knative.dev/pkg@v0.0.0-20260602142205-ac97e43f6622/apis/duck/enqueue.go (about)

     1  /*
     2  Copyright 2018 The Knative Authors
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package duck
    18  
    19  import (
    20  	"context"
    21  
    22  	"k8s.io/apimachinery/pkg/runtime/schema"
    23  	"k8s.io/client-go/tools/cache"
    24  )
    25  
    26  // EnqueueInformerFactory implements InformerFactory by delegating to another
    27  // InformerFactory, but attaching a ResourceEventHandler to the informer.
    28  type EnqueueInformerFactory struct {
    29  	Delegate InformerFactory
    30  
    31  	EventHandler cache.ResourceEventHandler
    32  }
    33  
    34  // Check that EnqueueInformerFactory implements InformerFactory.
    35  var _ InformerFactory = (*EnqueueInformerFactory)(nil)
    36  
    37  // Get implements InformerFactory.
    38  func (cif *EnqueueInformerFactory) Get(ctx context.Context, gvr schema.GroupVersionResource) (cache.SharedIndexInformer, cache.GenericLister, error) {
    39  	inf, lister, err := cif.Delegate.Get(ctx, gvr)
    40  	if err != nil {
    41  		return nil, nil, err
    42  	}
    43  	// If there is an informer, attach our event handler.
    44  	inf.AddEventHandler(cif.EventHandler)
    45  	return inf, lister, nil
    46  }