1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/base/backoff_entry.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace {
using base::TimeDelta;
using base::TimeTicks;
using net::BackoffEntry;
BackoffEntry::Policy base_policy = { 0, 1000, 2.0, 0.0, 20000, 2000 };
class TestBackoffEntry : public BackoffEntry {
public:
explicit TestBackoffEntry(const Policy* const policy)
: BackoffEntry(policy),
now_(TimeTicks()) {
// Work around initialization in constructor not picking up
// fake time.
SetCustomReleaseTime(TimeTicks());
}
virtual ~TestBackoffEntry() {}
virtual TimeTicks ImplGetTimeNow() const OVERRIDE {
return now_;
}
void set_now(const TimeTicks& now) {
now_ = now;
}
private:
TimeTicks now_;
DISALLOW_COPY_AND_ASSIGN(TestBackoffEntry);
};
TEST(BackoffEntryTest, BaseTest) {
TestBackoffEntry entry(&base_policy);
EXPECT_FALSE(entry.ShouldRejectRequest());
entry.InformOfRequest(false);
EXPECT_TRUE(entry.ShouldRejectRequest());
}
TEST(BackoffEntryTest, CanDiscardNeverExpires) {
BackoffEntry::Policy never_expires_policy = base_policy;
never_expires_policy.entry_lifetime_ms = -1;
TestBackoffEntry never_expires(&never_expires_policy);
EXPECT_FALSE(never_expires.CanDiscard());
never_expires.set_now(TimeTicks() + TimeDelta::FromDays(100));
EXPECT_FALSE(never_expires.CanDiscard());
}
TEST(BackoffEntryTest, CanDiscard) {
TestBackoffEntry entry(&base_policy);
// Because lifetime is non-zero, we shouldn't be able to discard yet.
EXPECT_FALSE(entry.CanDiscard());
// Test the "being used" case.
entry.InformOfRequest(false);
EXPECT_FALSE(entry.CanDiscard());
// Test the case where there are errors but we can time out.
entry.set_now(
entry.GetReleaseTime() + TimeDelta::FromMilliseconds(1));
EXPECT_FALSE(entry.CanDiscard());
entry.set_now(entry.GetReleaseTime() + TimeDelta::FromMilliseconds(
base_policy.maximum_backoff_ms + 1));
EXPECT_TRUE(entry.CanDiscard());
// Test the final case (no errors, dependent only on specified lifetime).
entry.set_now(entry.GetReleaseTime() + TimeDelta::FromMilliseconds(
base_policy.entry_lifetime_ms - 1));
entry.InformOfRequest(true);
EXPECT_FALSE(entry.CanDiscard());
entry.set_now(entry.GetReleaseTime() + TimeDelta::FromMilliseconds(
base_policy.entry_lifetime_ms));
EXPECT_TRUE(entry.CanDiscard());
}
TEST(BackoffEntryTest, CanDiscardNotStored) {
BackoffEntry::Policy no_store_policy = base_policy;
no_store_policy.entry_lifetime_ms = 0;
TestBackoffEntry not_stored(&no_store_policy);
EXPECT_TRUE(not_stored.CanDiscard());
}
TEST(BackoffEntryTest, ShouldIgnoreFirstTwo) {
BackoffEntry::Policy lenient_policy = base_policy;
lenient_policy.num_errors_to_ignore = 2;
BackoffEntry entry(&lenient_policy);
entry.InformOfRequest(false);
EXPECT_FALSE(entry.ShouldRejectRequest());
entry.InformOfRequest(false);
EXPECT_FALSE(entry.ShouldRejectRequest());
entry.InformOfRequest(false);
EXPECT_TRUE(entry.ShouldRejectRequest());
}
TEST(BackoffEntryTest, ReleaseTimeCalculation) {
TestBackoffEntry entry(&base_policy);
// With zero errors, should return "now".
TimeTicks result = entry.GetReleaseTime();
EXPECT_EQ(entry.ImplGetTimeNow(), result);
// 1 error.
entry.InformOfRequest(false);
result = entry.GetReleaseTime();
EXPECT_EQ(entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(1000), result);
// 2 errors.
entry.InformOfRequest(false);
result = entry.GetReleaseTime();
EXPECT_EQ(entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(2000), result);
// 3 errors.
entry.InformOfRequest(false);
result = entry.GetReleaseTime();
EXPECT_EQ(entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(4000), result);
// 6 errors (to check it doesn't pass maximum).
entry.InformOfRequest(false);
entry.InformOfRequest(false);
entry.InformOfRequest(false);
result = entry.GetReleaseTime();
EXPECT_EQ(
entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(20000), result);
}
TEST(BackoffEntryTest, ReleaseTimeCalculationWithJitter) {
for (int i = 0; i < 10; ++i) {
BackoffEntry::Policy jittery_policy = base_policy;
jittery_policy.jitter_factor = 0.2;
TestBackoffEntry entry(&jittery_policy);
entry.InformOfRequest(false);
entry.InformOfRequest(false);
entry.InformOfRequest(false);
TimeTicks result = entry.GetReleaseTime();
EXPECT_LE(
entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(3200), result);
EXPECT_GE(
entry.ImplGetTimeNow() + TimeDelta::FromMilliseconds(4000), result);
}
}
TEST(BackoffEntryTest, FailureThenSuccess) {
TestBackoffEntry entry(&base_policy);
// Failure count 1, establishes horizon.
entry.InformOfRequest(false);
TimeTicks release_time = entry.GetReleaseTime();
EXPECT_EQ(TimeTicks() + TimeDelta::FromMilliseconds(1000), release_time);
// Success, failure count 0, should not advance past
// the horizon that was already set.
entry.set_now(release_time - TimeDelta::FromMilliseconds(200));
entry.InformOfRequest(true);
EXPECT_EQ(release_time, entry.GetReleaseTime());
// Failure, failure count 1.
entry.InformOfRequest(false);
EXPECT_EQ(release_time + TimeDelta::FromMilliseconds(800),
entry.GetReleaseTime());
}
TEST(BackoffEntryTest, RetainCustomHorizon) {
TestBackoffEntry custom(&base_policy);
TimeTicks custom_horizon = TimeTicks() + TimeDelta::FromDays(3);
custom.SetCustomReleaseTime(custom_horizon);
custom.InformOfRequest(false);
custom.InformOfRequest(true);
custom.set_now(TimeTicks() + TimeDelta::FromDays(2));
custom.InformOfRequest(false);
custom.InformOfRequest(true);
EXPECT_EQ(custom_horizon, custom.GetReleaseTime());
// Now check that once we are at or past the custom horizon,
// we get normal behavior.
custom.set_now(TimeTicks() + TimeDelta::FromDays(3));
custom.InformOfRequest(false);
EXPECT_EQ(
TimeTicks() + TimeDelta::FromDays(3) + TimeDelta::FromMilliseconds(1000),
custom.GetReleaseTime());
}
TEST(BackoffEntryTest, RetainCustomHorizonWhenInitialErrorsIgnored) {
// Regression test for a bug discovered during code review.
BackoffEntry::Policy lenient_policy = base_policy;
lenient_policy.num_errors_to_ignore = 1;
TestBackoffEntry custom(&lenient_policy);
TimeTicks custom_horizon = TimeTicks() + TimeDelta::FromDays(3);
custom.SetCustomReleaseTime(custom_horizon);
custom.InformOfRequest(false); // This must not reset the horizon.
EXPECT_EQ(custom_horizon, custom.GetReleaseTime());
}
} // namespace
|
