mirror of https://github.com/k3s-io/k3s
73 lines
1.7 KiB
Go
73 lines
1.7 KiB
Go
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// Copyright 2017 Google Inc. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package jsonclient
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import (
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"sync"
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"time"
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)
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type backoff struct {
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mu sync.RWMutex
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multiplier uint
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notBefore time.Time
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}
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const (
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// maximum backoff is 2^(maxMultiplier-1) = 128 seconds
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maxMultiplier = 8
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)
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func (b *backoff) set(override *time.Duration) time.Duration {
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b.mu.Lock()
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defer b.mu.Unlock()
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if b.notBefore.After(time.Now()) {
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if override != nil {
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// If existing backoff is set but override would be longer than
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// it then set it to that.
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notBefore := time.Now().Add(*override)
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if notBefore.After(b.notBefore) {
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b.notBefore = notBefore
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}
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}
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return time.Until(b.notBefore)
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}
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var wait time.Duration
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if override != nil {
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wait = *override
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} else {
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if b.multiplier < maxMultiplier {
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b.multiplier++
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}
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wait = time.Second * time.Duration(1<<(b.multiplier-1))
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}
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b.notBefore = time.Now().Add(wait)
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return wait
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}
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func (b *backoff) decreaseMultiplier() {
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b.mu.Lock()
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defer b.mu.Unlock()
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if b.multiplier > 0 {
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b.multiplier--
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}
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}
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func (b *backoff) until() time.Time {
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b.mu.RLock()
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defer b.mu.RUnlock()
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return b.notBefore
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}
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