1 #include "../common.h"
2 #include "../entry_point.h"
3 #include "assert.h"
4 #include "myobject.h"
5 
6 napi_ref MyObject::constructor;
7 
MyObject(double value)8 MyObject::MyObject(double value)
9     : value_(value), env_(nullptr), wrapper_(nullptr) {}
10 
~MyObject()11 MyObject::~MyObject() { napi_delete_reference(env_, wrapper_); }
12 
Destructor( napi_env env, void* nativeObject, void* )13 void MyObject::Destructor(
14   napi_env env, void* nativeObject, void* /*finalize_hint*/) {
15   MyObject* obj = static_cast<MyObject*>(nativeObject);
16   delete obj;
17 }
18 
Init(napi_env env, napi_value exports)19 void MyObject::Init(napi_env env, napi_value exports) {
20   napi_property_descriptor properties[] = {
21     { "value", nullptr, nullptr, GetValue, SetValue, 0, napi_default, 0 },
22     { "valueReadonly", nullptr, nullptr, GetValue, nullptr, 0, napi_default,
23       0 },
24     DECLARE_NODE_API_PROPERTY("plusOne", PlusOne),
25     DECLARE_NODE_API_PROPERTY("multiply", Multiply),
26   };
27 
28   napi_value cons;
29   NODE_API_CALL_RETURN_VOID(env, napi_define_class(
30       env, "MyObject", -1, New, nullptr,
31       sizeof(properties) / sizeof(napi_property_descriptor),
32       properties, &cons));
33 
34   NODE_API_CALL_RETURN_VOID(env,
35       napi_create_reference(env, cons, 1, &constructor));
36 
37   NODE_API_CALL_RETURN_VOID(env,
38       napi_set_named_property(env, exports, "MyObject", cons));
39 }
40 
New(napi_env env, napi_callback_info info)41 napi_value MyObject::New(napi_env env, napi_callback_info info) {
42   napi_value new_target;
43   NODE_API_CALL(env, napi_get_new_target(env, info, &new_target));
44   bool is_constructor = (new_target != nullptr);
45 
46   size_t argc = 1;
47   napi_value args[1];
48   napi_value _this;
49   NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, &_this, nullptr));
50 
51   if (is_constructor) {
52     // Invoked as constructor: `new MyObject(...)`
53     double value = 0;
54 
55     napi_valuetype valuetype;
56     NODE_API_CALL(env, napi_typeof(env, args[0], &valuetype));
57 
58     if (valuetype != napi_undefined) {
59       NODE_API_CALL(env, napi_get_value_double(env, args[0], &value));
60     }
61 
62     MyObject* obj = new MyObject(value);
63 
64     obj->env_ = env;
65     NODE_API_CALL(env,
66         napi_wrap(env, _this, obj, MyObject::Destructor,
67             nullptr /* finalize_hint */, &obj->wrapper_));
68 
69     return _this;
70   }
71 
72   // Invoked as plain function `MyObject(...)`, turn into construct call.
73   argc = 1;
74   napi_value argv[1] = {args[0]};
75 
76   napi_value cons;
77   NODE_API_CALL(env, napi_get_reference_value(env, constructor, &cons));
78 
79   napi_value instance;
80   NODE_API_CALL(env, napi_new_instance(env, cons, argc, argv, &instance));
81 
82   return instance;
83 }
84 
GetValue(napi_env env, napi_callback_info info)85 napi_value MyObject::GetValue(napi_env env, napi_callback_info info) {
86   napi_value _this;
87   NODE_API_CALL(env,
88       napi_get_cb_info(env, info, nullptr, nullptr, &_this, nullptr));
89 
90   MyObject* obj;
91   NODE_API_CALL(env, napi_unwrap(env, _this, reinterpret_cast<void**>(&obj)));
92 
93   napi_value num;
94   NODE_API_CALL(env, napi_create_double(env, obj->value_, &num));
95 
96   return num;
97 }
98 
SetValue(napi_env env, napi_callback_info info)99 napi_value MyObject::SetValue(napi_env env, napi_callback_info info) {
100   size_t argc = 1;
101   napi_value args[1];
102   napi_value _this;
103   NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, &_this, nullptr));
104 
105   MyObject* obj;
106   NODE_API_CALL(env, napi_unwrap(env, _this, reinterpret_cast<void**>(&obj)));
107 
108   NODE_API_CALL(env, napi_get_value_double(env, args[0], &obj->value_));
109 
110   return nullptr;
111 }
112 
PlusOne(napi_env env, napi_callback_info info)113 napi_value MyObject::PlusOne(napi_env env, napi_callback_info info) {
114   napi_value _this;
115   NODE_API_CALL(env,
