refact(deps): bump k8s and client-go deps to version v0.20.2 (#294)

Signed-off-by: prateekpandey14 <prateek.pandey@mayadata.io>

vendor/k8s.io/client-go/util/workqueue/delaying_queue.go

@@ -35,26 +35,37 @@ type DelayingInterface interface {
 
 // NewDelayingQueue constructs a new workqueue with delayed queuing ability
 func NewDelayingQueue() DelayingInterface {
-	return newDelayingQueue(clock.RealClock{}, "")
+	return NewDelayingQueueWithCustomClock(clock.RealClock{}, "")
 }
 
+// NewDelayingQueueWithCustomQueue constructs a new workqueue with ability to
+// inject custom queue Interface instead of the default one
+func NewDelayingQueueWithCustomQueue(q Interface, name string) DelayingInterface {
+	return newDelayingQueue(clock.RealClock{}, q, name)
+}
+
+// NewNamedDelayingQueue constructs a new named workqueue with delayed queuing ability
 func NewNamedDelayingQueue(name string) DelayingInterface {
-	return newDelayingQueue(clock.RealClock{}, name)
+	return NewDelayingQueueWithCustomClock(clock.RealClock{}, name)
 }
 
-func newDelayingQueue(clock clock.Clock, name string) DelayingInterface {
+// NewDelayingQueueWithCustomClock constructs a new named workqueue
+// with ability to inject real or fake clock for testing purposes
+func NewDelayingQueueWithCustomClock(clock clock.Clock, name string) DelayingInterface {
+	return newDelayingQueue(clock, NewNamed(name), name)
+}
+
+func newDelayingQueue(clock clock.Clock, q Interface, name string) *delayingType {
 	ret := &delayingType{
-		Interface:         NewNamed(name),
-		clock:             clock,
-		heartbeat:         clock.NewTicker(maxWait),
-		stopCh:            make(chan struct{}),
-		waitingForAddCh:   make(chan *waitFor, 1000),
-		metrics:           newRetryMetrics(name),
-		deprecatedMetrics: newDeprecatedRetryMetrics(name),
+		Interface:       q,
+		clock:           clock,
+		heartbeat:       clock.NewTicker(maxWait),
+		stopCh:          make(chan struct{}),
+		waitingForAddCh: make(chan *waitFor, 1000),
+		metrics:         newRetryMetrics(name),
 	}
 
 	go ret.waitingLoop()
-
 	return ret
 }
 
@@ -77,8 +88,7 @@ type delayingType struct {
 	waitingForAddCh chan *waitFor
 
 	// metrics counts the number of retries
-	metrics           retryMetrics
-	deprecatedMetrics retryMetrics
+	metrics retryMetrics
 }
 
 // waitFor holds the data to add and the time it should be added
@@ -154,7 +164,6 @@ func (q *delayingType) AddAfter(item interface{}, duration time.Duration) {
 	}
 
 	q.metrics.retry()
-	q.deprecatedMetrics.retry()
 
 	// immediately add things with no delay
 	if duration <= 0 {
@@ -181,6 +190,9 @@ func (q *delayingType) waitingLoop() {
 	// Make a placeholder channel to use when there are no items in our list
 	never := make(<-chan time.Time)
 
+	// Make a timer that expires when the item at the head of the waiting queue is ready
+	var nextReadyAtTimer clock.Timer
+
 	waitingForQueue := &waitForPriorityQueue{}
 	heap.Init(waitingForQueue)
 
@@ -208,8 +220,12 @@ func (q *delayingType) waitingLoop() {
 		// Set up a wait for the first item's readyAt (if one exists)
 		nextReadyAt := never
 		if waitingForQueue.Len() > 0 {
+			if nextReadyAtTimer != nil {
+				nextReadyAtTimer.Stop()
+			}
 			entry := waitingForQueue.Peek().(*waitFor)
-			nextReadyAt = q.clock.After(entry.readyAt.Sub(now))
+			nextReadyAtTimer = q.clock.NewTimer(entry.readyAt.Sub(now))
+			nextReadyAt = nextReadyAtTimer.C()
 		}
 
 		select {