void RemoveSubscription(MessageSubscription sub)
{
lock (_gate)
{
_subscriptions = _subscriptions.Remove(sub);
if (_subscriptions.Count == 0)
{
OnLastSubscriptionRemoved();
}
}
}
public IDisposable Subscribe(IObserver <IReadOnlyMessage> observer)
{
var sub = new MessageSubscription(s => RemoveSubscription(s), observer);
lock (_gate)
{
_subscriptions = _subscriptions.Add(sub);
if (_subscriptions.Count == 1)
{
OnFirstSubscriptionAdded();
}
}
return(sub);
}
