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/apiserver-network-proxy/konnectivity-client/pkg/client/client.go

@@ -19,6 +19,7 @@ package client
 import (
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"math/rand"
 	"net"
@@ -49,6 +50,10 @@ type grpcTunnel struct {
 	conns           map[int64]*conn
 	pendingDialLock sync.RWMutex
 	connsLock       sync.RWMutex
+
+	// The tunnel will be closed if the caller fails to read via conn.Read()
+	// more than readTimeoutSeconds after a packet has been received.
+	readTimeoutSeconds int
 }
 
 type clientConn interface {
@@ -75,9 +80,10 @@ func CreateSingleUseGrpcTunnel(address string, opts ...grpc.DialOption) (Tunnel,
 	}
 
 	tunnel := &grpcTunnel{
-		stream:      stream,
-		pendingDial: make(map[int64]chan<- dialResult),
-		conns:       make(map[int64]*conn),
+		stream:             stream,
+		pendingDial:        make(map[int64]chan<- dialResult),
+		conns:              make(map[int64]*conn),
+		readTimeoutSeconds: 10,
 	}
 
 	go tunnel.serve(c)
@@ -110,10 +116,17 @@ func (t *grpcTunnel) serve(c clientConn) {
 			if !ok {
 				klog.V(1).Infoln("DialResp not recognized; dropped")
 			} else {
-				ch <- dialResult{
+				result := dialResult{
 					err:    resp.Error,
 					connid: resp.ConnectID,
 				}
+				select  {
+				case ch <- result:
+				default:
+					klog.ErrorS(fmt.Errorf("blocked pending channel"), "Received second dial response for connection request", "connectionID", resp.ConnectID, "dialID", resp.Random)
+					// On multiple dial responses, avoid leaking serve goroutine.
+					return
+				}
 			}
 
 			if resp.Error != "" {
@@ -129,7 +142,14 @@ func (t *grpcTunnel) serve(c clientConn) {
 			t.connsLock.RUnlock()
 
 			if ok {
-				conn.readCh <- resp.Data
+				timer := time.NewTimer((time.Duration)(t.readTimeoutSeconds) * time.Second)
+				select {
+				case conn.readCh <- resp.Data:
+					timer.Stop()
+				case <-timer.C:
+					klog.ErrorS(fmt.Errorf("timeout"), "readTimeout has been reached, the grpc connection to the proxy server will be closed", "connectionID", conn.connID, "readTimeoutSeconds", t.readTimeoutSeconds)
+					return
+				}
 			} else {
 				klog.V(1).InfoS("connection not recognized", "connectionID", resp.ConnectID)
 			}
@@ -160,8 +180,8 @@ func (t *grpcTunnel) Dial(protocol, address string) (net.Conn, error) {
 		return nil, errors.New("protocol not supported")
 	}
 
-	random := rand.Int63()
-	resCh := make(chan dialResult)
+	random := rand.Int63() /* #nosec G404 */
+	resCh := make(chan dialResult, 1)
 	t.pendingDialLock.Lock()
 	t.pendingDial[random] = resCh
 	t.pendingDialLock.Unlock()
@@ -199,7 +219,7 @@ func (t *grpcTunnel) Dial(protocol, address string) (net.Conn, error) {
 		}
 		c.connID = res.connid
 		c.readCh = make(chan []byte, 10)
-		c.closeCh = make(chan string)
+		c.closeCh = make(chan string, 1)
 		t.connsLock.Lock()
 		t.conns[res.connid] = c
 		t.connsLock.Unlock()

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
+}

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

@@ -0,0 +1,28 @@
+/*
+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 schema defines a targeted schema language which allows one to
+// represent all the schema information necessary to perform "structured"
+// merges and diffs.
+//
+// Due to the targeted nature of the data model, the schema language can fit in
+// just a few hundred lines of go code, making it much more understandable and
+// concise than e.g. OpenAPI.
+//
+// This schema was derived by observing the API objects used by Kubernetes, and
+// formalizing a model which allows certain operations ("apply") to be more
+// well defined. It is currently missing one feature: one-of ("unions").
+package schema

vendor/sigs.k8s.io/structured-merge-diff/v4/schema/elements.go

@@ -0,0 +1,261 @@
+/*
+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 schema
+
+import "sync"
+
+// Schema is a list of named types.
+//
+// Schema types are indexed in a map before the first search so this type
+// should be considered immutable.
+type Schema struct {
+	Types []TypeDef `yaml:"types,omitempty"`
+
+	once sync.Once
+	m    map[string]TypeDef
+}
+
+// A TypeSpecifier references a particular type in a schema.
+type TypeSpecifier struct {
+	Type   TypeRef `yaml:"type,omitempty"`
+	Schema Schema  `yaml:"schema,omitempty"`
+}
+
+// TypeDef represents a named type in a schema.
+type TypeDef struct {
+	// Top level types should be named. Every type must have a unique name.
+	Name string `yaml:"name,omitempty"`
+
+	Atom `yaml:"atom,omitempty,inline"`
+}
+
+// TypeRef either refers to a named type or declares an inlined type.
+type TypeRef struct {
+	// Either the name or one member of Atom should be set.
+	NamedType *string `yaml:"namedType,omitempty"`
+	Inlined   Atom    `yaml:",inline,omitempty"`
+}
+
+// Atom represents the smallest possible pieces of the type system.
+// Each set field in the Atom represents a possible type for the object.
+// If none of the fields are set, any object will fail validation against the atom.
+type Atom struct {
+	*Scalar `yaml:"scalar,omitempty"`
+	*List   `yaml:"list,omitempty"`
+	*Map    `yaml:"map,omitempty"`
+}
+
+// Scalar (AKA "primitive") represents a type which has a single value which is
+// either numeric, string, or boolean.
+//
+// TODO: split numeric into float/int? Something even more fine-grained?
+type Scalar string
+
+const (
+	Numeric = Scalar("numeric")
+	String  = Scalar("string")
+	Boolean = Scalar("boolean")
+)
+
+// ElementRelationship is an enum of the different possible relationships
+// between the elements of container types (maps, lists).
+type ElementRelationship string
+
+const (
+	// Associative only applies to lists (see the documentation there).
+	Associative = ElementRelationship("associative")
+	// Atomic makes container types (lists, maps) behave
+	// as scalars / leaf fields
+	Atomic = ElementRelationship("atomic")
+	// Separable means the items of the container type have no particular
+	// relationship (default behavior for maps).
+	Separable = ElementRelationship("separable")
+)
+
+// Map is a key-value pair. Its default semantics are the same as an
+// associative list, but:
+// * It is serialized differently:
+//     map:  {"k": {"value": "v"}}
+//     list: [{"key": "k", "value": "v"}]
+// * Keys must be string typed.
+// * Keys can't have multiple components.
+//
+// Optionally, maps may be atomic (for example, imagine representing an RGB
+// color value--it doesn't make sense to have different actors own the R and G
+// values).
+//
+// Maps may also represent a type which is composed of a number of different fields.
+// Each field has a name and a type.
+//
+// Fields are indexed in a map before the first search so this type
+// should be considered immutable.
+type Map struct {
+	// Each struct field appears exactly once in this list. The order in
+	// this list defines the canonical field ordering.
+	Fields []StructField `yaml:"fields,omitempty"`
+
+	// A Union is a grouping of fields with special rules. It may refer to
+	// one or more fields in the above list. A given field from the above
+	// list may be referenced in exactly 0 or 1 places in the below list.
+	// One can have multiple unions in the same struct, but the fields can't
+	// overlap between unions.
+	Unions []Union `yaml:"unions,omitempty"`
+
+	// ElementType is the type of the structs's unknown fields.
+	ElementType TypeRef `yaml:"elementType,omitempty"`
+
+	// ElementRelationship states the relationship between the map's items.
+	// * `separable` (or unset) implies that each element is 100% independent.
+	// * `atomic` implies that all elements depend on each other, and this
+	//   is effectively a scalar / leaf field; it doesn't make sense for
+	//   separate actors to set the elements. Example: an RGB color struct;
+	//   it would never make sense to "own" only one component of the
+	//   color.
+	// The default behavior for maps is `separable`; it's permitted to
+	// leave this unset to get the default behavior.
+	ElementRelationship ElementRelationship `yaml:"elementRelationship,omitempty"`
+
+	once sync.Once
+	m    map[string]StructField
+}
+
+// FindField is a convenience function that returns the referenced StructField,
+// if it exists, or (nil, false) if it doesn't.
+func (m *Map) FindField(name string) (StructField, bool) {
+	m.once.Do(func() {
+		m.m = make(map[string]StructField, len(m.Fields))
+		for _, field := range m.Fields {
+			m.m[field.Name] = field
+		}
+	})
+	sf, ok := m.m[name]
+	return sf, ok
+}
+
+// UnionFields are mapping between the fields that are part of the union and
+// their discriminated value. The discriminated value has to be set, and
+// should not conflict with other discriminated value in the list.
+type UnionField struct {
+	// FieldName is the name of the field that is part of the union. This
+	// is the serialized form of the field.
+	FieldName string `yaml:"fieldName"`
+	// Discriminatorvalue is the value of the discriminator to
+	// select that field. If the union doesn't have a discriminator,
+	// this field is ignored.
+	DiscriminatorValue string `yaml:"discriminatorValue"`
+}
+
+// Union, or oneof, means that only one of multiple fields of a structure can be
+// set at a time. Setting the discriminator helps clearing oher fields:
+// - If discriminator changed to non-nil, and a new field has been added
+// that doesn't match, an error is returned,
+// - If discriminator hasn't changed and two fields or more are set, an
+// error is returned,
+// - If discriminator changed to non-nil, all other fields but the
+// discriminated one will be cleared,
+// - Otherwise, If only one field is left, update discriminator to that value.
+type Union struct {
+	// Discriminator, if present, is the name of the field that
+	// discriminates fields in the union. The mapping between the value of
+	// the discriminator and the field is done by using the Fields list
+	// below.
+	Discriminator *string `yaml:"discriminator,omitempty"`
+
+	// DeduceInvalidDiscriminator indicates if the discriminator
+	// should be updated automatically based on the fields set. This
+	// typically defaults to false since we don't want to deduce by
+	// default (the behavior exists to maintain compatibility on
+	// existing types and shouldn't be used for new types).
+	DeduceInvalidDiscriminator bool `yaml:"deduceInvalidDiscriminator,omitempty"`
+
+	// This is the list of fields that belong to this union. All the
+	// fields present in here have to be part of the parent
+	// structure. Discriminator (if oneOf has one), is NOT included in
+	// this list. The value for field is how we map the name of the field
+	// to actual value for discriminator.
+	Fields []UnionField `yaml:"fields,omitempty"`
+}
+
+// StructField pairs a field name with a field type.
+type StructField struct {
+	// Name is the field name.
+	Name string `yaml:"name,omitempty"`
+	// Type is the field type.
+	Type TypeRef `yaml:"type,omitempty"`
+	// Default value for the field, nil if not present.
+	Default interface{} `yaml:"default,omitempty"`
+}
+
+// List represents a type which contains a zero or more elements, all of the
+// same subtype. Lists may be either associative: each element is more or less
+// independent and could be managed by separate entities in the system; or
+// atomic, where the elements are heavily dependent on each other: it is not
+// sensible to change one element without considering the ramifications on all
+// the other elements.
+type List struct {
+	// ElementType is the type of the list's elements.
+	ElementType TypeRef `yaml:"elementType,omitempty"`
+
+	// ElementRelationship states the relationship between the list's elements
+	// and must have one of these values:
+	// * `atomic`: the list is treated as a single entity, like a scalar.
+	// * `associative`:
+	//   - If the list element is a scalar, the list is treated as a set.
+	//   - If the list element is a map, the list is treated as a map.
+	// There is no default for this value for lists; all schemas must
+	// explicitly state the element relationship for all lists.
+	ElementRelationship ElementRelationship `yaml:"elementRelationship,omitempty"`
+
+	// Iff ElementRelationship is `associative`, and the element type is
+	// map, then Keys must have non-zero length, and it lists the fields
+	// of the element's map type which are to be used as the keys of the
+	// list.
+	//
+	// TODO: change this to "non-atomic struct" above and make the code reflect this.
+	//
+	// Each key must refer to a single field name (no nesting, not JSONPath).
+	Keys []string `yaml:"keys,omitempty"`
+}
+
+// FindNamedType is a convenience function that returns the referenced TypeDef,
+// if it exists, or (nil, false) if it doesn't.
+func (s *Schema) FindNamedType(name string) (TypeDef, bool) {
+	s.once.Do(func() {
+		s.m = make(map[string]TypeDef, len(s.Types))
+		for _, t := range s.Types {
+			s.m[t.Name] = t
+		}
+	})
+	t, ok := s.m[name]
+	return t, ok
+}
+
+// Resolve is a convenience function which returns the atom referenced, whether
+// it is inline or named. Returns (Atom{}, false) if the type can't be resolved.
+//
+// This allows callers to not care about the difference between a (possibly
+// inlined) reference and a definition.
+func (s *Schema) Resolve(tr TypeRef) (Atom, bool) {
+	if tr.NamedType != nil {
+		t, ok := s.FindNamedType(*tr.NamedType)
+		if !ok {
+			return Atom{}, false
+		}
+		return t.Atom, true
+	}
+	return tr.Inlined, true
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/schema/equals.go

