Registry
@see
http://dubbo.io/User+Guide-zh.htm#UserGuide-zh-Multicast%E6%B3%A8%E5%86%8C%E4%B8%AD%E5%BF%83
https://my.oschina.net/pingpangkuangmo/blog/515673
http://www.cnblogs.com/ghj1976/p/5328376.html
http://blog.csdn.net/quhongwei_zhanqiu/article/details/41683143
AbstractRegistry
registered -> 注册的URL
private final Set
subscribed -> 订阅的URL，当订阅成功时一般都需要通知订阅方，所以这里存储的是 订阅URL - 订阅监听
private final ConcurrentMap
notified -> 已通知的订阅，订阅URL-
private final ConcurrentMap
以上这些URL指的都是当前服务端/客服端，并不是整个注册中心
public void register(URL url) {
// ...
registered.add(url);
}
public void subscribe(URL url, NotifyListener listener) {
// ...
Set
subscribed.putIfAbsent(url, new ConcurrentHashSet
listeners = subscribed.get(url);
}
listeners.add(listener);
}
MulticastRegistry
@see
http://dubbo.io/User+Guide-zh.htm#UserGuide-zh-Multicast%E6%B3%A8%E5%86%8C%E4%B8%AD%E5%BF%83
http://www.cnblogs.com/ghj1976/p/5328376.html
http://www.cnblogs.com/ghj1976/p/5276452.html
1、提供方启动时广播自己的地址。
2、消费方启动时广播订阅请求。
3、提供方收到订阅请求时，单播自己的地址给订阅者，如果设置了unicast=false，则广播给订阅者。
4、消费方收到提供方地址时，连接该地址进行RPC调用。
//已接收的订阅：key:订阅url - value:提供服务的url集合
private final ConcurrentMap> received = new ConcurrentHashMap>();
//注册完成后置操作//遍历已订阅的urls，判断刚注册完成的url是否匹配，若匹配则说明订阅的url已到达，添加至received，并且获取订阅监听，通知监听完成相关后续操作//当注册成功时触发,有两处：
1、当前端(服务端或客户端)注册完成 时
2、其他端注册完成，并发送广/单播通知到当前端，通过DubboMutilcastRegistryReceiver的receive方法接收到时
protected void registered(URL url) { for (Map.Entry> entry : getSubscribed().entrySet()) { URL key = entry.getKey(); if (UrlUtils.isMatch(key, url)) { Seturls = received.get(key); if (urls == null) { received.putIfAbsent(key, new ConcurrentHashSet()); urls = received.get(key); } urls.add(url); List list = toList(urls);
for (NotifyListener listener : entry.getValue()) {
notify(key, listener, list);
synchronized (listener) {
listener.notify();
}
}
}
}
}