mirror of
https://github.com/octoleo/restic.git
synced 2024-11-30 16:53:59 +00:00
85 lines
2.4 KiB
Go
85 lines
2.4 KiB
Go
/*
|
|
Copyright 2015 Google Inc. All Rights Reserved.
|
|
|
|
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.
|
|
*/
|
|
|
|
// This is ia snapshot from github.com/googleapis/gax-go with minor modifications.
|
|
package gax
|
|
|
|
import (
|
|
"math/rand"
|
|
"time"
|
|
|
|
"golang.org/x/net/context"
|
|
"google.golang.org/grpc"
|
|
"google.golang.org/grpc/codes"
|
|
"log"
|
|
"os"
|
|
)
|
|
|
|
var logger *log.Logger = log.New(os.Stderr, "", log.LstdFlags)
|
|
|
|
// A user defined call stub.
|
|
type APICall func(context.Context) error
|
|
|
|
// scaleDuration returns the product of a and mult.
|
|
func scaleDuration(a time.Duration, mult float64) time.Duration {
|
|
ns := float64(a) * mult
|
|
return time.Duration(ns)
|
|
}
|
|
|
|
// invokeWithRetry calls stub using an exponential backoff retry mechanism
|
|
// based on the values provided in callSettings.
|
|
func invokeWithRetry(ctx context.Context, stub APICall, callSettings CallSettings) error {
|
|
retrySettings := callSettings.RetrySettings
|
|
backoffSettings := callSettings.RetrySettings.BackoffSettings
|
|
delay := backoffSettings.DelayTimeoutSettings.Initial
|
|
for {
|
|
// If the deadline is exceeded...
|
|
if ctx.Err() != nil {
|
|
return ctx.Err()
|
|
}
|
|
err := stub(ctx)
|
|
code := grpc.Code(err)
|
|
if code == codes.OK {
|
|
return nil
|
|
}
|
|
|
|
if !retrySettings.RetryCodes[code] {
|
|
return err
|
|
}
|
|
|
|
// Sleep a random amount up to the current delay
|
|
d := time.Duration(rand.Int63n(int64(delay)))
|
|
delayCtx, _ := context.WithTimeout(ctx, delay)
|
|
logger.Printf("Retryable error: %v, retrying in %v", err, d)
|
|
<-delayCtx.Done()
|
|
|
|
delay = scaleDuration(delay, backoffSettings.DelayTimeoutSettings.Multiplier)
|
|
if delay > backoffSettings.DelayTimeoutSettings.Max {
|
|
delay = backoffSettings.DelayTimeoutSettings.Max
|
|
}
|
|
}
|
|
}
|
|
|
|
// Invoke calls stub with a child of context modified by the specified options.
|
|
func Invoke(ctx context.Context, stub APICall, opts ...CallOption) error {
|
|
settings := &CallSettings{}
|
|
callOptions(opts).Resolve(settings)
|
|
if len(settings.RetrySettings.RetryCodes) > 0 {
|
|
return invokeWithRetry(ctx, stub, *settings)
|
|
}
|
|
return stub(ctx)
|
|
}
|