rebase: update kubernetes to v1.20.0

updated kubernetes packages to latest
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

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

@@ -25,39 +25,77 @@ import (
 
 type DoWorkPieceFunc func(piece int)
 
+type options struct {
+	chunkSize int
+}
+
+type Options func(*options)
+
+// WithChunkSize allows to set chunks of work items to the workers, rather than
+// processing one by one.
+// It is recommended to use this option if the number of pieces significantly
+// higher than the number of workers and the work done for each item is small.
+func WithChunkSize(c int) func(*options) {
+	return func(o *options) {
+		o.chunkSize = c
+	}
+}
+
 // ParallelizeUntil is a framework that allows for parallelizing N
 // independent pieces of work until done or the context is canceled.
-func ParallelizeUntil(ctx context.Context, workers, pieces int, doWorkPiece DoWorkPieceFunc) {
-	var stop <-chan struct{}
-	if ctx != nil {
-		stop = ctx.Done()
+func ParallelizeUntil(ctx context.Context, workers, pieces int, doWorkPiece DoWorkPieceFunc, opts ...Options) {
+	if pieces == 0 {
+		return
+	}
+	o := options{}
+	for _, opt := range opts {
+		opt(&o)
+	}
+	chunkSize := o.chunkSize
+	if chunkSize < 1 {
+		chunkSize = 1
 	}
 
-	toProcess := make(chan int, pieces)
-	for i := 0; i < pieces; i++ {
+	chunks := ceilDiv(pieces, chunkSize)
+	toProcess := make(chan int, chunks)
+	for i := 0; i < chunks; i++ {
 		toProcess <- i
 	}
 	close(toProcess)
 
-	if pieces < workers {
-		workers = pieces
+	var stop <-chan struct{}
+	if ctx != nil {
+		stop = ctx.Done()
+	}
+	if chunks < workers {
+		workers = chunks
 	}
-
 	wg := sync.WaitGroup{}
 	wg.Add(workers)
 	for i := 0; i < workers; i++ {
 		go func() {
 			defer utilruntime.HandleCrash()
 			defer wg.Done()
-			for piece := range toProcess {
-				select {
-				case <-stop:
-					return
-				default:
-					doWorkPiece(piece)
+			for chunk := range toProcess {
+				start := chunk * chunkSize
+				end := start + chunkSize
+				if end > pieces {
+					end = pieces
+				}
+				for p := start; p < end; p++ {
+					select {
+					case <-stop:
+						return
+					default:
+						doWorkPiece(p)
+					}
 				}
 			}
 		}()
 	}
 	wg.Wait()
 }
+
+func ceilDiv(a, b int) int {
+	return (a + b - 1) / b
+}