project init

util/retry.go

@@ -0,0 +1,32 @@
+package util
+
+import (
+	"math/rand"
+	"time"
+)
+
+// Retries a given toExec function calling onError on failed attempts
+// onError shouldn be a lightweight function and shouldn't be blocking
+func Retry(attempts int, sleep time.Duration, toExec func() error, onError func(e error)) error {
+	if err := toExec(); err != nil {
+		if s, ok := err.(stop); ok {
+			return s.error
+		}
+
+		if attempts--; attempts > 0 {
+			jitter := time.Duration(rand.Int63n(int64(sleep)))
+			sleep = sleep + jitter/2
+
+			onError(err)
+			time.Sleep(sleep)
+			return Retry(attempts, 2*sleep, toExec, onError)
+		}
+		return err
+	}
+
+	return nil
+}
+
+type stop struct {
+	error
+}