expose counter in d8

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 7655aad4b53dfefc4f19bc3fb15d7cea965dd098..51352ab4530fe34faa3aa51f03492f7514162e86 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -599,10 +599,46 @@ Handle<ObjectTemplate> Shell::CreateGlobalTemplate() {
   AddOSMethods(os_templ);
   global_template->Set(String::New("os"), os_templ);
 

[Yang, 2011/06/29 12:02:20]

Add new object "counter".

+  Handle<ObjectTemplate> counter_templ = ObjectTemplate::New();
+  counter_templ->Set(String::New("get"),
+                     FunctionTemplate::New(GetCounterValue));
+  counter_templ->Set(String::New("names"),
+                       FunctionTemplate::New(GetCounterNames));
+  global_template->Set(String::New("counter"), counter_templ);
+
   return global_template;
 }
 
 

[Yang, 2011/06/29 12:02:20]

counter.get() returns the counter by the name provided.
e.g.
counter.get("c:V8.TotalCompiledCodeSize")

+Handle<Value> Shell::GetCounterValue(const Arguments& args) {
+  if (args.Length() != 1) {
+    return ThrowException(String::New("get() takes one argument"));
+  }
+  if (args[0]->IsString()) {
+    String::AsciiValue name(args[0]);
+    Counter* counter = counter_map_->Lookup(*name);
+    if (!counter) {
+      return ThrowException(String::New("invalid counter name"));
+    }
+    return Handle<Integer>::Cast(Integer::New(counter->count()));
+  }
+  return ThrowException(String::New("counter name must be a string"));
+}
+
+

[Yang, 2011/06/29 12:02:20]

counter.names() returns counter names as an array of strings.

+Handle<Value> Shell::GetCounterNames(const Arguments& args) {
+  if (args.Length() != 0) {
+    return ThrowException(String::New("names() takes no arguments"));
+  }
+  Handle<Array> results = Handle<Array>::Cast(Array::New(0));
+  int j = 0;
+  for (CounterMap::Iterator i(counter_map_); i.More(); i.Next()) {
+    results->Set(j++, Handle<String>::Cast(String::New(i.CurrentKey())));
+  }
+  return results;
+}
+
+
 void Shell::Initialize(bool test_shell) {
 #ifdef COMPRESS_STARTUP_DATA_BZ2
   BZip2Decompressor startup_data_decompressor;
@@ -617,11 +653,9 @@ void Shell::Initialize(bool test_shell) {
   // Set up counters
   if (i::StrLength(i::FLAG_map_counters) != 0)
     MapCounters(i::FLAG_map_counters);

[Yang, 2011/06/29 12:02:20]

Init counter in any case (not only upon --dump-counters). This makes unit tests
take less than half a second longer in total, so I think this is acceptable.

-  if (i::FLAG_dump_counters) {
-    V8::SetCounterFunction(LookupCounter);
-    V8::SetCreateHistogramFunction(CreateHistogram);
-    V8::SetAddHistogramSampleFunction(AddHistogramSample);
-  }
+  V8::SetCounterFunction(LookupCounter);
+  V8::SetCreateHistogramFunction(CreateHistogram);
+  V8::SetAddHistogramSampleFunction(AddHistogramSample);
 
   if (test_shell) return;