k3s/vendor/k8s.io/apimachinery/pkg/util/strategicpatch/meta.go
Darren Shepherd fa08d6076c Update vendor
2019-01-11 21:58:27 -07:00

149 lines
4.3 KiB
Go

/*
Copyright 2017 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 strategicpatch
import (
"errors"
"fmt"
"reflect"
"k8s.io/apimachinery/pkg/util/mergepatch"
forkedjson "k8s.io/apimachinery/third_party/forked/golang/json"
)
type PatchMeta struct {
patchStrategies []string
patchMergeKey string
}
func (pm PatchMeta) GetPatchStrategies() []string {
if pm.patchStrategies == nil {
return []string{}
}
return pm.patchStrategies
}
func (pm PatchMeta) SetPatchStrategies(ps []string) {
pm.patchStrategies = ps
}
func (pm PatchMeta) GetPatchMergeKey() string {
return pm.patchMergeKey
}
func (pm PatchMeta) SetPatchMergeKey(pmk string) {
pm.patchMergeKey = pmk
}
type LookupPatchMeta interface {
// LookupPatchMetadataForStruct gets subschema and the patch metadata (e.g. patch strategy and merge key) for map.
LookupPatchMetadataForStruct(key string) (LookupPatchMeta, PatchMeta, error)
// LookupPatchMetadataForSlice get subschema and the patch metadata for slice.
LookupPatchMetadataForSlice(key string) (LookupPatchMeta, PatchMeta, error)
// Get the type name of the field
Name() string
}
type PatchMetaFromStruct struct {
T reflect.Type
}
func NewPatchMetaFromStruct(dataStruct interface{}) (PatchMetaFromStruct, error) {
t, err := getTagStructType(dataStruct)
return PatchMetaFromStruct{T: t}, err
}
var _ LookupPatchMeta = PatchMetaFromStruct{}
func (s PatchMetaFromStruct) LookupPatchMetadataForStruct(key string) (LookupPatchMeta, PatchMeta, error) {
fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadataForStruct(s.T, key)
if err != nil {
return nil, PatchMeta{}, err
}
return PatchMetaFromStruct{T: fieldType},
PatchMeta{
patchStrategies: fieldPatchStrategies,
patchMergeKey: fieldPatchMergeKey,
}, nil
}
func (s PatchMetaFromStruct) LookupPatchMetadataForSlice(key string) (LookupPatchMeta, PatchMeta, error) {
subschema, patchMeta, err := s.LookupPatchMetadataForStruct(key)
if err != nil {
return nil, PatchMeta{}, err
}
elemPatchMetaFromStruct := subschema.(PatchMetaFromStruct)
t := elemPatchMetaFromStruct.T
var elemType reflect.Type
switch t.Kind() {
// If t is an array or a slice, get the element type.
// If element is still an array or a slice, return an error.
// Otherwise, return element type.
case reflect.Array, reflect.Slice:
elemType = t.Elem()
if elemType.Kind() == reflect.Array || elemType.Kind() == reflect.Slice {
return nil, PatchMeta{}, errors.New("unexpected slice of slice")
}
// If t is an pointer, get the underlying element.
// If the underlying element is neither an array nor a slice, the pointer is pointing to a slice,
// e.g. https://github.com/kubernetes/kubernetes/blob/bc22e206c79282487ea0bf5696d5ccec7e839a76/staging/src/k8s.io/apimachinery/pkg/util/strategicpatch/patch_test.go#L2782-L2822
// If the underlying element is either an array or a slice, return its element type.
case reflect.Ptr:
t = t.Elem()
if t.Kind() == reflect.Array || t.Kind() == reflect.Slice {
t = t.Elem()
}
elemType = t
default:
return nil, PatchMeta{}, fmt.Errorf("expected slice or array type, but got: %s", s.T.Kind().String())
}
return PatchMetaFromStruct{T: elemType}, patchMeta, nil
}
func (s PatchMetaFromStruct) Name() string {
return s.T.Kind().String()
}
func getTagStructType(dataStruct interface{}) (reflect.Type, error) {
if dataStruct == nil {
return nil, mergepatch.ErrBadArgKind(struct{}{}, nil)
}
t := reflect.TypeOf(dataStruct)
// Get the underlying type for pointers
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() != reflect.Struct {
return nil, mergepatch.ErrBadArgKind(struct{}{}, dataStruct)
}
return t, nil
}
func GetTagStructTypeOrDie(dataStruct interface{}) reflect.Type {
t, err := getTagStructType(dataStruct)
if err != nil {
panic(err)
}
return t
}