src/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.counterForRenderer = function(name) {"
  33         "  native function GetCounterForRenderer();"
  34         "  return GetCounterForRenderer(name);"
  35         "};"
  36         "chrome.benchmarking.isSingleProcess = function() {"
  37         "  native function IsSingleProcess();"
  38         "  return IsSingleProcess();"
  39         "};"
  40         "chrome.Interval = function() {"
  41         "  var start_ = 0;"
  42         "  var stop_ = 0;"
  43         "  native function HiResTime();"
  44         "  this.start = function() {"
  45         "    stop_ = 0;"
  46         "    start_ = HiResTime();"
  47         "  };"
  48         "  this.stop = function() {"
  49         "    stop_ = HiResTime();"
  50         "    if (start_ == 0)"
  51         "      stop_ = 0;"
  52         "  };"
  53         "  this.microseconds = function() {"
  54         "    var stop = stop_;"
  55         "    if (stop == 0 && start_ != 0)"
  56         "      stop = HiResTime();"
  57         "    return Math.ceil(stop - start_);"
  58         "  };"
  59         "}"
  60         ) {}
  61
  62   v8::Handle<v8::FunctionTemplate> GetNativeFunctionTemplate(
  63       v8::Isolate* isolate,
  64       v8::Handle<v8::String> name) override {
  65     if (name->Equals(v8::String::NewFromUtf8(isolate, "GetCounter"))) {
  66       return v8::FunctionTemplate::New(isolate, GetCounter);
  67     } else if (name->Equals(
  68                    v8::String::NewFromUtf8(isolate, "GetCounterForRenderer"))) {
  69       return v8::FunctionTemplate::New(isolate, GetCounterForRenderer);
  70     } else if (name->Equals(
  71                    v8::String::NewFromUtf8(isolate, "IsSingleProcess"))) {
  72       return v8::FunctionTemplate::New(isolate, IsSingleProcess);
  73     } else if (name->Equals(v8::String::NewFromUtf8(isolate, "HiResTime"))) {
  74       return v8::FunctionTemplate::New(isolate, HiResTime);
  75     }
  76
  77     return v8::Handle<v8::FunctionTemplate>();
  78   }
  79
  80   /*
  81    * Extract the counter name from arguments.
  82    */
  83   static void ExtractCounterName(
  84       const v8::FunctionCallbackInfo<v8::Value>& args,
  85       char* name,
  86       size_t capacity) {
  87     name[0] = 'c';
  88     name[1] = ':';
  89     args[0]->ToString()->WriteUtf8(&name[2], capacity - 3);
  90   }
  91
  92   static void GetCounter(const v8::FunctionCallbackInfo<v8::Value>& args) {
  93     if (!args.Length() || !args[0]->IsString() || !base::StatsTable::current())
  94       return;
  95
  96     char name[256];
  97     ExtractCounterName(args, name, sizeof(name));
  98     int counter = base::StatsTable::current()->GetCounterValue(name);
  99     args.GetReturnValue().Set(static_cast<int32_t>(counter));
 100   }
 101
 102   static void GetCounterForRenderer(
 103       const v8::FunctionCallbackInfo<v8::Value>& args) {
 104     if (!args.Length() || !args[0]->IsString() || !base::StatsTable::current())
 105       return;
 106
 107     char name[256];
 108     ExtractCounterName(args, name, sizeof(name));
 109     int counter = base::StatsTable::current()->GetCounterValue(
 110         name,
 111         base::GetCurrentProcId());
 112     args.GetReturnValue().Set(static_cast<int32_t>(counter));
 113   }
 114
 115   static void IsSingleProcess(const v8::FunctionCallbackInfo<v8::Value>& args) {
 116     args.GetReturnValue().Set(
 117        CommandLine::ForCurrentProcess()->HasSwitch(switches::kSingleProcess));
 118   }
 119
 120   static void HiResTime(const v8::FunctionCallbackInfo<v8::Value>& args) {
 121     args.GetReturnValue().Set(
 122         static_cast<double>(base::TimeTicks::HighResNow().ToInternalValue()));
 123   }
 124 };
 125
 126 v8::Extension* BenchmarkingExtension::Get() {
 127   return new BenchmarkingWrapper();
 128 }
 129
 130 }  // namespace extensions_v8