Add vendor dependencies as part git repo

vendor/k8s.io/client-go/tools/cache/OWNERS

@@ -0,0 +1,28 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+approvers:
+  - thockin
+  - lavalamp
+  - smarterclayton
+  - wojtek-t
+  - deads2k
+  - caesarxuchao
+  - liggitt
+  - ncdc
+reviewers:
+  - thockin
+  - lavalamp
+  - smarterclayton
+  - wojtek-t
+  - deads2k
+  - derekwaynecarr
+  - caesarxuchao
+  - mikedanese
+  - liggitt
+  - janetkuo
+  - justinsb
+  - soltysh
+  - jsafrane
+  - dims
+  - ingvagabund
+  - ncdc

vendor/k8s.io/client-go/tools/cache/controller.go

@@ -0,0 +1,498 @@
+/*
+Copyright 2015 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 cache
+
+import (
+	"errors"
+	"sync"
+	"time"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/utils/clock"
+)
+
+// This file implements a low-level controller that is used in
+// sharedIndexInformer, which is an implementation of
+// SharedIndexInformer.  Such informers, in turn, are key components
+// in the high level controllers that form the backbone of the
+// Kubernetes control plane.  Look at those for examples, or the
+// example in
+// https://github.com/kubernetes/client-go/tree/master/examples/workqueue
+// .
+
+// Config contains all the settings for one of these low-level controllers.
+type Config struct {
+	// The queue for your objects - has to be a DeltaFIFO due to
+	// assumptions in the implementation. Your Process() function
+	// should accept the output of this Queue's Pop() method.
+	Queue
+
+	// Something that can list and watch your objects.
+	ListerWatcher
+
+	// Something that can process a popped Deltas.
+	Process ProcessFunc
+
+	// ObjectType is an example object of the type this controller is
+	// expected to handle.  Only the type needs to be right, except
+	// that when that is `unstructured.Unstructured` the object's
+	// `"apiVersion"` and `"kind"` must also be right.
+	ObjectType runtime.Object
+
+	// FullResyncPeriod is the period at which ShouldResync is considered.
+	FullResyncPeriod time.Duration
+
+	// ShouldResync is periodically used by the reflector to determine
+	// whether to Resync the Queue. If ShouldResync is `nil` or
+	// returns true, it means the reflector should proceed with the
+	// resync.
+	ShouldResync ShouldResyncFunc
+
+	// If true, when Process() returns an error, re-enqueue the object.
+	// TODO: add interface to let you inject a delay/backoff or drop
+	//       the object completely if desired. Pass the object in
+	//       question to this interface as a parameter.  This is probably moot
+	//       now that this functionality appears at a higher level.
+	RetryOnError bool
+
+	// Called whenever the ListAndWatch drops the connection with an error.
+	WatchErrorHandler WatchErrorHandler
+
+	// WatchListPageSize is the requested chunk size of initial and relist watch lists.
+	WatchListPageSize int64
+}
+
+// ShouldResyncFunc is a type of function that indicates if a reflector should perform a
+// resync or not. It can be used by a shared informer to support multiple event handlers with custom
+// resync periods.
+type ShouldResyncFunc func() bool
+
+// ProcessFunc processes a single object.
+type ProcessFunc func(obj interface{}) error
+
+// `*controller` implements Controller
+type controller struct {
+	config         Config
+	reflector      *Reflector
+	reflectorMutex sync.RWMutex
+	clock          clock.Clock
+}
+
+// Controller is a low-level controller that is parameterized by a
+// Config and used in sharedIndexInformer.
+type Controller interface {
+	// Run does two things.  One is to construct and run a Reflector
+	// to pump objects/notifications from the Config's ListerWatcher
+	// to the Config's Queue and possibly invoke the occasional Resync
+	// on that Queue.  The other is to repeatedly Pop from the Queue
+	// and process with the Config's ProcessFunc.  Both of these
+	// continue until `stopCh` is closed.
+	Run(stopCh <-chan struct{})
+
+	// HasSynced delegates to the Config's Queue
+	HasSynced() bool
+
+	// LastSyncResourceVersion delegates to the Reflector when there
+	// is one, otherwise returns the empty string
+	LastSyncResourceVersion() string
+}
+
+// New makes a new Controller from the given Config.
+func New(c *Config) Controller {
+	ctlr := &controller{
+		config: *c,
+		clock:  &clock.RealClock{},
+	}
+	return ctlr
+}
+
+// Run begins processing items, and will continue until a value is sent down stopCh or it is closed.
+// It's an error to call Run more than once.
+// Run blocks; call via go.
+func (c *controller) Run(stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+	go func() {
+		<-stopCh
+		c.config.Queue.Close()
+	}()
+	r := NewReflector(
+		c.config.ListerWatcher,
+		c.config.ObjectType,
+		c.config.Queue,
+		c.config.FullResyncPeriod,
+	)
+	r.ShouldResync = c.config.ShouldResync
+	r.WatchListPageSize = c.config.WatchListPageSize
+	r.clock = c.clock
+	if c.config.WatchErrorHandler != nil {
+		r.watchErrorHandler = c.config.WatchErrorHandler
+	}
+
+	c.reflectorMutex.Lock()
+	c.reflector = r
+	c.reflectorMutex.Unlock()
+
+	var wg wait.Group
+
+	wg.StartWithChannel(stopCh, r.Run)
+
+	wait.Until(c.processLoop, time.Second, stopCh)
+	wg.Wait()
+}
+
+// Returns true once this controller has completed an initial resource listing
+func (c *controller) HasSynced() bool {
+	return c.config.Queue.HasSynced()
+}
+
+func (c *controller) LastSyncResourceVersion() string {
+	c.reflectorMutex.RLock()
+	defer c.reflectorMutex.RUnlock()
+	if c.reflector == nil {
+		return ""
+	}
+	return c.reflector.LastSyncResourceVersion()
+}
+
+// processLoop drains the work queue.
+// TODO: Consider doing the processing in parallel. This will require a little thought
+// to make sure that we don't end up processing the same object multiple times
+// concurrently.
+//
+// TODO: Plumb through the stopCh here (and down to the queue) so that this can
+// actually exit when the controller is stopped. Or just give up on this stuff
+// ever being stoppable. Converting this whole package to use Context would
+// also be helpful.
+func (c *controller) processLoop() {
+	for {
+		obj, err := c.config.Queue.Pop(PopProcessFunc(c.config.Process))
+		if err != nil {
+			if err == ErrFIFOClosed {
+				return
+			}
+			if c.config.RetryOnError {
+				// This is the safe way to re-enqueue.
+				c.config.Queue.AddIfNotPresent(obj)
+			}
+		}
+	}
+}
+
+// ResourceEventHandler can handle notifications for events that
+// happen to a resource. The events are informational only, so you
+// can't return an error.  The handlers MUST NOT modify the objects
+// received; this concerns not only the top level of structure but all
+// the data structures reachable from it.
+//  * OnAdd is called when an object is added.
+//  * OnUpdate is called when an object is modified. Note that oldObj is the
+//      last known state of the object-- it is possible that several changes
+//      were combined together, so you can't use this to see every single
+//      change. OnUpdate is also called when a re-list happens, and it will
+//      get called even if nothing changed. This is useful for periodically
+//      evaluating or syncing something.
+//  * OnDelete will get the final state of the item if it is known, otherwise
+//      it will get an object of type DeletedFinalStateUnknown. This can
+//      happen if the watch is closed and misses the delete event and we don't
+//      notice the deletion until the subsequent re-list.
+type ResourceEventHandler interface {
+	OnAdd(obj interface{})
+	OnUpdate(oldObj, newObj interface{})
+	OnDelete(obj interface{})
+}
+
+// ResourceEventHandlerFuncs is an adaptor to let you easily specify as many or
+// as few of the notification functions as you want while still implementing
+// ResourceEventHandler.  This adapter does not remove the prohibition against
+// modifying the objects.
+type ResourceEventHandlerFuncs struct {
+	AddFunc    func(obj interface{})
+	UpdateFunc func(oldObj, newObj interface{})
+	DeleteFunc func(obj interface{})
+}
+
+// OnAdd calls AddFunc if it's not nil.
+func (r ResourceEventHandlerFuncs) OnAdd(obj interface{}) {
+	if r.AddFunc != nil {
+		r.AddFunc(obj)
+	}
+}
+
+// OnUpdate calls UpdateFunc if it's not nil.
+func (r ResourceEventHandlerFuncs) OnUpdate(oldObj, newObj interface{}) {
+	if r.UpdateFunc != nil {
+		r.UpdateFunc(oldObj, newObj)
+	}
+}
+
+// OnDelete calls DeleteFunc if it's not nil.
+func (r ResourceEventHandlerFuncs) OnDelete(obj interface{}) {
+	if r.DeleteFunc != nil {
+		r.DeleteFunc(obj)
+	}
+}
+
+// FilteringResourceEventHandler applies the provided filter to all events coming
+// in, ensuring the appropriate nested handler method is invoked. An object
+// that starts passing the filter after an update is considered an add, and an
+// object that stops passing the filter after an update is considered a delete.
+// Like the handlers, the filter MUST NOT modify the objects it is given.
+type FilteringResourceEventHandler struct {
+	FilterFunc func(obj interface{}) bool
+	Handler    ResourceEventHandler
+}
+
+// OnAdd calls the nested handler only if the filter succeeds
+func (r FilteringResourceEventHandler) OnAdd(obj interface{}) {
+	if !r.FilterFunc(obj) {
+		return
+	}
+	r.Handler.OnAdd(obj)
+}
+
+// OnUpdate ensures the proper handler is called depending on whether the filter matches
+func (r FilteringResourceEventHandler) OnUpdate(oldObj, newObj interface{}) {
+	newer := r.FilterFunc(newObj)
+	older := r.FilterFunc(oldObj)
+	switch {
+	case newer && older:
+		r.Handler.OnUpdate(oldObj, newObj)
+	case newer && !older:
+		r.Handler.OnAdd(newObj)
+	case !newer && older:
+		r.Handler.OnDelete(oldObj)
+	default:
+		// do nothing
+	}
+}
+
+// OnDelete calls the nested handler only if the filter succeeds
+func (r FilteringResourceEventHandler) OnDelete(obj interface{}) {
+	if !r.FilterFunc(obj) {
+		return
+	}
+	r.Handler.OnDelete(obj)
+}
+
+// DeletionHandlingMetaNamespaceKeyFunc checks for
+// DeletedFinalStateUnknown objects before calling
+// MetaNamespaceKeyFunc.
+func DeletionHandlingMetaNamespaceKeyFunc(obj interface{}) (string, error) {
+	if d, ok := obj.(DeletedFinalStateUnknown); ok {
+		return d.Key, nil
+	}
+	return MetaNamespaceKeyFunc(obj)
+}
+
+// NewInformer returns a Store and a controller for populating the store
+// while also providing event notifications. You should only used the returned
+// Store for Get/List operations; Add/Modify/Deletes will cause the event
+// notifications to be faulty.
+//
+// Parameters:
+//  * lw is list and watch functions for the source of the resource you want to
+//    be informed of.
+//  * objType is an object of the type that you expect to receive.
+//  * resyncPeriod: if non-zero, will re-list this often (you will get OnUpdate
+//    calls, even if nothing changed). Otherwise, re-list will be delayed as
+//    long as possible (until the upstream source closes the watch or times out,
+//    or you stop the controller).
+//  * h is the object you want notifications sent to.
+//
+func NewInformer(
+	lw ListerWatcher,
+	objType runtime.Object,
+	resyncPeriod time.Duration,
+	h ResourceEventHandler,
+) (Store, Controller) {
+	// This will hold the client state, as we know it.
+	clientState := NewStore(DeletionHandlingMetaNamespaceKeyFunc)
+
+	return clientState, newInformer(lw, objType, resyncPeriod, h, clientState, nil)
+}
+
+// NewIndexerInformer returns an Indexer and a Controller for populating the index
+// while also providing event notifications. You should only used the returned
+// Index for Get/List operations; Add/Modify/Deletes will cause the event
+// notifications to be faulty.
+//
+// Parameters:
+//  * lw is list and watch functions for the source of the resource you want to
+//    be informed of.
+//  * objType is an object of the type that you expect to receive.
+//  * resyncPeriod: if non-zero, will re-list this often (you will get OnUpdate
+//    calls, even if nothing changed). Otherwise, re-list will be delayed as
+//    long as possible (until the upstream source closes the watch or times out,
+//    or you stop the controller).
+//  * h is the object you want notifications sent to.
+//  * indexers is the indexer for the received object type.
+//
+func NewIndexerInformer(
+	lw ListerWatcher,
+	objType runtime.Object,
+	resyncPeriod time.Duration,
+	h ResourceEventHandler,
+	indexers Indexers,
+) (Indexer, Controller) {
+	// This will hold the client state, as we know it.
+	clientState := NewIndexer(DeletionHandlingMetaNamespaceKeyFunc, indexers)
+
+	return clientState, newInformer(lw, objType, resyncPeriod, h, clientState, nil)
+}
+
+// TransformFunc allows for transforming an object before it will be processed
+// and put into the controller cache and before the corresponding handlers will
+// be called on it.
+// TransformFunc (similarly to ResourceEventHandler functions) should be able
+// to correctly handle the tombstone of type cache.DeletedFinalStateUnknown
+//
+// The most common usage pattern is to clean-up some parts of the object to
+// reduce component memory usage if a given component doesn't care about them.
+// given controller doesn't care for them
+type TransformFunc func(interface{}) (interface{}, error)
+
+// NewTransformingInformer returns a Store and a controller for populating
+// the store while also providing event notifications. You should only used
+// the returned Store for Get/List operations; Add/Modify/Deletes will cause
+// the event notifications to be faulty.
+// The given transform function will be called on all objects before they will
+// put into the Store and corresponding Add/Modify/Delete handlers will
+// be invoked for them.
+func NewTransformingInformer(
+	lw ListerWatcher,
+	objType runtime.Object,
+	resyncPeriod time.Duration,
+	h ResourceEventHandler,
+	transformer TransformFunc,
+) (Store, Controller) {
+	// This will hold the client state, as we know it.
+	clientState := NewStore(DeletionHandlingMetaNamespaceKeyFunc)
+
+	return clientState, newInformer(lw, objType, resyncPeriod, h, clientState, transformer)
+}
+
+// NewTransformingIndexerInformer returns an Indexer and a controller for
+// populating the index while also providing event notifications. You should
+// only used the returned Index for Get/List operations; Add/Modify/Deletes
+// will cause the event notifications to be faulty.
+// The given transform function will be called on all objects before they will
+// be put into the Index and corresponding Add/Modify/Delete handlers will
+// be invoked for them.
+func NewTransformingIndexerInformer(
+	lw ListerWatcher,
+	objType runtime.Object,
+	resyncPeriod time.Duration,
+	h ResourceEventHandler,
+	indexers Indexers,
+	transformer TransformFunc,
+) (Indexer, Controller) {
+	// This will hold the client state, as we know it.
+	clientState := NewIndexer(DeletionHandlingMetaNamespaceKeyFunc, indexers)
+
+	return clientState, newInformer(lw, objType, resyncPeriod, h, clientState, transformer)
+}
+
+// Multiplexes updates in the form of a list of Deltas into a Store, and informs
+// a given handler of events OnUpdate, OnAdd, OnDelete
+func processDeltas(
+	// Object which receives event notifications from the given deltas
+	handler ResourceEventHandler,
+	clientState Store,
+	transformer TransformFunc,
+	deltas Deltas,
+) error {
+	// from oldest to newest
+	for _, d := range deltas {
+		obj := d.Object
+		if transformer != nil {
+			var err error
+			obj, err = transformer(obj)
+			if err != nil {
+				return err
+			}
+		}
+
+		switch d.Type {
+		case Sync, Replaced, Added, Updated:
+			if old, exists, err := clientState.Get(obj); err == nil && exists {
+				if err := clientState.Update(obj); err != nil {
+					return err
+				}
+				handler.OnUpdate(old, obj)
+			} else {
+				if err := clientState.Add(obj); err != nil {
+					return err
+				}
+				handler.OnAdd(obj)
+			}
+		case Deleted:
+			if err := clientState.Delete(obj); err != nil {
+				return err
+			}
+			handler.OnDelete(obj)
+		}
+	}
+	return nil
+}
+
+// newInformer returns a controller for populating the store while also
+// providing event notifications.
+//
+// Parameters
+//  * lw is list and watch functions for the source of the resource you want to
+//    be informed of.
+//  * objType is an object of the type that you expect to receive.
+//  * resyncPeriod: if non-zero, will re-list this often (you will get OnUpdate
+//    calls, even if nothing changed). Otherwise, re-list will be delayed as
+//    long as possible (until the upstream source closes the watch or times out,
+//    or you stop the controller).
+//  * h is the object you want notifications sent to.
+//  * clientState is the store you want to populate
+//
+func newInformer(
+	lw ListerWatcher,
+	objType runtime.Object,
+	resyncPeriod time.Duration,
+	h ResourceEventHandler,
+	clientState Store,
+	transformer TransformFunc,
+) Controller {
+	// This will hold incoming changes. Note how we pass clientState in as a
+	// KeyLister, that way resync operations will result in the correct set
+	// of update/delete deltas.
+	fifo := NewDeltaFIFOWithOptions(DeltaFIFOOptions{
+		KnownObjects:          clientState,
+		EmitDeltaTypeReplaced: true,
+	})
+
+	cfg := &Config{
+		Queue:            fifo,
+		ListerWatcher:    lw,
+		ObjectType:       objType,
+		FullResyncPeriod: resyncPeriod,
+		RetryOnError:     false,
+
+		Process: func(obj interface{}) error {
+			if deltas, ok := obj.(Deltas); ok {
+				return processDeltas(h, clientState, transformer, deltas)
+			}
+			return errors.New("object given as Process argument is not Deltas")
+		},
+	}
+	return New(cfg)
+}

