1// Copyright 2020 The go-ethereum Authors
2// This file is part of the go-ethereum library.
3//
4// The go-ethereum library is free software: you can redistribute it and/or modify
5// it under the terms of the GNU Lesser General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// The go-ethereum library is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU Lesser General Public License for more details.
13//
14// You should have received a copy of the GNU Lesser General Public License
15// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
16
17package client
18
19import (
20	"math"
21	"math/rand"
22	"testing"
23	"time"
24
25	"github.com/ethereum/go-ethereum/les/utils"
26)
27
28func TestTransition(t *testing.T) {
29	var epsilon = 0.01
30	var cases = []time.Duration{
31		time.Millisecond, minResponseTime,
32		time.Second, time.Second * 5, maxResponseTime,
33	}
34	for _, c := range cases {
35		got := StatScaleToTime(TimeToStatScale(c))
36		if float64(got)*(1+epsilon) < float64(c) || float64(got)*(1-epsilon) > float64(c) {
37			t.Fatalf("Failed to transition back")
38		}
39	}
40	// If the time is too large(exceeds the max response time.
41	got := StatScaleToTime(TimeToStatScale(2 * maxResponseTime))
42	if float64(got)*(1+epsilon) < float64(maxResponseTime) || float64(got)*(1-epsilon) > float64(maxResponseTime) {
43		t.Fatalf("Failed to transition back")
44	}
45}
46
47var maxResponseWeights = TimeoutWeights(maxResponseTime)
48
49func TestValue(t *testing.T) {
50	noexp := utils.ExpirationFactor{Factor: 1}
51	for i := 0; i < 1000; i++ {
52		max := minResponseTime + time.Duration(rand.Int63n(int64(maxResponseTime-minResponseTime)))
53		min := minResponseTime + time.Duration(rand.Int63n(int64(max-minResponseTime)))
54		timeout := max/2 + time.Duration(rand.Int63n(int64(maxResponseTime-max/2)))
55		s := makeRangeStats(min, max, 1000, noexp)
56		value := s.Value(TimeoutWeights(timeout), noexp)
57		// calculate the average weight (the average of the given range of the half cosine
58		// weight function).
59		minx := math.Pi / 2 * float64(min) / float64(timeout)
60		maxx := math.Pi / 2 * float64(max) / float64(timeout)
61		avgWeight := (math.Sin(maxx) - math.Sin(minx)) / (maxx - minx)
62		expv := 1000 * avgWeight
63		if expv < 0 {
64			expv = 0
65		}
66		if value < expv-10 || value > expv+10 {
67			t.Errorf("Value failed (expected %v, got %v)", expv, value)
68		}
69	}
70}
71
72func TestAddSubExpire(t *testing.T) {
73	var (
74		sum1, sum2                 ResponseTimeStats
75		sum1ValueExp, sum2ValueExp float64
76		logOffset                  utils.Fixed64
77	)
78	for i := 0; i < 1000; i++ {
79		exp := utils.ExpFactor(logOffset)
80		max := minResponseTime + time.Duration(rand.Int63n(int64(maxResponseTime-minResponseTime)))
81		min := minResponseTime + time.Duration(rand.Int63n(int64(max-minResponseTime)))
82		s := makeRangeStats(min, max, 1000, exp)
83		value := s.Value(maxResponseWeights, exp)
84		sum1.AddStats(&s)
85		sum1ValueExp += value
86		if rand.Intn(2) == 1 {
87			sum2.AddStats(&s)
88			sum2ValueExp += value
89		}
90		logOffset += utils.Float64ToFixed64(0.001 / math.Log(2))
91		sum1ValueExp -= sum1ValueExp * 0.001
92		sum2ValueExp -= sum2ValueExp * 0.001
93	}
94	exp := utils.ExpFactor(logOffset)
95	sum1Value := sum1.Value(maxResponseWeights, exp)
96	if sum1Value < sum1ValueExp*0.99 || sum1Value > sum1ValueExp*1.01 {
97		t.Errorf("sum1Value failed (expected %v, got %v)", sum1ValueExp, sum1Value)
98	}
99	sum2Value := sum2.Value(maxResponseWeights, exp)
100	if sum2Value < sum2ValueExp*0.99 || sum2Value > sum2ValueExp*1.01 {
101		t.Errorf("sum2Value failed (expected %v, got %v)", sum2ValueExp, sum2Value)
102	}
103	diff := sum1
104	diff.SubStats(&sum2)
105	diffValue := diff.Value(maxResponseWeights, exp)
106	diffValueExp := sum1ValueExp - sum2ValueExp
107	if diffValue < diffValueExp*0.99 || diffValue > diffValueExp*1.01 {
108		t.Errorf("diffValue failed (expected %v, got %v)", diffValueExp, diffValue)
109	}
110}
111
112func TestTimeout(t *testing.T) {
113	testTimeoutRange(t, 0, time.Second)
114	testTimeoutRange(t, time.Second, time.Second*2)
115	testTimeoutRange(t, time.Second, maxResponseTime)
116}
117
118func testTimeoutRange(t *testing.T, min, max time.Duration) {
119	s := makeRangeStats(min, max, 1000, utils.ExpirationFactor{Factor: 1})
120	for i := 2; i < 9; i++ {
121		to := s.Timeout(float64(i) / 10)
122		exp := max - (max-min)*time.Duration(i)/10
123		tol := (max - min) / 50
124		if to < exp-tol || to > exp+tol {
125			t.Errorf("Timeout failed (expected %v, got %v)", exp, to)
126		}
127	}
128}
129
130func makeRangeStats(min, max time.Duration, amount float64, exp utils.ExpirationFactor) ResponseTimeStats {
131	var s ResponseTimeStats
132	amount /= 1000
133	for i := 0; i < 1000; i++ {
134		s.Add(min+(max-min)*time.Duration(i)/999, amount, exp)
135	}
136	return s
137}
138