public async Task <bool> TryHandleReceivedMessage(CoapMessage message)
{
if (message is null)
{
throw new ArgumentNullException(nameof(message));
}
try
{
var observeOption = message.Options.FirstOrDefault(o => o.Number == CoapMessageOptionNumber.Observe);
if (observeOption == null)
{
return(false);
}
if (!_observedResponseHandlers.TryGetValue(new CoapMessageToken(message.Token), out var responseHandler))
{
await DeregisterObservation(message).ConfigureAwait(false);
return(true);
}
if (message.Type == CoapMessageType.Confirmable)
{
var ackMessage = new CoapMessage
{
Type = CoapMessageType.Acknowledgement,
Code = CoapMessageCodes.Empty,
Id = message.Id
};
await _client.SendAsync(ackMessage, CancellationToken.None).ConfigureAwait(false);
}
var payload = message.Payload;
// TODO: Check if supported etc.
//if (CoapClientBlockTransferReceiver.IsBlockTransfer(coapMessage))
//{
// payload = await new CoapClientBlockTransferReceiver(requestMessage, coapMessage, this, _logger).ReceiveFullPayload(CancellationToken.None).ConfigureAwait(false);
//}
var sequenceNumber = ((CoapMessageOptionUintValue)observeOption.Value).Value;
var response = _messageToResponseConverter.Convert(message, payload);
await responseHandler.HandleResponseAsync(new HandleResponseContext
{
SequenceNumber = sequenceNumber,
Response = response
}).ConfigureAwait(false);
return(true);
}
catch (Exception exception)
{
_logger.Error(nameof(CoapClient), exception, "Error while handling observed message.");
return(false);
}
}
async Task ReceiveMessages(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var message = await _lowLevelClient.ReceiveAsync(cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (message == null)
{
continue;
}
if (!_messageDispatcher.TryHandleReceivedMessage(message))
{
if (!await _observationManager.TryHandleReceivedMessage(message).ConfigureAwait(false))
{
_logger.Trace(nameof(CoapClient), "Received an unexpected message ({0}).", message.Id);
}
}
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(nameof(CoapClient), exception, "Error while receiving messages.");
}
}
}
async Task ReceiveMessages(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var message = await _lowLevelClient.ReceiveAsync(cancellationToken).ConfigureAwait(false);
if (!_messageDispatcher.TryDispatch(message))
{
if (!await TryHandleObservedMessage(message).ConfigureAwait(false))
{
await DeregisterObservation(message).ConfigureAwait(false);
}
}
}
catch (Exception exception)
{
_logger.Error(nameof(CoapClient), exception, "Error while receiving message.");
}
}
}