From 1bd06c1e99956482f38f67595fdd24550342fb4b Mon Sep 17 00:00:00 2001
From: "binbin.zhang" <bbz17640380550@163.com>
Date: Wed, 1 Dec 2021 14:49:53 +0800
Subject: [PATCH] nacos support UnRegister and  UnSubscribe (#1616)

---
 registry/nacos/listener.go | 20 +++++++++++-------
 registry/nacos/registry.go | 43 ++++++++++++++++++++++++++++++--------
 2 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/registry/nacos/listener.go b/registry/nacos/listener.go
index 67b9d1f162..e0cbe2eaa7 100644
--- a/registry/nacos/listener.go
+++ b/registry/nacos/listener.go
@@ -44,6 +44,12 @@ import (
 	"dubbo.apache.org/dubbo-go/v3/remoting"
 )
 
+var (
+	listenerCache sync.Map
+)
+
+type callback func(services []model.SubscribeService, err error)
+
 type nacosListener struct {
 	namingClient   *nacosClient.NacosNamingClient
 	listenURL      *common.URL
@@ -191,15 +197,15 @@ func (nl *nacosListener) startListen() error {
 	if nl.namingClient == nil {
 		return perrors.New("nacos naming namingClient stopped")
 	}
-	serviceName := getSubscribeName(nl.listenURL)
-	groupName := nl.regURL.GetParam(constant.RegistryGroupKey, defaultGroup)
-	nl.subscribeParam = &vo.SubscribeParam{
-		ServiceName:       serviceName,
-		SubscribeCallback: nl.Callback,
-		GroupName:         groupName,
+	nl.subscribeParam = createSubscribeParam(nl.listenURL, nl.regURL, nl.Callback)
+	if nl.subscribeParam == nil {
+		return perrors.New("create nacos subscribeParam failed")
 	}
 	go func() {
-		_ = nl.namingClient.Client().Subscribe(nl.subscribeParam)
+		err := nl.namingClient.Client().Subscribe(nl.subscribeParam)
+		if err == nil {
+			listenerCache.Store(nl.subscribeParam.ServiceName+nl.subscribeParam.GroupName, nl)
+		}
 	}()
 	return nil
 }
diff --git a/registry/nacos/registry.go b/registry/nacos/registry.go
index 879e8fa43b..07520fcbe4 100644
--- a/registry/nacos/registry.go
+++ b/registry/nacos/registry.go
@@ -151,7 +151,8 @@ func createDeregisterParam(url *common.URL, serviceName string, groupName string
 	}
 }
 
-func (nr *nacosRegistry) DeRegister(url *common.URL) error {
+// UnRegister
+func (nr *nacosRegistry) UnRegister(url *common.URL) error {
 	serviceName := getServiceName(url)
 	groupName := nr.URL.GetParam(constant.NacosGroupKey, defaultGroup)
 	param := createDeregisterParam(url, serviceName, groupName)
@@ -165,11 +166,6 @@ func (nr *nacosRegistry) DeRegister(url *common.URL) error {
 	return nil
 }
 
-// UnRegister
-func (nr *nacosRegistry) UnRegister(conf *common.URL) error {
-	return perrors.New("UnRegister is not support in nacosRegistry")
-}
-
 func (nr *nacosRegistry) subscribe(conf *common.URL) (registry.Listener, error) {
 	return NewNacosListener(conf, nr.URL, nr.namingClient)
 }
@@ -213,8 +209,37 @@ func (nr *nacosRegistry) Subscribe(url *common.URL, notifyListener registry.Noti
 }
 
 // UnSubscribe :
-func (nr *nacosRegistry) UnSubscribe(url *common.URL, notifyListener registry.NotifyListener) error {
-	return perrors.New("UnSubscribe not support in nacosRegistry")
+func (nr *nacosRegistry) UnSubscribe(url *common.URL, _ registry.NotifyListener) error {
+	param := createSubscribeParam(url, nr.URL, nil)
+	if param == nil {
+		return nil
+	}
+	err := nr.namingClient.Client().Unsubscribe(param)
+	if err != nil {
+		return perrors.New("UnSubscribe [" + param.ServiceName + "] to nacos failed")
+	}
+	return nil
+}
+
+func createSubscribeParam(url, regUrl *common.URL, cb callback) *vo.SubscribeParam {
+	serviceName := getSubscribeName(url)
+	groupName := regUrl.GetParam(constant.RegistryGroupKey, defaultGroup)
+	if cb == nil {
+		v, ok := listenerCache.Load(serviceName + groupName)
+		if !ok {
+			return nil
+		}
+		listener, ok := v.(*nacosListener)
+		if !ok {
+			return nil
+		}
+		cb = listener.Callback
+	}
+	return &vo.SubscribeParam{
+		ServiceName:       serviceName,
+		SubscribeCallback: cb,
+		GroupName:         groupName,
+	}
 }
 
 // GetURL gets its registration URL
@@ -231,7 +256,7 @@ func (nr *nacosRegistry) IsAvailable() bool {
 // nolint
 func (nr *nacosRegistry) Destroy() {
 	for _, url := range nr.registryUrls {
-		err := nr.DeRegister(url)
+		err := nr.UnRegister(url)
 		logger.Infof("DeRegister Nacos URL:%+v", url)
 		if err != nil {
 			logger.Errorf("Deregister URL:%+v err:%v", url, err.Error())