repeat

Repeat

The repeat package provides powerful and flexible retry logic for operations that may intermittently fail. It supports exponential backoff, jitter, advanced retry policies, and integration with contexts for cancellation.

Features

• 🔁 Automatic retries with context awareness
• 📈 Optional exponential backoff with jitter
• 🧠 Customizable error filters and retry policies
• ⌛ Safe retry limits by count or duration
• 🕸️ Plug-and-play HTTP and WebSocket examples

Installation

go get github.com/yourusername/repeat

Quick Start

Basic Retry Logic

err := repeat.Exec(ctx, func(ctx context.Context, attempt int) error {
	return trySomething() // return nil on success
})

Functional Options

• Customize behavior with options:

err := repeat.Exec(
	ctx,
	myOperation,
	repeat.WithMaxAttempts(5),
	repeat.WithMinWait(500*time.Millisecond),
	repeat.WithExponentialBackoff(300*time.Millisecond, 5*time.Second),
	repeat.WithJitter(repeat.FullJitter),
)

Full Example: HTTP Retry Client

client := repeat.NewClient(nil, repeat.WithMaxAttempts(3))

req, _ := http.NewRequest("GET", "https://api.example.com", nil)
resp, err := client.Do(req)

• Automatically retries failed 5xx responses using exponential backoff and jitter.

Full Example: WebSocket Retry Dialer

conn, err := repeat.ConnectWithRetry(ctx, func(ctx context.Context) (*websocket.Conn, error) {
	return websocket.DefaultDialer.DialContext(ctx, "wss://echo.websocket.org", nil)
})

Advanced Retry Policies

• Use custom retry logic:

repeat.WithRetryPolicy(func(retryCount int, err error) bool {
	return retryCount < 5 && errors.Is(err, io.ErrUnexpectedEOF)
})

• Or basic filters:

repeat.WithErrorFilter(func(err error) bool {
	return strings.Contains(err.Error(), "timeout")
})

Jitter Utilities

Full Jitter

repeat.WithJitter(repeat.FullJitter) // Randomizes full delay window

• Define your own jitter logic:

repeat.WithJitter(func(d time.Duration) time.Duration {
	return time.Duration(float64(d) * 0.5) // 50% jitter
})

Constants

Errors

• If MaxAttempts is reached: returns the last error wrapped with retry context.
• If context is cancelled: returns context.Canceled or context.DeadlineExceeded.
• Retry policies can short-circuit retries before limits are hit.

📝 License

• MIT License – © Raman Zaitsau (@jwm1rr0rb)

🙌 Contributions

• PRs and suggestions welcome! Feel free to fork, open issues, or create a pull request 🚀

• Let me know if you want badges, a table of contents, or markdown export to file!