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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
|
// 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.
// Test of FieldTrial class
#include "base/metrics/field_trial.h"
#include "base/stringprintf.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
class FieldTrialTest : public testing::Test {
public:
FieldTrialTest() : trial_list_() {
Time now = Time::NowFromSystemTime();
TimeDelta oneYear = TimeDelta::FromDays(365);
Time::Exploded exploded;
Time next_year_time = now + oneYear;
next_year_time.LocalExplode(&exploded);
next_year_ = exploded.year;
Time last_year_time = now - oneYear;
last_year_time.LocalExplode(&exploded);
last_year_ = exploded.year;
}
protected:
int next_year_;
int last_year_;
private:
FieldTrialList trial_list_;
};
// Test registration, and also check that destructors are called for trials
// (and that Purify doesn't catch us leaking).
TEST_F(FieldTrialTest, Registration) {
const char* name1 = "name 1 test";
const char* name2 = "name 2 test";
EXPECT_FALSE(FieldTrialList::Find(name1));
EXPECT_FALSE(FieldTrialList::Find(name2));
FieldTrial* trial1 =
new FieldTrial(name1, 10, "default name 1 test", next_year_, 12, 31);
EXPECT_EQ(FieldTrial::kNotFinalized, trial1->group_);
EXPECT_EQ(name1, trial1->name());
EXPECT_EQ("", trial1->group_name_internal());
trial1->AppendGroup("", 7);
EXPECT_EQ(trial1, FieldTrialList::Find(name1));
EXPECT_FALSE(FieldTrialList::Find(name2));
FieldTrial* trial2 =
new FieldTrial(name2, 10, "default name 2 test", next_year_, 12, 31);
EXPECT_EQ(FieldTrial::kNotFinalized, trial2->group_);
EXPECT_EQ(name2, trial2->name());
EXPECT_EQ("", trial2->group_name_internal());
trial2->AppendGroup("a first group", 7);
EXPECT_EQ(trial1, FieldTrialList::Find(name1));
EXPECT_EQ(trial2, FieldTrialList::Find(name2));
// Note: FieldTrialList should delete the objects at shutdown.
}
TEST_F(FieldTrialTest, AbsoluteProbabilities) {
char always_true[] = " always true";
char default_always_true[] = " default always true";
char always_false[] = " always false";
char default_always_false[] = " default always false";
for (int i = 1; i < 250; ++i) {
// Try lots of names, by changing the first character of the name.
always_true[0] = i;
default_always_true[0] = i;
always_false[0] = i;
default_always_false[0] = i;
FieldTrial* trial_true =
new FieldTrial(
always_true, 10, default_always_true, next_year_, 12, 31);
const std::string winner = "TheWinner";
int winner_group = trial_true->AppendGroup(winner, 10);
EXPECT_EQ(winner_group, trial_true->group());
EXPECT_EQ(winner, trial_true->group_name());
FieldTrial* trial_false =
new FieldTrial(
always_false, 10, default_always_false, next_year_, 12, 31);
int loser_group = trial_false->AppendGroup("ALoser", 0);
EXPECT_NE(loser_group, trial_false->group());
}
}
TEST_F(FieldTrialTest, RemainingProbability) {
// First create a test that hasn't had a winner yet.
const std::string winner = "Winner";
const std::string loser = "Loser";
scoped_refptr<FieldTrial> trial;
int counter = 0;
do {
std::string name = StringPrintf("trial%d", ++counter);
trial = new FieldTrial(name, 10, winner, next_year_, 12, 31);
trial->AppendGroup(loser, 5); // 50% chance of not being chosen.
// If a group is not assigned, group_ will be kNotFinalized.
} while (trial->group_ != FieldTrial::kNotFinalized);
// And that 'default' group (winner) should always win.
EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());
// And that winner should ALWAYS win.
EXPECT_EQ(winner, trial->group_name());
}
TEST_F(FieldTrialTest, FiftyFiftyProbability) {
// Check that even with small divisors, we have the proper probabilities, and
// all outcomes are possible. Since this is a 50-50 test, it should get both
// outcomes in a few tries, but we'll try no more than 100 times (and be flaky
// with probability around 1 in 2^99).
bool first_winner = false;
bool second_winner = false;
int counter = 0;
do {
std::string name = base::StringPrintf("FiftyFifty%d", ++counter);
std::string default_group_name = base::StringPrintf("Default FiftyFifty%d",
++counter);
scoped_refptr<FieldTrial> trial(
new FieldTrial(name, 2, default_group_name, next_year_, 12, 31));
trial->AppendGroup("first", 1); // 50% chance of being chosen.
// If group_ is kNotFinalized, then a group assignement hasn't been done.
if (trial->group_ != FieldTrial::kNotFinalized) {
first_winner = true;
continue;
}
trial->AppendGroup("second", 1); // Always chosen at this point.
EXPECT_NE(FieldTrial::kNotFinalized, trial->group());
second_winner = true;
} while ((!second_winner || !first_winner) && counter < 100);
EXPECT_TRUE(second_winner);
EXPECT_TRUE(first_winner);
}
TEST_F(FieldTrialTest, MiddleProbabilities) {
char name[] = " same name";
char default_group_name[] = " default same name";
bool false_event_seen = false;
bool true_event_seen = false;
for (int i = 1; i < 250; ++i) {
name[0] = i;
default_group_name[0] = i;
FieldTrial* trial =
new FieldTrial(name, 10, default_group_name, next_year_, 12, 31);
int might_win = trial->AppendGroup("MightWin", 5);
if (trial->group() == might_win) {
true_event_seen = true;
} else {
false_event_seen = true;
}
if (false_event_seen && true_event_seen)
return; // Successful test!!!
