base/metrics/histogram_flattener.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 #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
  14 namespace base {
  15
  16 class 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.
  22 class 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_