private ushort GetProperPrefetchSize(IPrioritySubscriptionOption subscriptionOption, uint priority)
{
var prefetchSize = subscriptionOption.QueuePrefetchSizeSelector != null
? subscriptionOption.QueuePrefetchSizeSelector(priority)
: subscriptionOption.QueuePrefetchSize;
if (prefetchSize <= 0)
{
prefetchSize = Global.PreFetchSize;
}
if (prefetchSize > ushort.MaxValue)
{
_watcher.WarnFormat("The prefetch size is too high {0}, the queue will prefetch the maximum {1} msgs", prefetchSize, ushort.MaxValue);
}
return((ushort)Math.Min(ushort.MaxValue, prefetchSize));
}
private string GetPriorityQueueName <T>(IPrioritySubscriptionOption subscriptionOption, uint priority)
{
return((subscriptionOption.RouteFinder ?? _routeFinder).FindQueueName <T>(subscriptionOption.SubscriptionName) +
(subscriptionOption.QueueSuffixNameConvention ?? PriorityQueuesRabbitSetup.GlobalPriorityQueueSuffix).Get(typeof(T), priority));
}
private CompositeSubscription CreateSubscription <T>(IPrioritySubscriptionOption subscriptionOption, Func <IModel, string, IBasicConsumer> createConsumer)
{
var comparer = TryGetComparer(subscriptionOption.ComparerType);
var compositeSubscription = new CompositeSubscription();
uint maxSize = 0;
for (uint level = 0; level <= subscriptionOption.MaxPriorityLevel; level++)
{
maxSize += GetProperPrefetchSize(subscriptionOption, level);
}
var priorityQueue = new InMemoryPriorityQueue <GenericPriorityMessage <BasicDeliverEventArgs> >(maxSize, comparer);
var sharedSemaphore = string.Format("{0}{1}", subscriptionOption.SubscriptionName, Guid.NewGuid());
for (uint level = 0; level <= subscriptionOption.MaxPriorityLevel; level++)
{
var subscription = new Subscription {
SubscriptionName = subscriptionOption.SubscriptionName
};
uint priority = level;
var id = Guid.NewGuid();
Action subscriptionAction = () =>
{
subscription.QueueName = GetPriorityQueueName <T>(subscriptionOption, priority);
if (string.IsNullOrEmpty(subscription.ConsumerTag))
{
// Keep the key here because it's used for the key indexes of internal cache
subscription.ConsumerTag = string.Format("{0}-{1}", subscriptionOption.SubscriptionName, Guid.NewGuid());
}
var channel = _connection.CreateChannel();
channel.ModelShutdown += (c, reason) =>
{
RaiseConsumerDisconnectedEvent(subscription);
TryReconnect(c, id, reason);
};
var prefetchSize = GetProperPrefetchSize(subscriptionOption, priority);
channel.BasicQos(0, prefetchSize, false);
_createdChannels.Add(channel);
var consumer = createConsumer(channel, subscription.ConsumerTag);
var priorityConsumer = consumer as PriorityBurrowConsumer;
if (priorityConsumer == null)
{
throw new NotSupportedException(string.Format("Expected PriorityBurrowConsumer but was {0}", consumer == null ? "NULL" : consumer.GetType().Name));
}
priorityConsumer.Init(priorityQueue, compositeSubscription, priority, sharedSemaphore);
priorityConsumer.ConsumerTag = subscription.ConsumerTag;
subscription.SetChannel(channel);
//NOTE: The message will still be on the Unacknowledged list until it's processed and the method
// DoAck is call.
channel.BasicConsume(subscription.QueueName,
false /* noAck, must be false */,
subscription.ConsumerTag, priorityConsumer);
_watcher.InfoFormat("Subscribed to: {0} with subscriptionName: {1}",
subscription.QueueName,
subscription.SubscriptionName);
priorityConsumer.Ready();
};
_subscribeActions[id] = subscriptionAction;
TrySubscribe(subscriptionAction);
compositeSubscription.AddSubscription(subscription);
}
return(compositeSubscription);
}
