My favorite #golang retry function-蒲公英云

My favorite #golang retry function

func retry(attempts int, sleep time.Duration, callback func() error) (err error) {
    for i := 0; ; i++ {
        err = callback()
        if err == nil {
            return
        }
        if i >= (attempts - 1) {
            break
        }
        time.Sleep(sleep)
        log.Println("retrying after error:", err)
    }
    return fmt.Errorf("after %d attempts, last error: %s", attempts, err)
}
func retryDuring(duration time.Duration, sleep time.Duration, callback func() error) (err error) {
    t0 := time.Now()
    i := 0
    for {
        i++
        err = callback()
        if err == nil {
            return
        }
        delta := time.Now().Sub(t0)
        if delta > duration {
            return fmt.Errorf("after %d attempts (during %s), last error: %s", i, delta, err)
        }
        time.Sleep(sleep)
        log.Println("retrying after error:", err)
    }
}

use

var signedContent []byte
        err := retry(5, 2*time.Second, func() (err error) {
            signedContent, err = signFile(unsignedFile, contents)
            return
        })
        if err != nil {
            log.Println(err)
            http.Error(w, err.Error(), 500)
            return
        }