[node] switch to NodeRequest member fn callback

For (hopefully) better performance than creating a new v8::Context to
wrap each callback while still avoiding leaking memory with v8::FunctionTemplate.

Adds a JavaScript shim in front of module.exports.Map to wrap the
req.respond API internally and preserve the public callback-passing
API, while still exporting the correct prototype.

1 files changed, 6 insertions, 8 deletions

diff --git a/platform/node/src/node_request.cpp b/platform/node/src/node_request.cpp
index aa84147ad6..607e6e8b03 100644
--- a/platform/node/src/node_request.cpp
+++ b/platform/node/src/node_request.cpp
@@ -32,6 +32,8 @@ NAN_MODULE_INIT(NodeRequest::Init) {
     tpl->InstanceTemplate()->SetInternalFieldCount(1);
     tpl->SetClassName(Nan::New("Request").ToLocalChecked());
 
+    Nan::SetPrototypeMethod(tpl, "respond", HandleCallback);
+
     constructor.Reset(tpl->GetFunction());
 
     // TODO: Remove this from the public JavaScript API
@@ -49,8 +51,9 @@ void NodeRequest::New(const Nan::FunctionCallbackInfo<v8::Value>& info) {
 }
 
 void NodeRequest::HandleCallback(const Nan::FunctionCallbackInfo<v8::Value>& info) {
+    auto request = Nan::ObjectWrap::Unwrap<NodeRequest>(info.Holder());
+
     // Move out of the object so callback() can only be fired once.
-    auto request = Nan::ObjectWrap::Unwrap<NodeRequest>(info.Data().As<v8::Object>());
     auto callback = std::move(request->callback);
     if (!callback) {
         return info.GetReturnValue().SetUndefined();
@@ -122,14 +125,9 @@ void NodeRequest::HandleCallback(const Nan::FunctionCallbackInfo<v8::Value>& inf
 }
 
 void NodeRequest::Execute() {
-    // Enter a new v8::Context to avoid leaking v8::FunctionTemplate
-    // from Nan::New<v8::Function>
-    v8::Local<v8::Context> context = v8::Context::New(v8::Isolate::GetCurrent());
-    v8::Context::Scope scope(context);
-
-    v8::Local<v8::Value> argv[] = { handle(), Nan::New<v8::Function>(NodeRequest::HandleCallback, handle()) };
+    v8::Local<v8::Value> argv[] = { handle() };
 
-    Nan::MakeCallback(Nan::To<v8::Object>(target->handle()->GetInternalField(1)).ToLocalChecked(), "request", 2, argv);
+    Nan::MakeCallback(Nan::To<v8::Object>(target->handle()->GetInternalField(1)).ToLocalChecked(), "request", 1, argv);
 }
 
 NodeRequest::NodeAsyncRequest::NodeAsyncRequest(NodeRequest* request_) : request(request_) {