remove unnecessary metric wrapper

metrics/metrics.go

@@ -17,17 +17,21 @@ const (
 type Labels map[string]string
 
 var (
-	metrics Metrics = Noop()
+	global Metrics = Noop()
 )
 
 func SetGlobal(m Metrics) {
 	if m != nil {
-		metrics = m
+		global = m
 	} else {
-		metrics = Noop()
+		global = Noop()
 	}
 }
 
+func Global() Metrics {
+	return global
+}
+
 type Gauge interface {
 	Inc()
 	Dec()
@@ -51,13 +55,13 @@ type Metrics interface {
 }
 
 func GetCounter(name MetricName, labels Labels) Counter {
-	return metrics.Counter(name, labels)
+	return global.Counter(name, labels)
 }
 
 func GetGauge(name MetricName, labels Labels) Gauge {
-	return metrics.Gauge(name, labels)
+	return global.Gauge(name, labels)
 }
 
 func GetObserver(name MetricName, labels Labels) Observer {
-	return metrics.Observer(name, labels)
+	return global.Observer(name, labels)
 }

metrics/wrapper/conn.go

@@ -13,7 +13,7 @@ var (
 	errUnsupport = errors.New("unsupported operation")
 )
 
-// ServerConn is a server side Conn with metrics supported.
+// serverConn is a server side Conn with metrics supported.
 type serverConn struct {
 	net.Conn
 	service string

metrics/wrapper/listener.go

@@ -1,6 +1,10 @@
 package wrapper
 
-import "net"
+import (
+	"net"
+
+	"github.com/go-gost/core/metrics"
+)
 
 type listener struct {
 	service string
@@ -19,5 +23,10 @@ func (ln *listener) Accept() (net.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	// metrics is not enabled
+	if metrics.Global() == metrics.Noop() {
+		return c, nil
+	}
 	return WrapConn(ln.service, c), nil
 }