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author | OpenShift Merge Robot <openshift-merge-robot@users.noreply.github.com> | 2020-05-08 12:59:42 +0200 |
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committer | GitHub <noreply@github.com> | 2020-05-08 12:59:42 +0200 |
commit | 4b300a12cedabff3c57ee657afac0696cefaae0a (patch) | |
tree | 61c5fceec50e88338038415fa1375371bef2dca4 /vendor/sigs.k8s.io/structured-merge-diff/v3/value/reflectcache.go | |
parent | 70e7fc670be13d3877e65e160456c312e23a5806 (diff) | |
parent | 2f0bc5ff1cde9afb595868b92dd123478af9ef74 (diff) | |
download | podman-4b300a12cedabff3c57ee657afac0696cefaae0a.tar.gz podman-4b300a12cedabff3c57ee657afac0696cefaae0a.tar.bz2 podman-4b300a12cedabff3c57ee657afac0696cefaae0a.zip |
Merge pull request #6086 from containers/dependabot/go_modules/k8s.io/api-0.18.2
Bump k8s.io/api from 0.17.4 to 0.18.2
Diffstat (limited to 'vendor/sigs.k8s.io/structured-merge-diff/v3/value/reflectcache.go')
-rw-r--r-- | vendor/sigs.k8s.io/structured-merge-diff/v3/value/reflectcache.go | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/vendor/sigs.k8s.io/structured-merge-diff/v3/value/reflectcache.go b/vendor/sigs.k8s.io/structured-merge-diff/v3/value/reflectcache.go new file mode 100644 index 000000000..49e6dd169 --- /dev/null +++ b/vendor/sigs.k8s.io/structured-merge-diff/v3/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() +} |