vendor/k8s.io/client-go/tools/cache/delta_fifo.go

@@ -0,0 +1,757 @@
+/*
+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 cache
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+
+	"k8s.io/klog/v2"
+	utiltrace "k8s.io/utils/trace"
+)
+
+// DeltaFIFOOptions is the configuration parameters for DeltaFIFO. All are
+// optional.
+type DeltaFIFOOptions struct {
+
+	// KeyFunction is used to figure out what key an object should have. (It's
+	// exposed in the returned DeltaFIFO's KeyOf() method, with additional
+	// handling around deleted objects and queue state).
+	// Optional, the default is MetaNamespaceKeyFunc.
+	KeyFunction KeyFunc
+
+	// KnownObjects is expected to return a list of keys that the consumer of
+	// this queue "knows about". It is used to decide which items are missing
+	// when Replace() is called; 'Deleted' deltas are produced for the missing items.
+	// KnownObjects may be nil if you can tolerate missing deletions on Replace().
+	KnownObjects KeyListerGetter
+
+	// EmitDeltaTypeReplaced indicates that the queue consumer
+	// understands the Replaced DeltaType. Before the `Replaced` event type was
+	// added, calls to Replace() were handled the same as Sync(). For
+	// backwards-compatibility purposes, this is false by default.
+	// When true, `Replaced` events will be sent for items passed to a Replace() call.
+	// When false, `Sync` events will be sent instead.
+	EmitDeltaTypeReplaced bool
+}
+
+// DeltaFIFO is like FIFO, but differs in two ways.  One is that the
+// accumulator associated with a given object's key is not that object
+// but rather a Deltas, which is a slice of Delta values for that
+// object.  Applying an object to a Deltas means to append a Delta
+// except when the potentially appended Delta is a Deleted and the
+// Deltas already ends with a Deleted.  In that case the Deltas does
+// not grow, although the terminal Deleted will be replaced by the new
+// Deleted if the older Deleted's object is a
+// DeletedFinalStateUnknown.
+//
+// The other difference is that DeltaFIFO has two additional ways that
+// an object can be applied to an accumulator: Replaced and Sync.
+// If EmitDeltaTypeReplaced is not set to true, Sync will be used in
+// replace events for backwards compatibility.  Sync is used for periodic
+// resync events.
+//
+// DeltaFIFO is a producer-consumer queue, where a Reflector is
+// intended to be the producer, and the consumer is whatever calls
+// the Pop() method.
+//
+// DeltaFIFO solves this use case:
+//  * You want to process every object change (delta) at most once.
+//  * When you process an object, you want to see everything
+//    that's happened to it since you last processed it.
+//  * You want to process the deletion of some of the objects.
+//  * You might want to periodically reprocess objects.
+//
+// DeltaFIFO's Pop(), Get(), and GetByKey() methods return
+// interface{} to satisfy the Store/Queue interfaces, but they
+// will always return an object of type Deltas. List() returns
+// the newest object from each accumulator in the FIFO.
+//
+// A DeltaFIFO's knownObjects KeyListerGetter provides the abilities
+// to list Store keys and to get objects by Store key.  The objects in
+// question are called "known objects" and this set of objects
+// modifies the behavior of the Delete, Replace, and Resync methods
+// (each in a different way).
+//
+// A note on threading: If you call Pop() in parallel from multiple
+// threads, you could end up with multiple threads processing slightly
+// different versions of the same object.
+type DeltaFIFO struct {
+	// lock/cond protects access to 'items' and 'queue'.
+	lock sync.RWMutex
+	cond sync.Cond
+
+	// `items` maps a key to a Deltas.
+	// Each such Deltas has at least one Delta.
+	items map[string]Deltas
+
+	// `queue` maintains FIFO order of keys for consumption in Pop().
+	// There are no duplicates in `queue`.
+	// A key is in `queue` if and only if it is in `items`.
+	queue []string
+
+	// populated is true if the first batch of items inserted by Replace() has been populated
+	// or Delete/Add/Update/AddIfNotPresent was called first.
+	populated bool
+	// initialPopulationCount is the number of items inserted by the first call of Replace()
+	initialPopulationCount int
+
+	// keyFunc is used to make the key used for queued item
+	// insertion and retrieval, and should be deterministic.
+	keyFunc KeyFunc
+
+	// knownObjects list keys that are "known" --- affecting Delete(),
+	// Replace(), and Resync()
+	knownObjects KeyListerGetter
+
+	// Used to indicate a queue is closed so a control loop can exit when a queue is empty.
+	// Currently, not used to gate any of CRUD operations.
+	closed bool
+
+	// emitDeltaTypeReplaced is whether to emit the Replaced or Sync
+	// DeltaType when Replace() is called (to preserve backwards compat).
+	emitDeltaTypeReplaced bool
+}
+
+// DeltaType is the type of a change (addition, deletion, etc)
+type DeltaType string
+
+// Change type definition
+const (
+	Added   DeltaType = "Added"
+	Updated DeltaType = "Updated"
+	Deleted DeltaType = "Deleted"
+	// Replaced is emitted when we encountered watch errors and had to do a
+	// relist. We don't know if the replaced object has changed.
+	//
+	// NOTE: Previous versions of DeltaFIFO would use Sync for Replace events
+	// as well. Hence, Replaced is only emitted when the option
+	// EmitDeltaTypeReplaced is true.
+	Replaced DeltaType = "Replaced"
+	// Sync is for synthetic events during a periodic resync.
+	Sync DeltaType = "Sync"
+)
+
+// Delta is a member of Deltas (a list of Delta objects) which
+// in its turn is the type stored by a DeltaFIFO. It tells you what
+// change happened, and the object's state after* that change.
+//
+// [*] Unless the change is a deletion, and then you'll get the final
+// state of the object before it was deleted.
+type Delta struct {
+	Type   DeltaType
+	Object interface{}
+}
+
+// Deltas is a list of one or more 'Delta's to an individual object.
+// The oldest delta is at index 0, the newest delta is the last one.
+type Deltas []Delta
+
+// NewDeltaFIFO returns a Queue which can be used to process changes to items.
+//
+// keyFunc is used to figure out what key an object should have. (It is
+// exposed in the returned DeltaFIFO's KeyOf() method, with additional handling
+// around deleted objects and queue state).
+//
+// 'knownObjects' may be supplied to modify the behavior of Delete,
+// Replace, and Resync.  It may be nil if you do not need those
+// modifications.
+//
+// TODO: consider merging keyLister with this object, tracking a list of
+// "known" keys when Pop() is called. Have to think about how that
+// affects error retrying.
+//
+//       NOTE: It is possible to misuse this and cause a race when using an
+//       external known object source.
+//       Whether there is a potential race depends on how the consumer
+//       modifies knownObjects. In Pop(), process function is called under
+//       lock, so it is safe to update data structures in it that need to be
+//       in sync with the queue (e.g. knownObjects).
+//
+//       Example:
+//       In case of sharedIndexInformer being a consumer
+//       (https://github.com/kubernetes/kubernetes/blob/0cdd940f/staging/src/k8s.io/client-go/tools/cache/shared_informer.go#L192),
+//       there is no race as knownObjects (s.indexer) is modified safely
+//       under DeltaFIFO's lock. The only exceptions are GetStore() and
+//       GetIndexer() methods, which expose ways to modify the underlying
+//       storage. Currently these two methods are used for creating Lister
+//       and internal tests.
+//
+// Also see the comment on DeltaFIFO.
+//
+// Warning: This constructs a DeltaFIFO that does not differentiate between
+// events caused by a call to Replace (e.g., from a relist, which may
+// contain object updates), and synthetic events caused by a periodic resync
+// (which just emit the existing object). See https://issue.k8s.io/86015 for details.
+//
+// Use `NewDeltaFIFOWithOptions(DeltaFIFOOptions{..., EmitDeltaTypeReplaced: true})`
+// instead to receive a `Replaced` event depending on the type.
+//
+// Deprecated: Equivalent to NewDeltaFIFOWithOptions(DeltaFIFOOptions{KeyFunction: keyFunc, KnownObjects: knownObjects})
+func NewDeltaFIFO(keyFunc KeyFunc, knownObjects KeyListerGetter) *DeltaFIFO {
+	return NewDeltaFIFOWithOptions(DeltaFIFOOptions{
+		KeyFunction:  keyFunc,
+		KnownObjects: knownObjects,
+	})
+}
+
+// NewDeltaFIFOWithOptions returns a Queue which can be used to process changes to
+// items. See also the comment on DeltaFIFO.
+func NewDeltaFIFOWithOptions(opts DeltaFIFOOptions) *DeltaFIFO {
+	if opts.KeyFunction == nil {
+		opts.KeyFunction = MetaNamespaceKeyFunc
+	}
+
+	f := &DeltaFIFO{
+		items:        map[string]Deltas{},
+		queue:        []string{},
+		keyFunc:      opts.KeyFunction,
+		knownObjects: opts.KnownObjects,
+
+		emitDeltaTypeReplaced: opts.EmitDeltaTypeReplaced,
+	}
+	f.cond.L = &f.lock
+	return f
+}
+
+var (
+	_ = Queue(&DeltaFIFO{}) // DeltaFIFO is a Queue
+)
+
+var (
+	// ErrZeroLengthDeltasObject is returned in a KeyError if a Deltas
+	// object with zero length is encountered (should be impossible,
+	// but included for completeness).
+	ErrZeroLengthDeltasObject = errors.New("0 length Deltas object; can't get key")
+)
+
+// Close the queue.
+func (f *DeltaFIFO) Close() {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.closed = true
+	f.cond.Broadcast()
+}
+
+// KeyOf exposes f's keyFunc, but also detects the key of a Deltas object or
+// DeletedFinalStateUnknown objects.
+func (f *DeltaFIFO) KeyOf(obj interface{}) (string, error) {
+	if d, ok := obj.(Deltas); ok {
+		if len(d) == 0 {
+			return "", KeyError{obj, ErrZeroLengthDeltasObject}
+		}
+		obj = d.Newest().Object
+	}
+	if d, ok := obj.(DeletedFinalStateUnknown); ok {
+		return d.Key, nil
+	}
+	return f.keyFunc(obj)
+}
+
+// HasSynced returns true if an Add/Update/Delete/AddIfNotPresent are called first,
+// or the first batch of items inserted by Replace() has been popped.
+func (f *DeltaFIFO) HasSynced() bool {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	return f.populated && f.initialPopulationCount == 0
+}
+
+// Add inserts an item, and puts it in the queue. The item is only enqueued
+// if it doesn't already exist in the set.
+func (f *DeltaFIFO) Add(obj interface{}) error {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.populated = true
+	return f.queueActionLocked(Added, obj)
+}
+
+// Update is just like Add, but makes an Updated Delta.
+func (f *DeltaFIFO) Update(obj interface{}) error {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.populated = true
+	return f.queueActionLocked(Updated, obj)
+}
+
+// Delete is just like Add, but makes a Deleted Delta. If the given
+// object does not already exist, it will be ignored. (It may have
+// already been deleted by a Replace (re-list), for example.)  In this
+// method `f.knownObjects`, if not nil, provides (via GetByKey)
+// _additional_ objects that are considered to already exist.
+func (f *DeltaFIFO) Delete(obj interface{}) error {
+	id, err := f.KeyOf(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.populated = true
+	if f.knownObjects == nil {
+		if _, exists := f.items[id]; !exists {
+			// Presumably, this was deleted when a relist happened.
+			// Don't provide a second report of the same deletion.
+			return nil
+		}
+	} else {
+		// We only want to skip the "deletion" action if the object doesn't
+		// exist in knownObjects and it doesn't have corresponding item in items.
+		// Note that even if there is a "deletion" action in items, we can ignore it,
+		// because it will be deduped automatically in "queueActionLocked"
+		_, exists, err := f.knownObjects.GetByKey(id)
+		_, itemsExist := f.items[id]
+		if err == nil && !exists && !itemsExist {
+			// Presumably, this was deleted when a relist happened.
+			// Don't provide a second report of the same deletion.
+			return nil
+		}
+	}
+
+	// exist in items and/or KnownObjects
+	return f.queueActionLocked(Deleted, obj)
+}
+
+// AddIfNotPresent inserts an item, and puts it in the queue. If the item is already
+// present in the set, it is neither enqueued nor added to the set.
+//
+// This is useful in a single producer/consumer scenario so that the consumer can
+// safely retry items without contending with the producer and potentially enqueueing
+// stale items.
+//
+// Important: obj must be a Deltas (the output of the Pop() function). Yes, this is
+// different from the Add/Update/Delete functions.
+func (f *DeltaFIFO) AddIfNotPresent(obj interface{}) error {
+	deltas, ok := obj.(Deltas)
+	if !ok {
+		return fmt.Errorf("object must be of type deltas, but got: %#v", obj)
+	}
+	id, err := f.KeyOf(deltas)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.addIfNotPresent(id, deltas)
+	return nil
+}
+
+// addIfNotPresent inserts deltas under id if it does not exist, and assumes the caller
+// already holds the fifo lock.
+func (f *DeltaFIFO) addIfNotPresent(id string, deltas Deltas) {
+	f.populated = true
+	if _, exists := f.items[id]; exists {
+		return
+	}
+
+	f.queue = append(f.queue, id)
+	f.items[id] = deltas
+	f.cond.Broadcast()
+}
+
+// re-listing and watching can deliver the same update multiple times in any
+// order. This will combine the most recent two deltas if they are the same.
+func dedupDeltas(deltas Deltas) Deltas {
+	n := len(deltas)
+	if n < 2 {
+		return deltas
+	}
+	a := &deltas[n-1]
+	b := &deltas[n-2]
+	if out := isDup(a, b); out != nil {
+		deltas[n-2] = *out
+		return deltas[:n-1]
+	}
+	return deltas
+}
+
+// If a & b represent the same event, returns the delta that ought to be kept.
+// Otherwise, returns nil.
+// TODO: is there anything other than deletions that need deduping?
+func isDup(a, b *Delta) *Delta {
+	if out := isDeletionDup(a, b); out != nil {
+		return out
+	}
+	// TODO: Detect other duplicate situations? Are there any?
+	return nil
+}
+
+// keep the one with the most information if both are deletions.
+func isDeletionDup(a, b *Delta) *Delta {
+	if b.Type != Deleted || a.Type != Deleted {
+		return nil
+	}
+	// Do more sophisticated checks, or is this sufficient?
+	if _, ok := b.Object.(DeletedFinalStateUnknown); ok {
+		return a
+	}
+	return b
+}
+
+// queueActionLocked appends to the delta list for the object.
+// Caller must lock first.
+func (f *DeltaFIFO) queueActionLocked(actionType DeltaType, obj interface{}) error {
+	id, err := f.KeyOf(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	oldDeltas := f.items[id]
+	newDeltas := append(oldDeltas, Delta{actionType, obj})
+	newDeltas = dedupDeltas(newDeltas)
+
+	if len(newDeltas) > 0 {
+		if _, exists := f.items[id]; !exists {
+			f.queue = append(f.queue, id)
+		}
+		f.items[id] = newDeltas
+		f.cond.Broadcast()
+	} else {
+		// This never happens, because dedupDeltas never returns an empty list
+		// when given a non-empty list (as it is here).
+		// If somehow it happens anyway, deal with it but complain.
+		if oldDeltas == nil {
+			klog.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; ignoring", id, oldDeltas, obj)
+			return nil
+		}
+		klog.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; breaking invariant by storing empty Deltas", id, oldDeltas, obj)
+		f.items[id] = newDeltas
+		return fmt.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; broke DeltaFIFO invariant by storing empty Deltas", id, oldDeltas, obj)
+	}
+	return nil
+}
+
+// List returns a list of all the items; it returns the object
+// from the most recent Delta.
+// You should treat the items returned inside the deltas as immutable.
+func (f *DeltaFIFO) List() []interface{} {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	return f.listLocked()
+}
+
+func (f *DeltaFIFO) listLocked() []interface{} {
+	list := make([]interface{}, 0, len(f.items))
+	for _, item := range f.items {
+		list = append(list, item.Newest().Object)
+	}
+	return list
+}
+
+// ListKeys returns a list of all the keys of the objects currently
+// in the FIFO.
+func (f *DeltaFIFO) ListKeys() []string {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	list := make([]string, 0, len(f.queue))
+	for _, key := range f.queue {
+		list = append(list, key)
+	}
+	return list
+}
+
+// Get returns the complete list of deltas for the requested item,
+// or sets exists=false.
+// You should treat the items returned inside the deltas as immutable.
+func (f *DeltaFIFO) Get(obj interface{}) (item interface{}, exists bool, err error) {
+	key, err := f.KeyOf(obj)
+	if err != nil {
+		return nil, false, KeyError{obj, err}
+	}
+	return f.GetByKey(key)
+}
+
+// GetByKey returns the complete list of deltas for the requested item,
+// setting exists=false if that list is empty.
+// You should treat the items returned inside the deltas as immutable.
+func (f *DeltaFIFO) GetByKey(key string) (item interface{}, exists bool, err error) {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	d, exists := f.items[key]
+	if exists {
+		// Copy item's slice so operations on this slice
+		// won't interfere with the object we return.
+		d = copyDeltas(d)
+	}
+	return d, exists, nil
+}
+
+// IsClosed checks if the queue is closed
+func (f *DeltaFIFO) IsClosed() bool {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	return f.closed
+}
+
+// Pop blocks until the queue has some items, and then returns one.  If
+// multiple items are ready, they are returned in the order in which they were
+// added/updated. The item is removed from the queue (and the store) before it
+// is returned, so if you don't successfully process it, you need to add it back
+// with AddIfNotPresent().
+// process function is called under lock, so it is safe to update data structures
+// in it that need to be in sync with the queue (e.g. knownKeys). The PopProcessFunc
+// may return an instance of ErrRequeue with a nested error to indicate the current
+// item should be requeued (equivalent to calling AddIfNotPresent under the lock).
+// process should avoid expensive I/O operation so that other queue operations, i.e.
+// Add() and Get(), won't be blocked for too long.
+//
+// Pop returns a 'Deltas', which has a complete list of all the things
+// that happened to the object (deltas) while it was sitting in the queue.
+func (f *DeltaFIFO) Pop(process PopProcessFunc) (interface{}, error) {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	for {
+		for len(f.queue) == 0 {
+			// When the queue is empty, invocation of Pop() is blocked until new item is enqueued.
+			// When Close() is called, the f.closed is set and the condition is broadcasted.
+			// Which causes this loop to continue and return from the Pop().
+			if f.closed {
+				return nil, ErrFIFOClosed
+			}
+
+			f.cond.Wait()
+		}
+		id := f.queue[0]
+		f.queue = f.queue[1:]
+		depth := len(f.queue)
+		if f.initialPopulationCount > 0 {
+			f.initialPopulationCount--
+		}
+		item, ok := f.items[id]
+		if !ok {
+			// This should never happen
+			klog.Errorf("Inconceivable! %q was in f.queue but not f.items; ignoring.", id)
+			continue
+		}
+		delete(f.items, id)
+		// Only log traces if the queue depth is greater than 10 and it takes more than
+		// 100 milliseconds to process one item from the queue.
+		// Queue depth never goes high because processing an item is locking the queue,
+		// and new items can't be added until processing finish.
+		// https://github.com/kubernetes/kubernetes/issues/103789
+		if depth > 10 {
+			trace := utiltrace.New("DeltaFIFO Pop Process",
+				utiltrace.Field{Key: "ID", Value: id},
+				utiltrace.Field{Key: "Depth", Value: depth},
+				utiltrace.Field{Key: "Reason", Value: "slow event handlers blocking the queue"})
+			defer trace.LogIfLong(100 * time.Millisecond)
+		}
+		err := process(item)
+		if e, ok := err.(ErrRequeue); ok {
+			f.addIfNotPresent(id, item)
+			err = e.Err
+		}
+		// Don't need to copyDeltas here, because we're transferring
+		// ownership to the caller.
+		return item, err
+	}
+}
+
+// Replace atomically does two things: (1) it adds the given objects
+// using the Sync or Replace DeltaType and then (2) it does some deletions.
+// In particular: for every pre-existing key K that is not the key of
+// an object in `list` there is the effect of
+// `Delete(DeletedFinalStateUnknown{K, O})` where O is current object
+// of K.  If `f.knownObjects == nil` then the pre-existing keys are
+// those in `f.items` and the current object of K is the `.Newest()`
+// of the Deltas associated with K.  Otherwise the pre-existing keys
+// are those listed by `f.knownObjects` and the current object of K is
+// what `f.knownObjects.GetByKey(K)` returns.
+func (f *DeltaFIFO) Replace(list []interface{}, _ string) error {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	keys := make(sets.String, len(list))
+
+	// keep backwards compat for old clients
+	action := Sync
+	if f.emitDeltaTypeReplaced {
+		action = Replaced
+	}
+
+	// Add Sync/Replaced action for each new item.
+	for _, item := range list {
+		key, err := f.KeyOf(item)
+		if err != nil {
+			return KeyError{item, err}
+		}
+		keys.Insert(key)
+		if err := f.queueActionLocked(action, item); err != nil {
+			return fmt.Errorf("couldn't enqueue object: %v", err)
+		}
+	}
+
+	if f.knownObjects == nil {
+		// Do deletion detection against our own list.
+		queuedDeletions := 0
+		for k, oldItem := range f.items {
+			if keys.Has(k) {
+				continue
+			}
+			// Delete pre-existing items not in the new list.
+			// This could happen if watch deletion event was missed while
+			// disconnected from apiserver.
+			var deletedObj interface{}
+			if n := oldItem.Newest(); n != nil {
+				deletedObj = n.Object
+			}
+			queuedDeletions++
+			if err := f.queueActionLocked(Deleted, DeletedFinalStateUnknown{k, deletedObj}); err != nil {
+				return err
+			}
+		}
+
+		if !f.populated {
+			f.populated = true
+			// While there shouldn't be any queued deletions in the initial
+			// population of the queue, it's better to be on the safe side.
+			f.initialPopulationCount = keys.Len() + queuedDeletions
+		}
+
+		return nil
+	}
+
+	// Detect deletions not already in the queue.
+	knownKeys := f.knownObjects.ListKeys()
+	queuedDeletions := 0
+	for _, k := range knownKeys {
+		if keys.Has(k) {
+			continue
+		}
+
+		deletedObj, exists, err := f.knownObjects.GetByKey(k)
+		if err != nil {
+			deletedObj = nil
+			klog.Errorf("Unexpected error %v during lookup of key %v, placing DeleteFinalStateUnknown marker without object", err, k)
+		} else if !exists {
+			deletedObj = nil
+			klog.Infof("Key %v does not exist in known objects store, placing DeleteFinalStateUnknown marker without object", k)
+		}
+		queuedDeletions++
+		if err := f.queueActionLocked(Deleted, DeletedFinalStateUnknown{k, deletedObj}); err != nil {
+			return err
+		}
+	}
+
+	if !f.populated {
+		f.populated = true
+		f.initialPopulationCount = keys.Len() + queuedDeletions
+	}
+
+	return nil
+}
+
+// Resync adds, with a Sync type of Delta, every object listed by
+// `f.knownObjects` whose key is not already queued for processing.
+// If `f.knownObjects` is `nil` then Resync does nothing.
+func (f *DeltaFIFO) Resync() error {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+
+	if f.knownObjects == nil {
+		return nil
+	}
+
+	keys := f.knownObjects.ListKeys()
+	for _, k := range keys {
+		if err := f.syncKeyLocked(k); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (f *DeltaFIFO) syncKeyLocked(key string) error {
+	obj, exists, err := f.knownObjects.GetByKey(key)
+	if err != nil {
+		klog.Errorf("Unexpected error %v during lookup of key %v, unable to queue object for sync", err, key)
+		return nil
+	} else if !exists {
+		klog.Infof("Key %v does not exist in known objects store, unable to queue object for sync", key)
+		return nil
+	}
+
+	// If we are doing Resync() and there is already an event queued for that object,
+	// we ignore the Resync for it. This is to avoid the race, in which the resync
+	// comes with the previous value of object (since queueing an event for the object
+	// doesn't trigger changing the underlying store <knownObjects>.
+	id, err := f.KeyOf(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	if len(f.items[id]) > 0 {
+		return nil
+	}
+
+	if err := f.queueActionLocked(Sync, obj); err != nil {
+		return fmt.Errorf("couldn't queue object: %v", err)
+	}
+	return nil
+}
+
+// A KeyListerGetter is anything that knows how to list its keys and look up by key.
+type KeyListerGetter interface {
+	KeyLister
+	KeyGetter
+}
+
+// A KeyLister is anything that knows how to list its keys.
+type KeyLister interface {
+	ListKeys() []string
+}
+
+// A KeyGetter is anything that knows how to get the value stored under a given key.
+type KeyGetter interface {
+	// GetByKey returns the value associated with the key, or sets exists=false.
+	GetByKey(key string) (value interface{}, exists bool, err error)
+}
+
+// Oldest is a convenience function that returns the oldest delta, or
+// nil if there are no deltas.
+func (d Deltas) Oldest() *Delta {
+	if len(d) > 0 {
+		return &d[0]
+	}
+	return nil
+}
+
+// Newest is a convenience function that returns the newest delta, or
+// nil if there are no deltas.
+func (d Deltas) Newest() *Delta {
+	if n := len(d); n > 0 {
+		return &d[n-1]
+	}
+	return nil
+}
+
+// copyDeltas returns a shallow copy of d; that is, it copies the slice but not
+// the objects in the slice. This allows Get/List to return an object that we
+// know won't be clobbered by a subsequent modifications.
+func copyDeltas(d Deltas) Deltas {
+	d2 := make(Deltas, len(d))
+	copy(d2, d)
+	return d2
+}
+
+// DeletedFinalStateUnknown is placed into a DeltaFIFO in the case where an object
+// was deleted but the watch deletion event was missed while disconnected from
+// apiserver. In this case we don't know the final "resting" state of the object, so
+// there's a chance the included `Obj` is stale.
+type DeletedFinalStateUnknown struct {
+	Key string
+	Obj interface{}
+}

vendor/k8s.io/client-go/tools/cache/doc.go

@@ -0,0 +1,24 @@
+/*
+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 cache is a client-side caching mechanism. It is useful for
+// reducing the number of server calls you'd otherwise need to make.
+// Reflector watches a server and updates a Store. Two stores are provided;
+// one that simply caches objects (for example, to allow a scheduler to
+// list currently available nodes), and one that additionally acts as
+// a FIFO queue (for example, to allow a scheduler to process incoming
+// pods).
+package cache // import "k8s.io/client-go/tools/cache"

