public async Task SubscribeAsync(string topic, MqttQualityOfServiceLevel qos, IMqttMessageListener listener)
{
CheckOpen();
// Subscribe to the topic
// Todo: Shall we skip if similar subscription already exist?
await _connection.SubscribeAsync(topic, qos);
lock (_lock)
{
var filter = topic.IndexOf("*") < 0;
// Add subscription to the list
var subscription = new MqttSubscription
{
Topic = topic,
Listener = listener,
Filter = filter,
Qos = qos
};
_subscriptions.Add(subscription);
}
}
public async Task UnsubscribeAsync(string topic, IMqttMessageListener listener)
{
CheckOpen();
MqttSubscription deletedSubscription = null;
var hasMoreSubscriptions = false;
lock (_lock)
{
// Find subscription
for (var index = 0; index < _subscriptions.Count; index++)
{
var subscription = _subscriptions[index];
if (subscription.Topic == topic && subscription.Listener == listener)
{
deletedSubscription = subscription;
_subscriptions.RemoveAt(index);
break;
}
}
// Find subscriptions to the same topic
foreach (var subscription in _subscriptions)
{
if (subscription.Topic == topic)
{
hasMoreSubscriptions = true;
}
}
}
// Unsubscribe if there are no more subscriptions
if (!hasMoreSubscriptions)
{
await _connection.UnsubscribeAsync(topic);
}
}
