Retry

Overview

The utils package provides a retry mechanism for executing functions that may fail, with automatic panic recovery and configurable retry attempts.

API Reference

RetryWork(work func() (any, error), retryTimes int) (any, error)

Executes a work function, catching panics or errors, and retries up to retryTimes times.

Parameters:

• work: The function to execute
• retryTimes: Maximum number of retries (not including the first attempt)

Returns:

• The data returned by the work function
• Any error encountered (returns after exhausting all retries)

func RetryWork(work func() (any, error), retryTimes int) (any, error)

Example

package main

import (
	"fmt"
	"math/rand"
	"time"

	"github.com/leoheung/go-patterns/utils"
)

func main() {
	// Simulate a function that may fail
	attempt := 0
	work := func() (any, error) {
		attempt++
		// Simulate random failure (70% chance of failure)
		if rand.Float32() < 0.7 {
			return nil, fmt.Errorf("operation failed on attempt %d", attempt)
		}
		return fmt.Sprintf("Success on attempt %d", attempt), nil
	}

	// Retry up to 3 times (4 total attempts)
	result, err := utils.RetryWork(work, 3)

	if err != nil {
		fmt.Printf("Final error: %v\n", err)
	} else {
		fmt.Printf("Result: %v\n", result)
	}
}

Retry Behavior

1. Executes the work function
2. If successful, returns immediately
3. If failed (error or panic):
   • Logs the failure
   • If retries remaining, sleeps 500ms and retries
   • If no retries remaining, returns the error
4. Automatically recovers from panics and treats them as errors

Notes

• Panics are automatically recovered and converted to errors
• A 500ms delay is inserted between retries
• All attempts (including failures) are logged
• The function is thread-safe when used with proper synchronization