vendor/k8s.io/client-go/tools/cache/expiration_cache.go

@@ -0,0 +1,215 @@
+/*
+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 cache
+
+import (
+	"sync"
+	"time"
+
+	"k8s.io/klog/v2"
+	"k8s.io/utils/clock"
+)
+
+// ExpirationCache implements the store interface
+//	1. All entries are automatically time stamped on insert
+//		a. The key is computed based off the original item/keyFunc
+//		b. The value inserted under that key is the timestamped item
+//	2. Expiration happens lazily on read based on the expiration policy
+//      a. No item can be inserted into the store while we're expiring
+//		   *any* item in the cache.
+//	3. Time-stamps are stripped off unexpired entries before return
+// Note that the ExpirationCache is inherently slower than a normal
+// threadSafeStore because it takes a write lock every time it checks if
+// an item has expired.
+type ExpirationCache struct {
+	cacheStorage     ThreadSafeStore
+	keyFunc          KeyFunc
+	clock            clock.Clock
+	expirationPolicy ExpirationPolicy
+	// expirationLock is a write lock used to guarantee that we don't clobber
+	// newly inserted objects because of a stale expiration timestamp comparison
+	expirationLock sync.Mutex
+}
+
+// ExpirationPolicy dictates when an object expires. Currently only abstracted out
+// so unittests don't rely on the system clock.
+type ExpirationPolicy interface {
+	IsExpired(obj *TimestampedEntry) bool
+}
+
+// TTLPolicy implements a ttl based ExpirationPolicy.
+type TTLPolicy struct {
+	//	 >0: Expire entries with an age > ttl
+	//	<=0: Don't expire any entry
+	TTL time.Duration
+
+	// Clock used to calculate ttl expiration
+	Clock clock.Clock
+}
+
+// IsExpired returns true if the given object is older than the ttl, or it can't
+// determine its age.
+func (p *TTLPolicy) IsExpired(obj *TimestampedEntry) bool {
+	return p.TTL > 0 && p.Clock.Since(obj.Timestamp) > p.TTL
+}
+
+// TimestampedEntry is the only type allowed in a ExpirationCache.
+// Keep in mind that it is not safe to share timestamps between computers.
+// Behavior may be inconsistent if you get a timestamp from the API Server and
+// use it on the client machine as part of your ExpirationCache.
+type TimestampedEntry struct {
+	Obj       interface{}
+	Timestamp time.Time
+	key       string
+}
+
+// getTimestampedEntry returns the TimestampedEntry stored under the given key.
+func (c *ExpirationCache) getTimestampedEntry(key string) (*TimestampedEntry, bool) {
+	item, _ := c.cacheStorage.Get(key)
+	if tsEntry, ok := item.(*TimestampedEntry); ok {
+		return tsEntry, true
+	}
+	return nil, false
+}
+
+// getOrExpire retrieves the object from the TimestampedEntry if and only if it hasn't
+// already expired. It holds a write lock across deletion.
+func (c *ExpirationCache) getOrExpire(key string) (interface{}, bool) {
+	// Prevent all inserts from the time we deem an item as "expired" to when we
+	// delete it, so an un-expired item doesn't sneak in under the same key, just
+	// before the Delete.
+	c.expirationLock.Lock()
+	defer c.expirationLock.Unlock()
+	timestampedItem, exists := c.getTimestampedEntry(key)
+	if !exists {
+		return nil, false
+	}
+	if c.expirationPolicy.IsExpired(timestampedItem) {
+		klog.V(4).Infof("Entry %v: %+v has expired", key, timestampedItem.Obj)
+		c.cacheStorage.Delete(key)
+		return nil, false
+	}
+	return timestampedItem.Obj, true
+}
+
+// GetByKey returns the item stored under the key, or sets exists=false.
+func (c *ExpirationCache) GetByKey(key string) (interface{}, bool, error) {
+	obj, exists := c.getOrExpire(key)
+	return obj, exists, nil
+}
+
+// Get returns unexpired items. It purges the cache of expired items in the
+// process.
+func (c *ExpirationCache) Get(obj interface{}) (interface{}, bool, error) {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return nil, false, KeyError{obj, err}
+	}
+	obj, exists := c.getOrExpire(key)
+	return obj, exists, nil
+}
+
+// List retrieves a list of unexpired items. It purges the cache of expired
+// items in the process.
+func (c *ExpirationCache) List() []interface{} {
+	items := c.cacheStorage.List()
+
+	list := make([]interface{}, 0, len(items))
+	for _, item := range items {
+		key := item.(*TimestampedEntry).key
+		if obj, exists := c.getOrExpire(key); exists {
+			list = append(list, obj)
+		}
+	}
+	return list
+}
+
+// ListKeys returns a list of all keys in the expiration cache.
+func (c *ExpirationCache) ListKeys() []string {
+	return c.cacheStorage.ListKeys()
+}
+
+// Add timestamps an item and inserts it into the cache, overwriting entries
+// that might exist under the same key.
+func (c *ExpirationCache) Add(obj interface{}) error {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	c.expirationLock.Lock()
+	defer c.expirationLock.Unlock()
+
+	c.cacheStorage.Add(key, &TimestampedEntry{obj, c.clock.Now(), key})
+	return nil
+}
+
+// Update has not been implemented yet for lack of a use case, so this method
+// simply calls `Add`. This effectively refreshes the timestamp.
+func (c *ExpirationCache) Update(obj interface{}) error {
+	return c.Add(obj)
+}
+
+// Delete removes an item from the cache.
+func (c *ExpirationCache) Delete(obj interface{}) error {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	c.expirationLock.Lock()
+	defer c.expirationLock.Unlock()
+	c.cacheStorage.Delete(key)
+	return nil
+}
+
+// Replace will convert all items in the given list to TimestampedEntries
+// before attempting the replace operation. The replace operation will
+// delete the contents of the ExpirationCache `c`.
+func (c *ExpirationCache) Replace(list []interface{}, resourceVersion string) error {
+	items := make(map[string]interface{}, len(list))
+	ts := c.clock.Now()
+	for _, item := range list {
+		key, err := c.keyFunc(item)
+		if err != nil {
+			return KeyError{item, err}
+		}
+		items[key] = &TimestampedEntry{item, ts, key}
+	}
+	c.expirationLock.Lock()
+	defer c.expirationLock.Unlock()
+	c.cacheStorage.Replace(items, resourceVersion)
+	return nil
+}
+
+// Resync is a no-op for one of these
+func (c *ExpirationCache) Resync() error {
+	return nil
+}
+
+// NewTTLStore creates and returns a ExpirationCache with a TTLPolicy
+func NewTTLStore(keyFunc KeyFunc, ttl time.Duration) Store {
+	return NewExpirationStore(keyFunc, &TTLPolicy{ttl, clock.RealClock{}})
+}
+
+// NewExpirationStore creates and returns a ExpirationCache for a given policy
+func NewExpirationStore(keyFunc KeyFunc, expirationPolicy ExpirationPolicy) Store {
+	return &ExpirationCache{
+		cacheStorage:     NewThreadSafeStore(Indexers{}, Indices{}),
+		keyFunc:          keyFunc,
+		clock:            clock.RealClock{},
+		expirationPolicy: expirationPolicy,
+	}
+}

vendor/k8s.io/client-go/tools/cache/expiration_cache_fakes.go

@@ -0,0 +1,57 @@
+/*
+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 cache
+
+import (
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/utils/clock"
+)
+
+type fakeThreadSafeMap struct {
+	ThreadSafeStore
+	deletedKeys chan<- string
+}
+
+func (c *fakeThreadSafeMap) Delete(key string) {
+	if c.deletedKeys != nil {
+		c.ThreadSafeStore.Delete(key)
+		c.deletedKeys <- key
+	}
+}
+
+// FakeExpirationPolicy keeps the list for keys which never expires.
+type FakeExpirationPolicy struct {
+	NeverExpire     sets.String
+	RetrieveKeyFunc KeyFunc
+}
+
+// IsExpired used to check if object is expired.
+func (p *FakeExpirationPolicy) IsExpired(obj *TimestampedEntry) bool {
+	key, _ := p.RetrieveKeyFunc(obj)
+	return !p.NeverExpire.Has(key)
+}
+
+// NewFakeExpirationStore creates a new instance for the ExpirationCache.
+func NewFakeExpirationStore(keyFunc KeyFunc, deletedKeys chan<- string, expirationPolicy ExpirationPolicy, cacheClock clock.Clock) Store {
+	cacheStorage := NewThreadSafeStore(Indexers{}, Indices{})
+	return &ExpirationCache{
+		cacheStorage:     &fakeThreadSafeMap{cacheStorage, deletedKeys},
+		keyFunc:          keyFunc,
+		clock:            cacheClock,
+		expirationPolicy: expirationPolicy,
+	}
+}

vendor/k8s.io/client-go/tools/cache/fake_custom_store.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2016 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 cache
+
+// FakeCustomStore lets you define custom functions for store operations.
+type FakeCustomStore struct {
+	AddFunc      func(obj interface{}) error
+	UpdateFunc   func(obj interface{}) error
+	DeleteFunc   func(obj interface{}) error
+	ListFunc     func() []interface{}
+	ListKeysFunc func() []string
+	GetFunc      func(obj interface{}) (item interface{}, exists bool, err error)
+	GetByKeyFunc func(key string) (item interface{}, exists bool, err error)
+	ReplaceFunc  func(list []interface{}, resourceVersion string) error
+	ResyncFunc   func() error
+}
+
+// Add calls the custom Add function if defined
+func (f *FakeCustomStore) Add(obj interface{}) error {
+	if f.AddFunc != nil {
+		return f.AddFunc(obj)
+	}
+	return nil
+}
+
+// Update calls the custom Update function if defined
+func (f *FakeCustomStore) Update(obj interface{}) error {
+	if f.UpdateFunc != nil {
+		return f.UpdateFunc(obj)
+	}
+	return nil
+}
+
+// Delete calls the custom Delete function if defined
+func (f *FakeCustomStore) Delete(obj interface{}) error {
+	if f.DeleteFunc != nil {
+		return f.DeleteFunc(obj)
+	}
+	return nil
+}
+
+// List calls the custom List function if defined
+func (f *FakeCustomStore) List() []interface{} {
+	if f.ListFunc != nil {
+		return f.ListFunc()
+	}
+	return nil
+}
+
+// ListKeys calls the custom ListKeys function if defined
+func (f *FakeCustomStore) ListKeys() []string {
+	if f.ListKeysFunc != nil {
+		return f.ListKeysFunc()
+	}
+	return nil
+}
+
+// Get calls the custom Get function if defined
+func (f *FakeCustomStore) Get(obj interface{}) (item interface{}, exists bool, err error) {
+	if f.GetFunc != nil {
+		return f.GetFunc(obj)
+	}
+	return nil, false, nil
+}
+
+// GetByKey calls the custom GetByKey function if defined
+func (f *FakeCustomStore) GetByKey(key string) (item interface{}, exists bool, err error) {
+	if f.GetByKeyFunc != nil {
+		return f.GetByKeyFunc(key)
+	}
+	return nil, false, nil
+}
+
+// Replace calls the custom Replace function if defined
+func (f *FakeCustomStore) Replace(list []interface{}, resourceVersion string) error {
+	if f.ReplaceFunc != nil {
+		return f.ReplaceFunc(list, resourceVersion)
+	}
+	return nil
+}
+
+// Resync calls the custom Resync function if defined
+func (f *FakeCustomStore) Resync() error {
+	if f.ResyncFunc != nil {
+		return f.ResyncFunc()
+	}
+	return nil
+}

vendor/k8s.io/client-go/tools/cache/fifo.go

@@ -0,0 +1,373 @@
+/*
+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 cache
+
+import (
+	"errors"
+	"sync"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// PopProcessFunc is passed to Pop() method of Queue interface.
+// It is supposed to process the accumulator popped from the queue.
+type PopProcessFunc func(interface{}) error
+
+// ErrRequeue may be returned by a PopProcessFunc to safely requeue
+// the current item. The value of Err will be returned from Pop.
+type ErrRequeue struct {
+	// Err is returned by the Pop function
+	Err error
+}
+
+// ErrFIFOClosed used when FIFO is closed
+var ErrFIFOClosed = errors.New("DeltaFIFO: manipulating with closed queue")
+
+func (e ErrRequeue) Error() string {
+	if e.Err == nil {
+		return "the popped item should be requeued without returning an error"
+	}
+	return e.Err.Error()
+}
+
+// Queue extends Store with a collection of Store keys to "process".
+// Every Add, Update, or Delete may put the object's key in that collection.
+// A Queue has a way to derive the corresponding key given an accumulator.
+// A Queue can be accessed concurrently from multiple goroutines.
+// A Queue can be "closed", after which Pop operations return an error.
+type Queue interface {
+	Store
+
+	// Pop blocks until there is at least one key to process or the
+	// Queue is closed.  In the latter case Pop returns with an error.
+	// In the former case Pop atomically picks one key to process,
+	// removes that (key, accumulator) association from the Store, and
+	// processes the accumulator.  Pop returns the accumulator that
+	// was processed and the result of processing.  The PopProcessFunc
+	// may return an ErrRequeue{inner} and in this case Pop will (a)
+	// return that (key, accumulator) association to the Queue as part
+	// of the atomic processing and (b) return the inner error from
+	// Pop.
+	Pop(PopProcessFunc) (interface{}, error)
+
+	// AddIfNotPresent puts the given accumulator into the Queue (in
+	// association with the accumulator's key) if and only if that key
+	// is not already associated with a non-empty accumulator.
+	AddIfNotPresent(interface{}) error
+
+	// HasSynced returns true if the first batch of keys have all been
+	// popped.  The first batch of keys are those of the first Replace
+	// operation if that happened before any Add, AddIfNotPresent,
+	// Update, or Delete; otherwise the first batch is empty.
+	HasSynced() bool
+
+	// Close the queue
+	Close()
+}
+
+// Pop is helper function for popping from Queue.
+// WARNING: Do NOT use this function in non-test code to avoid races
+// unless you really really really really know what you are doing.
+func Pop(queue Queue) interface{} {
+	var result interface{}
+	queue.Pop(func(obj interface{}) error {
+		result = obj
+		return nil
+	})
+	return result
+}
+
+// FIFO is a Queue in which (a) each accumulator is simply the most
+// recently provided object and (b) the collection of keys to process
+// is a FIFO.  The accumulators all start out empty, and deleting an
+// object from its accumulator empties the accumulator.  The Resync
+// operation is a no-op.
+//
+// Thus: if multiple adds/updates of a single object happen while that
+// object's key is in the queue before it has been processed then it
+// will only be processed once, and when it is processed the most
+// recent version will be processed. This can't be done with a channel
+//
+// FIFO solves this use case:
+//  * You want to process every object (exactly) once.
+//  * You want to process the most recent version of the object when you process it.
+//  * You do not want to process deleted objects, they should be removed from the queue.
+//  * You do not want to periodically reprocess objects.
+// Compare with DeltaFIFO for other use cases.
+type FIFO struct {
+	lock sync.RWMutex
+	cond sync.Cond
+	// We depend on the property that every key in `items` is also in `queue`
+	items map[string]interface{}
+	queue []string
+
+	// populated is true if the first batch of items inserted by Replace() has been populated
+	// or Delete/Add/Update was called first.
+	populated bool
+	// initialPopulationCount is the number of items inserted by the first call of Replace()
+	initialPopulationCount int
+
+	// keyFunc is used to make the key used for queued item insertion and retrieval, and
+	// should be deterministic.
+	keyFunc KeyFunc
+
+	// Indication the queue is closed.
+	// Used to indicate a queue is closed so a control loop can exit when a queue is empty.
+	// Currently, not used to gate any of CRUD operations.
+	closed bool
+}
+
+var (
+	_ = Queue(&FIFO{}) // FIFO is a Queue
+)
+
+// Close the queue.
+func (f *FIFO) Close() {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.closed = true
+	f.cond.Broadcast()
+}
+
+// HasSynced returns true if an Add/Update/Delete/AddIfNotPresent are called first,
+// or the first batch of items inserted by Replace() has been popped.
+func (f *FIFO) HasSynced() bool {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	return f.populated && f.initialPopulationCount == 0
+}
+
+// Add inserts an item, and puts it in the queue. The item is only enqueued
+// if it doesn't already exist in the set.
+func (f *FIFO) Add(obj interface{}) error {
+	id, err := f.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.populated = true
+	if _, exists := f.items[id]; !exists {
+		f.queue = append(f.queue, id)
+	}
+	f.items[id] = obj
+	f.cond.Broadcast()
+	return nil
+}
+
+// AddIfNotPresent inserts an item, and puts it in the queue. If the item is already
+// present in the set, it is neither enqueued nor added to the set.
+//
+// This is useful in a single producer/consumer scenario so that the consumer can
+// safely retry items without contending with the producer and potentially enqueueing
+// stale items.
+func (f *FIFO) AddIfNotPresent(obj interface{}) error {
+	id, err := f.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.addIfNotPresent(id, obj)
+	return nil
+}
+
+// addIfNotPresent assumes the fifo lock is already held and adds the provided
+// item to the queue under id if it does not already exist.
+func (f *FIFO) addIfNotPresent(id string, obj interface{}) {
+	f.populated = true
+	if _, exists := f.items[id]; exists {
+		return
+	}
+
+	f.queue = append(f.queue, id)
+	f.items[id] = obj
+	f.cond.Broadcast()
+}
+
+// Update is the same as Add in this implementation.
+func (f *FIFO) Update(obj interface{}) error {
+	return f.Add(obj)
+}
+
+// Delete removes an item. It doesn't add it to the queue, because
+// this implementation assumes the consumer only cares about the objects,
+// not the order in which they were created/added.
+func (f *FIFO) Delete(obj interface{}) error {
+	id, err := f.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	f.populated = true
+	delete(f.items, id)
+	return err
+}
+
+// List returns a list of all the items.
+func (f *FIFO) List() []interface{} {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	list := make([]interface{}, 0, len(f.items))
+	for _, item := range f.items {
+		list = append(list, item)
+	}
+	return list
+}
+
+// ListKeys returns a list of all the keys of the objects currently
+// in the FIFO.
+func (f *FIFO) ListKeys() []string {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	list := make([]string, 0, len(f.items))
+	for key := range f.items {
+		list = append(list, key)
+	}
+	return list
+}
+
+// Get returns the requested item, or sets exists=false.
+func (f *FIFO) Get(obj interface{}) (item interface{}, exists bool, err error) {
+	key, err := f.keyFunc(obj)
+	if err != nil {
+		return nil, false, KeyError{obj, err}
+	}
+	return f.GetByKey(key)
+}
+
+// GetByKey returns the requested item, or sets exists=false.
+func (f *FIFO) GetByKey(key string) (item interface{}, exists bool, err error) {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+	item, exists = f.items[key]
+	return item, exists, nil
+}
+
+// IsClosed checks if the queue is closed
+func (f *FIFO) IsClosed() bool {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	return f.closed
+}
+
+// Pop waits until an item is ready and processes it. If multiple items are
+// ready, they are returned in the order in which they were added/updated.
+// The item is removed from the queue (and the store) before it is processed,
+// so if you don't successfully process it, it should be added back with
+// AddIfNotPresent(). process function is called under lock, so it is safe
+// update data structures in it that need to be in sync with the queue.
+func (f *FIFO) Pop(process PopProcessFunc) (interface{}, error) {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+	for {
+		for len(f.queue) == 0 {
+			// When the queue is empty, invocation of Pop() is blocked until new item is enqueued.
+			// When Close() is called, the f.closed is set and the condition is broadcasted.
+			// Which causes this loop to continue and return from the Pop().
+			if f.closed {
+				return nil, ErrFIFOClosed
+			}
+
+			f.cond.Wait()
+		}
+		id := f.queue[0]
+		f.queue = f.queue[1:]
+		if f.initialPopulationCount > 0 {
+			f.initialPopulationCount--
+		}
+		item, ok := f.items[id]
+		if !ok {
+			// Item may have been deleted subsequently.
+			continue
+		}
+		delete(f.items, id)
+		err := process(item)
+		if e, ok := err.(ErrRequeue); ok {
+			f.addIfNotPresent(id, item)
+			err = e.Err
+		}
+		return item, err
+	}
+}
+
+// Replace will delete the contents of 'f', using instead the given map.
+// 'f' takes ownership of the map, you should not reference the map again
+// after calling this function. f's queue is reset, too; upon return, it
+// will contain the items in the map, in no particular order.
+func (f *FIFO) Replace(list []interface{}, resourceVersion string) error {
+	items := make(map[string]interface{}, len(list))
+	for _, item := range list {
+		key, err := f.keyFunc(item)
+		if err != nil {
+			return KeyError{item, err}
+		}
+		items[key] = item
+	}
+
+	f.lock.Lock()
+	defer f.lock.Unlock()
+
+	if !f.populated {
+		f.populated = true
+		f.initialPopulationCount = len(items)
+	}
+
+	f.items = items
+	f.queue = f.queue[:0]
+	for id := range items {
+		f.queue = append(f.queue, id)
+	}
+	if len(f.queue) > 0 {
+		f.cond.Broadcast()
+	}
+	return nil
+}
+
+// Resync will ensure that every object in the Store has its key in the queue.
+// This should be a no-op, because that property is maintained by all operations.
+func (f *FIFO) Resync() error {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+
+	inQueue := sets.NewString()
+	for _, id := range f.queue {
+		inQueue.Insert(id)
+	}
+	for id := range f.items {
+		if !inQueue.Has(id) {
+			f.queue = append(f.queue, id)
+		}
+	}
+	if len(f.queue) > 0 {
+		f.cond.Broadcast()
+	}
+	return nil
+}
+
+// NewFIFO returns a Store which can be used to queue up items to
+// process.
+func NewFIFO(keyFunc KeyFunc) *FIFO {
+	f := &FIFO{
+		items:   map[string]interface{}{},
+		queue:   []string{},
+		keyFunc: keyFunc,
+	}
+	f.cond.L = &f.lock
+	return f
+}

