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 "net/disk_cache/stats_histogram.h" 6 7 #include "base/debug/leak_annotations.h" 8 #include "base/logging.h" 9 #include "base/metrics/bucket_ranges.h" 10 #include "base/metrics/histogram_base.h" 11 #include "base/metrics/sample_vector.h" 12 #include "base/metrics/statistics_recorder.h" 13 #include "net/disk_cache/stats.h" 14 15 namespace disk_cache { 16 17 using base::BucketRanges; 18 using base::Histogram; 19 using base::HistogramSamples; 20 using base::SampleVector; 21 using base::StatisticsRecorder; 22 23 StatsHistogram::StatsHistogram(const std::string& name, 24 Sample minimum, 25 Sample maximum, 26 const BucketRanges* ranges, 27 const Stats* stats) 28 : Histogram(name, minimum, maximum, ranges), 29 stats_(stats) {} 30 31 StatsHistogram::~StatsHistogram() {} 32 33 // static 34 void StatsHistogram::InitializeBucketRanges(const Stats* stats, 35 BucketRanges* ranges) { 36 for (size_t i = 0; i < ranges->size(); ++i) { 37 ranges->set_range(i, stats->GetBucketRange(i)); 38 } 39 ranges->ResetChecksum(); 40 } 41 42 StatsHistogram* StatsHistogram::FactoryGet(const std::string& name, 43 const Stats* stats) { 44 Sample minimum = 1; 45 Sample maximum = disk_cache::Stats::kDataSizesLength - 1; 46 size_t bucket_count = disk_cache::Stats::kDataSizesLength; 47 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name); 48 if (!histogram) { 49 DCHECK(stats); 50 51 // To avoid racy destruction at shutdown, the following will be leaked. 52 BucketRanges* ranges = new BucketRanges(bucket_count + 1); 53 InitializeBucketRanges(stats, ranges); 54 const BucketRanges* registered_ranges = 55 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges); 56 57 // To avoid racy destruction at shutdown, the following will be leaked. 58 StatsHistogram* stats_histogram = 59 new StatsHistogram(name, minimum, maximum, registered_ranges, stats); 60 stats_histogram->SetFlags(kUmaTargetedHistogramFlag); 61 histogram = StatisticsRecorder::RegisterOrDeleteDuplicate(stats_histogram); 62 } 63 64 DCHECK(base::HISTOGRAM == histogram->GetHistogramType()); 65 DCHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count)); 66 67 // We're preparing for an otherwise unsafe upcast by ensuring we have the 68 // proper class type. 69 StatsHistogram* return_histogram = static_cast<StatsHistogram*>(histogram); 70 return return_histogram; 71 } 72 73 scoped_ptr<HistogramSamples> StatsHistogram::SnapshotSamples() const { 74 scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges())); 75 stats_->Snapshot(samples.get()); 76 77 // Only report UMA data once. 78 StatsHistogram* mutable_me = const_cast<StatsHistogram*>(this); 79 mutable_me->ClearFlags(kUmaTargetedHistogramFlag); 80 81 return samples.PassAs<HistogramSamples>(); 82 } 83 84 int StatsHistogram::FindCorruption(const HistogramSamples& samples) const { 85 // This class won't monitor inconsistencies. 86 return HistogramBase::NO_INCONSISTENCIES; 87 } 88 89 } // namespace disk_cache 90