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1/*********************************************************************
2 * NAN - Native Abstractions for Node.js
3 *
4 * Copyright (c) 2018 NAN contributors
5 *
6 * MIT License <https://github.com/nodejs/nan/blob/master/LICENSE.md>
7 ********************************************************************/
8
9#ifndef NAN_TYPEDARRAY_CONTENTS_H_
10#define NAN_TYPEDARRAY_CONTENTS_H_
11
12template<typename T>
13class TypedArrayContents {
14 public:
15 inline explicit TypedArrayContents(v8::Local<v8::Value> from) :
16 length_(0), data_(NULL) {
17 HandleScope scope;
18
19 size_t length = 0;
20 void* data = NULL;
21
22#if defined(V8_MAJOR_VERSION) && (V8_MAJOR_VERSION > 4 || \
23 (V8_MAJOR_VERSION == 4 && defined(V8_MINOR_VERSION) && V8_MINOR_VERSION >= 3))
24
25 if (from->IsArrayBufferView()) {
26 v8::Local<v8::ArrayBufferView> array =
27 v8::Local<v8::ArrayBufferView>::Cast(from);
28
29 const size_t byte_length = array->ByteLength();
30 const ptrdiff_t byte_offset = array->ByteOffset();
31 v8::Local<v8::ArrayBuffer> buffer = array->Buffer();
32
33 length = byte_length / sizeof(T);
34// Actually it's 7.9 here but this would lead to ABI issues with Node.js 13
35// using 7.8 till 13.2.0.
36#if (V8_MAJOR_VERSION >= 8)
37 data = static_cast<char*>(buffer->GetBackingStore()->Data()) + byte_offset;
38#else
39 data = static_cast<char*>(buffer->GetContents().Data()) + byte_offset;
40#endif
41 }
42
43#else
44
45 if (from->IsObject() && !from->IsNull()) {
46 v8::Local<v8::Object> array = v8::Local<v8::Object>::Cast(from);
47
48 MaybeLocal<v8::Value> buffer = Get(array,
49 New<v8::String>("buffer").ToLocalChecked());
50 MaybeLocal<v8::Value> byte_length = Get(array,
51 New<v8::String>("byteLength").ToLocalChecked());
52 MaybeLocal<v8::Value> byte_offset = Get(array,
53 New<v8::String>("byteOffset").ToLocalChecked());
54
55 if (!buffer.IsEmpty() &&
56 !byte_length.IsEmpty() && byte_length.ToLocalChecked()->IsUint32() &&
57 !byte_offset.IsEmpty() && byte_offset.ToLocalChecked()->IsUint32()) {
58 data = array->GetIndexedPropertiesExternalArrayData();
59 if(data) {
60 length = byte_length.ToLocalChecked()->Uint32Value() / sizeof(T);
61 }
62 }
63 }
64
65#endif
66
67#if defined(_MSC_VER) && _MSC_VER >= 1900 || __cplusplus >= 201103L
68 assert(reinterpret_cast<uintptr_t>(data) % alignof (T) == 0);
69#elif defined(_MSC_VER) && _MSC_VER >= 1600 || defined(__GNUC__)
70 assert(reinterpret_cast<uintptr_t>(data) % __alignof(T) == 0);
71#else
72 assert(reinterpret_cast<uintptr_t>(data) % sizeof (T) == 0);
73#endif
74
75 length_ = length;
76 data_ = static_cast<T*>(data);
77 }
78
79 inline size_t length() const { return length_; }
80 inline T* operator*() { return data_; }
81 inline const T* operator*() const { return data_; }
82
83 private:
84 NAN_DISALLOW_ASSIGN_COPY_MOVE(TypedArrayContents)
85
86 //Disable heap allocation
87 void *operator new(size_t size);
88 void operator delete(void *, size_t) {
89 abort();
90 }
91
92 size_t length_;
93 T* data_;
94};
95
96#endif // NAN_TYPEDARRAY_CONTENTS_H_