1. Fix lint errors for the whole directory staging/src/k8s.io/client-go/tools/cache;

2. Remove staging/src/k8s.io/client-go/tools/cache from .golint_failures;
3. Fix some typo from comments.

Kubernetes-commit: 0e0e1f7daba0a6ae6dd59df0a1bb643c323ad8cb

tools/cache/controller.go

@@ -79,6 +79,7 @@ type controller struct {
 	clock          clock.Clock
 }
 
+// Controller is a generic controller framework.
 type Controller interface {
 	Run(stopCh <-chan struct{})
 	HasSynced() bool
@@ -149,7 +150,7 @@ func (c *controller) processLoop() {
 	for {
 		obj, err := c.config.Queue.Pop(PopProcessFunc(c.config.Process))
 		if err != nil {
-			if err == FIFOClosedError {
+			if err == ErrFIFOClosed {
 				return
 			}
 			if c.config.RetryOnError {

tools/cache/delta_fifo.go

@@ -160,7 +160,7 @@ func (f *DeltaFIFO) KeyOf(obj interface{}) (string, error) {
 	return f.keyFunc(obj)
 }
 
-// Return true if an Add/Update/Delete/AddIfNotPresent are called first,
+// HasSynced returns true if an Add/Update/Delete/AddIfNotPresent are called first,
 // or an Update called first but the first batch of items inserted by Replace() has been popped
 func (f *DeltaFIFO) HasSynced() bool {
 	f.lock.Lock()
@@ -389,7 +389,7 @@ func (f *DeltaFIFO) GetByKey(key string) (item interface{}, exists bool, err err
 	return d, exists, nil
 }
 
-// Checks if the queue is closed
+// IsClosed checks if the queue is closed
 func (f *DeltaFIFO) IsClosed() bool {
 	f.closedLock.Lock()
 	defer f.closedLock.Unlock()
@@ -417,7 +417,7 @@ func (f *DeltaFIFO) Pop(process PopProcessFunc) (interface{}, error) {
 			// 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.IsClosed() {
-				return nil, FIFOClosedError
+				return nil, ErrFIFOClosed
 			}
 
 			f.cond.Wait()
@@ -593,6 +593,7 @@ type KeyGetter interface {
 // DeltaType is the type of a change (addition, deletion, etc)
 type DeltaType string
 
+// Change type definition
 const (
 	Added   DeltaType = "Added"
 	Updated DeltaType = "Updated"

tools/cache/expiration_cache.go

@@ -55,7 +55,7 @@ type ExpirationPolicy interface {
 type TTLPolicy struct {
 	//	 >0: Expire entries with an age > ttl
 	//	<=0: Don't expire any entry
-	Ttl time.Duration
+	TTL time.Duration
 
 	// Clock used to calculate ttl expiration
 	Clock clock.Clock
@@ -64,7 +64,7 @@ type TTLPolicy struct {
 // 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
+	return p.TTL > 0 && p.Clock.Since(obj.Timestamp) > p.TTL
 }
 
 // TimestampedEntry is the only type allowed in a ExpirationCache.

tools/cache/expiration_cache_fakes.go

@@ -33,16 +33,19 @@ func (c *fakeThreadSafeMap) Delete(key string) {
 	}
 }
 
+// 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{

tools/cache/expiration_cache_test.go

@@ -181,7 +181,7 @@ func TestTTLPolicy(t *testing.T) {
 		t.Errorf("TTL Cache should expire entries older than ttl")
 	}
 	for _, ttl = range []time.Duration{0, -1} {
-		policy.Ttl = ttl
+		policy.TTL = ttl
 		if policy.IsExpired(fakeTimestampedEntry) {
 			t.Errorf("TTL policy should only expire entries when initialized with a ttl > 0")
 		}

tools/cache/fake_custom_store.go

@@ -16,7 +16,7 @@ limitations under the License.
 
