Merge pull request #125140 from huww98/sets-slices-sort

util/sets: simplify List() by using slices.Sort

staging/src/k8s.io/apimachinery/pkg/util/sets/set.go

@@ -18,7 +18,7 @@ package sets
 
 import (
 	"cmp"
-	"sort"
+	"slices"
 )
 
 // Set is a set of the same type elements, implemented via map[comparable]struct{} for minimal memory consumption.
@@ -188,22 +188,13 @@ func (s1 Set[T]) Equal(s2 Set[T]) bool {
 	return len(s1) == len(s2) && s1.IsSuperset(s2)
 }
 
-type sortableSliceOfGeneric[T cmp.Ordered] []T
-
-func (g sortableSliceOfGeneric[T]) Len() int           { return len(g) }
-func (g sortableSliceOfGeneric[T]) Less(i, j int) bool { return less[T](g[i], g[j]) }
-func (g sortableSliceOfGeneric[T]) Swap(i, j int)      { g[i], g[j] = g[j], g[i] }
-
 // List returns the contents as a sorted T slice.
 //
 // This is a separate function and not a method because not all types supported
 // by Generic are ordered and only those can be sorted.
 func List[T cmp.Ordered](s Set[T]) []T {
-	res := make(sortableSliceOfGeneric[T], 0, len(s))
-	for key := range s {
-		res = append(res, key)
-	}
-	sort.Sort(res)
+	res := s.UnsortedList()
+	slices.Sort(res)
 	return res
 }
 
@@ -230,7 +221,3 @@ func (s Set[T]) PopAny() (T, bool) {
 func (s Set[T]) Len() int {
 	return len(s)
 }
-
-func less[T cmp.Ordered](lhs, rhs T) bool {
-	return lhs < rhs
-}

staging/src/k8s.io/apimachinery/pkg/util/sets/set_generic_test.go

@@ -356,3 +356,20 @@ func TestIntersection(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkListSmall(b *testing.B) {
+	s := sets.New("a", "b", "c", "d", "e", "f", "g", "h", "i", "j")
+	for b.Loop() {
+		sets.List(s)
+	}
+}
+
+func BenchmarkListLarge(b *testing.B) {
+	s := make(sets.Set[int], 12345)
+	for i := range 12345 {
+		s.Insert(i * 7)
+	}
+	for b.Loop() {
+		sets.List(s)
+	}
+}