Make code generated for histogram macros more compact.

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 <vector>
 
 #include "base/atomicops.h"
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/strings/string_piece.h"
 #include "base/time/time.h"
 
 class Pickle;
 class PickleIterator;
 
 namespace base {
 
 class DictionaryValue;
 class HistogramBase;
 class HistogramSamples;
@@ skipping 16 matching lines @@
 
 // Create or find existing histogram that matches the pickled info.
 // Returns NULL if the pickled data has problems.
 BASE_EXPORT_PRIVATE HistogramBase* DeserializeHistogramInfo(
     PickleIterator* iter);
 
 ////////////////////////////////////////////////////////////////////////////////
 
 class BASE_EXPORT HistogramBase {
  public:
-  typedef int Sample;                   // Used for samples.
-  typedef subtle::Atomic32 AtomicCount; // Used to count samples.
+  typedef int Sample;                    // Used for samples.
+  typedef subtle::Atomic32 AtomicCount;  // Used to count samples.
   typedef int32 Count;  // Used to manipulate counts in temporaries.
 
   static const Sample kSampleType_MAX;  // INT_MAX
 
   enum Flags {
     kNoFlags = 0,
 
     // Histogram should be UMA uploaded.
     kUmaTargetedHistogramFlag = 0x1,
 
@@ skipping 22 matching lines @@
     COUNT_LOW_ERROR = 0x8,
 
     NEVER_EXCEEDED_VALUE = 0x10
   };
 
   explicit HistogramBase(const std::string& name);
   virtual ~HistogramBase();
 
   std::string histogram_name() const { return histogram_name_; }
 
+  // Comapres |name| to the histogram name and triggers a DCHECK if they do not
+  // match. This is a helper function used by histogram macros, which results in
+  // in more compact machine code being generated by the macros.
+  void CheckName(const StringPiece& name) const;
+
   // Operations with Flags enum.
   int32 flags() const { return flags_; }
   void SetFlags(int32 flags);
   void ClearFlags(int32 flags);
 
   virtual HistogramType GetHistogramType() const = 0;
 
   // Whether the histogram has construction arguments as parameters specified.
   // For histograms that don't have the concept of minimum, maximum or
   // bucket_count, this function always returns false.
@@ skipping 25 matching lines @@
 
   // 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
   // customize the output.
   void WriteJSON(std::string* output) const;
 
-protected:
+ protected:
   // Subclasses should implement this function to make SerializeInfo work.
   virtual bool SerializeInfoImpl(Pickle* pickle) const = 0;
 
   // Writes information about the construction parameters in |params|.
   virtual void GetParameters(DictionaryValue* params) const = 0;
 
   // Writes information about the current (non-empty) buckets and their sample
   // counts to |buckets|, the total sample count to |count| and the total sum
   // to |sum|.
   virtual void GetCountAndBucketData(Count* count,
@@ skipping 17 matching lines @@
  private:
   const std::string histogram_name_;
   int32 flags_;
 
   DISALLOW_COPY_AND_ASSIGN(HistogramBase);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_BASE_H_