perf(all): use strings.Cut and strings.LastIndexByte for better performance

config/options.go

@@ -137,12 +137,12 @@ func resolver(input map[string]any, mapper func(name string) string, toType bool
 
 func mapper(input map[string]any) func(name string) string {
 	mapper := func(name string) string {
-		args := strings.SplitN(strings.TrimSpace(name), ":", 2) //nolint:mnd
-		if v, has := readValue(input, args[0]); has {
+		key, value, cut := strings.Cut(strings.TrimSpace(name), ":")
+		if v, has := readValue(input, key); has {
 			s, _ := v.String()
 			return s
-		} else if len(args) > 1 { // default value
-			return args[1]
+		} else if cut { // default value
+			return value
 		}
 		return ""
 	}

contrib/config/apollo/apollo.go

@@ -130,9 +130,12 @@ func NewSource(opts ...Option) config.Source {
 }
 
 func format(ns string) string {
-	arr := strings.Split(ns, ".")
-	suffix := arr[len(arr)-1]
-	if len(arr) <= 1 || suffix == properties {
+	lastDot := strings.LastIndexByte(ns, '.')
+	if lastDot == -1 || lastDot == len(ns)-1 {
+		return json
+	}
+	suffix := ns[lastDot+1:]
+	if suffix == properties {
 		return json
 	}
 	if _, ok := formats[suffix]; !ok {
@@ -258,19 +261,19 @@ func resolve(key string, value any, target map[string]any) {
 // genKey got the key of config.KeyValue pair.
 // eg: namespace.ext with subKey got namespace.subKey
 func genKey(ns, sub string) string {
-	arr := strings.Split(ns, ".")
-	if len(arr) == 1 {
-		if ns == "" {
-			return sub
-		}
+	if ns == "" {
+		return sub
+	}
 
+	lastDot := strings.LastIndexByte(ns, '.')
+	if lastDot == -1 || lastDot == len(ns)-1 {
 		return ns + "." + sub
 	}
 
-	suffix := arr[len(arr)-1]
+	suffix := ns[lastDot+1:]
 	_, ok := formats[suffix]
 	if ok {
-		return strings.Join(arr[:len(arr)-1], ".") + "." + sub
+		return ns[:lastDot] + "." + sub
 	}
 
 	return ns + "." + sub

contrib/registry/consul/client.go

@@ -57,9 +57,9 @@ func defaultResolver(_ context.Context, entries []*api.ServiceEntry) []*registry
 	for _, entry := range entries {
 		var version string
 		for _, tag := range entry.Service.Tags {
-			ss := strings.SplitN(tag, "=", 2)
-			if len(ss) == 2 && ss[0] == "version" {
-				version = ss[1]
+			k, v, cut := strings.Cut(tag, "=")
+			if cut && k == "version" {
+				version = v
 			}
 		}
 		endpoints := make([]string, 0)

contrib/registry/kubernetes/registry.go

@@ -388,7 +388,7 @@ func getServiceInstanceFromPod(pod *corev1.Pod) (*registry.ServiceInstance, erro
 			protocol := protocolMap.GetProtocol(port)
 			if protocol == "" {
 				if cp.Name != "" {
-					protocol = strings.Split(cp.Name, "-")[0]
+					protocol, _, _ = strings.Cut(cp.Name, "-")
 				} else {
 					protocol = string(cp.Protocol)
 				}

middleware/auth/jwt/jwt.go

@@ -89,11 +89,10 @@ func Server(keyFunc jwt.Keyfunc, opts ...Option) middleware.Middleware {
 				if keyFunc == nil {
 					return nil, ErrMissingKeyFunc
 				}
-				auths := strings.SplitN(header.RequestHeader().Get(authorizationKey), " ", 2)
-				if len(auths) != 2 || !strings.EqualFold(auths[0], bearerWord) {
+				bearer, jwtToken, cut := strings.Cut(header.RequestHeader().Get(authorizationKey), " ")
+				if !cut || !strings.EqualFold(bearer, bearerWord) {
 					return nil, ErrMissingJwtToken
 				}
-				jwtToken := auths[1]
 				var (
 					tokenInfo *jwt.Token
 					err       error

middleware/tracing/span.go

@@ -103,17 +103,17 @@ func setServerSpan(ctx context.Context, span trace.Span, m any) {
 // on a gRPC's FullMethod.
 func parseFullMethod(fullMethod string) (string, []attribute.KeyValue) {
 	name := strings.TrimLeft(fullMethod, "/")
-	parts := strings.SplitN(name, "/", 2)
-	if len(parts) != 2 { //nolint:mnd
+	service, method, cut := strings.Cut(name, "/")
+	if !cut {
 		// Invalid format, does not follow `/package.service/method`.
 		return name, []attribute.KeyValue{attribute.Key("rpc.operation").String(fullMethod)}
 	}
 
 	var attrs []attribute.KeyValue
-	if service := parts[0]; service != "" {
+	if service != "" {
 		attrs = append(attrs, semconv.RPCServiceKey.String(service))
 	}
-	if method := parts[1]; method != "" {
+	if method != "" {
 		attrs = append(attrs, semconv.RPCMethodKey.String(method))
 	}
 	return name, attrs