node: fix erroneously named function call

The initial implementation of setPropByIndex() set the value of an Array
by index during development. Though the final form of the function
simply pushes passed values to an array as passed by arguments. Thus the
functions have been renamed to pushValueToArray() and
push_values_to_array_function() respectively.

Also add define for maximum number of arguments should be used before
hitting the limit of performance increase.

Fixes: 494227b "node: improve GetActiveRequests performance"
PR-URL: #3780
Reviewed-By: Fedor Indutny <fedor@indutny.com>

src/env.h

@@ -38,6 +38,12 @@ namespace node {
 #define NODE_ISOLATE_SLOT 3
 #endif
 
+// The number of items passed to push_values_to_array_function has diminishing
+// returns around 8. This should be used at all call sites using said function.
+#ifndef NODE_PUSH_VAL_TO_ARRAY_MAX
+#define NODE_PUSH_VAL_TO_ARRAY_MAX 8
+#endif
+
 // Strings are per-isolate primitives but Environment proxies them
 // for the sake of convenience.  Strings should be ASCII-only.
 #define PER_ISOLATE_STRING_PROPERTIES(V)                                      \
@@ -231,12 +237,11 @@ namespace node {
   V(zero_return_string, "ZERO_RETURN")                                        \
 
 #define ENVIRONMENT_STRONG_PERSISTENT_PROPERTIES(V)                           \
-  V(add_properties_by_index_function, v8::Function)                           \
   V(as_external, v8::External)                                                \
+  V(async_hooks_destroy_function, v8::Function)                               \
   V(async_hooks_init_function, v8::Function)                                  \
-  V(async_hooks_pre_function, v8::Function)                                   \
   V(async_hooks_post_function, v8::Function)                                  \
-  V(async_hooks_destroy_function, v8::Function)                               \
+  V(async_hooks_pre_function, v8::Function)                                   \
   V(binding_cache_object, v8::Object)                                         \
   V(buffer_constructor_function, v8::Function)                                \
   V(buffer_prototype_object, v8::Object)                                      \
@@ -250,6 +255,7 @@ namespace node {
   V(pipe_constructor_template, v8::FunctionTemplate)                          \
   V(process_object, v8::Object)                                               \
   V(promise_reject_function, v8::Function)                                    \
+  V(push_values_to_array_function, v8::Function)                              \
   V(script_context_constructor_template, v8::FunctionTemplate)                \
   V(script_data_constructor_function, v8::Function)                           \
   V(secure_context_constructor_template, v8::FunctionTemplate)                \

src/node.cc

@@ -1063,7 +1063,7 @@ void SetupProcessObject(const FunctionCallbackInfo<Value>& args) {
 
   CHECK(args[0]->IsFunction());
 
-  env->set_add_properties_by_index_function(args[0].As<Function>());
+  env->set_push_values_to_array_function(args[0].As<Function>());
   env->process_object()->Delete(
       FIXED_ONE_BYTE_STRING(env->isolate(), "_setupProcessObject"));
 }
@@ -1607,7 +1607,7 @@ static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
 
   Local<Array> ary = Array::New(args.GetIsolate());
   Local<Context> ctx = env->context();
-  Local<Function> fn = env->add_properties_by_index_function();
+  Local<Function> fn = env->push_values_to_array_function();
   static const size_t argc = 8;
   Local<Value> argv[argc];
   size_t i = 0;

src/node.js

@@ -181,9 +181,9 @@
   }
 
   startup.setupProcessObject = function() {
-    process._setupProcessObject(setPropByIndex);
+    process._setupProcessObject(pushValueToArray);
 
-    function setPropByIndex() {
+    function pushValueToArray() {
       for (var i = 0; i < arguments.length; i++)
         this.push(arguments[i]);
     }