You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: store.go
    path of file: ./repos/kubernetes/staging/src/k8s.io/apiserver/pkg/registry/generic/registry
    
    the code of the file until where you have to start completion: /*
Copyright 2014 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 registry

import (
	"context"
	"fmt"
	"strings"
	"sync"
	"time"

	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apimachinery/pkg/api/validation"
	"k8s.io/apimachinery/pkg/api/validation/path"
	metainternalversion "k8s.io/apimachinery/pkg/apis/meta/internalversion"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/util/validation/field"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
	"k8s.io/apiserver/pkg/features"
	"k8s.io/apiserver/pkg/registry/generic"
	"k8s.io/apiserver/pkg/registry/rest"
	"k8s.io/apiserver/pkg/storage"
	storeerr "k8s.io/apiserver/pkg/storage/errors"
	"k8s.io/apiserver/pkg/storage/etcd3/metrics"
	"k8s.io/apiserver/pkg/util/dryrun"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	flowcontrolrequest "k8s.io/apiserver/pkg/util/flowcontrol/request"
	"k8s.io/client-go/tools/cache"

	"k8s.io/klog/v2"
)

// FinishFunc is a function returned by Begin hooks to complete an operation.
type FinishFunc func(ctx context.Context, success bool)

// AfterDeleteFunc is the type used for the Store.AfterDelete hook.
type AfterDeleteFunc func(obj runtime.Object, options *metav1.DeleteOptions)

// BeginCreateFunc is the type used for the Store.BeginCreate hook.
type BeginCreateFunc func(ctx context.Context, obj runtime.Object, options *metav1.CreateOptions) (FinishFunc, error)

// AfterCreateFunc is the type used for the Store.AfterCreate hook.
type AfterCreateFunc func(obj runtime.Object, options *metav1.CreateOptions)

// BeginUpdateFunc is the type used for the Store.BeginUpdate hook.
type BeginUpdateFunc func(ctx context.Context, obj, old runtime.Object, options *metav1.UpdateOptions) (FinishFunc, error)

// AfterUpdateFunc is the type used for the Store.AfterUpdate hook.
type AfterUpdateFunc func(obj runtime.Object, options *metav1.UpdateOptions)

// GenericStore interface can be used for type assertions when we need to access the underlying strategies.
type GenericStore interface {
	GetCreateStrategy() rest.RESTCreateStrategy
	GetUpdateStrategy() rest.RESTUpdateStrategy
	GetDeleteStrategy() rest.RESTDeleteStrategy
}

// Store implements k8s.io/apiserver/pkg/registry/rest.StandardStorage. It's
// intended to be embeddable and
    
func (e *Store) DeleteCollection(ctx context.Context, deleteValidation rest.ValidateObjectFunc, options *metav1.DeleteOptions, listOptions *metainternalversion.ListOptions) (runtime.Object, error) {
	if listOptions == nil {
		listOptions = &metainternalversion.ListOptions{}
	} else {
		listOptions = listOptions.DeepCopy()
	}

	var items []runtime.Object

	// TODO(wojtek-t): Decide if we don't want to start workers more opportunistically.
	workersNumber := e.DeleteCollectionWorkers
	if workersNumber < 1 {
		workersNumber = 1
	}
	wg := sync.WaitGroup{}
	// Ensure that chanSize is not too high (to avoid wasted work) but
	// at the same time high enough to start listing before we process
	// the whole page.
	chanSize := 2 * workersNumber
	if chanSize < 256 {
		chanSize = 256
	}
	toProcess := make(chan runtime.Object, chanSize)
	errs := make(chan error, workersNumber+1)
	workersExited := make(chan struct{})

	wg.Add(workersNumber)
	for i := 0; i < workersNumber; i++ {
		go func() {
			// panics don't cross goroutine boundaries
			defer utilruntime.HandleCrash(func(panicReason interface{}) {
				errs <- fmt.Errorf("DeleteCollection goroutine panicked: %v", panicReason)
			})
			defer wg.Done()

			for item := range toProcess {
				accessor, err := meta.Accessor(item)
				if err != nil {
					errs <- err
					return
				}
				// DeepCopy the deletion options because individual graceful deleters communicate changes via a mutating
				// function in the delete strategy called in the delete method.  While that is always ugly, it works
				// when making a single call.  When making multiple calls via delete collection, the mutation applied to
				// pod/A can change the option ultimately used for pod/B.
				if _, _, err := e.Delete(ctx, accessor.GetName(), deleteValidation, options.DeepCopy()); err != nil && !apierrors.IsNotFound(err) {
					klog.V(4).InfoS("Delete object in DeleteCollection failed", "object", klog.KObj(accessor), "err", err)
					errs <- err
					return
				}
			}
		}()
	}
	// In case of all workers exit, notify distributor.
	go func() {
		defer utilruntime.HandleCrash(func(panicReason interface{}) {
			errs <- fmt.Errorf("DeleteCollection workers closer panicked: %v", panicReason)
		})
		wg.Wait()
		close(workersExited)
	}()

	hasLimit := listOptions.Limit > 0
	if listOptions.Limit == 0 {
		listOptions.Limit = deleteCollectionPageSize
	}

	// Paginate the list request and throw all items into workers.
	listObj, err := func() (runtime.Object, error) {
		defer close(toProcess)

		processedItems := 0
		var originalList runtime.Object
		for {
			select {
			case <-ctx.Done():
				return nil, ctx.Err()
			default:
			}

			listObj, err := e.List(ctx, listOptions)
			if err != nil {
				return nil, err
			}

			newItems, err := meta.ExtractList(listObj)
			if err != nil {
				return nil, err
			}
			items = append(items, newItems...)

			for i := 0; i < len(newItems); i++ {
				select {
				case toProcess <- newItems[i]:
				case <-workersExited:
					klog.V(4).InfoS("workers already exited, and there are some items waiting to be processed", "queued/finished", i, "total", processedItems+len(newItems))
					// Try to propagate an error from the workers if possible.
					select {
					case err := <-errs:
						return nil, err
					default:
						return nil, fmt.Errorf("all DeleteCollection workers exited")
					}
				}
			}
			processedItems += len(newItems)

			// If the original request was setting the limit, finish after running it.
			if hasLimit {
				return listObj, nil
			}

			if originalList == nil {
				originalList = listObj
				meta.SetList(originalList, nil)
			}

			// If there are no more items, return the list.
			m, err := meta.ListAccessor(listObj)
			if err != nil {
				return nil, err
			}
			if len(m.GetContinue()) == 0 {
				meta.SetList(originalList, items)
				return originalList, nil
			}

			// Set up the next loop.
			listOptions.Continue = m.GetContinue()
			listOptions.ResourceVersion = ""
			listOptions.ResourceVersionMatch = ""
		}
	}()
	if err != nil {
		return nil, err
	}

	// Wait for all workers to exit.
	<-workersExited

	select {
	case err := <-errs:
		return nil, err
	default:
		return listObj, nil
	}
}