public async Task ExecuteAsync(string clientId, IPacket input, IMqttChannel <IPacket> channel)
{
if (input.Type != MqttPacketType.Subscribe)
{
return;
}
Subscribe subscribe = input as Subscribe;
ClientSession session = _sessionRepository.Read(clientId);
if (session == null)
{
throw new MqttException(ServerProperties.SessionRepository_ClientSessionNotFound(clientId));
}
List <SubscribeReturnCode> returnCodes = new List <SubscribeReturnCode>();
foreach (Subscription subscription in subscribe.Subscriptions)
{
try
{
if (!_topicEvaluator.IsValidTopicFilter(subscription.TopicFilter))
{
_tracer.Error(ServerProperties.ServerSubscribeFlow_InvalidTopicSubscription(subscription.TopicFilter, clientId));
returnCodes.Add(SubscribeReturnCode.Failure);
continue;
}
ClientSubscription clientSubscription = session
.GetSubscriptions()
.FirstOrDefault(s => s.TopicFilter == subscription.TopicFilter);
if (clientSubscription != null)
{
clientSubscription.MaximumQualityOfService = subscription.MaximumQualityOfService;
}
else
{
clientSubscription = new ClientSubscription
{
ClientId = clientId,
TopicFilter = subscription.TopicFilter,
MaximumQualityOfService = subscription.MaximumQualityOfService
};
session.AddSubscription(clientSubscription);
}
await SendRetainedMessagesAsync(clientSubscription, channel);
MqttQualityOfService supportedQos = _configuration.GetSupportedQos(subscription.MaximumQualityOfService);
SubscribeReturnCode returnCode = supportedQos.ToReturnCode();
returnCodes.Add(returnCode);
}
catch (RepositoryException repoEx)
{
_tracer.Error(repoEx, ServerProperties.ServerSubscribeFlow_ErrorOnSubscription(clientId, subscription.TopicFilter));
returnCodes.Add(SubscribeReturnCode.Failure);
}
}
_sessionRepository.Update(session);
await channel.SendAsync(new SubscribeAck( subscribe.PacketId, returnCodes.ToArray()));
}