fix proxy protocol

metrics/noop.go

@@ -0,0 +1,45 @@
+package metrics
+
+import "github.com/go-gost/core/metrics"
+
+var (
+	nopGauge    = &noopGauge{}
+	nopCounter  = &noopCounter{}
+	nopObserver = &noopObserver{}
+
+	noop metrics.Metrics = &noopMetrics{}
+)
+
+type noopMetrics struct{}
+
+func Noop() metrics.Metrics {
+	return noop
+}
+
+func (m *noopMetrics) Counter(name metrics.MetricName, labels metrics.Labels) metrics.Counter {
+	return nopCounter
+}
+
+func (m *noopMetrics) Gauge(name metrics.MetricName, labels metrics.Labels) metrics.Gauge {
+	return nopGauge
+}
+
+func (m *noopMetrics) Observer(name metrics.MetricName, labels metrics.Labels) metrics.Observer {
+	return nopObserver
+}
+
+type noopGauge struct{}
+
+func (*noopGauge) Inc()          {}
+func (*noopGauge) Dec()          {}
+func (*noopGauge) Add(v float64) {}
+func (*noopGauge) Set(v float64) {}
+
+type noopCounter struct{}
+
+func (*noopCounter) Inc()          {}
+func (*noopCounter) Add(v float64) {}
+
+type noopObserver struct{}
+
+func (*noopObserver) Observe(v float64) {}