1 files changed, 463 insertions, 0 deletions
diff --git a/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go
new file mode 100644
index 000000000..49e6dd169
--- /dev/null
+++ b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go
@@ -0,0 +1,463 @@
+/*
+Copyright 2020 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 value
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"sort"
+	"sync"
+	"sync/atomic"
+)
+
+// UnstructuredConverter defines how a type can be converted directly to unstructured.
+// Types that implement json.Marshaler may also optionally implement this interface to provide a more
+// direct and more efficient conversion. All types that choose to implement this interface must still
+// implement this same conversion via json.Marshaler.
+type UnstructuredConverter interface {
+	json.Marshaler // require that json.Marshaler is implemented
+
+	// ToUnstructured returns the unstructured representation.
+	ToUnstructured() interface{}
+}
+
+// TypeReflectCacheEntry keeps data gathered using reflection about how a type is converted to/from unstructured.
+type TypeReflectCacheEntry struct {
+	isJsonMarshaler        bool
+	ptrIsJsonMarshaler     bool
+	isJsonUnmarshaler      bool
+	ptrIsJsonUnmarshaler   bool
+	isStringConvertable    bool
+	ptrIsStringConvertable bool
+
+	structFields        map[string]*FieldCacheEntry
+	orderedStructFields []*FieldCacheEntry
+}
+
+// FieldCacheEntry keeps data gathered using reflection about how the field of a struct is converted to/from
+// unstructured.
+type FieldCacheEntry struct {
+	// JsonName returns the name of the field according to the json tags on the struct field.
+	JsonName string
+	// isOmitEmpty is true if the field has the json 'omitempty' tag.
+	isOmitEmpty bool
+	// fieldPath is a list of field indices (see FieldByIndex) to lookup the value of
+	// a field in a reflect.Value struct. The field indices in the list form a path used
+	// to traverse through intermediary 'inline' fields.
+	fieldPath [][]int
+
+	fieldType reflect.Type
+	TypeEntry *TypeReflectCacheEntry
+}
+
+func (f *FieldCacheEntry) CanOmit(fieldVal reflect.Value) bool {
+	return f.isOmitEmpty && (safeIsNil(fieldVal) || isZero(fieldVal))
+}
+
+// GetUsing returns the field identified by this FieldCacheEntry from the provided struct.
+func (f *FieldCacheEntry) GetFrom(structVal reflect.Value) reflect.Value {
+	// field might be nested within 'inline' structs
+	for _, elem := range f.fieldPath {
+		structVal = structVal.FieldByIndex(elem)
+	}
+	return structVal
+}
+
+var marshalerType = reflect.TypeOf(new(json.Marshaler)).Elem()
+var unmarshalerType = reflect.TypeOf(new(json.Unmarshaler)).Elem()
+var unstructuredConvertableType = reflect.TypeOf(new(UnstructuredConverter)).Elem()
+var defaultReflectCache = newReflectCache()
+
+// TypeReflectEntryOf returns the TypeReflectCacheEntry of the provided reflect.Type.
+func TypeReflectEntryOf(t reflect.Type) *TypeReflectCacheEntry {
+	cm := defaultReflectCache.get()
+	if record, ok := cm[t]; ok {
+		return record
+	}
+	updates := reflectCacheMap{}
+	result := typeReflectEntryOf(cm, t, updates)
+	if len(updates) > 0 {
+		defaultReflectCache.update(updates)
+	}
+	return result
+}
+
+// TypeReflectEntryOf returns all updates needed to add provided reflect.Type, and the types its fields transitively
+// depend on, to the cache.
