export registry util function to safe copy registry data

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

registry/memory/memory.go

@@ -22,17 +22,6 @@ var (
 	timeout = time.Millisecond * 10
 )
 
-/*
-// Setup sets mock data
-func (m *Registry) Setup() {
-	m.Lock()
-	defer m.Unlock()
-
-	// add some memory data
-	m.Services = Data
-}
-*/
-
 func (m *Registry) watch(r *registry.Result) {
 	var watchers []*Watcher
 
@@ -66,7 +55,7 @@ func (m *Registry) Init(opts ...registry.Option) error {
 	m.Lock()
 	for k, v := range getServices(m.options.Context) {
 		s := m.Services[k]
-		m.Services[k] = addServices(s, v)
+		m.Services[k] = registry.AddServices(s, v)
 	}
 	m.Unlock()
 	return nil
@@ -76,20 +65,20 @@ func (m *Registry) Options() registry.Options {
 	return m.options
 }
 
-func (m *Registry) GetService(service string) ([]*registry.Service, error) {
+func (m *Registry) GetService(name string) ([]*registry.Service, error) {
 	m.RLock()
-	s, ok := m.Services[service]
-	if !ok || len(s) == 0 {
-		m.RUnlock()
+	service, ok := m.Services[name]
+	m.RUnlock()
+	if !ok {
 		return nil, registry.ErrNotFound
 	}
-	m.RUnlock()
-	return s, nil
+
+	return service, nil
 }
 
 func (m *Registry) ListServices() ([]*registry.Service, error) {
-	m.RLock()
 	var services []*registry.Service
+	m.RLock()
 	for _, service := range m.Services {
 		services = append(services, service...)
 	}
@@ -99,11 +88,14 @@ func (m *Registry) ListServices() ([]*registry.Service, error) {
 
 func (m *Registry) Register(s *registry.Service, opts ...registry.RegisterOption) error {
 	go m.watch(&registry.Result{Action: "update", Service: s})
-
 	m.Lock()
-	services := addServices(m.Services[s.Name], []*registry.Service{s})
-	m.Services[s.Name] = services
+	if service, ok := m.Services[s.Name]; !ok {
+		m.Services[s.Name] = []*registry.Service{s}
+	} else {
+		m.Services[s.Name] = registry.AddServices(service, []*registry.Service{s})
+	}
 	m.Unlock()
+
 	return nil
 }
 
@@ -111,9 +103,15 @@ func (m *Registry) Deregister(s *registry.Service) error {
 	go m.watch(&registry.Result{Action: "delete", Service: s})
 
 	m.Lock()
-	services := delServices(m.Services[s.Name], []*registry.Service{s})
-	m.Services[s.Name] = services
+	if service, ok := m.Services[s.Name]; ok {
+		if service := registry.DelServices(service, []*registry.Service{s}); len(service) == 0 {
+			delete(m.Services, s.Name)
+		} else {
+			m.Services[s.Name] = service
+		}
+	}
 	m.Unlock()
+
 	return nil
 }