiresResponse)
{
message.Respond(ResponseStatus.Error, "Internal error");
}
}
catch (Exception responseException)
{
_logger.LogError("Exception while trying to respond after " +
"catching an exception", responseException);
}
}
});
}
public GcConnection(IConnectionImplementation implementation)
{
// Generate instance id for better hashing
_instanceId = Interlocked.Increment(ref _instanceIdGenerator);
_relayedPeers = new ConcurrentDictionary <int, GcPeer>();
_responseCallbacks = new ConcurrentDictionary <int, TaskCompletionSource <GcMessage> >();
_timeoutMessage = new GcMessage(null, 0)
{
Status = ResponseStatus.Timeout
};
Implementation = implementation;
implementation.DataReceived += OnDataReceived;
implementation.Disconnected += OnDisconnected;
_writer = new NetWriter();
}
public static GcMessage ParseMessage(GcPeer peer, byte[] data)
{
var reader = new NetReader(data);
var flags = reader.ReadByte();
var opCode = reader.ReadInt16();
// Read peer id if it's provided
if ((flags & MessageFlags.PaddedPeerId) > 0)
{
// Read padded peer id
reader.ReadInt32();
}
var msg = new GcMessage(peer, flags)
{
OpCode = opCode,
Reader = reader
};
if ((flags & MessageFlags.Request) > 0)
{
var requestId = reader.ReadInt32();
msg.RequestId = requestId;
}
if ((flags & MessageFlags.Response) > 0)
{
var responseId = reader.ReadInt32();
var responseStatus = (ResponseStatus)reader.ReadByte();
msg.ResponseId = responseId;
msg.Status = responseStatus;
}
return(msg);
}
private async Task HandleEstablishPeer(GcMessage message)
{
var peerId = message.Reader.ReadInt32();
var isDirectMessage = peerId < 0;
GcPeer peer = null;
if (isDirectMessage)
{
// This is a direct message from client
// who can't know his peer id
peerId = message.Peer.PeerId;
peer = message.Peer;
}
else
{
// This is a message that was already relayed at least once
// We need to create a virtual peer which will be used in this server
var vPeer = new GcPeer(Interlocked.Increment(ref _peerIdGenerator), message.Peer);
_peers.TryAdd(vPeer.PeerId, vPeer);
PeerJoined?.Invoke(vPeer);
// Add the newly created peer id
peerId = vPeer.PeerId;
peer = vPeer;
}
// Send messages to all of the relayed servers to establish a peer in them
var connections = _relayConnections.Values.Distinct().Where(c => c.IsConnected);
var allSuccessful = true;
// Do it "linearly" (one by one) because it's a lot easier to handle
foreach (var connection in connections)
{
var response =
await connection.SendRequest((short)InternalOpCodes.EstablishPeer, w => w.Write(peerId));
if (response.Status != ResponseStatus.Success)
{
_logger.LogWarning("Failed to establish a peer in connection: " + connection);
allSuccessful = false;
continue;
}
var assignedPeerId = response.Reader.ReadInt32();
// For forwarding messages
peer.SetPeerIdInRelayedServer(assignedPeerId, connection);
// For "backwarding" messages
connection.SaveRelayedPeer(assignedPeerId, peer);
}
if (isDirectMessage)
{
message.Respond(allSuccessful ? ResponseStatus.Success : ResponseStatus.Failed);
}
else
{
message.Respond(ResponseStatus.Success, w => w.Write(peerId));
}
}
