Connect SparseHistogram with the rest of stats system

base/metrics/histogram_base.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.
 
 #ifndef BASE_METRICS_HISTOGRAM_BASE_H_
 #define BASE_METRICS_HISTOGRAM_BASE_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 30 matching lines @@
 // Returns NULL if the pickled data has problems.
 BASE_EXPORT_PRIVATE HistogramBase* DeserializeHistogramInfo(
     PickleIterator* iter);
 
 // Create or find existing histogram and add the samples from pickle.
 // Silently returns when seeing any data problem in the pickle.
 BASE_EXPORT void DeserializeHistogramAndAddSamples(PickleIterator* iter);
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// Histogram data inconsistency types.
+enum BASE_EXPORT HistogramInconsistency {
+  NO_INCONSISTENCIES = 0x0,

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

This creates things named base::COUNT_LOW_ERROR, for example, which isn't
sufficiently unique or self-documenting. Either this should be a member of
HistogramBase or it needs some kind of unique prefix. I'd do the member like it
used to be in Histogram.

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

Done.

+  RANGE_CHECKSUM_ERROR = 0x1,
+  BUCKET_ORDER_ERROR = 0x2,
+  COUNT_HIGH_ERROR = 0x4,
+  COUNT_LOW_ERROR = 0x8,
+
+  NEVER_EXCEEDED_VALUE = 0x10
+};
+
 class BASE_EXPORT HistogramBase {
  public:
   typedef int Sample;  // Used for samples.
   typedef int Count;   // Used to count samples.
 
   static const Sample kSampleType_MAX;  // INT_MAX
 
   enum Flags {
     kNoFlags = 0,
     kUmaTargetedHistogramFlag = 0x1,  // Histogram should be UMA uploaded.
@@ skipping 35 matching lines @@
   void AddBoolean(bool value);
 
   virtual void AddSamples(const HistogramSamples& samples) = 0;
   virtual bool AddSamplesFromPickle(PickleIterator* iter) = 0;
 
   // Serialize the histogram info into |pickle|.
   // Note: This only serializes the construction arguments of the histogram, but
   // does not serialize the samples.
   bool SerializeInfo(Pickle* pickle) const;
 
+  // Try to find out data corruption from histogram and the samples.
+  // The returned value is a combination of HistogramInconsistency enum.
+  virtual int FindCorruption(const HistogramSamples& samples) const;
+
   // Snapshot the current complete set of sample data.
   // Override with atomic/locked snapshot if needed.
   virtual scoped_ptr<HistogramSamples> SnapshotSamples() const = 0;
 
   // The following methods provide graphical histogram displays.
   virtual void WriteHTMLGraph(std::string* output) const = 0;
   virtual void WriteAscii(std::string* output) const = 0;
 
   // Produce a JSON representation of the histogram. This is implemented with
   // the help of GetParameters and GetCountAndBucketData; overwrite them to
@@ skipping 14 matching lines @@
  private:
   const std::string histogram_name_;
   int32 flags_;
 
   DISALLOW_COPY_AND_ASSIGN(HistogramBase);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_BASE_H_