Merge pull request #1012 from Astone-Chou/lint

improve code quality

agent/input/telegram/conn.go

@@ -44,11 +44,9 @@ func (tc *telegramConn) run() {
 	tc.recv = updates
 	tc.syncCond.Signal()
 
-	for {
-		select {
-		case <-tc.exit:
-			return
-		}
+	select {
+	case <-tc.exit:
+		return
 	}
 }
 

client/grpc/grpc.go

@@ -339,7 +339,9 @@ func (g *grpcClient) Call(ctx context.Context, req client.Request, rsp interface
 	d, ok := ctx.Deadline()
 	if !ok {
 		// no deadline so we create a new one
-		ctx, _ = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		defer cancel()
 	} else {
 		// got a deadline so no need to setup context
 		// but we need to set the timeout we pass along

client/rpc_client.go

@@ -162,7 +162,6 @@ func (r *rpcClient) call(ctx context.Context, node *registry.Node, req Request,
 
 	select {
 	case err := <-ch:
-		grr = err
 		return err
 	case <-ctx.Done():
 		grr = errors.Timeout("go.micro.client", fmt.Sprintf("%v", ctx.Err()))
@@ -378,7 +377,9 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 	d, ok := ctx.Deadline()
 	if !ok {
 		// no deadline so we create a new one
-		ctx, _ = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		defer cancel()
 	} else {
 		// got a deadline so no need to setup context
 		// but we need to set the timeout we pass along

codec/bytes/bytes.go

@@ -29,12 +29,10 @@ func (c *Codec) ReadBody(b interface{}) error {
 		return err
 	}
 
-	switch b.(type) {
+	switch v := b.(type) {
 	case *[]byte:
-		v := b.(*[]byte)
 		*v = buf
 	case *Frame:
-		v := b.(*Frame)
 		v.Data = buf
 	default:
 		return fmt.Errorf("failed to read body: %v is not type of *[]byte", b)
@@ -45,14 +43,13 @@ func (c *Codec) ReadBody(b interface{}) error {
 
 func (c *Codec) Write(m *codec.Message, b interface{}) error {
 	var v []byte
-	switch b.(type) {
+	switch vb := b.(type) {
 	case *Frame:
-		v = b.(*Frame).Data
+		v = vb.Data
 	case *[]byte:
-		ve := b.(*[]byte)
-		v = *ve
+		v = *vb
 	case []byte:
-		v = b.([]byte)
+		v = vb
 	default:
 		return fmt.Errorf("failed to write: %v is not type of *[]byte or []byte", b)
 	}

codec/bytes/marshaler.go

@@ -12,25 +12,22 @@ type Message struct {
 }
 
 func (n Marshaler) Marshal(v interface{}) ([]byte, error) {
-	switch v.(type) {
+	switch ve := v.(type) {
 	case *[]byte:
-		ve := v.(*[]byte)
 		return *ve, nil
 	case []byte:
-		return v.([]byte), nil
+		return ve, nil
 	case *Message:
-		return v.(*Message).Body, nil
+		return ve.Body, nil
 	}
 	return nil, errors.New("invalid message")
 }
 
 func (n Marshaler) Unmarshal(d []byte, v interface{}) error {
-	switch v.(type) {
+	switch ve := v.(type) {
 	case *[]byte:
-		ve := v.(*[]byte)
 		*ve = d
 	case *Message:
-		ve := v.(*Message)
 		ve.Body = d
 	}
 	return errors.New("invalid message")

codec/text/text.go

@@ -29,15 +29,12 @@ func (c *Codec) ReadBody(b interface{}) error {
 		return err
 	}
 
-	switch b.(type) {
+	switch v := b.(type) {
 	case *string:
-		v := b.(*string)
 		*v = string(buf)
 	case *[]byte:
-		v := b.(*[]byte)
 		*v = buf
 	case *Frame:
-		v := b.(*Frame)
 		v.Data = buf
 	default:
 		return fmt.Errorf("failed to read body: %v is not type of *[]byte", b)
@@ -48,20 +45,17 @@ func (c *Codec) ReadBody(b interface{}) error {
 
 func (c *Codec) Write(m *codec.Message, b interface{}) error {
 	var v []byte
-	switch b.(type) {
+	switch ve := b.(type) {
 	case *Frame:
-		v = b.(*Frame).Data
+		v = ve.Data
 	case *[]byte:
-		ve := b.(*[]byte)
 		v = *ve
 	case *string:
-		ve := b.(*string)
 		v = []byte(*ve)
 	case string:
-		ve := b.(string)
 		v = []byte(ve)
 	case []byte:
-		v = b.([]byte)
+		v = ve
 	default:
 		return fmt.Errorf("failed to write: %v is not type of *[]byte or []byte", b)
 	}

network/default.go

@@ -823,7 +823,7 @@ func (n *network) processCtrlChan(listener tunnel.Listener) {
 					log.Tracef("Network metric for router %s and gateway %s: %v", event.Route.Router, event.Route.Gateway, metric)
 
