src: add Addon<T> class

* separate out instance-related APIs from `ObjectWrap<T>` into a new
class `InstanceWrap<T>` which then becomes a base class for
`ObjectWrap<T>`.
* Add `Addon<T>` class as a subclass of `InstanceWrap<T>`,
reimplementing `Unwrap()` to retrieve the instance data using
`GetInstanceData<T>()` of `Napi::Env` instead of `napi_unwrap()`.
* Add macros `NODE_API_ADDON()` and `NODE_API_NAMED_ADDON()` to load an
add-on from its `Addon<T>` subclass definition.
Bindings created like this perform slightly worse than static ones in
exchange for the benefit of having the context of a class instance as
their C++ `this` object. This way, they avoid having to call
`info.GetInstanceData<ClassName>()` in the bindings, which brings with
it the risk that the wrong `ClassName` will end up in the template
parameter thus resulting in a hard-to-track-down segfault. Static
bindings can still be created and associated with the `exports` object
and they can use `Napi::Env::GetInstanceData()` to retrieve the add-on
instance.
PR-URL: #749
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

Author: Gabriel Schulhof

README.md

@@ -77,6 +77,7 @@ The oldest Node.js version supported by the current version of node-addon-api is
 
 The following is the documentation for node-addon-api.
 
+-[Addon Structure](doc/addon.md)
 -[Basic Types](doc/basic_types.md)
 -[Array](doc/basic_types.md#array)
 -[Symbol](doc/symbol.md)

benchmark/function_args.cc

@@ -78,6 +78,66 @@ static void FourArgFunction(const Napi::CallbackInfo& info) {
  Napi::Value argv3 = info[3]; (void) argv3;
 }
 
+#if NAPI_VERSION > 5
+classFunctionArgsBenchmark : publicNapi::Addon<FunctionArgsBenchmark> {
+public:
+FunctionArgsBenchmark(Napi::Env env, Napi::Object exports) {
+DefineAddon(exports, {
+InstanceValue("addon", DefineProperties(Napi::Object::New(env), {
+InstanceMethod("noArgFunction", &FunctionArgsBenchmark::NoArgFunction),
+InstanceMethod("oneArgFunction",
+ &FunctionArgsBenchmark::OneArgFunction),
+InstanceMethod("twoArgFunction",
+ &FunctionArgsBenchmark::TwoArgFunction),
+InstanceMethod("threeArgFunction",
+ &FunctionArgsBenchmark::ThreeArgFunction),
+InstanceMethod("fourArgFunction",
+ &FunctionArgsBenchmark::FourArgFunction),
+ }), napi_enumerable),
+InstanceValue("addon_templated",
+DefineProperties(Napi::Object::New(env), {
+ InstanceMethod<&FunctionArgsBenchmark::NoArgFunction>(
+"noArgFunction"),
+ InstanceMethod<&FunctionArgsBenchmark::OneArgFunction>(
+"oneArgFunction"),
+ InstanceMethod<&FunctionArgsBenchmark::TwoArgFunction>(
+"twoArgFunction"),
+ InstanceMethod<&FunctionArgsBenchmark::ThreeArgFunction>(
+"threeArgFunction"),
+ InstanceMethod<&FunctionArgsBenchmark::FourArgFunction>(
+"fourArgFunction"),
+ }), napi_enumerable),
+ });
+ }
+private:
+voidNoArgFunction(const Napi::CallbackInfo& info) {
+ (void) info;
+ }
+
+voidOneArgFunction(const Napi::CallbackInfo& info) {
+ Napi::Value argv0 = info[0]; (void) argv0;
+ }
+
+voidTwoArgFunction(const Napi::CallbackInfo& info) {
+ Napi::Value argv0 = info[0]; (void) argv0;
+ Napi::Value argv1 = info[1]; (void) argv1;
+ }
+
+voidThreeArgFunction(const Napi::CallbackInfo& info) {
+ Napi::Value argv0 = info[0]; (void) argv0;
+ Napi::Value argv1 = info[1]; (void) argv1;
+ Napi::Value argv2 = info[2]; (void) argv2;
+ }
+
+voidFourArgFunction(const Napi::CallbackInfo& info) {
+ Napi::Value argv0 = info[0]; (void) argv0;
+ Napi::Value argv1 = info[1]; (void) argv1;
+ Napi::Value argv2 = info[2]; (void) argv2;
+ Napi::Value argv3 = info[3]; (void) argv3;
+ }
+};
+#endif// NAPI_VERSION > 5
+
 static Napi::Object Init(Napi::Env env, Napi::Object exports) {
  napi_value no_arg_function, one_arg_function, two_arg_function,
  three_arg_function, four_arg_function;
@@ -147,6 +207,10 @@ static Napi::Object Init(Napi::Env env, Napi::Object exports) {
  templated["fourArgFunction"] = Napi::Function::New<FourArgFunction>(env);
  exports["templated"] = templated;
 
+#if NAPI_VERSION > 5
+FunctionArgsBenchmark::Init(env, exports);
+#endif// NAPI_VERSION > 5
+
 return exports;
 }
 

benchmark/function_args.js

@@ -4,48 +4,56 @@ const addonName = path.basename(__filename, '.js');
 
