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