Remove Sortable

attribute/set.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"reflect"
 	"sort"
-	"sync"
 )
 
 type (
@@ -56,12 +55,6 @@ var (
 			iface: [0]KeyValue{},
 		},
 	}
-
-	// sortables is a pool of Sortables used to create Sets with a user does
-	// not provide one.
-	sortables = sync.Pool{
-		New: func() interface{} { return new(Sortable) },
-	}
 )
 
 // EmptySet returns a reference to a Set with no elements.
@@ -191,22 +184,20 @@ func NewSet(kvs ...KeyValue) Set {
 	if len(kvs) == 0 {
 		return empty()
 	}
-	srt := sortables.Get().(*Sortable)
-	s, _ := NewSetWithSortableFiltered(kvs, srt, nil)
-	sortables.Put(srt)
+	s, _ := NewSetWithSortableFiltered(kvs, nil, nil)
 	return s
 }
 
 // NewSetWithSortable returns a new Set. See the documentation for
 // NewSetWithSortableFiltered for more details.
 //
 // This call includes a Sortable option as a memory optimization.
-func NewSetWithSortable(kvs []KeyValue, tmp *Sortable) Set {
+func NewSetWithSortable(kvs []KeyValue, _ *Sortable) Set {
 	// Check for empty set.
 	if len(kvs) == 0 {
 		return empty()
 	}
-	s, _ := NewSetWithSortableFiltered(kvs, tmp, nil)
+	s, _ := NewSetWithSortableFiltered(kvs, nil, nil)
 	return s
 }
 
@@ -220,9 +211,7 @@ func NewSetWithFiltered(kvs []KeyValue, filter Filter) (Set, []KeyValue) {
 	if len(kvs) == 0 {
 		return empty(), nil
 	}
-	srt := sortables.Get().(*Sortable)
-	s, filtered := NewSetWithSortableFiltered(kvs, srt, filter)
-	sortables.Put(srt)
+	s, filtered := NewSetWithSortableFiltered(kvs, nil, filter)
 	return s, filtered
 }
 
@@ -249,19 +238,15 @@ func NewSetWithFiltered(kvs []KeyValue, filter Filter) (Set, []KeyValue) {
 //
 // The second []KeyValue return value is a list of attributes that were
 // excluded by the Filter (if non-nil).
-func NewSetWithSortableFiltered(kvs []KeyValue, tmp *Sortable, filter Filter) (Set, []KeyValue) {
+func NewSetWithSortableFiltered(kvs []KeyValue, _ *Sortable, filter Filter) (Set, []KeyValue) {
 	// Check for empty set.
 	if len(kvs) == 0 {
 		return empty(), nil
 	}
 
-	*tmp = kvs
-
 	// Stable sort so the following de-duplication can implement
 	// last-value-wins semantics.
-	sort.Stable(tmp)
-
-	*tmp = nil
+	sliceSortStable(kvs)
 
 	position := len(kvs) - 1
 	offset := position - 1

attribute/set_test.go

@@ -225,3 +225,18 @@ func args(m reflect.Method) []reflect.Value {
 	}
 	return out
 }
+
+var (
+	sinkSet   attribute.Set
+	sinkAttrs []attribute.KeyValue
+)
+
+func BenchmarkNewSetWithSortableFiltered(b *testing.B) {
+	attrs := []attribute.KeyValue{attribute.Int("C", 3), attribute.Int("A", 1), attribute.Int("B", 2)}
+	srt := new(attribute.Sortable)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		sinkSet, sinkAttrs = attribute.NewSetWithSortableFiltered(attrs, srt, nil)
+	}
+}

attribute/sort.go

@@ -0,0 +1,11 @@
+//go:build !go1.21
+
+package attribute
+
+import "sort"
+
+func sliceSortStable(kvs []KeyValue) {
+	sort.SliceStable(kvs, func(i, j int) bool {
+		return kvs[i].Key < kvs[j].Key
+	})
+}

attribute/sort_1.21.go

@@ -0,0 +1,17 @@
+//go:build go1.21
+
+package attribute
+
+import "slices"
+
+func sliceSortStable(kvs []KeyValue) {
+	slices.SortStableFunc(kvs, func(a, b KeyValue) int {
+		if a.Key == b.Key {
+			return 0
+		}
+		if a.Key < b.Key {
+			return -1
+		}
+		return 1
+	})
+}