retry

Documentation

Overview

Package retry is for executing a function repeatedly until it was successful or canceled by the context.

Index

• Constants
• func Retry(retryFunc RetryFunc, opts ...Option) error
• type BackoffStrategy
• type Option
  • func Context(ctx context.Context) Option
  • func RetryTimes(n uint) Option
  • func RetryWithCustomBackoff(backoffStrategy BackoffStrategy) Option
  • func RetryWithExponentialWithJitterBackoff(interval time.Duration, base uint64, maxJitter time.Duration) Option
  • func RetryWithLinearBackoff(interval time.Duration) Option
• type RetryConfig
• type RetryFunc

Examples

• Context
• Retry
• RetryTimes
• RetryWithCustomBackoff
• RetryWithExponentialWithJitterBackoff
• RetryWithLinearBackoff

Constants

const (
	// DefaultRetryTimes times of retry
	DefaultRetryTimes = 5
	// DefaultRetryDuration time duration of two retries
	DefaultRetryLinearInterval = time.Second * 3
)

Functions

func Retry

func Retry(retryFunc RetryFunc, opts ...Option) error

Retry executes the retryFunc repeatedly until it was successful or canceled by the context The default times of retries is 5 and the default duration between retries is 3 seconds. Play: https://go.dev/play/p/nk2XRmagfVF

Example

number := 0
increaseNumber := func() error {
	number++
	if number == 3 {
		return nil
	}
	return errors.New("error occurs")
}

err := Retry(increaseNumber, RetryWithLinearBackoff(time.Microsecond*50))
if err != nil {
	return
}

fmt.Println(number)

Output:

3

Types

type BackoffStrategy

type BackoffStrategy interface {
	// CalculateInterval returns the time.Duration after which the next retry attempt should be made.
	CalculateInterval() time.Duration
}

BackoffStrategy is an interface that defines a method for calculating backoff intervals.

type Option

type Option func(*RetryConfig)

Option is for adding retry config

func Context

func Context(ctx context.Context) Option

Context set retry context config. Play: https://go.dev/play/p/xnAOOXv9GkS

Example

ctx, cancel := context.WithCancel(context.TODO())

number := 0
increaseNumber := func() error {
	number++
	if number > 3 {
		cancel()
	}
	return errors.New("error occurs")
}

Retry(increaseNumber,
	RetryWithLinearBackoff(time.Microsecond*50),
	Context(ctx),
)

fmt.Println(number)

Output:

4

func RetryTimes

func RetryTimes(n uint) Option

RetryTimes set times of retry. Play: https://go.dev/play/p/ssfVeU2SwLO

Example

number := 0

increaseNumber := func() error {
	number++
	if number == 3 {
		return nil
	}
	return errors.New("error occurs")
}

err := Retry(increaseNumber, RetryTimes(2))
if err != nil {
	fmt.Println(err)
}

Output:

function retry.ExampleRetryTimes.func1 run failed after 2 times retry

func RetryWithCustomBackoff

func RetryWithCustomBackoff(backoffStrategy BackoffStrategy) Option

RetryWithCustomBackoff set abitary custom backoff strategy Play: todo

Example

number := 0
increaseNumber := func() error {
	number++
	if number == 3 {
		return nil
	}
	return errors.New("error occurs")
}

err := Retry(increaseNumber, RetryWithCustomBackoff(&ExampleCustomBackoffStrategy{interval: time.Microsecond * 50}))
if err != nil {
	return
}

fmt.Println(number)

Output:

3

func RetryWithExponentialWithJitterBackoff

func RetryWithExponentialWithJitterBackoff(interval time.Duration, base uint64, maxJitter time.Duration) Option

RetryWithExponentialWithJitterBackoff set exponential strategy backoff Play: todo

Example

number := 0
increaseNumber := func() error {
	number++
	if number == 3 {
		return nil
	}
	return errors.New("error occurs")
}

err := Retry(increaseNumber, RetryWithExponentialWithJitterBackoff(time.Microsecond*50, 2, time.Microsecond*25))
if err != nil {
	return
}

fmt.Println(number)

Output:

3

func RetryWithLinearBackoff

func RetryWithLinearBackoff(interval time.Duration) Option

RetryWithLinearBackoff set linear strategy backoff Play: todo

Example

number := 0
increaseNumber := func() error {
	number++
	if number == 3 {
		return nil
	}
	return errors.New("error occurs")
}

err := Retry(increaseNumber, RetryWithLinearBackoff(time.Microsecond*50))
if err != nil {
	return
}

fmt.Println(number)

Output:

3

type RetryConfig

type RetryConfig struct {
	// contains filtered or unexported fields
}

RetryConfig is config for retry

type RetryFunc

type RetryFunc func() error

RetryFunc is function that retry executes