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 "base/metrics/sample_map.h" 6 7 #include "base/logging.h" 8 #include "base/memory/ptr_util.h" 9 #include "base/stl_util.h" 10 11 namespace base { 12 13 typedef HistogramBase::Count Count; 14 typedef HistogramBase::Sample Sample; 15 16 namespace { 17 18 // An iterator for going through a SampleMap. The logic here is identical 19 // to that of PersistentSampleMapIterator but with different data structures. 20 // Changes here likely need to be duplicated there. 21 class SampleMapIterator : public SampleCountIterator { 22 public: 23 typedef std::map<HistogramBase::Sample, HistogramBase::Count> 24 SampleToCountMap; 25 26 explicit SampleMapIterator(const SampleToCountMap& sample_counts); 27 ~SampleMapIterator() override; 28 29 // SampleCountIterator: 30 bool Done() const override; 31 void Next() override; 32 void Get(HistogramBase::Sample* min, 33 HistogramBase::Sample* max, 34 HistogramBase::Count* count) const override; 35 36 private: 37 void SkipEmptyBuckets(); 38 39 SampleToCountMap::const_iterator iter_; 40 const SampleToCountMap::const_iterator end_; 41 }; 42 43 SampleMapIterator::SampleMapIterator(const SampleToCountMap& sample_counts) 44 : iter_(sample_counts.begin()), 45 end_(sample_counts.end()) { 46 SkipEmptyBuckets(); 47 } 48 49 SampleMapIterator::~SampleMapIterator() {} 50 51 bool SampleMapIterator::Done() const { 52 return iter_ == end_; 53 } 54 55 void SampleMapIterator::Next() { 56 DCHECK(!Done()); 57 ++iter_; 58 SkipEmptyBuckets(); 59 } 60 61 void SampleMapIterator::Get(Sample* min, Sample* max, Count* count) const { 62 DCHECK(!Done()); 63 if (min) 64 *min = iter_->first; 65 if (max) 66 *max = iter_->first + 1; 67 if (count) 68 *count = iter_->second; 69 } 70 71 void SampleMapIterator::SkipEmptyBuckets() { 72 while (!Done() && iter_->second == 0) { 73 ++iter_; 74 } 75 } 76 77 } // namespace 78 79 SampleMap::SampleMap() : SampleMap(0) {} 80 81 SampleMap::SampleMap(uint64_t id) : HistogramSamples(id) {} 82 83 SampleMap::~SampleMap() {} 84 85 void SampleMap::Accumulate(Sample value, Count count) { 86 sample_counts_[value] += count; 87 IncreaseSum(static_cast<int64_t>(count) * value); 88 IncreaseRedundantCount(count); 89 } 90 91 Count SampleMap::GetCount(Sample value) const { 92 std::map<Sample, Count>::const_iterator it = sample_counts_.find(value); 93 if (it == sample_counts_.end()) 94 return 0; 95 return it->second; 96 } 97 98 Count SampleMap::TotalCount() const { 99 Count count = 0; 100 for (const auto& entry : sample_counts_) { 101 count += entry.second; 102 } 103 return count; 104 } 105 106 std::unique_ptr<SampleCountIterator> SampleMap::Iterator() const { 107 return WrapUnique(new SampleMapIterator(sample_counts_)); 108 } 109 110 bool SampleMap::AddSubtractImpl(SampleCountIterator* iter, Operator op) { 111 Sample min; 112 Sample max; 113 Count count; 114 for (; !iter->Done(); iter->Next()) { 115 iter->Get(&min, &max, &count); 116 if (min + 1 != max) 117 return false; // SparseHistogram only supports bucket with size 1. 118 119 sample_counts_[min] += (op == HistogramSamples::ADD) ? count : -count; 120 } 121 return true; 122 } 123 124 } // namespace base 125