forked from nodejs/node
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathjs_native_api_v8.cc
More file actions
3565 lines (2922 loc) · 123 KB
/
js_native_api_v8.cc
File metadata and controls
3565 lines (2922 loc) · 123 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#include <algorithm>
#include <climits> // INT_MAX
#include <cmath>
#define NAPI_EXPERIMENTAL
#include "env-inl.h"
#include "js_native_api.h"
#include "js_native_api_v8.h"
#include "util-inl.h"
#define CHECK_MAYBE_NOTHING(env, maybe, status) \
RETURN_STATUS_IF_FALSE((env), !((maybe).IsNothing()), (status))
#define CHECK_MAYBE_NOTHING_WITH_PREAMBLE(env, maybe, status) \
RETURN_STATUS_IF_FALSE_WITH_PREAMBLE((env), !((maybe).IsNothing()), (status))
#define CHECK_TO_NUMBER(env, context, result, src) \
CHECK_TO_TYPE((env), Number, (context), (result), (src), napi_number_expected)
// n-api defines NAPI_AUTO_LENGTH as the indicator that a string
// is null terminated. For V8 the equivalent is -1. The assert
// validates that our cast of NAPI_AUTO_LENGTH results in -1 as
// needed by V8.
#define CHECK_NEW_FROM_UTF8_LEN(env, result, str, len) \
do { \
static_assert(static_cast<int>(NAPI_AUTO_LENGTH) == -1, \
"Casting NAPI_AUTO_LENGTH to int must result in -1"); \
RETURN_STATUS_IF_FALSE( \
(env), (len == NAPI_AUTO_LENGTH) || len <= INT_MAX, napi_invalid_arg); \
RETURN_STATUS_IF_FALSE((env), (str) != nullptr, napi_invalid_arg); \
auto str_maybe = v8::String::NewFromUtf8((env)->isolate, \
(str), \
v8::NewStringType::kInternalized, \
static_cast<int>(len)); \
CHECK_MAYBE_EMPTY((env), str_maybe, napi_generic_failure); \
(result) = str_maybe.ToLocalChecked(); \
} while (0)
#define CHECK_NEW_FROM_UTF8(env, result, str) \
CHECK_NEW_FROM_UTF8_LEN((env), (result), (str), NAPI_AUTO_LENGTH)
#define CHECK_NEW_STRING_ARGS(env, str, length, result) \
do { \
CHECK_ENV_NOT_IN_GC((env)); \
if ((length) > 0) CHECK_ARG((env), (str)); \
CHECK_ARG((env), (result)); \
RETURN_STATUS_IF_FALSE( \
(env), \
((length) == NAPI_AUTO_LENGTH) || (length) <= INT_MAX, \
napi_invalid_arg); \
} while (0)
#define CREATE_TYPED_ARRAY( \
env, type, size_of_element, buffer, byte_offset, length, out) \
do { \
if ((size_of_element) > 1) { \
THROW_RANGE_ERROR_IF_FALSE( \
(env), \
(byte_offset) % (size_of_element) == 0, \
"ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT", \
"start offset of " #type \
" should be a multiple of " #size_of_element); \
} \
THROW_RANGE_ERROR_IF_FALSE( \
(env), \
(length) * (size_of_element) + (byte_offset) <= buffer->ByteLength(), \
"ERR_NAPI_INVALID_TYPEDARRAY_LENGTH", \
"Invalid typed array length"); \
(out) = v8::type::New((buffer), (byte_offset), (length)); \
} while (0)
void napi_env__::InvokeFinalizerFromGC(v8impl::RefTracker* finalizer) {
if (module_api_version != NAPI_VERSION_EXPERIMENTAL) {
EnqueueFinalizer(finalizer);
} else {
// The experimental code calls finalizers immediately to release native
// objects as soon as possible. In that state any code that may affect GC
// state causes a fatal error. To work around this issue the finalizer code
// can call node_api_post_finalizer.