@@ -0,0 +1,199 @@
+/*
+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 schema
+
+import "reflect"
+
+// Equals returns true iff the two Schemas are equal.
+func (a *Schema) Equals(b *Schema) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+
+	if len(a.Types) != len(b.Types) {
+		return false
+	}
+	for i := range a.Types {
+		if !a.Types[i].Equals(&b.Types[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Equals returns true iff the two TypeRefs are equal.
+//
+// Note that two typerefs that have an equivalent type but where one is
+// inlined and the other is named, are not considered equal.
+func (a *TypeRef) Equals(b *TypeRef) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if (a.NamedType == nil) != (b.NamedType == nil) {
+		return false
+	}
+	if a.NamedType != nil {
+		if *a.NamedType != *b.NamedType {
+			return false
+		}
+		//return true
+	}
+	return a.Inlined.Equals(&b.Inlined)
+}
+
+// Equals returns true iff the two TypeDefs are equal.
+func (a *TypeDef) Equals(b *TypeDef) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if a.Name != b.Name {
+		return false
+	}
+	return a.Atom.Equals(&b.Atom)
+}
+
+// Equals returns true iff the two Atoms are equal.
+func (a *Atom) Equals(b *Atom) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if (a.Scalar == nil) != (b.Scalar == nil) {
+		return false
+	}
+	if (a.List == nil) != (b.List == nil) {
+		return false
+	}
+	if (a.Map == nil) != (b.Map == nil) {
+		return false
+	}
+	switch {
+	case a.Scalar != nil:
+		return *a.Scalar == *b.Scalar
+	case a.List != nil:
+		return a.List.Equals(b.List)
+	case a.Map != nil:
+		return a.Map.Equals(b.Map)
+	}
+	return true
+}
+
+// Equals returns true iff the two Maps are equal.
+func (a *Map) Equals(b *Map) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if !a.ElementType.Equals(&b.ElementType) {
+		return false
+	}
+	if a.ElementRelationship != b.ElementRelationship {
+		return false
+	}
+	if len(a.Fields) != len(b.Fields) {
+		return false
+	}
+	for i := range a.Fields {
+		if !a.Fields[i].Equals(&b.Fields[i]) {
+			return false
+		}
+	}
+	if len(a.Unions) != len(b.Unions) {
+		return false
+	}
+	for i := range a.Unions {
+		if !a.Unions[i].Equals(&b.Unions[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Equals returns true iff the two Unions are equal.
+func (a *Union) Equals(b *Union) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if (a.Discriminator == nil) != (b.Discriminator == nil) {
+		return false
+	}
+	if a.Discriminator != nil {
+		if *a.Discriminator != *b.Discriminator {
+			return false
+		}
+	}
+	if a.DeduceInvalidDiscriminator != b.DeduceInvalidDiscriminator {
+		return false
+	}
+	if len(a.Fields) != len(b.Fields) {
+		return false
+	}
+	for i := range a.Fields {
+		if !a.Fields[i].Equals(&b.Fields[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Equals returns true iff the two UnionFields are equal.
+func (a *UnionField) Equals(b *UnionField) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if a.FieldName != b.FieldName {
+		return false
+	}
+	if a.DiscriminatorValue != b.DiscriminatorValue {
+		return false
+	}
+	return true
+}
+
+// Equals returns true iff the two StructFields are equal.
+func (a *StructField) Equals(b *StructField) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if a.Name != b.Name {
+		return false
+	}
+	if !reflect.DeepEqual(a.Default, b.Default) {
+		return false
+	}
+	return a.Type.Equals(&b.Type)
+}
+
+// Equals returns true iff the two Lists are equal.
+func (a *List) Equals(b *List) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	if !a.ElementType.Equals(&b.ElementType) {
+		return false
+	}
+	if a.ElementRelationship != b.ElementRelationship {
+		return false
+	}
+	if len(a.Keys) != len(b.Keys) {
+		return false
+	}
+	for i := range a.Keys {
+		if a.Keys[i] != b.Keys[i] {
+			return false
+		}
+	}
+	return true
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/schema/schemaschema.go

@@ -0,0 +1,161 @@
+/*
+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 schema
+
+// SchemaSchemaYAML is a schema against which you can validate other schemas.
+// It will validate itself. It can be unmarshalled into a Schema type.
+var SchemaSchemaYAML = `types:
+- name: schema
+  map:
+    fields:
+      - name: types
+        type:
+          list:
+            elementRelationship: associative
+            elementType:
+              namedType: typeDef
+            keys:
+            - name
+- name: typeDef
+  map:
+    fields:
+    - name: name
+      type:
+        scalar: string
+    - name: scalar
+      type:
+        scalar: string
+    - name: map
+      type:
+        namedType: map
+    - name: list
+      type:
+        namedType: list
+    - name: untyped
+      type:
+        namedType: untyped
+- name: typeRef
+  map:
+    fields:
+    - name: namedType
+      type:
+        scalar: string
+    - name: scalar
+      type:
+        scalar: string
+    - name: map
+      type:
+        namedType: map
+    - name: list
+      type:
+        namedType: list
+    - name: untyped
+      type:
+        namedType: untyped
+- name: scalar
+  scalar: string
+- name: map
+  map:
+    fields:
+    - name: fields
+      type:
+        list:
+          elementType:
+            namedType: structField
+          elementRelationship: associative
+          keys: [ "name" ]
+    - name: unions
+      type:
+        list:
+          elementType:
+            namedType: union
+          elementRelationship: atomic
+    - name: elementType
+      type:
+        namedType: typeRef
+    - name: elementRelationship
+      type:
+        scalar: string
+- name: unionField
+  map:
+    fields:
+    - name: fieldName
+      type:
+        scalar: string
+    - name: discriminatorValue
+      type:
+        scalar: string
+- name: union
+  map:
+    fields:
+    - name: discriminator
+      type:
+        scalar: string
+    - name: deduceInvalidDiscriminator
+      type:
+        scalar: bool
+    - name: fields
+      type:
+        list:
+          elementRelationship: associative
+          elementType:
+            namedType: unionField
+          keys:
+          - fieldName
+- name: structField
+  map:
+    fields:
+    - name: name
+      type:
+        scalar: string
+    - name: type
+      type:
+        namedType: typeRef
+    - name: default
+      type:
+        namedType: __untyped_atomic_
+- name: list
+  map:
+    fields:
+    - name: elementType
+      type:
+        namedType: typeRef
+    - name: elementRelationship
+      type:
+        scalar: string
+    - name: keys
+      type:
+        list:
+          elementType:
+            scalar: string
+- name: untyped
+  map:
+    fields:
+    - name: elementRelationship
+      type:
+        scalar: string
+- name: __untyped_atomic_
+  scalar: untyped
+  list:
+    elementType:
+      namedType: __untyped_atomic_
+    elementRelationship: atomic
+  map:
+    elementType:
+      namedType: __untyped_atomic_
+    elementRelationship: atomic
+`

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

@@ -0,0 +1,18 @@
+/*
+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 typed contains logic for operating on values with given schemas.
+package typed

