add traffic limiter option for handler

limiter/traffic/limiter.go

@@ -10,7 +10,40 @@ type Limiter interface {
 	Set(n int)
 }
 
-type TrafficLimiter interface {
-	In(key string) Limiter
-	Out(key string) Limiter
+type Options struct {
+	Network string
+	Addr    string
+	Client  string
+	Src     string
+}
+
+type Option func(opts *Options)
+
+func NetworkOption(network string) Option {
+	return func(opts *Options) {
+		opts.Network = network
+	}
+}
+
+func AddrOption(addr string) Option {
+	return func(opts *Options) {
+		opts.Addr = addr
+	}
+}
+
+func ClientOption(client string) Option {
+	return func(opts *Options) {
+		opts.Client = client
+	}
+}
+
+func SrcOption(src string) Option {
+	return func(opts *Options) {
+		opts.Src = src
+	}
+}
+
+type TrafficLimiter interface {
+	In(ctx context.Context, key string, opts ...Option) Limiter
+	Out(ctx context.Context, key string, opts ...Option) Limiter
 }