auto restore_state = node::OnScopeLeave(
[this, saved = in_gc_finalizer] { in_gc_finalizer = saved; });
in_gc_finalizer = true;
finalizer->Finalize();
}
}
namespace v8impl {
namespace {
template <typename CCharType, typename StringMaker>
napi_status NewString(napi_env env,
const CCharType* str,
size_t length,
napi_value* result,
StringMaker string_maker) {
CHECK_NEW_STRING_ARGS(env, str, length, result);
auto isolate = env->isolate;
auto str_maybe = string_maker(isolate);
CHECK_MAYBE_EMPTY(env, str_maybe, napi_generic_failure);
*result = v8impl::JsValueFromV8LocalValue(str_maybe.ToLocalChecked());
return napi_clear_last_error(env);
}
template <typename CharType, typename CreateAPI, typename StringMaker>
napi_status NewExternalString(napi_env env,
CharType* str,
size_t length,
napi_finalize finalize_callback,
void* finalize_hint,
napi_value* result,
bool* copied,
CreateAPI create_api,
StringMaker string_maker) {
CHECK_NEW_STRING_ARGS(env, str, length, result);
napi_status status;
#ifdef V8_ENABLE_SANDBOX
status = create_api(env, str, length, result);
if (status == napi_ok) {
if (copied != nullptr) {
*copied = true;
}
if (finalize_callback) {
env->CallFinalizer(
finalize_callback, static_cast<CharType*>(str), finalize_hint);
}
}
#else
status = NewString(env, str, length, result, string_maker);
if (status == napi_ok && copied != nullptr) {
*copied = false;
}
#endif // V8_ENABLE_SANDBOX
return status;
}
class TrackedStringResource : private RefTracker {
public:
TrackedStringResource(napi_env env,
napi_finalize finalize_callback,
void* data,
void* finalize_hint)
: RefTracker(), finalizer_(env, finalize_callback, data, finalize_hint) {
Link(finalize_callback == nullptr ? &env->reflist
: &env->finalizing_reflist);
}
protected:
// The only time Finalize() gets called before destructor is if the
// environment is dying. Finalize() expects that the item will be unlinked,
// so we do it here. V8 will still call destructor on us later, so we don't do
// any deleting here. We just null out env to avoid passing a stale pointer
// to the user's finalizer when V8 does finally call destructor.
void Finalize() override {
Unlink();
finalizer_.ResetEnv();
}
~TrackedStringResource() override {
Unlink();
finalizer_.CallFinalizer();
}
private:
Finalizer finalizer_;
};
class ExternalOneByteStringResource final
: public v8::String::ExternalOneByteStringResource,
TrackedStringResource {
public:
ExternalOneByteStringResource(napi_env env,
char* string,
const size_t length,
napi_finalize finalize_callback,
void* finalize_hint)
: TrackedStringResource(env, finalize_callback, string, finalize_hint),
string_(string),
length_(length) {}
const char* data() const override { return string_; }
size_t length() const override { return length_; }
private:
const char* string_;
const size_t length_;
};
class ExternalStringResource final : public v8::String::ExternalStringResource,
TrackedStringResource {
public:
ExternalStringResource(napi_env env,
char16_t* string,
const size_t length,
napi_finalize finalize_callback,
void* finalize_hint)
: TrackedStringResource(env, finalize_callback, string, finalize_hint),
string_(reinterpret_cast<uint16_t*>(string)),
length_(length) {}
const uint16_t* data() const override { return string_; }
size_t length() const override { return length_; }
private:
const uint16_t* string_;
const size_t length_;
};
inline napi_status V8NameFromPropertyDescriptor(
napi_env env,
const napi_property_descriptor* p,
v8::Local<v8::Name>* result) {
if (p->utf8name != nullptr) {
CHECK_NEW_FROM_UTF8(env, *result, p->utf8name);
} else {
v8::Local<v8::Value> property_value =
v8impl::V8LocalValueFromJsValue(p->name);
RETURN_STATUS_IF_FALSE(env, property_value->IsName(), napi_name_expected);
*result = property_value.As<v8::Name>();
}
return napi_ok;
}
// convert from n-api property attributes to v8::PropertyAttribute
inline v8::PropertyAttribute V8PropertyAttributesFromDescriptor(
const napi_property_descriptor* descriptor) {
unsigned int attribute_flags = v8::PropertyAttribute::None;
// The napi_writable attribute is ignored for accessor descriptors, but
// V8 would throw `TypeError`s on assignment with nonexistence of a setter.
