private async Task ConnectAsync(CancellationToken token)
{
try
{
await BackOff();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Connecting);
Debug.WriteLine($"opening websocket {_clientWebSocket.GetHashCode()} (thread {Thread.CurrentThread.ManagedThreadId})");
await _clientWebSocket.ConnectAsync(_webSocketUri, token);
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Connected);
Debug.WriteLine($"connection established on websocket {_clientWebSocket.GetHashCode()}, invoking Options.OnWebsocketConnected()");
await(Options.OnWebsocketConnected?.Invoke(_client) ?? Task.CompletedTask);
Debug.WriteLine($"invoking Options.OnWebsocketConnected() on websocket {_clientWebSocket.GetHashCode()}");
_connectionAttempt = 1;
// create receiving observable
_incomingMessages = Observable
.Defer(() => GetReceiveTask().ToObservable().ObserveOn(_receiveLoopScheduler))
.Repeat()
// complete sequence on OperationCanceledException, this is triggered by the cancellation token on disposal
.Catch <WebsocketMessageWrapper, OperationCanceledException>(exception => Observable.Empty <WebsocketMessageWrapper>())
.Publish();
// subscribe maintenance
var maintenanceSubscription = _incomingMessages.Subscribe(_ => { }, ex =>
{
Debug.WriteLine($"incoming message stream {_incomingMessages.GetHashCode()} received an error: {ex}");
_exceptionSubject.OnNext(ex);
_incomingMessagesConnection?.Dispose();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
},
() =>
{
Debug.WriteLine($"incoming message stream {_incomingMessages.GetHashCode()} completed");
_incomingMessagesConnection?.Dispose();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
});
// connect observable
var connection = _incomingMessages.Connect();
Debug.WriteLine($"new incoming message stream {_incomingMessages.GetHashCode()} created");
_incomingMessagesConnection = new CompositeDisposable(maintenanceSubscription, connection);
}
catch (Exception e)
{
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
_exceptionSubject.OnNext(e);
throw;
}
}
private async Task ConnectAsync(CancellationToken token)
{
try
{
await BackOff();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Connecting);
Debug.WriteLine($"opening websocket {_clientWebSocket.GetHashCode()} (thread {Thread.CurrentThread.ManagedThreadId})");
await _clientWebSocket.ConnectAsync(_webSocketUri, token);
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Connected);
Debug.WriteLine($"connection established on websocket {_clientWebSocket.GetHashCode()}, invoking Options.OnWebsocketConnected()");
await(Options.OnWebsocketConnected?.Invoke(_client) ?? Task.CompletedTask);
Debug.WriteLine($"invoking Options.OnWebsocketConnected() on websocket {_clientWebSocket.GetHashCode()}");
_connectionAttempt = 1;
// create receiving observable
_incomingMessages = Observable
.Defer(() => GetReceiveTask().ToObservable())
.Repeat()
// complete sequence on OperationCanceledException, this is triggered by the cancellation token on disposal
.Catch <WebsocketMessageWrapper, OperationCanceledException>(exception => Observable.Empty <WebsocketMessageWrapper>())
.Publish();
// subscribe maintenance
var maintenanceSubscription = _incomingMessages.Subscribe(_ => { }, ex =>
{
Debug.WriteLine($"incoming message stream {_incomingMessages.GetHashCode()} received an error: {ex}");
_exceptionSubject.OnNext(ex);
_incomingMessagesConnection?.Dispose();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
},
() =>
{
Debug.WriteLine($"incoming message stream {_incomingMessages.GetHashCode()} completed");
_incomingMessagesConnection?.Dispose();
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
});
// connect observable
var connection = _incomingMessages.Connect();
Debug.WriteLine($"new incoming message stream {_incomingMessages.GetHashCode()} created");
_incomingMessagesConnection = new CompositeDisposable(maintenanceSubscription, connection);
var initRequest = new GraphQLWebSocketRequest
{
Type = GraphQLWebSocketMessageType.GQL_CONNECTION_INIT,
Payload = Options.ConfigureWebSocketConnectionInitPayload(Options)
};
// setup task to await connection_ack message
var ackTask = _incomingMessages
.Where(response => response != null)
.TakeUntil(response => response.Type == GraphQLWebSocketMessageType.GQL_CONNECTION_ACK ||
response.Type == GraphQLWebSocketMessageType.GQL_CONNECTION_ERROR)
.FirstAsync()
.ToTask();
// send connection init
Debug.WriteLine($"sending connection init message");
await SendWebSocketMessageAsync(initRequest);
var response = await ackTask;
if (response.Type == GraphQLWebSocketMessageType.GQL_CONNECTION_ACK)
{
Debug.WriteLine($"connection acknowledged: {Encoding.UTF8.GetString(response.MessageBytes)}");
}
else
{
var errorPayload = Encoding.UTF8.GetString(response.MessageBytes);
Debug.WriteLine($"connection error received: {errorPayload}");
throw new GraphQLWebsocketConnectionException(errorPayload);
}
}
catch (Exception e)
{
Debug.WriteLine($"failed to establish websocket connection");
_stateSubject.OnNext(GraphQLWebsocketConnectionState.Disconnected);
_exceptionSubject.OnNext(e);
throw;
}
}