Add benchmark

exporters/metric/prometheus/go.sum

@@ -92,6 +92,7 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+go.opentelemetry.io v0.1.0 h1:EANZoRCOP+A3faIlw/iN6YEWoYb1vleZRKm1EvH8T48=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=

exporters/metric/prometheus/prometheus.go

@@ -20,13 +20,11 @@ import (
 	"net/http"
 	"sync"
 
-	"go.opentelemetry.io/otel/api/metric"
-
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
 	"go.opentelemetry.io/otel/api/global"
-	"go.opentelemetry.io/otel/api/label"
+	"go.opentelemetry.io/otel/api/metric"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregator"
 	"go.opentelemetry.io/otel/sdk/metric/controller/pull"
@@ -203,7 +201,7 @@ func (c *collector) Describe(ch chan<- *prometheus.Desc) {
 	defer c.exp.lock.RUnlock()
 
 	_ = c.exp.Controller().ForEach(func(record export.Record) error {
-		ch <- c.toDesc(&record)
+		ch <- c.toDesc(record)
 		return nil
 	})
 }
@@ -222,9 +220,8 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
 	err := ctrl.ForEach(func(record export.Record) error {
 		agg := record.Aggregator()
 		numberKind := record.Descriptor().NumberKind()
-		// TODO: Use the resource value in this record.
-		labels := labelValues(record.Labels())
-		desc := c.toDesc(&record)
+		labels := labelValues(record)
+		desc := c.toDesc(record)
 
 		if hist, ok := agg.(aggregator.Histogram); ok {
 			if err := c.exportHistogram(ch, hist, numberKind, desc, labels); err != nil {
@@ -346,30 +343,35 @@ func (c *collector) exportHistogram(ch chan<- prometheus.Metric, hist aggregator
 	return nil
 }
 
-func (c *collector) toDesc(record *export.Record) *prometheus.Desc {
+func (c *collector) toDesc(record export.Record) *prometheus.Desc {
 	desc := record.Descriptor()
-	labels := labelsKeys(record.Labels())
+	labels := labelsKeys(record)
 	return prometheus.NewDesc(sanitize(desc.Name()), desc.Description(), labels, nil)
 }
 
-func labelsKeys(labels *label.Set) []string {
-	iter := labels.Iter()
-	keys := make([]string, 0, iter.Len())
-	for iter.Next() {
-		kv := iter.Label()
-		keys = append(keys, sanitize(string(kv.Key)))
+func labelsKeys(record export.Record) []string {
+	iter1 := record.Resource().Iter()
+	iter2 := record.Labels().Iter()
+	keys := make([]string, 0, iter1.Len()+iter2.Len())
+	for iter1.Next() {
+		keys = append(keys, sanitize(string(iter1.Label().Key)))
+	}
+	for iter2.Next() {
+		keys = append(keys, sanitize(string(iter2.Label().Key)))
 	}
 	return keys
 }
 
-func labelValues(labels *label.Set) []string {
-	// TODO(paivagustavo): parse the labels.Encoded() instead of calling `Emit()` directly
-	//  this would avoid unnecessary allocations.
-	iter := labels.Iter()
-	values := make([]string, 0, iter.Len())
-	for iter.Next() {
-		label := iter.Label()
-		values = append(values, label.Value.Emit())
+func labelValues(record export.Record) []string {
+	iter1 := record.Resource().Iter()
+	iter2 := record.Labels().Iter()
+	values := make([]string, 0, iter1.Len()+iter2.Len())
+	for iter1.Next() {
+		values = append(values, iter1.Label().Value.Emit())
 	}
+	for iter2.Next() {
+		values = append(values, iter2.Label().Value.Emit())
+	}
+
 	return values
 }

sdk/resource/benchmark_test.go

@@ -0,0 +1,84 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource_test
+
+import (
+	"fmt"
+	"math/rand"
+	"testing"
+
+	"go.opentelemetry.io/otel/api/kv"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+const conflict = 0.5
+
+func makeLabels(n int) (_, _ *resource.Resource) {
+	used := map[string]bool{}
+	l1 := make([]kv.KeyValue, n)
+	l2 := make([]kv.KeyValue, n)
+	for i := 0; i < n; i++ {
+		var k string
+		for {
+			k = fmt.Sprint("k", rand.Intn(1000000000))
+			if !used[k] {
+				used[k] = true
+				break
+			}
+		}
+		l1[i] = kv.String(k, fmt.Sprint("v", rand.Intn(1000000000)))
+
+		if rand.Float64() < conflict {
+			l2[i] = l1[i]
+		} else {
+			l2[i] = kv.String(k, fmt.Sprint("v", rand.Intn(1000000000)))
+		}
+
+	}
+	return resource.New(l1...), resource.New(l2...)
+}
+
+func benchmarkMergeResource(b *testing.B, size int) {
+	r1, r2 := makeLabels(size)
+
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		_ = resource.Merge(r1, r2)
+	}
+}
+
+func BenchmarkMergeResource_1(b *testing.B) {
+	benchmarkMergeResource(b, 1)
+}
+func BenchmarkMergeResource_2(b *testing.B) {
+	benchmarkMergeResource(b, 2)
+}
+func BenchmarkMergeResource_3(b *testing.B) {
+	benchmarkMergeResource(b, 3)
+}
+func BenchmarkMergeResource_4(b *testing.B) {
+	benchmarkMergeResource(b, 4)
+}
+func BenchmarkMergeResource_6(b *testing.B) {
+	benchmarkMergeResource(b, 6)
+}
+func BenchmarkMergeResource_8(b *testing.B) {
+	benchmarkMergeResource(b, 8)
+}
+func BenchmarkMergeResource_16(b *testing.B) {
+	benchmarkMergeResource(b, 16)
+}