+func typeReflectEntryOf(cm reflectCacheMap, t reflect.Type, updates reflectCacheMap) *TypeReflectCacheEntry {
+	if record, ok := cm[t]; ok {
+		return record
+	}
+	if record, ok := updates[t]; ok {
+		return record
+	}
+	typeEntry := &TypeReflectCacheEntry{
+		isJsonMarshaler:        t.Implements(marshalerType),
+		ptrIsJsonMarshaler:     reflect.PtrTo(t).Implements(marshalerType),
+		isJsonUnmarshaler:      reflect.PtrTo(t).Implements(unmarshalerType),
+		isStringConvertable:    t.Implements(unstructuredConvertableType),
+		ptrIsStringConvertable: reflect.PtrTo(t).Implements(unstructuredConvertableType),
+	}
+	if t.Kind() == reflect.Struct {
+		fieldEntries := map[string]*FieldCacheEntry{}
+		buildStructCacheEntry(t, fieldEntries, nil)
+		typeEntry.structFields = fieldEntries
+		sortedByJsonName := make([]*FieldCacheEntry, len(fieldEntries))
+		i := 0
+		for _, entry := range fieldEntries {
+			sortedByJsonName[i] = entry
+			i++
+		}
+		sort.Slice(sortedByJsonName, func(i, j int) bool {
+			return sortedByJsonName[i].JsonName < sortedByJsonName[j].JsonName
+		})
+		typeEntry.orderedStructFields = sortedByJsonName
+	}
+
+	// cyclic type references are allowed, so we must add the typeEntry to the updates map before resolving
+	// the field.typeEntry references, or creating them if they are not already in the cache
+	updates[t] = typeEntry
+
+	for _, field := range typeEntry.structFields {
+		if field.TypeEntry == nil {
+			field.TypeEntry = typeReflectEntryOf(cm, field.fieldType, updates)
+		}
+	}
+	return typeEntry
+}
+
+func buildStructCacheEntry(t reflect.Type, infos map[string]*FieldCacheEntry, fieldPath [][]int) {
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		jsonName, omit, isInline, isOmitempty := lookupJsonTags(field)
+		if omit {
+			continue
+		}
+		if isInline {
+			buildStructCacheEntry(field.Type, infos, append(fieldPath, field.Index))
+			continue
+		}
+		info := &FieldCacheEntry{JsonName: jsonName, isOmitEmpty: isOmitempty, fieldPath: append(fieldPath, field.Index), fieldType: field.Type}
+		infos[jsonName] = info
+	}
+}
+
+// Fields returns a map of JSON field name to FieldCacheEntry for structs, or nil for non-structs.
+func (e TypeReflectCacheEntry) Fields() map[string]*FieldCacheEntry {
+	return e.structFields
+}
+
+// Fields returns a map of JSON field name to FieldCacheEntry for structs, or nil for non-structs.
+func (e TypeReflectCacheEntry) OrderedFields() []*FieldCacheEntry {
+	return e.orderedStructFields
+}
+
+// CanConvertToUnstructured returns true if this TypeReflectCacheEntry can convert values of its type to unstructured.
+func (e TypeReflectCacheEntry) CanConvertToUnstructured() bool {
+	return e.isJsonMarshaler || e.ptrIsJsonMarshaler || e.isStringConvertable || e.ptrIsStringConvertable
+}
+
+// ToUnstructured converts the provided value to unstructured and returns it.
+func (e TypeReflectCacheEntry) ToUnstructured(sv reflect.Value) (interface{}, error) {
+	// This is based on https://github.com/kubernetes/kubernetes/blob/82c9e5c814eb7acc6cc0a090c057294d0667ad66/staging/src/k8s.io/apimachinery/pkg/runtime/converter.go#L505
+	// and is intended to replace it.
+
+	// Check if the object has a custom string converter and use it if available, since it is much more efficient
+	// than round tripping through json.
+	if converter, ok := e.getUnstructuredConverter(sv); ok {
+		return converter.ToUnstructured(), nil
+	}
+	// Check if the object has a custom JSON marshaller/unmarshaller.
+	if marshaler, ok := e.getJsonMarshaler(sv); ok {
+		if sv.Kind() == reflect.Ptr && sv.IsNil() {
+			// We're done - we don't need to store anything.
+			return nil, nil
+		}
+
+		data, err := marshaler.MarshalJSON()
+		if err != nil {
+			return nil, err
+		}
+		switch {
+		case len(data) == 0:
+			return nil, fmt.Errorf("error decoding from json: empty value")
+
+		case bytes.Equal(data, nullBytes):
+			// We're done - we don't need to store anything.
