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