async Task <bool> ExistsAsync(string topicPath, INamespaceManager namespaceClient, bool removeCacheEntry = false)
{
var key = GenerateTopicKey(topicPath, namespaceClient);
logger.InfoFormat("Checking existence cache for '{0}' in namespace '{1}'.", topicPath, namespaceClient.Address);
if (removeCacheEntry)
{
Task <bool> dummy;
rememberExistence.TryRemove(key, out dummy);
}
var exists = await rememberExistence.GetOrAdd(key, notFoundTopicPath =>
{
logger.InfoFormat("Checking namespace for existence of the topic '{0}' in namespace '{1}'.", topicPath, namespaceClient.Address);
return(namespaceClient.TopicExists(topicPath));
}).ConfigureAwait(false);
logger.InfoFormat("Determined, from cache, that the topic '{0}' in namespace '{2}' {1}.", topicPath, exists ? "exists" : "does not exist", namespaceClient.Address);
return(exists);
}
private void EnsureMessagingEntityExists(MessageTypeMessagingEntityMappingDetails mappingDetails, IEnumerable <MessageTypeMessagingEntityMappingDetails> allMessageTypePathMappings)
{
MessagingEntityCreationOptions creationOptions = mappingDetails.CreationOptions;
if (creationOptions != MessagingEntityCreationOptions.None
&&
!_verifiedExistingMessagingEntities.Contains(mappingDetails))
{
Func <bool> exists;
Action create;
Action delete;
string path = mappingDetails.Path;
switch (mappingDetails.MessagingEntityType)
{
case MessagingEntityType.Queue:
exists = () => _namespaceManager.QueueExists(path);
create = () => _namespaceManager.CreateQueue(path);
delete = () => _namespaceManager.DeleteQueue(path);
break;
case MessagingEntityType.Topic:
exists = () => _namespaceManager.TopicExists(path);
create = () => _namespaceManager.CreateTopic(path);
delete = () => _namespaceManager.DeleteTopic(path);
break;
case MessagingEntityType.Subscription:
string[] parts = path.Split('/');
string topicPath = parts[0];
string subscriptionName = parts[2];
exists = () => _namespaceManager.SubscriptionExists(topicPath, subscriptionName);
create = () =>
{
MessageTypeMessagingEntityMappingDetails topicMessageTypePathMapping = allMessageTypePathMappings.FirstOrDefault(mtpmd => mtpmd.MessagingEntityType == MessagingEntityType.Topic && mtpmd.Path == topicPath);
if (topicMessageTypePathMapping == null)
{
topicMessageTypePathMapping = new MessageTypeMessagingEntityMappingDetails(mappingDetails.MessageType, topicPath, MessagingEntityType.Topic, MessagingEntityCreationOptions.VerifyAlreadyExists);
}
EnsureMessagingEntityExists(topicMessageTypePathMapping, allMessageTypePathMappings);
_namespaceManager.CreateSubscription(topicPath, subscriptionName);
};
delete = () => _namespaceManager.DeleteSubscription(topicPath, subscriptionName);
break;
default:
throw new NotSupportedException(string.Format("Unsupported messaging entity type, {0}, requested for creation (path {1}).", mappingDetails.MessagingEntityType, mappingDetails.Path));
}
bool alreadyExists = exists();
if (alreadyExists)
{
if ((creationOptions & MessagingEntityCreationOptions.CreateAsTemporary) != 0)
{
if ((creationOptions & MessagingEntityCreationOptions.RecreateExistingTemporary) == 0)
{
throw new MessagingEntityAlreadyExistsException(mappingDetails.Path, mappingDetails.MessagingEntityType);
}
try
{
delete();
alreadyExists = false;
}
catch (UnauthorizedAccessException exception)
{
throw new UnauthorizedAccessException(string.Format("Unable to delete temporary messaging that already exists at path \"{0}\" due to insufficient access. Make sure the policy being used has 'Manage' permission for the namespace.", mappingDetails.Path), exception);
}
}
}
if (!alreadyExists)
{
if ((creationOptions & (MessagingEntityCreationOptions.CreateIfDoesntExist | MessagingEntityCreationOptions.CreateAsTemporary)) == 0)
{
throw new MessagingEntityDoesNotAlreadyExistException(mappingDetails.Path, mappingDetails.MessagingEntityType);
}
try
{
create();
}
catch (UnauthorizedAccessException exception)
{
throw new UnauthorizedAccessException(string.Format("Unable to create messaging entity at path \"{0}\" due to insufficient access. Make sure the policy being used has 'Manage' permission for the namespace.", mappingDetails.Path), exception);
}
}
_verifiedExistingMessagingEntities.Add(mappingDetails);
}
}