rebase: update kubernetes to v1.21.2

Updated kubernetes packages to latest release.
resizefs package has been included into k8s.io/mount-utils
package. updated code to use the same.

Updates: #1968

Signed-off-by: Rakshith R <rar@redhat.com>

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/doc.go

@@ -0,0 +1,21 @@
+/*
+Copyright 2018 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 fieldpath defines a way for referencing path elements (e.g., an
+// index in an array, or a key in a map). It provides types for arranging these
+// into paths for referencing nested fields, and for grouping those into sets,
+// for referencing multiple nested fields.
+package fieldpath

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/element.go

@@ -0,0 +1,317 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// PathElement describes how to select a child field given a containing object.
+type PathElement struct {
+	// Exactly one of the following fields should be non-nil.
+
+	// FieldName selects a single field from a map (reminder: this is also
+	// how structs are represented). The containing object must be a map.
+	FieldName *string
+
+	// Key selects the list element which has fields matching those given.
+	// The containing object must be an associative list with map typed
+	// elements. They are sorted alphabetically.
+	Key *value.FieldList
+
+	// Value selects the list element with the given value. The containing
+	// object must be an associative list with a primitive typed element
+	// (i.e., a set).
+	Value *value.Value
+
+	// Index selects a list element by its index number. The containing
+	// object must be an atomic list.
+	Index *int
+}
+
+// Less provides an order for path elements.
+func (e PathElement) Less(rhs PathElement) bool {
+	return e.Compare(rhs) < 0
+}
+
+// Compare provides an order for path elements.
+func (e PathElement) Compare(rhs PathElement) int {
+	if e.FieldName != nil {
+		if rhs.FieldName == nil {
+			return -1
+		}
+		return strings.Compare(*e.FieldName, *rhs.FieldName)
+	} else if rhs.FieldName != nil {
+		return 1
+	}
+
+	if e.Key != nil {
+		if rhs.Key == nil {
+			return -1
+		}
+		return e.Key.Compare(*rhs.Key)
+	} else if rhs.Key != nil {
+		return 1
+	}
+
+	if e.Value != nil {
+		if rhs.Value == nil {
+			return -1
+		}
+		return value.Compare(*e.Value, *rhs.Value)
+	} else if rhs.Value != nil {
+		return 1
+	}
+
+	if e.Index != nil {
+		if rhs.Index == nil {
+			return -1
+		}
+		if *e.Index < *rhs.Index {
+			return -1
+		} else if *e.Index == *rhs.Index {
+			return 0
+		}
+		return 1
+	} else if rhs.Index != nil {
+		return 1
+	}
+
+	return 0
+}
+
+// Equals returns true if both path elements are equal.
+func (e PathElement) Equals(rhs PathElement) bool {
+	if e.FieldName != nil {
+		if rhs.FieldName == nil {
+			return false
+		}
+		return *e.FieldName == *rhs.FieldName
+	} else if rhs.FieldName != nil {
+		return false
+	}
+	if e.Key != nil {
+		if rhs.Key == nil {
+			return false
+		}
+		return e.Key.Equals(*rhs.Key)
+	} else if rhs.Key != nil {
+		return false
+	}
+	if e.Value != nil {
+		if rhs.Value == nil {
+			return false
+		}
+		return value.Equals(*e.Value, *rhs.Value)
+	} else if rhs.Value != nil {
+		return false
+	}
+	if e.Index != nil {
+		if rhs.Index == nil {
+			return false
+		}
+		return *e.Index == *rhs.Index
+	} else if rhs.Index != nil {
+		return false
+	}
+	return true
+}
+
+// String presents the path element as a human-readable string.
+func (e PathElement) String() string {
+	switch {
+	case e.FieldName != nil:
+		return "." + *e.FieldName
+	case e.Key != nil:
+		strs := make([]string, len(*e.Key))
+		for i, k := range *e.Key {
+			strs[i] = fmt.Sprintf("%v=%v", k.Name, value.ToString(k.Value))
+		}
+		// Keys are supposed to be sorted.
+		return "[" + strings.Join(strs, ",") + "]"
+	case e.Value != nil:
+		return fmt.Sprintf("[=%v]", value.ToString(*e.Value))
+	case e.Index != nil:
+		return fmt.Sprintf("[%v]", *e.Index)
+	default:
+		return "{{invalid path element}}"
+	}
+}
+
+// KeyByFields is a helper function which constructs a key for an associative
+// list type. `nameValues` must have an even number of entries, alternating
+// names (type must be string) with values (type must be value.Value). If these
+// conditions are not met, KeyByFields will panic--it's intended for static
+// construction and shouldn't have user-produced values passed to it.
+func KeyByFields(nameValues ...interface{}) *value.FieldList {
+	if len(nameValues)%2 != 0 {
+		panic("must have a value for every name")
+	}
+	out := value.FieldList{}
+	for i := 0; i < len(nameValues)-1; i += 2 {
+		out = append(out, value.Field{Name: nameValues[i].(string), Value: value.NewValueInterface(nameValues[i+1])})
+	}
+	out.Sort()
+	return &out
+}
+
+// PathElementSet is a set of path elements.
+// TODO: serialize as a list.
+type PathElementSet struct {
+	members sortedPathElements
+}
+
+func MakePathElementSet(size int) PathElementSet {
+	return PathElementSet{
+		members: make(sortedPathElements, 0, size),
+	}
+}
+
+type sortedPathElements []PathElement
+
+// Implement the sort interface; this would permit bulk creation, which would
+// be faster than doing it one at a time via Insert.
+func (spe sortedPathElements) Len() int           { return len(spe) }
+func (spe sortedPathElements) Less(i, j int) bool { return spe[i].Less(spe[j]) }
+func (spe sortedPathElements) Swap(i, j int)      { spe[i], spe[j] = spe[j], spe[i] }
+
+// Insert adds pe to the set.
