Utilize the new slices package in sdk/metric (#4982)

sdk/metric/aggregation.go

@@ -17,6 +17,7 @@ package metric // import "go.opentelemetry.io/otel/sdk/metric"
 import (
 	"errors"
 	"fmt"
+	"slices"
 )
 
 // errAgg is wrapped by misconfigured aggregations.
@@ -141,10 +142,8 @@ func (h AggregationExplicitBucketHistogram) err() error {
 
 // copy returns a deep copy of h.
 func (h AggregationExplicitBucketHistogram) copy() Aggregation {
-	b := make([]float64, len(h.Boundaries))
-	copy(b, h.Boundaries)
 	return AggregationExplicitBucketHistogram{
-		Boundaries: b,
+		Boundaries: slices.Clone(h.Boundaries),
 		NoMinMax:   h.NoMinMax,
 	}
 }

sdk/metric/exemplar.go

@@ -17,6 +17,7 @@ package metric // import "go.opentelemetry.io/otel/sdk/metric"
 import (
 	"os"
 	"runtime"
+	"slices"
 
 	"go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 	"go.opentelemetry.io/otel/sdk/metric/internal/x"
@@ -40,8 +41,7 @@ func reservoirFunc[N int64 | float64](agg Aggregation) func() exemplar.Reservoir
 		// use AlignedHistogramBucketExemplarReservoir.
 		a, ok := agg.(AggregationExplicitBucketHistogram)
 		if ok && len(a.Boundaries) > 0 {
-			cp := make([]float64, len(a.Boundaries))
+			cp := slices.Clone(a.Boundaries)
-			copy(cp, a.Boundaries)
 			return func() exemplar.Reservoir[N] {
 				bounds := cp
 				return exemplar.Histogram[N](bounds)

sdk/metric/internal/aggregate/histogram.go

@@ -16,6 +16,7 @@ package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggreg
 
 import (
 	"context"
+	"slices"
 	"sort"
 	"sync"
 	"time"
@@ -68,9 +69,8 @@ func newHistValues[N int64 | float64](bounds []float64, noSum bool, limit int, r
 	// passed boundaries is ultimately this type's responsibility. Make a copy
 	// here so we can always guarantee this. Or, in the case of failure, have
 	// complete control over the fix.
-	b := make([]float64, len(bounds))
+	b := slices.Clone(bounds)
-	copy(b, bounds)
+	slices.Sort(b)
-	sort.Float64s(b)
 	return &histValues[N]{
 		noSum:  noSum,
 		bounds: b,
@@ -150,8 +150,7 @@ func (s *histogram[N]) delta(dest *metricdata.Aggregation) int {
 	defer s.valuesMu.Unlock()
 
 	// Do not allow modification of our copy of bounds.
-	bounds := make([]float64, len(s.bounds))
+	bounds := slices.Clone(s.bounds)
-	copy(bounds, s.bounds)
 
 	n := len(s.values)
 	hDPts := reset(h.DataPoints, n, n)
@@ -201,28 +200,25 @@ func (s *histogram[N]) cumulative(dest *metricdata.Aggregation) int {
 	defer s.valuesMu.Unlock()
 
 	// Do not allow modification of our copy of bounds.
-	bounds := make([]float64, len(s.bounds))
+	bounds := slices.Clone(s.bounds)
-	copy(bounds, s.bounds)
 
 	n := len(s.values)
 	hDPts := reset(h.DataPoints, n, n)
 
 	var i int
 	for a, b := range s.values {
-		// The HistogramDataPoint field values returned need to be copies of
-		// the buckets value as we will keep updating them.
-		//
-		// TODO (#3047): Making copies for bounds and counts incurs a large
-		// memory allocation footprint. Alternatives should be explored.
-		counts := make([]uint64, len(b.counts))
-		copy(counts, b.counts)
-
 		hDPts[i].Attributes = a
 		hDPts[i].StartTime = s.start
 		hDPts[i].Time = t
 		hDPts[i].Count = b.count
 		hDPts[i].Bounds = bounds
-		hDPts[i].BucketCounts = counts
+
+		// The HistogramDataPoint field values returned need to be copies of
+		// the buckets value as we will keep updating them.
+		//
+		// TODO (#3047): Making copies for bounds and counts incurs a large
+		// memory allocation footprint. Alternatives should be explored.
+		hDPts[i].BucketCounts = slices.Clone(b.counts)
 
 		if !s.noSum {
 			hDPts[i].Sum = b.total

sdk/metric/internal/exemplar/hist.go

@@ -16,6 +16,7 @@ package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exempla
 
 import (
 	"context"
+	"slices"
 	"sort"
 	"time"
 
@@ -28,7 +29,7 @@ import (
 //
 // The passed bounds will be sorted by this function.
 func Histogram[N int64 | float64](bounds []float64) Reservoir[N] {
-	sort.Float64s(bounds)
+	slices.Sort(bounds)
 	return &histRes[N]{
 		bounds:  bounds,
 		storage: newStorage[N](len(bounds) + 1),

sdk/metric/internal/exemplar/rand_test.go

@@ -17,7 +17,7 @@ package exemplar
 import (
 	"context"
 	"math"
-	"sort"
+	"slices"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -43,7 +43,7 @@ func TestFixedSizeSamplingCorrectness(t *testing.T) {
 		data[i] = (-1.0 / intensity) * math.Log(random())
 	}
 	// Sort to test position bias.
-	sort.Float64s(data)
+	slices.Sort(data)
 
 	r := FixedSize[float64](sampleSize)
 	for _, value := range data {