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/helpers.go

@@ -0,0 +1,256 @@
+/*
+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 typed
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// ValidationError reports an error about a particular field
+type ValidationError struct {
+	Path         string
+	ErrorMessage string
+}
+
+// Error returns a human readable error message.
+func (ve ValidationError) Error() string {
+	if len(ve.Path) == 0 {
+		return ve.ErrorMessage
+	}
+	return fmt.Sprintf("%s: %v", ve.Path, ve.ErrorMessage)
+}
+
+// ValidationErrors accumulates multiple validation error messages.
+type ValidationErrors []ValidationError
+
+// Error returns a human readable error message reporting each error in the
+// list.
+func (errs ValidationErrors) Error() string {
+	if len(errs) == 1 {
+		return errs[0].Error()
+	}
+	messages := []string{"errors:"}
+	for _, e := range errs {
+		messages = append(messages, "  "+e.Error())
+	}
+	return strings.Join(messages, "\n")
+}
+
+// Set the given path to all the validation errors.
+func (errs ValidationErrors) WithPath(p string) ValidationErrors {
+	for i := range errs {
+		errs[i].Path = p
+	}
+	return errs
+}
+
+// WithPrefix prefixes all errors path with the given pathelement. This
+// is useful when unwinding the stack on errors.
+func (errs ValidationErrors) WithPrefix(prefix string) ValidationErrors {
+	for i := range errs {
+		errs[i].Path = prefix + errs[i].Path
+	}
+	return errs
+}
+
+// WithLazyPrefix prefixes all errors path with the given pathelement.
+// This is useful when unwinding the stack on errors. Prefix is
+// computed lazily only if there is an error.
+func (errs ValidationErrors) WithLazyPrefix(fn func() string) ValidationErrors {
+	if len(errs) == 0 {
+		return errs
+	}
+	prefix := ""
+	if fn != nil {
+		prefix = fn()
+	}
+	for i := range errs {
+		errs[i].Path = prefix + errs[i].Path
+	}
+	return errs
+}
+
+func errorf(format string, args ...interface{}) ValidationErrors {
+	return ValidationErrors{{
+		ErrorMessage: fmt.Sprintf(format, args...),
+	}}
+}
+
+type atomHandler interface {
+	doScalar(*schema.Scalar) ValidationErrors
+	doList(*schema.List) ValidationErrors
+	doMap(*schema.Map) ValidationErrors
+}
+
+func resolveSchema(s *schema.Schema, tr schema.TypeRef, v value.Value, ah atomHandler) ValidationErrors {
+	a, ok := s.Resolve(tr)
+	if !ok {
+		return errorf("schema error: no type found matching: %v", *tr.NamedType)
+	}
+
+	a = deduceAtom(a, v)
+	return handleAtom(a, tr, ah)
+}
+
+// deduceAtom determines which of the possible types in atom 'atom' applies to value 'val'.
+// If val is of a type allowed by atom, return a copy of atom with all other types set to nil.
+// if val is nil, or is not of a type allowed by atom, just return the original atom,
+// and validation will fail at a later stage. (with a more useful error)
+func deduceAtom(atom schema.Atom, val value.Value) schema.Atom {
+	switch {
+	case val == nil:
+	case val.IsFloat(), val.IsInt(), val.IsString(), val.IsBool():
+		if atom.Scalar != nil {
+			return schema.Atom{Scalar: atom.Scalar}
+		}
+	case val.IsList():
+		if atom.List != nil {
+			return schema.Atom{List: atom.List}
+		}
+	case val.IsMap():
+		if atom.Map != nil {
+			return schema.Atom{Map: atom.Map}
+		}
+	}
+	return atom
+}
+
+func handleAtom(a schema.Atom, tr schema.TypeRef, ah atomHandler) ValidationErrors {
+	switch {
+	case a.Map != nil:
+		return ah.doMap(a.Map)
+	case a.Scalar != nil:
+		return ah.doScalar(a.Scalar)
+	case a.List != nil:
+		return ah.doList(a.List)
+	}
+
+	name := "inlined"
+	if tr.NamedType != nil {
+		name = "named type: " + *tr.NamedType
+	}
+
+	return errorf("schema error: invalid atom: %v", name)
+}
+
+// Returns the list, or an error. Reminder: nil is a valid list and might be returned.
+func listValue(a value.Allocator, val value.Value) (value.List, error) {
+	if val.IsNull() {
+		// Null is a valid list.
+		return nil, nil
+	}
+	if !val.IsList() {
+		return nil, fmt.Errorf("expected list, got %v", val)
+	}
+	return val.AsListUsing(a), nil
+}
+
+// Returns the map, or an error. Reminder: nil is a valid map and might be returned.
+func mapValue(a value.Allocator, val value.Value) (value.Map, error) {
+	if val == nil {
+		return nil, fmt.Errorf("expected map, got nil")
+	}
+	if val.IsNull() {
+		// Null is a valid map.
+		return nil, nil
+	}
+	if !val.IsMap() {
+		return nil, fmt.Errorf("expected map, got %v", val)
+	}
+	return val.AsMapUsing(a), nil
+}
+
+func getAssociativeKeyDefault(s *schema.Schema, list *schema.List, fieldName string) (interface{}, error) {
+	atom, ok := s.Resolve(list.ElementType)
+	if !ok {
+		return nil, errors.New("invalid elementType for list")
+	}
+	if atom.Map == nil {
+		return nil, errors.New("associative list may not have non-map types")
+	}
+	// If the field is not found, we can assume there is no default.
+	field, _ := atom.Map.FindField(fieldName)
+	return field.Default, nil
+}
+
+func keyedAssociativeListItemToPathElement(a value.Allocator, s *schema.Schema, list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
+	pe := fieldpath.PathElement{}
+	if child.IsNull() {
+		// null entries are illegal.
+		return pe, errors.New("associative list with keys may not have a null element")
+	}
+	if !child.IsMap() {
+		return pe, errors.New("associative list with keys may not have non-map elements")
+	}
+	keyMap := value.FieldList{}
+	m := child.AsMapUsing(a)
+	defer a.Free(m)
+	for _, fieldName := range list.Keys {
+		if val, ok := m.Get(fieldName); ok {
+			keyMap = append(keyMap, value.Field{Name: fieldName, Value: val})
+		} else if def, err := getAssociativeKeyDefault(s, list, fieldName); err != nil {
+			return pe, fmt.Errorf("couldn't find default value for %v: %v", fieldName, err)
+		} else if def != nil {
+			keyMap = append(keyMap, value.Field{Name: fieldName, Value: value.NewValueInterface(def)})
+		} else {
+			return pe, fmt.Errorf("associative list with keys has an element that omits key field %q (and doesn't have default value)", fieldName)
+		}
+	}
+	keyMap.Sort()
+	pe.Key = &keyMap
+	return pe, nil
+}
+
+func setItemToPathElement(list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
+	pe := fieldpath.PathElement{}
+	switch {
+	case child.IsMap():
+		// TODO: atomic maps should be acceptable.
+		return pe, errors.New("associative list without keys has an element that's a map type")
+	case child.IsList():
+		// Should we support a set of lists? For the moment
+		// let's say we don't.
+		// TODO: atomic lists should be acceptable.
+		return pe, errors.New("not supported: associative list with lists as elements")
+	case child.IsNull():
+		return pe, errors.New("associative list without keys has an element that's an explicit null")
+	default:
+		// We are a set type.
+		pe.Value = &child
+		return pe, nil
+	}
+}
+
+func listItemToPathElement(a value.Allocator, s *schema.Schema, list *schema.List, index int, child value.Value) (fieldpath.PathElement, error) {
+	if list.ElementRelationship == schema.Associative {
+		if len(list.Keys) > 0 {
+			return keyedAssociativeListItemToPathElement(a, s, list, index, child)
+		}
+
+		// If there's no keys, then we must be a set of primitives.
+		return setItemToPathElement(list, index, child)
+	}
+
+	// Use the index as a key for atomic lists.
+	return fieldpath.PathElement{Index: &index}, nil
+}

