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105 lines
3 KiB
Go
105 lines
3 KiB
Go
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/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package meta
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import (
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"sync"
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"k8s.io/apimachinery/pkg/runtime/schema"
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)
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// lazyObject defers loading the mapper and typer until necessary.
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type lazyObject struct {
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loader func() (RESTMapper, error)
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lock sync.Mutex
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loaded bool
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err error
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mapper RESTMapper
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}
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// NewLazyObjectLoader handles unrecoverable errors when creating a RESTMapper / ObjectTyper by
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// returning those initialization errors when the interface methods are invoked. This defers the
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// initialization and any server calls until a client actually needs to perform the action.
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func NewLazyRESTMapperLoader(fn func() (RESTMapper, error)) RESTMapper {
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obj := &lazyObject{loader: fn}
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return obj
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}
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// init lazily loads the mapper and typer, returning an error if initialization has failed.
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func (o *lazyObject) init() error {
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o.lock.Lock()
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defer o.lock.Unlock()
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if o.loaded {
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return o.err
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}
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o.mapper, o.err = o.loader()
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o.loaded = true
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return o.err
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}
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var _ RESTMapper = &lazyObject{}
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func (o *lazyObject) KindFor(resource schema.GroupVersionResource) (schema.GroupVersionKind, error) {
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if err := o.init(); err != nil {
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return schema.GroupVersionKind{}, err
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}
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return o.mapper.KindFor(resource)
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}
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func (o *lazyObject) KindsFor(resource schema.GroupVersionResource) ([]schema.GroupVersionKind, error) {
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if err := o.init(); err != nil {
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return []schema.GroupVersionKind{}, err
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}
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return o.mapper.KindsFor(resource)
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}
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func (o *lazyObject) ResourceFor(input schema.GroupVersionResource) (schema.GroupVersionResource, error) {
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if err := o.init(); err != nil {
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return schema.GroupVersionResource{}, err
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}
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return o.mapper.ResourceFor(input)
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}
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func (o *lazyObject) ResourcesFor(input schema.GroupVersionResource) ([]schema.GroupVersionResource, error) {
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if err := o.init(); err != nil {
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return []schema.GroupVersionResource{}, err
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}
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return o.mapper.ResourcesFor(input)
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}
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func (o *lazyObject) RESTMapping(gk schema.GroupKind, versions ...string) (*RESTMapping, error) {
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if err := o.init(); err != nil {
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return nil, err
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}
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return o.mapper.RESTMapping(gk, versions...)
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}
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func (o *lazyObject) RESTMappings(gk schema.GroupKind, versions ...string) ([]*RESTMapping, error) {
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if err := o.init(); err != nil {
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return nil, err
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}
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return o.mapper.RESTMappings(gk, versions...)
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}
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func (o *lazyObject) ResourceSingularizer(resource string) (singular string, err error) {
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if err := o.init(); err != nil {
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return "", err
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}
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return o.mapper.ResourceSingularizer(resource)
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}
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