vendor/k8s.io/client-go/tools/cache/heap.go

@@ -0,0 +1,322 @@
+/*
+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.
+*/
+
+// This file implements a heap data structure.
+
+package cache
+
+import (
+	"container/heap"
+	"fmt"
+	"sync"
+)
+
+const (
+	closedMsg = "heap is closed"
+)
+
+// LessFunc is used to compare two objects in the heap.
+type LessFunc func(interface{}, interface{}) bool
+
+type heapItem struct {
+	obj   interface{} // The object which is stored in the heap.
+	index int         // The index of the object's key in the Heap.queue.
+}
+
+type itemKeyValue struct {
+	key string
+	obj interface{}
+}
+
+// heapData is an internal struct that implements the standard heap interface
+// and keeps the data stored in the heap.
+type heapData struct {
+	// items is a map from key of the objects to the objects and their index.
+	// We depend on the property that items in the map are in the queue and vice versa.
+	items map[string]*heapItem
+	// queue implements a heap data structure and keeps the order of elements
+	// according to the heap invariant. The queue keeps the keys of objects stored
+	// in "items".
+	queue []string
+
+	// keyFunc is used to make the key used for queued item insertion and retrieval, and
+	// should be deterministic.
+	keyFunc KeyFunc
+	// lessFunc is used to compare two objects in the heap.
+	lessFunc LessFunc
+}
+
+var (
+	_ = heap.Interface(&heapData{}) // heapData is a standard heap
+)
+
+// Less compares two objects and returns true if the first one should go
+// in front of the second one in the heap.
+func (h *heapData) Less(i, j int) bool {
+	if i > len(h.queue) || j > len(h.queue) {
+		return false
+	}
+	itemi, ok := h.items[h.queue[i]]
+	if !ok {
+		return false
+	}
+	itemj, ok := h.items[h.queue[j]]
+	if !ok {
+		return false
+	}
+	return h.lessFunc(itemi.obj, itemj.obj)
+}
+
+// Len returns the number of items in the Heap.
+func (h *heapData) Len() int { return len(h.queue) }
+
+// Swap implements swapping of two elements in the heap. This is a part of standard
+// heap interface and should never be called directly.
+func (h *heapData) Swap(i, j int) {
+	h.queue[i], h.queue[j] = h.queue[j], h.queue[i]
+	item := h.items[h.queue[i]]
+	item.index = i
+	item = h.items[h.queue[j]]
+	item.index = j
+}
+
+// Push is supposed to be called by heap.Push only.
+func (h *heapData) Push(kv interface{}) {
+	keyValue := kv.(*itemKeyValue)
+	n := len(h.queue)
+	h.items[keyValue.key] = &heapItem{keyValue.obj, n}
+	h.queue = append(h.queue, keyValue.key)
+}
+
+// Pop is supposed to be called by heap.Pop only.
+func (h *heapData) Pop() interface{} {
+	key := h.queue[len(h.queue)-1]
+	h.queue = h.queue[0 : len(h.queue)-1]
+	item, ok := h.items[key]
+	if !ok {
+		// This is an error
+		return nil
+	}
+	delete(h.items, key)
+	return item.obj
+}
+
+// Heap is a thread-safe producer/consumer queue that implements a heap data structure.
+// It can be used to implement priority queues and similar data structures.
+type Heap struct {
+	lock sync.RWMutex
+	cond sync.Cond
+
+	// data stores objects and has a queue that keeps their ordering according
+	// to the heap invariant.
+	data *heapData
+
+	// closed indicates that the queue is closed.
+	// It is mainly used to let Pop() exit its control loop while waiting for an item.
+	closed bool
+}
+
+// Close the Heap and signals condition variables that may be waiting to pop
+// items from the heap.
+func (h *Heap) Close() {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	h.closed = true
+	h.cond.Broadcast()
+}
+
+// Add inserts an item, and puts it in the queue. The item is updated if it
+// already exists.
+func (h *Heap) Add(obj interface{}) error {
+	key, err := h.data.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	if h.closed {
+		return fmt.Errorf(closedMsg)
+	}
+	if _, exists := h.data.items[key]; exists {
+		h.data.items[key].obj = obj
+		heap.Fix(h.data, h.data.items[key].index)
+	} else {
+		h.addIfNotPresentLocked(key, obj)
+	}
+	h.cond.Broadcast()
+	return nil
+}
+
+// BulkAdd adds all the items in the list to the queue and then signals the condition
+// variable. It is useful when the caller would like to add all of the items
+// to the queue before consumer starts processing them.
+func (h *Heap) BulkAdd(list []interface{}) error {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	if h.closed {
+		return fmt.Errorf(closedMsg)
+	}
+	for _, obj := range list {
+		key, err := h.data.keyFunc(obj)
+		if err != nil {
+			return KeyError{obj, err}
+		}
+		if _, exists := h.data.items[key]; exists {
+			h.data.items[key].obj = obj
+			heap.Fix(h.data, h.data.items[key].index)
+		} else {
+			h.addIfNotPresentLocked(key, obj)
+		}
+	}
+	h.cond.Broadcast()
+	return nil
+}
+
+// AddIfNotPresent inserts an item, and puts it in the queue. If an item with
+// the key is present in the map, no changes is made to the item.
+//
+// This is useful in a single producer/consumer scenario so that the consumer can
+// safely retry items without contending with the producer and potentially enqueueing
+// stale items.
+func (h *Heap) AddIfNotPresent(obj interface{}) error {
+	id, err := h.data.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	if h.closed {
+		return fmt.Errorf(closedMsg)
+	}
+	h.addIfNotPresentLocked(id, obj)
+	h.cond.Broadcast()
+	return nil
+}
+
+// addIfNotPresentLocked assumes the lock is already held and adds the provided
+// item to the queue if it does not already exist.
+func (h *Heap) addIfNotPresentLocked(key string, obj interface{}) {
+	if _, exists := h.data.items[key]; exists {
+		return
+	}
+	heap.Push(h.data, &itemKeyValue{key, obj})
+}
+
+// Update is the same as Add in this implementation. When the item does not
+// exist, it is added.
+func (h *Heap) Update(obj interface{}) error {
+	return h.Add(obj)
+}
+
+// Delete removes an item.
+func (h *Heap) Delete(obj interface{}) error {
+	key, err := h.data.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	if item, ok := h.data.items[key]; ok {
+		heap.Remove(h.data, item.index)
+		return nil
+	}
+	return fmt.Errorf("object not found")
+}
+
+// Pop waits until an item is ready. If multiple items are
+// ready, they are returned in the order given by Heap.data.lessFunc.
+func (h *Heap) Pop() (interface{}, error) {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+	for len(h.data.queue) == 0 {
+		// When the queue is empty, invocation of Pop() is blocked until new item is enqueued.
+		// When Close() is called, the h.closed is set and the condition is broadcast,
+		// which causes this loop to continue and return from the Pop().
+		if h.closed {
+			return nil, fmt.Errorf("heap is closed")
+		}
+		h.cond.Wait()
+	}
+	obj := heap.Pop(h.data)
+	if obj == nil {
+		return nil, fmt.Errorf("object was removed from heap data")
+	}
+
+	return obj, nil
+}
+
+// List returns a list of all the items.
+func (h *Heap) List() []interface{} {
+	h.lock.RLock()
+	defer h.lock.RUnlock()
+	list := make([]interface{}, 0, len(h.data.items))
+	for _, item := range h.data.items {
+		list = append(list, item.obj)
+	}
+	return list
+}
+
+// ListKeys returns a list of all the keys of the objects currently in the Heap.
+func (h *Heap) ListKeys() []string {
+	h.lock.RLock()
+	defer h.lock.RUnlock()
+	list := make([]string, 0, len(h.data.items))
+	for key := range h.data.items {
+		list = append(list, key)
+	}
+	return list
+}
+
+// Get returns the requested item, or sets exists=false.
+func (h *Heap) Get(obj interface{}) (interface{}, bool, error) {
+	key, err := h.data.keyFunc(obj)
+	if err != nil {
+		return nil, false, KeyError{obj, err}
+	}
+	return h.GetByKey(key)
+}
+
+// GetByKey returns the requested item, or sets exists=false.
+func (h *Heap) GetByKey(key string) (interface{}, bool, error) {
+	h.lock.RLock()
+	defer h.lock.RUnlock()
+	item, exists := h.data.items[key]
+	if !exists {
+		return nil, false, nil
+	}
+	return item.obj, true, nil
+}
+
+// IsClosed returns true if the queue is closed.
+func (h *Heap) IsClosed() bool {
+	h.lock.RLock()
+	defer h.lock.RUnlock()
+	return h.closed
+}
+
+// NewHeap returns a Heap which can be used to queue up items to process.
+func NewHeap(keyFn KeyFunc, lessFn LessFunc) *Heap {
+	h := &Heap{
+		data: &heapData{
+			items:    map[string]*heapItem{},
+			queue:    []string{},
+			keyFunc:  keyFn,
+			lessFunc: lessFn,
+		},
+	}
+	h.cond.L = &h.lock
+	return h
+}

vendor/k8s.io/client-go/tools/cache/index.go

@@ -0,0 +1,101 @@
+/*
+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 cache
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// Indexer extends Store with multiple indices and restricts each
+// accumulator to simply hold the current object (and be empty after
+// Delete).
+//
+// There are three kinds of strings here:
+// 1. a storage key, as defined in the Store interface,
+// 2. a name of an index, and
+// 3. an "indexed value", which is produced by an IndexFunc and
+//    can be a field value or any other string computed from the object.
+type Indexer interface {
+	Store
+	// Index returns the stored objects whose set of indexed values
+	// intersects the set of indexed values of the given object, for
+	// the named index
+	Index(indexName string, obj interface{}) ([]interface{}, error)
+	// IndexKeys returns the storage keys of the stored objects whose
+	// set of indexed values for the named index includes the given
+	// indexed value
+	IndexKeys(indexName, indexedValue string) ([]string, error)
+	// ListIndexFuncValues returns all the indexed values of the given index
+	ListIndexFuncValues(indexName string) []string
+	// ByIndex returns the stored objects whose set of indexed values
+	// for the named index includes the given indexed value
+	ByIndex(indexName, indexedValue string) ([]interface{}, error)
+	// GetIndexer return the indexers
+	GetIndexers() Indexers
+
+	// AddIndexers adds more indexers to this store.  If you call this after you already have data
+	// in the store, the results are undefined.
+	AddIndexers(newIndexers Indexers) error
+}
+
+// IndexFunc knows how to compute the set of indexed values for an object.
+type IndexFunc func(obj interface{}) ([]string, error)
+
+// IndexFuncToKeyFuncAdapter adapts an indexFunc to a keyFunc.  This is only useful if your index function returns
+// unique values for every object.  This conversion can create errors when more than one key is found.  You
+// should prefer to make proper key and index functions.
+func IndexFuncToKeyFuncAdapter(indexFunc IndexFunc) KeyFunc {
+	return func(obj interface{}) (string, error) {
+		indexKeys, err := indexFunc(obj)
+		if err != nil {
+			return "", err
+		}
+		if len(indexKeys) > 1 {
+			return "", fmt.Errorf("too many keys: %v", indexKeys)
+		}
+		if len(indexKeys) == 0 {
+			return "", fmt.Errorf("unexpected empty indexKeys")
+		}
+		return indexKeys[0], nil
+	}
+}
+
+const (
+	// NamespaceIndex is the lookup name for the most common index function, which is to index by the namespace field.
+	NamespaceIndex string = "namespace"
+)
+
+// MetaNamespaceIndexFunc is a default index function that indexes based on an object's namespace
+func MetaNamespaceIndexFunc(obj interface{}) ([]string, error) {
+	meta, err := meta.Accessor(obj)
+	if err != nil {
+		return []string{""}, fmt.Errorf("object has no meta: %v", err)
+	}
+	return []string{meta.GetNamespace()}, nil
+}
+
+// Index maps the indexed value to a set of keys in the store that match on that value
+type Index map[string]sets.String
+
+// Indexers maps a name to an IndexFunc
+type Indexers map[string]IndexFunc
+
+// Indices maps a name to an Index
+type Indices map[string]Index

vendor/k8s.io/client-go/tools/cache/listers.go

@@ -0,0 +1,183 @@
+/*
+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 cache
+
+import (
+	"k8s.io/klog/v2"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// AppendFunc is used to add a matching item to whatever list the caller is using
+type AppendFunc func(interface{})
+
+// ListAll calls appendFn with each value retrieved from store which matches the selector.
+func ListAll(store Store, selector labels.Selector, appendFn AppendFunc) error {
+	selectAll := selector.Empty()
+	for _, m := range store.List() {
+		if selectAll {
+			// Avoid computing labels of the objects to speed up common flows
+			// of listing all objects.
+			appendFn(m)
+			continue
+		}
+		metadata, err := meta.Accessor(m)
+		if err != nil {
+			return err
+		}
+		if selector.Matches(labels.Set(metadata.GetLabels())) {
+			appendFn(m)
+		}
+	}
+	return nil
+}
+
+// ListAllByNamespace used to list items belongs to namespace from Indexer.
+func ListAllByNamespace(indexer Indexer, namespace string, selector labels.Selector, appendFn AppendFunc) error {
+	selectAll := selector.Empty()
+	if namespace == metav1.NamespaceAll {
+		for _, m := range indexer.List() {
+			if selectAll {
+				// Avoid computing labels of the objects to speed up common flows
+				// of listing all objects.
+				appendFn(m)
+				continue
+			}
+			metadata, err := meta.Accessor(m)
+			if err != nil {
+				return err
+			}
+			if selector.Matches(labels.Set(metadata.GetLabels())) {
+				appendFn(m)
+			}
+		}
+		return nil
+	}
+
+	items, err := indexer.Index(NamespaceIndex, &metav1.ObjectMeta{Namespace: namespace})
+	if err != nil {
+		// Ignore error; do slow search without index.
+		klog.Warningf("can not retrieve list of objects using index : %v", err)
+		for _, m := range indexer.List() {
+			metadata, err := meta.Accessor(m)
+			if err != nil {
+				return err
+			}
+			if metadata.GetNamespace() == namespace && selector.Matches(labels.Set(metadata.GetLabels())) {
+				appendFn(m)
+			}
+
+		}
+		return nil
+	}
+	for _, m := range items {
+		if selectAll {
+			// Avoid computing labels of the objects to speed up common flows
+			// of listing all objects.
+			appendFn(m)
+			continue
+		}
+		metadata, err := meta.Accessor(m)
+		if err != nil {
+			return err
+		}
+		if selector.Matches(labels.Set(metadata.GetLabels())) {
+			appendFn(m)
+		}
+	}
+
+	return nil
+}
+
+// GenericLister is a lister skin on a generic Indexer
+type GenericLister interface {
+	// List will return all objects across namespaces
+	List(selector labels.Selector) (ret []runtime.Object, err error)
+	// Get will attempt to retrieve assuming that name==key
+	Get(name string) (runtime.Object, error)
+	// ByNamespace will give you a GenericNamespaceLister for one namespace
+	ByNamespace(namespace string) GenericNamespaceLister
+}
+
+// GenericNamespaceLister is a lister skin on a generic Indexer
+type GenericNamespaceLister interface {
+	// List will return all objects in this namespace
+	List(selector labels.Selector) (ret []runtime.Object, err error)
+	// Get will attempt to retrieve by namespace and name
+	Get(name string) (runtime.Object, error)
+}
+
+// NewGenericLister creates a new instance for the genericLister.
+func NewGenericLister(indexer Indexer, resource schema.GroupResource) GenericLister {
+	return &genericLister{indexer: indexer, resource: resource}
+}
+
+type genericLister struct {
+	indexer  Indexer
+	resource schema.GroupResource
+}
+
+func (s *genericLister) List(selector labels.Selector) (ret []runtime.Object, err error) {
+	err = ListAll(s.indexer, selector, func(m interface{}) {
+		ret = append(ret, m.(runtime.Object))
+	})
+	return ret, err
+}
+
+func (s *genericLister) ByNamespace(namespace string) GenericNamespaceLister {
+	return &genericNamespaceLister{indexer: s.indexer, namespace: namespace, resource: s.resource}
+}
+
+func (s *genericLister) Get(name string) (runtime.Object, error) {
+	obj, exists, err := s.indexer.GetByKey(name)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		return nil, errors.NewNotFound(s.resource, name)
+	}
+	return obj.(runtime.Object), nil
+}
+
+type genericNamespaceLister struct {
+	indexer   Indexer
+	namespace string
+	resource  schema.GroupResource
+}
+
+func (s *genericNamespaceLister) List(selector labels.Selector) (ret []runtime.Object, err error) {
+	err = ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) {
+		ret = append(ret, m.(runtime.Object))
+	})
+	return ret, err
+}
+
+func (s *genericNamespaceLister) Get(name string) (runtime.Object, error) {
+	obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		return nil, errors.NewNotFound(s.resource, name)
+	}
+	return obj.(runtime.Object), nil
+}

vendor/k8s.io/client-go/tools/cache/listwatch.go

@@ -0,0 +1,112 @@
+/*
+Copyright 2015 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 cache
+
+import (
+	"context"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/watch"
+	restclient "k8s.io/client-go/rest"
+)
+
+// Lister is any object that knows how to perform an initial list.
+type Lister interface {
+	// List should return a list type object; the Items field will be extracted, and the
+	// ResourceVersion field will be used to start the watch in the right place.
+	List(options metav1.ListOptions) (runtime.Object, error)
+}
+
+// Watcher is any object that knows how to start a watch on a resource.
+type Watcher interface {
+	// Watch should begin a watch at the specified version.
+	Watch(options metav1.ListOptions) (watch.Interface, error)
+}
+
+// ListerWatcher is any object that knows how to perform an initial list and start a watch on a resource.
+type ListerWatcher interface {
+	Lister
+	Watcher
+}
+
+// ListFunc knows how to list resources
+type ListFunc func(options metav1.ListOptions) (runtime.Object, error)
+
+// WatchFunc knows how to watch resources
+type WatchFunc func(options metav1.ListOptions) (watch.Interface, error)
+
+// ListWatch knows how to list and watch a set of apiserver resources.  It satisfies the ListerWatcher interface.
+// It is a convenience function for users of NewReflector, etc.
+// ListFunc and WatchFunc must not be nil
+type ListWatch struct {
+	ListFunc  ListFunc
+	WatchFunc WatchFunc
+	// DisableChunking requests no chunking for this list watcher.
+	DisableChunking bool
+}
+
+// Getter interface knows how to access Get method from RESTClient.
+type Getter interface {
+	Get() *restclient.Request
+}
+
+// NewListWatchFromClient creates a new ListWatch from the specified client, resource, namespace and field selector.
+func NewListWatchFromClient(c Getter, resource string, namespace string, fieldSelector fields.Selector) *ListWatch {
+	optionsModifier := func(options *metav1.ListOptions) {
+		options.FieldSelector = fieldSelector.String()
+	}
+	return NewFilteredListWatchFromClient(c, resource, namespace, optionsModifier)
+}
+
+// NewFilteredListWatchFromClient creates a new ListWatch from the specified client, resource, namespace, and option modifier.
+// Option modifier is a function takes a ListOptions and modifies the consumed ListOptions. Provide customized modifier function
+// to apply modification to ListOptions with a field selector, a label selector, or any other desired options.
+func NewFilteredListWatchFromClient(c Getter, resource string, namespace string, optionsModifier func(options *metav1.ListOptions)) *ListWatch {
+	listFunc := func(options metav1.ListOptions) (runtime.Object, error) {
+		optionsModifier(&options)
+		return c.Get().
+			Namespace(namespace).
+			Resource(resource).
+			VersionedParams(&options, metav1.ParameterCodec).
+			Do(context.TODO()).
+			Get()
+	}
+	watchFunc := func(options metav1.ListOptions) (watch.Interface, error) {
+		options.Watch = true
+		optionsModifier(&options)
+		return c.Get().
+			Namespace(namespace).
+			Resource(resource).
+			VersionedParams(&options, metav1.ParameterCodec).
+			Watch(context.TODO())
+	}
+	return &ListWatch{ListFunc: listFunc, WatchFunc: watchFunc}
+}
+
+// List a set of apiserver resources
+func (lw *ListWatch) List(options metav1.ListOptions) (runtime.Object, error) {
+	// ListWatch is used in Reflector, which already supports pagination.
+	// Don't paginate here to avoid duplication.
+	return lw.ListFunc(options)
+}
+
+// Watch a set of apiserver resources
+func (lw *ListWatch) Watch(options metav1.ListOptions) (watch.Interface, error) {
+	return lw.WatchFunc(options)
+}