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

@@ -0,0 +1,353 @@
+/*
+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 typed
+
+import (
+	"math"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+type mergingWalker struct {
+	lhs     value.Value
+	rhs     value.Value
+	schema  *schema.Schema
+	typeRef schema.TypeRef
+
+	// Current path that we are merging
+	path fieldpath.Path
+
+	// How to merge. Called after schema validation for all leaf fields.
+	rule mergeRule
+
+	// If set, called after non-leaf items have been merged. (`out` is
+	// probably already set.)
+	postItemHook mergeRule
+
+	// output of the merge operation (nil if none)
+	out *interface{}
+
+	// internal housekeeping--don't set when constructing.
+	inLeaf bool // Set to true if we're in a "big leaf"--atomic map/list
+
+	// Allocate only as many walkers as needed for the depth by storing them here.
+	spareWalkers *[]*mergingWalker
+
+	allocator value.Allocator
+}
+
+// merge rules examine w.lhs and w.rhs (up to one of which may be nil) and
+// optionally set w.out. If lhs and rhs are both set, they will be of
+// comparable type.
+type mergeRule func(w *mergingWalker)
+
+var (
+	ruleKeepRHS = mergeRule(func(w *mergingWalker) {
+		if w.rhs != nil {
+			v := w.rhs.Unstructured()
+			w.out = &v
+		} else if w.lhs != nil {
+			v := w.lhs.Unstructured()
+			w.out = &v
+		}
+	})
+)
+
+// merge sets w.out.
+func (w *mergingWalker) merge(prefixFn func() string) (errs ValidationErrors) {
+	if w.lhs == nil && w.rhs == nil {
+		// check this condidition here instead of everywhere below.
+		return errorf("at least one of lhs and rhs must be provided")
+	}
+	a, ok := w.schema.Resolve(w.typeRef)
+	if !ok {
+		return errorf("schema error: no type found matching: %v", *w.typeRef.NamedType)
+	}
+
+	alhs := deduceAtom(a, w.lhs)
+	arhs := deduceAtom(a, w.rhs)
+	if alhs.Equals(&arhs) {
+		errs = append(errs, handleAtom(arhs, w.typeRef, w)...)
+	} else {
+		w2 := *w
+		errs = append(errs, handleAtom(alhs, w.typeRef, &w2)...)
+		errs = append(errs, handleAtom(arhs, w.typeRef, w)...)
+	}
+
+	if !w.inLeaf && w.postItemHook != nil {
+		w.postItemHook(w)
+	}
+	return errs.WithLazyPrefix(prefixFn)
+}
+
+// doLeaf should be called on leaves before descending into children, if there
+// will be a descent. It modifies w.inLeaf.
+func (w *mergingWalker) doLeaf() {
+	if w.inLeaf {
+		// We're in a "big leaf", an atomic map or list. Ignore
+		// subsequent leaves.
+		return
+	}
+	w.inLeaf = true
+
+	// We don't recurse into leaf fields for merging.
+	w.rule(w)
+}
+
+func (w *mergingWalker) doScalar(t *schema.Scalar) (errs ValidationErrors) {
+	errs = append(errs, validateScalar(t, w.lhs, "lhs: ")...)
+	errs = append(errs, validateScalar(t, w.rhs, "rhs: ")...)
+	if len(errs) > 0 {
+		return errs
+	}
+
+	// All scalars are leaf fields.
+	w.doLeaf()
+
+	return nil
+}
+
+func (w *mergingWalker) prepareDescent(pe fieldpath.PathElement, tr schema.TypeRef) *mergingWalker {
+	if w.spareWalkers == nil {
+		// first descent.
+		w.spareWalkers = &[]*mergingWalker{}
+	}
+	var w2 *mergingWalker
+	if n := len(*w.spareWalkers); n > 0 {
+		w2, *w.spareWalkers = (*w.spareWalkers)[n-1], (*w.spareWalkers)[:n-1]
+	} else {
+		w2 = &mergingWalker{}
+	}
+	*w2 = *w
+	w2.typeRef = tr
+	w2.path = append(w2.path, pe)
+	w2.lhs = nil
+	w2.rhs = nil
+	w2.out = nil
+	return w2
+}
+
+func (w *mergingWalker) finishDescent(w2 *mergingWalker) {
+	// if the descent caused a realloc, ensure that we reuse the buffer
+	// for the next sibling.
+	w.path = w2.path[:len(w2.path)-1]
+	*w.spareWalkers = append(*w.spareWalkers, w2)
+}
+
+func (w *mergingWalker) derefMap(prefix string, v value.Value) (value.Map, ValidationErrors) {
+	if v == nil {
+		return nil, nil
+	}
+	m, err := mapValue(w.allocator, v)
+	if err != nil {
+		return nil, errorf("%v: %v", prefix, err)
+	}
+	return m, nil
+}
+
+func (w *mergingWalker) visitListItems(t *schema.List, lhs, rhs value.List) (errs ValidationErrors) {
+	rLen := 0
+	if rhs != nil {
+		rLen = rhs.Length()
+	}
+	lLen := 0
+	if lhs != nil {
+		lLen = lhs.Length()
+	}
+	out := make([]interface{}, 0, int(math.Max(float64(rLen), float64(lLen))))
+
+	// TODO: ordering is totally wrong.
+	// TODO: might as well make the map order work the same way.
+
+	// This is a cheap hack to at least make the output order stable.
+	rhsOrder := make([]fieldpath.PathElement, 0, rLen)
+
+	// First, collect all RHS children.
+	observedRHS := fieldpath.MakePathElementValueMap(rLen)
+	if rhs != nil {
+		for i := 0; i < rhs.Length(); i++ {
+			child := rhs.At(i)
+			pe, err := listItemToPathElement(w.allocator, w.schema, t, i, child)
+			if err != nil {
+				errs = append(errs, errorf("rhs: element %v: %v", i, err.Error())...)
+				// If we can't construct the path element, we can't
+				// even report errors deeper in the schema, so bail on
+				// this element.
+				continue
+			}
+			if _, ok := observedRHS.Get(pe); ok {
+				errs = append(errs, errorf("rhs: duplicate entries for key %v", pe.String())...)
+			}
+			observedRHS.Insert(pe, child)
+			rhsOrder = append(rhsOrder, pe)
+		}
+	}
+
+	// Then merge with LHS children.
+	observedLHS := fieldpath.MakePathElementSet(lLen)
+	if lhs != nil {
+		for i := 0; i < lhs.Length(); i++ {
+			child := lhs.At(i)
+			pe, err := listItemToPathElement(w.allocator, w.schema, t, i, child)
+			if err != nil {
+				errs = append(errs, errorf("lhs: element %v: %v", i, err.Error())...)
+				// If we can't construct the path element, we can't
+				// even report errors deeper in the schema, so bail on
+				// this element.
+				continue
+			}
+			if observedLHS.Has(pe) {
+				errs = append(errs, errorf("lhs: duplicate entries for key %v", pe.String())...)
+				continue
+			}
+			observedLHS.Insert(pe)
+			w2 := w.prepareDescent(pe, t.ElementType)
+			w2.lhs = value.Value(child)
+			if rchild, ok := observedRHS.Get(pe); ok {
+				w2.rhs = rchild
+			}
+			errs = append(errs, w2.merge(pe.String)...)
+			if w2.out != nil {
+				out = append(out, *w2.out)
+			}
+			w.finishDescent(w2)
+		}
+	}
+
+	for _, pe := range rhsOrder {
+		if observedLHS.Has(pe) {
+			continue
+		}
+		value, _ := observedRHS.Get(pe)
+		w2 := w.prepareDescent(pe, t.ElementType)
+		w2.rhs = value
+		errs = append(errs, w2.merge(pe.String)...)
+		if w2.out != nil {
+			out = append(out, *w2.out)
+		}
+		w.finishDescent(w2)
+	}
+
+	if len(out) > 0 {
+		i := interface{}(out)
+		w.out = &i
+	}
+
+	return errs
+}
+
+func (w *mergingWalker) derefList(prefix string, v value.Value) (value.List, ValidationErrors) {
+	if v == nil {
+		return nil, nil
+	}
+	l, err := listValue(w.allocator, v)
+	if err != nil {
+		return nil, errorf("%v: %v", prefix, err)
+	}
+	return l, nil
+}
+
+func (w *mergingWalker) doList(t *schema.List) (errs ValidationErrors) {
+	lhs, _ := w.derefList("lhs: ", w.lhs)
+	if lhs != nil {
+		defer w.allocator.Free(lhs)
+	}
+	rhs, _ := w.derefList("rhs: ", w.rhs)
+	if rhs != nil {
+		defer w.allocator.Free(rhs)
+	}
+
+	// If both lhs and rhs are empty/null, treat it as a
+	// leaf: this helps preserve the empty/null
+	// distinction.
+	emptyPromoteToLeaf := (lhs == nil || lhs.Length() == 0) && (rhs == nil || rhs.Length() == 0)
+
+	if t.ElementRelationship == schema.Atomic || emptyPromoteToLeaf {
+		w.doLeaf()
+		return nil
+	}
+
+	if lhs == nil && rhs == nil {
+		return nil
+	}
+
+	errs = w.visitListItems(t, lhs, rhs)
+
+	return errs
+}
+
+func (w *mergingWalker) visitMapItem(t *schema.Map, out map[string]interface{}, key string, lhs, rhs value.Value) (errs ValidationErrors) {
+	fieldType := t.ElementType
+	if sf, ok := t.FindField(key); ok {
+		fieldType = sf.Type
+	}
+	pe := fieldpath.PathElement{FieldName: &key}
+	w2 := w.prepareDescent(pe, fieldType)
+	w2.lhs = lhs
+	w2.rhs = rhs
+	errs = append(errs, w2.merge(pe.String)...)
+	if w2.out != nil {
+		out[key] = *w2.out
+	}
+	w.finishDescent(w2)
+	return errs
+}
+
+func (w *mergingWalker) visitMapItems(t *schema.Map, lhs, rhs value.Map) (errs ValidationErrors) {
+	out := map[string]interface{}{}
+
+	value.MapZipUsing(w.allocator, lhs, rhs, value.Unordered, func(key string, lhsValue, rhsValue value.Value) bool {
+		errs = append(errs, w.visitMapItem(t, out, key, lhsValue, rhsValue)...)
+		return true
+	})
+	if len(out) > 0 {
+		i := interface{}(out)
+		w.out = &i
+	}
+
+	return errs
+}
+
+func (w *mergingWalker) doMap(t *schema.Map) (errs ValidationErrors) {
+	lhs, _ := w.derefMap("lhs: ", w.lhs)
+	if lhs != nil {
+		defer w.allocator.Free(lhs)
+	}
+	rhs, _ := w.derefMap("rhs: ", w.rhs)
+	if rhs != nil {
+		defer w.allocator.Free(rhs)
+	}
+	// If both lhs and rhs are empty/null, treat it as a
+	// leaf: this helps preserve the empty/null
+	// distinction.
+	emptyPromoteToLeaf := (lhs == nil || lhs.Empty()) && (rhs == nil || rhs.Empty())
+
+	if t.ElementRelationship == schema.Atomic || emptyPromoteToLeaf {
+		w.doLeaf()
+		return nil
+	}
+
+	if lhs == nil && rhs == nil {
+		return nil
+	}
+
+	errs = append(errs, w.visitMapItems(t, lhs, rhs)...)
+
+	return errs
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/parser.go

@@ -0,0 +1,151 @@
+/*
+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 typed
+
+import (
+	"fmt"
+
+	yaml "gopkg.in/yaml.v2"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// YAMLObject is an object encoded in YAML.
+type YAMLObject string
+
+// Parser implements YAMLParser and allows introspecting the schema.
+type Parser struct {
+	Schema schema.Schema
+}
+
+// create builds an unvalidated parser.
+func create(s YAMLObject) (*Parser, error) {
+	p := Parser{}
+	err := yaml.Unmarshal([]byte(s), &p.Schema)
+	return &p, err
+}
+
+func createOrDie(schema YAMLObject) *Parser {
+	p, err := create(schema)
+	if err != nil {
+		panic(fmt.Errorf("failed to create parser: %v", err))
+	}
+	return p
+}
+
+var ssParser = createOrDie(YAMLObject(schema.SchemaSchemaYAML))
+
+// NewParser will build a YAMLParser from a schema. The schema is validated.
+func NewParser(schema YAMLObject) (*Parser, error) {
+	_, err := ssParser.Type("schema").FromYAML(schema)
+	if err != nil {
+		return nil, fmt.Errorf("unable to validate schema: %v", err)
+	}
+	p, err := create(schema)
+	if err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// TypeNames returns a list of types this parser understands.
+func (p *Parser) TypeNames() (names []string) {
+	for _, td := range p.Schema.Types {
+		names = append(names, td.Name)
+	}
+	return names
+}
+
+// Type returns a helper which can produce objects of the given type. Any
+// errors are deferred until a further function is called.
+func (p *Parser) Type(name string) ParseableType {
+	return ParseableType{
+		Schema:  &p.Schema,
+		TypeRef: schema.TypeRef{NamedType: &name},
+	}
+}
+
+// ParseableType allows for easy production of typed objects.
+type ParseableType struct {
+	TypeRef schema.TypeRef
+	Schema  *schema.Schema
+}
+
+// IsValid return true if p's schema and typename are valid.
+func (p ParseableType) IsValid() bool {
+	_, ok := p.Schema.Resolve(p.TypeRef)
+	return ok
+}
+
+// FromYAML parses a yaml string into an object with the current schema
+// and the type "typename" or an error if validation fails.
+func (p ParseableType) FromYAML(object YAMLObject) (*TypedValue, error) {
+	var v interface{}
+	err := yaml.Unmarshal([]byte(object), &v)
+	if err != nil {
+		return nil, err
+	}
+	return AsTyped(value.NewValueInterface(v), p.Schema, p.TypeRef)
+}
+
+// FromUnstructured converts a go "interface{}" type, typically an
+// unstructured object in Kubernetes world, to a TypedValue. It returns an
+// error if the resulting object fails schema validation.
+// The provided interface{} must be one of: map[string]interface{},
+// map[interface{}]interface{}, []interface{}, int types, float types,
+// string or boolean. Nested interface{} must also be one of these types.
+func (p ParseableType) FromUnstructured(in interface{}) (*TypedValue, error) {
+	return AsTyped(value.NewValueInterface(in), p.Schema, p.TypeRef)
+}
+
+// FromStructured converts a go "interface{}" type, typically an structured object in
+// Kubernetes, to a TypedValue. It will return an error if the resulting object fails
+// schema validation. The provided "interface{}" value must be a pointer so that the
+// value can be modified via reflection. The provided "interface{}" may contain structs
+// and types that are converted to Values by the jsonMarshaler interface.
+func (p ParseableType) FromStructured(in interface{}) (*TypedValue, error) {
+	v, err := value.NewValueReflect(in)
+	if err != nil {
+		return nil, fmt.Errorf("error creating struct value reflector: %v", err)
+	}
+	return AsTyped(v, p.Schema, p.TypeRef)
+}
+
+// DeducedParseableType is a ParseableType that deduces the type from
+// the content of the object.
+var DeducedParseableType ParseableType = createOrDie(YAMLObject(`types:
+- name: __untyped_atomic_
+  scalar: untyped
+  list:
+    elementType:
+      namedType: __untyped_atomic_
+    elementRelationship: atomic
+  map:
+    elementType:
+      namedType: __untyped_atomic_
+    elementRelationship: atomic
+- name: __untyped_deduced_
+  scalar: untyped
+  list:
+    elementType:
+      namedType: __untyped_atomic_
+    elementRelationship: atomic
+  map:
+    elementType:
+      namedType: __untyped_deduced_
+    elementRelationship: separable
+`)).Type("__untyped_deduced_")

