clone from danieldin95

pkg/libol/promise.go

@@ -0,0 +1,41 @@
+package libol
+
+import "time"
+
+type Promise struct {
+	Count  int
+	MaxTry int
+	First  time.Duration // the delay time.
+	MinInt time.Duration // the normal time.
+	MaxInt time.Duration // the max delay time.
+}
+
+func NewPromise(first, min, max time.Duration) *Promise {
+	return &Promise{
+		First:  first,
+		MaxInt: max,
+		MinInt: min,
+	}
+}
+
+func (p *Promise) Done(call func() error) {
+	for {
+		p.Count++
+		if p.MaxTry > 0 && p.Count > p.MaxTry {
+			return
+		}
+		if err := call(); err == nil {
+			return
+		}
+		time.Sleep(p.First)
+		if p.First < p.MaxInt {
+			p.First += p.MinInt
+		}
+	}
+}
+
+func (p *Promise) Go(call func() error) {
+	Go(func() {
+		p.Done(call)
+	})
+}