116       napi_get_cb_info(env, info, nullptr, nullptr, &_this, nullptr));
117 
118   MyObject* obj;
119   NODE_API_CALL(env, napi_unwrap(env, _this, reinterpret_cast<void**>(&obj)));
120 
121   obj->value_ += 1;
122 
123   napi_value num;
124   NODE_API_CALL(env, napi_create_double(env, obj->value_, &num));
125 
126   return num;
127 }
128 
Multiply(napi_env env, napi_callback_info info)129 napi_value MyObject::Multiply(napi_env env, napi_callback_info info) {
130   size_t argc = 1;
131   napi_value args[1];
132   napi_value _this;
133   NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, &_this, nullptr));
134 
135   double multiple = 1;
136   if (argc >= 1) {
137     NODE_API_CALL(env, napi_get_value_double(env, args[0], &multiple));
138   }
139 
140   MyObject* obj;
141   NODE_API_CALL(env, napi_unwrap(env, _this, reinterpret_cast<void**>(&obj)));
142 
143   napi_value cons;
144   NODE_API_CALL(env, napi_get_reference_value(env, constructor, &cons));
145 
146   const int kArgCount = 1;
147   napi_value argv[kArgCount];
148   NODE_API_CALL(env, napi_create_double(env, obj->value_ * multiple, argv));
149 
150   napi_value instance;
151   NODE_API_CALL(env, napi_new_instance(env, cons, kArgCount, argv, &instance));
152 
153   return instance;
154 }
155 
156 // This finalizer should never be invoked.
ObjectWrapDanglingReferenceFinalizer(napi_env env, void* finalize_data, void* finalize_hint)157 void ObjectWrapDanglingReferenceFinalizer(napi_env env,
158                                           void* finalize_data,
159                                           void* finalize_hint) {
160   assert(0 && "unreachable");
161 }
162 
163 napi_ref dangling_ref;
ObjectWrapDanglingReference(napi_env env, napi_callback_info info)164 napi_value ObjectWrapDanglingReference(napi_env env, napi_callback_info info) {
165   size_t argc = 1;
166   napi_value args[1];
167   NODE_API_CALL(env,
168                 napi_get_cb_info(env, info, &argc, args, nullptr, nullptr));
169 
170   // Create a napi_wrap and remove it immediately, whilst leaving the out-param
171   // ref dangling (not deleted).
172   NODE_API_CALL(env,
173                 napi_wrap(env,
174                           args[0],
175                           nullptr,
176                           ObjectWrapDanglingReferenceFinalizer,
177                           nullptr,
178                           &dangling_ref));
179   NODE_API_CALL(env, napi_remove_wrap(env, args[0], nullptr));
180 
181   return args[0];
182 }
183 
ObjectWrapDanglingReferenceTest(napi_env env, napi_callback_info info)184 napi_value ObjectWrapDanglingReferenceTest(napi_env env,
185                                            napi_callback_info info) {
186   napi_value out;
187   napi_value ret;
188   NODE_API_CALL(env, napi_get_reference_value(env, dangling_ref, &out));
189 
190   if (out == nullptr) {
191     // If the napi_ref has been invalidated, delete it.
192     NODE_API_CALL(env, napi_delete_reference(env, dangling_ref));
193     NODE_API_CALL(env, napi_get_boolean(env, true, &ret));
194   } else {
195     // The dangling napi_ref is still valid.
196     NODE_API_CALL(env, napi_get_boolean(env, false, &ret));
197   }
198   return ret;
199 }
200 
201 EXTERN_C_START
Init(napi_env env, napi_value exports)202 napi_value Init(napi_env env, napi_value exports) {
203   MyObject::Init(env, exports);
204 
205   napi_property_descriptor descriptors[] = {
206       DECLARE_NODE_API_PROPERTY("objectWrapDanglingReference",
207                                 ObjectWrapDanglingReference),
208       DECLARE_NODE_API_PROPERTY("objectWrapDanglingReferenceTest",
209                                 ObjectWrapDanglingReferenceTest),
210   };
211 
212   NODE_API_CALL(
213       env,
214       napi_define_properties(env,
215                              exports,
216                              sizeof(descriptors) / sizeof(*descriptors),
217                              descriptors));
218 
219   return exports;
220 }
221 EXTERN_C_END
222