Connect SparseHistogram with the rest of stats system

base/metrics/histogram.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Histogram is an object that aggregates statistics, and can summarize them in
 // various forms, including ASCII graphical, HTML, and numerically (as a
 // vector of numbers corresponding to each of the aggregating buckets).
 
 // It supports calls to accumulate either time intervals (which are processed
 // as integral number of milliseconds), or arbitrary integral units.
@@ skipping 351 matching lines @@
 class Histogram;
 class LinearHistogram;
 
 class BASE_EXPORT Histogram : public HistogramBase {
  public:
   // Initialize maximum number of buckets in histograms as 16,384.
   static const size_t kBucketCount_MAX;
 
   typedef std::vector<Count> Counts;
 
-  enum Inconsistencies {
-    NO_INCONSISTENCIES = 0x0,
-    RANGE_CHECKSUM_ERROR = 0x1,
-    BUCKET_ORDER_ERROR = 0x2,
-    COUNT_HIGH_ERROR = 0x4,
-    COUNT_LOW_ERROR = 0x8,
-
-    NEVER_EXCEEDED_VALUE = 0x10
-  };
-
   //----------------------------------------------------------------------------
   // For a valid histogram, input should follow these restrictions:
   // minimum > 0 (if a minimum below 1 is specified, it will implicitly be
   //              normalized up to 1)
   // maximum > minimum
   // buckets > 2 [minimum buckets needed: underflow, overflow and the range]
   // Additionally,
   // buckets <= (maximum - minimum + 2) - this is to ensure that we don't have
   // more buckets than the range of numbers; having more buckets than 1 per
   // value in the range would be nonsensical.
@@ skipping 24 matching lines @@
   // certain amount of slop before flagging this as an inconsistency. Even with
   // an inconsistency, we'll snapshot it again (for UMA in about a half hour),
   // so we'll eventually get the data, if it was not the result of a corruption.
   static const int kCommonRaceBasedCountMismatch;
 
   // Check to see if bucket ranges, counts and tallies in the snapshot are
   // consistent with the bucket ranges and checksums in our histogram.  This can
   // produce a false-alarm if a race occurred in the reading of the data during
   // a SnapShot process, but should otherwise be false at all times (unless we
   // have memory over-writes, or DRAM failures).
-  virtual Inconsistencies FindCorruption(const HistogramSamples& samples) const;
+  virtual int FindCorruption(const HistogramSamples& samples) const OVERRIDE;

[brettw, 2013/02/28 22:56:25]

This should be moved to the HistogramBase overrides section (and you can delete
the comment). Does this comment need to be moved to the base class? There's some
stuff about race conditions.

[kaiwang, 2013/03/01 00:52:12]

This function is not pure virtual in HistogramBase, and this comment is only for
Histogram corruption. This is way I keep it in this way...

 
   //----------------------------------------------------------------------------
   // Accessors for factory constuction, serialization and testing.
   //----------------------------------------------------------------------------
   Sample declared_min() const { return declared_min_; }
   Sample declared_max() const { return declared_max_; }
   virtual Sample ranges(size_t i) const;
   virtual size_t bucket_count() const;
   const BucketRanges* bucket_ranges() const { return bucket_ranges_; }
 
@@ skipping 251 matching lines @@
   static bool ValidateCustomRanges(const std::vector<Sample>& custom_ranges);
   static BucketRanges* CreateBucketRangesFromCustomRanges(
       const std::vector<Sample>& custom_ranges);
 
   DISALLOW_COPY_AND_ASSIGN(CustomHistogram);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_H_