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#ifndef BASE_METRICS_HISTOGRAM_FLATTENER_H_
6#define BASE_METRICS_HISTOGRAM_FLATTENER_H_
7
8#include <map>
9#include <string>
10
11#include "base/basictypes.h"
12#include "base/metrics/histogram.h"
13
14namespace base {
15
16class HistogramSamples;
17
18// HistogramFlattener is an interface used by HistogramSnapshotManager, which
19// handles the logistics of gathering up available histograms for recording.
20// The implementors handle the exact lower level recording mechanism, or
21// error report mechanism.
22class BASE_EXPORT HistogramFlattener {
23 public:
24  virtual void RecordDelta(const HistogramBase& histogram,
25                           const HistogramSamples& snapshot) = 0;
26
27  // Will be called each time a type of Inconsistency is seen on a histogram,
28  // during inspections done internally in HistogramSnapshotManager class.
29  virtual void InconsistencyDetected(HistogramBase::Inconsistency problem) = 0;
30
31  // Will be called when a type of Inconsistency is seen for the first time on
32  // a histogram.
33  virtual void UniqueInconsistencyDetected(
34      HistogramBase::Inconsistency problem) = 0;
35
36  // Will be called when the total logged sample count of a histogram
37  // differs from the sum of logged sample count in all the buckets.  The
38  // argument |amount| is the non-zero discrepancy.
39  virtual void InconsistencyDetectedInLoggedCount(int amount) = 0;
40
41 protected:
42  HistogramFlattener() {}
43  virtual ~HistogramFlattener() {}
44
45 private:
46  DISALLOW_COPY_AND_ASSIGN(HistogramFlattener);
47};
48
49}  // namespace base
50
51#endif  // BASE_METRICS_HISTOGRAM_FLATTENER_H_
52