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
|
#ifndef SRC_NODE_PERSISTENT_H_
#define SRC_NODE_PERSISTENT_H_
#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
#include "v8.h"
namespace node {
template <typename T>
struct ResetInDestructorPersistentTraits {
static const bool kResetInDestructor = true;
template <typename S, typename M>
// Disallow copy semantics by leaving this unimplemented.
inline static void Copy(
const v8::Persistent<S, M>&,
v8::Persistent<T, ResetInDestructorPersistentTraits<T>>*);
};
// v8::Persistent does not reset the object slot in its destructor. That is
// acknowledged as a flaw in the V8 API and expected to change in the future
// but for now node::Persistent is the easier and safer alternative.
template <typename T>
using Persistent = v8::Persistent<T, ResetInDestructorPersistentTraits<T>>;
class PersistentToLocal {
public:
// If persistent.IsWeak() == false, then do not call persistent.Reset()
// while the returned Local<T> is still in scope, it will destroy the
// reference to the object.
template <class TypeName>
static inline v8::Local<TypeName> Default(
v8::Isolate* isolate,
const Persistent<TypeName>& persistent) {
if (persistent.IsWeak()) {
return PersistentToLocal::Weak(isolate, persistent);
} else {
return PersistentToLocal::Strong(persistent);
}
}
// Unchecked conversion from a non-weak Persistent<T> to Local<T>,
// use with care!
//
// Do not call persistent.Reset() while the returned Local<T> is still in
// scope, it will destroy the reference to the object.
template <class TypeName>
static inline v8::Local<TypeName> Strong(
const Persistent<TypeName>& persistent) {
return *reinterpret_cast<v8::Local<TypeName>*>(
const_cast<Persistent<TypeName>*>(&persistent));
}
template <class TypeName>
static inline v8::Local<TypeName> Weak(
v8::Isolate* isolate,
const Persistent<TypeName>& persistent) {
return v8::Local<TypeName>::New(isolate, persistent);
}
};
} // namespace node
#endif // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
#endif // SRC_NODE_PERSISTENT_H_
|