 					// check we don't overflow max int 64
-					if d := route.Metric + metric; d > math.MaxInt64 || d <= 0 {
+					if d := route.Metric + metric; d <= 0 {
 						// set to max int64 if we overflow
 						route.Metric = math.MaxInt64
 					} else {

network/service/handler/handler.go

@@ -94,11 +94,6 @@ func (n *Network) Connect(ctx context.Context, req *pbNet.ConnectRequest, resp *
 
 // Nodes returns the list of nodes
 func (n *Network) Nodes(ctx context.Context, req *pbNet.NodesRequest, resp *pbNet.NodesResponse) error {
-	depth := uint(req.Depth)
-	if depth <= 0 || depth > network.MaxDepth {
-		depth = network.MaxDepth
-	}
-
 	// root node
 	nodes := map[string]network.Node{}
 

proxy/mucp/mucp.go

@@ -274,7 +274,7 @@ func (p *Proxy) watchRoutes() {
 			return
 		}
 
-		if err := p.manageRoutes(event.Route, fmt.Sprintf("%s", event.Type)); err != nil {
+		if err := p.manageRoutes(event.Route, event.Type.String()); err != nil {
 			// TODO: should we bail here?
 			continue
 		}
@@ -562,12 +562,9 @@ func NewProxy(opts ...options.Option) proxy.Proxy {
 		defer t.Stop()
 
 		// we must refresh route metrics since they do not trigger new events
-		for {
-			select {
-			case <-t.C:
-				// refresh route metrics
-				p.refreshMetrics()
-			}
+		for range t.C {
+			// refresh route metrics
+			p.refreshMetrics()
 		}
 	}()
 

registry/mdns_registry.go

@@ -230,7 +230,9 @@ func (m *mdnsRegistry) GetService(service string) ([]*Service, error) {
 
 	p := mdns.DefaultParams(service)
 	// set context with timeout
-	p.Context, _ = context.WithTimeout(context.Background(), m.opts.Timeout)
+	var cancel context.CancelFunc
+	p.Context, cancel = context.WithTimeout(context.Background(), m.opts.Timeout)
+	defer cancel()
 	// set entries channel
 	p.Entries = entries
 	// set the domain
@@ -308,7 +310,9 @@ func (m *mdnsRegistry) ListServices() ([]*Service, error) {
 
 	p := mdns.DefaultParams("_services")
 	// set context with timeout
-	p.Context, _ = context.WithTimeout(context.Background(), m.opts.Timeout)
+	var cancel context.CancelFunc
+	p.Context, cancel = context.WithTimeout(context.Background(), m.opts.Timeout)
+	defer cancel()
 	// set entries channel
 	p.Entries = entries
 	// set domain

registry/service/watcher.go

@@ -11,24 +11,22 @@ type serviceWatcher struct {
 }
 
 func (s *serviceWatcher) Next() (*registry.Result, error) {
-	for {
-		// check if closed
-		select {
-		case <-s.closed:
-			return nil, registry.ErrWatcherStopped
-		default:
-		}
-
-		r, err := s.stream.Recv()
-		if err != nil {
-			return nil, err
-		}
-
-		return &registry.Result{
-			Action:  r.Action,
-			Service: ToService(r.Service),
-		}, nil
+	// check if closed
+	select {
+	case <-s.closed:
+		return nil, registry.ErrWatcherStopped
+	default:
 	}
+
+	r, err := s.stream.Recv()
+	if err != nil {
+		return nil, err
+	}
+
+	return &registry.Result{
+		Action:  r.Action,
+		Service: ToService(r.Service),
+	}, nil
 }
 
 func (s *serviceWatcher) Stop() {

router/default.go

@@ -718,7 +718,7 @@ func (r *router) Process(a *Advert) error {
 		route := event.Route
 		action := event.Type
 		log.Debugf("Router %s applying %s from router %s for service %s %s", r.options.Id, action, route.Router, route.Service, route.Address)
-		if err := r.manageRoute(route, fmt.Sprintf("%s", action)); err != nil {
+		if err := r.manageRoute(route, action.String()); err != nil {
 			return fmt.Errorf("failed applying action %s to routing table: %s", action, err)
 		}
 	}

