diff options
Diffstat (limited to 'vendor/sigs.k8s.io/structured-merge-diff/v4/value/structreflect.go')
-rw-r--r-- | vendor/sigs.k8s.io/structured-merge-diff/v4/value/structreflect.go | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/vendor/sigs.k8s.io/structured-merge-diff/v4/value/structreflect.go b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/structreflect.go new file mode 100644 index 000000000..4a7bb5c6e --- /dev/null +++ b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/structreflect.go @@ -0,0 +1,208 @@ +/* +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 value + +import ( + "fmt" + "reflect" +) + +type structReflect struct { + valueReflect +} + +func (r structReflect) Length() int { + i := 0 + eachStructField(r.Value, func(_ *TypeReflectCacheEntry, s string, value reflect.Value) bool { + i++ + return true + }) + return i +} + +func (r structReflect) Empty() bool { + return eachStructField(r.Value, func(_ *TypeReflectCacheEntry, s string, value reflect.Value) bool { + return false // exit early if the struct is non-empty + }) +} + +func (r structReflect) Get(key string) (Value, bool) { + return r.GetUsing(HeapAllocator, key) +} + +func (r structReflect) GetUsing(a Allocator, key string) (Value, bool) { + if val, ok := r.findJsonNameField(key); ok { + return a.allocValueReflect().mustReuse(val, nil, nil, nil), true + } + return nil, false +} + +func (r structReflect) Has(key string) bool { + _, ok := r.findJsonNameField(key) + return ok +} + +func (r structReflect) Set(key string, val Value) { + fieldEntry, ok := TypeReflectEntryOf(r.Value.Type()).Fields()[key] + if !ok { + panic(fmt.Sprintf("key %s may not be set on struct %T: field does not exist", key, r.Value.Interface())) + } + oldVal := fieldEntry.GetFrom(r.Value) + newVal := reflect.ValueOf(val.Unstructured()) + r.update(fieldEntry, key, oldVal, newVal) +} + +func (r structReflect) Delete(key string) { + fieldEntry, ok := TypeReflectEntryOf(r.Value.Type()).Fields()[key] + if !ok { + panic(fmt.Sprintf("key %s may not be deleted on struct %T: field does not exist", key, r.Value.Interface())) + } + oldVal := fieldEntry.GetFrom(r.Value) + if oldVal.Kind() != reflect.Ptr && !fieldEntry.isOmitEmpty { + panic(fmt.Sprintf("key %s may not be deleted on struct: %T: value is neither a pointer nor an omitempty field", key, r.Value.Interface())) + } + r.update(fieldEntry, key, oldVal, reflect.Zero(oldVal.Type())) +} + +func (r structReflect) update(fieldEntry *FieldCacheEntry, key string, oldVal, newVal reflect.Value) { + if oldVal.CanSet() { + oldVal.Set(newVal) + return + } + + // map items are not addressable, so if a struct is contained in a map, the only way to modify it is + // to write a replacement fieldEntry into the map. + if r.ParentMap != nil { + if r.ParentMapKey == nil { + panic("ParentMapKey must not be nil if ParentMap is not nil") + } + replacement := reflect.New(r.Value.Type()).Elem() + fieldEntry.GetFrom(replacement).Set(newVal) + r.ParentMap.SetMapIndex(*r.ParentMapKey, replacement) + return + } + + // This should never happen since NewValueReflect ensures that the root object reflected on is a pointer and map + // item replacement is handled above. + panic(fmt.Sprintf("key %s may not be modified on struct: %T: struct is not settable", key, r.Value.Interface())) +} + +func (r structReflect) Iterate(fn func(string, Value) bool) bool { + return r.IterateUsing(HeapAllocator, fn) +} + +func (r structReflect) IterateUsing(a Allocator, fn