chrome/renderer/benchmarking_extension.cc

   1 // Copyright (c) 2011 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 #include "chrome/renderer/benchmarking_extension.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/metrics/stats_table.h"
   9 #include "base/time/time.h"
  10 #include "content/public/common/content_switches.h"
  11 #include "content/public/renderer/render_thread.h"
  12 #include "v8/include/v8.h"
  13
  14 const char kBenchmarkingExtensionName[] = "v8/Benchmarking";
  15
  16 namespace extensions_v8 {
  17
  18 class BenchmarkingWrapper : public v8::Extension {
  19  public:
  20   BenchmarkingWrapper() :
  21       v8::Extension(kBenchmarkingExtensionName,
  22         "if (typeof(chrome) == 'undefined') {"
  23         "  chrome = {};"
  24         "};"
  25         "if (typeof(chrome.benchmarking) == 'undefined') {"
  26         "  chrome.benchmarking = {};"
  27         "};"
  28         "chrome.benchmarking.counter = function(name) {"
  29         "  native function GetCounter();"
  30         "  return GetCounter(name);"
  31         "};"
  32         "chrome.benchmarking.isSingleProcess = function() {"
  33         "  native function IsSingleProcess();"
  34         "  return IsSingleProcess();"
  35         "};"
  36         "chrome.Interval = function() {"
  37         "  var start_ = 0;"
  38         "  var stop_ = 0;"
  39         "  native function HiResTime();"
  40         "  this.start = function() {"
  41         "    stop_ = 0;"
  42         "    start_ = HiResTime();"
  43         "  };"
  44         "  this.stop = function() {"
  45         "    stop_ = HiResTime();"
  46         "    if (start_ == 0)"
  47         "      stop_ = 0;"
  48         "  };"
  49         "  this.microseconds = function() {"
  50         "    var stop = stop_;"
  51         "    if (stop == 0 && start_ != 0)"
  52         "      stop = HiResTime();"
  53         "    return Math.ceil(stop - start_);"
  54         "  };"
  55         "}"
  56         ) {}
  57
  58   virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
  59       v8::Handle<v8::String> name) OVERRIDE {
  60     if (name->Equals(v8::String::New("GetCounter"))) {
  61       return v8::FunctionTemplate::New(GetCounter);
  62     } else if (name->Equals(v8::String::New("IsSingleProcess"))) {
  63       return v8::FunctionTemplate::New(IsSingleProcess);
  64     } else if (name->Equals(v8::String::New("HiResTime"))) {
  65       return v8::FunctionTemplate::New(HiResTime);
  66     }
  67
  68     return v8::Handle<v8::FunctionTemplate>();
  69   }
  70
  71   static void GetCounter(const v8::FunctionCallbackInfo<v8::Value>& args) {
  72     if (!args.Length() || !args[0]->IsString() || !base::StatsTable::current())
  73       return;
  74
  75     // Extract the name argument
  76     char name[256];
  77     name[0] = 'c';
  78     name[1] = ':';
  79     args[0]->ToString()->WriteUtf8(&name[2], sizeof(name) - 3);
  80
  81     int counter = base::StatsTable::current()->GetCounterValue(name);
  82     args.GetReturnValue().Set(static_cast<int32_t>(counter));
  83   }
  84
  85   static void IsSingleProcess(const v8::FunctionCallbackInfo<v8::Value>& args) {
  86     args.GetReturnValue().Set(
  87        CommandLine::ForCurrentProcess()->HasSwitch(switches::kSingleProcess));
  88   }
  89
  90   static void HiResTime(const v8::FunctionCallbackInfo<v8::Value>& args) {
  91     args.GetReturnValue().Set(
  92         static_cast<double>(base::TimeTicks::HighResNow().ToInternalValue()));
  93   }
  94 };
  95
  96 v8::Extension* BenchmarkingExtension::Get() {
  97   return new BenchmarkingWrapper();
  98 }
  99
 100 }  // namespace extensions_v8