public async Task <TopicDescription> Create(string topicPath, INamespaceManager namespaceManager)
{
var topicDescription = topicDescriptionFactory(topicPath, settings);
try
{
if (!await ExistsAsync(topicPath, namespaceManager).ConfigureAwait(false))
{
await namespaceManager.CreateTopic(topicDescription).ConfigureAwait(false);
logger.InfoFormat("Topic '{0}' in namespace '{1}' created.", topicDescription.Path, namespaceManager.Address);
var key = GenerateTopicKey(topicPath, namespaceManager);
await rememberExistence.AddOrUpdate(key, notFoundTopicPath => Task.FromResult(true), (updateTopicPath, previousValue) => Task.FromResult(true)).ConfigureAwait(false);
}
else
{
logger.InfoFormat("Topic '{0}' in namespace '{1}' already exists, skipping creation.", topicDescription.Path, namespaceManager.Address);
logger.InfoFormat("Checking if topic '{0}' in namespace '{1}' needs to be updated.", topicDescription.Path, namespaceManager.Address);
var existingTopicDescription = await namespaceManager.GetTopic(topicDescription.Path).ConfigureAwait(false);
if (MembersAreNotEqual(existingTopicDescription, topicDescription))
{
OverrideImmutableMembers(existingTopicDescription, topicDescription);
logger.InfoFormat("Updating topic '{0}' in namespace '{1}' with new description.", topicDescription.Path, namespaceManager.Address);
await namespaceManager.UpdateTopic(topicDescription).ConfigureAwait(false);
}
}
}
catch (MessagingEntityAlreadyExistsException)
{
// the topic already exists or another node beat us to it, which is ok
logger.InfoFormat("Topic '{0}' in namespace '{1}' already exists, another node probably beat us to it.", topicDescription.Path, namespaceManager.Address);
}
catch (TimeoutException)
{
logger.InfoFormat("Timeout occurred on topic creation for '{0}' in namespace '{1}' going to validate if it doesn't exist.", topicDescription.Path, namespaceManager.Address);
// there is a chance that the timeout occurred, but the topic was still created, check again
if (!await ExistsAsync(topicDescription.Path, namespaceManager, removeCacheEntry: true).ConfigureAwait(false))
{
throw;
}
logger.InfoFormat("Looks like topic '{0}' in namespace '{1}' exists anyway.", topicDescription.Path, namespaceManager.Address);
}
catch (MessagingException ex)
{
var loggedMessage = string.Format("{1} {2} occurred on topic creation '{0}' in namespace {3}.", topicDescription.Path, (ex.IsTransient ? "Transient" : "Non transient"), ex.GetType().Name, namespaceManager.Address);
if (!ex.IsTransient)
{
logger.Fatal(loggedMessage, ex);
throw;
}
logger.Info(loggedMessage, ex);
}
return(topicDescription);
}