+			return nil, nil
+
+		case bytes.Equal(data, trueBytes):
+			return true, nil
+
+		case bytes.Equal(data, falseBytes):
+			return false, nil
+
+		case data[0] == '"':
+			var result string
+			err := unmarshal(data, &result)
+			if err != nil {
+				return nil, fmt.Errorf("error decoding string from json: %v", err)
+			}
+			return result, nil
+
+		case data[0] == '{':
+			result := make(map[string]interface{})
+			err := unmarshal(data, &result)
+			if err != nil {
+				return nil, fmt.Errorf("error decoding object from json: %v", err)
+			}
+			return result, nil
+
+		case data[0] == '[':
+			result := make([]interface{}, 0)
+			err := unmarshal(data, &result)
+			if err != nil {
+				return nil, fmt.Errorf("error decoding array from json: %v", err)
+			}
+			return result, nil
+
+		default:
+			var (
+				resultInt   int64
+				resultFloat float64
+				err         error
+			)
+			if err = unmarshal(data, &resultInt); err == nil {
+				return resultInt, nil
+			} else if err = unmarshal(data, &resultFloat); err == nil {
+				return resultFloat, nil
+			} else {
+				return nil, fmt.Errorf("error decoding number from json: %v", err)
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("provided type cannot be converted: %v", sv.Type())
+}
+
+// CanConvertFromUnstructured returns true if this TypeReflectCacheEntry can convert objects of the type from unstructured.
+func (e TypeReflectCacheEntry) CanConvertFromUnstructured() bool {
+	return e.isJsonUnmarshaler
+}
+
+// FromUnstructured converts the provided source value from unstructured into the provided destination value.
+func (e TypeReflectCacheEntry) FromUnstructured(sv, dv reflect.Value) error {
+	// TODO: this could be made much more efficient using direct conversions like
+	// UnstructuredConverter.ToUnstructured provides.
+	st := dv.Type()
+	data, err := json.Marshal(sv.Interface())
+	if err != nil {
+		return fmt.Errorf("error encoding %s to json: %v", st.String(), err)
+	}
+	if unmarshaler, ok := e.getJsonUnmarshaler(dv); ok {
+		return unmarshaler.UnmarshalJSON(data)
+	}
+	return fmt.Errorf("unable to unmarshal %v into %v", sv.Type(), dv.Type())
+}
+
+var (
+	nullBytes  = []byte("null")
+	trueBytes  = []byte("true")
+	falseBytes = []byte("false")
+)
+
+func (e TypeReflectCacheEntry) getJsonMarshaler(v reflect.Value) (json.Marshaler, bool) {
+	if e.isJsonMarshaler {
+		return v.Interface().(json.Marshaler), true
+	}
+	if e.ptrIsJsonMarshaler {
+		// Check pointer receivers if v is not a pointer
+		if v.Kind() != reflect.Ptr && v.CanAddr() {
+			v = v.Addr()
+			return v.Interface().(json.Marshaler), true
+		}
+	}
+	return nil, false
+}
+
+func (e TypeReflectCacheEntry) getJsonUnmarshaler(v reflect.Value) (json.Unmarshaler, bool) {
+	if !e.isJsonUnmarshaler {
+		return nil, false
+	}
+	return v.Addr().Interface().(json.Unmarshaler), true
+}
+
+func (e TypeReflectCacheEntry) getUnstructuredConverter(v reflect.Value) (UnstructuredConverter, bool) {
+	if e.isStringConvertable {
+		return v.Interface().(UnstructuredConverter), true
+	}
+	if e.ptrIsStringConvertable {
+		// Check pointer receivers if v is not a pointer
+		if v.CanAddr() {
+			v = v.Addr()
+			return v.Interface().(UnstructuredConverter), true
+		}
+	}
+	return nil, false
+}
+
+type typeReflectCache struct {
+	// use an atomic and copy-on-write since there are a fixed (typically very small) number of structs compiled into any
+	// go program using this cache
+	value atomic.Value
+	// mu is held by writers when performing load/modify/store operations on the cache, readers do not need to hold a
+	// read-lock since the atomic value is always read-only
+	mu sync.Mutex
+}
+
+func newReflectCache() *typeReflectCache {
+	cache := &typeReflectCache{}
+	cache.value.Store(make(reflectCacheMap))
+	return cache
+}
+
+type reflectCacheMap map[reflect.Type]*TypeReflectCacheEntry
+
+// get returns the reflectCacheMap.