vendor/k8s.io/client-go/tools/cache/mutation_cache.go

@@ -0,0 +1,262 @@
+/*
+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 cache
+
+import (
+	"fmt"
+	"strconv"
+	"sync"
+	"time"
+
+	"k8s.io/klog/v2"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+	utilcache "k8s.io/apimachinery/pkg/util/cache"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// MutationCache is able to take the result of update operations and stores them in an LRU
+// that can be used to provide a more current view of a requested object.  It requires interpreting
+// resourceVersions for comparisons.
+// Implementations must be thread-safe.
+// TODO find a way to layer this into an informer/lister
+type MutationCache interface {
+	GetByKey(key string) (interface{}, bool, error)
+	ByIndex(indexName, indexKey string) ([]interface{}, error)
+	Mutation(interface{})
+}
+
+// ResourceVersionComparator is able to compare object versions.
+type ResourceVersionComparator interface {
+	CompareResourceVersion(lhs, rhs runtime.Object) int
+}
+
+// NewIntegerResourceVersionMutationCache returns a MutationCache that understands how to
+// deal with objects that have a resource version that:
+//
+//   - is an integer
+//   - increases when updated
+//   - is comparable across the same resource in a namespace
+//
+// Most backends will have these semantics. Indexer may be nil. ttl controls how long an item
+// remains in the mutation cache before it is removed.
+//
+// If includeAdds is true, objects in the mutation cache will be returned even if they don't exist
+// in the underlying store. This is only safe if your use of the cache can handle mutation entries
+// remaining in the cache for up to ttl when mutations and deletes occur very closely in time.
+func NewIntegerResourceVersionMutationCache(backingCache Store, indexer Indexer, ttl time.Duration, includeAdds bool) MutationCache {
+	return &mutationCache{
+		backingCache:  backingCache,
+		indexer:       indexer,
+		mutationCache: utilcache.NewLRUExpireCache(100),
+		comparator:    etcdObjectVersioner{},
+		ttl:           ttl,
+		includeAdds:   includeAdds,
+	}
+}
+
+// mutationCache doesn't guarantee that it returns values added via Mutation since they can page out and
+// since you can't distinguish between, "didn't observe create" and "was deleted after create",
+// if the key is missing from the backing cache, we always return it as missing
+type mutationCache struct {
+	lock          sync.Mutex
+	backingCache  Store
+	indexer       Indexer
+	mutationCache *utilcache.LRUExpireCache
+	includeAdds   bool
+	ttl           time.Duration
+
+	comparator ResourceVersionComparator
+}
+
+// GetByKey is never guaranteed to return back the value set in Mutation.  It could be paged out, it could
+// be older than another copy, the backingCache may be more recent or, you might have written twice into the same key.
+// You get a value that was valid at some snapshot of time and will always return the newer of backingCache and mutationCache.
+func (c *mutationCache) GetByKey(key string) (interface{}, bool, error) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	obj, exists, err := c.backingCache.GetByKey(key)
+	if err != nil {
+		return nil, false, err
+	}
+	if !exists {
+		if !c.includeAdds {
+			// we can't distinguish between, "didn't observe create" and "was deleted after create", so
+			// if the key is missing, we always return it as missing
+			return nil, false, nil
+		}
+		obj, exists = c.mutationCache.Get(key)
+		if !exists {
+			return nil, false, nil
+		}
+	}
+	objRuntime, ok := obj.(runtime.Object)
+	if !ok {
+		return obj, true, nil
+	}
+	return c.newerObject(key, objRuntime), true, nil
+}
+
+// ByIndex returns the newer objects that match the provided index and indexer key.
+// Will return an error if no indexer was provided.
+func (c *mutationCache) ByIndex(name string, indexKey string) ([]interface{}, error) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if c.indexer == nil {
+		return nil, fmt.Errorf("no indexer has been provided to the mutation cache")
+	}
+	keys, err := c.indexer.IndexKeys(name, indexKey)
+	if err != nil {
+		return nil, err
+	}
+	var items []interface{}
+	keySet := sets.NewString()
+	for _, key := range keys {
+		keySet.Insert(key)
+		obj, exists, err := c.indexer.GetByKey(key)
+		if err != nil {
+			return nil, err
+		}
+		if !exists {
+			continue
+		}
+		if objRuntime, ok := obj.(runtime.Object); ok {
+			items = append(items, c.newerObject(key, objRuntime))
+		} else {
+			items = append(items, obj)
+		}
+	}
+
+	if c.includeAdds {
+		fn := c.indexer.GetIndexers()[name]
+		// Keys() is returned oldest to newest, so full traversal does not alter the LRU behavior
+		for _, key := range c.mutationCache.Keys() {
+			updated, ok := c.mutationCache.Get(key)
+			if !ok {
+				continue
+			}
+			if keySet.Has(key.(string)) {
+				continue
+			}
+			elements, err := fn(updated)
+			if err != nil {
+				klog.V(4).Infof("Unable to calculate an index entry for mutation cache entry %s: %v", key, err)
+				continue
+			}
+			for _, inIndex := range elements {
+				if inIndex != indexKey {
+					continue
+				}
+				items = append(items, updated)
+				break
+			}
+		}
+	}
+
+	return items, nil
+}
+
+// newerObject checks the mutation cache for a newer object and returns one if found. If the
+// mutated object is older than the backing object, it is removed from the  Must be
+// called while the lock is held.
+func (c *mutationCache) newerObject(key string, backing runtime.Object) runtime.Object {
+	mutatedObj, exists := c.mutationCache.Get(key)
+	if !exists {
+		return backing
+	}
+	mutatedObjRuntime, ok := mutatedObj.(runtime.Object)
+	if !ok {
+		return backing
+	}
+	if c.comparator.CompareResourceVersion(backing, mutatedObjRuntime) >= 0 {
+		c.mutationCache.Remove(key)
+		return backing
+	}
+	return mutatedObjRuntime
+}
+
+// Mutation adds a change to the cache that can be returned in GetByKey if it is newer than the backingCache
+// copy.  If you call Mutation twice with the same object on different threads, one will win, but its not defined
+// which one.  This doesn't affect correctness, since the GetByKey guaranteed of "later of these two caches" is
+// preserved, but you may not get the version of the object you want.  The object you get is only guaranteed to
+// "one that was valid at some point in time", not "the one that I want".
+func (c *mutationCache) Mutation(obj interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	key, err := DeletionHandlingMetaNamespaceKeyFunc(obj)
+	if err != nil {
+		// this is a "nice to have", so failures shouldn't do anything weird
+		utilruntime.HandleError(err)
+		return
+	}
+
+	if objRuntime, ok := obj.(runtime.Object); ok {
+		if mutatedObj, exists := c.mutationCache.Get(key); exists {
+			if mutatedObjRuntime, ok := mutatedObj.(runtime.Object); ok {
+				if c.comparator.CompareResourceVersion(objRuntime, mutatedObjRuntime) < 0 {
+					return
+				}
+			}
+		}
+	}
+	c.mutationCache.Add(key, obj, c.ttl)
+}
+
+// etcdObjectVersioner implements versioning and extracting etcd node information
+// for objects that have an embedded ObjectMeta or ListMeta field.
+type etcdObjectVersioner struct{}
+
+// ObjectResourceVersion implements Versioner
+func (a etcdObjectVersioner) ObjectResourceVersion(obj runtime.Object) (uint64, error) {
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return 0, err
+	}
+	version := accessor.GetResourceVersion()
+	if len(version) == 0 {
+		return 0, nil
+	}
+	return strconv.ParseUint(version, 10, 64)
+}
+
+// CompareResourceVersion compares etcd resource versions.  Outside this API they are all strings,
+// but etcd resource versions are special, they're actually ints, so we can easily compare them.
+func (a etcdObjectVersioner) CompareResourceVersion(lhs, rhs runtime.Object) int {
+	lhsVersion, err := a.ObjectResourceVersion(lhs)
+	if err != nil {
+		// coder error
+		panic(err)
+	}
+	rhsVersion, err := a.ObjectResourceVersion(rhs)
+	if err != nil {
+		// coder error
+		panic(err)
+	}
+
+	if lhsVersion == rhsVersion {
+		return 0
+	}
+	if lhsVersion < rhsVersion {
+		return -1
+	}
+
+	return 1
+}

vendor/k8s.io/client-go/tools/cache/mutation_detector.go

@@ -0,0 +1,166 @@
+/*
+Copyright 2016 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 cache
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"strconv"
+	"sync"
+	"time"
+
+	"k8s.io/klog/v2"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/diff"
+)
+
+var mutationDetectionEnabled = false
+
+func init() {
+	mutationDetectionEnabled, _ = strconv.ParseBool(os.Getenv("KUBE_CACHE_MUTATION_DETECTOR"))
+}
+
+// MutationDetector is able to monitor objects for mutation within a limited window of time
+type MutationDetector interface {
+	// AddObject adds the given object to the set being monitored for a while from now
+	AddObject(obj interface{})
+
+	// Run starts the monitoring and does not return until the monitoring is stopped.
+	Run(stopCh <-chan struct{})
+}
+
+// NewCacheMutationDetector creates a new instance for the defaultCacheMutationDetector.
+func NewCacheMutationDetector(name string) MutationDetector {
+	if !mutationDetectionEnabled {
+		return dummyMutationDetector{}
+	}
+	klog.Warningln("Mutation detector is enabled, this will result in memory leakage.")
+	return &defaultCacheMutationDetector{name: name, period: 1 * time.Second, retainDuration: 2 * time.Minute}
+}
+
+type dummyMutationDetector struct{}
+
+func (dummyMutationDetector) Run(stopCh <-chan struct{}) {
+}
+func (dummyMutationDetector) AddObject(obj interface{}) {
+}
+
+// defaultCacheMutationDetector gives a way to detect if a cached object has been mutated
+// It has a list of cached objects and their copies.  I haven't thought of a way
+// to see WHO is mutating it, just that it's getting mutated.
+type defaultCacheMutationDetector struct {
+	name   string
+	period time.Duration
+
+	// compareLock ensures only a single call to CompareObjects runs at a time
+	compareObjectsLock sync.Mutex
+
+	// addLock guards addedObjs between AddObject and CompareObjects
+	addedObjsLock sync.Mutex
+	addedObjs     []cacheObj
+
+	cachedObjs []cacheObj
+
+	retainDuration     time.Duration
+	lastRotated        time.Time
+	retainedCachedObjs []cacheObj
+
+	// failureFunc is injectable for unit testing.  If you don't have it, the process will panic.
+	// This panic is intentional, since turning on this detection indicates you want a strong
+	// failure signal.  This failure is effectively a p0 bug and you can't trust process results
+	// after a mutation anyway.
+	failureFunc func(message string)
+}
+
+// cacheObj holds the actual object and a copy
+type cacheObj struct {
+	cached interface{}
+	copied interface{}
+}
+
+func (d *defaultCacheMutationDetector) Run(stopCh <-chan struct{}) {
+	// we DON'T want protection from panics.  If we're running this code, we want to die
+	for {
+		if d.lastRotated.IsZero() {
+			d.lastRotated = time.Now()
+		} else if time.Since(d.lastRotated) > d.retainDuration {
+			d.retainedCachedObjs = d.cachedObjs
+			d.cachedObjs = nil
+			d.lastRotated = time.Now()
+		}
+
+		d.CompareObjects()
+
+		select {
+		case <-stopCh:
+			return
+		case <-time.After(d.period):
+		}
+	}
+}
+
+// AddObject makes a deep copy of the object for later comparison.  It only works on runtime.Object
+// but that covers the vast majority of our cached objects
+func (d *defaultCacheMutationDetector) AddObject(obj interface{}) {
+	if _, ok := obj.(DeletedFinalStateUnknown); ok {
+		return
+	}
+	if obj, ok := obj.(runtime.Object); ok {
+		copiedObj := obj.DeepCopyObject()
+
+		d.addedObjsLock.Lock()
+		defer d.addedObjsLock.Unlock()
+		d.addedObjs = append(d.addedObjs, cacheObj{cached: obj, copied: copiedObj})
+	}
+}
+
+func (d *defaultCacheMutationDetector) CompareObjects() {
+	d.compareObjectsLock.Lock()
+	defer d.compareObjectsLock.Unlock()
+
+	// move addedObjs into cachedObjs under lock
+	// this keeps the critical section small to avoid blocking AddObject while we compare cachedObjs
+	d.addedObjsLock.Lock()
+	d.cachedObjs = append(d.cachedObjs, d.addedObjs...)
+	d.addedObjs = nil
+	d.addedObjsLock.Unlock()
+
+	altered := false
+	for i, obj := range d.cachedObjs {
+		if !reflect.DeepEqual(obj.cached, obj.copied) {
+			fmt.Printf("CACHE %s[%d] ALTERED!\n%v\n", d.name, i, diff.ObjectGoPrintSideBySide(obj.cached, obj.copied))
+			altered = true
+		}
+	}
+	for i, obj := range d.retainedCachedObjs {
+		if !reflect.DeepEqual(obj.cached, obj.copied) {
+			fmt.Printf("CACHE %s[%d] ALTERED!\n%v\n", d.name, i, diff.ObjectGoPrintSideBySide(obj.cached, obj.copied))
+			altered = true
+		}
+	}
+
+	if altered {
+		msg := fmt.Sprintf("cache %s modified", d.name)
+		if d.failureFunc != nil {
+			d.failureFunc(msg)
+			return
+		}
+		panic(msg)
+	}
+}

