Use TracedValue in runtime statistics.

src/counters.cc

Index: src/counters.cc
diff --git a/src/counters.cc b/src/counters.cc
index c4e86460aa1140054a09f1f0abc0a1350e4054da..7acd74a8a7f7a934ad377848bae75cc425870efa 100644
--- a/src/counters.cc
+++ b/src/counters.cc
@@ -276,11 +276,6 @@ void RuntimeCallCounter::Reset() {
   time = base::TimeDelta();
 }
 
-void RuntimeCallCounter::Dump(std::stringstream& out) {
-  out << "\"" << name << "\":[" << count << "," << time.InMicroseconds()
-      << "],";
-}
-
 // static
 void RuntimeCallStats::Enter(RuntimeCallStats* stats, RuntimeCallTimer* timer,
                              CounterId counter_id) {
@@ -364,37 +359,43 @@ void RuntimeCallStats::Reset() {
   in_use_ = true;
 }
 
-std::string RuntimeCallStats::Dump() {
-  buffer_.str(std::string());
-  buffer_.clear();
-  buffer_ << "{";
+void RuntimeCallStats::Dump(v8::tracing::TracedValue* value) {
+#define DUMP(counter)                                        \
+  if (counter.count > 0) {                                   \
+    value->BeginArray(counter.name);                         \
+    value->AppendLongInteger(counter.count);                 \
+    value->AppendLongInteger(counter.time.InMicroseconds()); \
+    value->EndArray();                                       \
+  }

[Camillo Bruni, 2016/10/18 07:52:24]

Please leave the separate function in place as the macros blow up the binary
size quite a bit :P. RuntimeCallStats::Dump easily ends up being around 80KB the
last time I measured (`nm --size-sort --print-size` is your friend).

[lpy, 2016/10/18 19:43:44]

Done.

+
 #define DUMP_COUNTER(name) \
-  if (this->name.count > 0) this->name.Dump(buffer_);
+  if (this->name.count > 0) DUMP(this->name)
   FOR_EACH_MANUAL_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name, nargs, result_size) \
-  if (this->Runtime_##name.count > 0) this->Runtime_##name.Dump(buffer_);
+  if (this->Runtime_##name.count > 0) DUMP(this->Runtime_##name);
   FOR_EACH_INTRINSIC(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->Builtin_##name.count > 0) this->Builtin_##name.Dump(buffer_);
+  if (this->Builtin_##name.count > 0) DUMP(this->Builtin_##name);
   BUILTIN_LIST_C(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->API_##name.count > 0) this->API_##name.Dump(buffer_);
+  if (this->API_##name.count > 0) DUMP(this->API_##name);
   FOR_EACH_API_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->Handler_##name.count > 0) this->Handler_##name.Dump(buffer_);
+  if (this->Handler_##name.count > 0) DUMP(this->Handler_##name);
   FOR_EACH_HANDLER_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
-  buffer_ << "\"END\":[]}";
+
   in_use_ = false;
-  return buffer_.str();
+
+#undef DUMP
 }
 
 }  // namespace internal