add metadata and histograms to benchmark

exporter/prometheusremotewriteexporter/exporter_test.go

@@ -1214,17 +1214,51 @@ func benchmarkExecute(b *testing.B, numSample int) {
 		return samples
 	}
 
+	generateHistograms := func(n int) []prompb.Histogram {
+		histograms := make([]prompb.Histogram, 0, n)
+		for i := 0; i < n; i++ {
+			histograms = append(histograms, prompb.Histogram{
+				Timestamp:      int64(i),
+				Count:          &prompb.Histogram_CountInt{CountInt: uint64(i)},
+				PositiveCounts: []float64{float64(i)},
+			})
+		}
+		return histograms
+	}
+
 	reqs := make([]*prompb.WriteRequest, 0, b.N)
 	const labelValue = "abcdefg'hijlmn234!@#$%^&*()_+~`\"{}[],./<>?hello0123hiOlá你好Dzieńdobry9Zd8ra765v4stvuyte"
 	for n := 0; n < b.N; n++ {
 		num := strings.Repeat(strconv.Itoa(n), 16)
 		req := &prompb.WriteRequest{
-			Timeseries: []prompb.TimeSeries{{
-				Samples: generateSamples(numSample),
-				Labels: []prompb.Label{
-					{Name: "__name__", Value: "test_metric"},
-					{Name: "test_label_name_" + num, Value: labelValue + num},
-				}}},
+			Metadata: []prompb.MetricMetadata{
+				{
+					Type: prompb.MetricMetadata_COUNTER,
+					Unit: "seconds",
+					Help: "This is a counter",
+				},
+				{
+					Type: prompb.MetricMetadata_HISTOGRAM,
+					Unit: "seconds",
+					Help: "This is a histogram",
+				},
+			},
+			Timeseries: []prompb.TimeSeries{
+				{
+					Samples: generateSamples(numSample),
+					Labels: []prompb.Label{
+						{Name: "__name__", Value: "test_metric"},
+						{Name: "test_label_name_" + num, Value: labelValue + num},
+					},
+				},
+				{
+					Histograms: generateHistograms(numSample),
+					Labels: []prompb.Label{
+						{Name: "__name__", Value: "test_histogram"},
+						{Name: "test_label_name_" + num, Value: labelValue + num},
+					},
+				},
+			},
 		}
 		reqs = append(reqs, req)
 	}