if ((descriptor->getter == nullptr && descriptor->setter == nullptr) &&
(descriptor->attributes & napi_writable) == 0) {
attribute_flags |= v8::PropertyAttribute::ReadOnly;
}
if ((descriptor->attributes & napi_enumerable) == 0) {
attribute_flags |= v8::PropertyAttribute::DontEnum;
}
if ((descriptor->attributes & napi_configurable) == 0) {
attribute_flags |= v8::PropertyAttribute::DontDelete;
}
return static_cast<v8::PropertyAttribute>(attribute_flags);
}
inline napi_deferred JsDeferredFromNodePersistent(
v8impl::Persistent<v8::Value>* local) {
return reinterpret_cast<napi_deferred>(local);
}
inline v8impl::Persistent<v8::Value>* NodePersistentFromJsDeferred(
napi_deferred local) {
return reinterpret_cast<v8impl::Persistent<v8::Value>*>(local);
}
class HandleScopeWrapper {
public:
explicit HandleScopeWrapper(v8::Isolate* isolate) : scope(isolate) {}
private:
v8::HandleScope scope;
};
// In node v0.10 version of v8, there is no EscapableHandleScope and the
// node v0.10 port use HandleScope::Close(Local<T> v) to mimic the behavior
// of a EscapableHandleScope::Escape(Local<T> v), but it is not the same
// semantics. This is an example of where the api abstraction fail to work
// across different versions.
class EscapableHandleScopeWrapper {
public:
explicit EscapableHandleScopeWrapper(v8::Isolate* isolate)
: scope(isolate), escape_called_(false) {}
bool escape_called() const { return escape_called_; }
template <typename T>
v8::Local<T> Escape(v8::Local<T> handle) {
escape_called_ = true;
return scope.Escape(handle);
}
private:
v8::EscapableHandleScope scope;
bool escape_called_;
};
inline napi_handle_scope JsHandleScopeFromV8HandleScope(HandleScopeWrapper* s) {
return reinterpret_cast<napi_handle_scope>(s);
}
inline HandleScopeWrapper* V8HandleScopeFromJsHandleScope(napi_handle_scope s) {
return reinterpret_cast<HandleScopeWrapper*>(s);
}
inline napi_escapable_handle_scope
JsEscapableHandleScopeFromV8EscapableHandleScope(
EscapableHandleScopeWrapper* s) {
return reinterpret_cast<napi_escapable_handle_scope>(s);
}
inline EscapableHandleScopeWrapper*
V8EscapableHandleScopeFromJsEscapableHandleScope(
napi_escapable_handle_scope s) {
return reinterpret_cast<EscapableHandleScopeWrapper*>(s);
}
inline napi_status ConcludeDeferred(napi_env env,
napi_deferred deferred,
napi_value result,
bool is_resolved) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, result);
v8::Local<v8::Context> context = env->context();
v8impl::Persistent<v8::Value>* deferred_ref =
NodePersistentFromJsDeferred(deferred);
v8::Local<v8::Value> v8_deferred =
v8::Local<v8::Value>::New(env->isolate, *deferred_ref);
auto v8_resolver = v8_deferred.As<v8::Promise::Resolver>();
v8::Maybe<bool> success =
is_resolved ? v8_resolver->Resolve(
context, v8impl::V8LocalValueFromJsValue(result))
: v8_resolver->Reject(
context, v8impl::V8LocalValueFromJsValue(result));
delete deferred_ref;
RETURN_STATUS_IF_FALSE(env, success.FromMaybe(false), napi_generic_failure);
return GET_RETURN_STATUS(env);
}
enum UnwrapAction { KeepWrap, RemoveWrap };
inline napi_status Unwrap(napi_env env,
napi_value js_object,
void** result,
UnwrapAction action) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, js_object);
if (action == KeepWrap) {
CHECK_ARG(env, result);
}
v8::Local<v8::Context> context = env->context();
v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(js_object);
RETURN_STATUS_IF_FALSE(env, value->IsObject(), napi_invalid_arg);
v8::Local<v8::Object> obj = value.As<v8::Object>();
auto val = obj->GetPrivate(context, NAPI_PRIVATE_KEY(context, wrapper))
.ToLocalChecked();
RETURN_STATUS_IF_FALSE(env, val->IsExternal(), napi_invalid_arg);
Reference* reference =
static_cast<v8impl::Reference*>(val.As<v8::External>()->Value());
if (result) {
*result = reference->Data();
}
if (action == RemoveWrap) {
CHECK(obj->DeletePrivate(context, NAPI_PRIVATE_KEY(context, wrapper))
.FromJust());
if (reference->ownership() == ReferenceOwnership::kUserland) {
// When the wrap is been removed, the finalizer should be reset.
