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
|
// Copyright 2014 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 "base/test/histogram_tester.h"
#include <stddef.h>
#include "base/metrics/histogram.h"
#include "base/metrics/histogram_samples.h"
#include "base/metrics/metrics_hashes.h"
#include "base/metrics/sample_map.h"
#include "base/metrics/statistics_recorder.h"
#include "base/strings/string_util.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
HistogramTester::HistogramTester() {
StatisticsRecorder::Initialize(); // Safe to call multiple times.
// Record any histogram data that exists when the object is created so it can
// be subtracted later.
StatisticsRecorder::Histograms histograms;
StatisticsRecorder::GetSnapshot(std::string(), &histograms);
for (const auto& histogram : histograms) {
histograms_snapshot_[histogram->histogram_name()] =
histogram->SnapshotSamples();
}
}
HistogramTester::~HistogramTester() {
}
void HistogramTester::ExpectUniqueSample(
const std::string& name,
HistogramBase::Sample sample,
HistogramBase::Count expected_count) const {
HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
EXPECT_NE(nullptr, histogram) << "Histogram \"" << name
<< "\" does not exist.";
if (histogram) {
std::unique_ptr<HistogramSamples> samples = histogram->SnapshotSamples();
CheckBucketCount(name, sample, expected_count, *samples);
CheckTotalCount(name, expected_count, *samples);
}
}
void HistogramTester::ExpectBucketCount(
const std::string& name,
HistogramBase::Sample sample,
HistogramBase::Count expected_count) const {
HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
EXPECT_NE(nullptr, histogram) << "Histogram \"" << name
<< "\" does not exist.";
if (histogram) {
std::unique_ptr<HistogramSamples> samples = histogram->SnapshotSamples();
CheckBucketCount(name, sample, expected_count, *samples);
}
}
void HistogramTester::ExpectTotalCount(const std::string& name,
HistogramBase::Count count) const {
HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
if (histogram) {
std::unique_ptr<HistogramSamples> samples = histogram->SnapshotSamples();
CheckTotalCount(name, count, *samples);
} else {
// No histogram means there were zero samples.
EXPECT_EQ(count, 0) << "Histogram \"" << name << "\" does not exist.";
}
}
void HistogramTester::ExpectTimeBucketCount(const std::string& name,
TimeDelta sample,
HistogramBase::Count count) const {
ExpectBucketCount(name, sample.InMilliseconds(), count);
}
std::vector<Bucket> HistogramTester::GetAllSamples(
const std::string& name) const {
std::vector<Bucket> samples;
std::unique_ptr<HistogramSamples> snapshot =
GetHistogramSamplesSinceCreation(name);
if (snapshot) {
for (auto it = snapshot->Iterator(); !it->Done(); it->Next()) {
HistogramBase::Sample sample;
HistogramBase::Count count;
it->Get(&sample, nullptr, &count);
samples.push_back(Bucket(sample, count));
}
}
return samples;
}
HistogramTester::CountsMap HistogramTester::GetTotalCountsForPrefix(
const std::string& prefix) const {
EXPECT_TRUE(prefix.find('.') != std::string::npos)
<< "|prefix| ought to contain at least one period, to avoid matching too"
<< " many histograms.";
// Find candidate matches by using the logic built into GetSnapshot().
StatisticsRecorder::Histograms candidate_matches;
StatisticsRecorder::GetSnapshot(prefix, &candidate_matches);
CountsMap result;
for (HistogramBase* histogram : candidate_matches) {
if (!StartsWith(histogram->histogram_name(), prefix,
CompareCase::SENSITIVE)) {
continue;
}
std::unique_ptr<HistogramSamples> new_samples =
GetHistogramSamplesSinceCreation(histogram->histogram_name());
// Omit unchanged histograms from the result.
if (new_samples->TotalCount()) {
result[histogram->histogram_name()] = new_samples->TotalCount();
}
}
return result;
}
std::unique_ptr<HistogramSamples>
HistogramTester::GetHistogramSamplesSinceCreation(
const std::string& histogram_name) const {
HistogramBase* histogram = StatisticsRecorder::FindHistogram(histogram_name);
// Whether the histogram exists or not may not depend on the current test
// calling this method, but rather on which tests ran before and possibly
// generated a histogram or not (see http://crbug.com/473689). To provide a
// response which is independent of the previously run tests, this method
// creates empty samples in the absence of the histogram, rather than
// returning null.
if (!histogram) {
return std::unique_ptr<HistogramSamples>(
new SampleMap(HashMetricName(histogram_name)));
}
std::unique_ptr<HistogramSamples> named_samples =
histogram->SnapshotSamples();
auto original_samples_it = histograms_snapshot_.find(histogram_name);
if (original_samples_it != histograms_snapshot_.end())
named_samples->Subtract(*original_samples_it->second.get());
return named_samples;
}
void HistogramTester::CheckBucketCount(const std::string& name,
HistogramBase::Sample sample,
HistogramBase::Count expected_count,
const HistogramSamples& samples) const {
int actual_count = samples.GetCount(sample);
auto histogram_data = histograms_snapshot_.find(name);
if (histogram_data != histograms_snapshot_.end())
actual_count -= histogram_data->second->GetCount(sample);
EXPECT_EQ(expected_count, actual_count)
<< "Histogram \"" << name
<< "\" does not have the right number of samples (" << expected_count
<< ") in the expected bucket (" << sample << "). It has (" << actual_count
<< ").";
}
void HistogramTester::CheckTotalCount(const std::string& name,
HistogramBase::Count expected_count,
const HistogramSamples& samples) const {
int actual_count = samples.TotalCount();
auto histogram_data = histograms_snapshot_.find(name);
if (histogram_data != histograms_snapshot_.end())
actual_count -= histogram_data->second->TotalCount();
EXPECT_EQ(expected_count, actual_count)
<< "Histogram \"" << name
<< "\" does not have the right total number of samples ("
<< expected_count << "). It has (" << actual_count << ").";
}
bool Bucket::operator==(const Bucket& other) const {
return min == other.min && count == other.count;
}
void PrintTo(const Bucket& bucket, std::ostream* os) {
*os << "Bucket " << bucket.min << ": " << bucket.count;
}
} // namespace base
|