+func (s *PathElementSet) Insert(pe PathElement) {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].Less(pe)
+	})
+	if loc == len(s.members) {
+		s.members = append(s.members, pe)
+		return
+	}
+	if s.members[loc].Equals(pe) {
+		return
+	}
+	s.members = append(s.members, PathElement{})
+	copy(s.members[loc+1:], s.members[loc:])
+	s.members[loc] = pe
+}
+
+// Union returns a set containing elements that appear in either s or s2.
+func (s *PathElementSet) Union(s2 *PathElementSet) *PathElementSet {
+	out := &PathElementSet{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.members) {
+		if s.members[i].Less(s2.members[j]) {
+			out.members = append(out.members, s.members[i])
+			i++
+		} else {
+			out.members = append(out.members, s2.members[j])
+			if !s2.members[j].Less(s.members[i]) {
+				i++
+			}
+			j++
+		}
+	}
+
+	if i < len(s.members) {
+		out.members = append(out.members, s.members[i:]...)
+	}
+	if j < len(s2.members) {
+		out.members = append(out.members, s2.members[j:]...)
+	}
+	return out
+}
+
+// Intersection returns a set containing elements which appear in both s and s2.
+func (s *PathElementSet) Intersection(s2 *PathElementSet) *PathElementSet {
+	out := &PathElementSet{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.members) {
+		if s.members[i].Less(s2.members[j]) {
+			i++
+		} else {
+			if !s2.members[j].Less(s.members[i]) {
+				out.members = append(out.members, s.members[i])
+				i++
+			}
+			j++
+		}
+	}
+
+	return out
+}
+
+// Difference returns a set containing elements which appear in s but not in s2.
+func (s *PathElementSet) Difference(s2 *PathElementSet) *PathElementSet {
+	out := &PathElementSet{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.members) {
+		if s.members[i].Less(s2.members[j]) {
+			out.members = append(out.members, s.members[i])
+			i++
+		} else {
+			if !s2.members[j].Less(s.members[i]) {
+				i++
+			}
+			j++
+		}
+	}
+	if i < len(s.members) {
+		out.members = append(out.members, s.members[i:]...)
+	}
+	return out
+}
+
+// Size retuns the number of elements in the set.
+func (s *PathElementSet) Size() int { return len(s.members) }
+
+// Has returns true if pe is a member of the set.
+func (s *PathElementSet) Has(pe PathElement) bool {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].Less(pe)
+	})
+	if loc == len(s.members) {
+		return false
+	}
+	if s.members[loc].Equals(pe) {
+		return true
+	}
+	return false
+}
+
+// Equals returns true if s and s2 have exactly the same members.
+func (s *PathElementSet) Equals(s2 *PathElementSet) bool {
+	if len(s.members) != len(s2.members) {
+		return false
+	}
+	for k := range s.members {
+		if !s.members[k].Equals(s2.members[k]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Iterate calls f for each PathElement in the set. The order is deterministic.
+func (s *PathElementSet) Iterate(f func(PathElement)) {
+	for _, pe := range s.members {
+		f(pe)
+	}
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/fromvalue.go

@@ -0,0 +1,134 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// SetFromValue creates a set containing every leaf field mentioned in v.
+func SetFromValue(v value.Value) *Set {
+	s := NewSet()
+
+	w := objectWalker{
+		path:      Path{},
+		value:     v,
+		allocator: value.NewFreelistAllocator(),
+		do:        func(p Path) { s.Insert(p) },
+	}
+
+	w.walk()
+	return s
+}
+
+type objectWalker struct {
+	path      Path
+	value     value.Value
+	allocator value.Allocator
+
+	do func(Path)
+}
+
+func (w *objectWalker) walk() {
+	switch {
+	case w.value.IsNull():
+	case w.value.IsFloat():
+	case w.value.IsInt():
+	case w.value.IsString():
+	case w.value.IsBool():
+		// All leaf fields handled the same way (after the switch
+		// statement).
+
+	// Descend
+	case w.value.IsList():
+		// If the list were atomic, we'd break here, but we don't have
+		// a schema, so we can't tell.
+		l := w.value.AsListUsing(w.allocator)
+		defer w.allocator.Free(l)
+		iter := l.RangeUsing(w.allocator)
+		defer w.allocator.Free(iter)
+		for iter.Next() {
+			i, value := iter.Item()
+			w2 := *w
+			w2.path = append(w.path, w.GuessBestListPathElement(i, value))
+			w2.value = value
+			w2.walk()
+		}
+		return
+	case w.value.IsMap():
+		// If the map/struct were atomic, we'd break here, but we don't
+		// have a schema, so we can't tell.
+
+		m := w.value.AsMapUsing(w.allocator)
+		defer w.allocator.Free(m)
+		m.IterateUsing(w.allocator, func(k string, val value.Value) bool {
+			w2 := *w
+			w2.path = append(w.path, PathElement{FieldName: &k})
+			w2.value = val
+			w2.walk()
+			return true
+		})
+		return
+	}
+
+	// Leaf fields get added to the set.
+	if len(w.path) > 0 {
+		w.do(w.path)
+	}
+}
+
+// AssociativeListCandidateFieldNames lists the field names which are
+// considered keys if found in a list element.
+var AssociativeListCandidateFieldNames = []string{
+	"key",
+	"id",
+	"name",
+}
+
+// GuessBestListPathElement guesses whether item is an associative list
+// element, which should be referenced by key(s), or if it is not and therefore
+// referencing by index is acceptable. Currently this is done by checking
+// whether item has any of the fields listed in
+// AssociativeListCandidateFieldNames which have scalar values.
+func (w *objectWalker) GuessBestListPathElement(index int, item value.Value) PathElement {
+	if !item.IsMap() {
+		// Non map items could be parts of sets or regular "atomic"
+		// lists. We won't try to guess whether something should be a
+		// set or not.
+		return PathElement{Index: &index}
+	}
+
+	m := item.AsMapUsing(w.allocator)
+	defer w.allocator.Free(m)
+	var keys value.FieldList
+	for _, name := range AssociativeListCandidateFieldNames {
+		f, ok := m.Get(name)
+		if !ok {
+			continue
+		}
+		// only accept primitive/scalar types as keys.
