106 lines
2.2 KiB
Go
106 lines
2.2 KiB
Go
/*
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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 wrr
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import (
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"errors"
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"math"
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"math/rand"
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"testing"
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"github.com/google/go-cmp/cmp"
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)
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const iterCount = 10000
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func equalApproximate(a, b float64) error {
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opt := cmp.Comparer(func(x, y float64) bool {
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delta := math.Abs(x - y)
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mean := math.Abs(x+y) / 2.0
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return delta/mean < 0.05
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})
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if !cmp.Equal(a, b, opt) {
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return errors.New(cmp.Diff(a, b))
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}
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return nil
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}
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func testWRRNext(t *testing.T, newWRR func() WRR) {
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tests := []struct {
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name string
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weights []int64
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}{
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{
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name: "1-1-1",
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weights: []int64{1, 1, 1},
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},
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{
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name: "1-2-3",
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weights: []int64{1, 2, 3},
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},
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{
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name: "5-3-2",
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weights: []int64{5, 3, 2},
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},
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{
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name: "17-23-37",
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weights: []int64{17, 23, 37},
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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var sumOfWeights int64
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w := newWRR()
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for i, weight := range tt.weights {
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w.Add(i, weight)
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sumOfWeights += weight
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}
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results := make(map[int]int)
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for i := 0; i < iterCount; i++ {
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results[w.Next().(int)]++
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}
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wantRatio := make([]float64, len(tt.weights))
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for i, weight := range tt.weights {
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wantRatio[i] = float64(weight) / float64(sumOfWeights)
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}
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gotRatio := make([]float64, len(tt.weights))
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for i, count := range results {
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gotRatio[i] = float64(count) / iterCount
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}
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for i := range wantRatio {
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if err := equalApproximate(gotRatio[i], wantRatio[i]); err != nil {
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t.Errorf("%v not equal %v", i, err)
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}
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}
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})
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}
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}
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func TestRandomWRRNext(t *testing.T) {
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testWRRNext(t, NewRandom)
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}
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func init() {
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r := rand.New(rand.NewSource(0))
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grpcrandInt63n = r.Int63n
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}
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