private void ListenToQueue(QueueSubscription subscription)
{
using (var connection = _connectionFactory.CreateConnection())
{
using (var model = connection.CreateModel())
{
var consumer = new QueueingBasicConsumer(model);
model.ConfirmSelect(); //try publisher confirms
var queueName = subscription.SubscriptionData.Queue;
model.DeclareQueue(queueName, subscription.SubscriptionData.Args);
model.BasicQos(0, subscription.SubscriptionData.PrefetchCount, false);
model.BasicConsume(queueName, false, consumer);
subscription.OpenEvent.Set();
_logger.LogTrace("Subscription set up with Channel Hash {0}", model.GetHashCode());
while (subscription.KeepListening)
{
BasicDeliverEventArgs basicDeliverEventArgs = null;
if (!consumer.Queue.Dequeue((int)TimeSpan.FromSeconds(5).TotalMilliseconds, out basicDeliverEventArgs))
{
if (basicDeliverEventArgs != null)
{
throw new Exception("Could not get message within timeout - expected event args to be null");
}
continue;
}
var body = basicDeliverEventArgs.Body;
var headers = basicDeliverEventArgs.BasicProperties.Headers;
var message = new RabbitMessage
{
Id = Guid.NewGuid(),
RawMessage = body,
RawHeaders = headers.ToDictionary(kvp => kvp.Key, kvp => kvp.Value as byte[]),
Channel = model,
DeliveryTag = basicDeliverEventArgs.DeliveryTag,
ErrorHandler = _errorHandler,
};
try
{
subscription.MessageObserver.OnNext(message);
}
catch (Exception e)
{
_errorHandler.Error(message, e);
subscription.MessageObserver.OnError(e);
}
}
}
}
}
public async Task <object> SubscribeAsync(QueueSubscription subscription)
{
try
{
var taskCompletionSource = new TaskCompletionSource <object>();
Task.Run(() => { SubscribeToQueue(subscription, taskCompletionSource); });
return(taskCompletionSource.Task);
}
catch (Exception e)
{
_logger.LogError("Error initializing connection", e);
throw;
}
}
private void SubscribeToQueue(QueueSubscription subscription, TaskCompletionSource <object> taskCompletionSource)
{
try
{
ListenToQueue(subscription);
}
catch (EndOfStreamException eosE)
{
SubscribeToQueue(subscription, taskCompletionSource);
_logger.LogWarn("EndOfStreamException caught. Will try to reconnect...");
}
catch (Exception e)
{
_logger.LogError("Error in queue subscriber", e);
taskCompletionSource.SetException(e);
return;
}
finally
{
subscription.MessageObserver.OnCompleted();
}
taskCompletionSource.SetResult(null);
}