func(string, Value) bool) bool { + vr := a.allocValueReflect() + defer a.Free(vr) + return eachStructField(r.Value, func(e *TypeReflectCacheEntry, s string, value reflect.Value) bool { + return fn(s, vr.mustReuse(value, e, nil, nil)) + }) +} + +func eachStructField(structVal reflect.Value, fn func(*TypeReflectCacheEntry, string, reflect.Value) bool) bool { + for _, fieldCacheEntry := range TypeReflectEntryOf(structVal.Type()).OrderedFields() { + fieldVal := fieldCacheEntry.GetFrom(structVal) + if fieldCacheEntry.CanOmit(fieldVal) { + // omit it + continue + } + ok := fn(fieldCacheEntry.TypeEntry, fieldCacheEntry.JsonName, fieldVal) + if !ok { + return false + } + } + return true +} + +func (r structReflect) Unstructured() interface{} { + // Use number of struct fields as a cheap way to rough estimate map size + result := make(map[string]interface{}, r.Value.NumField()) + r.Iterate(func(s string, value Value) bool { + result[s] = value.Unstructured() + return true + }) + return result +} + +func (r structReflect) Equals(m Map) bool { + return r.EqualsUsing(HeapAllocator, m) +} + +func (r structReflect) EqualsUsing(a Allocator, m Map) bool { + // MapEquals uses zip and is fairly efficient for structReflect + return MapEqualsUsing(a, &r, m) +} + +func (r structReflect) findJsonNameFieldAndNotEmpty(jsonName string) (reflect.Value, bool) { + structCacheEntry, ok := TypeReflectEntryOf(r.Value.Type()).Fields()[jsonName] + if !ok { + return reflect.Value{}, false + } + fieldVal := structCacheEntry.GetFrom(r.Value) + return fieldVal, !structCacheEntry.CanOmit(fieldVal) +} + +func (r structReflect) findJsonNameField(jsonName string) (val reflect.Value, ok bool) { + structCacheEntry, ok := TypeReflectEntryOf(r.Value.Type()).Fields()[jsonName] + if !ok { + return reflect.Value{}, false + } + fieldVal := structCacheEntry.GetFrom(r.Value) + return fieldVal, !structCacheEntry.CanOmit(fieldVal) +} + +func (r structReflect) Zip(other Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool { + return r.ZipUsing(HeapAllocator, other, order, fn) +} + +func (r structReflect) ZipUsing(a Allocator, other Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool { + if otherStruct, ok := other.(*structReflect); ok && r.Value.Type() == otherStruct.Value.Type() { + lhsvr, rhsvr := a.allocValueReflect(), a.allocValueReflect() + defer a.Free(lhsvr) + defer a.Free(rhsvr) + return r.structZip(otherStruct, lhsvr, rhsvr, fn) + } + return defaultMapZip(a, &r, other, order, fn) +} + +// structZip provides an optimized zip for structReflect types. The zip is always lexical key ordered since there is +// no additional cost to ordering the zip for structured types. +func (r structReflect) structZip(other *structReflect, lhsvr, rhsvr *valueReflect, fn func(key string, lhs, rhs Value) bool) bool { + lhsVal := r.Value + rhsVal := other.Value + + for _, fieldCacheEntry := range TypeReflectEntryOf(lhsVal.Type()).OrderedFields() { + lhsFieldVal := fieldCacheEntry.GetFrom(lhsVal) + rhsFieldVal := fieldCacheEntry.GetFrom(rhsVal) + lhsOmit := fieldCacheEntry.CanOmit(lhsFieldVal) + rhsOmit := fieldCacheEntry.CanOmit(rhsFieldVal) + if lhsOmit && rhsOmit { + continue + } + var lhsVal, rhsVal Value + if !lhsOmit { + lhsVal = lhsvr.mustReuse(lhsFieldVal, fieldCacheEntry.TypeEntry, nil, nil) + } + if !rhsOmit { + rhsVal = rhsvr.mustReuse(rhsFieldVal, fieldCacheEntry.TypeEntry, nil, nil) + } + if !fn(fieldCacheEntry.JsonName, lhsVal, rhsVal) { + return false + } + } + return true +} |