Refactor delta addition/clearing

staging/src/k8s.io/client-go/tools/cache/the_real_fifo.go

@@ -282,6 +282,11 @@ func (f *RealFIFO) PopBatch(process ProcessBatchFunc) error {
 	isInInitialList := !f.hasSynced_locked()
 	unique := sets.NewString()
 	deltas := make([]Delta, 0, min(len(f.items), f.batchSize))
+	moveDeltaToProcessList := func(i int) {
+		deltas = append(deltas, f.items[i])
+		// The underlying array still exists and references this object, so the object will not be garbage collected unless we zero the reference.
+		f.items[i] = Delta{}
+	}
 	// only bundle unique items into a batch
 	for i := 0; i < f.batchSize && i < len(f.items); i++ {
 		if f.initialPopulationCount > 0 && i >= f.initialPopulationCount {
@@ -295,18 +300,14 @@ func (f *RealFIFO) PopBatch(process ProcessBatchFunc) error {
 			// still pop the broken item out of queue to be compatible with the non-batch behavior it should be safe
 			// when 1st element is broken, however for Nth broken element, there's possible risk that broken item
 			// still can be processed and broke the uniqueness of the batch unexpectedly.
-			deltas = append(deltas, item)
-			// The underlying array still exists and references this object, so the object will not be garbage collected unless we zero the reference.
-			f.items[i] = Delta{}
+			moveDeltaToProcessList(i)
 			break
 		}
 		if unique.Has(id) {
 			break
 		}
 		unique.Insert(id)
-		deltas = append(deltas, item)
-		// The underlying array still exists and references this object, so the object will not be garbage collected unless we zero the reference.
-		f.items[i] = Delta{}
+		moveDeltaToProcessList(i)
 	}
 	if f.initialPopulationCount > 0 {
 		f.initialPopulationCount -= len(deltas)