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// SampleVector implements HistogramSamples interface. It is used by all
6// Histogram based classes to store samples.
7
8#ifndef BASE_METRICS_SAMPLE_VECTOR_H_
9#define BASE_METRICS_SAMPLE_VECTOR_H_
10
11#include <vector>
12
13#include "base/compiler_specific.h"
14#include "base/gtest_prod_util.h"
15#include "base/memory/scoped_ptr.h"
16#include "base/metrics/histogram_base.h"
17#include "base/metrics/histogram_samples.h"
18
19namespace base {
20
21class BucketRanges;
22
23class BASE_EXPORT_PRIVATE SampleVector : public HistogramSamples {
24 public:
25  explicit SampleVector(const BucketRanges* bucket_ranges);
26  virtual ~SampleVector();
27
28  // HistogramSamples implementation:
29  virtual void Accumulate(HistogramBase::Sample value,
30                          HistogramBase::Count count) OVERRIDE;
31  virtual HistogramBase::Count GetCount(
32      HistogramBase::Sample value) const OVERRIDE;
33  virtual HistogramBase::Count TotalCount() const OVERRIDE;
34  virtual scoped_ptr<SampleCountIterator> Iterator() const OVERRIDE;
35
36  // Get count of a specific bucket.
37  HistogramBase::Count GetCountAtIndex(size_t bucket_index) const;
38
39 protected:
40  virtual bool AddSubtractImpl(
41      SampleCountIterator* iter,
42      HistogramSamples::Operator op) OVERRIDE;  // |op| is ADD or SUBTRACT.
43
44  virtual size_t GetBucketIndex(HistogramBase::Sample value) const;
45
46 private:
47  FRIEND_TEST_ALL_PREFIXES(HistogramTest, CorruptSampleCounts);
48
49  std::vector<HistogramBase::AtomicCount> counts_;
50
51  // Shares the same BucketRanges with Histogram object.
52  const BucketRanges* const bucket_ranges_;
53
54  DISALLOW_COPY_AND_ASSIGN(SampleVector);
55};
56
57class BASE_EXPORT_PRIVATE SampleVectorIterator : public SampleCountIterator {
58 public:
59  SampleVectorIterator(const std::vector<HistogramBase::AtomicCount>* counts,
60                       const BucketRanges* bucket_ranges);
61  virtual ~SampleVectorIterator();
62
63  // SampleCountIterator implementation:
64  virtual bool Done() const OVERRIDE;
65  virtual void Next() OVERRIDE;
66  virtual void Get(HistogramBase::Sample* min,
67                   HistogramBase::Sample* max,
68                   HistogramBase::Count* count) const OVERRIDE;
69
70  // SampleVector uses predefined buckets, so iterator can return bucket index.
71  virtual bool GetBucketIndex(size_t* index) const OVERRIDE;
72
73 private:
74  void SkipEmptyBuckets();
75
76  const std::vector<HistogramBase::AtomicCount>* counts_;
77  const BucketRanges* bucket_ranges_;
78
79  size_t index_;
80};
81
82}  // namespace base
83
84#endif  // BASE_METRICS_SAMPLE_VECTOR_H_
85