sample_map.cc revision 0d205d712abd16eeed2f5d5b1052a367d23a223f 
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
9namespace base {
10
11typedef HistogramBase::Count Count;
12typedef HistogramBase::Sample Sample;
13
14SampleMap::SampleMap() : SampleMap(0) {}
15
16SampleMap::SampleMap(uint64_t id) : HistogramSamples(id) {}
17
18SampleMap::~SampleMap() {}
19
20void SampleMap::Accumulate(Sample value, Count count) {
21  sample_counts_[value] += count;
22  IncreaseSum(count * value);
23  IncreaseRedundantCount(count);
24}
25
26Count SampleMap::GetCount(Sample value) const {
27  std::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
33Count SampleMap::TotalCount() const {
34  Count count = 0;
35  for (const auto& entry : sample_counts_) {
36    count += entry.second;
37  }
38  return count;
39}
40
41scoped_ptr<SampleCountIterator> SampleMap::Iterator() const {
42  return scoped_ptr<SampleCountIterator>(new SampleMapIterator(sample_counts_));
43}
44
45bool SampleMap::AddSubtractImpl(SampleCountIterator* iter,
46                                HistogramSamples::Operator op) {
47  Sample min;
48  Sample max;
49  Count count;
50  for (; !iter->Done(); iter->Next()) {
51    iter->Get(&min, &max, &count);
52    if (min + 1 != max)
53      return false;  // SparseHistogram only supports bucket with size 1.
54
55    sample_counts_[min] += (op == HistogramSamples::ADD) ? count : -count;
56  }
57  return true;
58}
59
60SampleMapIterator::SampleMapIterator(const SampleToCountMap& sample_counts)
61    : iter_(sample_counts.begin()),
62      end_(sample_counts.end()) {
63  SkipEmptyBuckets();
64}
65
66SampleMapIterator::~SampleMapIterator() {}
67
68bool SampleMapIterator::Done() const {
69  return iter_ == end_;
70}
71
72void SampleMapIterator::Next() {
73  DCHECK(!Done());
74  ++iter_;
75  SkipEmptyBuckets();
76}
77
78void SampleMapIterator::Get(Sample* min, Sample* max, Count* count) const {
79  DCHECK(!Done());
80  if (min != NULL)
81    *min = iter_->first;
82  if (max != NULL)
83    *max = iter_->first + 1;
84  if (count != NULL)
85    *count = iter_->second;
86}
87
88void SampleMapIterator::SkipEmptyBuckets() {
89  while (!Done() && iter_->second == 0) {
90    ++iter_;
91  }
92}
93
94}  // namespace base
95