mirror of
https://github.com/Luzifer/nginx-sso.git
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59 lines
1.2 KiB
Go
59 lines
1.2 KiB
Go
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// +build go1.12
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/*
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* Copyright 2019 gRPC authors.
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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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*/
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package edsbalancer
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import (
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"sync"
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)
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type dropper struct {
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// Drop rate will be numerator/denominator.
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numerator uint32
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denominator uint32
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mu sync.Mutex
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i uint32
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}
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func newDropper(numerator, denominator uint32) *dropper {
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return &dropper{
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numerator: numerator,
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denominator: denominator,
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}
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}
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func (d *dropper) drop() (ret bool) {
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d.mu.Lock()
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defer d.mu.Unlock()
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// TODO: the drop algorithm needs a design.
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// Currently, for drop rate 3/5:
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// 0 1 2 3 4
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// d d d n n
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if d.i < d.numerator {
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ret = true
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}
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d.i++
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if d.i >= d.denominator {
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d.i = 0
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}
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return
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}
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