private void TryPublishQueuedMessage(ManagedMqttApplicationMessage message)
{
Exception transmitException = null;
try
{
_mqttClient.PublishAsync(message.ApplicationMessage).GetAwaiter().GetResult();
_storageManager?.RemoveAsync(message).GetAwaiter().GetResult();
}
catch (MqttCommunicationException exception)
{
transmitException = exception;
_logger.Warning(exception, $"Publishing application ({message.Id}) message failed.");
if (message.ApplicationMessage.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
{
_messageQueue.Add(message);
}
}
catch (Exception exception)
{
transmitException = exception;
_logger.Error(exception, $"Unhandled exception while publishing application message ({message.Id}).");
}
finally
{
ApplicationMessageProcessed?.Invoke(this, new ApplicationMessageProcessedEventArgs(message, transmitException));
}
}
public async Task PublishAsync(ManagedMqttApplicationMessage applicationMessage)
{
if (applicationMessage == null)
{
throw new ArgumentNullException(nameof(applicationMessage));
}
ManagedMqttApplicationMessage removedMessage = null;
lock (_messageQueue)
{
if (_messageQueue.Count >= Options.MaxPendingMessages)
{
if (Options.PendingMessagesOverflowStrategy == MqttPendingMessagesOverflowStrategy.DropNewMessage)
{
_logger.Verbose("Skipping publish of new application message because internal queue is full.");
ApplicationMessageSkipped?.Invoke(this, new ApplicationMessageSkippedEventArgs(applicationMessage));
return;
}
if (Options.PendingMessagesOverflowStrategy == MqttPendingMessagesOverflowStrategy.DropOldestQueuedMessage)
{
removedMessage = _messageQueue.RemoveFirst();
_logger.Verbose("Removed oldest application message from internal queue because it is full.");
ApplicationMessageSkipped?.Invoke(this, new ApplicationMessageSkippedEventArgs(removedMessage));
}
}
_messageQueue.Enqueue(applicationMessage);
}
if (_storageManager != null)
{
if (removedMessage != null)
{
await _storageManager.RemoveAsync(removedMessage).ConfigureAwait(false);
}
await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
}
}