Use slices.SortFunc in OpenCensus bridge instead of sort package (#4990)

bridge/opencensus/internal/ocmetric/metric.go

@@ -4,11 +4,12 @@
 package internal // import "go.opentelemetry.io/otel/bridge/opencensus/internal/ocmetric"
 
 import (
+	"cmp"
 	"errors"
 	"fmt"
 	"math"
 	"reflect"
-	"sort"
+	"slices"
 	"strconv"
 
 	ocmetricdata "go.opencensus.io/metric/metricdata"
@@ -200,8 +201,9 @@ func convertExemplar(ocExemplar *ocmetricdata.Exemplar) (metricdata.Exemplar[flo
 			exemplar.FilteredAttributes = append(exemplar.FilteredAttributes, convertKV(k, v))
 		}
 	}
-	sortable := attribute.Sortable(exemplar.FilteredAttributes)
-	sort.Sort(&sortable)
+	slices.SortFunc(exemplar.FilteredAttributes, func(a, b attribute.KeyValue) int {
+		return cmp.Compare(a.Key, b.Key)
+	})
 	return exemplar, err
 }
 
@@ -377,18 +379,12 @@ func convertQuantiles(snapshot ocmetricdata.Snapshot) []metricdata.QuantileValue
 			Value:    value,
 		})
 	}
-	sort.Sort(byQuantile(quantileValues))
+	slices.SortFunc(quantileValues, func(a, b metricdata.QuantileValue) int {
+		return cmp.Compare(a.Quantile, b.Quantile)
+	})
 	return quantileValues
 }
 
-// byQuantile implements sort.Interface for []metricdata.QuantileValue
-// based on the Quantile field.
-type byQuantile []metricdata.QuantileValue
-
-func (a byQuantile) Len() int           { return len(a) }
-func (a byQuantile) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-func (a byQuantile) Less(i, j int) bool { return a[i].Quantile < a[j].Quantile }
-
 // convertAttrs converts from OpenCensus attribute keys and values to an
 // OpenTelemetry attribute Set.
 func convertAttrs(keys []ocmetricdata.LabelKey, values []ocmetricdata.LabelValue) (attribute.Set, error) {

bridge/opencensus/internal/ocmetric/metric_test.go

@@ -7,7 +7,9 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"math/rand"
 	"reflect"
+	"strconv"
 	"testing"
 	"time"
 
@@ -1168,3 +1170,57 @@ func TestConvertKV(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkConvertExemplar(b *testing.B) {
+	const attchmentsN = 10
+	data := make([]*ocmetricdata.Exemplar, b.N)
+	for i := range data {
+		a := make(ocmetricdata.Attachments, attchmentsN)
+		for j := 0; j < attchmentsN; j++ {
+			a[strconv.Itoa(j)] = rand.Int63()
+		}
+		data[i] = &ocmetricdata.Exemplar{
+			Value:       rand.NormFloat64(),
+			Timestamp:   time.Now(),
+			Attachments: a,
+		}
+	}
+
+	var out metricdata.Exemplar[float64]
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		out, _ = convertExemplar(data[n])
+	}
+
+	_ = out
+}
+
+func BenchmarkConvertQuantiles(b *testing.B) {
+	const percentileN = 20
+	data := make([]ocmetricdata.Snapshot, b.N)
+	for i := range data {
+		p := make(map[float64]float64, percentileN)
+		for j := 0; j < percentileN; j++ {
+			v := rand.Float64()
+			for v == 0 {
+				// Convert from [0, 1) interval to (0, 1).
+				v = rand.Float64()
+			}
+			v *= 100 // Convert from (0, 1) interval to (0, 100).
+			p[v] = rand.ExpFloat64()
+		}
+		data[i] = ocmetricdata.Snapshot{Percentiles: p}
+	}
+
+	var out []metricdata.QuantileValue
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		out = convertQuantiles(data[n])
+	}
+
+	_ = out
+}