+		if f.IsNull() || f.IsMap() || f.IsList() {
+			continue
+		}
+		keys = append(keys, value.Field{Name: name, Value: f})
+	}
+	if len(keys) > 0 {
+		keys.Sort()
+		return PathElement{Key: &keys}
+	}
+	return PathElement{Index: &index}
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/managers.go

@@ -0,0 +1,144 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"fmt"
+	"strings"
+)
+
+// APIVersion describes the version of an object or of a fieldset.
+type APIVersion string
+
+type VersionedSet interface {
+	Set() *Set
+	APIVersion() APIVersion
+	Applied() bool
+}
+
+// VersionedSet associates a version to a set.
+type versionedSet struct {
+	set        *Set
+	apiVersion APIVersion
+	applied    bool
+}
+
+func NewVersionedSet(set *Set, apiVersion APIVersion, applied bool) VersionedSet {
+	return versionedSet{
+		set:        set,
+		apiVersion: apiVersion,
+		applied:    applied,
+	}
+}
+
+func (v versionedSet) Set() *Set {
+	return v.set
+}
+
+func (v versionedSet) APIVersion() APIVersion {
+	return v.apiVersion
+}
+
+func (v versionedSet) Applied() bool {
+	return v.applied
+}
+
+// ManagedFields is a map from manager to VersionedSet (what they own in
+// what version).
+type ManagedFields map[string]VersionedSet
+
+// Equals returns true if the two managedfields are the same, false
+// otherwise.
+func (lhs ManagedFields) Equals(rhs ManagedFields) bool {
+	if len(lhs) != len(rhs) {
+		return false
+	}
+
+	for manager, left := range lhs {
+		right, ok := rhs[manager]
+		if !ok {
+			return false
+		}
+		if left.APIVersion() != right.APIVersion() || left.Applied() != right.Applied() {
+			return false
+		}
+		if !left.Set().Equals(right.Set()) {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy the list, this is mostly a shallow copy.
+func (lhs ManagedFields) Copy() ManagedFields {
+	copy := ManagedFields{}
+	for manager, set := range lhs {
+		copy[manager] = set
+	}
+	return copy
+}
+
+// Difference returns a symmetric difference between two Managers. If a
+// given user's entry has version X in lhs and version Y in rhs, then
+// the return value for that user will be from rhs. If the difference for
+// a user is an empty set, that user will not be inserted in the map.
+func (lhs ManagedFields) Difference(rhs ManagedFields) ManagedFields {
+	diff := ManagedFields{}
+
+	for manager, left := range lhs {
+		right, ok := rhs[manager]
+		if !ok {
+			if !left.Set().Empty() {
+				diff[manager] = left
+			}
+			continue
+		}
+
+		// If we have sets in both but their version
+		// differs, we don't even diff and keep the
+		// entire thing.
+		if left.APIVersion() != right.APIVersion() {
+			diff[manager] = right
+			continue
+		}
+
+		newSet := left.Set().Difference(right.Set()).Union(right.Set().Difference(left.Set()))
+		if !newSet.Empty() {
+			diff[manager] = NewVersionedSet(newSet, right.APIVersion(), false)
+		}
+	}
+
+	for manager, set := range rhs {
+		if _, ok := lhs[manager]; ok {
+			// Already done
+			continue
+		}
+		if !set.Set().Empty() {
+			diff[manager] = set
+		}
+	}
+
+	return diff
+}
+
+func (lhs ManagedFields) String() string {
+	s := strings.Builder{}
+	for k, v := range lhs {
+		fmt.Fprintf(&s, "%s:\n", k)
+		fmt.Fprintf(&s, "- Applied: %v\n", v.Applied())
+		fmt.Fprintf(&s, "- APIVersion: %v\n", v.APIVersion())
+		fmt.Fprintf(&s, "- Set: %v\n", v.Set())
+	}
+	return s.String()
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/path.go

@@ -0,0 +1,118 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// Path describes how to select a potentially deeply-nested child field given a
+// containing object.
+type Path []PathElement
+
+func (fp Path) String() string {
+	strs := make([]string, len(fp))
+	for i := range fp {
+		strs[i] = fp[i].String()
+	}
+	return strings.Join(strs, "")
+}
+
+// Equals returns true if the two paths are equivalent.
+func (fp Path) Equals(fp2 Path) bool {
+	if len(fp) != len(fp2) {
+		return false
+	}
+	for i := range fp {
+		if !fp[i].Equals(fp2[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Less provides a lexical order for Paths.
+func (fp Path) Compare(rhs Path) int {
+	i := 0
+	for {
+		if i >= len(fp) && i >= len(rhs) {
+			// Paths are the same length and all items are equal.
+			return 0
+		}
+		if i >= len(fp) {
+			// LHS is shorter.
+			return -1
+		}
+		if i >= len(rhs) {
+			// RHS is shorter.
+			return 1
+		}
+		if c := fp[i].Compare(rhs[i]); c != 0 {
+			return c
+		}
+		// The items are equal; continue.
+		i++
+	}
+}
+
+func (fp Path) Copy() Path {
+	new := make(Path, len(fp))
+	copy(new, fp)
+	return new
+}
+
+// MakePath constructs a Path. The parts may be PathElements, ints, strings.
+func MakePath(parts ...interface{}) (Path, error) {
+	var fp Path
+	for _, p := range parts {
+		switch t := p.(type) {
+		case PathElement:
+			fp = append(fp, t)
+		case int:
+			// TODO: Understand schema and object and convert this to the
+			// FieldSpecifier below if appropriate.