reference->ResetFinalizer();
} else {
delete reference;
}
}
return GET_RETURN_STATUS(env);
}
//=== Function napi_callback wrapper =================================
// Use this data structure to associate callback data with each N-API function
// exposed to JavaScript. The structure is stored in a v8::External which gets
// passed into our callback wrapper. This reduces the performance impact of
// calling through N-API.
// Ref: benchmark/misc/function_call
// Discussion (incl. perf. data): https://github.com/nodejs/node/pull/21072
class CallbackBundle {
public:
// Creates an object to be made available to the static function callback
// wrapper, used to retrieve the native callback function and data pointer.
static inline v8::Local<v8::Value> New(napi_env env,
napi_callback cb,
void* data) {
CallbackBundle* bundle = new CallbackBundle();
bundle->cb = cb;
bundle->cb_data = data;
bundle->env = env;
v8::Local<v8::Value> cbdata = v8::External::New(env->isolate, bundle);
ReferenceWithFinalizer::New(
env, cbdata, 0, ReferenceOwnership::kRuntime, Delete, bundle, nullptr);
return cbdata;
}
static CallbackBundle* FromCallbackData(v8::Local<v8::Value> data) {
return reinterpret_cast<CallbackBundle*>(data.As<v8::External>()->Value());
}
public:
napi_env env; // Necessary to invoke C++ NAPI callback
void* cb_data; // The user provided callback data
napi_callback cb;
private:
static void Delete(napi_env env, void* data, void* hint) {
CallbackBundle* bundle = static_cast<CallbackBundle*>(data);
delete bundle;
}
};
// Wraps up v8::FunctionCallbackInfo.
// The class must be stack allocated.
class FunctionCallbackWrapper {
public:
static void Invoke(const v8::FunctionCallbackInfo<v8::Value>& info) {
FunctionCallbackWrapper cbwrapper(info);
cbwrapper.InvokeCallback();
}
static inline napi_status NewFunction(napi_env env,
napi_callback cb,
void* cb_data,
v8::Local<v8::Function>* result) {
v8::Local<v8::Value> cbdata = v8impl::CallbackBundle::New(env, cb, cb_data);
RETURN_STATUS_IF_FALSE(env, !cbdata.IsEmpty(), napi_generic_failure);
v8::MaybeLocal<v8::Function> maybe_function =
v8::Function::New(env->context(), Invoke, cbdata);
CHECK_MAYBE_EMPTY(env, maybe_function, napi_generic_failure);
*result = maybe_function.ToLocalChecked();
return napi_clear_last_error(env);
}
static inline napi_status NewTemplate(
napi_env env,
napi_callback cb,
void* cb_data,
v8::Local<v8::FunctionTemplate>* result,
v8::Local<v8::Signature> sig = v8::Local<v8::Signature>()) {
v8::Local<v8::Value> cbdata = v8impl::CallbackBundle::New(env, cb, cb_data);
RETURN_STATUS_IF_FALSE(env, !cbdata.IsEmpty(), napi_generic_failure);
*result = v8::FunctionTemplate::New(env->isolate, Invoke, cbdata, sig);
return napi_clear_last_error(env);
}
napi_value GetNewTarget() {
if (cbinfo_.IsConstructCall()) {
return v8impl::JsValueFromV8LocalValue(cbinfo_.NewTarget());
} else {
return nullptr;
}
}
void Args(napi_value* buffer, size_t buffer_length) {
size_t i = 0;
size_t min_arg_count = std::min(buffer_length, ArgsLength());
for (; i < min_arg_count; ++i) {
buffer[i] = JsValueFromV8LocalValue(cbinfo_[i]);
}
if (i < buffer_length) {
napi_value undefined =
JsValueFromV8LocalValue(v8::Undefined(cbinfo_.GetIsolate()));
