feat: refactor register func (#1807)

Co-authored-by: huanghuan.27@bytedance.com <huanghuan.27@bytedance.com>
Co-authored-by: Asim Aslam <asim@aslam.me>

registry/mdns_registry.go

@@ -1,4 +1,3 @@
-// Package mdns is a multicast dns registry
 package registry
 
 import (
@@ -44,6 +43,7 @@ type mdnsEntry struct {
 // used for listing
 type services map[string][]*mdnsEntry
 
+// mdsRegistry is a multicast dns registry
 type mdnsRegistry struct {
 	opts Options
 
@@ -136,6 +136,7 @@ func decode(record []string) (*mdnsTxt, error) {
 
 	return txt, nil
 }
+
 func newRegistry(opts ...Option) Registry {
 	options := Options{
 		Context: context.Background(),
@@ -148,9 +149,7 @@ func newRegistry(opts ...Option) Registry {
 
 	// set the domain
 	defaultDomain := DefaultDomain
-
-	d, ok := options.Context.Value("mdns.domain").(string)
-	if ok {
+	if d, ok := options.Context.Value("mdns.domain").(string); ok {
 		defaultDomain = d
 	}
 
@@ -192,35 +191,23 @@ func createServiceMDNSEntry(name, domain string) (*mdnsEntry, error) {
 	return &mdnsEntry{id: "*", node: srv}, nil
 }
 
-func (m *mdnsRegistry) Register(service *Service, opts ...RegisterOption) error {
-	m.Lock()
-
-	// parse the options
-	var options RegisterOptions
-	for _, o := range opts {
-		o(&options)
-	}
-	if len(options.Domain) == 0 {
-		options.Domain = m.defaultDomain
-	}
-
-	// create the domain in the memory store if it doesn't yet exist
-	if _, ok := m.domains[options.Domain]; !ok {
-		m.domains[options.Domain] = make(services)
+func (m *mdnsRegistry) getMdnsEntries(domain, serviceName string) ([]*mdnsEntry, error) {
+	entries, ok := m.domains[domain][serviceName]
+	if ok {
+		return entries, nil
 	}
 
 	// create the wildcard entry used for list queries in this domain
-	entries, ok := m.domains[options.Domain][service.Name]
-	if !ok {
-		entry, err := createServiceMDNSEntry(service.Name, options.Domain)
+	entry, err := createServiceMDNSEntry(serviceName, domain)
 	if err != nil {
-			m.Unlock()
-			return err
-		}
-		entries = append(entries, entry)
+		return nil, err
 	}
 
-	var gerr error
+	return []*mdnsEntry{entry}, nil
+}
+
+func registerService(service *Service, entries []*mdnsEntry, options RegisterOptions) ([]*mdnsEntry, error) {
+	var lastError error
 	for _, node := range service.Nodes {
 		var seen bool
 
@@ -244,13 +231,13 @@ func (m *mdnsRegistry) Register(service *Service, opts ...RegisterOption) error
 		})
 
 		if err != nil {
-			gerr = err
+			lastError = err
 			continue
 		}
 
 		host, pt, err := net.SplitHostPort(node.Address)
 		if err != nil {
-			gerr = err
+			lastError = err
 			continue
 		}
 		port, _ := strconv.Atoi(pt)
@@ -269,25 +256,23 @@ func (m *mdnsRegistry) Register(service *Service, opts ...RegisterOption) error
 			txt,
 		)
 		if err != nil {
-			gerr = err
+			lastError = err
 			continue
 		}
 
 		srv, err := mdns.NewServer(&mdns.Config{Zone: s, LocalhostChecking: true})
 		if err != nil {
-			gerr = err
+			lastError = err
 			continue
 		}
 
 		entries = append(entries, &mdnsEntry{id: node.Id, node: srv})
 	}
 
-	// save the mdns entry
-	m.domains[options.Domain][service.Name] = entries
-	m.Unlock()
+	return entries, lastError
+}
 
-	// register in the global Domain so it can be queried as one
-	if options.Domain != m.globalDomain {
+func createGlobalDomainService(service *Service, options RegisterOptions) *Service {
 	srv := *service
 	srv.Nodes = nil
 
@@ -304,7 +289,42 @@ func (m *mdnsRegistry) Register(service *Service, opts ...RegisterOption) error
 		srv.Nodes = append(srv.Nodes, node)
 	}
 
-		if err := m.Register(&srv, append(opts, RegisterDomain(m.globalDomain))...); err != nil {
+	return &srv
+}
+
+func (m *mdnsRegistry) Register(service *Service, opts ...RegisterOption) error {
+	m.Lock()
+
+	// parse the options
+	var options RegisterOptions
+	for _, o := range opts {
+		o(&options)
+	}
+	if len(options.Domain) == 0 {
+		options.Domain = m.defaultDomain
+	}
+
+	// create the domain in the memory store if it doesn't yet exist
+	if _, ok := m.domains[options.Domain]; !ok {
+		m.domains[options.Domain] = make(services)
+	}
+
+	entries, err := m.getMdnsEntries(options.Domain, service.Name)
+	if err != nil {
+		m.Unlock()
+		return err
+	}
+
+	entries, gerr := registerService(service, entries, options)
+
+	// save the mdns entry
+	m.domains[options.Domain][service.Name] = entries
+	m.Unlock()
+
+	// register in the global Domain so it can be queried as one
+	if options.Domain != m.globalDomain {
+		srv := createGlobalDomainService(service, options)
+		if err := m.Register(srv, append(opts, RegisterDomain(m.globalDomain))...); err != nil {
 			gerr = err
 		}
 	}

registry/mdns_test.go

@@ -79,7 +79,6 @@ func TestMDNS(t *testing.T) {
 
 		if len(s) != 1 {
 			t.Fatalf("Expected one result for %s got %d", service.Name, len(s))
-
 		}
 
 		if s[0].Name != service.Name {