+			fp = append(fp, PathElement{Index: &t})
+		case string:
+			fp = append(fp, PathElement{FieldName: &t})
+		case *value.FieldList:
+			if len(*t) == 0 {
+				return nil, fmt.Errorf("associative list key type path elements must have at least one key (got zero)")
+			}
+			fp = append(fp, PathElement{Key: t})
+		case value.Value:
+			// TODO: understand schema and verify that this is a set type
+			// TODO: make a copy of t
+			fp = append(fp, PathElement{Value: &t})
+		default:
+			return nil, fmt.Errorf("unable to make %#v into a path element", p)
+		}
+	}
+	return fp, nil
+}
+
+// MakePathOrDie panics if parts can't be turned into a path. Good for things
+// that are known at complie time.
+func MakePathOrDie(parts ...interface{}) Path {
+	fp, err := MakePath(parts...)
+	if err != nil {
+		panic(err)
+	}
+	return fp
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/pathelementmap.go

@@ -0,0 +1,85 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"sort"
+
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// PathElementValueMap is a map from PathElement to value.Value.
+//
+// TODO(apelisse): We have multiple very similar implementation of this
+// for PathElementSet and SetNodeMap, so we could probably share the
+// code.
+type PathElementValueMap struct {
+	members sortedPathElementValues
+}
+
+func MakePathElementValueMap(size int) PathElementValueMap {
+	return PathElementValueMap{
+		members: make(sortedPathElementValues, 0, size),
+	}
+}
+
+type pathElementValue struct {
+	PathElement PathElement
+	Value       value.Value
+}
+
+type sortedPathElementValues []pathElementValue
+
+// Implement the sort interface; this would permit bulk creation, which would
+// be faster than doing it one at a time via Insert.
+func (spev sortedPathElementValues) Len() int { return len(spev) }
+func (spev sortedPathElementValues) Less(i, j int) bool {
+	return spev[i].PathElement.Less(spev[j].PathElement)
+}
+func (spev sortedPathElementValues) Swap(i, j int) { spev[i], spev[j] = spev[j], spev[i] }
+
+// Insert adds the pathelement and associated value in the map.
+func (s *PathElementValueMap) Insert(pe PathElement, v value.Value) {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].PathElement.Less(pe)
+	})
+	if loc == len(s.members) {
+		s.members = append(s.members, pathElementValue{pe, v})
+		return
+	}
+	if s.members[loc].PathElement.Equals(pe) {
+		return
+	}
+	s.members = append(s.members, pathElementValue{})
+	copy(s.members[loc+1:], s.members[loc:])
+	s.members[loc] = pathElementValue{pe, v}
+}
+
+// Get retrieves the value associated with the given PathElement from the map.
+// (nil, false) is returned if there is no such PathElement.
+func (s *PathElementValueMap) Get(pe PathElement) (value.Value, bool) {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].PathElement.Less(pe)
+	})
+	if loc == len(s.members) {
+		return nil, false
+	}
+	if s.members[loc].PathElement.Equals(pe) {
+		return s.members[loc].Value, true
+	}
+	return nil, false
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/serialize-pe.go

@@ -0,0 +1,168 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	jsoniter "github.com/json-iterator/go"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+var ErrUnknownPathElementType = errors.New("unknown path element type")
+
+const (
+	// Field indicates that the content of this path element is a field's name
+	peField = "f"
+
+	// Value indicates that the content of this path element is a field's value
+	peValue = "v"
+
+	// Index indicates that the content of this path element is an index in an array
+	peIndex = "i"
+
+	// Key indicates that the content of this path element is a key value map
+	peKey = "k"
+
+	// Separator separates the type of a path element from the contents
+	peSeparator = ":"
+)
+
+var (
+	peFieldSepBytes = []byte(peField + peSeparator)
+	peValueSepBytes = []byte(peValue + peSeparator)
+	peIndexSepBytes = []byte(peIndex + peSeparator)
+	peKeySepBytes   = []byte(peKey + peSeparator)
+	peSepBytes      = []byte(peSeparator)
+)
+
+// DeserializePathElement parses a serialized path element
+func DeserializePathElement(s string) (PathElement, error) {
+	b := []byte(s)
+	if len(b) < 2 {
+		return PathElement{}, errors.New("key must be 2 characters long:")
+	}
+	typeSep, b := b[:2], b[2:]
+	if typeSep[1] != peSepBytes[0] {
+		return PathElement{}, fmt.Errorf("missing colon: %v", s)
+	}
+	switch typeSep[0] {
+	case peFieldSepBytes[0]:
+		// Slice s rather than convert b, to save on
+		// allocations.
+		str := s[2:]
+		return PathElement{
+			FieldName: &str,
+		}, nil
+	case peValueSepBytes[0]:
+		iter := readPool.BorrowIterator(b)
+		defer readPool.ReturnIterator(iter)
+		v, err := value.ReadJSONIter(iter)
+		if err != nil {
+			return PathElement{}, err
+		}
+		return PathElement{Value: &v}, nil
+	case peKeySepBytes[0]:
+		iter := readPool.BorrowIterator(b)
+		defer readPool.ReturnIterator(iter)
+		fields := value.FieldList{}
+
+		iter.ReadObjectCB(func(iter *jsoniter.Iterator, key string) bool {
+			v, err := value.ReadJSONIter(iter)
+			if err != nil {
+				iter.Error = err
+				return false
+			}
+			fields = append(fields, value.Field{Name: key, Value: v})
+			return true
+		})
+		fields.Sort()
+		return PathElement{Key: &fields}, iter.Error
+	case peIndexSepBytes[0]:
+		i, err := strconv.Atoi(s[2:])
+		if err != nil {
+			return PathElement{}, err
+		}
+		return PathElement{
+			Index: &i,
+		}, nil
+	default:
+		return PathElement{}, ErrUnknownPathElementType
+	}
+}
+
+var (
+	readPool  = jsoniter.NewIterator(jsoniter.ConfigCompatibleWithStandardLibrary).Pool()
+	writePool = jsoniter.NewStream(jsoniter.ConfigCompatibleWithStandardLibrary, nil, 1024).Pool()
+)
+
+// SerializePathElement serializes a path element
+func SerializePathElement(pe PathElement) (string, error) {
+	buf := strings.Builder{}
+	err := serializePathElementToWriter(&buf, pe)
+	return buf.String(), err
+}
+
+func serializePathElementToWriter(w io.Writer, pe PathElement) error {
+	stream := writePool.BorrowStream(w)
+	defer writePool.ReturnStream(stream)
+	switch {
+	case pe.FieldName != nil:
+		if _, err := stream.Write(peFieldSepBytes); err != nil {
+			return err
+		}
+		stream.WriteRaw(*pe.FieldName)
+	case pe.Key != nil:
+		if _, err := stream.Write(peKeySepBytes); err != nil {
+			return err
+		}
+		stream.WriteObjectStart()
+
+		for i, field := range *pe.Key {
+			if i > 0 {
+				stream.WriteMore()
+			}
+			stream.WriteObjectField(field.Name)
+			value.WriteJSONStream(field.Value, stream)
+		}
+		stream.WriteObjectEnd()
+	case pe.Value != nil:
+		if _, err := stream.Write(peValueSepBytes); err != nil {
+			return err
+		}
+		value.WriteJSONStream(*pe.Value, stream)
+	case pe.Index != nil:
+		if _, err := stream.Write(peIndexSepBytes); err != nil {
+			return err
+		}
+		stream.WriteInt(*pe.Index)
+	default:
+		return errors.New("invalid PathElement")
+	}
+	b := stream.Buffer()
+	err := stream.Flush()
+	// Help jsoniter manage its buffers--without this, the next
+	// use of the stream is likely to require an allocation. Look
+	// at the jsoniter stream code to understand why. They were probably
+	// optimizing for folks using the buffer directly.
