src: implement constants binding directly

Instead of adding a special case for it in the internal binding
loader, just implement it as usual using a per-context property
initializer.

PR-URL: #48186
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Chengzhong Wu <[email protected]>

Author: joyeecheung

src/node_binding.cc

@@ -34,6 +34,7 @@
   V(builtins)                                                                  \
   V(cares_wrap)                                                                \
   V(config)                                                                    \
+  V(constants)                                                                 \
   V(contextify)                                                                \
   V(credentials)                                                               \
   V(encoding_binding)                                                          \
@@ -619,7 +620,6 @@ void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
   Realm* realm = Realm::GetCurrent(args);
   Isolate* isolate = realm->isolate();
   HandleScope scope(isolate);
-  Local<Context> context = realm->context();
 
   CHECK(args[0]->IsString());
 
@@ -631,10 +631,6 @@ void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
   if (mod != nullptr) {
     exports = InitInternalBinding(realm, mod);
     realm->internal_bindings.insert(mod);
-  } else if (!strcmp(*module_v, "constants")) {
-    exports = Object::New(isolate);
-    CHECK(exports->SetPrototype(context, Null(isolate)).FromJust());
-    DefineConstants(isolate, exports);
   } else {
     return THROW_ERR_INVALID_MODULE(isolate, "No such binding: %s", *module_v);
   }

src/node_constants.cc

@@ -63,10 +63,14 @@
 
 namespace node {
 
+using v8::Context;
+using v8::Isolate;
 using v8::Local;
+using v8::Null;
 using v8::Object;
+using v8::Value;
 
-namespace {
+namespace constants {
 
 void DefineErrnoConstants(Local<Object> target) {
 #ifdef E2BIG
@@ -1270,10 +1274,14 @@ void DefineTraceConstants(Local<Object> target) {
   NODE_DEFINE_CONSTANT(target, TRACE_EVENT_PHASE_LINK_IDS);
 }
 
-}  // anonymous namespace
+void CreatePerContextProperties(Local<Object> target,
+                                Local<Value> unused,
+                                Local<Context> context,
+                                void* priv) {
+  Isolate* isolate = context->GetIsolate();
+  Environment* env = Environment::GetCurrent(context);
 
-void DefineConstants(v8::Isolate* isolate, Local<Object> target) {
-  Environment* env = Environment::GetCurrent(isolate);
+  CHECK(target->SetPrototype(env->context(), Null(env->isolate())).FromJust());
 
   Local<Object> os_constants = Object::New(isolate);
   CHECK(os_constants->SetPrototype(env->context(),
@@ -1353,4 +1361,8 @@ void DefineConstants(v8::Isolate* isolate, Local<Object> target) {
               trace_constants).Check();
 }
 
+}  // namespace constants
 }  // namespace node
+
+NODE_BINDING_CONTEXT_AWARE_INTERNAL(constants,
+                                    node::constants::CreatePerContextProperties)

src/node_constants.h

@@ -74,11 +74,6 @@
 #endif  // NODE_OPENSSL_DEFAULT_CIPHER_LIST
 #endif  // HAVE_OPENSSL
 
-namespace node {
-
-void DefineConstants(v8::Isolate* isolate, v8::Local<v8::Object> target);
-}  // namespace node
-
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #endif  // SRC_NODE_CONSTANTS_H_