Simple library for retry mechanism
slightly inspired by Try::Tiny::Retry
http get with retry:
url := "http://example.com"
var body []byte
err := retry.Do(
func() error {
resp, err := http.Get(url)
if err != nil {
return err
}
defer resp.Body.Close()
body, err = ioutil.ReadAll(resp.Body)
if err != nil {
return err
}
return nil
},
)
fmt.Println(body)
-
giantswarm/retry-go - slightly complicated interface.
-
sethgrid/pester - only http retry for http calls with retries and backoff
-
cenkalti/backoff - Go port of the exponential backoff algorithm from Google's HTTP Client Library for Java. Really complicated interface.
-
rafaeljesus/retry-go - looks good, slightly similar as this package, don't have 'simple'
Retrymethod -
matryer/try - very popular package, nonintuitive interface (for me)
1.0.2 -> 2.0.0
-
argument of
retry.Delayis final delay (no multiplication byretry.Unitsanymore) -
function
retry.Unitsare removed
0.3.0 -> 1.0.0
-
retry.Retryfunction are changed toretry.Dofunction -
retry.RetryCustom(OnRetry) andretry.RetryCustomWithOptsfunctions are now implement via functions produces Options (akaretry.OnRetry)
func BackOffDelay(n uint, config *config) time.DurationBackOffDelay is a DelayType which increases delay between consecutive retries
func Do(retryableFunc RetryableFunc, opts ...Option) errorfunc FixedDelay(_ uint, config *config) time.DurationFixedDelay is a DelayType which keeps delay the same through all iterations
type DelayTypeFunc func(n uint, config *config) time.Durationtype Error []errorError type represents list of errors in retry
func (e Error) Error() stringError method return string representation of Error It is an implementation of error interface
func (e Error) WrappedErrors() []errorWrappedErrors returns the list of errors that this Error is wrapping. It is an
implementation of the errwrap.Wrapper interface in package
errwrap so that retry.Error can be
used with that library.
type OnRetryFunc func(n uint, err error)Function signature of OnRetry function n = count of attempts
type Option func(*config)Option represents an option for retry.
func Attempts(attempts uint) OptionAttempts set count of retry default is 10
func Delay(delay time.Duration) OptionDelay set delay between retry default is 100ms
func DelayType(delayType DelayTypeFunc) OptionDelayType set type of the delay between retries default is BackOff
func OnRetry(onRetry OnRetryFunc) OptionOnRetry function callback are called each retry
log each retry example:
retry.Do(
func() error {
return errors.New("some error")
},
retry.OnRetry(func(n uint, err error) {
log.Printf("#%d: %s\n", n, err)
}),
)
func RetryIf(retryIf RetryIfFunc) OptionRetryIf controls whether a retry should be attempted after an error (assuming there are any retry attempts remaining)
skip retry if special error example:
retry.Do(
func() error {
return errors.New("special error")
},
retry.RetryIf(func(err error) bool {
if err.Error() == "special error" {
return false
}
return true
})
)
type RetryIfFunc func(error) boolFunction signature of retry if function
type RetryableFunc func() errorFunction signature of retryable function
Contributions are very much welcome.
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