lib/promscrape: add a benchmark for internLabelStrings()

lib/promscrape/config_timing_test.go

@@ -0,0 +1,31 @@
+package promscrape
+
+import (
+	"testing"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+)
+
+func BenchmarkInternLabelStrings(b *testing.B) {
+	b.ReportAllocs()
+	b.SetBytes(1)
+	b.RunParallel(func(pb *testing.PB) {
+		labels := []prompbmarshal.Label{
+			{
+				Name:  "job",
+				Value: "node-exporter",
+			},
+			{
+				Name:  "instance",
+				Value: "foo.bar.baz:1234",
+			},
+			{
+				Name:  "__meta_kubernetes_namespace",
+				Value: "default",
+			},
+		}
+		for pb.Next() {
+			internLabelStrings(labels)
+		}
+	})
+}