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/reconcile_schema.go

@@ -0,0 +1,295 @@
+/*
+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 typed
+
+import (
+	"fmt"
+	"sync"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+)
+
+var fmPool = sync.Pool{
+	New: func() interface{} { return &reconcileWithSchemaWalker{} },
+}
+
+func (v *reconcileWithSchemaWalker) finished() {
+	v.fieldSet = nil
+	v.schema = nil
+	v.value = nil
+	v.typeRef = schema.TypeRef{}
+	v.path = nil
+	v.toRemove = nil
+	v.toAdd = nil
+	fmPool.Put(v)
+}
+
+type reconcileWithSchemaWalker struct {
+	value  *TypedValue    // root of the live object
+	schema *schema.Schema // root of the live schema
+
+	// state of node being visited by walker
+	fieldSet *fieldpath.Set
+	typeRef  schema.TypeRef
+	path     fieldpath.Path
+	isAtomic bool
+
+	// the accumulated diff to perform to apply reconciliation
+	toRemove *fieldpath.Set // paths to remove recursively
+	toAdd    *fieldpath.Set // paths to add after any removals
+
+	// Allocate only as many walkers as needed for the depth by storing them here.
+	spareWalkers *[]*reconcileWithSchemaWalker
+}
+
+func (v *reconcileWithSchemaWalker) prepareDescent(pe fieldpath.PathElement, tr schema.TypeRef) *reconcileWithSchemaWalker {
+	if v.spareWalkers == nil {
+		// first descent.
+		v.spareWalkers = &[]*reconcileWithSchemaWalker{}
+	}
+	var v2 *reconcileWithSchemaWalker
+	if n := len(*v.spareWalkers); n > 0 {
+		v2, *v.spareWalkers = (*v.spareWalkers)[n-1], (*v.spareWalkers)[:n-1]
+	} else {
+		v2 = &reconcileWithSchemaWalker{}
+	}
+	*v2 = *v
+	v2.typeRef = tr
+	v2.path = append(v.path, pe)
+	v2.value = v.value
+	return v2
+}
+
+func (v *reconcileWithSchemaWalker) finishDescent(v2 *reconcileWithSchemaWalker) {
+	v2.fieldSet = nil
+	v2.schema = nil
+	v2.value = nil
+	v2.typeRef = schema.TypeRef{}
+	if cap(v2.path) < 20 { // recycle slices that do not have unexpectedly high capacity
+		v2.path = v2.path[:0]
+	} else {
+		v2.path = nil
+	}
+
+	// merge any accumulated changes into parent walker
+	if v2.toRemove != nil {
+		if v.toRemove == nil {
+			v.toRemove = v2.toRemove
+		} else {
+			v.toRemove = v.toRemove.Union(v2.toRemove)
+		}
+	}
+	if v2.toAdd != nil {
+		if v.toAdd == nil {
+			v.toAdd = v2.toAdd
+		} else {
+			v.toAdd = v.toAdd.Union(v2.toAdd)
+		}
+	}
+	v2.toRemove = nil
+	v2.toAdd = nil
+
+	// if the descent caused a realloc, ensure that we reuse the buffer
+	// for the next sibling.
+	*v.spareWalkers = append(*v.spareWalkers, v2)
+}
+
+// ReconcileFieldSetWithSchema reconciles the a field set with any changes to the
+//// object's schema since the field set was written. Returns the reconciled field set, or nil of
+// no changes were made to the field set.
+//
+// Supports:
+// - changing types from atomic to granular
+// - changing types from granular to atomic
+func ReconcileFieldSetWithSchema(fieldset *fieldpath.Set, tv *TypedValue) (*fieldpath.Set, error) {
+	v := fmPool.Get().(*reconcileWithSchemaWalker)
+	v.fieldSet = fieldset
+	v.value = tv
+
+	v.schema = tv.schema
+	v.typeRef = tv.typeRef
+
+	// We don't reconcile deduced types, which are primarily for use by unstructured CRDs. Deduced
+	// types do not support atomic or granular tags. Nor does the dynamic schema deduction
+	// interact well with the reconcile logic.
+	if v.schema == DeducedParseableType.Schema {
+		return nil, nil
+	}
+
+	defer v.finished()
+	errs := v.reconcile()
+
+	if len(errs) > 0 {
+		return nil, fmt.Errorf("errors reconciling field set with schema: %s", errs.Error())
+	}
+
+	// If there are any accumulated changes, apply them
+	if v.toAdd != nil || v.toRemove != nil {
+		out := v.fieldSet
+		if v.toRemove != nil {
+			out = out.RecursiveDifference(v.toRemove)
+		}
+		if v.toAdd != nil {
+			out = out.Union(v.toAdd)
+		}
+		return out, nil
+	}
+	return nil, nil
+}
+
+func (v *reconcileWithSchemaWalker) reconcile() (errs ValidationErrors) {
+	a, ok := v.schema.Resolve(v.typeRef)
+	if !ok {
+		errs = append(errs, errorf("could not resolve %v", v.typeRef)...)
+		return
+	}
+	return handleAtom(a, v.typeRef, v)
+}
+
+func (v *reconcileWithSchemaWalker) doScalar(_ *schema.Scalar) (errs ValidationErrors) {
+	return errs
+}
+
+func (v *reconcileWithSchemaWalker) visitListItems(t *schema.List, element *fieldpath.Set) (errs ValidationErrors) {
+	handleElement := func(pe fieldpath.PathElement, isMember bool) {
+		var hasChildren bool
+		v2 := v.prepareDescent(pe, t.ElementType)
+		v2.fieldSet, hasChildren = element.Children.Get(pe)
+		v2.isAtomic = isMember && !hasChildren
+		errs = append(errs, v2.reconcile()...)
+		v.finishDescent(v2)
+	}
+	element.Children.Iterate(func(pe fieldpath.PathElement) {
+		if element.Members.Has(pe) {
+			return
+		}
+		handleElement(pe, false)
+	})
+	element.Members.Iterate(func(pe fieldpath.PathElement) {
+		handleElement(pe, true)
+	})
+	return errs
+}
+
+func (v *reconcileWithSchemaWalker) doList(t *schema.List) (errs ValidationErrors) {
+	// reconcile lists changed from granular to atomic
+	if !v.isAtomic && t.ElementRelationship == schema.Atomic {
+		v.toRemove = fieldpath.NewSet(v.path) // remove all root and all children fields
+		v.toAdd = fieldpath.NewSet(v.path)    // add the root of the atomic
+		return errs
+	}
+	// reconcile lists changed from atomic to granular
+	if v.isAtomic && t.ElementRelationship == schema.Associative {
+		v.toAdd, errs = buildGranularFieldSet(v.path, v.value)
+		if errs != nil {
+			return errs
+		}
+	}
+	if v.fieldSet != nil {
+		errs = v.visitListItems(t, v.fieldSet)
+	}
+	return errs
+}
+
+func (v *reconcileWithSchemaWalker) visitMapItems(t *schema.Map, element *fieldpath.Set) (errs ValidationErrors) {
+	handleElement := func(pe fieldpath.PathElement, isMember bool) {
+		var hasChildren bool
+		if tr, ok := typeRefAtPath(t, pe); ok { // ignore fields not in the schema
+			v2 := v.prepareDescent(pe, tr)
+			v2.fieldSet, hasChildren = element.Children.Get(pe)
+			v2.isAtomic = isMember && !hasChildren
+			errs = append(errs, v2.reconcile()...)
+			v.finishDescent(v2)
+		}
+	}
+	element.Children.Iterate(func(pe fieldpath.PathElement) {
+		if element.Members.Has(pe) {
+			return
+		}
+		handleElement(pe, false)
+	})
+	element.Members.Iterate(func(pe fieldpath.PathElement) {
+		handleElement(pe, true)
+	})
+
+	return errs
+}
+
+func (v *reconcileWithSchemaWalker) doMap(t *schema.Map) (errs ValidationErrors) {
+	// reconcile maps and structs changed from granular to atomic
+	if !v.isAtomic && t.ElementRelationship == schema.Atomic {
+		if v.fieldSet != nil && v.fieldSet.Size() > 0 {
+			v.toRemove = fieldpath.NewSet(v.path) // remove all root and all children fields
+			v.toAdd = fieldpath.NewSet(v.path)    // add the root of the atomic
+		}
+		return errs
+	}
+	// reconcile maps changed from atomic to granular
+	if v.isAtomic && (t.ElementRelationship == schema.Separable || t.ElementRelationship == "") {
+		v.toAdd, errs = buildGranularFieldSet(v.path, v.value)
+		if errs != nil {
+			return errs
+		}
+	}
+	if v.fieldSet != nil {
+		errs = v.visitMapItems(t, v.fieldSet)
+	}
+	return errs
+}
+
+func buildGranularFieldSet(path fieldpath.Path, value *TypedValue) (*fieldpath.Set, ValidationErrors) {
+
+	valueFieldSet, err := value.ToFieldSet()
+	if err != nil {
+		return nil, errorf("toFieldSet: %v", err)
+	}
+	if valueFieldSetAtPath, ok := fieldSetAtPath(valueFieldSet, path); ok {
+		result := fieldpath.NewSet(path)
+		resultAtPath := descendToPath(result, path)
+		*resultAtPath = *valueFieldSetAtPath
+		return result, nil
+	}
+	return nil, nil
+}
+
+func fieldSetAtPath(node *fieldpath.Set, path fieldpath.Path) (*fieldpath.Set, bool) {
+	ok := true
+	for _, pe := range path {
+		if node, ok = node.Children.Get(pe); !ok {
+			break
+		}
+	}
+	return node, ok
+}
+
+func descendToPath(node *fieldpath.Set, path fieldpath.Path) *fieldpath.Set {
+	for _, pe := range path {
+		node = node.Children.Descend(pe)
+	}
+	return node
+}
+
+func typeRefAtPath(t *schema.Map, pe fieldpath.PathElement) (schema.TypeRef, bool) {
+	tr := t.ElementType
+	if pe.FieldName != nil {
+		if sf, ok := t.FindField(*pe.FieldName); ok {
+			tr = sf.Type
+		}
+	}
+	return tr, tr != schema.TypeRef{}
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/remove.go