 [addonName,addonName+'_noexcept']
 .forEach((addonName)=>{
-constrootAddon=require(`./build/Release/${addonName}`);
+constrootAddon=require('bindings')({
+bindings: addonName,
+module_root: __dirname
+});
+deleterootAddon.path;
 constimplems=Object.keys(rootAddon);
+constmaxNameLength=
+implems.reduce((soFar,value)=>Math.max(soFar,value.length),0);
 constanObject={};
 
-console.log(`${addonName}: `);
+console.log(`\n${addonName}: `);
 
 console.log('no arguments:');
 implems.reduce((suite,implem)=>{
 constfn=rootAddon[implem].noArgFunction;
-returnsuite.add(implem,()=>fn());
+returnsuite.add(implem.padStart(maxNameLength,' '),()=>fn());
 },newBenchmark.Suite)
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();
 
 console.log('one argument:');
 implems.reduce((suite,implem)=>{
 constfn=rootAddon[implem].oneArgFunction;
-returnsuite.add(implem,()=>fn('x'));
+returnsuite.add(implem.padStart(maxNameLength,' '),()=>fn('x'));
 },newBenchmark.Suite)
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();
 
 console.log('two arguments:');
 implems.reduce((suite,implem)=>{
 constfn=rootAddon[implem].twoArgFunction;
-returnsuite.add(implem,()=>fn('x',12));
+returnsuite.add(implem.padStart(maxNameLength,' '),()=>fn('x',12));
 },newBenchmark.Suite)
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();
 
 console.log('three arguments:');
 implems.reduce((suite,implem)=>{
 constfn=rootAddon[implem].threeArgFunction;
-returnsuite.add(implem,()=>fn('x',12,true));
+returnsuite.add(implem.padStart(maxNameLength,' '),
+()=>fn('x',12,true));
 },newBenchmark.Suite)
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();
 
 console.log('four arguments:');
 implems.reduce((suite,implem)=>{
 constfn=rootAddon[implem].fourArgFunction;
-returnsuite.add(implem,()=>fn('x',12,true,anObject));
+returnsuite.add(implem.padStart(maxNameLength,' '),
+()=>fn('x',12,true,anObject));
 },newBenchmark.Suite)
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();

benchmark/property_descriptor.cc

@@ -26,6 +26,33 @@ static void Setter(const Napi::CallbackInfo& info) {
  (void) info[0];
 }
 
+#if NAPI_VERSION > 5
+classPropDescBenchmark : publicNapi::Addon<PropDescBenchmark> {
+public:
+PropDescBenchmark(Napi::Env, Napi::Object exports) {
+DefineAddon(exports, {
+InstanceAccessor("addon",
+ &PropDescBenchmark::Getter,
+ &PropDescBenchmark::Setter,
+ napi_enumerable),
+ InstanceAccessor<&PropDescBenchmark::Getter,
+ &PropDescBenchmark::Setter>("addon_templated",
+ napi_enumerable),
+ });
+ }
+
+private:
+ Napi::Value Getter(const Napi::CallbackInfo& info) {
+returnNapi::Number::New(info.Env(), 42);
+ }
+
+voidSetter(const Napi::CallbackInfo& info, const Napi::Value& val) {
+ (void) info[0];
+ (void) val;
+ }
+};
+#endif// NAPI_VERSION > 5
+
 static Napi::Object Init(Napi::Env env, Napi::Object exports) {
  napi_status status;
  napi_property_descriptor core_prop = {
@@ -54,6 +81,10 @@ static Napi::Object Init(Napi::Env env, Napi::Object exports) {
  Napi::PropertyDescriptor::Accessor<Getter, Setter>("templated",
  napi_enumerable));
 
+#if NAPI_VERSION > 5
+PropDescBenchmark::Init(env, exports);
+#endif// NAPI_VERSION > 5
+
 return exports;
 }
 

benchmark/property_descriptor.js

@@ -4,17 +4,23 @@ const addonName = path.basename(__filename, '.js');
 
 [addonName,addonName+'_noexcept']
 .forEach((addonName)=>{
-constrootAddon=require(`./build/Release/${addonName}`);
+constrootAddon=require('bindings')({
+bindings: addonName,
+module_root: __dirname
+});
+deleterootAddon.path;
 constgetters=newBenchmark.Suite;
 constsetters=newBenchmark.Suite;
+constmaxNameLength=Object.keys(rootAddon)
+.reduce((soFar,value)=>Math.max(soFar,value.length),0);
 
-console.log(`${addonName}: `);
+console.log(`\n${addonName}: `);
 
 Object.keys(rootAddon).forEach((key)=>{
-getters.add(`${key} getter`,()=>{
+getters.add(`${key} getter`.padStart(maxNameLength+7),()=>{
 constx=rootAddon[key];
 });
-setters.add(`${key} setter`,()=>{
+setters.add(`${key} setter`.padStart(maxNameLength+7),()=>{
 rootAddon[key]=5;
 })
 });
@@ -23,6 +29,8 @@ const addonName = path.basename(__filename, '.js');
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();
 
+console.log('');
+
 setters
 .on('cycle',(event)=>console.log(String(event.target)))
 .run();