server/grpc/grpc.go

@@ -222,7 +222,9 @@ func (g *grpcServer) handler(srv interface{}, stream grpc.ServerStream) error {
 	// set the timeout if we have it
 	if len(to) > 0 {
 		if n, err := strconv.ParseUint(to, 10, 64); err == nil {
-			ctx, _ = context.WithTimeout(ctx, time.Duration(n))
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithTimeout(ctx, time.Duration(n))
+			defer cancel()
 		}
 	}
 

server/rpc_server.go

@@ -277,7 +277,9 @@ func (s *rpcServer) ServeConn(sock transport.Socket) {
 		// set the timeout from the header if we have it
 		if len(to) > 0 {
 			if n, err := strconv.ParseUint(to, 10, 64); err == nil {
-				ctx, _ = context.WithTimeout(ctx, time.Duration(n))
+				var cancel context.CancelFunc
+				ctx, cancel = context.WithTimeout(ctx, time.Duration(n))
+				defer cancel()
 			}
 		}
 

server/server.go

@@ -201,7 +201,7 @@ func Run() error {
 	}
 
 	ch := make(chan os.Signal, 1)
-	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT, syscall.SIGKILL)
+	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT)
 	log.Logf("Received signal %s", <-ch)
 
 	return Stop()

sync/leader/etcd/etcd.go

@@ -39,9 +39,7 @@ func (e *etcdLeader) Elect(id string, opts ...leader.ElectOption) (leader.Electe
 
 	l := cc.NewElection(s, path)
 
-	ctx, _ := context.WithCancel(context.Background())
-
-	if err := l.Campaign(ctx, id); err != nil {
+	if err := l.Campaign(context.TODO(), id); err != nil {
 		return nil, err
 	}
 
@@ -63,14 +61,8 @@ func (e *etcdLeader) Follow() chan string {
 	ech := l.Observe(context.Background())
 
 	go func() {
-		for {
-			select {
-			case r, ok := <-ech:
-				if !ok {
-					return
-				}
-				ch <- string(r.Kvs[0].Value)
-			}
+		for r := range ech {
+			ch <- string(r.Kvs[0].Value)
 		}
 	}()
 
@@ -82,8 +74,7 @@ func (e *etcdLeader) String() string {
 }
 
 func (e *etcdElected) Reelect() error {
-	ctx, _ := context.WithCancel(context.Background())
-	return e.e.Campaign(ctx, e.id)
+	return e.e.Campaign(context.TODO(), e.id)
 }
 
 func (e *etcdElected) Revoked() chan bool {

sync/lock/etcd/etcd.go

@@ -49,9 +49,7 @@ func (e *etcdLock) Acquire(id string, opts ...lock.AcquireOption) error {
 
 	m := cc.NewMutex(s, path)
 
-	ctx, _ := context.WithCancel(context.Background())
-
-	if err := m.Lock(ctx); err != nil {
+	if err := m.Lock(context.TODO()); err != nil {
 		return err
 	}
 

sync/task/task.go

@@ -63,7 +63,9 @@ func (s Schedule) Run() <-chan time.Time {
 		}
 
 		// start ticker
-		for t := range time.Tick(s.Interval) {
+		ticker := time.NewTicker(s.Interval)
+		defer ticker.Stop()
+		for t := range ticker.C {
 			ch <- t
 		}
 	}()

tunnel/link.go

@@ -228,7 +228,7 @@ func (l *link) manage() {
 			}
 			// check the type of message
 			switch {
-			case bytes.Compare(p.message.Body, linkRequest) == 0:
+			case bytes.Equal(p.message.Body, linkRequest):
 				log.Tracef("Link %s received link request %v", l.id, p.message.Body)
 				// send response
 				if err := send(linkResponse); err != nil {
@@ -236,7 +236,7 @@ func (l *link) manage() {
 					l.errCount++
 					l.Unlock()
 				}
-			case bytes.Compare(p.message.Body, linkResponse) == 0:
+			case bytes.Equal(p.message.Body, linkResponse):
 				// set round trip time
 				d := time.Since(now)
 				log.Tracef("Link %s received link response in %v", p.message.Body, d)

web/service.go

@@ -376,7 +376,7 @@ func (s *service) Run() error {
 	go s.run(ex)
 
 	ch := make(chan os.Signal, 1)
-	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT, syscall.SIGKILL)
+	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT)
 
 	select {
 	// wait on kill signal