for (; i < buffer_length; ++i) {
buffer[i] = undefined;
}
}
}
napi_value This() { return JsValueFromV8LocalValue(cbinfo_.This()); }
size_t ArgsLength() { return static_cast<size_t>(cbinfo_.Length()); }
void* Data() { return bundle_->cb_data; }
private:
explicit FunctionCallbackWrapper(
const v8::FunctionCallbackInfo<v8::Value>& cbinfo)
: cbinfo_(cbinfo),
bundle_(CallbackBundle::FromCallbackData(cbinfo.Data())) {}
void InvokeCallback() {
napi_callback_info cbinfo_wrapper =
reinterpret_cast<napi_callback_info>(this);
// All other pointers we need are stored in `_bundle`
napi_env env = bundle_->env;
napi_callback cb = bundle_->cb;
napi_value result = nullptr;
bool exceptionOccurred = false;
env->CallIntoModule([&](napi_env env) { result = cb(env, cbinfo_wrapper); },
[&](napi_env env, v8::Local<v8::Value> value) {
exceptionOccurred = true;
if (env->terminatedOrTerminating()) {
return;
}
env->isolate->ThrowException(value);
});
if (!exceptionOccurred && (result != nullptr)) {
cbinfo_.GetReturnValue().Set(V8LocalValueFromJsValue(result));
}
}
private:
const v8::FunctionCallbackInfo<v8::Value>& cbinfo_;
CallbackBundle* bundle_;
};
inline napi_status Wrap(napi_env env,
napi_value js_object,
void* native_object,
napi_finalize finalize_cb,
void* finalize_hint,
napi_ref* result) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, js_object);
v8::Local<v8::Context> context = env->context();
v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(js_object);
RETURN_STATUS_IF_FALSE(env, value->IsObject(), napi_invalid_arg);
v8::Local<v8::Object> obj = value.As<v8::Object>();
// If we've already wrapped this object, we error out.
RETURN_STATUS_IF_FALSE(
env,
!obj->HasPrivate(context, NAPI_PRIVATE_KEY(context, wrapper)).FromJust(),
napi_invalid_arg);
v8impl::Reference* reference = nullptr;
if (result != nullptr) {
// The returned reference should be deleted via napi_delete_reference()
// ONLY in response to the finalize callback invocation. (If it is deleted
// before then, then the finalize callback will never be invoked.)
// Therefore a finalize callback is required when returning a reference.
CHECK_ARG(env, finalize_cb);
reference = v8impl::ReferenceWithFinalizer::New(
env,
obj,
0,
v8impl::ReferenceOwnership::kUserland,
finalize_cb,
native_object,
finalize_hint);
*result = reinterpret_cast<napi_ref>(reference);
} else if (finalize_cb != nullptr) {
// Create a self-deleting reference.
reference = v8impl::ReferenceWithFinalizer::New(
env,
obj,
0,
v8impl::ReferenceOwnership::kRuntime,
finalize_cb,
native_object,
finalize_hint);
} else {
// Create a self-deleting reference.
reference = v8impl::ReferenceWithData::New(
env, obj, 0, v8impl::ReferenceOwnership::kRuntime, native_object);
}
CHECK(obj->SetPrivate(context,
NAPI_PRIVATE_KEY(context, wrapper),
v8::External::New(env->isolate, reference))
.FromJust());
return GET_RETURN_STATUS(env);
}
// In JavaScript, weak references can be created for object types (Object,
// Function, and external Object) and for local symbols that are created with
// the `Symbol` function call. Global symbols created with the `Symbol.for`
// method cannot be weak references because they are never collected.
