private void ClientsForSessionThread()
{
while (isRunning)
{
try
{
string clientId = this.clientsForSession.Take();
MqttBrokerSession session = MqttSessionManager.GetSession(clientId);
MqttMsgPublish outgoingMsg;
while (session.OutgoingMessages.TryDequeue(out outgoingMsg))
{
var query = from s in session.Subscriptions
where (new Regex(s.Topic)).IsMatch(outgoingMsg.Topic)
// check for topics based also on wildcard with regex
select s;
MqttSubscription subscription = query.FirstOrDefault();
if (subscription != null)
{
var qosLevel = (subscription.QosLevel < outgoingMsg.QosLevel) ? subscription.QosLevel : outgoingMsg.QosLevel;
MqttMessageToClientConnectionManager.Publish(subscription.ClientConnection, outgoingMsg.Topic, outgoingMsg.Message, qosLevel, outgoingMsg.Retain);
}
}
}
catch (Exception exception)
{
logger.LogException(this, exception);
}
}
}
public void OnConnectionClosed(MqttClientConnection clientConnection)
{
// if client is connected
MqttClientConnection connectedClient;
if (clientConnection.IsConnected && MqttBroker.TryRemoveClientConnection(clientConnection.ClientId, out connectedClient))
{
// client has a will message
if (clientConnection.WillFlag)
{
// create the will PUBLISH message
MqttMsgPublish publish = new MqttMsgPublish(clientConnection.WillTopic, Encoding.UTF8.GetBytes(clientConnection.WillMessage), false, clientConnection.WillQosLevel, false);
// publish message through publisher manager
this.publishManager.Publish(publish);
}
// if not clean session
if (!clientConnection.CleanSession)
{
List <MqttSubscription> subscriptions = clientConnection.Subscriptions.Values.ToList();
if (subscriptions.Count > 0)
{
MqttSessionManager.SaveSession(clientConnection.ClientId, clientConnection.Session, subscriptions);
// TODO : persist client session if broker close
}
}
foreach (var topic in clientConnection.Subscriptions.Keys)
{
// delete client from runtime subscription
MqttSubscriberManager.Unsubscribe(topic, clientConnection);
}
// close the client
CloseClientConnection(clientConnection);
clientConnectionManager.ReturnConnection(clientConnection);
Interlocked.Decrement(ref numberOfConnectedClients);
}
}
private void SessionPublishThread()
{
while (this.isRunning)
{
try
{
var publish = (MqttMsgPublish)this.sessionPublishQueue.Take();
if (publish != null)
{
// get all sessions
List <MqttBrokerSession> sessions = MqttSessionManager.GetSessions();
if ((sessions != null) && (sessions.Count > 0))
{
foreach (MqttBrokerSession session in sessions)
{
var query = from s in session.Subscriptions
where (new Regex(s.Topic)).IsMatch(publish.Topic)
select s;
MqttSubscriptionComparer comparer = new MqttSubscriptionComparer(MqttSubscriptionComparer.MqttSubscriptionComparerType.OnClientId);
// consider only session active for client disconnected (not online)
if (session.ClientConnection == null)
{
foreach (MqttSubscription subscription in query.Distinct(comparer))
{
// save PUBLISH message for client disconnected (not online)
session.OutgoingMessages.Enqueue(publish);
}
}
}
}
}
}
catch (Exception exception)
{
logger.LogException(this, exception);
}
}
}
public void OnMqttMsgConnected(MqttClientConnection clientConnection, MqttMsgConnect message)
{
clientConnection.ProtocolVersion = (MqttProtocolVersion)message.ProtocolVersion;
// verify message to determine CONNACK message return code to the client
byte returnCode = MqttConnectVerify(message);
// [v3.1.1] if client id is zero length, the broker assigns a unique identifier to it
var clientId = (message.ClientId.Length != 0) ? message.ClientId : Guid.NewGuid().ToString();
// connection "could" be accepted
if (returnCode == MqttMsgConnack.CONN_ACCEPTED)
{
// check if there is a client already connected with same client Id
MqttClientConnection clientConnectionConnected = MqttBroker.GetClientConnection(clientId);
// force connection close to the existing client (MQTT protocol)
if (clientConnectionConnected != null)
{
OnConnectionClosed(clientConnectionConnected);
}
// add client to the collection
MqttBroker.TryAddClientConnection(clientId, clientConnection);
Interlocked.Increment(ref numberOfConnectedClients);
}
// connection accepted, load (if exists) client session
if (returnCode == MqttMsgConnack.CONN_ACCEPTED)
{
// check if not clean session and try to recovery a session
if (!message.CleanSession)
{
// create session for the client
MqttClientSession clientSession = new MqttClientSession(clientId);
// get session for the connected client
MqttBrokerSession session = MqttSessionManager.GetSession(clientId);
// [v3.1.1] session present flag
bool sessionPresent = false;
// set inflight queue into the client session
if (session != null)
{
clientSession.InflightMessages = session.InflightMessages;
// [v3.1.1] session present flag
if (clientConnection.ProtocolVersion == MqttProtocolVersion.Version_3_1_1)
{
sessionPresent = true;
}
}
// send CONNACK message to the client
MqttOutgoingMessageManager.Connack(clientConnection, message, returnCode, clientId, sessionPresent);
// load/inject session to the client
clientConnection.LoadSession(clientSession);
if (session != null)
{
// set reference to connected client into the session
session.ClientConnection = clientConnection;
// there are saved subscriptions
if (session.Subscriptions != null)
{
// register all subscriptions for the connected client
foreach (MqttSubscription subscription in session.Subscriptions)
{
MqttSubscriberManager.Subscribe(
subscription.Topic,
subscription.QosLevel,
clientConnection);
// publish retained message on the current subscription
RetainedMessageManager.PublishRetaind(subscription.Topic, clientConnection);
}
}
// there are saved outgoing messages
if (session.OutgoingMessages.Count > 0)
{
// publish outgoing messages for the session
this.publishManager.PublishSession(session.ClientId);
}
}
}
// requested clean session
else
{
// send CONNACK message to the client
MqttOutgoingMessageManager.Connack(clientConnection, message, returnCode, clientId, false);
MqttSessionManager.ClearSession(clientId);
}
}
else
{
// send CONNACK message to the client
MqttOutgoingMessageManager.Connack(clientConnection, message, returnCode, clientId, false);
}
}