Class inheritance relationship:
- AbstractDirectory implements the Directory#list(Invocation) interface
- RegistryDirectory inherits the AbstractDirectory class && implements NotifyListener#notify(List) to monitor notifications
AbstractDirectory gets the Invoker list
public List<Invoker<T>> list(Invocation invocation) throws RpcException {
if (destroyed) {
throw new RpcException("Directory already destroyed .url: " + getUrl());
}
// 通过子类获取invoker列表
List<Invoker<T>> invokers = doList(invocation);
// 获取路由信息
List<Router> localRouters = this.routers; // local reference
if (localRouters != null && !localRouters.isEmpty()) {
for (Router router : localRouters) {
try {
if (router.getUrl() == null || router.getUrl().getParameter(Constants.RUNTIME_KEY, false)) {
// 对不符合路由规则的invokers进行过滤
invokers = router.route(invokers, getConsumerUrl(), invocation);
}
} catch (Throwable t) {
logger.error("Failed to execute router: " + getUrl() + ", cause: " + t.getMessage(), t);
}
}
}
return invokers;
}
Notify the update of node information such as configurators, routers, and invokers.
// urls：需变更的URL列表
// RegistryDirectory#notify(List<URL> urls)
public synchronized void notify(List<URL> urls) {
List<URL> invokerUrls = new ArrayList<URL>();
List<URL> routerUrls = new ArrayList<URL>();
List<URL> configuratorUrls = new ArrayList<URL>();
for (URL url : urls) {
String protocol = url.getProtocol();
String category = url.getParameter(Constants.CATEGORY_KEY, Constants.DEFAULT_CATEGORY);
if (Constants.ROUTERS_CATEGORY.equals(category)
|| Constants.ROUTE_PROTOCOL.equals(protocol)) {
routerUrls.add(url);
} else if (Constants.CONFIGURATORS_CATEGORY.equals(category)
|| Constants.OVERRIDE_PROTOCOL.equals(protocol)) {
configuratorUrls.add(url);
} else if (Constants.PROVIDERS_CATEGORY.equals(category)) {
invokerUrls.add(url);
} else {
logger.warn("Unsupported category " + category + " in notified url: " + url + " from registry " + getUrl().getAddress() + " to consumer " + NetUtils.getLocalHost());
}
}
// configurators
if (configuratorUrls != null && !configuratorUrls.isEmpty()) {
this.configurators = toConfigurators(configuratorUrls);
}
// routers
if (routerUrls != null && !routerUrls.isEmpty()) {
// 通过配置获取路由规则
// 后面详细解析
List<Router> routers = toRouters(routerUrls);
if (routers != null) {
// null - do nothing
setRouters(routers);
}
}
List<Configurator> localConfigurators = this.configurators; // local reference
// merge override parameters
this.overrideDirectoryUrl = directoryUrl;
if (localConfigurators != null && !localConfigurators.isEmpty()) {
for (Configurator configurator : localConfigurators) {
this.overrideDirectoryUrl = configurator.configure(overrideDirectoryUrl);
}
}
// providers
refreshInvoker(invokerUrls);
}
Refresh Invoker
// RegistryDirectory#refreshInvoker(List<URL> invokerUrls)
private void refreshInvoker(List<URL> invokerUrls) {
// invokerUrls.get(0).getProtocol() == 'empty'
if (invokerUrls != null && invokerUrls.size() == 1 && invokerUrls.get(0) != null
&& Constants.EMPTY_PROTOCOL.equals(invokerUrls.get(0).getProtocol())) {
this.forbidden = true; // Forbid to access
this.methodInvokerMap = null; // Set the method invoker map to null
destroyAllInvokers(); // Close all invokers
} else {
this.forbidden = false; // Allow to access
Map<String, Invoker<T>> oldUrlInvokerMap = this.urlInvokerMap; // local reference
if (invokerUrls.isEmpty() && this.cachedInvokerUrls != null) {
invokerUrls.addAll(this.cachedInvokerUrls);
} else {
this.cachedInvokerUrls = new HashSet<URL>();
this.cachedInvokerUrls.addAll(invokerUrls);//Cached invoker urls, convenient for comparison
}
if (invokerUrls.isEmpty()) {
return;
}
Map<String, Invoker<T>> newUrlInvokerMap = toInvokers(invokerUrls);// Translate url list to Invoker map
Map<String, List<Invoker<T>>> newMethodInvokerMap = toMethodInvokers(newUrlInvokerMap); // Change method name to map Invoker Map
// state change
// If the calculation is wrong, it is not processed.
if (newUrlInvokerMap == null || newUrlInvokerMap.size() == 0) {
logger.error(new IllegalStateException("urls to invokers error .invokerUrls.size :" + invokerUrls.size() + ", invoker.size :0. urls :" + invokerUrls.toString()));
return;
}
this.methodInvokerMap = multiGroup ? toMergeMethodInvokerMap(newMethodInvokerMap) : newMethodInvokerMap;
this.urlInvokerMap = newUrlInvokerMap;
try {
destroyUnusedInvokers(oldUrlInvokerMap, newUrlInvokerMap); // Close the unused Invoker
} catch (Exception e) {
logger.warn("destroyUnusedInvokers error. ", e);
}
}
}
Generate routing list List
private List<Router> toRouters(List<URL> urls) {
List<Router> routers = new ArrayList<Router>();
if (urls == null || urls.isEmpty()) {
return routers;
}
if (urls != null && !urls.isEmpty()) {
for (URL url : urls) {
// url.protocol == 'empty'不处理
if (Constants.EMPTY_PROTOCOL.equals(url.getProtocol())) {
continue;
}
// 从url中获取参数router
// 取值有"script"/"file"/"condition"
String routerType = url.getParameter(Constants.ROUTER_KEY);
if (routerType != null && routerType.length() > 0) {
url = url.setProtocol(routerType);
}
try {
// RouterFactory是一个@SPI类，getRouter(URL)方法是@Adaptive("protocol")修饰的，所以通过url.protocol决定实现类
// TODO 为什么Router不是直接通过@SPI来注入呢？而是要加一个工厂呢？
Router router = routerFactory.getRouter(url);
if (!routers.contains(router))
routers.add(router);
} catch (Throwable t) {
logger.error("convert router url to router error, url: " + url, t);
}
}
}
return routers;
}