mirror of
https://github.com/octoleo/restic.git
synced 2024-11-18 11:05:18 +00:00
39 lines
1.2 KiB
Go
39 lines
1.2 KiB
Go
// Copyright 2018, OpenCensus Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package ocagent
|
|
|
|
import (
|
|
"math/rand"
|
|
"time"
|
|
)
|
|
|
|
var randSrc = rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
|
|
// retries function fn upto n times, if fn returns an error lest it returns nil early.
|
|
// It applies exponential backoff in units of (1<<n) + jitter microsends.
|
|
func nTriesWithExponentialBackoff(nTries int64, timeBaseUnit time.Duration, fn func() error) (err error) {
|
|
for i := int64(0); i < nTries; i++ {
|
|
err = fn()
|
|
if err == nil {
|
|
return nil
|
|
}
|
|
// Backoff for a time period with a pseudo-random jitter
|
|
jitter := time.Duration(randSrc.Float64()*100) * time.Microsecond
|
|
ts := jitter + ((1 << uint64(i)) * timeBaseUnit)
|
|
<-time.After(ts)
|
|
}
|
|
return err
|
|
}
|