private static bool IsAnythingReceived(SocketReceiveResult result) => result != null && result.ContentBytes != null && result.ContentBytes.Length != 0;
private async Task ConnectionLoopAsync()
{
Exception closeException = null;
try
{
_lastMessageID = 7;
_connectionCts = new CancellationTokenSource();
ArraySegment <byte> buffer = new ArraySegment <byte>(new byte[1024]);
while (_connectionCts?.Token.IsCancellationRequested != true)
{
// read from stream
SocketReceiveResult receivedMessage = await ReceiveAsync(buffer, _connectionCts.Token).ConfigureAwait(false);
if (!IsAnythingReceived(receivedMessage))
{
continue;
}
// parse the message
if (receivedMessage.MessageType == WebSocketMessageType.Text)
{
SocketMessage msg = SocketMessage.Parse(this.MessageEncoding.GetString(receivedMessage.ContentBytes));
// if message is binary, read them from stream as well
List <byte[]> binaryMessages = new List <byte[]>(msg.BinaryMessagesCount);
for (int i = 0; i < msg.BinaryMessagesCount; i++)
{
SocketReceiveResult receivedBinaryMessage = await ReceiveAsync(buffer, _connectionCts.Token).ConfigureAwait(false);
if (!IsAnythingReceived(receivedBinaryMessage))
{
continue;
}
if (receivedBinaryMessage.MessageType == WebSocketMessageType.Text)
{
throw new InvalidDataException("Received a text message while a binary message was expected");
}
binaryMessages.Add(receivedBinaryMessage.ContentBytes);
}
// raise event
OnTextMessageReceived(msg, binaryMessages);
}
else
{
throw new InvalidDataException("Received a binary message while a text message was expected");
}
}
}
catch (Exception ex)
{
closeException = ex;
// ignore premature close and task cancellations
// these should be treated as normal close event, not an error
if (!IsClosedPrematurelyException(ex) && !(ex is OperationCanceledException))
{
ErrorRaised?.Invoke(this, new UnhandledExceptionEventArgs(ex, true));
}
}
finally
{
// craft closed event, keeping the exception in mind
WebSocketCloseStatus status = _websocketClient?.CloseStatus ?? // websocketclient reported status has priority
(IsClosedPrematurelyException(closeException) ? WebSocketCloseStatus.ProtocolError : // if premature close, report as protocol error
(closeException is OperationCanceledException) ? WebSocketCloseStatus.NormalClosure : // if operation canceled, report as normal closure
WebSocketCloseStatus.Empty); // otherwise report unknown status
string message = _websocketClient?.CloseStatusDescription ?? closeException?.Message;
// clear cancels and nulls cts, so IsConnected will start returning false
this.Clear();
Disconnected?.Invoke(this, new SocketClosedEventArgs(status, message, closeException));
}
}