vendor/k8s.io/client-go/tools/cache/reflector.go

@@ -0,0 +1,616 @@
+/*
+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 cache
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"reflect"
+	"sync"
+	"time"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/naming"
+	utilnet "k8s.io/apimachinery/pkg/util/net"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/tools/pager"
+	"k8s.io/klog/v2"
+	"k8s.io/utils/clock"
+	"k8s.io/utils/trace"
+)
+
+const defaultExpectedTypeName = "<unspecified>"
+
+// Reflector watches a specified resource and causes all changes to be reflected in the given store.
+type Reflector struct {
+	// name identifies this reflector. By default it will be a file:line if possible.
+	name string
+
+	// The name of the type we expect to place in the store. The name
+	// will be the stringification of expectedGVK if provided, and the
+	// stringification of expectedType otherwise. It is for display
+	// only, and should not be used for parsing or comparison.
+	expectedTypeName string
+	// An example object of the type we expect to place in the store.
+	// Only the type needs to be right, except that when that is
+	// `unstructured.Unstructured` the object's `"apiVersion"` and
+	// `"kind"` must also be right.
+	expectedType reflect.Type
+	// The GVK of the object we expect to place in the store if unstructured.
+	expectedGVK *schema.GroupVersionKind
+	// The destination to sync up with the watch source
+	store Store
+	// listerWatcher is used to perform lists and watches.
+	listerWatcher ListerWatcher
+
+	// backoff manages backoff of ListWatch
+	backoffManager wait.BackoffManager
+	// initConnBackoffManager manages backoff the initial connection with the Watch call of ListAndWatch.
+	initConnBackoffManager wait.BackoffManager
+
+	resyncPeriod time.Duration
+	// ShouldResync is invoked periodically and whenever it returns `true` the Store's Resync operation is invoked
+	ShouldResync func() bool
+	// clock allows tests to manipulate time
+	clock clock.Clock
+	// paginatedResult defines whether pagination should be forced for list calls.
+	// It is set based on the result of the initial list call.
+	paginatedResult bool
+	// lastSyncResourceVersion is the resource version token last
+	// observed when doing a sync with the underlying store
+	// it is thread safe, but not synchronized with the underlying store
+	lastSyncResourceVersion string
+	// isLastSyncResourceVersionUnavailable is true if the previous list or watch request with
+	// lastSyncResourceVersion failed with an "expired" or "too large resource version" error.
+	isLastSyncResourceVersionUnavailable bool
+	// lastSyncResourceVersionMutex guards read/write access to lastSyncResourceVersion
+	lastSyncResourceVersionMutex sync.RWMutex
+	// WatchListPageSize is the requested chunk size of initial and resync watch lists.
+	// If unset, for consistent reads (RV="") or reads that opt-into arbitrarily old data
+	// (RV="0") it will default to pager.PageSize, for the rest (RV != "" && RV != "0")
+	// it will turn off pagination to allow serving them from watch cache.
+	// NOTE: It should be used carefully as paginated lists are always served directly from
+	// etcd, which is significantly less efficient and may lead to serious performance and
+	// scalability problems.
+	WatchListPageSize int64
+	// Called whenever the ListAndWatch drops the connection with an error.
+	watchErrorHandler WatchErrorHandler
+}
+
+// ResourceVersionUpdater is an interface that allows store implementation to
+// track the current resource version of the reflector. This is especially
+// important if storage bookmarks are enabled.
+type ResourceVersionUpdater interface {
+	// UpdateResourceVersion is called each time current resource version of the reflector
+	// is updated.
+	UpdateResourceVersion(resourceVersion string)
+}
+
+// The WatchErrorHandler is called whenever ListAndWatch drops the
+// connection with an error. After calling this handler, the informer
+// will backoff and retry.
+//
+// The default implementation looks at the error type and tries to log
+// the error message at an appropriate level.
+//
+// Implementations of this handler may display the error message in other
+// ways. Implementations should return quickly - any expensive processing
+// should be offloaded.
+type WatchErrorHandler func(r *Reflector, err error)
+
+// DefaultWatchErrorHandler is the default implementation of WatchErrorHandler
+func DefaultWatchErrorHandler(r *Reflector, err error) {
+	switch {
+	case isExpiredError(err):
+		// Don't set LastSyncResourceVersionUnavailable - LIST call with ResourceVersion=RV already
+		// has a semantic that it returns data at least as fresh as provided RV.
+		// So first try to LIST with setting RV to resource version of last observed object.
+		klog.V(4).Infof("%s: watch of %v closed with: %v", r.name, r.expectedTypeName, err)
+	case err == io.EOF:
+		// watch closed normally
+	case err == io.ErrUnexpectedEOF:
+		klog.V(1).Infof("%s: Watch for %v closed with unexpected EOF: %v", r.name, r.expectedTypeName, err)
+	default:
+		utilruntime.HandleError(fmt.Errorf("%s: Failed to watch %v: %v", r.name, r.expectedTypeName, err))
+	}
+}
+
+var (
+	// We try to spread the load on apiserver by setting timeouts for
+	// watch requests - it is random in [minWatchTimeout, 2*minWatchTimeout].
+	minWatchTimeout = 5 * time.Minute
+)
+
+// NewNamespaceKeyedIndexerAndReflector creates an Indexer and a Reflector
+// The indexer is configured to key on namespace
+func NewNamespaceKeyedIndexerAndReflector(lw ListerWatcher, expectedType interface{}, resyncPeriod time.Duration) (indexer Indexer, reflector *Reflector) {
+	indexer = NewIndexer(MetaNamespaceKeyFunc, Indexers{NamespaceIndex: MetaNamespaceIndexFunc})
+	reflector = NewReflector(lw, expectedType, indexer, resyncPeriod)
+	return indexer, reflector
+}
+
+// NewReflector creates a new Reflector object which will keep the
+// given store up to date with the server's contents for the given
+// resource. Reflector promises to only put things in the store that
+// have the type of expectedType, unless expectedType is nil. If
+// resyncPeriod is non-zero, then the reflector will periodically
+// consult its ShouldResync function to determine whether to invoke
+// the Store's Resync operation; `ShouldResync==nil` means always
+// "yes".  This enables you to use reflectors to periodically process
+// everything as well as incrementally processing the things that
+// change.
+func NewReflector(lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
+	return NewNamedReflector(naming.GetNameFromCallsite(internalPackages...), lw, expectedType, store, resyncPeriod)
+}
+
+// NewNamedReflector same as NewReflector, but with a specified name for logging
+func NewNamedReflector(name string, lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
+	realClock := &clock.RealClock{}
+	r := &Reflector{
+		name:          name,
+		listerWatcher: lw,
+		store:         store,
+		// We used to make the call every 1sec (1 QPS), the goal here is to achieve ~98% traffic reduction when
+		// API server is not healthy. With these parameters, backoff will stop at [30,60) sec interval which is
+		// 0.22 QPS. If we don't backoff for 2min, assume API server is healthy and we reset the backoff.
+		backoffManager:         wait.NewExponentialBackoffManager(800*time.Millisecond, 30*time.Second, 2*time.Minute, 2.0, 1.0, realClock),
+		initConnBackoffManager: wait.NewExponentialBackoffManager(800*time.Millisecond, 30*time.Second, 2*time.Minute, 2.0, 1.0, realClock),
+		resyncPeriod:           resyncPeriod,
+		clock:                  realClock,
+		watchErrorHandler:      WatchErrorHandler(DefaultWatchErrorHandler),
+	}
+	r.setExpectedType(expectedType)
+	return r
+}
+
+func (r *Reflector) setExpectedType(expectedType interface{}) {
+	r.expectedType = reflect.TypeOf(expectedType)
+	if r.expectedType == nil {
+		r.expectedTypeName = defaultExpectedTypeName
+		return
+	}
+
+	r.expectedTypeName = r.expectedType.String()
+
+	if obj, ok := expectedType.(*unstructured.Unstructured); ok {
+		// Use gvk to check that watch event objects are of the desired type.
+		gvk := obj.GroupVersionKind()
+		if gvk.Empty() {
+			klog.V(4).Infof("Reflector from %s configured with expectedType of *unstructured.Unstructured with empty GroupVersionKind.", r.name)
+			return
+		}
+		r.expectedGVK = &gvk
+		r.expectedTypeName = gvk.String()
+	}
+}
+
+// internalPackages are packages that ignored when creating a default reflector name. These packages are in the common
+// call chains to NewReflector, so they'd be low entropy names for reflectors
+var internalPackages = []string{"client-go/tools/cache/"}
+
+// Run repeatedly uses the reflector's ListAndWatch to fetch all the
+// objects and subsequent deltas.
+// Run will exit when stopCh is closed.
+func (r *Reflector) Run(stopCh <-chan struct{}) {
+	klog.V(3).Infof("Starting reflector %s (%s) from %s", r.expectedTypeName, r.resyncPeriod, r.name)
+	wait.BackoffUntil(func() {
+		if err := r.ListAndWatch(stopCh); err != nil {
+			r.watchErrorHandler(r, err)
+		}
+	}, r.backoffManager, true, stopCh)
+	klog.V(3).Infof("Stopping reflector %s (%s) from %s", r.expectedTypeName, r.resyncPeriod, r.name)
+}
+
+var (
+	// nothing will ever be sent down this channel
+	neverExitWatch <-chan time.Time = make(chan time.Time)
+
+	// Used to indicate that watching stopped because of a signal from the stop
+	// channel passed in from a client of the reflector.
+	errorStopRequested = errors.New("stop requested")
+)
+
+// resyncChan returns a channel which will receive something when a resync is
+// required, and a cleanup function.
+func (r *Reflector) resyncChan() (<-chan time.Time, func() bool) {
+	if r.resyncPeriod == 0 {
+		return neverExitWatch, func() bool { return false }
+	}
+	// The cleanup function is required: imagine the scenario where watches
+	// always fail so we end up listing frequently. Then, if we don't
+	// manually stop the timer, we could end up with many timers active
+	// concurrently.
+	t := r.clock.NewTimer(r.resyncPeriod)
+	return t.C(), t.Stop
+}
+
+// ListAndWatch first lists all items and get the resource version at the moment of call,
+// and then use the resource version to watch.
+// It returns error if ListAndWatch didn't even try to initialize watch.
+func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
+	klog.V(3).Infof("Listing and watching %v from %s", r.expectedTypeName, r.name)
+	var resourceVersion string
+
+	options := metav1.ListOptions{ResourceVersion: r.relistResourceVersion()}
+
+	if err := func() error {
+		initTrace := trace.New("Reflector ListAndWatch", trace.Field{Key: "name", Value: r.name})
+		defer initTrace.LogIfLong(10 * time.Second)
+		var list runtime.Object
+		var paginatedResult bool
+		var err error
+		listCh := make(chan struct{}, 1)
+		panicCh := make(chan interface{}, 1)
+		go func() {
+			defer func() {
+				if r := recover(); r != nil {
+					panicCh <- r
+				}
+			}()
+			// Attempt to gather list in chunks, if supported by listerWatcher, if not, the first
+			// list request will return the full response.
+			pager := pager.New(pager.SimplePageFunc(func(opts metav1.ListOptions) (runtime.Object, error) {
+				return r.listerWatcher.List(opts)
+			}))
+			switch {
+			case r.WatchListPageSize != 0:
+				pager.PageSize = r.WatchListPageSize
+			case r.paginatedResult:
+				// We got a paginated result initially. Assume this resource and server honor
+				// paging requests (i.e. watch cache is probably disabled) and leave the default
+				// pager size set.
+			case options.ResourceVersion != "" && options.ResourceVersion != "0":
+				// User didn't explicitly request pagination.
+				//
+				// With ResourceVersion != "", we have a possibility to list from watch cache,
+				// but we do that (for ResourceVersion != "0") only if Limit is unset.
+				// To avoid thundering herd on etcd (e.g. on master upgrades), we explicitly
+				// switch off pagination to force listing from watch cache (if enabled).
+				// With the existing semantic of RV (result is at least as fresh as provided RV),
+				// this is correct and doesn't lead to going back in time.
+				//
+				// We also don't turn off pagination for ResourceVersion="0", since watch cache
+				// is ignoring Limit in that case anyway, and if watch cache is not enabled
+				// we don't introduce regression.
+				pager.PageSize = 0
+			}
+
+			list, paginatedResult, err = pager.List(context.Background(), options)
+			if isExpiredError(err) || isTooLargeResourceVersionError(err) {
+				r.setIsLastSyncResourceVersionUnavailable(true)
+				// Retry immediately if the resource version used to list is unavailable.
+				// The pager already falls back to full list if paginated list calls fail due to an "Expired" error on
+				// continuation pages, but the pager might not be enabled, the full list might fail because the
+				// resource version it is listing at is expired or the cache may not yet be synced to the provided
+				// resource version. So we need to fallback to resourceVersion="" in all to recover and ensure
+				// the reflector makes forward progress.
+				list, paginatedResult, err = pager.List(context.Background(), metav1.ListOptions{ResourceVersion: r.relistResourceVersion()})
+			}
+			close(listCh)
+		}()
+		select {
+		case <-stopCh:
+			return nil
+		case r := <-panicCh:
+			panic(r)
+		case <-listCh:
+		}
+		initTrace.Step("Objects listed", trace.Field{Key: "error", Value: err})
+		if err != nil {
+			klog.Warningf("%s: failed to list %v: %v", r.name, r.expectedTypeName, err)
+			return fmt.Errorf("failed to list %v: %v", r.expectedTypeName, err)
+		}
+
+		// We check if the list was paginated and if so set the paginatedResult based on that.
+		// However, we want to do that only for the initial list (which is the only case
+		// when we set ResourceVersion="0"). The reasoning behind it is that later, in some
+		// situations we may force listing directly from etcd (by setting ResourceVersion="")
+		// which will return paginated result, even if watch cache is enabled. However, in
+		// that case, we still want to prefer sending requests to watch cache if possible.
+		//
+		// Paginated result returned for request with ResourceVersion="0" mean that watch
+		// cache is disabled and there are a lot of objects of a given type. In such case,
+		// there is no need to prefer listing from watch cache.
+		if options.ResourceVersion == "0" && paginatedResult {
+			r.paginatedResult = true
+		}
+
+		r.setIsLastSyncResourceVersionUnavailable(false) // list was successful
+		listMetaInterface, err := meta.ListAccessor(list)
+		if err != nil {
+			return fmt.Errorf("unable to understand list result %#v: %v", list, err)
+		}
+		resourceVersion = listMetaInterface.GetResourceVersion()
+		initTrace.Step("Resource version extracted")
+		items, err := meta.ExtractList(list)
+		if err != nil {
+			return fmt.Errorf("unable to understand list result %#v (%v)", list, err)
+		}
+		initTrace.Step("Objects extracted")
+		if err := r.syncWith(items, resourceVersion); err != nil {
+			return fmt.Errorf("unable to sync list result: %v", err)
+		}
+		initTrace.Step("SyncWith done")
+		r.setLastSyncResourceVersion(resourceVersion)
+		initTrace.Step("Resource version updated")
+		return nil
+	}(); err != nil {
+		return err
+	}
+
+	resyncerrc := make(chan error, 1)
+	cancelCh := make(chan struct{})
+	defer close(cancelCh)
+	go func() {
+		resyncCh, cleanup := r.resyncChan()
+		defer func() {
+			cleanup() // Call the last one written into cleanup
+		}()
+		for {
+			select {
+			case <-resyncCh:
+			case <-stopCh:
+				return
+			case <-cancelCh:
+				return
+			}
+			if r.ShouldResync == nil || r.ShouldResync() {
+				klog.V(4).Infof("%s: forcing resync", r.name)
+				if err := r.store.Resync(); err != nil {
+					resyncerrc <- err
+					return
+				}
+			}
+			cleanup()
+			resyncCh, cleanup = r.resyncChan()
+		}
+	}()
+
+	for {
+		// give the stopCh a chance to stop the loop, even in case of continue statements further down on errors
+		select {
+		case <-stopCh:
+			return nil
+		default:
+		}
+
+		timeoutSeconds := int64(minWatchTimeout.Seconds() * (rand.Float64() + 1.0))
+		options = metav1.ListOptions{
+			ResourceVersion: resourceVersion,
+			// We want to avoid situations of hanging watchers. Stop any watchers that do not
+			// receive any events within the timeout window.
+			TimeoutSeconds: &timeoutSeconds,
+			// To reduce load on kube-apiserver on watch restarts, you may enable watch bookmarks.
+			// Reflector doesn't assume bookmarks are returned at all (if the server do not support
+			// watch bookmarks, it will ignore this field).
+			AllowWatchBookmarks: true,
+		}
+
+		// start the clock before sending the request, since some proxies won't flush headers until after the first watch event is sent
+		start := r.clock.Now()
+		w, err := r.listerWatcher.Watch(options)
+		if err != nil {
+			// If this is "connection refused" error, it means that most likely apiserver is not responsive.
+			// It doesn't make sense to re-list all objects because most likely we will be able to restart
+			// watch where we ended.
+			// If that's the case begin exponentially backing off and resend watch request.
+			// Do the same for "429" errors.
+			if utilnet.IsConnectionRefused(err) || apierrors.IsTooManyRequests(err) {
+				<-r.initConnBackoffManager.Backoff().C()
+				continue
+			}
+			return err
+		}
+
+		if err := r.watchHandler(start, w, &resourceVersion, resyncerrc, stopCh); err != nil {
+			if err != errorStopRequested {
+				switch {
+				case isExpiredError(err):
+					// Don't set LastSyncResourceVersionUnavailable - LIST call with ResourceVersion=RV already
+					// has a semantic that it returns data at least as fresh as provided RV.
+					// So first try to LIST with setting RV to resource version of last observed object.
+					klog.V(4).Infof("%s: watch of %v closed with: %v", r.name, r.expectedTypeName, err)
+				case apierrors.IsTooManyRequests(err):
+					klog.V(2).Infof("%s: watch of %v returned 429 - backing off", r.name, r.expectedTypeName)
+					<-r.initConnBackoffManager.Backoff().C()
+					continue
+				default:
+					klog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedTypeName, err)
+				}
+			}
+			return nil
+		}
+	}
+}
+
+// syncWith replaces the store's items with the given list.
+func (r *Reflector) syncWith(items []runtime.Object, resourceVersion string) error {
+	found := make([]interface{}, 0, len(items))
+	for _, item := range items {
+		found = append(found, item)
+	}
+	return r.store.Replace(found, resourceVersion)
+}
+
+// watchHandler watches w and keeps *resourceVersion up to date.
+func (r *Reflector) watchHandler(start time.Time, w watch.Interface, resourceVersion *string, errc chan error, stopCh <-chan struct{}) error {
+	eventCount := 0
+
+	// Stopping the watcher should be idempotent and if we return from this function there's no way
+	// we're coming back in with the same watch interface.
+	defer w.Stop()
+
+loop:
+	for {
+		select {
+		case <-stopCh:
+			return errorStopRequested
+		case err := <-errc:
+			return err
+		case event, ok := <-w.ResultChan():
+			if !ok {
+				break loop
+			}
+			if event.Type == watch.Error {
+				return apierrors.FromObject(event.Object)
+			}
+			if r.expectedType != nil {
+				if e, a := r.expectedType, reflect.TypeOf(event.Object); e != a {
+					utilruntime.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a))
+					continue
+				}
+			}
+			if r.expectedGVK != nil {
+				if e, a := *r.expectedGVK, event.Object.GetObjectKind().GroupVersionKind(); e != a {
+					utilruntime.HandleError(fmt.Errorf("%s: expected gvk %v, but watch event object had gvk %v", r.name, e, a))
+					continue
+				}
+			}
+			meta, err := meta.Accessor(event.Object)
+			if err != nil {
+				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
+				continue
+			}
+			newResourceVersion := meta.GetResourceVersion()
+			switch event.Type {
+			case watch.Added:
+				err := r.store.Add(event.Object)
+				if err != nil {
+					utilruntime.HandleError(fmt.Errorf("%s: unable to add watch event object (%#v) to store: %v", r.name, event.Object, err))
+				}
+			case watch.Modified:
+				err := r.store.Update(event.Object)
+				if err != nil {
+					utilruntime.HandleError(fmt.Errorf("%s: unable to update watch event object (%#v) to store: %v", r.name, event.Object, err))
+				}
+			case watch.Deleted:
+				// TODO: Will any consumers need access to the "last known
+				// state", which is passed in event.Object? If so, may need
+				// to change this.
+				err := r.store.Delete(event.Object)
+				if err != nil {
+					utilruntime.HandleError(fmt.Errorf("%s: unable to delete watch event object (%#v) from store: %v", r.name, event.Object, err))
+				}
+			case watch.Bookmark:
+				// A `Bookmark` means watch has synced here, just update the resourceVersion
+			default:
+				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
+			}
+			*resourceVersion = newResourceVersion
+			r.setLastSyncResourceVersion(newResourceVersion)
+			if rvu, ok := r.store.(ResourceVersionUpdater); ok {
+				rvu.UpdateResourceVersion(newResourceVersion)
+			}
+			eventCount++
+		}
+	}
+
+	watchDuration := r.clock.Since(start)
+	if watchDuration < 1*time.Second && eventCount == 0 {
+		return fmt.Errorf("very short watch: %s: Unexpected watch close - watch lasted less than a second and no items received", r.name)
+	}
+	klog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedTypeName, eventCount)
+	return nil
+}
+
+// LastSyncResourceVersion is the resource version observed when last sync with the underlying store
+// The value returned is not synchronized with access to the underlying store and is not thread-safe
+func (r *Reflector) LastSyncResourceVersion() string {
+	r.lastSyncResourceVersionMutex.RLock()
+	defer r.lastSyncResourceVersionMutex.RUnlock()
+	return r.lastSyncResourceVersion
+}
+
+func (r *Reflector) setLastSyncResourceVersion(v string) {
+	r.lastSyncResourceVersionMutex.Lock()
+	defer r.lastSyncResourceVersionMutex.Unlock()
+	r.lastSyncResourceVersion = v
+}
+
+// relistResourceVersion determines the resource version the reflector should list or relist from.
+// Returns either the lastSyncResourceVersion so that this reflector will relist with a resource
+// versions no older than has already been observed in relist results or watch events, or, if the last relist resulted
+// in an HTTP 410 (Gone) status code, returns "" so that the relist will use the latest resource version available in
+// etcd via a quorum read.
+func (r *Reflector) relistResourceVersion() string {
+	r.lastSyncResourceVersionMutex.RLock()
+	defer r.lastSyncResourceVersionMutex.RUnlock()
+
+	if r.isLastSyncResourceVersionUnavailable {
+		// Since this reflector makes paginated list requests, and all paginated list requests skip the watch cache
+		// if the lastSyncResourceVersion is unavailable, we set ResourceVersion="" and list again to re-establish reflector
+		// to the latest available ResourceVersion, using a consistent read from etcd.
+		return ""
+	}
+	if r.lastSyncResourceVersion == "" {
+		// For performance reasons, initial list performed by reflector uses "0" as resource version to allow it to
+		// be served from the watch cache if it is enabled.
+		return "0"
+	}
+	return r.lastSyncResourceVersion
+}
+
+// setIsLastSyncResourceVersionUnavailable sets if the last list or watch request with lastSyncResourceVersion returned
+// "expired" or "too large resource version" error.
+func (r *Reflector) setIsLastSyncResourceVersionUnavailable(isUnavailable bool) {
+	r.lastSyncResourceVersionMutex.Lock()
+	defer r.lastSyncResourceVersionMutex.Unlock()
+	r.isLastSyncResourceVersionUnavailable = isUnavailable
+}
+
+func isExpiredError(err error) bool {
+	// In Kubernetes 1.17 and earlier, the api server returns both apierrors.StatusReasonExpired and
+	// apierrors.StatusReasonGone for HTTP 410 (Gone) status code responses. In 1.18 the kube server is more consistent
+	// and always returns apierrors.StatusReasonExpired. For backward compatibility we can only remove the apierrors.IsGone
+	// check when we fully drop support for Kubernetes 1.17 servers from reflectors.
+	return apierrors.IsResourceExpired(err) || apierrors.IsGone(err)
+}
+
+func isTooLargeResourceVersionError(err error) bool {
+	if apierrors.HasStatusCause(err, metav1.CauseTypeResourceVersionTooLarge) {
+		return true
+	}
+	// In Kubernetes 1.17.0-1.18.5, the api server doesn't set the error status cause to
+	// metav1.CauseTypeResourceVersionTooLarge to indicate that the requested minimum resource
+	// version is larger than the largest currently available resource version. To ensure backward
+	// compatibility with these server versions we also need to detect the error based on the content
+	// of the error message field.
+	if !apierrors.IsTimeout(err) {
+		return false
+	}
+	apierr, ok := err.(apierrors.APIStatus)
+	if !ok || apierr == nil || apierr.Status().Details == nil {
+		return false
+	}
+	for _, cause := range apierr.Status().Details.Causes {
+		// Matches the message returned by api server 1.17.0-1.18.5 for this error condition
+		if cause.Message == "Too large resource version" {
+			return true
+		}
+	}
+	return false
+}

vendor/k8s.io/client-go/tools/cache/reflector_metrics.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2016 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.
+*/
+
+// This file provides abstractions for setting the provider (e.g., prometheus)
+// of metrics.
+
+package cache
+
+import (
+	"sync"
+)
+
+// GaugeMetric represents a single numerical value that can arbitrarily go up
+// and down.
+type GaugeMetric interface {
+	Set(float64)
+}
+
+// CounterMetric represents a single numerical value that only ever
+// goes up.
+type CounterMetric interface {
+	Inc()
+}
+
+// SummaryMetric captures individual observations.
+type SummaryMetric interface {
+	Observe(float64)
+}
+
+type noopMetric struct{}
+
+func (noopMetric) Inc()            {}
+func (noopMetric) Dec()            {}
+func (noopMetric) Observe(float64) {}
+func (noopMetric) Set(float64)     {}
+
+// MetricsProvider generates various metrics used by the reflector.
+type MetricsProvider interface {
+	NewListsMetric(name string) CounterMetric
+	NewListDurationMetric(name string) SummaryMetric
+	NewItemsInListMetric(name string) SummaryMetric
+
+	NewWatchesMetric(name string) CounterMetric
+	NewShortWatchesMetric(name string) CounterMetric
+	NewWatchDurationMetric(name string) SummaryMetric
+	NewItemsInWatchMetric(name string) SummaryMetric
+
+	NewLastResourceVersionMetric(name string) GaugeMetric
+}
+
+type noopMetricsProvider struct{}
+
+func (noopMetricsProvider) NewListsMetric(name string) CounterMetric         { return noopMetric{} }
+func (noopMetricsProvider) NewListDurationMetric(name string) SummaryMetric  { return noopMetric{} }
+func (noopMetricsProvider) NewItemsInListMetric(name string) SummaryMetric   { return noopMetric{} }
+func (noopMetricsProvider) NewWatchesMetric(name string) CounterMetric       { return noopMetric{} }
+func (noopMetricsProvider) NewShortWatchesMetric(name string) CounterMetric  { return noopMetric{} }
+func (noopMetricsProvider) NewWatchDurationMetric(name string) SummaryMetric { return noopMetric{} }
+func (noopMetricsProvider) NewItemsInWatchMetric(name string) SummaryMetric  { return noopMetric{} }
+func (noopMetricsProvider) NewLastResourceVersionMetric(name string) GaugeMetric {
+	return noopMetric{}
+}
+
+var metricsFactory = struct {
+	metricsProvider MetricsProvider
+	setProviders    sync.Once
+}{
+	metricsProvider: noopMetricsProvider{},
+}
+
+// SetReflectorMetricsProvider sets the metrics provider
+func SetReflectorMetricsProvider(metricsProvider MetricsProvider) {
+	metricsFactory.setProviders.Do(func() {
+		metricsFactory.metricsProvider = metricsProvider
+	})
+}