//
// Currently, V8 has no API to detect if a symbol is local or global.
// Until we have a V8 API for it, we consider that all symbols can be weak.
// This matches the current Node-API behavior.
inline bool CanBeHeldWeakly(v8::Local<v8::Value> value) {
return value->IsObject() || value->IsSymbol();
}
} // end of anonymous namespace
void Finalizer::ResetEnv() {
env_ = nullptr;
}
void Finalizer::ResetFinalizer() {
finalize_callback_ = nullptr;
finalize_data_ = nullptr;
finalize_hint_ = nullptr;
}
void Finalizer::CallFinalizer() {
napi_finalize finalize_callback = finalize_callback_;
void* finalize_data = finalize_data_;
void* finalize_hint = finalize_hint_;
ResetFinalizer();
if (finalize_callback == nullptr) return;
if (env_ == nullptr) {
// The environment is dead. Call the finalizer directly.
finalize_callback(nullptr, finalize_data, finalize_hint);
} else {
env_->CallFinalizer(finalize_callback, finalize_data, finalize_hint);
}
}
TrackedFinalizer::TrackedFinalizer(napi_env env,
napi_finalize finalize_callback,
void* finalize_data,
void* finalize_hint)
: RefTracker(),
finalizer_(env, finalize_callback, finalize_data, finalize_hint) {}
TrackedFinalizer* TrackedFinalizer::New(napi_env env,
napi_finalize finalize_callback,
void* finalize_data,
void* finalize_hint) {
TrackedFinalizer* finalizer = new TrackedFinalizer(
env, finalize_callback, finalize_data, finalize_hint);
finalizer->Link(&env->finalizing_reflist);
return finalizer;
}
// When a TrackedFinalizer is being deleted, it may have been queued to call its
// finalizer.
TrackedFinalizer::~TrackedFinalizer() {
// Remove from the env's tracked list.
Unlink();
// Try to remove the finalizer from the scheduled second pass callback.
finalizer_.env()->DequeueFinalizer(this);
}
void TrackedFinalizer::Finalize() {
Unlink();
finalizer_.CallFinalizer();
delete this;
}
Reference::Reference(napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership)
: RefTracker(),
persistent_(env->isolate, value),
refcount_(initial_refcount),
ownership_(ownership),
can_be_weak_(CanBeHeldWeakly(value)) {
if (refcount_ == 0) {
SetWeak();
}
}
Reference::~Reference() {
// Reset the handle. And no weak callback will be invoked.
persistent_.Reset();
// Remove from the env's tracked list.
Unlink();
}
Reference* Reference::New(napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership) {
Reference* reference = new Reference(env, value, initial_refcount, ownership);
reference->Link(&env->reflist);
return reference;
}
uint32_t Reference::Ref() {
// When the persistent_ is cleared in the WeakCallback, and a second pass
// callback is pending, return 0 unconditionally.
if (persistent_.IsEmpty()) {
return 0;
}
if (++refcount_ == 1 && can_be_weak_) {
persistent_.ClearWeak();
}
return refcount_;
}
uint32_t Reference::Unref() {
// When the persistent_ is cleared in the WeakCallback, and a second pass
// callback is pending, return 0 unconditionally.
if (persistent_.IsEmpty() || refcount_ == 0) {
return 0;
}
if (--refcount_ == 0) {
SetWeak();
}
return refcount_;
}
v8::Local<v8::Value> Reference::Get(napi_env env) {
if (persistent_.IsEmpty()) {
return v8::Local<v8::Value>();
} else {
return v8::Local<v8::Value>::New(env->isolate, persistent_);
}
}
void Reference::Finalize() {
// Unconditionally reset the persistent handle so that no weak callback will
// be invoked again.
persistent_.Reset();
// If the Reference is not ReferenceOwnership::kRuntime, userland code should
// delete it. Delete it if it is ReferenceOwnership::kRuntime.
bool deleteMe = ownership_ == ReferenceOwnership::kRuntime;
// Whether the Reference is going to be deleted in the finalize_callback
// or not, it should be removed from the tracked list.
