public async Task ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken)
{
if (options is null)
{
throw new ArgumentNullException(nameof(options));
}
if (_adapter != null)
{
throw new InvalidOperationException("Low level MQTT client is already connected. Disconnect first before connecting again.");
}
var newAdapter = _clientAdapterFactory.CreateClientAdapter(options);
try
{
_logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
await newAdapter.ConnectAsync(options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
_logger.Verbose("Connection with server established.");
_options = options;
}
catch (Exception)
{
_adapter?.Dispose();
throw;
}
_adapter = newAdapter;
}
public void Dispose()
{
_cancellationTokenSource?.Dispose();
_cancellationTokenSource = null;
_adapter?.Dispose();
}
private void Cleanup()
{
_backgroundCancellationTokenSource?.Cancel(false);
_backgroundCancellationTokenSource?.Dispose();
_backgroundCancellationTokenSource = null;
_adapter?.Dispose();
_adapter = null;
}
public void Dispose()
{
_backgroundCancellationTokenSource?.Cancel(false);
_backgroundCancellationTokenSource?.Dispose();
_backgroundCancellationTokenSource = null;
_adapter?.Dispose();
_adapter = null;
}
void Cleanup()
{
_backgroundCancellationTokenSource?.Cancel(false);
_backgroundCancellationTokenSource?.Dispose();
_backgroundCancellationTokenSource = null;
_publishPacketReceiverQueue?.Dispose();
_publishPacketReceiverQueue = null;
_adapter?.Dispose();
}
async Task SafeDisconnect(CancellationToken cancellationToken)
{
try
{
await _adapter.DisconnectAsync(_options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error(exception, "Error while disconnecting.");
}
finally
{
_adapter.Dispose();
}
}
private void TryDisposeAdapter(IMqttChannelAdapter adapter)
{
if (adapter == null)
{
return;
}
try
{
adapter.ReadingPacketStarted -= OnAdapterReadingPacketStarted;
adapter.ReadingPacketCompleted -= OnAdapterReadingPacketCompleted;
adapter.Dispose();
}
catch (Exception exception)
{
_logger.Error(exception, "Error while disposing channel adapter.");
}
}
async Task Cleanup(IMqttChannelAdapter clientAdapter)
{
try
{
await clientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error(exception, "Error while disconnecting channel adapter.");
}
try
{
clientAdapter.Dispose();
}
catch (Exception exception)
{
_logger.Error(exception, "Error while disposing channel adapter.");
}
}
private async Task RunSession(IMqttChannelAdapter clientAdapter, CancellationToken cancellationToken)
{
var clientId = string.Empty;
var wasCleanDisconnect = false;
try
{
var firstPacket = await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
if (firstPacket == null)
{
return;
}
if (!(firstPacket is MqttConnectPacket connectPacket))
{
throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
}
clientId = connectPacket.ClientId;
// Switch to the required protocol version before sending any response.
clientAdapter.PacketSerializer.ProtocolVersion = connectPacket.ProtocolVersion;
var connectReturnCode = ValidateConnection(connectPacket, clientAdapter);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await clientAdapter.SendPacketAsync(
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
},
cancellationToken).ConfigureAwait(false);
return;
}
var result = PrepareClientSession(connectPacket);
var clientSession = result.Session;
await clientAdapter.SendPacketAsync(
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = result.IsExistingSession
},
cancellationToken).ConfigureAwait(false);
Server.OnClientConnected(clientId);
wasCleanDisconnect = await clientSession.RunAsync(connectPacket, clientAdapter).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
finally
{
try
{
await clientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false);
clientAdapter.Dispose();
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
if (!_options.EnablePersistentSessions)
{
DeleteSession(clientId);
}
Server.OnClientDisconnected(clientId, wasCleanDisconnect);
}
}
public async Task RunSessionAsync(IMqttChannelAdapter clientAdapter, CancellationToken cancellationToken)
{
var clientId = string.Empty;
var wasCleanDisconnect = false;
MqttClientSession clientSession = null;
try
{
if (!(await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken)
.ConfigureAwait(false) is MqttConnectPacket connectPacket))
{
throw new MqttProtocolViolationException(
"The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
}
clientId = connectPacket.ClientId;
// Switch to the required protocol version before sending any response.
clientAdapter.PacketSerializer.ProtocolVersion = connectPacket.ProtocolVersion;
var connectReturnCode = ValidateConnection(connectPacket);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new[]
{
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
}
}).ConfigureAwait(false);
return;
}
var result = await GetOrCreateClientSessionAsync(connectPacket).ConfigureAwait(false);
clientSession = result.Session;
await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new[]
{
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = result.IsExistingSession
}
}).ConfigureAwait(false);
ClientConnectedCallback?.Invoke(new ConnectedMqttClient
{
ClientId = clientId,
ProtocolVersion = clientAdapter.PacketSerializer.ProtocolVersion
});
wasCleanDisconnect = await clientSession.RunAsync(connectPacket, clientAdapter).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error <MqttClientSessionsManager>(exception, exception.Message);
}
finally
{
try
{
await clientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout).ConfigureAwait(false);
clientAdapter.Dispose();
}
catch (Exception exception)
{
_logger.Error <MqttClientSessionsManager>(exception, exception.Message);
}
ClientDisconnectedCallback?.Invoke(new ConnectedMqttClient
{
ClientId = clientId,
ProtocolVersion = clientAdapter.PacketSerializer.ProtocolVersion,
PendingApplicationMessages = clientSession?.PendingMessagesQueue.Count ?? 0
},
wasCleanDisconnect);
}
}
public void Dispose()
{
_adapter?.Dispose();
}