vendor/k8s.io/client-go/tools/cache/shared_informer.go

@@ -0,0 +1,855 @@
+/*
+Copyright 2015 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 cache
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/utils/buffer"
+	"k8s.io/utils/clock"
+
+	"k8s.io/klog/v2"
+)
+
+// SharedInformer provides eventually consistent linkage of its
+// clients to the authoritative state of a given collection of
+// objects.  An object is identified by its API group, kind/resource,
+// namespace (if any), and name; the `ObjectMeta.UID` is not part of
+// an object's ID as far as this contract is concerned.  One
+// SharedInformer provides linkage to objects of a particular API
+// group and kind/resource.  The linked object collection of a
+// SharedInformer may be further restricted to one namespace (if
+// applicable) and/or by label selector and/or field selector.
+//
+// The authoritative state of an object is what apiservers provide
+// access to, and an object goes through a strict sequence of states.
+// An object state is either (1) present with a ResourceVersion and
+// other appropriate content or (2) "absent".
+//
+// A SharedInformer maintains a local cache --- exposed by GetStore(),
+// by GetIndexer() in the case of an indexed informer, and possibly by
+// machinery involved in creating and/or accessing the informer --- of
+// the state of each relevant object.  This cache is eventually
+// consistent with the authoritative state.  This means that, unless
+// prevented by persistent communication problems, if ever a
+// particular object ID X is authoritatively associated with a state S
+// then for every SharedInformer I whose collection includes (X, S)
+// eventually either (1) I's cache associates X with S or a later
+// state of X, (2) I is stopped, or (3) the authoritative state
+// service for X terminates.  To be formally complete, we say that the
+// absent state meets any restriction by label selector or field
+// selector.
+//
+// For a given informer and relevant object ID X, the sequence of
+// states that appears in the informer's cache is a subsequence of the
+// states authoritatively associated with X.  That is, some states
+// might never appear in the cache but ordering among the appearing
+// states is correct.  Note, however, that there is no promise about
+// ordering between states seen for different objects.
+//
+// The local cache starts out empty, and gets populated and updated
+// during `Run()`.
+//
+// As a simple example, if a collection of objects is henceforth
+// unchanging, a SharedInformer is created that links to that
+// collection, and that SharedInformer is `Run()` then that
+// SharedInformer's cache eventually holds an exact copy of that
+// collection (unless it is stopped too soon, the authoritative state
+// service ends, or communication problems between the two
+// persistently thwart achievement).
+//
+// As another simple example, if the local cache ever holds a
+// non-absent state for some object ID and the object is eventually
+// removed from the authoritative state then eventually the object is
+// removed from the local cache (unless the SharedInformer is stopped
+// too soon, the authoritative state service ends, or communication
+// problems persistently thwart the desired result).
+//
+// The keys in the Store are of the form namespace/name for namespaced
+// objects, and are simply the name for non-namespaced objects.
+// Clients can use `MetaNamespaceKeyFunc(obj)` to extract the key for
+// a given object, and `SplitMetaNamespaceKey(key)` to split a key
+// into its constituent parts.
+//
+// Every query against the local cache is answered entirely from one
+// snapshot of the cache's state.  Thus, the result of a `List` call
+// will not contain two entries with the same namespace and name.
+//
+// A client is identified here by a ResourceEventHandler.  For every
+// update to the SharedInformer's local cache and for every client
+// added before `Run()`, eventually either the SharedInformer is
+// stopped or the client is notified of the update.  A client added
+// after `Run()` starts gets a startup batch of notifications of
+// additions of the objects existing in the cache at the time that
+// client was added; also, for every update to the SharedInformer's
+// local cache after that client was added, eventually either the
+// SharedInformer is stopped or that client is notified of that
+// update.  Client notifications happen after the corresponding cache
+// update and, in the case of a SharedIndexInformer, after the
+// corresponding index updates.  It is possible that additional cache
+// and index updates happen before such a prescribed notification.
+// For a given SharedInformer and client, the notifications are
+// delivered sequentially.  For a given SharedInformer, client, and
+// object ID, the notifications are delivered in order.  Because
+// `ObjectMeta.UID` has no role in identifying objects, it is possible
+// that when (1) object O1 with ID (e.g. namespace and name) X and
+// `ObjectMeta.UID` U1 in the SharedInformer's local cache is deleted
+// and later (2) another object O2 with ID X and ObjectMeta.UID U2 is
+// created the informer's clients are not notified of (1) and (2) but
+// rather are notified only of an update from O1 to O2. Clients that
+// need to detect such cases might do so by comparing the `ObjectMeta.UID`
+// field of the old and the new object in the code that handles update
+// notifications (i.e. `OnUpdate` method of ResourceEventHandler).
+//
+// A client must process each notification promptly; a SharedInformer
+// is not engineered to deal well with a large backlog of
+// notifications to deliver.  Lengthy processing should be passed off
+// to something else, for example through a
+// `client-go/util/workqueue`.
+//
+// A delete notification exposes the last locally known non-absent
+// state, except that its ResourceVersion is replaced with a
+// ResourceVersion in which the object is actually absent.
+type SharedInformer interface {
+	// AddEventHandler adds an event handler to the shared informer using the shared informer's resync
+	// period.  Events to a single handler are delivered sequentially, but there is no coordination
+	// between different handlers.
+	AddEventHandler(handler ResourceEventHandler)
+	// AddEventHandlerWithResyncPeriod adds an event handler to the
+	// shared informer with the requested resync period; zero means
+	// this handler does not care about resyncs.  The resync operation
+	// consists of delivering to the handler an update notification
+	// for every object in the informer's local cache; it does not add
+	// any interactions with the authoritative storage.  Some
+	// informers do no resyncs at all, not even for handlers added
+	// with a non-zero resyncPeriod.  For an informer that does
+	// resyncs, and for each handler that requests resyncs, that
+	// informer develops a nominal resync period that is no shorter
+	// than the requested period but may be longer.  The actual time
+	// between any two resyncs may be longer than the nominal period
+	// because the implementation takes time to do work and there may
+	// be competing load and scheduling noise.
+	AddEventHandlerWithResyncPeriod(handler ResourceEventHandler, resyncPeriod time.Duration)
+	// GetStore returns the informer's local cache as a Store.
+	GetStore() Store
+	// GetController is deprecated, it does nothing useful
+	GetController() Controller
+	// Run starts and runs the shared informer, returning after it stops.
+	// The informer will be stopped when stopCh is closed.
+	Run(stopCh <-chan struct{})
+	// HasSynced returns true if the shared informer's store has been
+	// informed by at least one full LIST of the authoritative state
+	// of the informer's object collection.  This is unrelated to "resync".
+	HasSynced() bool
+	// LastSyncResourceVersion is the resource version observed when last synced with the underlying
+	// store. The value returned is not synchronized with access to the underlying store and is not
+	// thread-safe.
+	LastSyncResourceVersion() string
+
+	// The WatchErrorHandler is called whenever ListAndWatch drops the
+	// connection with an error. After calling this handler, the informer
+	// will backoff and retry.
+	//
+	// The default implementation looks at the error type and tries to log
+	// the error message at an appropriate level.
+	//
+	// There's only one handler, so if you call this multiple times, last one
+	// wins; calling after the informer has been started returns an error.
+	//
+	// The handler is intended for visibility, not to e.g. pause the consumers.
+	// The handler should return quickly - any expensive processing should be
+	// offloaded.
+	SetWatchErrorHandler(handler WatchErrorHandler) error
+
+	// The TransformFunc is called for each object which is about to be stored.
+	//
+	// This function is intended for you to take the opportunity to
+	// remove, transform, or normalize fields. One use case is to strip unused
+	// metadata fields out of objects to save on RAM cost.
+	//
+	// Must be set before starting the informer.
+	//
+	// Note: Since the object given to the handler may be already shared with
+	//	other goroutines, it is advisable to copy the object being
+	//  transform before mutating it at all and returning the copy to prevent
+	//	data races.
+	SetTransform(handler TransformFunc) error
+}
+
+// SharedIndexInformer provides add and get Indexers ability based on SharedInformer.
+type SharedIndexInformer interface {
+	SharedInformer
+	// AddIndexers add indexers to the informer before it starts.
+	AddIndexers(indexers Indexers) error
+	GetIndexer() Indexer
+}
+
+// NewSharedInformer creates a new instance for the listwatcher.
+func NewSharedInformer(lw ListerWatcher, exampleObject runtime.Object, defaultEventHandlerResyncPeriod time.Duration) SharedInformer {
+	return NewSharedIndexInformer(lw, exampleObject, defaultEventHandlerResyncPeriod, Indexers{})
+}
+
+// NewSharedIndexInformer creates a new instance for the listwatcher.
+// The created informer will not do resyncs if the given
+// defaultEventHandlerResyncPeriod is zero.  Otherwise: for each
+// handler that with a non-zero requested resync period, whether added
+// before or after the informer starts, the nominal resync period is
+// the requested resync period rounded up to a multiple of the
+// informer's resync checking period.  Such an informer's resync
+// checking period is established when the informer starts running,
+// and is the maximum of (a) the minimum of the resync periods
+// requested before the informer starts and the
+// defaultEventHandlerResyncPeriod given here and (b) the constant
+// `minimumResyncPeriod` defined in this file.
+func NewSharedIndexInformer(lw ListerWatcher, exampleObject runtime.Object, defaultEventHandlerResyncPeriod time.Duration, indexers Indexers) SharedIndexInformer {
+	realClock := &clock.RealClock{}
+	sharedIndexInformer := &sharedIndexInformer{
+		processor:                       &sharedProcessor{clock: realClock},
+		indexer:                         NewIndexer(DeletionHandlingMetaNamespaceKeyFunc, indexers),
+		listerWatcher:                   lw,
+		objectType:                      exampleObject,
+		resyncCheckPeriod:               defaultEventHandlerResyncPeriod,
+		defaultEventHandlerResyncPeriod: defaultEventHandlerResyncPeriod,
+		cacheMutationDetector:           NewCacheMutationDetector(fmt.Sprintf("%T", exampleObject)),
+		clock:                           realClock,
+	}
+	return sharedIndexInformer
+}
+
+// InformerSynced is a function that can be used to determine if an informer has synced.  This is useful for determining if caches have synced.
+type InformerSynced func() bool
+
+const (
+	// syncedPollPeriod controls how often you look at the status of your sync funcs
+	syncedPollPeriod = 100 * time.Millisecond
+
+	// initialBufferSize is the initial number of event notifications that can be buffered.
+	initialBufferSize = 1024
+)
+
+// WaitForNamedCacheSync is a wrapper around WaitForCacheSync that generates log messages
+// indicating that the caller identified by name is waiting for syncs, followed by
+// either a successful or failed sync.
+func WaitForNamedCacheSync(controllerName string, stopCh <-chan struct{}, cacheSyncs ...InformerSynced) bool {
+	klog.Infof("Waiting for caches to sync for %s", controllerName)
+
+	if !WaitForCacheSync(stopCh, cacheSyncs...) {
+		utilruntime.HandleError(fmt.Errorf("unable to sync caches for %s", controllerName))
+		return false
+	}
+
+	klog.Infof("Caches are synced for %s", controllerName)
+	return true
+}
+
+// WaitForCacheSync waits for caches to populate.  It returns true if it was successful, false
+// if the controller should shutdown
+// callers should prefer WaitForNamedCacheSync()
+func WaitForCacheSync(stopCh <-chan struct{}, cacheSyncs ...InformerSynced) bool {
+	err := wait.PollImmediateUntil(syncedPollPeriod,
+		func() (bool, error) {
+			for _, syncFunc := range cacheSyncs {
+				if !syncFunc() {
+					return false, nil
+				}
+			}
+			return true, nil
+		},
+		stopCh)
+	if err != nil {
+		klog.V(2).Infof("stop requested")
+		return false
+	}
+
+	klog.V(4).Infof("caches populated")
+	return true
+}
+
+// `*sharedIndexInformer` implements SharedIndexInformer and has three
+// main components.  One is an indexed local cache, `indexer Indexer`.
+// The second main component is a Controller that pulls
+// objects/notifications using the ListerWatcher and pushes them into
+// a DeltaFIFO --- whose knownObjects is the informer's local cache
+// --- while concurrently Popping Deltas values from that fifo and
+// processing them with `sharedIndexInformer::HandleDeltas`.  Each
+// invocation of HandleDeltas, which is done with the fifo's lock
+// held, processes each Delta in turn.  For each Delta this both
+// updates the local cache and stuffs the relevant notification into
+// the sharedProcessor.  The third main component is that
+// sharedProcessor, which is responsible for relaying those
+// notifications to each of the informer's clients.
+type sharedIndexInformer struct {
+	indexer    Indexer
+	controller Controller
+
+	processor             *sharedProcessor
+	cacheMutationDetector MutationDetector
+
+	listerWatcher ListerWatcher
+
+	// objectType is an example object of the type this informer is
+	// expected to handle.  Only the type needs to be right, except
+	// that when that is `unstructured.Unstructured` the object's
+	// `"apiVersion"` and `"kind"` must also be right.
+	objectType runtime.Object
+
+	// resyncCheckPeriod is how often we want the reflector's resync timer to fire so it can call
+	// shouldResync to check if any of our listeners need a resync.
+	resyncCheckPeriod time.Duration
+	// defaultEventHandlerResyncPeriod is the default resync period for any handlers added via
+	// AddEventHandler (i.e. they don't specify one and just want to use the shared informer's default
+	// value).
+	defaultEventHandlerResyncPeriod time.Duration
+	// clock allows for testability
+	clock clock.Clock
+
+	started, stopped bool
+	startedLock      sync.Mutex
+
+	// blockDeltas gives a way to stop all event distribution so that a late event handler
+	// can safely join the shared informer.
+	blockDeltas sync.Mutex
+
+	// Called whenever the ListAndWatch drops the connection with an error.
+	watchErrorHandler WatchErrorHandler
+
+	transform TransformFunc
+}
+
+// dummyController hides the fact that a SharedInformer is different from a dedicated one
+// where a caller can `Run`.  The run method is disconnected in this case, because higher
+// level logic will decide when to start the SharedInformer and related controller.
+// Because returning information back is always asynchronous, the legacy callers shouldn't
+// notice any change in behavior.
+type dummyController struct {
+	informer *sharedIndexInformer
+}
+
+func (v *dummyController) Run(stopCh <-chan struct{}) {
+}
+
+func (v *dummyController) HasSynced() bool {
+	return v.informer.HasSynced()
+}
+
+func (v *dummyController) LastSyncResourceVersion() string {
+	return ""
+}
+
+type updateNotification struct {
+	oldObj interface{}
+	newObj interface{}
+}
+
+type addNotification struct {
+	newObj interface{}
+}
+
+type deleteNotification struct {
+	oldObj interface{}
+}
+
+func (s *sharedIndexInformer) SetWatchErrorHandler(handler WatchErrorHandler) error {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.started {
+		return fmt.Errorf("informer has already started")
+	}
+
+	s.watchErrorHandler = handler
+	return nil
+}
+
+func (s *sharedIndexInformer) SetTransform(handler TransformFunc) error {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.started {
+		return fmt.Errorf("informer has already started")
+	}
+
+	s.transform = handler
+	return nil
+}
+
+func (s *sharedIndexInformer) Run(stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+
+	if s.HasStarted() {
+		klog.Warningf("The sharedIndexInformer has started, run more than once is not allowed")
+		return
+	}
+	fifo := NewDeltaFIFOWithOptions(DeltaFIFOOptions{
+		KnownObjects:          s.indexer,
+		EmitDeltaTypeReplaced: true,
+	})
+
+	cfg := &Config{
+		Queue:            fifo,
+		ListerWatcher:    s.listerWatcher,
+		ObjectType:       s.objectType,
+		FullResyncPeriod: s.resyncCheckPeriod,
+		RetryOnError:     false,
+		ShouldResync:     s.processor.shouldResync,
+
+		Process:           s.HandleDeltas,
+		WatchErrorHandler: s.watchErrorHandler,
+	}
+
+	func() {
+		s.startedLock.Lock()
+		defer s.startedLock.Unlock()
+
+		s.controller = New(cfg)
+		s.controller.(*controller).clock = s.clock
+		s.started = true
+	}()
+
+	// Separate stop channel because Processor should be stopped strictly after controller
+	processorStopCh := make(chan struct{})
+	var wg wait.Group
+	defer wg.Wait()              // Wait for Processor to stop
+	defer close(processorStopCh) // Tell Processor to stop
+	wg.StartWithChannel(processorStopCh, s.cacheMutationDetector.Run)
+	wg.StartWithChannel(processorStopCh, s.processor.run)
+
+	defer func() {
+		s.startedLock.Lock()
+		defer s.startedLock.Unlock()
+		s.stopped = true // Don't want any new listeners
+	}()
+	s.controller.Run(stopCh)
+}
+
+func (s *sharedIndexInformer) HasStarted() bool {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+	return s.started
+}
+
+func (s *sharedIndexInformer) HasSynced() bool {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.controller == nil {
+		return false
+	}
+	return s.controller.HasSynced()
+}
+
+func (s *sharedIndexInformer) LastSyncResourceVersion() string {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.controller == nil {
+		return ""
+	}
+	return s.controller.LastSyncResourceVersion()
+}
+
+func (s *sharedIndexInformer) GetStore() Store {
+	return s.indexer
+}
+
+func (s *sharedIndexInformer) GetIndexer() Indexer {
+	return s.indexer
+}
+
+func (s *sharedIndexInformer) AddIndexers(indexers Indexers) error {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.started {
+		return fmt.Errorf("informer has already started")
+	}
+
+	return s.indexer.AddIndexers(indexers)
+}
+
+func (s *sharedIndexInformer) GetController() Controller {
+	return &dummyController{informer: s}
+}
+
+func (s *sharedIndexInformer) AddEventHandler(handler ResourceEventHandler) {
+	s.AddEventHandlerWithResyncPeriod(handler, s.defaultEventHandlerResyncPeriod)
+}
+
+func determineResyncPeriod(desired, check time.Duration) time.Duration {
+	if desired == 0 {
+		return desired
+	}
+	if check == 0 {
+		klog.Warningf("The specified resyncPeriod %v is invalid because this shared informer doesn't support resyncing", desired)
+		return 0
+	}
+	if desired < check {
+		klog.Warningf("The specified resyncPeriod %v is being increased to the minimum resyncCheckPeriod %v", desired, check)
+		return check
+	}
+	return desired
+}
+
+const minimumResyncPeriod = 1 * time.Second
+
+func (s *sharedIndexInformer) AddEventHandlerWithResyncPeriod(handler ResourceEventHandler, resyncPeriod time.Duration) {
+	s.startedLock.Lock()
+	defer s.startedLock.Unlock()
+
+	if s.stopped {
+		klog.V(2).Infof("Handler %v was not added to shared informer because it has stopped already", handler)
+		return
+	}
+
+	if resyncPeriod > 0 {
+		if resyncPeriod < minimumResyncPeriod {
+			klog.Warningf("resyncPeriod %v is too small. Changing it to the minimum allowed value of %v", resyncPeriod, minimumResyncPeriod)
+			resyncPeriod = minimumResyncPeriod
+		}
+
+		if resyncPeriod < s.resyncCheckPeriod {
+			if s.started {
+				klog.Warningf("resyncPeriod %v is smaller than resyncCheckPeriod %v and the informer has already started. Changing it to %v", resyncPeriod, s.resyncCheckPeriod, s.resyncCheckPeriod)
+				resyncPeriod = s.resyncCheckPeriod
+			} else {
+				// if the event handler's resyncPeriod is smaller than the current resyncCheckPeriod, update
+				// resyncCheckPeriod to match resyncPeriod and adjust the resync periods of all the listeners
+				// accordingly
+				s.resyncCheckPeriod = resyncPeriod
+				s.processor.resyncCheckPeriodChanged(resyncPeriod)
+			}
+		}
+	}
+
+	listener := newProcessListener(handler, resyncPeriod, determineResyncPeriod(resyncPeriod, s.resyncCheckPeriod), s.clock.Now(), initialBufferSize)
+
+	if !s.started {
+		s.processor.addListener(listener)
+		return
+	}
+
+	// in order to safely join, we have to
+	// 1. stop sending add/update/delete notifications
+	// 2. do a list against the store
+	// 3. send synthetic "Add" events to the new handler
+	// 4. unblock
+	s.blockDeltas.Lock()
+	defer s.blockDeltas.Unlock()
+
+	s.processor.addListener(listener)
+	for _, item := range s.indexer.List() {
+		listener.add(addNotification{newObj: item})
+	}
+}
+
+func (s *sharedIndexInformer) HandleDeltas(obj interface{}) error {
+	s.blockDeltas.Lock()
+	defer s.blockDeltas.Unlock()
+
+	if deltas, ok := obj.(Deltas); ok {
+		return processDeltas(s, s.indexer, s.transform, deltas)
+	}
+	return errors.New("object given as Process argument is not Deltas")
+}
+
+// Conforms to ResourceEventHandler
+func (s *sharedIndexInformer) OnAdd(obj interface{}) {
+	// Invocation of this function is locked under s.blockDeltas, so it is
+	// save to distribute the notification
+	s.cacheMutationDetector.AddObject(obj)
+	s.processor.distribute(addNotification{newObj: obj}, false)
+}
+
+// Conforms to ResourceEventHandler
+func (s *sharedIndexInformer) OnUpdate(old, new interface{}) {
+	isSync := false
+
+	// If is a Sync event, isSync should be true
+	// If is a Replaced event, isSync is true if resource version is unchanged.
+	// If RV is unchanged: this is a Sync/Replaced event, so isSync is true
+
+	if accessor, err := meta.Accessor(new); err == nil {
+		if oldAccessor, err := meta.Accessor(old); err == nil {
+			// Events that didn't change resourceVersion are treated as resync events
+			// and only propagated to listeners that requested resync
+			isSync = accessor.GetResourceVersion() == oldAccessor.GetResourceVersion()
+		}
+	}
+
+	// Invocation of this function is locked under s.blockDeltas, so it is
+	// save to distribute the notification
+	s.cacheMutationDetector.AddObject(new)
+	s.processor.distribute(updateNotification{oldObj: old, newObj: new}, isSync)
+}
+
+// Conforms to ResourceEventHandler
+func (s *sharedIndexInformer) OnDelete(old interface{}) {
+	// Invocation of this function is locked under s.blockDeltas, so it is
+	// save to distribute the notification
+	s.processor.distribute(deleteNotification{oldObj: old}, false)
+}
+
+// sharedProcessor has a collection of processorListener and can
+// distribute a notification object to its listeners.  There are two
+// kinds of distribute operations.  The sync distributions go to a
+// subset of the listeners that (a) is recomputed in the occasional
+// calls to shouldResync and (b) every listener is initially put in.
+// The non-sync distributions go to every listener.
+type sharedProcessor struct {
+	listenersStarted bool
+	listenersLock    sync.RWMutex
+	listeners        []*processorListener
+	syncingListeners []*processorListener
+	clock            clock.Clock
+	wg               wait.Group
+}
+
+func (p *sharedProcessor) addListener(listener *processorListener) {
+	p.listenersLock.Lock()
+	defer p.listenersLock.Unlock()
+
+	p.addListenerLocked(listener)
+	if p.listenersStarted {
+		p.wg.Start(listener.run)
+		p.wg.Start(listener.pop)
+	}
+}
+
+func (p *sharedProcessor) addListenerLocked(listener *processorListener) {
+	p.listeners = append(p.listeners, listener)
+	p.syncingListeners = append(p.syncingListeners, listener)
+}
+
+func (p *sharedProcessor) distribute(obj interface{}, sync bool) {
+	p.listenersLock.RLock()
+	defer p.listenersLock.RUnlock()
+
+	if sync {
+		for _, listener := range p.syncingListeners {
+			listener.add(obj)
+		}
+	} else {
+		for _, listener := range p.listeners {
+			listener.add(obj)
+		}
+	}
+}
+
+func (p *sharedProcessor) run(stopCh <-chan struct{}) {
+	func() {
+		p.listenersLock.RLock()
+		defer p.listenersLock.RUnlock()
+		for _, listener := range p.listeners {
+			p.wg.Start(listener.run)
+			p.wg.Start(listener.pop)
+		}
+		p.listenersStarted = true
+	}()
+	<-stopCh
+	p.listenersLock.RLock()
+	defer p.listenersLock.RUnlock()
+	for _, listener := range p.listeners {
+		close(listener.addCh) // Tell .pop() to stop. .pop() will tell .run() to stop
+	}
+	p.wg.Wait() // Wait for all .pop() and .run() to stop
+}
+
+// shouldResync queries every listener to determine if any of them need a resync, based on each
+// listener's resyncPeriod.
+func (p *sharedProcessor) shouldResync() bool {
+	p.listenersLock.Lock()
+	defer p.listenersLock.Unlock()
+
+	p.syncingListeners = []*processorListener{}
+
+	resyncNeeded := false
+	now := p.clock.Now()
+	for _, listener := range p.listeners {
+		// need to loop through all the listeners to see if they need to resync so we can prepare any
+		// listeners that are going to be resyncing.
+		if listener.shouldResync(now) {
+			resyncNeeded = true
+			p.syncingListeners = append(p.syncingListeners, listener)
+			listener.determineNextResync(now)
+		}
+	}
+	return resyncNeeded
+}
+
+func (p *sharedProcessor) resyncCheckPeriodChanged(resyncCheckPeriod time.Duration) {
+	p.listenersLock.RLock()
+	defer p.listenersLock.RUnlock()
+
+	for _, listener := range p.listeners {
+		resyncPeriod := determineResyncPeriod(listener.requestedResyncPeriod, resyncCheckPeriod)
+		listener.setResyncPeriod(resyncPeriod)
+	}
+}
+
+// processorListener relays notifications from a sharedProcessor to
+// one ResourceEventHandler --- using two goroutines, two unbuffered
+// channels, and an unbounded ring buffer.  The `add(notification)`
+// function sends the given notification to `addCh`.  One goroutine
+// runs `pop()`, which pumps notifications from `addCh` to `nextCh`
+// using storage in the ring buffer while `nextCh` is not keeping up.
+// Another goroutine runs `run()`, which receives notifications from
+// `nextCh` and synchronously invokes the appropriate handler method.
+//
+// processorListener also keeps track of the adjusted requested resync
+// period of the listener.
+type processorListener struct {
+	nextCh chan interface{}
+	addCh  chan interface{}
+
+	handler ResourceEventHandler
+
+	// pendingNotifications is an unbounded ring buffer that holds all notifications not yet distributed.
+	// There is one per listener, but a failing/stalled listener will have infinite pendingNotifications
+	// added until we OOM.
+	// TODO: This is no worse than before, since reflectors were backed by unbounded DeltaFIFOs, but
+	// we should try to do something better.
+	pendingNotifications buffer.RingGrowing
+
+	// requestedResyncPeriod is how frequently the listener wants a
+	// full resync from the shared informer, but modified by two
+	// adjustments.  One is imposing a lower bound,
+	// `minimumResyncPeriod`.  The other is another lower bound, the
+	// sharedIndexInformer's `resyncCheckPeriod`, that is imposed (a) only
+	// in AddEventHandlerWithResyncPeriod invocations made after the
+	// sharedIndexInformer starts and (b) only if the informer does
+	// resyncs at all.
+	requestedResyncPeriod time.Duration
+	// resyncPeriod is the threshold that will be used in the logic
+	// for this listener.  This value differs from
+	// requestedResyncPeriod only when the sharedIndexInformer does
+	// not do resyncs, in which case the value here is zero.  The
+	// actual time between resyncs depends on when the
+	// sharedProcessor's `shouldResync` function is invoked and when
+	// the sharedIndexInformer processes `Sync` type Delta objects.
+	resyncPeriod time.Duration
+	// nextResync is the earliest time the listener should get a full resync
+	nextResync time.Time
+	// resyncLock guards access to resyncPeriod and nextResync
+	resyncLock sync.Mutex
+}
+
+func newProcessListener(handler ResourceEventHandler, requestedResyncPeriod, resyncPeriod time.Duration, now time.Time, bufferSize int) *processorListener {
+	ret := &processorListener{
+		nextCh:                make(chan interface{}),
+		addCh:                 make(chan interface{}),
+		handler:               handler,
+		pendingNotifications:  *buffer.NewRingGrowing(bufferSize),
+		requestedResyncPeriod: requestedResyncPeriod,
+		resyncPeriod:          resyncPeriod,
+	}
+
+	ret.determineNextResync(now)
+
+	return ret
+}
+
+func (p *processorListener) add(notification interface{}) {
+	p.addCh <- notification
+}
+
+func (p *processorListener) pop() {
+	defer utilruntime.HandleCrash()
+	defer close(p.nextCh) // Tell .run() to stop
+
+	var nextCh chan<- interface{}
+	var notification interface{}
+	for {
+		select {
+		case nextCh <- notification:
+			// Notification dispatched
+			var ok bool
+			notification, ok = p.pendingNotifications.ReadOne()
+			if !ok { // Nothing to pop
+				nextCh = nil // Disable this select case
+			}
+		case notificationToAdd, ok := <-p.addCh:
+			if !ok {
+				return
+			}
+			if notification == nil { // No notification to pop (and pendingNotifications is empty)
+				// Optimize the case - skip adding to pendingNotifications
+				notification = notificationToAdd
+				nextCh = p.nextCh
+			} else { // There is already a notification waiting to be dispatched
+				p.pendingNotifications.WriteOne(notificationToAdd)
+			}
+		}
+	}
+}
+
+func (p *processorListener) run() {
+	// this call blocks until the channel is closed.  When a panic happens during the notification
+	// we will catch it, **the offending item will be skipped!**, and after a short delay (one second)
+	// the next notification will be attempted.  This is usually better than the alternative of never
+	// delivering again.
+	stopCh := make(chan struct{})
+	wait.Until(func() {
+		for next := range p.nextCh {
+			switch notification := next.(type) {
+			case updateNotification:
+				p.handler.OnUpdate(notification.oldObj, notification.newObj)
+			case addNotification:
+				p.handler.OnAdd(notification.newObj)
+			case deleteNotification:
+				p.handler.OnDelete(notification.oldObj)
+			default:
+				utilruntime.HandleError(fmt.Errorf("unrecognized notification: %T", next))
+			}
+		}
+		// the only way to get here is if the p.nextCh is empty and closed
+		close(stopCh)
+	}, 1*time.Second, stopCh)
+}
+
+// shouldResync deterimines if the listener needs a resync. If the listener's resyncPeriod is 0,
+// this always returns false.
+func (p *processorListener) shouldResync(now time.Time) bool {
+	p.resyncLock.Lock()
+	defer p.resyncLock.Unlock()
+
+	if p.resyncPeriod == 0 {
+		return false
+	}
+
+	return now.After(p.nextResync) || now.Equal(p.nextResync)
+}
+
+func (p *processorListener) determineNextResync(now time.Time) {
+	p.resyncLock.Lock()
+	defer p.resyncLock.Unlock()
+
+	p.nextResync = now.Add(p.resyncPeriod)
+}
+
+func (p *processorListener) setResyncPeriod(resyncPeriod time.Duration) {
+	p.resyncLock.Lock()
+	defer p.resyncLock.Unlock()
+
+	p.resyncPeriod = resyncPeriod
+}

