public void Publish(Topic topic, string message)
{
TopicState topicState;
if (topics.TryGetValue(topic, out topicState))
{
topicState.Publish(message);
}
}
public void Subscribe(string client, Topic topic, Action<Topic, string> handler)
{
var clientState = clients.GetOrAdd(client, _ => new ClientState(client));
var topicState = topics.GetOrAdd(topic, _ => new TopicState(topic));
lock (syncRoot)
{
topics[topic].Add(client, handler);
}
}
public IEnumerable<string> GetClientsForTopic(Topic topic)
{
if (!topics.ContainsKey(topic))
return new HashSet<string>();
lock (syncRoot)
{
return topics[topic].Clients;
}
}
public void Unsubscribe(string clientId, Topic topic)
{
TopicState topicState;
if (topics.TryGetValue(topic, out topicState))
{
lock (syncRoot)
{
topicState.Remove(clientId);
/* This is the last subscriber on this topic, remove the topic. */
if (topicState.Clients.Count() == 0)
topics.TryRemove(topic, out topicState);
if (topicState.Clients.Count() != 0)
throw new InvalidOperationException("Subscribed topic was removed.");
}
}
}
public TopicState(Topic topic)
{
this.topic = topic;
clients = new Dictionary<string, Action<Topic, string>>(StringComparer.OrdinalIgnoreCase);
}