@@ -0,0 +1,140 @@
+/*
+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 typed
+
+import (
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+type removingWalker struct {
+	value         value.Value
+	out           interface{}
+	schema        *schema.Schema
+	toRemove      *fieldpath.Set
+	allocator     value.Allocator
+	shouldExtract bool
+}
+
+// removeItemsWithSchema will walk the given value and look for items from the toRemove set.
+// Depending on whether shouldExtract is set true or false, it will return a modified version
+// of the input value with either:
+// 1. only the items in the toRemove set (when shouldExtract is true) or
+// 2. the items from the toRemove set removed from the value (when shouldExtract is false).
+func removeItemsWithSchema(val value.Value, toRemove *fieldpath.Set, schema *schema.Schema, typeRef schema.TypeRef, shouldExtract bool) value.Value {
+	w := &removingWalker{
+		value:         val,
+		schema:        schema,
+		toRemove:      toRemove,
+		allocator:     value.NewFreelistAllocator(),
+		shouldExtract: shouldExtract,
+	}
+	resolveSchema(schema, typeRef, val, w)
+	return value.NewValueInterface(w.out)
+}
+
+func (w *removingWalker) doScalar(t *schema.Scalar) ValidationErrors {
+	w.out = w.value.Unstructured()
+	return nil
+}
+
+func (w *removingWalker) doList(t *schema.List) (errs ValidationErrors) {
+	l := w.value.AsListUsing(w.allocator)
+	defer w.allocator.Free(l)
+	// If list is null, empty, or atomic just return
+	if l == nil || l.Length() == 0 || t.ElementRelationship == schema.Atomic {
+		return nil
+	}
+
+	var newItems []interface{}
+	iter := l.RangeUsing(w.allocator)
+	defer w.allocator.Free(iter)
+	for iter.Next() {
+		i, item := iter.Item()
+		// Ignore error because we have already validated this list
+		pe, _ := listItemToPathElement(w.allocator, w.schema, t, i, item)
+		path, _ := fieldpath.MakePath(pe)
+		// save items on the path when we shouldExtract
+		// but ignore them when we are removing (i.e. !w.shouldExtract)
+		if w.toRemove.Has(path) {
+			if w.shouldExtract {
+				newItems = append(newItems, item.Unstructured())
+			} else {
+				continue
+			}
+		}
+		if subset := w.toRemove.WithPrefix(pe); !subset.Empty() {
+			item = removeItemsWithSchema(item, subset, w.schema, t.ElementType, w.shouldExtract)
+		} else {
+			// don't save items not on the path when we shouldExtract.
+			if w.shouldExtract {
+				continue
+			}
+		}
+		newItems = append(newItems, item.Unstructured())
+	}
+	if len(newItems) > 0 {
+		w.out = newItems
+	}
+	return nil
+}
+
+func (w *removingWalker) doMap(t *schema.Map) ValidationErrors {
+	m := w.value.AsMapUsing(w.allocator)
+	if m != nil {
+		defer w.allocator.Free(m)
+	}
+	// If map is null, empty, or atomic just return
+	if m == nil || m.Empty() || t.ElementRelationship == schema.Atomic {
+		return nil
+	}
+
+	fieldTypes := map[string]schema.TypeRef{}
+	for _, structField := range t.Fields {
+		fieldTypes[structField.Name] = structField.Type
+	}
+
+	newMap := map[string]interface{}{}
+	m.Iterate(func(k string, val value.Value) bool {
+		pe := fieldpath.PathElement{FieldName: &k}
+		path, _ := fieldpath.MakePath(pe)
+		fieldType := t.ElementType
+		if ft, ok := fieldTypes[k]; ok {
+			fieldType = ft
+		}
+		// save values on the path when we shouldExtract
+		// but ignore them when we are removing (i.e. !w.shouldExtract)
+		if w.toRemove.Has(path) {
+			if w.shouldExtract {
+				newMap[k] = val.Unstructured()
+			}
+			return true
+		}
+		if subset := w.toRemove.WithPrefix(pe); !subset.Empty() {
+			val = removeItemsWithSchema(val, subset, w.schema, fieldType, w.shouldExtract)
+		} else {
+			// don't save values not on the path when we shouldExtract.
+			if w.shouldExtract {
+				return true
+			}
+		}
+		newMap[k] = val.Unstructured()
+		return true
+	})
+	if len(newMap) > 0 {
+		w.out = newMap
+	}
+	return nil
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/tofieldset.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 typed
+
+import (
+	"sync"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+var tPool = sync.Pool{
+	New: func() interface{} { return &toFieldSetWalker{} },
+}
+
+func (tv TypedValue) toFieldSetWalker() *toFieldSetWalker {
+	v := tPool.Get().(*toFieldSetWalker)
+	v.value = tv.value
+	v.schema = tv.schema
+	v.typeRef = tv.typeRef
+	v.set = &fieldpath.Set{}
+	v.allocator = value.NewFreelistAllocator()
+	return v
+}
+
+func (v *toFieldSetWalker) finished() {
+	v.schema = nil
+	v.typeRef = schema.TypeRef{}
+	v.path = nil
+	v.set = nil
+	tPool.Put(v)
+}
+
+type toFieldSetWalker struct {
+	value   value.Value
+	schema  *schema.Schema
+	typeRef schema.TypeRef
+
+	set  *fieldpath.Set
+	path fieldpath.Path
+
+	// Allocate only as many walkers as needed for the depth by storing them here.
+	spareWalkers *[]*toFieldSetWalker
+	allocator    value.Allocator
+}
+
+func (v *toFieldSetWalker) prepareDescent(pe fieldpath.PathElement, tr schema.TypeRef) *toFieldSetWalker {
+	if v.spareWalkers == nil {
+		// first descent.
+		v.spareWalkers = &[]*toFieldSetWalker{}
+	}
+	var v2 *toFieldSetWalker
+	if n := len(*v.spareWalkers); n > 0 {
+		v2, *v.spareWalkers = (*v.spareWalkers)[n-1], (*v.spareWalkers)[:n-1]
+	} else {
+		v2 = &toFieldSetWalker{}
+	}
+	*v2 = *v
+	v2.typeRef = tr
+	v2.path = append(v2.path, pe)
+	return v2
+}
+
+func (v *toFieldSetWalker) finishDescent(v2 *toFieldSetWalker) {
+	// if the descent caused a realloc, ensure that we reuse the buffer
+	// for the next sibling.
+	v.path = v2.path[:len(v2.path)-1]
+	*v.spareWalkers = append(*v.spareWalkers, v2)
+}
+
+func (v *toFieldSetWalker) toFieldSet() ValidationErrors {
+	return resolveSchema(v.schema, v.typeRef, v.value, v)
+}
+
+func (v *toFieldSetWalker) doScalar(t *schema.Scalar) ValidationErrors {
+	v.set.Insert(v.path)
+
+	return nil
+}
+
+func (v *toFieldSetWalker) visitListItems(t *schema.List, list value.List) (errs ValidationErrors) {
+	for i := 0; i < list.Length(); i++ {
+		child := list.At(i)
+		pe, _ := listItemToPathElement(v.allocator, v.schema, t, i, child)
+		v2 := v.prepareDescent(pe, t.ElementType)
+		v2.value = child
+		errs = append(errs, v2.toFieldSet()...)
+
+		v2.set.Insert(v2.path)
+		v.finishDescent(v2)
+	}
+	return errs
+}
+
+func (v *toFieldSetWalker) doList(t *schema.List) (errs ValidationErrors) {
+	list, _ := listValue(v.allocator, v.value)
+	if list != nil {
+		defer v.allocator.Free(list)
+	}
+	if t.ElementRelationship == schema.Atomic {
+		v.set.Insert(v.path)
+		return nil
+	}
+
+	if list == nil {
+		return nil
+	}
+
+	errs = v.visitListItems(t, list)
+
+	return errs
+}
+
+func (v *toFieldSetWalker) visitMapItems(t *schema.Map, m value.Map) (errs ValidationErrors) {
+	m.Iterate(func(key string, val value.Value) bool {
+		pe := fieldpath.PathElement{FieldName: &key}
+
+		tr := t.ElementType
+		if sf, ok := t.FindField(key); ok {
+			tr = sf.Type
+		}
+		v2 := v.prepareDescent(pe, tr)
+		v2.value = val
+		errs = append(errs, v2.toFieldSet()...)
+		if val.IsNull() || (val.IsMap() && val.AsMap().Length() == 0) {
+			v2.set.Insert(v2.path)
+		} else if _, ok := t.FindField(key); !ok {
+			v2.set.Insert(v2.path)
+		}
+		v.finishDescent(v2)
+		return true
+	})
+	return errs
+}
+
+func (v *toFieldSetWalker) doMap(t *schema.Map) (errs ValidationErrors) {
+	m, _ := mapValue(v.allocator, v.value)
+	if m != nil {
+		defer v.allocator.Free(m)
+	}
+	if t.ElementRelationship == schema.Atomic {
+		v.set.Insert(v.path)
+		return nil
+	}
+
+	if m == nil {
+		return nil
+	}
+
+	errs = v.visitMapItems(t, m)
+
+	return errs
+}

