vendor c/image v5.4.2

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/vbauerster/mpb/v5/priority_queue.go

@@ -0,0 +1,32 @@
+package mpb
+
+// A priorityQueue implements heap.Interface
+type priorityQueue []*Bar
+
+func (pq priorityQueue) Len() int { return len(pq) }
+
+func (pq priorityQueue) Less(i, j int) bool {
+	return pq[i].priority < pq[j].priority
+}
+
+func (pq priorityQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *priorityQueue) Push(x interface{}) {
+	s := *pq
+	bar := x.(*Bar)
+	bar.index = len(s)
+	s = append(s, bar)
+	*pq = s
+}
+
+func (pq *priorityQueue) Pop() interface{} {
+	s := *pq
+	*pq = s[0 : len(s)-1]
+	bar := s[len(s)-1]
+	bar.index = -1 // for safety
+	return bar
+}