cleanup sort implementation

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal/BUILD

@@ -8,7 +8,6 @@ go_library(
         "gvkparser.go",
         "managedfields.go",
         "pathelement.go",
-        "sort.go",
         "typeconverter.go",
         "versionconverter.go",
     ],

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal/managedfields.go

@@ -150,24 +150,23 @@ func encodeManagedFields(managedFields fieldpath.ManagedFields) (encodedManagedF
 }
 
 func sortEncodedManagedFields(encodedManagedFields []metav1.ManagedFieldsEntry) (sortedManagedFields []metav1.ManagedFieldsEntry, err error) {
-	operation := func(p, q metav1.ManagedFieldsEntry) bool {
-		return p.Operation < q.Operation
-	}
-	timestamp := func(p, q metav1.ManagedFieldsEntry) bool {
+	sort.Slice(encodedManagedFields, func(i, j int) bool {
+		p, q := encodedManagedFields[i], encodedManagedFields[j]
+
+		if p.Operation != q.Operation {
+			return p.Operation < q.Operation
+		}
+
 		if p.Time == nil || q.Time == nil {
 			return false
 		}
-		return q.Time.Before(p.Time)
-	}
-	manager := func(p, q metav1.ManagedFieldsEntry) bool {
+		if !p.Time.Equal(q.Time) {
+			return q.Time.Before(p.Time)
+		}
+
 		return p.Manager < q.Manager
-	}
+	})
 
-	sorter := &managedFieldsSorter{
-		less: []managedFieldsLessFunc{operation, timestamp, manager},
-	}
-
-	sorter.Sort(encodedManagedFields)
 	return encodedManagedFields, nil
 }
 

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal/sort.go

@@ -1,61 +0,0 @@
-/*
-Copyright 2019 The Kubernetes 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 internal
-
-import (
-	"sort"
-
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-)
-
-type managedFieldsLessFunc func(p, q metav1.ManagedFieldsEntry) bool
-
-type managedFieldsSorter struct {
-	fields []metav1.ManagedFieldsEntry
-	less   []managedFieldsLessFunc
-}
-
-func (s *managedFieldsSorter) Sort(fields []metav1.ManagedFieldsEntry) {
-	s.fields = fields
-	sort.Sort(s)
-}
-
-// Len is the amount of managedFields to sort
-func (s *managedFieldsSorter) Len() int {
-	return len(s.fields)
-}
-
-// Swap is part of sort.Interface.
-func (s *managedFieldsSorter) Swap(p, q int) {
-	s.fields[p], s.fields[q] = s.fields[q], s.fields[p]
-}
-
-// Less is part of sort.Interface
-func (s *managedFieldsSorter) Less(p, q int) bool {
-	a, b := s.fields[p], s.fields[q]
-	var k int
-	for k = 0; k < len(s.less)-1; k++ {
-		less := s.less[k]
-		switch {
-		case less(a, b):
-			return true
-		case less(b, a):
-			return false
-		}
-	}
-	return s.less[k](a, b)
-}