retry

Documentation

Index

• Constants
• type Backoff
  • func NewConstant(t time.Duration) Backoff
  • func NewExponential(base time.Duration) Backoff
  • func NewFibonacci(base time.Duration) Backoff
  • func NewNoop() Backoff
  • func WithCappedDuration(cap time.Duration, next Backoff) Backoff
  • func WithJitter(j time.Duration, next Backoff) Backoff
  • func WithJitterPercent(j uint64, next Backoff) Backoff
  • func WithMaxDuration(timeout time.Duration, next Backoff) Backoff
  • func WithMaxRetries(max uint32, next Backoff) Backoff
• type BackoffFunc
  • func (b BackoffFunc) Next() (time.Duration, bool)
• type Retry
  • func Default() Retry
  • func New(bs ...Backoff) Retry
  • func (d Retry) Do(f func(i int) error) (err error)
  • func (d Retry) DoVal(f func(i int) (interface{}, error)) (val interface{}, err error)

Constants

const DefaultConstant = time.Second

Types

type Backoff

type Backoff interface {
	// Next returns the time duration to wait and whether to stop.
	Next() (next time.Duration, stop bool)
}

Backoff is an interface that backs off.

func NewConstant

func NewConstant(t time.Duration) Backoff

NewConstant creates a new constant backoff using the value t.

func NewExponential

func NewExponential(base time.Duration) Backoff

NewExponential creates a new exponential backoff using the starting value of base and doubling on each failure (1, 2, 4, 8, 16, 32, 64...), up to max. It's very efficient, but does not check for overflow, so ensure you bound the retry.

func NewFibonacci

func NewFibonacci(base time.Duration) Backoff

NewFibonacci creates a new Fibonacci backoff using the starting value of base. The wait time is the sum of the previous two wait times on each failed attempt (1, 1, 2, 3, 5, 8, 13...).

func NewNoop

func NewNoop() Backoff

NewNoop creates a new noop backoff

func WithCappedDuration

func WithCappedDuration(cap time.Duration, next Backoff) Backoff

WithCappedDuration sets a maximum on the duration returned from the next backoff. This is NOT a total backoff time, but rather a cap on the maximum value a backoff can return. Without another middleware, the backoff will continue infinitely.

func WithJitter

func WithJitter(j time.Duration, next Backoff) Backoff

WithJitter wraps a backoff function and adds the specified jitter. j can be interpreted as "+/- j". For example, if j were 5 seconds and the backoff returned 20s, the value could be between 15 and 25 seconds. The value can never be less than 0.

func WithJitterPercent

func WithJitterPercent(j uint64, next Backoff) Backoff

WithJitterPercent wraps a backoff function and adds the specified jitter percentage. j can be interpreted as "+/- j%". For example, if j were 5 and the backoff returned 20s, the value could be between 19 and 21 seconds. The value can never be less than 0 or greater than 100.

func WithMaxDuration

func WithMaxDuration(timeout time.Duration, next Backoff) Backoff

WithMaxDuration sets a maximum on the total amount of time a backoff should execute. It's best-effort, and should not be used to guarantee an exact amount of time.

func WithMaxRetries

func WithMaxRetries(max uint32, next Backoff) Backoff

WithMaxRetries executes the backoff function up until the maximum attempts.

type BackoffFunc

type BackoffFunc func() (time.Duration, bool)

BackoffFunc is a backoff expressed as a function.

func (BackoffFunc) Next

func (b BackoffFunc) Next() (time.Duration, bool)

Next implements Backoff.

type Retry

type Retry func() Backoff

func Default

func Default() Retry

func New

func New(bs ...Backoff) Retry

func (Retry) Do

func (d Retry) Do(f func(i int) error) (err error)

func (Retry) DoVal

func (d Retry) DoVal(f func(i int) (interface{}, error)) (val interface{}, err error)