1 // Copyright 2014 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 "base/test/histogram_tester.h" 6 7 #include "base/metrics/histogram.h" 8 #include "base/metrics/histogram_samples.h" 9 #include "base/metrics/statistics_recorder.h" 10 #include "base/stl_util.h" 11 #include "testing/gtest/include/gtest/gtest.h" 12 13 namespace base { 14 15 HistogramTester::HistogramTester() { 16 StatisticsRecorder::Initialize(); // Safe to call multiple times. 17 18 // Record any histogram data that exists when the object is created so it can 19 // be subtracted later. 20 StatisticsRecorder::Histograms histograms; 21 StatisticsRecorder::GetSnapshot(std::string(), &histograms); 22 for (size_t i = 0; i < histograms.size(); ++i) { 23 histograms_snapshot_[histograms[i]->histogram_name()] = 24 histograms[i]->SnapshotSamples().release(); 25 } 26 } 27 28 HistogramTester::~HistogramTester() { 29 STLDeleteValues(&histograms_snapshot_); 30 } 31 32 void HistogramTester::ExpectUniqueSample( 33 const std::string& name, 34 base::HistogramBase::Sample sample, 35 base::HistogramBase::Count expected_count) const { 36 base::HistogramBase* histogram = 37 base::StatisticsRecorder::FindHistogram(name); 38 EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram) 39 << "Histogram \"" << name << "\" does not exist."; 40 41 if (histogram) { 42 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples()); 43 CheckBucketCount(name, sample, expected_count, *samples); 44 CheckTotalCount(name, expected_count, *samples); 45 } 46 } 47 48 void HistogramTester::ExpectBucketCount( 49 const std::string& name, 50 base::HistogramBase::Sample sample, 51 base::HistogramBase::Count expected_count) const { 52 base::HistogramBase* histogram = 53 base::StatisticsRecorder::FindHistogram(name); 54 EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram) 55 << "Histogram \"" << name << "\" does not exist."; 56 57 if (histogram) { 58 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples()); 59 CheckBucketCount(name, sample, expected_count, *samples); 60 } 61 } 62 63 void HistogramTester::ExpectTotalCount(const std::string& name, 64 base::HistogramBase::Count count) const { 65 base::HistogramBase* histogram = 66 base::StatisticsRecorder::FindHistogram(name); 67 if (histogram) { 68 scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples()); 69 CheckTotalCount(name, count, *samples); 70 } else { 71 // No histogram means there were zero samples. 72 EXPECT_EQ(count, 0) << "Histogram \"" << name << "\" does not exist."; 73 } 74 } 75 76 scoped_ptr<HistogramSamples> HistogramTester::GetHistogramSamplesSinceCreation( 77 const std::string& histogram_name) { 78 HistogramBase* histogram = StatisticsRecorder::FindHistogram(histogram_name); 79 if (!histogram) 80 return scoped_ptr<HistogramSamples>(); 81 scoped_ptr<HistogramSamples> named_samples(histogram->SnapshotSamples()); 82 HistogramSamples* named_original_samples = 83 histograms_snapshot_[histogram_name]; 84 if (named_original_samples) 85 named_samples->Subtract(*named_original_samples); 86 return named_samples.Pass(); 87 } 88 89 void HistogramTester::CheckBucketCount( 90 const std::string& name, 91 base::HistogramBase::Sample sample, 92 base::HistogramBase::Count expected_count, 93 base::HistogramSamples& samples) const { 94 int actual_count = samples.GetCount(sample); 95 std::map<std::string, HistogramSamples*>::const_iterator histogram_data; 96 histogram_data = histograms_snapshot_.find(name); 97 if (histogram_data != histograms_snapshot_.end()) 98 actual_count -= histogram_data->second->GetCount(sample); 99 100 EXPECT_EQ(expected_count, actual_count) 101 << "Histogram \"" << name 102 << "\" does not have the right number of samples (" << expected_count 103 << ") in the expected bucket (" << sample << "). It has (" << actual_count 104 << ")."; 105 } 106 107 void HistogramTester::CheckTotalCount(const std::string& name, 108 base::HistogramBase::Count expected_count, 109 base::HistogramSamples& samples) const { 110 int actual_count = samples.TotalCount(); 111 std::map<std::string, HistogramSamples*>::const_iterator histogram_data; 112 histogram_data = histograms_snapshot_.find(name); 113 if (histogram_data != histograms_snapshot_.end()) 114 actual_count -= histogram_data->second->TotalCount(); 115 116 EXPECT_EQ(expected_count, actual_count) 117 << "Histogram \"" << name 118 << "\" does not have the right total number of samples (" 119 << expected_count << "). It has (" << actual_count << ")."; 120 } 121 122 } // namespace base 123