rebase: update vault/api to v1.1.1

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/github.com/cenkalti/backoff/v3/ticker.go

@@ -0,0 +1,82 @@
+package backoff
+
+import (
+	"sync"
+	"time"
+)
+
+// Ticker holds a channel that delivers `ticks' of a clock at times reported by a BackOff.
+//
+// Ticks will continue to arrive when the previous operation is still running,
+// so operations that take a while to fail could run in quick succession.
+type Ticker struct {
+	C        <-chan time.Time
+	c        chan time.Time
+	b        BackOffContext
+	stop     chan struct{}
+	stopOnce sync.Once
+}
+
+// NewTicker returns a new Ticker containing a channel that will send
+// the time at times specified by the BackOff argument. Ticker is
+// guaranteed to tick at least once.  The channel is closed when Stop
+// method is called or BackOff stops. It is not safe to manipulate the
+// provided backoff policy (notably calling NextBackOff or Reset)
+// while the ticker is running.
+func NewTicker(b BackOff) *Ticker {
+	c := make(chan time.Time)
+	t := &Ticker{
+		C:    c,
+		c:    c,
+		b:    ensureContext(b),
+		stop: make(chan struct{}),
+	}
+	t.b.Reset()
+	go t.run()
+	return t
+}
+
+// Stop turns off a ticker. After Stop, no more ticks will be sent.
+func (t *Ticker) Stop() {
+	t.stopOnce.Do(func() { close(t.stop) })
+}
+
+func (t *Ticker) run() {
+	c := t.c
+	defer close(c)
+
+	// Ticker is guaranteed to tick at least once.
+	afterC := t.send(time.Now())
+
+	for {
+		if afterC == nil {
+			return
+		}
+
+		select {
+		case tick := <-afterC:
+			afterC = t.send(tick)
+		case <-t.stop:
+			t.c = nil // Prevent future ticks from being sent to the channel.
+			return
+		case <-t.b.Context().Done():
+			return
+		}
+	}
+}
+
+func (t *Ticker) send(tick time.Time) <-chan time.Time {
+	select {
+	case t.c <- tick:
+	case <-t.stop:
+		return nil
+	}
+
+	next := t.b.NextBackOff()
+	if next == Stop {
+		t.Stop()
+		return nil
+	}
+
+	return time.After(next)
+}