+	stream.SetBuffer(b[:0])
+	return err
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/serialize.go

@@ -0,0 +1,238 @@
+/*
+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 fieldpath
+
+import (
+	"bytes"
+	"io"
+	"unsafe"
+
+	jsoniter "github.com/json-iterator/go"
+)
+
+func (s *Set) ToJSON() ([]byte, error) {
+	buf := bytes.Buffer{}
+	err := s.ToJSONStream(&buf)
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (s *Set) ToJSONStream(w io.Writer) error {
+	stream := writePool.BorrowStream(w)
+	defer writePool.ReturnStream(stream)
+
+	var r reusableBuilder
+
+	stream.WriteObjectStart()
+	err := s.emitContentsV1(false, stream, &r)
+	if err != nil {
+		return err
+	}
+	stream.WriteObjectEnd()
+	return stream.Flush()
+}
+
+func manageMemory(stream *jsoniter.Stream) error {
+	// Help jsoniter manage its buffers--without this, it does a bunch of
+	// alloctaions that are not necessary. They were probably optimizing
+	// for folks using the buffer directly.
+	b := stream.Buffer()
+	if len(b) > 4096 || cap(b)-len(b) < 2048 {
+		if err := stream.Flush(); err != nil {
+			return err
+		}
+		stream.SetBuffer(b[:0])
+	}
+	return nil
+}
+
+type reusableBuilder struct {
+	bytes.Buffer
+}
+
+func (r *reusableBuilder) unsafeString() string {
+	b := r.Bytes()
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+func (r *reusableBuilder) reset() *bytes.Buffer {
+	r.Reset()
+	return &r.Buffer
+}
+
+func (s *Set) emitContentsV1(includeSelf bool, stream *jsoniter.Stream, r *reusableBuilder) error {
+	mi, ci := 0, 0
+	first := true
+	preWrite := func() {
+		if first {
+			first = false
+			return
+		}
+		stream.WriteMore()
+	}
+
+	if includeSelf && !(len(s.Members.members) == 0 && len(s.Children.members) == 0) {
+		preWrite()
+		stream.WriteObjectField(".")
+		stream.WriteEmptyObject()
+	}
+
+	for mi < len(s.Members.members) && ci < len(s.Children.members) {
+		mpe := s.Members.members[mi]
+		cpe := s.Children.members[ci].pathElement
+
+		if c := mpe.Compare(cpe); c < 0 {
+			preWrite()
+			if err := serializePathElementToWriter(r.reset(), mpe); err != nil {
+				return err
+			}
+			stream.WriteObjectField(r.unsafeString())
+			stream.WriteEmptyObject()
+			mi++
+		} else if c > 0 {
+			preWrite()
+			if err := serializePathElementToWriter(r.reset(), cpe); err != nil {
+				return err
+			}
+			stream.WriteObjectField(r.unsafeString())
+			stream.WriteObjectStart()
+			if err := s.Children.members[ci].set.emitContentsV1(false, stream, r); err != nil {
+				return err
+			}
+			stream.WriteObjectEnd()
+			ci++
+		} else {
+			preWrite()
+			if err := serializePathElementToWriter(r.reset(), cpe); err != nil {
+				return err
+			}
+			stream.WriteObjectField(r.unsafeString())
+			stream.WriteObjectStart()
+			if err := s.Children.members[ci].set.emitContentsV1(true, stream, r); err != nil {
+				return err
+			}
+			stream.WriteObjectEnd()
+			mi++
+			ci++
+		}
+	}
+
+	for mi < len(s.Members.members) {
+		mpe := s.Members.members[mi]
+
+		preWrite()
+		if err := serializePathElementToWriter(r.reset(), mpe); err != nil {
+			return err
+		}
+		stream.WriteObjectField(r.unsafeString())
+		stream.WriteEmptyObject()
+		mi++
+	}
+
+	for ci < len(s.Children.members) {
+		cpe := s.Children.members[ci].pathElement
+
+		preWrite()
+		if err := serializePathElementToWriter(r.reset(), cpe); err != nil {
+			return err
+		}
+		stream.WriteObjectField(r.unsafeString())
+		stream.WriteObjectStart()
+		if err := s.Children.members[ci].set.emitContentsV1(false, stream, r); err != nil {
+			return err
+		}
+		stream.WriteObjectEnd()
+		ci++
+	}
+
+	return manageMemory(stream)
+}
+
+// FromJSON clears s and reads a JSON formatted set structure.