 package cache
 
-// FakeStore lets you define custom functions for store operations
+// FakeCustomStore lets you define custom functions for store operations.
 type FakeCustomStore struct {
 	AddFunc      func(obj interface{}) error
 	UpdateFunc   func(obj interface{}) error

tools/cache/fifo.go

@@ -34,7 +34,8 @@ type ErrRequeue struct {
 	Err error
 }
 
-var FIFOClosedError error = errors.New("DeltaFIFO: manipulating with closed queue")
+// ErrFIFOClosed used when FIFO is closed
+var ErrFIFOClosed = errors.New("DeltaFIFO: manipulating with closed queue")
 
 func (e ErrRequeue) Error() string {
 	if e.Err == nil {
@@ -66,7 +67,7 @@ type Queue interface {
 	Close()
 }
 
-// Helper function for popping from Queue.
+// 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{} {
@@ -126,7 +127,7 @@ func (f *FIFO) Close() {
 	f.cond.Broadcast()
 }
 
-// Return true if an Add/Update/Delete/AddIfNotPresent are called first,
+// HasSynced returns true if an Add/Update/Delete/AddIfNotPresent are called first,
 // or an Update called first but the first batch of items inserted by Replace() has been popped
 func (f *FIFO) HasSynced() bool {
 	f.lock.Lock()
@@ -242,7 +243,7 @@ func (f *FIFO) GetByKey(key string) (item interface{}, exists bool, err error) {
 	return item, exists, nil
 }
 
-// Checks if the queue is closed
+// IsClosed checks if the queue is closed
 func (f *FIFO) IsClosed() bool {
 	f.closedLock.Lock()
 	defer f.closedLock.Unlock()
@@ -267,7 +268,7 @@ func (f *FIFO) Pop(process PopProcessFunc) (interface{}, error) {
 			// 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.IsClosed() {
-				return nil, FIFOClosedError
+				return nil, ErrFIFOClosed
 			}
 
 			f.cond.Wait()

tools/cache/heap.go

@@ -28,7 +28,9 @@ 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.
@@ -158,7 +160,7 @@ func (h *Heap) Add(obj interface{}) error {
 	return nil
 }
 
-// Adds all the items in the list to the queue and then signals the condition
+// 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 {
@@ -249,11 +251,11 @@ func (h *Heap) Pop() (interface{}, error) {
 		h.cond.Wait()
 	}
 	obj := heap.Pop(h.data)
-	if obj != nil {
+	if obj == nil {
-		return obj, nil
-	} else {
 		return nil, fmt.Errorf("object was removed from heap data")
 	}
+
+	return obj, nil
 }
 
 // List returns a list of all the items.

tools/cache/index.go

@@ -75,6 +75,7 @@ func IndexFuncToKeyFuncAdapter(indexFunc IndexFunc) KeyFunc {
 }
 
 const (
+	// NamespaceIndex is the lookup name for the most comment index function, which is to index by the namespace field.
 	NamespaceIndex string = "namespace"
 )
 

tools/cache/listers.go

@@ -30,6 +30,7 @@ import (
 // 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() {
@@ -50,6 +51,7 @@ func ListAll(store Store, selector labels.Selector, appendFn AppendFunc) error {
 	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 {
@@ -124,6 +126,7 @@ type GenericNamespaceLister interface {
 	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}
 }

tools/cache/mutation_cache.go

@@ -42,6 +42,7 @@ type MutationCache interface {
 	Mutation(interface{})
 }
 
+// ResourceVersionComparator is able to compare object versions.
 type ResourceVersionComparator interface {
 	CompareResourceVersion(lhs, rhs runtime.Object) int
 }

tools/cache/mutation_detector.go

@@ -36,12 +36,14 @@ func init() {
 	mutationDetectionEnabled, _ = strconv.ParseBool(os.Getenv("KUBE_CACHE_MUTATION_DETECTOR"))
 }
 
-type CacheMutationDetector interface {
+// MutationDetector is able to monitor if the object be modified outside.
+type MutationDetector interface {
 	AddObject(obj interface{})
 	Run(stopCh <-chan struct{})
 }
 
