1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "chrome/test/base/uma_histogram_helper.h"
6
7 #include "base/bind.h"
8 #include "base/metrics/statistics_recorder.h"
9 #include "base/test/test_timeouts.h"
10 #include "chrome/test/base/ui_test_utils.h"
11 #include "content/public/browser/histogram_fetcher.h"
12
UMAHistogramHelper()13 UMAHistogramHelper::UMAHistogramHelper() {
14 base::StatisticsRecorder::Initialize();
15 }
16
~UMAHistogramHelper()17 UMAHistogramHelper::~UMAHistogramHelper() {
18 }
19
PrepareSnapshot(const char * const histogram_names[],size_t num_histograms)20 void UMAHistogramHelper::PrepareSnapshot(const char* const histogram_names[],
21 size_t num_histograms) {
22 for (size_t i = 0; i < num_histograms; ++i) {
23 std::string histogram_name = histogram_names[i];
24
25 base::HistogramBase* histogram =
26 base::StatisticsRecorder::FindHistogram(histogram_name);
27 // If there is no histogram present, then don't record a snapshot. The logic
28 // in the Expect* methods will act to treat no histogram equivalent to
29 // samples with zeros.
30 if (histogram) {
31 histogram_snapshots[histogram_name] =
32 make_linked_ptr(histogram->SnapshotSamples().release());
33 }
34 }
35 }
36
Fetch()37 void UMAHistogramHelper::Fetch() {
38 base::Closure callback = base::Bind(&UMAHistogramHelper::FetchCallback,
39 base::Unretained(this));
40
41 content::FetchHistogramsAsynchronously(
42 base::MessageLoop::current(),
43 callback,
44 // If this call times out, it means that a child process is not
45 // responding, which is something we should not ignore. The timeout is
46 // set to be longer than the normal browser test timeout so that it will
47 // be prempted by the normal timeout.
48 TestTimeouts::action_max_timeout() * 2);
49 content::RunMessageLoop();
50 }
51
ExpectUniqueSample(const std::string & name,base::HistogramBase::Sample sample,base::HistogramBase::Count expected_count)52 void UMAHistogramHelper::ExpectUniqueSample(
53 const std::string& name,
54 base::HistogramBase::Sample sample,
55 base::HistogramBase::Count expected_count) {
56 base::HistogramBase* histogram =
57 base::StatisticsRecorder::FindHistogram(name);
58 EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
59 << "Histogram \"" << name << "\" does not exist.";
60
61 if (histogram) {
62 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples());
63 CheckBucketCount(name, sample, expected_count, *samples);
64 CheckTotalCount(name, expected_count, *samples);
65 }
66 }
67
ExpectBucketCount(const std::string & name,base::HistogramBase::Sample sample,base::HistogramBase::Count expected_count)68 void UMAHistogramHelper::ExpectBucketCount(
69 const std::string& name,
70 base::HistogramBase::Sample sample,
71 base::HistogramBase::Count expected_count) {
72 base::HistogramBase* histogram =
73 base::StatisticsRecorder::FindHistogram(name);
74 EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
75 << "Histogram \"" << name << "\" does not exist.";
76
77 if (histogram) {
78 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples());
79 CheckBucketCount(name, sample, expected_count, *samples);
80 }
81 }
82
ExpectTotalCount(const std::string & name,base::HistogramBase::Count count)83 void UMAHistogramHelper::ExpectTotalCount(
84 const std::string& name,
85 base::HistogramBase::Count count) {
86 base::HistogramBase* histogram =
87 base::StatisticsRecorder::FindHistogram(name);
88 if (histogram) {
89 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples());
90 CheckTotalCount(name, count, *samples);
91 } else {
92 // No histogram means there were zero samples.
93 EXPECT_EQ(count, 0) << "Histogram \"" << name << "\" does not exist.";
94 }
95 }
96
FetchCallback()97 void UMAHistogramHelper::FetchCallback() {
98 base::MessageLoopForUI::current()->Quit();
99 }
100
CheckBucketCount(const std::string & name,base::HistogramBase::Sample sample,base::HistogramBase::Count expected_count,base::HistogramSamples & samples)101 void UMAHistogramHelper::CheckBucketCount(
102 const std::string& name,
103 base::HistogramBase::Sample sample,
104 base::HistogramBase::Count expected_count,
105 base::HistogramSamples& samples) {
106 int actual_count = samples.GetCount(sample);
107 if (histogram_snapshots.count(name))
108 actual_count -= histogram_snapshots[name]->GetCount(sample);
109 EXPECT_EQ(expected_count, actual_count)
110 << "Histogram \"" << name
111 << "\" does not have the right number of samples (" << expected_count
112 << ") in the expected bucket (" << sample << "). It has (" << actual_count
113 << ").";
114 }
115
CheckTotalCount(const std::string & name,base::HistogramBase::Count expected_count,base::HistogramSamples & samples)116 void UMAHistogramHelper::CheckTotalCount(
117 const std::string& name,
118 base::HistogramBase::Count expected_count,
119 base::HistogramSamples& samples) {
120 int actual_count = samples.TotalCount();
121 if (histogram_snapshots.count(name))
122 actual_count -= histogram_snapshots[name]->TotalCount();
123 EXPECT_EQ(expected_count, actual_count)
124 << "Histogram \"" << name
125 << "\" does not have the right total number of samples ("
126 << expected_count << "). It has (" << actual_count << ").";
127 }
128