+func (s *Set) FromJSON(r io.Reader) error {
+	// The iterator pool is completely useless for memory management, grrr.
+	iter := jsoniter.Parse(jsoniter.ConfigCompatibleWithStandardLibrary, r, 4096)
+
+	found, _ := readIterV1(iter)
+	if found == nil {
+		*s = Set{}
+	} else {
+		*s = *found
+	}
+	return iter.Error
+}
+
+// returns true if this subtree is also (or only) a member of parent; s is nil
+// if there are no further children.
+func readIterV1(iter *jsoniter.Iterator) (children *Set, isMember bool) {
+	iter.ReadMapCB(func(iter *jsoniter.Iterator, key string) bool {
+		if key == "." {
+			isMember = true
+			iter.Skip()
+			return true
+		}
+		pe, err := DeserializePathElement(key)
+		if err == ErrUnknownPathElementType {
+			// Ignore these-- a future version maybe knows what
+			// they are. We drop these completely rather than try
+			// to preserve things we don't understand.
+			iter.Skip()
+			return true
+		} else if err != nil {
+			iter.ReportError("parsing key as path element", err.Error())
+			iter.Skip()
+			return true
+		}
+		grandchildren, childIsMember := readIterV1(iter)
+		if childIsMember {
+			if children == nil {
+				children = &Set{}
+			}
+			m := &children.Members.members
+			// Since we expect that most of the time these will have been
+			// serialized in the right order, we just verify that and append.
+			appendOK := len(*m) == 0 || (*m)[len(*m)-1].Less(pe)
+			if appendOK {
+				*m = append(*m, pe)
+			} else {
+				children.Members.Insert(pe)
+			}
+		}
+		if grandchildren != nil {
+			if children == nil {
+				children = &Set{}
+			}
+			// Since we expect that most of the time these will have been
+			// serialized in the right order, we just verify that and append.
+			m := &children.Children.members
+			appendOK := len(*m) == 0 || (*m)[len(*m)-1].pathElement.Less(pe)
+			if appendOK {
+				*m = append(*m, setNode{pe, grandchildren})
+			} else {
+				*children.Children.Descend(pe) = *grandchildren
+			}
+		}
+		return true
+	})
+	if children == nil {
+		isMember = true
+	}
+
+	return children, isMember
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/fieldpath/set.go

@@ -0,0 +1,505 @@
+/*
+Copyright 2018 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 fieldpath
+
+import (
+	"sort"
+	"strings"
+
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+)
+
+// Set identifies a set of fields.
+type Set struct {
+	// Members lists fields that are part of the set.
+	// TODO: will be serialized as a list of path elements.
+	Members PathElementSet
+
+	// Children lists child fields which themselves have children that are
+	// members of the set. Appearance in this list does not imply membership.
+	// Note: this is a tree, not an arbitrary graph.
+	Children SetNodeMap
+}
+
+// NewSet makes a set from a list of paths.
+func NewSet(paths ...Path) *Set {
+	s := &Set{}
+	for _, p := range paths {
+		s.Insert(p)
+	}
+	return s
+}
+
+// Insert adds the field identified by `p` to the set. Important: parent fields
+// are NOT added to the set; if that is desired, they must be added separately.
+func (s *Set) Insert(p Path) {
+	if len(p) == 0 {
+		// Zero-length path identifies the entire object; we don't
+		// track top-level ownership.
+		return
+	}
+	for {
+		if len(p) == 1 {
+			s.Members.Insert(p[0])
+			return
+		}
+		s = s.Children.Descend(p[0])
+		p = p[1:]
+	}
+}
+
+// Union returns a Set containing elements which appear in either s or s2.
+func (s *Set) Union(s2 *Set) *Set {
+	return &Set{
+		Members:  *s.Members.Union(&s2.Members),
+		Children: *s.Children.Union(&s2.Children),
+	}
+}
+
+// Intersection returns a Set containing leaf elements which appear in both s
+// and s2. Intersection can be constructed from Union and Difference operations
+// (example in the tests) but it's much faster to do it in one pass.
+func (s *Set) Intersection(s2 *Set) *Set {
+	return &Set{
+		Members:  *s.Members.Intersection(&s2.Members),
+		Children: *s.Children.Intersection(&s2.Children),
+	}
+}
+
+// Difference returns a Set containing elements which:
+// * appear in s
+// * do not appear in s2
+//
+// In other words, for leaf fields, this acts like a regular set difference
+// operation. When non leaf fields are compared with leaf fields ("parents"
+// which contain "children"), the effect is:
+// * parent - child = parent
+// * child - parent = {empty set}
+func (s *Set) Difference(s2 *Set) *Set {
+	return &Set{
+		Members:  *s.Members.Difference(&s2.Members),
+		Children: *s.Children.Difference(s2),
+	}
+}
+
+// RecursiveDifference returns a Set containing elements which:
+// * appear in s
+// * do not appear in s2
+//
+// Compared to a regular difference,
+// this removes every field **and its children** from s that is contained in s2.
+//
+// For example, with s containing `a.b.c` and s2 containing `a.b`,
+// a RecursiveDifference will result in `a`, as the entire node `a.b` gets removed.
+func (s *Set) RecursiveDifference(s2 *Set) *Set {
+	return &Set{
+		Members:  *s.Members.Difference(&s2.Members),
+		Children: *s.Children.RecursiveDifference(s2),
+	}
+}
+
+// EnsureNamedFieldsAreMembers returns a Set that contains all the
+// fields in s, as well as all the named fields that are typically not
+// included. For example, a set made of "a.b.c" will end-up also owning
+// "a" if it's a named fields but not "a.b" if it's a map.
+func (s *Set) EnsureNamedFieldsAreMembers(sc *schema.Schema, tr schema.TypeRef) *Set {
+	members := PathElementSet{
+		members: make(sortedPathElements, 0, s.Members.Size()+len(s.Children.members)),
+	}
+	atom, _ := sc.Resolve(tr)
+	members.members = append(members.members, s.Members.members...)
