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 
SampleMap()14 SampleMap::SampleMap() : SampleMap(0) {}
15 
SampleMap(uint64_t id)16 SampleMap::SampleMap(uint64_t id) : HistogramSamples(id) {}
17 
~SampleMap()18 SampleMap::~SampleMap() {}
19 
Accumulate(Sample value,Count count)20 void SampleMap::Accumulate(Sample value, Count count) {
21   sample_counts_[value] += count;
22   IncreaseSum(count * value);
23   IncreaseRedundantCount(count);
24 }
25 
GetCount(Sample value) const26 Count 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 
TotalCount() const33 Count SampleMap::TotalCount() const {
34   Count count = 0;
35   for (const auto& entry : sample_counts_) {
36     count += entry.second;
37   }
38   return count;
39 }
40 
Iterator() const41 scoped_ptr<SampleCountIterator> SampleMap::Iterator() const {
42   return scoped_ptr<SampleCountIterator>(new SampleMapIterator(sample_counts_));
43 }
44 
AddSubtractImpl(SampleCountIterator * iter,HistogramSamples::Operator op)45 bool 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 
SampleMapIterator(const SampleToCountMap & sample_counts)60 SampleMapIterator::SampleMapIterator(const SampleToCountMap& sample_counts)
61     : iter_(sample_counts.begin()),
62       end_(sample_counts.end()) {
63   SkipEmptyBuckets();
64 }
65 
~SampleMapIterator()66 SampleMapIterator::~SampleMapIterator() {}
67 
Done() const68 bool SampleMapIterator::Done() const {
69   return iter_ == end_;
70 }
71 
Next()72 void SampleMapIterator::Next() {
73   DCHECK(!Done());
74   ++iter_;
75   SkipEmptyBuckets();
76 }
77 
Get(Sample * min,Sample * max,Count * count) const78 void 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 
SkipEmptyBuckets()88 void SampleMapIterator::SkipEmptyBuckets() {
89   while (!Done() && iter_->second == 0) {
90     ++iter_;
91   }
92 }
93 
94 }  // namespace base
95