base/metrics/sample_map.h

   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 // SampleMap implements HistogramSamples interface. It is used by the
   6 // SparseHistogram class to store samples.
   7
   8 #ifndef BASE_METRICS_SAMPLE_MAP_H_
   9 #define BASE_METRICS_SAMPLE_MAP_H_
  10
  11 #include <map>
  12
  13 #include "base/compiler_specific.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/metrics/histogram_base.h"
  16 #include "base/metrics/histogram_samples.h"
  17
  18 namespace base {
  19
  20 class BASE_EXPORT_PRIVATE SampleMap : public HistogramSamples {
  21  public:
  22   SampleMap();
  23   virtual ~SampleMap();
  24
  25   // HistogramSamples implementation:
  26   virtual void Accumulate(HistogramBase::Sample value,
  27                           HistogramBase::Count count) OVERRIDE;
  28   virtual HistogramBase::Count GetCount(
  29       HistogramBase::Sample value) const OVERRIDE;
  30   virtual HistogramBase::Count TotalCount() const OVERRIDE;
  31   virtual scoped_ptr<SampleCountIterator> Iterator() const OVERRIDE;
  32
  33  protected:
  34   virtual bool AddSubtractImpl(
  35       SampleCountIterator* iter,
  36       HistogramSamples::Operator op) OVERRIDE;  // |op| is ADD or SUBTRACT.
  37
  38  private:
  39   std::map<HistogramBase::Sample, HistogramBase::Count> sample_counts_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(SampleMap);
  42 };
  43
  44 class BASE_EXPORT_PRIVATE SampleMapIterator : public SampleCountIterator {
  45  public:
  46   typedef std::map<HistogramBase::Sample, HistogramBase::Count>
  47       SampleToCountMap;
  48
  49   explicit SampleMapIterator(const SampleToCountMap& sample_counts);
  50   virtual ~SampleMapIterator();
  51
  52   // SampleCountIterator implementation:
  53   virtual bool Done() const OVERRIDE;
  54   virtual void Next() OVERRIDE;
  55   virtual void Get(HistogramBase::Sample* min,
  56                    HistogramBase::Sample* max,
  57                    HistogramBase::Count* count) const OVERRIDE;
  58  private:
  59   SampleToCountMap::const_iterator iter_;
  60   const SampleToCountMap::const_iterator end_;
  61 };
  62
  63 }  // namespace base
  64
  65 #endif  // BASE_METRICS_SAMPLE_MAP_H_