base/metrics/sample_map.cc

   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
   9 namespace base {
  10
  11 typedef HistogramBase::Count Count;
  12 typedef HistogramBase::Sample Sample;
  13
  14 SampleMap::SampleMap() {}
  15
  16 SampleMap::~SampleMap() {}
  17
  18 void SampleMap::Accumulate(Sample value, Count count) {
  19   sample_counts_[value] += count;
  20   IncreaseSum(count * value);
  21   IncreaseRedundantCount(count);
  22 }
  23
  24 Count SampleMap::GetCount(Sample value) const {
  25   std::map<Sample, Count>::const_iterator it = sample_counts_.find(value);
  26   if (it == sample_counts_.end())
  27     return 0;
  28   return it->second;
  29 }
  30
  31 Count SampleMap::TotalCount() const {
  32   Count count = 0;
  33   for (const auto& entry : sample_counts_) {
  34     count += entry.second;
  35   }
  36   return count;
  37 }
  38
  39 scoped_ptr<SampleCountIterator> SampleMap::Iterator() const {
  40   return scoped_ptr<SampleCountIterator>(new SampleMapIterator(sample_counts_));
  41 }
  42
  43 bool SampleMap::AddSubtractImpl(SampleCountIterator* iter,
  44                                 HistogramSamples::Operator op) {
  45   Sample min;
  46   Sample max;
  47   Count count;
  48   for (; !iter->Done(); iter->Next()) {
  49     iter->Get(&min, &max, &count);
  50     if (min + 1 != max)
  51       return false;  // SparseHistogram only supports bucket with size 1.
  52
  53     sample_counts_[min] += (op == HistogramSamples::ADD) ? count : -count;
  54   }
  55   return true;
  56 }
  57
  58 SampleMapIterator::SampleMapIterator(const SampleToCountMap& sample_counts)
  59     : iter_(sample_counts.begin()),
  60       end_(sample_counts.end()) {
  61   SkipEmptyBuckets();
  62 }
  63
  64 SampleMapIterator::~SampleMapIterator() {}
  65
  66 bool SampleMapIterator::Done() const {
  67   return iter_ == end_;
  68 }
  69
  70 void SampleMapIterator::Next() {
  71   DCHECK(!Done());
  72   ++iter_;
  73   SkipEmptyBuckets();
  74 }
  75
  76 void SampleMapIterator::Get(Sample* min, Sample* max, Count* count) const {
  77   DCHECK(!Done());
  78   if (min != NULL)
  79     *min = iter_->first;
  80   if (max != NULL)
  81     *max = iter_->first + 1;
  82   if (count != NULL)
  83     *count = iter_->second;
  84 }
  85
  86 void SampleMapIterator::SkipEmptyBuckets() {
  87   while (!Done() && iter_->second == 0) {
  88     ++iter_;
  89   }
  90 }
  91
  92 }  // namespace base