separate p2p Streamer from p2p Service

cmd/bee/main.go

@@ -22,6 +22,7 @@ func main() {
 
 	//var idht *dht.IpfsDHT
 
+	// Construct P2P service.
 	s, err := libp2p.New(ctx, libp2p.Options{
 		// Routing: func(h host.Host) (r routing.PeerRouting, err error) {
 		// 	idht, err = dht.New(ctx, h)
@@ -32,11 +33,16 @@ func main() {
 		log.Fatal("p2p service: ", err)
 	}
 
-	pingPong, err := pingpong.New(s)
-	if err != nil {
+	// Construct protocols.
+	pingPong := pingpong.New(s)
+
+	// Add protocols to the P2P service.
+	if err = s.AddProtocol(pingPong.Protocol()); err != nil {
 		log.Fatal("pingpong service: ", err)
 	}
 
+	// Bellow is only demo code.
+
 	addrs, err := s.Addresses()
 	if err != nil {
 		log.Fatal("get server addresses: ", err)

pkg/p2p/p2p.go

@@ -11,6 +11,9 @@ import (
 type Service interface {
 	AddProtocol(ProtocolSpec) error
 	Connect(ctx context.Context, addr ma.Multiaddr) (peerID string, err error)
+}
+
+type Streamer interface {
 	NewStream(ctx context.Context, peerID, protocol, stream, version string) (Stream, error)
 }
 

pkg/pingpong/pingpong.go

@@ -20,15 +20,15 @@ const (
 )
 
 type Service struct {
-	p2p p2p.Service
+	streamer p2p.Streamer
 }
 
-func New(p2ps p2p.Service) (s *Service, err error) {
-	s = &Service{
-		p2p: p2ps,
-	}
+func New(streamer p2p.Streamer) *Service {
+	return &Service{streamer: streamer}
+}
 
-	if err := p2ps.AddProtocol(p2p.ProtocolSpec{
+func (s *Service) Protocol() p2p.ProtocolSpec {
+	return p2p.ProtocolSpec{
 		Name: protocolName,
 		StreamSpecs: []p2p.StreamSpec{
 			{
@@ -37,10 +37,7 @@ func New(p2ps p2p.Service) (s *Service, err error) {
 				Handler: s.Handler,
 			},
 		},
-	}); err != nil {
-		return nil, err
 	}
-	return s, nil
 }
 
 func (s *Service) Handler(p p2p.Peer) {
@@ -68,7 +65,7 @@ func (s *Service) Handler(p p2p.Peer) {
 }
 
 func (s *Service) Ping(ctx context.Context, peerID string, msgs ...string) (rtt time.Duration, err error) {
-	stream, err := s.p2p.NewStream(ctx, peerID, protocolName, streamName, streamVersion)
+	stream, err := s.streamer.NewStream(ctx, peerID, protocolName, streamName, streamVersion)
 	if err != nil {
 		return 0, fmt.Errorf("new stream: %w", err)
 	}