63 lines
1.5 KiB
Go
63 lines
1.5 KiB
Go
/*
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* Copyright 1999-2020 Alibaba Group Holding Ltd.
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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 naming_client
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import (
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"math/rand"
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"sort"
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"github.com/nacos-group/nacos-sdk-go/v2/model"
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)
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type Chooser struct {
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data []model.Instance
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totals []int
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max int
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}
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type instance []model.Instance
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func (a instance) Len() int {
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return len(a)
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}
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func (a instance) Swap(i, j int) {
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a[i], a[j] = a[j], a[i]
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}
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func (a instance) Less(i, j int) bool {
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return a[i].Weight < a[j].Weight
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}
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// NewChooser initializes a new Chooser for picking from the provided Choices.
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func newChooser(instances []model.Instance) Chooser {
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sort.Sort(instance(instances))
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totals := make([]int, len(instances))
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runningTotal := 0
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for i, c := range instances {
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runningTotal += int(c.Weight)
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totals[i] = runningTotal
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}
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return Chooser{data: instances, totals: totals, max: runningTotal}
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}
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func (chs Chooser) pick() model.Instance {
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r := rand.Intn(chs.max) + 1
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i := sort.SearchInts(chs.totals, r)
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return chs.data[i]
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}
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