-func NewCacheMutationDetector(name string) CacheMutationDetector {
+// NewCacheMutationDetector creates a new instance for the defaultCacheMutationDetector.
+func NewCacheMutationDetector(name string) MutationDetector {
 	if !mutationDetectionEnabled {
 		return dummyMutationDetector{}
 	}

tools/cache/shared_informer.go

@@ -34,7 +34,7 @@ import (
 // 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, and name.  One SharedInfomer provides linkage to objects
+// namespace, and name.  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 and/or by label selector and/or field selector.
@@ -44,7 +44,7 @@ import (
 // A state is either "absent" or present with a ResourceVersion and
 // other appropriate content.
 //
-// A SharedInformer maintains a local cache, exposed by Store(), of
+// A SharedInformer maintains a local cache, exposed by GetStore(), 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
@@ -67,10 +67,10 @@ import (
 // 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 emnds, or communication
+// too soon, the authoritative state service ends, or communication
 // problems persistently thwart the desired result).
 //
-// The keys in Store() are of the form namespace/name for namespaced
+// The keys in GetStore() are of the form namespace/name for namespaced
 // objects, and are simply the name for non-namespaced objects.
 //
 // A client is identified here by a ResourceEventHandler.  For every
@@ -116,6 +116,7 @@ type SharedInformer interface {
 	LastSyncResourceVersion() string
 }
 
+// SharedIndexInformer provides add and get Indexers ability based on SharedInformer.
 type SharedIndexInformer interface {
 	SharedInformer
 	// AddIndexers add indexers to the informer before it starts.
@@ -182,7 +183,7 @@ type sharedIndexInformer struct {
 	controller Controller
 
 	processor             *sharedProcessor
-	cacheMutationDetector CacheMutationDetector
+	cacheMutationDetector MutationDetector
 
 	// This block is tracked to handle late initialization of the controller
 	listerWatcher ListerWatcher
@@ -222,7 +223,7 @@ func (v *dummyController) HasSynced() bool {
 	return v.informer.HasSynced()
 }
 
-func (c *dummyController) LastSyncResourceVersion() string {
+func (v *dummyController) LastSyncResourceVersion() string {
 	return ""
 }
 

tools/cache/thread_safe_store.go

@@ -302,6 +302,7 @@ func (c *threadSafeMap) Resync() error {
 	return nil
 }
 
+// NewThreadSafeStore creates a new instance of ThreadSafeStore.
 func NewThreadSafeStore(indexers Indexers, indices Indices) ThreadSafeStore {
 	return &threadSafeMap{
 		items:    map[string]interface{}{},

tools/cache/undelta_store.go

@@ -31,6 +31,7 @@ type UndeltaStore struct {
 // 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.
@@ -41,7 +42,6 @@ var _ Store = &UndeltaStore{}
 // 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
@@ -50,6 +50,7 @@ func (u *UndeltaStore) Add(obj interface{}) error {
 	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
@@ -58,6 +59,7 @@ func (u *UndeltaStore) Update(obj interface{}) error {
 	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
@@ -66,6 +68,10 @@ func (u *UndeltaStore) Delete(obj interface{}) error {
 	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

tools/cache/undelta_store_test.go

@@ -47,7 +47,7 @@ func TestUpdateCallsPush(t *testing.T) {
 	}
 
 	var got []interface{}
-	var callcount int = 0
+	var callcount = 0
 	push := func(m []interface{}) {
 		callcount++
 		got = m
@@ -73,7 +73,7 @@ func TestDeleteCallsPush(t *testing.T) {
 	}
 
 	var got []interface{}
-	var callcount int = 0
+	var callcount = 0
 	push := func(m []interface{}) {
 		callcount++
 		got = m
@@ -110,7 +110,7 @@ func TestReplaceCallsPush(t *testing.T) {
 	}
 
 	var got []interface{}
-	var callcount int = 0
+	var callcount = 0
 	push := func(m []interface{}) {
 		callcount++
 		got = m