+func (c *typeReflectCache) get() reflectCacheMap {
+	return c.value.Load().(reflectCacheMap)
+}
+
+// update merges the provided updates into the cache.
+func (c *typeReflectCache) update(updates reflectCacheMap) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	currentCacheMap := c.value.Load().(reflectCacheMap)
+
+	hasNewEntries := false
+	for t := range updates {
+		if _, ok := currentCacheMap[t]; !ok {
+			hasNewEntries = true
+			break
+		}
+	}
+	if !hasNewEntries {
+		// Bail if the updates have been set while waiting for lock acquisition.
+		// This is safe since setting entries is idempotent.
+		return
+	}
+
+	newCacheMap := make(reflectCacheMap, len(currentCacheMap)+len(updates))
+	for k, v := range currentCacheMap {
+		newCacheMap[k] = v
+	}
+	for t, update := range updates {
+		newCacheMap[t] = update
+	}
+	c.value.Store(newCacheMap)
+}
+
+// Below json Unmarshal is fromk8s.io/apimachinery/pkg/util/json
+// to handle number conversions as expected by Kubernetes
+
+// limit recursive depth to prevent stack overflow errors
+const maxDepth = 10000
+
+// unmarshal unmarshals the given data
+// If v is a *map[string]interface{}, numbers are converted to int64 or float64
+func unmarshal(data []byte, v interface{}) error {
+	switch v := v.(type) {
+	case *map[string]interface{}:
+		// Build a decoder from the given data
+		decoder := json.NewDecoder(bytes.NewBuffer(data))
+		// Preserve numbers, rather than casting to float64 automatically
+		decoder.UseNumber()
+		// Run the decode
+		if err := decoder.Decode(v); err != nil {
+			return err
+		}
+		// If the decode succeeds, post-process the map to convert json.Number objects to int64 or float64
+		return convertMapNumbers(*v, 0)
+
+	case *[]interface{}:
+		// Build a decoder from the given data
+		decoder := json.NewDecoder(bytes.NewBuffer(data))
+		// Preserve numbers, rather than casting to float64 automatically
+		decoder.UseNumber()
+		// Run the decode
+		if err := decoder.Decode(v); err != nil {
+			return err
+		}
+		// If the decode succeeds, post-process the map to convert json.Number objects to int64 or float64
+		return convertSliceNumbers(*v, 0)
+
+	default:
+		return json.Unmarshal(data, v)
+	}
+}
+
+// convertMapNumbers traverses the map, converting any json.Number values to int64 or float64.
+// values which are map[string]interface{} or []interface{} are recursively visited
+func convertMapNumbers(m map[string]interface{}, depth int) error {
+	if depth > maxDepth {
+		return fmt.Errorf("exceeded max depth of %d", maxDepth)
+	}
+
+	var err error
+	for k, v := range m {
+		switch v := v.(type) {
+		case json.Number:
+			m[k], err = convertNumber(v)
+		case map[string]interface{}:
+			err = convertMapNumbers(v, depth+1)
+		case []interface{}:
+			err = convertSliceNumbers(v, depth+1)
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// convertSliceNumbers traverses the slice, converting any json.Number values to int64 or float64.
+// values which are map[string]interface{} or []interface{} are recursively visited
+func convertSliceNumbers(s []interface{}, depth int) error {
+	if depth > maxDepth {
+		return fmt.Errorf("exceeded max depth of %d", maxDepth)
+	}
+
+	var err error
+	for i, v := range s {
+		switch v := v.(type) {
+		case json.Number:
+			s[i], err = convertNumber(v)
+		case map[string]interface{}:
+			err = convertMapNumbers(v, depth+1)
+		case []interface{}:
+			err = convertSliceNumbers(v, depth+1)
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// convertNumber converts a json.Number to an int64 or float64, or returns an error
+func convertNumber(n json.Number) (interface{}, error) {
+	// Attempt to convert to an int64 first
+	if i, err := n.Int64(); err == nil {
+		return i, nil
+	}
+	// Return a float64 (default json.Decode() behavior)
+	// An overflow will return an error
+	return n.Float64()
+}