vendor/k8s.io/client-go/tools/cache/store.go

@@ -0,0 +1,271 @@
+/*
+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 cache
+
+import (
+	"fmt"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+)
+
+// Store is a generic object storage and processing interface.  A
+// Store holds a map from string keys to accumulators, and has
+// operations to add, update, and delete a given object to/from the
+// accumulator currently associated with a given key.  A Store also
+// knows how to extract the key from a given object, so many operations
+// are given only the object.
+//
+// In the simplest Store implementations each accumulator is simply
+// the last given object, or empty after Delete, and thus the Store's
+// behavior is simple storage.
+//
+// Reflector knows how to watch a server and update a Store.  This
+// package provides a variety of implementations of Store.
+type Store interface {
+
+	// Add adds the given object to the accumulator associated with the given object's key
+	Add(obj interface{}) error
+
+	// Update updates the given object in the accumulator associated with the given object's key
+	Update(obj interface{}) error
+
+	// Delete deletes the given object from the accumulator associated with the given object's key
+	Delete(obj interface{}) error
+
+	// List returns a list of all the currently non-empty accumulators
+	List() []interface{}
+
+	// ListKeys returns a list of all the keys currently associated with non-empty accumulators
+	ListKeys() []string
+
+	// Get returns the accumulator associated with the given object's key
+	Get(obj interface{}) (item interface{}, exists bool, err error)
+
+	// GetByKey returns the accumulator associated with the given key
+	GetByKey(key string) (item interface{}, exists bool, err error)
+
+	// Replace will delete the contents of the store, using instead the
+	// given list. Store takes ownership of the list, you should not reference
+	// it after calling this function.
+	Replace([]interface{}, string) error
+
+	// Resync is meaningless in the terms appearing here but has
+	// meaning in some implementations that have non-trivial
+	// additional behavior (e.g., DeltaFIFO).
+	Resync() error
+}
+
+// KeyFunc knows how to make a key from an object. Implementations should be deterministic.
+type KeyFunc func(obj interface{}) (string, error)
+
+// KeyError will be returned any time a KeyFunc gives an error; it includes the object
+// at fault.
+type KeyError struct {
+	Obj interface{}
+	Err error
+}
+
+// Error gives a human-readable description of the error.
+func (k KeyError) Error() string {
+	return fmt.Sprintf("couldn't create key for object %+v: %v", k.Obj, k.Err)
+}
+
+// Unwrap implements errors.Unwrap
+func (k KeyError) Unwrap() error {
+	return k.Err
+}
+
+// ExplicitKey can be passed to MetaNamespaceKeyFunc if you have the key for
+// the object but not the object itself.
+type ExplicitKey string
+
+// MetaNamespaceKeyFunc is a convenient default KeyFunc which knows how to make
+// keys for API objects which implement meta.Interface.
+// The key uses the format <namespace>/<name> unless <namespace> is empty, then
+// it's just <name>.
+//
+// TODO: replace key-as-string with a key-as-struct so that this
+// packing/unpacking won't be necessary.
+func MetaNamespaceKeyFunc(obj interface{}) (string, error) {
+	if key, ok := obj.(ExplicitKey); ok {
+		return string(key), nil
+	}
+	meta, err := meta.Accessor(obj)
+	if err != nil {
+		return "", fmt.Errorf("object has no meta: %v", err)
+	}
+	if len(meta.GetNamespace()) > 0 {
+		return meta.GetNamespace() + "/" + meta.GetName(), nil
+	}
+	return meta.GetName(), nil
+}
+
+// SplitMetaNamespaceKey returns the namespace and name that
+// MetaNamespaceKeyFunc encoded into key.
+//
+// TODO: replace key-as-string with a key-as-struct so that this
+// packing/unpacking won't be necessary.
+func SplitMetaNamespaceKey(key string) (namespace, name string, err error) {
+	parts := strings.Split(key, "/")
+	switch len(parts) {
+	case 1:
+		// name only, no namespace
+		return "", parts[0], nil
+	case 2:
+		// namespace and name
+		return parts[0], parts[1], nil
+	}
+
+	return "", "", fmt.Errorf("unexpected key format: %q", key)
+}
+
+// `*cache` implements Indexer in terms of a ThreadSafeStore and an
+// associated KeyFunc.
+type cache struct {
+	// cacheStorage bears the burden of thread safety for the cache
+	cacheStorage ThreadSafeStore
+	// keyFunc is used to make the key for objects stored in and retrieved from items, and
+	// should be deterministic.
+	keyFunc KeyFunc
+}
+
+var _ Store = &cache{}
+
+// Add inserts an item into the cache.
+func (c *cache) Add(obj interface{}) error {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	c.cacheStorage.Add(key, obj)
+	return nil
+}
+
+// Update sets an item in the cache to its updated state.
+func (c *cache) Update(obj interface{}) error {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	c.cacheStorage.Update(key, obj)
+	return nil
+}
+
+// Delete removes an item from the cache.
+func (c *cache) Delete(obj interface{}) error {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return KeyError{obj, err}
+	}
+	c.cacheStorage.Delete(key)
+	return nil
+}
+
+// List returns a list of all the items.
+// List is completely threadsafe as long as you treat all items as immutable.
+func (c *cache) List() []interface{} {
+	return c.cacheStorage.List()
+}
+
+// ListKeys returns a list of all the keys of the objects currently
+// in the cache.
+func (c *cache) ListKeys() []string {
+	return c.cacheStorage.ListKeys()
+}
+
+// GetIndexers returns the indexers of cache
+func (c *cache) GetIndexers() Indexers {
+	return c.cacheStorage.GetIndexers()
+}
+
+// Index returns a list of items that match on the index function
+// Index is thread-safe so long as you treat all items as immutable
+func (c *cache) Index(indexName string, obj interface{}) ([]interface{}, error) {
+	return c.cacheStorage.Index(indexName, obj)
+}
+
+func (c *cache) IndexKeys(indexName, indexKey string) ([]string, error) {
+	return c.cacheStorage.IndexKeys(indexName, indexKey)
+}
+
+// ListIndexFuncValues returns the list of generated values of an Index func
+func (c *cache) ListIndexFuncValues(indexName string) []string {
+	return c.cacheStorage.ListIndexFuncValues(indexName)
+}
+
+func (c *cache) ByIndex(indexName, indexKey string) ([]interface{}, error) {
+	return c.cacheStorage.ByIndex(indexName, indexKey)
+}
+
+func (c *cache) AddIndexers(newIndexers Indexers) error {
+	return c.cacheStorage.AddIndexers(newIndexers)
+}
+
+// Get returns the requested item, or sets exists=false.
+// Get is completely threadsafe as long as you treat all items as immutable.
+func (c *cache) Get(obj interface{}) (item interface{}, exists bool, err error) {
+	key, err := c.keyFunc(obj)
+	if err != nil {
+		return nil, false, KeyError{obj, err}
+	}
+	return c.GetByKey(key)
+}
+
+// GetByKey returns the request item, or exists=false.
+// GetByKey is completely threadsafe as long as you treat all items as immutable.
+func (c *cache) GetByKey(key string) (item interface{}, exists bool, err error) {
+	item, exists = c.cacheStorage.Get(key)
+	return item, exists, nil
+}
+
+// Replace will delete the contents of 'c', using instead the given list.
+// 'c' takes ownership of the list, you should not reference the list again
+// after calling this function.
+func (c *cache) Replace(list []interface{}, resourceVersion string) error {
+	items := make(map[string]interface{}, len(list))
+	for _, item := range list {
+		key, err := c.keyFunc(item)
+		if err != nil {
+			return KeyError{item, err}
+		}
+		items[key] = item
+	}
+	c.cacheStorage.Replace(items, resourceVersion)
+	return nil
+}
+
+// Resync is meaningless for one of these
+func (c *cache) Resync() error {
+	return nil
+}
+
+// NewStore returns a Store implemented simply with a map and a lock.
+func NewStore(keyFunc KeyFunc) Store {
+	return &cache{
+		cacheStorage: NewThreadSafeStore(Indexers{}, Indices{}),
+		keyFunc:      keyFunc,
+	}
+}
+
+// NewIndexer returns an Indexer implemented simply with a map and a lock.
+func NewIndexer(keyFunc KeyFunc, indexers Indexers) Indexer {
+	return &cache{
+		cacheStorage: NewThreadSafeStore(indexers, Indices{}),
+		keyFunc:      keyFunc,
+	}
+}

vendor/k8s.io/client-go/tools/cache/thread_safe_store.go

@@ -0,0 +1,332 @@
+/*
+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 cache
+
+import (
+	"fmt"
+	"sync"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// ThreadSafeStore is an interface that allows concurrent indexed
+// access to a storage backend.  It is like Indexer but does not
+// (necessarily) know how to extract the Store key from a given
+// object.
+//
+// TL;DR caveats: you must not modify anything returned by Get or List as it will break
+// the indexing feature in addition to not being thread safe.
+//
+// The guarantees of thread safety provided by List/Get are only valid if the caller
+// treats returned items as read-only. For example, a pointer inserted in the store
+// through `Add` will be returned as is by `Get`. Multiple clients might invoke `Get`
+// on the same key and modify the pointer in a non-thread-safe way. Also note that
+// modifying objects stored by the indexers (if any) will *not* automatically lead
+// to a re-index. So it's not a good idea to directly modify the objects returned by
+// Get/List, in general.
+type ThreadSafeStore interface {
+	Add(key string, obj interface{})
+	Update(key string, obj interface{})
+	Delete(key string)
+	Get(key string) (item interface{}, exists bool)
+	List() []interface{}
+	ListKeys() []string
+	Replace(map[string]interface{}, string)
+	Index(indexName string, obj interface{}) ([]interface{}, error)
+	IndexKeys(indexName, indexKey string) ([]string, error)
+	ListIndexFuncValues(name string) []string
+	ByIndex(indexName, indexKey string) ([]interface{}, error)
+	GetIndexers() Indexers
+
+	// AddIndexers adds more indexers to this store.  If you call this after you already have data
+	// in the store, the results are undefined.
+	AddIndexers(newIndexers Indexers) error
+	// Resync is a no-op and is deprecated
+	Resync() error
+}
+
+// threadSafeMap implements ThreadSafeStore
+type threadSafeMap struct {
+	lock  sync.RWMutex
+	items map[string]interface{}
+
+	// indexers maps a name to an IndexFunc
+	indexers Indexers
+	// indices maps a name to an Index
+	indices Indices
+}
+
+func (c *threadSafeMap) Add(key string, obj interface{}) {
+	c.Update(key, obj)
+}
+
+func (c *threadSafeMap) Update(key string, obj interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	oldObject := c.items[key]
+	c.items[key] = obj
+	c.updateIndices(oldObject, obj, key)
+}
+
+func (c *threadSafeMap) Delete(key string) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if obj, exists := c.items[key]; exists {
+		c.updateIndices(obj, nil, key)
+		delete(c.items, key)
+	}
+}
+
+func (c *threadSafeMap) Get(key string) (item interface{}, exists bool) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	item, exists = c.items[key]
+	return item, exists
+}
+
+func (c *threadSafeMap) List() []interface{} {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	list := make([]interface{}, 0, len(c.items))
+	for _, item := range c.items {
+		list = append(list, item)
+	}
+	return list
+}
+
+// ListKeys returns a list of all the keys of the objects currently
+// in the threadSafeMap.
+func (c *threadSafeMap) ListKeys() []string {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	list := make([]string, 0, len(c.items))
+	for key := range c.items {
+		list = append(list, key)
+	}
+	return list
+}
+
+func (c *threadSafeMap) Replace(items map[string]interface{}, resourceVersion string) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.items = items
+
+	// rebuild any index
+	c.indices = Indices{}
+	for key, item := range c.items {
+		c.updateIndices(nil, item, key)
+	}
+}
+
+// Index returns a list of items that match the given object on the index function.
+// Index is thread-safe so long as you treat all items as immutable.
+func (c *threadSafeMap) Index(indexName string, obj interface{}) ([]interface{}, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	indexFunc := c.indexers[indexName]
+	if indexFunc == nil {
+		return nil, fmt.Errorf("Index with name %s does not exist", indexName)
+	}
+
+	indexedValues, err := indexFunc(obj)
+	if err != nil {
+		return nil, err
+	}
+	index := c.indices[indexName]
+
+	var storeKeySet sets.String
+	if len(indexedValues) == 1 {
+		// In majority of cases, there is exactly one value matching.
+		// Optimize the most common path - deduping is not needed here.
+		storeKeySet = index[indexedValues[0]]
+	} else {
+		// Need to de-dupe the return list.
+		// Since multiple keys are allowed, this can happen.
+		storeKeySet = sets.String{}
+		for _, indexedValue := range indexedValues {
+			for key := range index[indexedValue] {
+				storeKeySet.Insert(key)
+			}
+		}
+	}
+
+	list := make([]interface{}, 0, storeKeySet.Len())
+	for storeKey := range storeKeySet {
+		list = append(list, c.items[storeKey])
+	}
+	return list, nil
+}
+
+// ByIndex returns a list of the items whose indexed values in the given index include the given indexed value
+func (c *threadSafeMap) ByIndex(indexName, indexedValue string) ([]interface{}, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	indexFunc := c.indexers[indexName]
+	if indexFunc == nil {
+		return nil, fmt.Errorf("Index with name %s does not exist", indexName)
+	}
+
+	index := c.indices[indexName]
+
+	set := index[indexedValue]
+	list := make([]interface{}, 0, set.Len())
+	for key := range set {
+		list = append(list, c.items[key])
+	}
+
+	return list, nil
+}
+
+// IndexKeys returns a list of the Store keys of the objects whose indexed values in the given index include the given indexed value.
+// IndexKeys is thread-safe so long as you treat all items as immutable.
+func (c *threadSafeMap) IndexKeys(indexName, indexedValue string) ([]string, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	indexFunc := c.indexers[indexName]
+	if indexFunc == nil {
+		return nil, fmt.Errorf("Index with name %s does not exist", indexName)
+	}
+
+	index := c.indices[indexName]
+
+	set := index[indexedValue]
+	return set.List(), nil
+}
+
+func (c *threadSafeMap) ListIndexFuncValues(indexName string) []string {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	index := c.indices[indexName]
+	names := make([]string, 0, len(index))
+	for key := range index {
+		names = append(names, key)
+	}
+	return names
+}
+
+func (c *threadSafeMap) GetIndexers() Indexers {
+	return c.indexers
+}
+
+func (c *threadSafeMap) AddIndexers(newIndexers Indexers) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if len(c.items) > 0 {
+		return fmt.Errorf("cannot add indexers to running index")
+	}
+
+	oldKeys := sets.StringKeySet(c.indexers)
+	newKeys := sets.StringKeySet(newIndexers)
+
+	if oldKeys.HasAny(newKeys.List()...) {
+		return fmt.Errorf("indexer conflict: %v", oldKeys.Intersection(newKeys))
+	}
+
+	for k, v := range newIndexers {
+		c.indexers[k] = v
+	}
+	return nil
+}
+
+// updateIndices modifies the objects location in the managed indexes:
+// - for create you must provide only the newObj
+// - for update you must provide both the oldObj and the newObj
+// - for delete you must provide only the oldObj
+// updateIndices must be called from a function that already has a lock on the cache
+func (c *threadSafeMap) updateIndices(oldObj interface{}, newObj interface{}, key string) {
+	var oldIndexValues, indexValues []string
+	var err error
+	for name, indexFunc := range c.indexers {
+		if oldObj != nil {
+			oldIndexValues, err = indexFunc(oldObj)
+		} else {
+			oldIndexValues = oldIndexValues[:0]
+		}
+		if err != nil {
+			panic(fmt.Errorf("unable to calculate an index entry for key %q on index %q: %v", key, name, err))
+		}
+
+		if newObj != nil {
+			indexValues, err = indexFunc(newObj)
+		} else {
+			indexValues = indexValues[:0]
+		}
+		if err != nil {
+			panic(fmt.Errorf("unable to calculate an index entry for key %q on index %q: %v", key, name, err))
+		}
+
+		index := c.indices[name]
+		if index == nil {
+			index = Index{}
+			c.indices[name] = index
+		}
+
+		if len(indexValues) == 1 && len(oldIndexValues) == 1 && indexValues[0] == oldIndexValues[0] {
+			// We optimize for the most common case where indexFunc returns a single value which has not been changed
+			continue
+		}
+
+		for _, value := range oldIndexValues {
+			c.deleteKeyFromIndex(key, value, index)
+		}
+		for _, value := range indexValues {
+			c.addKeyToIndex(key, value, index)
+		}
+	}
+}
+
+func (c *threadSafeMap) addKeyToIndex(key, indexValue string, index Index) {
+	set := index[indexValue]
+	if set == nil {
+		set = sets.String{}
+		index[indexValue] = set
+	}
+	set.Insert(key)
+}
+
+func (c *threadSafeMap) deleteKeyFromIndex(key, indexValue string, index Index) {
+	set := index[indexValue]
+	if set == nil {
+		return
+	}
+	set.Delete(key)
+	// If we don't delete the set when zero, indices with high cardinality
+	// short lived resources can cause memory to increase over time from
+	// unused empty sets. See `kubernetes/kubernetes/issues/84959`.
+	if len(set) == 0 {
+		delete(index, indexValue)
+	}
+}
+
+func (c *threadSafeMap) Resync() error {
+	// Nothing to do
+	return nil
+}
+
+// NewThreadSafeStore creates a new instance of ThreadSafeStore.
+func NewThreadSafeStore(indexers Indexers, indices Indices) ThreadSafeStore {
+	return &threadSafeMap{
+		items:    map[string]interface{}{},
+		indexers: indexers,
+		indices:  indices,
+	}
+}

vendor/k8s.io/client-go/tools/cache/undelta_store.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2015 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 cache
+
+// UndeltaStore listens to incremental updates and sends complete state on every change.
+// It implements the Store interface so that it can receive a stream of mirrored objects
+// from Reflector.  Whenever it receives any complete (Store.Replace) or incremental change
+// (Store.Add, Store.Update, Store.Delete), it sends the complete state by calling PushFunc.
+// It is thread-safe.  It guarantees that every change (Add, Update, Replace, Delete) results
+// in one call to PushFunc, but sometimes PushFunc may be called twice with the same values.
+// PushFunc should be thread safe.
+type UndeltaStore struct {
+	Store
+	PushFunc func([]interface{})
+}
+
+// Assert that it implements the Store interface.
+var _ Store = &UndeltaStore{}
+
+// Add inserts an object into the store and sends complete state by calling PushFunc.
+// Note about thread safety.  The Store implementation (cache.cache) uses a lock for all methods.
+// In the functions below, the lock gets released and reacquired betweend the {Add,Delete,etc}
+// and the List.  So, the following can happen, resulting in two identical calls to PushFunc.
+// time            thread 1                  thread 2
+// 0               UndeltaStore.Add(a)
+// 1                                         UndeltaStore.Add(b)
+// 2               Store.Add(a)
+// 3                                         Store.Add(b)
+// 4               Store.List() -> [a,b]
+// 5                                         Store.List() -> [a,b]
+func (u *UndeltaStore) Add(obj interface{}) error {
+	if err := u.Store.Add(obj); err != nil {
+		return err
+	}
+	u.PushFunc(u.Store.List())
+	return nil
+}
+
+// Update sets an item in the cache to its updated state and sends complete state by calling PushFunc.
+func (u *UndeltaStore) Update(obj interface{}) error {
+	if err := u.Store.Update(obj); err != nil {
+		return err
+	}
+	u.PushFunc(u.Store.List())
+	return nil
+}
+
+// Delete removes an item from the cache and sends complete state by calling PushFunc.
+func (u *UndeltaStore) Delete(obj interface{}) error {
+	if err := u.Store.Delete(obj); err != nil {
+		return err
+	}
+	u.PushFunc(u.Store.List())
+	return nil
+}
+
+// Replace will delete the contents of current store, using instead the given list.
+// 'u' takes ownership of the list, you should not reference the list again
+// after calling this function.
+// The new contents complete state will be sent by calling PushFunc after replacement.
+func (u *UndeltaStore) Replace(list []interface{}, resourceVersion string) error {
+	if err := u.Store.Replace(list, resourceVersion); err != nil {
+		return err
+	}
+	u.PushFunc(u.Store.List())
+	return nil
+}
+
+// NewUndeltaStore returns an UndeltaStore implemented with a Store.
+func NewUndeltaStore(pushFunc func([]interface{}), keyFunc KeyFunc) *UndeltaStore {
+	return &UndeltaStore{
+		Store:    NewStore(keyFunc),
+		PushFunc: pushFunc,
+	}
+}