57 lines
1.5 KiB
Go
57 lines
1.5 KiB
Go
// Copyright 2012-present Oliver Eilhard. All rights reserved.
|
||
// Use of this source code is governed by a MIT-license.
|
||
// See http://olivere.mit-license.org/license.txt for details.
|
||
|
||
// This file is based on code (c) 2014 Cenk Altı and governed by the MIT license.
|
||
// See https://github.com/cenkalti/backoff for original source.
|
||
|
||
package elastic
|
||
|
||
import "time"
|
||
|
||
// An Operation is executing by Retry() or RetryNotify().
|
||
// The operation will be retried using a backoff policy if it returns an error.
|
||
type Operation func() error
|
||
|
||
// Notify is a notify-on-error function. It receives error returned
|
||
// from an operation.
|
||
//
|
||
// Notice that if the backoff policy stated to stop retrying,
|
||
// the notify function isn't called.
|
||
type Notify func(error)
|
||
|
||
// Retry the function f until it does not return error or BackOff stops.
|
||
// f is guaranteed to be run at least once.
|
||
// It is the caller's responsibility to reset b after Retry returns.
|
||
//
|
||
// Retry sleeps the goroutine for the duration returned by BackOff after a
|
||
// failed operation returns.
|
||
func Retry(o Operation, b Backoff) error { return RetryNotify(o, b, nil) }
|
||
|
||
// RetryNotify calls notify function with the error and wait duration
|
||
// for each failed attempt before sleep.
|
||
func RetryNotify(operation Operation, b Backoff, notify Notify) error {
|
||
var err error
|
||
var wait time.Duration
|
||
var retry bool
|
||
var n int
|
||
|
||
for {
|
||
if err = operation(); err == nil {
|
||
return nil
|
||
}
|
||
|
||
n++
|
||
wait, retry = b.Next(n)
|
||
if !retry {
|
||
return err
|
||
}
|
||
|
||
if notify != nil {
|
||
notify(err)
|
||
}
|
||
|
||
time.Sleep(wait)
|
||
}
|
||
}
|