/// <inheritdoc />
public override async Task OnConnectedAsync(ConnectionContext connection)
{
// We check to see if HubOptions<THub> are set because those take precedence over global hub options.
// Then set the keepAlive and handshakeTimeout values to the defaults in HubOptionsSetup when they were explicitly set to null.
var supportedProtocols = _hubOptions.SupportedProtocols ?? _globalHubOptions.SupportedProtocols;
if (supportedProtocols == null || supportedProtocols.Count == 0)
{
throw new InvalidOperationException("There are no supported protocols");
}
var handshakeTimeout = _hubOptions.HandshakeTimeout ?? _globalHubOptions.HandshakeTimeout ?? HubOptionsSetup.DefaultHandshakeTimeout;
var contextOptions = new HubConnectionContextOptions()
{
KeepAliveInterval = _hubOptions.KeepAliveInterval ?? _globalHubOptions.KeepAliveInterval ?? HubOptionsSetup.DefaultKeepAliveInterval,
ClientTimeoutInterval = _hubOptions.ClientTimeoutInterval ?? _globalHubOptions.ClientTimeoutInterval ?? HubOptionsSetup.DefaultClientTimeoutInterval,
StreamBufferCapacity = _hubOptions.StreamBufferCapacity ?? _globalHubOptions.StreamBufferCapacity ?? HubOptionsSetup.DefaultStreamBufferCapacity,
MaximumReceiveMessageSize = _maximumMessageSize,
SystemClock = SystemClock,
MaximumParallelInvocations = _maxParallelInvokes,
};
Log.ConnectedStarting(_logger);
var connectionContext = new HubConnectionContext(connection, contextOptions, _loggerFactory);
var resolvedSupportedProtocols = (supportedProtocols as IReadOnlyList <string>) ?? supportedProtocols.ToList();
if (!await connectionContext.HandshakeAsync(handshakeTimeout, resolvedSupportedProtocols, _protocolResolver, _userIdProvider, _enableDetailedErrors))
{
return;
}
// -- the connectionContext has been set up --
try
{
await _lifetimeManager.OnConnectedAsync(connectionContext);
await RunHubAsync(connectionContext);
}
finally
{
connectionContext.Cleanup();
Log.ConnectedEnding(_logger);
await _lifetimeManager.OnDisconnectedAsync(connectionContext);
}
}
private async Task HubOnDisconnectedAsync(HubConnectionContext connection, Exception?exception)
{
// send close message before aborting the connection
await SendCloseAsync(connection, exception, connection.AllowReconnect);
// We wait on abort to complete, this is so that we can guarantee that all callbacks have fired
// before OnDisconnectedAsync
// Ensure the connection is aborted before firing disconnect
await connection.AbortAsync();
try
{
await _dispatcher.OnDisconnectedAsync(connection, exception);
}
catch (Exception ex)
{
Log.ErrorDispatchingHubEvent(_logger, "OnDisconnectedAsync", ex);
throw;
}
}
private async Task RunHubAsync(HubConnectionContext connection)
{
try
{
await _dispatcher.OnConnectedAsync(connection);
}
catch (Exception ex)
{
Log.ErrorDispatchingHubEvent(_logger, "OnConnectedAsync", ex);
// The client shouldn't try to reconnect given an error in OnConnected.
await SendCloseAsync(connection, ex, allowReconnect : false);
// return instead of throw to let close message send successfully
return;
}
try
{
await DispatchMessagesAsync(connection);
}
catch (OperationCanceledException)
{
// Don't treat OperationCanceledException as an error, it's basically a "control flow"
// exception to stop things from running
}
catch (Exception ex)
{
Log.ErrorProcessingRequest(_logger, ex);
await HubOnDisconnectedAsync(connection, ex);
// return instead of throw to let close message send successfully
return;
}
await HubOnDisconnectedAsync(connection, connection.CloseException);
}
private async Task SendCloseAsync(HubConnectionContext connection, Exception?exception, bool allowReconnect)
{
var closeMessage = CloseMessage.Empty;
if (exception != null)
{
var errorMessage = ErrorMessageHelper.BuildErrorMessage("Connection closed with an error.", exception, _enableDetailedErrors);
closeMessage = new CloseMessage(errorMessage, allowReconnect);
}
else if (allowReconnect)
{
closeMessage = new CloseMessage(error: null, allowReconnect);
}
try
{
await connection.WriteAsync(closeMessage, ignoreAbort : true);
}
catch (Exception ex)
{
Log.ErrorSendingClose(_logger, ex);
}
}