private Lazy <ServiceBusClient> CreateSessionClient()
{
return(new Lazy <ServiceBusClient>(() => _messagingProvider.CreateSessionClient(_serviceBusAccount.ConnectionString)));
}
internal void StartMessageBatchReceiver(CancellationToken cancellationToken)
{
SessionClient sessionClient = null;
IMessageReceiver receiver = null;
if (_isSessionsEnabled)
{
sessionClient = _messagingProvider.CreateSessionClient(_entityPath, _serviceBusAccount.ConnectionString);
}
else
{
receiver = Receiver;
}
Task.Run(async() =>
{
while (true)
{
try
{
if (!_started || cancellationToken.IsCancellationRequested)
{
return;
}
if (_isSessionsEnabled)
{
try
{
receiver = await sessionClient.AcceptMessageSessionAsync();
}
catch (ServiceBusTimeoutException)
{
// it's expected if the entity is empty, try next time
continue;
}
}
IList <Message> messages = await receiver.ReceiveAsync(_serviceBusOptions.BatchOptions.MaxMessageCount, _serviceBusOptions.BatchOptions.OperationTimeout);
if (messages != null)
{
Message[] messagesArray = messages.ToArray();
ServiceBusTriggerInput input = ServiceBusTriggerInput.CreateBatch(messagesArray);
input.MessageReceiver = receiver;
FunctionResult result = await _triggerExecutor.TryExecuteAsync(input.GetTriggerFunctionData(), cancellationToken);
if (cancellationToken.IsCancellationRequested)
{
return;
}
// Complete batch of messages only if the execution was successful
if (_serviceBusOptions.BatchOptions.AutoComplete && _started)
{
if (result.Succeeded)
{
await receiver.CompleteAsync(messagesArray.Select(x => x.SystemProperties.LockToken));
}
else
{
// Delivery count is not incremented if
// Session is accepted, the messages within the session are not completed (even if they are locked), and the session is closed
// https://docs.microsoft.com/en-us/azure/service-bus-messaging/message-sessions#impact-of-delivery-count
if (_isSessionsEnabled)
{
List <Task> abandonTasks = new List <Task>();
foreach (var lockTocken in messagesArray.Select(x => x.SystemProperties.LockToken))
{
abandonTasks.Add(receiver.AbandonAsync(lockTocken));
}
await Task.WhenAll(abandonTasks);
}
}
}
// Close the session and release the session lock
if (_isSessionsEnabled)
{
await receiver.CloseAsync();
}
}
}
catch (ObjectDisposedException)
{
// Ignore as we are stopping the host
}
catch (Exception ex)
{
// Log another exception
_logger.LogError($"An unhandled exception occurred in the message batch receive loop: {ex.ToString()}");
}
}
}, cancellationToken);
}