Unlink();
// If the finalize_callback is present, it should either delete the
// derived Reference, or the Reference ownership was set to
// ReferenceOwnership::kRuntime and the deleteMe parameter is true.
CallUserFinalizer();
if (deleteMe) {
delete this;
}
}
// Call the Finalize immediately since there is no user finalizer to call.
void Reference::InvokeFinalizerFromGC() {
Finalize();
}
// Mark the reference as weak and eligible for collection by the GC.
void Reference::SetWeak() {
if (can_be_weak_) {
persistent_.SetWeak(this, WeakCallback, v8::WeakCallbackType::kParameter);
} else {
persistent_.Reset();
}
}
// Static function called by GC. Delegate the call to the reference instance.
void Reference::WeakCallback(const v8::WeakCallbackInfo<Reference>& data) {
Reference* reference = data.GetParameter();
// The reference must be reset during the weak callback per V8 API protocol.
reference->persistent_.Reset();
reference->InvokeFinalizerFromGC();
}
ReferenceWithData* ReferenceWithData::New(napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership,
void* data) {
ReferenceWithData* reference =
new ReferenceWithData(env, value, initial_refcount, ownership, data);
reference->Link(&env->reflist);
return reference;
}
ReferenceWithData::ReferenceWithData(napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership,
void* data)
: Reference(env, value, initial_refcount, ownership), data_(data) {}
ReferenceWithFinalizer* ReferenceWithFinalizer::New(
napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership,
napi_finalize finalize_callback,
void* finalize_data,
void* finalize_hint) {
ReferenceWithFinalizer* reference =
new ReferenceWithFinalizer(env,
value,
initial_refcount,
ownership,
finalize_callback,
finalize_data,
finalize_hint);
reference->Link(&env->finalizing_reflist);
return reference;
}
ReferenceWithFinalizer::ReferenceWithFinalizer(napi_env env,
v8::Local<v8::Value> value,
uint32_t initial_refcount,
ReferenceOwnership ownership,
napi_finalize finalize_callback,
void* finalize_data,
void* finalize_hint)
: Reference(env, value, initial_refcount, ownership),
finalizer_(env, finalize_callback, finalize_data, finalize_hint) {}
ReferenceWithFinalizer::~ReferenceWithFinalizer() {
// Try to remove the finalizer from the scheduled second pass callback.
finalizer_.env()->DequeueFinalizer(this);
}
void ReferenceWithFinalizer::CallUserFinalizer() {
finalizer_.CallFinalizer();
}
// The Node-API finalizer callback may make calls into the engine. V8's heap is
// not in a consistent state during the weak callback, and therefore it does
// not support calls back into it. Enqueue the invocation of the finalizer.
void ReferenceWithFinalizer::InvokeFinalizerFromGC() {
finalizer_.env()->InvokeFinalizerFromGC(this);
}
/**
* A wrapper for `v8::External` to support type-tagging. `v8::External` doesn't
* support defining any properties and private properties on it, even though it
* is an object. This wrapper is used to store the type tag and the data of the
* external value.
