Retrier

Retrier is a small package that makes retrying anything easier with custom or predefined retry functions.

Usage

Create a retrier by providing an upper limit to retries and a delay function.

ret := retrier.NewRetrier(
    10, // -1 for no limit
    retrier.ConstantDelay(time.Second),
)

You can use one of the predefined delay functions, or provide your own.

ret := retrier.NewRetrier(
    -1,
    func(count int) time.Duration {
        m := rand.Intn(60)
        return time.Second * time.Duration(m)
    },
)

Use the Run or RunCtx functions to run any task. The retrier will retry the task if it returns true ("should retry"). The retrier will not retry the task if it returns false ("should not retry"), if the retry cap is reached or if the context is canceled.

ret.RunCtx(
    context.TODO(),
    func(ctx context.Context) (error, bool) {
        resp, err := http.Get("https://some-api.com")
        if err != nil {
            fmt.Println("request failed")
            return err, true
        } else {
            fmt.Println(resp)
            return nil, false
        }
    },
)

Delay Functions

Function	Delay	Example
No Delay	0	0, 0, 0, 0, 0
Constant Delay	c	1, 1, 1, 1, 1
Linear Delay	r*c	1, 2, 3, 4, 5
Capped Linear Delay	min(r*c, cap)	1, 2, 3, 3, 3
Exponential Delay	a*b^r	2, 4, 8, 16, 32
Capped Exponential Delay	min(a*b^r, cap)	2, 4, 8, 10, 10