public async Task <NimbusMessage> Peek()
{
var messageReceiver = await _queueManager.CreateDeadQueueMessageReceiver();
var Message = await messageReceiver.PeekAsync();
if (Message == null)
{
return(null);
}
var nimbusMessage = await _brokeredMessageFactory.BuildNimbusMessage(Message);
return(nimbusMessage);
}
protected override Task <NimbusMessage> Fetch(CancellationToken cancellationToken)
{
return(Task.Run(async() =>
{
await _receiveSemaphore.WaitAsync(_pollInterval, cancellationToken);
if (cancellationToken.IsCancellationRequested)
{
await _subscriptionClient.CloseAsync();
return null;
}
if (_messages.Count == 0)
{
return null;
}
var message = _messages.Take();
var nimbusMessage = await _brokeredMessageFactory.BuildNimbusMessage(message);
nimbusMessage.Properties[MessagePropertyKeys.RedeliveryToSubscriptionName] = _subscriptionName;
return nimbusMessage;
},
cancellationToken).ConfigureAwaitFalse());
}
protected override async Task <NimbusMessage> Fetch(CancellationToken cancellationToken)
{
try
{
using (var cancellationSemaphore = new SemaphoreSlim(0, int.MaxValue))
{
var subscriptionClient = await GetSubscriptionClient();
var receiveTask = subscriptionClient.ReceiveAsync(TimeSpan.FromSeconds(300)).ConfigureAwaitFalse();
var cancellationTask = Task.Run(async() => await CancellationTask(cancellationSemaphore, cancellationToken), cancellationToken).ConfigureAwaitFalse();
await Task.WhenAny(receiveTask, cancellationTask);
if (!receiveTask.IsCompleted)
{
return(null);
}
cancellationSemaphore.Release();
var brokeredMessage = await receiveTask;
if (brokeredMessage == null)
{
return(null);
}
var nimbusMessage = await _brokeredMessageFactory.BuildNimbusMessage(brokeredMessage);
nimbusMessage.Properties[MessagePropertyKeys.RedeliveryToSubscriptionName] = _subscriptionName;
return(nimbusMessage);
}
}
catch (MessagingEntityNotFoundException exc)
{
_logger.Error(exc, "The referenced topic subscription {TopicPath}/{SubscriptionName} no longer exists", _topicPath, _subscriptionName);
await _queueManager.MarkSubscriptionAsNonExistent(_topicPath, _subscriptionName);
DiscardSubscriptionClient();
throw;
}
catch (Exception exc)
{
_logger.Error(exc, "Messaging operation failed. Discarding message receiver.");
DiscardSubscriptionClient();
throw;
}
}
protected override async Task <NimbusMessage> Fetch(CancellationToken cancellationToken)
{
try
{
using (var cancellationSemaphore = new SemaphoreSlim(0, int.MaxValue))
{
var messageReceiver = await GetMessageReceiver();
var receiveTask = messageReceiver.ReceiveAsync(TimeSpan.FromSeconds(300)).ConfigureAwaitFalse();
var cancellationTask = Task.Run(async() => await CancellationTask(cancellationSemaphore, cancellationToken), cancellationToken).ConfigureAwaitFalse();
await Task.WhenAny(receiveTask, cancellationTask);
if (!receiveTask.IsCompleted)
{
return(null);
}
cancellationSemaphore.Release();
var brokeredMessage = await receiveTask;
if (brokeredMessage == null)
{
return(null);
}
var nimbusMessage = await _brokeredMessageFactory.BuildNimbusMessage(brokeredMessage);
return(nimbusMessage);
}
}
catch (MessagingEntityNotFoundException exc)
{
_logger.Error(exc, "The referenced queue {QueuePath} no longer exists", _queuePath);
await _queueManager.MarkQueueAsNonExistent(_queuePath);
DiscardMessageReceiver();
throw;
}
catch (Exception exc)
{
_logger.Error(exc, "Messaging operation failed. Discarding message receiver.");
DiscardMessageReceiver();
throw;
}
}