func()

in pkg/adapter/springcloud/cloud.go [284:336]

• 38 lines of code
• 9 McCabe index (conditional complexity)

func (a *CloudAdapter) fetchCompareAndSet() {
	instances, err := a.fetchServiceByConfig()
	if err != nil {
		logger.Warnf("fetchCompareAndSet all service error ", err.Error())
		return
	}
	_ = a.watch()
	// manage cluster and route
	cm := server.GetClusterManager()
	rm := server.GetRouterManager()

	a.mutex.Lock()
	defer a.mutex.Unlock()

	oldStore, err := cm.CloneStore()

	if err != nil {
		logger.Warnf("fetchCompareAndSet clone store error ", err.Error())
	}

	newStore := cm.NewStore(oldStore.Version)

	for _, instance := range instances {
		endpoint := instance.ToEndpoint()
		// endpoint name should equal with cluster name
		newStore.SetEndpoint(endpoint.Name, endpoint)
	}

	// maximize reduction the interval of down state
	// first remove the router for removed cluster
	for _, c := range oldStore.Config {
		if !newStore.HasCluster(c.Name) {
			rm.DeleteRouter(&model.Router{ID: c.Name})
		}
	}
	// second set cluster
	ret := cm.CompareAndSetStore(newStore)

	if !ret {
		// fast fail the delete route at first phase shouldn't recover
		return
	}

	// third add new router
	for _, c := range newStore.Config {
		if !oldStore.HasCluster(c.Name) {
			match := model.NewRouterMatchPrefix(c.Name)
			route := model.RouteAction{Cluster: c.Name}
			added := &model.Router{ID: c.Name, Match: match, Route: route}
			rm.AddRouter(added)
		}
	}
}