Reenable d8 stats timers, using the histogram mechanism

src/d8.h

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 24 matching lines @@
 namespace v8 {
 
 
 namespace i = v8::internal;
 
 
 // A single counter in a counter collection.
 class Counter {
  public:
   static const int kMaxNameSize = 64;
-  int32_t* Bind(const char* name);
-  int32_t* ptr() { return &counter_; }
-  int32_t value() { return counter_; }
+  int32_t* Bind(const char* name, bool histogram);
+  int32_t* ptr() { return &count_; }
+  int32_t count() { return count_; }
+  int32_t sample_total() { return sample_total_; }
+  bool is_histogram() { return is_histogram_; }
+  void AddSample(int32_t sample);
  private:
-  int32_t counter_;
+  int32_t count_;
+  int32_t sample_total_;
+  bool is_histogram_;
   uint8_t name_[kMaxNameSize];
 };
 
 
 // A set of counters and associated information.  An instance of this
 // class is stored directly in the memory-mapped counters file if
 // the --map-counters options is used
 class CounterCollection {
  public:
   CounterCollection();
@@ skipping 49 matching lines @@
 class Shell: public i::AllStatic {
  public:
   static bool ExecuteString(Handle<String> source,
                             Handle<Value> name,
                             bool print_result,
                             bool report_exceptions);
   static void ReportException(TryCatch* try_catch);
   static void Initialize();
   static void OnExit();
   static int* LookupCounter(const char* name);
+  static void* CreateHistogram(const char* name,
+                               int min,
+                               int max,
+                               size_t buckets);
+  static void AddHistogramSample(void* histogram, int sample);
   static void MapCounters(const char* name);
   static Handle<String> ReadFile(const char* name);
   static void RunShell();
   static int Main(int argc, char* argv[]);
   static Handle<Array> GetCompletions(Handle<String> text,
                                       Handle<String> full);
   static Handle<Object> DebugMessageDetails(Handle<String> message);
   static Handle<Value> DebugCommandToJSONRequest(Handle<String> command);
 
   static Handle<Value> Print(const Arguments& args);
@@ skipping 43 matching lines @@
   static const char* kPrompt;
  private:
   static Persistent<Context> utility_context_;
   static Persistent<Context> evaluation_context_;
   static CounterMap* counter_map_;
   // We statically allocate a set of local counters to be used if we
   // don't want to store the stats in a memory-mapped file
   static CounterCollection local_counters_;
   static CounterCollection* counters_;
   static i::OS::MemoryMappedFile* counters_file_;
+  static Counter* GetCounter(const char* name, bool is_histogram);
 };
 
 
 class LineEditor {
  public:
   enum Type { DUMB = 0, READLINE = 1 };
   LineEditor(Type type, const char* name);
   virtual ~LineEditor() { }
 
   virtual i::SmartPointer<char> Prompt(const char* prompt) = 0;
   virtual bool Open() { return true; }
   virtual bool Close() { return true; }
   virtual void AddHistory(const char* str) { }
 
   const char* name() { return name_; }
   static LineEditor* Get();
  private:
   Type type_;
   const char* name_;
   LineEditor* next_;
   static LineEditor* first_;
 };
 
 
 }  // namespace v8
 
 
 #endif  // V8_D8_H_