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

@@ -0,0 +1,321 @@
+/*
+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 typed
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+// AsTyped accepts a value and a type and returns a TypedValue. 'v' must have
+// type 'typeName' in the schema. An error is returned if the v doesn't conform
+// to the schema.
+func AsTyped(v value.Value, s *schema.Schema, typeRef schema.TypeRef) (*TypedValue, error) {
+	tv := &TypedValue{
+		value:   v,
+		typeRef: typeRef,
+		schema:  s,
+	}
+	if err := tv.Validate(); err != nil {
+		return nil, err
+	}
+	return tv, nil
+}
+
+// AsTypeUnvalidated is just like AsTyped, but doesn't validate that the type
+// conforms to the schema, for cases where that has already been checked or
+// where you're going to call a method that validates as a side-effect (like
+// ToFieldSet).
+func AsTypedUnvalidated(v value.Value, s *schema.Schema, typeRef schema.TypeRef) *TypedValue {
+	tv := &TypedValue{
+		value:   v,
+		typeRef: typeRef,
+		schema:  s,
+	}
+	return tv
+}
+
+// TypedValue is a value of some specific type.
+type TypedValue struct {
+	value   value.Value
+	typeRef schema.TypeRef
+	schema  *schema.Schema
+}
+
+// TypeRef is the type of the value.
+func (tv TypedValue) TypeRef() schema.TypeRef {
+	return tv.typeRef
+}
+
+// AsValue removes the type from the TypedValue and only keeps the value.
+func (tv TypedValue) AsValue() value.Value {
+	return tv.value
+}
+
+// Schema gets the schema from the TypedValue.
+func (tv TypedValue) Schema() *schema.Schema {
+	return tv.schema
+}
+
+// Validate returns an error with a list of every spec violation.
+func (tv TypedValue) Validate() error {
+	w := tv.walker()
+	defer w.finished()
+	if errs := w.validate(nil); len(errs) != 0 {
+		return errs
+	}
+	return nil
+}
+
+// ToFieldSet creates a set containing every leaf field and item mentioned, or
+// validation errors, if any were encountered.
+func (tv TypedValue) ToFieldSet() (*fieldpath.Set, error) {
+	w := tv.toFieldSetWalker()
+	defer w.finished()
+	if errs := w.toFieldSet(); len(errs) != 0 {
+		return nil, errs
+	}
+	return w.set, nil
+}
+
+// Merge returns the result of merging tv and pso ("partially specified
+// object") together. Of note:
+//  * No fields can be removed by this operation.
+//  * If both tv and pso specify a given leaf field, the result will keep pso's
+//    value.
+//  * Container typed elements will have their items ordered:
+//    * like tv, if pso doesn't change anything in the container
+//    * like pso, if pso does change something in the container.
+// tv and pso must both be of the same type (their Schema and TypeRef must
+// match), or an error will be returned. Validation errors will be returned if
+// the objects don't conform to the schema.
+func (tv TypedValue) Merge(pso *TypedValue) (*TypedValue, error) {
+	return merge(&tv, pso, ruleKeepRHS, nil)
+}
+
+// Compare compares the two objects. See the comments on the `Comparison`
+// struct for details on the return value.
+//
+// tv and rhs must both be of the same type (their Schema and TypeRef must
+// match), or an error will be returned. Validation errors will be returned if
+// the objects don't conform to the schema.
+func (tv TypedValue) Compare(rhs *TypedValue) (c *Comparison, err error) {
+	c = &Comparison{
+		Removed:  fieldpath.NewSet(),
+		Modified: fieldpath.NewSet(),
+		Added:    fieldpath.NewSet(),
+	}
+	_, err = merge(&tv, rhs, func(w *mergingWalker) {
+		if w.lhs == nil {
+			c.Added.Insert(w.path)
+		} else if w.rhs == nil {
+			c.Removed.Insert(w.path)
+		} else if !value.Equals(w.rhs, w.lhs) {
+			// TODO: Equality is not sufficient for this.
+			// Need to implement equality check on the value type.
+			c.Modified.Insert(w.path)
+		}
+	}, func(w *mergingWalker) {
+		if w.lhs == nil {
+			c.Added.Insert(w.path)
+		} else if w.rhs == nil {
+			c.Removed.Insert(w.path)
+		}
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}
+
+// RemoveItems removes each provided list or map item from the value.
+func (tv TypedValue) RemoveItems(items *fieldpath.Set) *TypedValue {
+	tv.value = removeItemsWithSchema(tv.value, items, tv.schema, tv.typeRef, false)
+	return &tv
+}
+
+// ExtractItems returns a value with only the provided list or map items extracted from the value.
+func (tv TypedValue) ExtractItems(items *fieldpath.Set) *TypedValue {
+	tv.value = removeItemsWithSchema(tv.value, items, tv.schema, tv.typeRef, true)
+	return &tv
+}
+
+// NormalizeUnions takes the new object and normalizes the union:
+// - If discriminator changed to non-nil, and a new field has been added
+// that doesn't match, an error is returned,
+// - If discriminator hasn't changed and two fields or more are set, an
+// error is returned,
+// - If discriminator changed to non-nil, all other fields but the
+// discriminated one will be cleared,
+// - Otherwise, If only one field is left, update discriminator to that value.
+//
+// Please note: union behavior isn't finalized yet and this is still experimental.
+func (tv TypedValue) NormalizeUnions(new *TypedValue) (*TypedValue, error) {
+	var errs ValidationErrors
+	var normalizeFn = func(w *mergingWalker) {
+		if w.rhs != nil {
+			v := w.rhs.Unstructured()
+			w.out = &v
+		}
+		if err := normalizeUnions(w); err != nil {
+			errs = append(errs, errorf(err.Error())...)
+		}
+	}
+	out, mergeErrs := merge(&tv, new, func(w *mergingWalker) {}, normalizeFn)
+	if mergeErrs != nil {
+		errs = append(errs, mergeErrs.(ValidationErrors)...)
+	}
+	if len(errs) > 0 {
+		return nil, errs
+	}
+	return out, nil
+}
+
+// NormalizeUnionsApply specifically normalize unions on apply. It
+// validates that the applied union is correct (there should be no
+// ambiguity there), and clear the fields according to the sent intent.
+//
+// Please note: union behavior isn't finalized yet and this is still experimental.
+func (tv TypedValue) NormalizeUnionsApply(new *TypedValue) (*TypedValue, error) {
+	var errs ValidationErrors
+	var normalizeFn = func(w *mergingWalker) {
+		if w.rhs != nil {
+			v := w.rhs.Unstructured()
+			w.out = &v
+		}
+		if err := normalizeUnionsApply(w); err != nil {
+			errs = append(errs, errorf(err.Error())...)
+		}
+	}
+	out, mergeErrs := merge(&tv, new, func(w *mergingWalker) {}, normalizeFn)
+	if mergeErrs != nil {
+		errs = append(errs, mergeErrs.(ValidationErrors)...)
+	}
+	if len(errs) > 0 {
+		return nil, errs
+	}
+	return out, nil
+}
+
+func (tv TypedValue) Empty() *TypedValue {
+	tv.value = value.NewValueInterface(nil)
+	return &tv
+}
+
+var mwPool = sync.Pool{
+	New: func() interface{} { return &mergingWalker{} },
+}
+
+func merge(lhs, rhs *TypedValue, rule, postRule mergeRule) (*TypedValue, error) {
+	if lhs.schema != rhs.schema {
+		return nil, errorf("expected objects with types from the same schema")
+	}
+	if !lhs.typeRef.Equals(&rhs.typeRef) {
+		return nil, errorf("expected objects of the same type, but got %v and %v", lhs.typeRef, rhs.typeRef)
+	}
+
+	mw := mwPool.Get().(*mergingWalker)
+	defer func() {
+		mw.lhs = nil
+		mw.rhs = nil
+		mw.schema = nil
+		mw.typeRef = schema.TypeRef{}
+		mw.rule = nil
+		mw.postItemHook = nil
+		mw.out = nil
+		mw.inLeaf = false
+
+		mwPool.Put(mw)
+	}()
+
+	mw.lhs = lhs.value
+	mw.rhs = rhs.value
+	mw.schema = lhs.schema
+	mw.typeRef = lhs.typeRef
+	mw.rule = rule
+	mw.postItemHook = postRule
+	if mw.allocator == nil {
+		mw.allocator = value.NewFreelistAllocator()
+	}
+
+	errs := mw.merge(nil)
+	if len(errs) > 0 {
+		return nil, errs
+	}
+
+	out := &TypedValue{
+		schema:  lhs.schema,
+		typeRef: lhs.typeRef,
+	}
+	if mw.out != nil {
+		out.value = value.NewValueInterface(*mw.out)
+	}
+	return out, nil
+}
+
+// Comparison is the return value of a TypedValue.Compare() operation.
+//
+// No field will appear in more than one of the three fieldsets. If all of the
+// fieldsets are empty, then the objects must have been equal.
+type Comparison struct {
+	// Removed contains any fields removed by rhs (the right-hand-side
+	// object in the comparison).
+	Removed *fieldpath.Set
+	// Modified contains fields present in both objects but different.
+	Modified *fieldpath.Set
+	// Added contains any fields added by rhs.
+	Added *fieldpath.Set
+}
+
+// IsSame returns true if the comparison returned no changes (the two
+// compared objects are similar).
+func (c *Comparison) IsSame() bool {
+	return c.Removed.Empty() && c.Modified.Empty() && c.Added.Empty()
+}
+
+// String returns a human readable version of the comparison.
+func (c *Comparison) String() string {
+	bld := strings.Builder{}
+	if !c.Modified.Empty() {
+		bld.WriteString(fmt.Sprintf("- Modified Fields:\n%v\n", c.Modified))
+	}
+	if !c.Added.Empty() {
+		bld.WriteString(fmt.Sprintf("- Added Fields:\n%v\n", c.Added))
+	}
+	if !c.Removed.Empty() {
+		bld.WriteString(fmt.Sprintf("- Removed Fields:\n%v\n", c.Removed))
+	}
+	return bld.String()
+}
+
+// ExcludeFields fields from the compare recursively removes the fields
+// from the entire comparison
+func (c *Comparison) ExcludeFields(fields *fieldpath.Set) *Comparison {
+	if fields == nil || fields.Empty() {
+		return c
+	}
+	c.Removed = c.Removed.RecursiveDifference(fields)
+	c.Modified = c.Modified.RecursiveDifference(fields)
+	c.Added = c.Added.RecursiveDifference(fields)
+	return c
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/union.go