*/
class ExternalWrapper {
private:
explicit ExternalWrapper(void* data) : data_(data), type_tag_{0, 0} {}
static void WeakCallback(const v8::WeakCallbackInfo<ExternalWrapper>& data) {
ExternalWrapper* wrapper = data.GetParameter();
delete wrapper;
}
public:
static v8::Local<v8::External> New(napi_env env, void* data) {
ExternalWrapper* wrapper = new ExternalWrapper(data);
v8::Local<v8::External> external = v8::External::New(env->isolate, wrapper);
wrapper->persistent_.Reset(env->isolate, external);
wrapper->persistent_.SetWeak(
wrapper, WeakCallback, v8::WeakCallbackType::kParameter);
return external;
}
static ExternalWrapper* From(v8::Local<v8::External> external) {
return static_cast<ExternalWrapper*>(external->Value());
}
void* Data() { return data_; }
bool TypeTag(const napi_type_tag* type_tag) {
if (has_tag_) {
return false;
}
type_tag_ = *type_tag;
has_tag_ = true;
return true;
}
bool CheckTypeTag(const napi_type_tag* type_tag) {
return has_tag_ && type_tag->lower == type_tag_.lower &&
type_tag->upper == type_tag_.upper;
}
private:
v8impl::Persistent<v8::Value> persistent_;
void* data_;
napi_type_tag type_tag_;
bool has_tag_ = false;
};
} // end of namespace v8impl
// Warning: Keep in-sync with napi_status enum
static const char* error_messages[] = {
nullptr,
"Invalid argument",
"An object was expected",
"A string was expected",
"A string or symbol was expected",
"A function was expected",
"A number was expected",
"A boolean was expected",
"An array was expected",
"Unknown failure",
"An exception is pending",
"The async work item was cancelled",
"napi_escape_handle already called on scope",
"Invalid handle scope usage",
"Invalid callback scope usage",
"Thread-safe function queue is full",
"Thread-safe function handle is closing",
"A bigint was expected",
"A date was expected",
"An arraybuffer was expected",
"A detachable arraybuffer was expected",
"Main thread would deadlock",
"External buffers are not allowed",
"Cannot run JavaScript",
};
napi_status NAPI_CDECL napi_get_last_error_info(
node_api_basic_env basic_env, const napi_extended_error_info** result) {
napi_env env = const_cast<napi_env>(basic_env);
CHECK_ENV(env);
CHECK_ARG(env, result);
// The value of the constant below must be updated to reference the last
// message in the `napi_status` enum each time a new error message is added.
// We don't have a napi_status_last as this would result in an ABI
// change each time a message was added.
const int last_status = napi_cannot_run_js;
static_assert(NAPI_ARRAYSIZE(error_messages) == last_status + 1,
"Count of error messages must match count of error values");
CHECK_LE(env->last_error.error_code, last_status);
// Wait until someone requests the last error information to fetch the error
// message string
env->last_error.error_message = error_messages[env->last_error.error_code];
if (env->last_error.error_code == napi_ok) {
napi_clear_last_error(env);
}
*result = &(env->last_error);
return napi_ok;
}
napi_status NAPI_CDECL napi_create_function(napi_env env,
const char* utf8name,
size_t length,
napi_callback cb,
void* callback_data,
napi_value* result) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, result);
CHECK_ARG(env, cb);
v8::Local<v8::Function> return_value;
v8::EscapableHandleScope scope(env->isolate);
v8::Local<v8::Function> fn;
STATUS_CALL(v8impl::FunctionCallbackWrapper::NewFunction(
env, cb, callback_data, &fn));
return_value = scope.Escape(fn);
if (utf8name != nullptr) {
v8::Local<v8::String> name_string;
CHECK_NEW_FROM_UTF8_LEN(env, name_string, utf8name, length);
return_value->SetName(name_string);
}
*result = v8impl::JsValueFromV8LocalValue(return_value);
return GET_RETURN_STATUS(env);
}
napi_status NAPI_CDECL
napi_define_class(napi_env env,
const char* utf8name,
size_t length,
napi_callback constructor,
void* callback_data,
size_t property_count,
const napi_property_descriptor* properties,
napi_value* result) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, result);
CHECK_ARG(env, constructor);
if (property_count > 0) {
CHECK_ARG(env, properties);
}
v8::Isolate* isolate = env->isolate;
v8::EscapableHandleScope scope(isolate);
v8::Local<v8::FunctionTemplate> tpl;
STATUS_CALL(v8impl::FunctionCallbackWrapper::NewTemplate(
env, constructor, callback_data, &tpl));
v8::Local<v8::String> name_string;
CHECK_NEW_FROM_UTF8_LEN(env, name_string, utf8name, length);
tpl->SetClassName(name_string);
size_t static_property_count = 0;
for (size_t i = 0; i < property_count; i++) {
const napi_property_descriptor* p = properties + i;
if ((p->attributes & napi_static) != 0) {
// Static properties are handled separately below.
static_property_count++;
continue;
}