diff --git a/staging/src/k8s.io/client-go/listers/generic_helpers.go b/staging/src/k8s.io/client-go/listers/generic_helpers.go new file mode 100644 index 00000000000..c69bb22b11e --- /dev/null +++ b/staging/src/k8s.io/client-go/listers/generic_helpers.go @@ -0,0 +1,72 @@ +/* +Copyright 2023 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 listers + +import ( + "k8s.io/apimachinery/pkg/api/errors" + "k8s.io/apimachinery/pkg/labels" + "k8s.io/apimachinery/pkg/runtime" + "k8s.io/apimachinery/pkg/runtime/schema" + "k8s.io/client-go/tools/cache" +) + +// ResourceIndexer wraps an indexer, resource, and optional namespace for a given type. +// This is intended for use by listers (generated by lister-gen) only. +type ResourceIndexer[T runtime.Object] struct { + indexer cache.Indexer + resource schema.GroupResource + namespace string // empty for non-namespaced types +} + +// New returns a new instance of a lister (resource indexer) wrapping the given indexer and resource for the specified type. +// This is intended for use by listers (generated by lister-gen) only. +func New[T runtime.Object](indexer cache.Indexer, resource schema.GroupResource) ResourceIndexer[T] { + return ResourceIndexer[T]{indexer: indexer, resource: resource} +} + +// NewNamespaced returns a new instance of a namespaced lister (resource indexer) wrapping the given parent and namespace for the specified type. +// This is intended for use by listers (generated by lister-gen) only. +func NewNamespaced[T runtime.Object](parent ResourceIndexer[T], namespace string) ResourceIndexer[T] { + return ResourceIndexer[T]{indexer: parent.indexer, resource: parent.resource, namespace: namespace} +} + +// List lists all resources in the indexer matching the given selector. +func (l ResourceIndexer[T]) List(selector labels.Selector) (ret []T, err error) { + // ListAllByNamespace reverts to ListAll on empty namespaces + err = cache.ListAllByNamespace(l.indexer, l.namespace, selector, func(m interface{}) { + ret = append(ret, m.(T)) + }) + return ret, err +} + +// Get retrieves the resource from the index for a given name. +func (l ResourceIndexer[T]) Get(name string) (T, error) { + var key string + if l.namespace == "" { + key = name + } else { + key = l.namespace + "/" + name + } + obj, exists, err := l.indexer.GetByKey(key) + if err != nil { + return *new(T), err + } + if !exists { + return *new(T), errors.NewNotFound(l.resource, name) + } + return obj.(T), nil +} diff --git a/staging/src/k8s.io/code-generator/cmd/lister-gen/generators/lister.go b/staging/src/k8s.io/code-generator/cmd/lister-gen/generators/lister.go index ce1f9eac713..8955e076f6c 100644 --- a/staging/src/k8s.io/code-generator/cmd/lister-gen/generators/lister.go +++ b/staging/src/k8s.io/code-generator/cmd/lister-gen/generators/lister.go @@ -215,6 +215,7 @@ func (g *listerGenerator) Imports(c *generator.Context) (imports []string) { imports = append(imports, g.imports.ImportLines()...) imports = append(imports, "k8s.io/apimachinery/pkg/api/errors") imports = append(imports, "k8s.io/apimachinery/pkg/labels") + imports = append(imports, "k8s.io/client-go/listers") // for Indexer imports = append(imports, "k8s.io/client-go/tools/cache") return @@ -243,18 +244,14 @@ func (g *listerGenerator) GenerateType(c *generator.Context, t *types.Type, w io sw.Do(typeListerStruct, m) sw.Do(typeListerConstructor, m) - sw.Do(typeListerList, m) if tags.NonNamespaced { - sw.Do(typeListerNonNamespacedGet, m) return sw.Error() } sw.Do(typeListerNamespaceLister, m) sw.Do(namespaceListerInterface, m) sw.Do(namespaceListerStruct, m) - sw.Do(namespaceListerList, m) - sw.Do(namespaceListerGet, m) return sw.Error() } @@ -286,48 +283,27 @@ type $.type|public$Lister interface { } ` +// This embeds a typed resource indexer instead of aliasing, so that the struct +// is available as a receiver for methods specific to the generated type +// (from the corresponding expansion interface). var typeListerStruct = ` // $.type|private$Lister implements the $.type|public$Lister interface. type $.type|private$Lister struct { - indexer cache.Indexer + listers.ResourceIndexer[*$.type|raw$] } ` var typeListerConstructor = ` // New$.type|public$Lister returns a new $.type|public$Lister. func New$.type|public$Lister(indexer cache.Indexer) $.type|public$Lister { - return &$.type|private$Lister{indexer: indexer} -} -` - -var typeListerList = ` -// List lists all $.type|publicPlural$ in the indexer. -func (s *$.type|private$Lister) List(selector labels.Selector) (ret []*$.type|raw$, err error) { - err = cache.ListAll(s.indexer, selector, func(m interface{}) { - ret = append(ret, m.(*$.type|raw$)) - }) - return ret, err + return &$.type|private$Lister{listers.New[*$.type|raw$](indexer, $.Resource|raw$("$.type|lowercaseSingular$"))} } ` var typeListerNamespaceLister = ` // $.type|publicPlural$ returns an object that can list and get $.type|publicPlural$. func (s *$.type|private$Lister) $.type|publicPlural$(namespace string) $.type|public$NamespaceLister { - return $.type|private$NamespaceLister{indexer: s.indexer, namespace: namespace} -} -` - -var typeListerNonNamespacedGet = ` -// Get retrieves the $.type|public$ from the index for a given name. -func (s *$.type|private$Lister) Get(name string) (*$.type|raw$, error) { - obj, exists, err := s.indexer.GetByKey(name) - if err != nil { - return nil, err - } - if !exists { - return nil, errors.NewNotFound($.Resource|raw$("$.type|lowercaseSingular$"), name) - } - return obj.(*$.type|raw$), nil + return $.type|private$NamespaceLister{listers.NewNamespaced[*$.type|raw$](s.ResourceIndexer, namespace)} } ` @@ -345,35 +321,13 @@ type $.type|public$NamespaceLister interface { } ` +// This embeds a typed namespaced resource indexer instead of aliasing, so that the struct +// is available as a receiver for methods specific to the generated type +// (from the corresponding expansion interface). var namespaceListerStruct = ` // $.type|private$NamespaceLister implements the $.type|public$NamespaceLister // interface. type $.type|private$NamespaceLister struct { - indexer cache.Indexer - namespace string -} -` - -var namespaceListerList = ` -// List lists all $.type|publicPlural$ in the indexer for a given namespace. -func (s $.type|private$NamespaceLister) List(selector labels.Selector) (ret []*$.type|raw$, err error) { - err = cache.ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) { - ret = append(ret, m.(*$.type|raw$)) - }) - return ret, err -} -` - -var namespaceListerGet = ` -// Get retrieves the $.type|public$ from the indexer for a given namespace and name. -func (s $.type|private$NamespaceLister) Get(name string) (*$.type|raw$, error) { - obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name) - if err != nil { - return nil, err - } - if !exists { - return nil, errors.NewNotFound($.Resource|raw$("$.type|lowercaseSingular$"), name) - } - return obj.(*$.type|raw$), nil + listers.ResourceIndexer[*$.type|raw$] } `