}
// Very surprising to get here. Probability should be around 1 in 2 ** 250.
// One of the following will fail.
EXPECT_TRUE(false_event_seen);
EXPECT_TRUE(true_event_seen);
}
TEST_F(FieldTrialTest, OneWinner) {
char name[] = "Some name";
char default_group_name[] = "Default some name";
int group_count(10);
FieldTrial* trial =
new FieldTrial(
name, group_count, default_group_name, next_year_, 12, 31);
int winner_index(-2);
std::string winner_name;
for (int i = 1; i <= group_count; ++i) {
int might_win = trial->AppendGroup("", 1);
// Because we keep appending groups, we want to see if the last group that
// was added has been assigned or not.
if (trial->group_ == might_win) {
EXPECT_EQ(-2, winner_index);
winner_index = might_win;
StringAppendF(&winner_name, "%d", might_win);
EXPECT_EQ(winner_name, trial->group_name());
}
}
EXPECT_GE(winner_index, 0);
EXPECT_EQ(trial->group(), winner_index);
EXPECT_EQ(trial->group_name(), winner_name);
}
TEST_F(FieldTrialTest, DisableProbability) {
const std::string default_group_name = "Default group";
const std::string loser = "Loser";
const std::string name = "Trial";
// Create a field trail that has expired.
scoped_refptr<FieldTrial> trial;
trial = new FieldTrial(
name, 1000000000, default_group_name, last_year_, 1, 1);
trial->AppendGroup(loser, 999999999); // 99.9999999% chance of being chosen.
// Because trial has expired, we should always be in the default group.
EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());
// And that default_group_name should ALWAYS win.
EXPECT_EQ(default_group_name, trial->group_name());
}
TEST_F(FieldTrialTest, Save) {
std::string save_string;
FieldTrial* trial =
new FieldTrial(
"Some name", 10, "Default some name", next_year_, 12, 31);
// There is no winner yet, so no textual group name is associated with trial.
EXPECT_EQ("", trial->group_name_internal());
FieldTrialList::StatesToString(&save_string);
EXPECT_EQ("Some name/Default some name/", save_string);
save_string.clear();
// Create a winning group.
trial->AppendGroup("Winner", 10);
FieldTrialList::StatesToString(&save_string);
EXPECT_EQ("Some name/Winner/", save_string);
save_string.clear();
// Create a second trial and winning group.
FieldTrial* trial2 =
new FieldTrial("xxx", 10, "Default xxx", next_year_, 12, 31);
trial2->AppendGroup("yyyy", 10);
FieldTrialList::StatesToString(&save_string);
// We assume names are alphabetized... though this is not critical.
EXPECT_EQ("Some name/Winner/xxx/yyyy/", save_string);
}
TEST_F(FieldTrialTest, Restore) {
EXPECT_TRUE(FieldTrialList::Find("Some_name") == NULL);
EXPECT_TRUE(FieldTrialList::Find("xxx") == NULL);
FieldTrialList::CreateTrialsInChildProcess("Some_name/Winner/xxx/yyyy/");
FieldTrial* trial = FieldTrialList::Find("Some_name");
ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
EXPECT_EQ("Winner", trial->group_name());
EXPECT_EQ("Some_name", trial->name());
trial = FieldTrialList::Find("xxx");
ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
EXPECT_EQ("yyyy", trial->group_name());
EXPECT_EQ("xxx", trial->name());
}
TEST_F(FieldTrialTest, BogusRestore) {
EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingSlash"));
EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingGroupName/"));
EXPECT_FALSE(
FieldTrialList::CreateTrialsInChildProcess("MissingFinalSlash/gname"));
EXPECT_FALSE(
FieldTrialList::CreateTrialsInChildProcess("/noname, only group/"));
}
TEST_F(FieldTrialTest, DuplicateRestore) {
FieldTrial* trial =
new FieldTrial(
"Some name", 10, "Default some name", next_year_, 12, 31);
trial->AppendGroup("Winner", 10);
std::string save_string;
FieldTrialList::StatesToString(&save_string);
EXPECT_EQ("Some name/Winner/", save_string);
// It is OK if we redundantly specify a winner.
EXPECT_TRUE(FieldTrialList::CreateTrialsInChildProcess(save_string));
// But it is an error to try to change to a different winner.
EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("Some name/Loser/"));
}
TEST_F(FieldTrialTest, CreateFieldTrial) {
EXPECT_TRUE(FieldTrialList::Find("Some_name") == NULL);
FieldTrialList::CreateFieldTrial("Some_name", "Winner");
FieldTrial* trial = FieldTrialList::Find("Some_name");
ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
EXPECT_EQ("Winner", trial->group_name());
EXPECT_EQ("Some_name", trial->name());
}
TEST_F(FieldTrialTest, DuplicateFieldTrial) {
FieldTrial* trial =
new FieldTrial(
"Some_name", 10, "Default some name", next_year_, 12, 31);
trial->AppendGroup("Winner", 10);
// It is OK if we redundantly specify a winner.
FieldTrial* trial1 = FieldTrialList::CreateFieldTrial("Some_name", "Winner");
EXPECT_TRUE(trial1 != NULL);
// But it is an error to try to change to a different winner.
FieldTrial* trial2 = FieldTrialList::CreateFieldTrial("Some_name", "Loser");
EXPECT_TRUE(trial2 == NULL);
}
TEST_F(FieldTrialTest, MakeName) {
FieldTrial* trial =
new FieldTrial("Field Trial", 10, "Winner", next_year_, 12, 31);
trial->group();
EXPECT_EQ("Histogram_Winner",
FieldTrial::MakeName("Histogram", "Field Trial"));
}
} // namespace base
|