+	for _, node := range s.Children.members {
+		// Only insert named fields.
+		if node.pathElement.FieldName != nil && atom.Map != nil {
+			if _, has := atom.Map.FindField(*node.pathElement.FieldName); has {
+				members.Insert(node.pathElement)
+			}
+		}
+	}
+	return &Set{
+		Members:  members,
+		Children: *s.Children.EnsureNamedFieldsAreMembers(sc, tr),
+	}
+}
+
+// Size returns the number of members of the set.
+func (s *Set) Size() int {
+	return s.Members.Size() + s.Children.Size()
+}
+
+// Empty returns true if there are no members of the set. It is a separate
+// function from Size since it's common to check whether size > 0, and
+// potentially much faster to return as soon as a single element is found.
+func (s *Set) Empty() bool {
+	if s.Members.Size() > 0 {
+		return false
+	}
+	return s.Children.Empty()
+}
+
+// Has returns true if the field referenced by `p` is a member of the set.
+func (s *Set) Has(p Path) bool {
+	if len(p) == 0 {
+		// No one owns "the entire object"
+		return false
+	}
+	for {
+		if len(p) == 1 {
+			return s.Members.Has(p[0])
+		}
+		var ok bool
+		s, ok = s.Children.Get(p[0])
+		if !ok {
+			return false
+		}
+		p = p[1:]
+	}
+}
+
+// Equals returns true if s and s2 have exactly the same members.
+func (s *Set) Equals(s2 *Set) bool {
+	return s.Members.Equals(&s2.Members) && s.Children.Equals(&s2.Children)
+}
+
+// String returns the set one element per line.
+func (s *Set) String() string {
+	elements := []string{}
+	s.Iterate(func(p Path) {
+		elements = append(elements, p.String())
+	})
+	return strings.Join(elements, "\n")
+}
+
+// Iterate calls f once for each field that is a member of the set (preorder
+// DFS). The path passed to f will be reused so make a copy if you wish to keep
+// it.
+func (s *Set) Iterate(f func(Path)) {
+	s.iteratePrefix(Path{}, f)
+}
+
+func (s *Set) iteratePrefix(prefix Path, f func(Path)) {
+	s.Members.Iterate(func(pe PathElement) { f(append(prefix, pe)) })
+	s.Children.iteratePrefix(prefix, f)
+}
+
+// WithPrefix returns the subset of paths which begin with the given prefix,
+// with the prefix not included.
+func (s *Set) WithPrefix(pe PathElement) *Set {
+	subset, ok := s.Children.Get(pe)
+	if !ok {
+		return NewSet()
+	}
+	return subset
+}
+
+// Leaves returns a set containing only the leaf paths
+// of a set.
+func (s *Set) Leaves() *Set {
+	leaves := PathElementSet{}
+	im := 0
+	ic := 0
+
+	// any members that are not also children are leaves
+outer:
+	for im < len(s.Members.members) {
+		member := s.Members.members[im]
+
+		for ic < len(s.Children.members) {
+			d := member.Compare(s.Children.members[ic].pathElement)
+			if d == 0 {
+				ic++
+				im++
+				continue outer
+			} else if d < 0 {
+				break
+			} else /* if d > 0 */ {
+				ic++
+			}
+		}
+		leaves.members = append(leaves.members, member)
+		im++
+	}
+
+	return &Set{
+		Members:  leaves,
+		Children: *s.Children.Leaves(),
+	}
+}
+
+// setNode is a pair of PathElement / Set, for the purpose of expressing
+// nested set membership.
+type setNode struct {
+	pathElement PathElement
+	set         *Set
+}
+
+// SetNodeMap is a map of PathElement to subset.
+type SetNodeMap struct {
+	members sortedSetNode
+}
+
+type sortedSetNode []setNode
+
+// Implement the sort interface; this would permit bulk creation, which would
+// be faster than doing it one at a time via Insert.
+func (s sortedSetNode) Len() int           { return len(s) }
+func (s sortedSetNode) Less(i, j int) bool { return s[i].pathElement.Less(s[j].pathElement) }
+func (s sortedSetNode) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// Descend adds pe to the set if necessary, returning the associated subset.
+func (s *SetNodeMap) Descend(pe PathElement) *Set {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].pathElement.Less(pe)
+	})
+	if loc == len(s.members) {
+		s.members = append(s.members, setNode{pathElement: pe, set: &Set{}})
+		return s.members[loc].set
+	}
+	if s.members[loc].pathElement.Equals(pe) {
+		return s.members[loc].set
+	}
+	s.members = append(s.members, setNode{})
+	copy(s.members[loc+1:], s.members[loc:])
+	s.members[loc] = setNode{pathElement: pe, set: &Set{}}
+	return s.members[loc].set
+}
+
+// Size returns the sum of the number of members of all subsets.
+func (s *SetNodeMap) Size() int {
+	count := 0
+	for _, v := range s.members {
+		count += v.set.Size()
+	}
+	return count
+}
+
+// Empty returns false if there's at least one member in some child set.
+func (s *SetNodeMap) Empty() bool {
+	for _, n := range s.members {
+		if !n.set.Empty() {
+			return false
+		}
+	}
+	return true
+}
+
+// Get returns (the associated set, true) or (nil, false) if there is none.
+func (s *SetNodeMap) Get(pe PathElement) (*Set, bool) {
+	loc := sort.Search(len(s.members), func(i int) bool {
+		return !s.members[i].pathElement.Less(pe)
+	})
+	if loc == len(s.members) {
+		return nil, false
+	}
+	if s.members[loc].pathElement.Equals(pe) {
+		return s.members[loc].set, true
+	}
+	return nil, false
+}
+
+// Equals returns true if s and s2 have the same structure (same nested
+// child sets).
