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-rw-r--r--vendor/sigs.k8s.io/structured-merge-diff/v4/value/reflectcache.go463
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
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+++ 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()
+}