@@ -0,0 +1,276 @@
+/*
+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 typed
+
+import (
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+func normalizeUnions(w *mergingWalker) error {
+	atom, found := w.schema.Resolve(w.typeRef)
+	if !found {
+		panic(fmt.Sprintf("Unable to resolve schema in normalize union: %v/%v", w.schema, w.typeRef))
+	}
+	// Unions can only be in structures, and the struct must not have been removed
+	if atom.Map == nil || w.out == nil {
+		return nil
+	}
+
+	var old value.Map
+	if w.lhs != nil && !w.lhs.IsNull() {
+		old = w.lhs.AsMap()
+	}
+	for _, union := range atom.Map.Unions {
+		if err := newUnion(&union).Normalize(old, w.rhs.AsMap(), value.NewValueInterface(*w.out).AsMap()); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func normalizeUnionsApply(w *mergingWalker) error {
+	atom, found := w.schema.Resolve(w.typeRef)
+	if !found {
+		panic(fmt.Sprintf("Unable to resolve schema in normalize union: %v/%v", w.schema, w.typeRef))
+	}
+	// Unions can only be in structures, and the struct must not have been removed
+	if atom.Map == nil || w.out == nil {
+		return nil
+	}
+
+	var old value.Map
+	if w.lhs != nil && !w.lhs.IsNull() {
+		old = w.lhs.AsMap()
+	}
+
+	for _, union := range atom.Map.Unions {
+		out := value.NewValueInterface(*w.out)
+		if err := newUnion(&union).NormalizeApply(old, w.rhs.AsMap(), out.AsMap()); err != nil {
+			return err
+		}
+		*w.out = out.Unstructured()
+	}
+	return nil
+}
+
+type discriminated string
+type field string
+
+type discriminatedNames struct {
+	f2d map[field]discriminated
+	d2f map[discriminated]field
+}
+
+func newDiscriminatedName(f2d map[field]discriminated) discriminatedNames {
+	d2f := map[discriminated]field{}
+	for key, value := range f2d {
+		d2f[value] = key
+	}
+	return discriminatedNames{
+		f2d: f2d,
+		d2f: d2f,
+	}
+}
+
+func (dn discriminatedNames) toField(d discriminated) field {
+	if f, ok := dn.d2f[d]; ok {
+		return f
+	}
+	return field(d)
+}
+
+func (dn discriminatedNames) toDiscriminated(f field) discriminated {
+	if d, ok := dn.f2d[f]; ok {
+		return d
+	}
+	return discriminated(f)
+}
+
+type discriminator struct {
+	name string
+}
+
+func (d *discriminator) Set(m value.Map, v discriminated) {
+	if d == nil {
+		return
+	}
+	m.Set(d.name, value.NewValueInterface(string(v)))
+}
+
+func (d *discriminator) Get(m value.Map) discriminated {
+	if d == nil || m == nil {
+		return ""
+	}
+	val, ok := m.Get(d.name)
+	if !ok {
+		return ""
+	}
+	if !val.IsString() {
+		return ""
+	}
+	return discriminated(val.AsString())
+}
+
+type fieldsSet map[field]struct{}
+
+// newFieldsSet returns a map of the fields that are part of the union and are set
+// in the given map.
+func newFieldsSet(m value.Map, fields []field) fieldsSet {
+	if m == nil {
+		return nil
+	}
+	set := fieldsSet{}
+	for _, f := range fields {
+		if subField, ok := m.Get(string(f)); ok && !subField.IsNull() {
+			set.Add(f)
+		}
+	}
+	return set
+}
+
+func (fs fieldsSet) Add(f field) {
+	if fs == nil {
+		fs = map[field]struct{}{}
+	}
+	fs[f] = struct{}{}
+}
+
+func (fs fieldsSet) One() *field {
+	for f := range fs {
+		return &f
+	}
+	return nil
+}
+
+func (fs fieldsSet) Has(f field) bool {
+	_, ok := fs[f]
+	return ok
+}
+
+func (fs fieldsSet) List() []field {
+	fields := []field{}
+	for f := range fs {
+		fields = append(fields, f)
+	}
+	return fields
+}
+
+func (fs fieldsSet) Difference(o fieldsSet) fieldsSet {
+	n := fieldsSet{}
+	for f := range fs {
+		if !o.Has(f) {
+			n.Add(f)
+		}
+	}
+	return n
+}
+
+func (fs fieldsSet) String() string {
+	s := []string{}
+	for k := range fs {
+		s = append(s, string(k))
+	}
+	return strings.Join(s, ", ")
+}
+
+type union struct {
+	deduceInvalidDiscriminator bool
+	d                          *discriminator
+	dn                         discriminatedNames
+	f                          []field
+}
+
+func newUnion(su *schema.Union) *union {
+	u := &union{}
+	if su.Discriminator != nil {
+		u.d = &discriminator{name: *su.Discriminator}
+	}
+	f2d := map[field]discriminated{}
+	for _, f := range su.Fields {
+		u.f = append(u.f, field(f.FieldName))
+		f2d[field(f.FieldName)] = discriminated(f.DiscriminatorValue)
+	}
+	u.dn = newDiscriminatedName(f2d)
+	u.deduceInvalidDiscriminator = su.DeduceInvalidDiscriminator
+	return u
+}
+
+// clear removes all the fields in map that are part of the union, but
+// the one we decided to keep.
+func (u *union) clear(m value.Map, f field) {
+	for _, fieldName := range u.f {
+		if field(fieldName) != f {
+			m.Delete(string(fieldName))
+		}
+	}
+}
+
+func (u *union) Normalize(old, new, out value.Map) error {
+	os := newFieldsSet(old, u.f)
+	ns := newFieldsSet(new, u.f)
+	diff := ns.Difference(os)
+
+	if u.d.Get(old) != u.d.Get(new) && u.d.Get(new) != "" {
+		if len(diff) == 1 && u.d.Get(new) != u.dn.toDiscriminated(*diff.One()) {
+			return fmt.Errorf("discriminator (%v) and field changed (%v) don't match", u.d.Get(new), diff.One())
+		}
+		if len(diff) > 1 {
+			return fmt.Errorf("multiple new fields added: %v", diff)
+		}
+		u.clear(out, u.dn.toField(u.d.Get(new)))
+		return nil
+	}
+
+	if len(ns) > 1 {
+		return fmt.Errorf("multiple fields set without discriminator change: %v", ns)
+	}
+
+	// Set discriminiator if it needs to be deduced.
+	if u.deduceInvalidDiscriminator && len(ns) == 1 {
+		u.d.Set(out, u.dn.toDiscriminated(*ns.One()))
+	}
+
+	return nil
+}
+
+func (u *union) NormalizeApply(applied, merged, out value.Map) error {
+	as := newFieldsSet(applied, u.f)
+	if len(as) > 1 {
+		return fmt.Errorf("more than one field of union applied: %v", as)
+	}
+	if len(as) == 0 {
+		// None is set, just leave.
+		return nil
+	}
+	// We have exactly one, discriminiator must match if set
+	if u.d.Get(applied) != "" && u.d.Get(applied) != u.dn.toDiscriminated(*as.One()) {
+		return fmt.Errorf("applied discriminator (%v) doesn't match applied field (%v)", u.d.Get(applied), *as.One())
+	}
+
+	// Update discriminiator if needed
+	if u.deduceInvalidDiscriminator {
+		u.d.Set(out, u.dn.toDiscriminated(*as.One()))
+	}
+	// Clear others fields.
+	u.clear(out, *as.One())
+
+	return nil
+}

vendor/sigs.k8s.io/structured-merge-diff/v4/typed/validate.go

@@ -0,0 +1,195 @@
+/*
+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 typed
+
+import (
+	"sync"
+
+	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/v4/schema"
+	"sigs.k8s.io/structured-merge-diff/v4/value"
+)
+
+var vPool = sync.Pool{
+	New: func() interface{} { return &validatingObjectWalker{} },
+}
+
+func (tv TypedValue) walker() *validatingObjectWalker {
+	v := vPool.Get().(*validatingObjectWalker)
+	v.value = tv.value
+	v.schema = tv.schema
+	v.typeRef = tv.typeRef
+	if v.allocator == nil {
+		v.allocator = value.NewFreelistAllocator()
+	}
+	return v
+}
+
+func (v *validatingObjectWalker) finished() {
+	v.schema = nil
+	v.typeRef = schema.TypeRef{}
+	vPool.Put(v)
+}
+
+type validatingObjectWalker struct {
+	value   value.Value
+	schema  *schema.Schema
+	typeRef schema.TypeRef
+
+	// Allocate only as many walkers as needed for the depth by storing them here.
+	spareWalkers *[]*validatingObjectWalker
+	allocator    value.Allocator
+}
+
+func (v *validatingObjectWalker) prepareDescent(tr schema.TypeRef) *validatingObjectWalker {
+	if v.spareWalkers == nil {
+		// first descent.
+		v.spareWalkers = &[]*validatingObjectWalker{}
+	}
+	var v2 *validatingObjectWalker
+	if n := len(*v.spareWalkers); n > 0 {
+		v2, *v.spareWalkers = (*v.spareWalkers)[n-1], (*v.spareWalkers)[:n-1]
+	} else {
+		v2 = &validatingObjectWalker{}
+	}
+	*v2 = *v
+	v2.typeRef = tr
+	return v2
+}
+
+func (v *validatingObjectWalker) finishDescent(v2 *validatingObjectWalker) {
+	// if the descent caused a realloc, ensure that we reuse the buffer
+	// for the next sibling.
+	*v.spareWalkers = append(*v.spareWalkers, v2)
+}
+
+func (v *validatingObjectWalker) validate(prefixFn func() string) ValidationErrors {
+	return resolveSchema(v.schema, v.typeRef, v.value, v).WithLazyPrefix(prefixFn)
+}
+
+func validateScalar(t *schema.Scalar, v value.Value, prefix string) (errs ValidationErrors) {
+	if v == nil {
+		return nil
+	}
+	if v.IsNull() {
+		return nil
+	}
+	switch *t {
+	case schema.Numeric:
+		if !v.IsFloat() && !v.IsInt() {
+			// TODO: should the schema separate int and float?
+			return errorf("%vexpected numeric (int or float), got %T", prefix, v.Unstructured())
+		}
+	case schema.String:
+		if !v.IsString() {
+			return errorf("%vexpected string, got %#v", prefix, v)
+		}
+	case schema.Boolean:
+		if !v.IsBool() {
+			return errorf("%vexpected boolean, got %v", prefix, v)
+		}
+	}
+	return nil
+}
+
+func (v *validatingObjectWalker) doScalar(t *schema.Scalar) ValidationErrors {
+	if errs := validateScalar(t, v.value, ""); len(errs) > 0 {
+		return errs
+	}
+	return nil
+}
+
+func (v *validatingObjectWalker) visitListItems(t *schema.List, list value.List) (errs ValidationErrors) {
+	observedKeys := fieldpath.MakePathElementSet(list.Length())
+	for i := 0; i < list.Length(); i++ {
+		child := list.AtUsing(v.allocator, i)
+		defer v.allocator.Free(child)
+		var pe fieldpath.PathElement
+		if t.ElementRelationship != schema.Associative {
+			pe.Index = &i
+		} else {
+			var err error
+			pe, err = listItemToPathElement(v.allocator, v.schema, t, i, child)
+			if err != nil {
+				errs = append(errs, errorf("element %v: %v", i, err.Error())...)
+				// If we can't construct the path element, we can't
+				// even report errors deeper in the schema, so bail on
+				// this element.
+				return
+			}
+			if observedKeys.Has(pe) {
+				errs = append(errs, errorf("duplicate entries for key %v", pe.String())...)
+			}
+			observedKeys.Insert(pe)
+		}
+		v2 := v.prepareDescent(t.ElementType)
+		v2.value = child
+		errs = append(errs, v2.validate(pe.String)...)
+		v.finishDescent(v2)
+	}
+	return errs
+}
+
+func (v *validatingObjectWalker) doList(t *schema.List) (errs ValidationErrors) {
+	list, err := listValue(v.allocator, v.value)
+	if err != nil {
+		return errorf(err.Error())
+	}
+
+	if list == nil {
+		return nil
+	}
+
+	defer v.allocator.Free(list)
+	errs = v.visitListItems(t, list)
+
+	return errs
+}
+
+func (v *validatingObjectWalker) visitMapItems(t *schema.Map, m value.Map) (errs ValidationErrors) {
+	m.IterateUsing(v.allocator, func(key string, val value.Value) bool {
+		pe := fieldpath.PathElement{FieldName: &key}
+		tr := t.ElementType
+		if sf, ok := t.FindField(key); ok {
+			tr = sf.Type
+		} else if (t.ElementType == schema.TypeRef{}) {
+			errs = append(errs, errorf("field not declared in schema").WithPrefix(pe.String())...)
+			return false
+		}
+		v2 := v.prepareDescent(tr)
+		v2.value = val
+		// Giving pe.String as a parameter actually increases the allocations.
+		errs = append(errs, v2.validate(func() string { return pe.String() })...)
+		v.finishDescent(v2)
+		return true
+	})
+	return errs
+}
+
+func (v *validatingObjectWalker) doMap(t *schema.Map) (errs ValidationErrors) {
+	m, err := mapValue(v.allocator, v.value)
+	if err != nil {
+		return errorf(err.Error())
+	}
+	if m == nil {
+		return nil
+	}
+	defer v.allocator.Free(m)
+	errs = v.visitMapItems(t, m)
+
+	return errs
+}