+func (s *SetNodeMap) Equals(s2 *SetNodeMap) bool {
+	if len(s.members) != len(s2.members) {
+		return false
+	}
+	for i := range s.members {
+		if !s.members[i].pathElement.Equals(s2.members[i].pathElement) {
+			return false
+		}
+		if !s.members[i].set.Equals(s2.members[i].set) {
+			return false
+		}
+	}
+	return true
+}
+
+// Union returns a SetNodeMap with members that appear in either s or s2.
+func (s *SetNodeMap) Union(s2 *SetNodeMap) *SetNodeMap {
+	out := &SetNodeMap{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.members) {
+		if s.members[i].pathElement.Less(s2.members[j].pathElement) {
+			out.members = append(out.members, s.members[i])
+			i++
+		} else {
+			if !s2.members[j].pathElement.Less(s.members[i].pathElement) {
+				out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: s.members[i].set.Union(s2.members[j].set)})
+				i++
+			} else {
+				out.members = append(out.members, s2.members[j])
+			}
+			j++
+		}
+	}
+
+	if i < len(s.members) {
+		out.members = append(out.members, s.members[i:]...)
+	}
+	if j < len(s2.members) {
+		out.members = append(out.members, s2.members[j:]...)
+	}
+	return out
+}
+
+// Intersection returns a SetNodeMap with members that appear in both s and s2.
+func (s *SetNodeMap) Intersection(s2 *SetNodeMap) *SetNodeMap {
+	out := &SetNodeMap{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.members) {
+		if s.members[i].pathElement.Less(s2.members[j].pathElement) {
+			i++
+		} else {
+			if !s2.members[j].pathElement.Less(s.members[i].pathElement) {
+				res := s.members[i].set.Intersection(s2.members[j].set)
+				if !res.Empty() {
+					out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: res})
+				}
+				i++
+			}
+			j++
+		}
+	}
+	return out
+}
+
+// Difference returns a SetNodeMap with members that appear in s but not in s2.
+func (s *SetNodeMap) Difference(s2 *Set) *SetNodeMap {
+	out := &SetNodeMap{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.Children.members) {
+		if s.members[i].pathElement.Less(s2.Children.members[j].pathElement) {
+			out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: s.members[i].set})
+			i++
+		} else {
+			if !s2.Children.members[j].pathElement.Less(s.members[i].pathElement) {
+
+				diff := s.members[i].set.Difference(s2.Children.members[j].set)
+				// We aren't permitted to add nodes with no elements.
+				if !diff.Empty() {
+					out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: diff})
+				}
+
+				i++
+			}
+			j++
+		}
+	}
+
+	if i < len(s.members) {
+		out.members = append(out.members, s.members[i:]...)
+	}
+	return out
+}
+
+// RecursiveDifference returns a SetNodeMap with members that appear in s but not in s2.
+//
+// Compared to a regular difference,
+// this removes every field **and its children** from s that is contained in s2.
+//
+// For example, with s containing `a.b.c` and s2 containing `a.b`,
+// a RecursiveDifference will result in `a`, as the entire node `a.b` gets removed.
+func (s *SetNodeMap) RecursiveDifference(s2 *Set) *SetNodeMap {
+	out := &SetNodeMap{}
+
+	i, j := 0, 0
+	for i < len(s.members) && j < len(s2.Children.members) {
+		if s.members[i].pathElement.Less(s2.Children.members[j].pathElement) {
+			if !s2.Members.Has(s.members[i].pathElement) {
+				out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: s.members[i].set})
+			}
+			i++
+		} else {
+			if !s2.Children.members[j].pathElement.Less(s.members[i].pathElement) {
+				if !s2.Members.Has(s.members[i].pathElement) {
+					diff := s.members[i].set.RecursiveDifference(s2.Children.members[j].set)
+					if !diff.Empty() {
+						out.members = append(out.members, setNode{pathElement: s.members[i].pathElement, set: diff})
+					}
+				}
+				i++
+			}
+			j++
+		}
+	}
+
+	if i < len(s.members) {
+		for _, c := range s.members[i:] {
+			if !s2.Members.Has(c.pathElement) {
+				out.members = append(out.members, c)
+			}
+		}
+	}
+
+	return out
+}
+
+// EnsureNamedFieldsAreMembers returns a set that contains all the named fields along with the leaves.
+func (s *SetNodeMap) EnsureNamedFieldsAreMembers(sc *schema.Schema, tr schema.TypeRef) *SetNodeMap {
+	out := make(sortedSetNode, 0, s.Size())
+	atom, _ := sc.Resolve(tr)
+	for _, member := range s.members {
+		tr := schema.TypeRef{}
+		if member.pathElement.FieldName != nil && atom.Map != nil {
+			tr = atom.Map.ElementType
+			if sf, ok := atom.Map.FindField(*member.pathElement.FieldName); ok {
+				tr = sf.Type
+			}
+		} else if member.pathElement.Key != nil && atom.List != nil {
+			tr = atom.List.ElementType
+		}
+		out = append(out, setNode{
+			pathElement: member.pathElement,
+			set:         member.set.EnsureNamedFieldsAreMembers(sc, tr),
+		})
+	}
+
+	return &SetNodeMap{
+		members: out,
+	}
+}
+
+// Iterate calls f for each PathElement in the set.
+func (s *SetNodeMap) Iterate(f func(PathElement)) {
+	for _, n := range s.members {
+		f(n.pathElement)
+	}
+}
+
+func (s *SetNodeMap) iteratePrefix(prefix Path, f func(Path)) {
+	for _, n := range s.members {
+		pe := n.pathElement
+		n.set.iteratePrefix(append(prefix, pe), f)
+	}
+}
+
+// Leaves returns a SetNodeMap containing
+// only setNodes with leaf PathElements.
+func (s *SetNodeMap) Leaves() *SetNodeMap {
+	out := &SetNodeMap{}
+	out.members = make(sortedSetNode, len(s.members))
+	for i, n := range s.members {
+		out.members[i] = setNode{
+			pathElement: n.pathElement,
+			set:         n.set.Leaves(),
+		}
+	}
+	return out
+}