You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

92 lines
2.2 KiB

#ifndef object_wrap_h
#define object_wrap_h
#include <v8.h>
#include <assert.h>
namespace node {
class ObjectWrap {
public:
ObjectWrap ( ) {
attached_ = 0;
}
virtual ~ObjectWrap ( ) {
if (!handle_.IsEmpty()) {
assert(handle_.IsNearDeath());
handle_->SetInternalField(0, v8::Undefined());
handle_.Dispose();
handle_.Clear();
}
}
protected:
template <class T>
static inline T* Unwrap (v8::Handle<v8::Object> handle)
{
assert(!handle.IsEmpty());
assert(handle->InternalFieldCount() > 0);
return static_cast<T*>(v8::Handle<v8::External>::Cast(
handle->GetInternalField(0))->Value());
}
inline void Wrap (v8::Handle<v8::Object> handle)
{
assert(handle_.IsEmpty());
assert(handle->InternalFieldCount() > 0);
handle_ = v8::Persistent<v8::Object>::New(handle);
handle_->SetInternalField(0, v8::External::New(this));
MakeWeak();
}
inline void MakeWeak (void)
{
handle_.MakeWeak(this, WeakCallback);
}
/* Attach() marks the object as being attached to an event loop.
* Attached objects will not be garbage collected, even if
* all references are lost.
*/
virtual void Attach() {
assert(!handle_.IsEmpty());
assert(handle_.IsWeak());
attached_++;
}
/* Detach() marks an object as detached from the event loop. This is its
* default state. When an object with a "weak" reference changes from
* attached to detached state it will be freed. Be careful not to access
* the object after making this call as it might be gone!
* (A "weak reference" is v8 terminology for an object that only has a
* persistant handle.)
*
* DO NOT CALL THIS FROM DESTRUCTOR
*/
virtual void Detach() {
assert(!handle_.IsEmpty());
assert(handle_.IsWeak());
assert(attached_ > 0);
attached_--;
if (attached_ == 0 && handle_.IsNearDeath()) delete this;
}
v8::Persistent<v8::Object> handle_; // ro
int attached_; // ro
private:
static void WeakCallback (v8::Persistent<v8::Value> value, void *data)
{
ObjectWrap *obj = static_cast<ObjectWrap*>(data);
assert(value == obj->handle_);
if (obj->attached_ == 0) {
delete obj;
} else {
obj->MakeWeak();
}
}
};
} // namespace node
#endif // object_wrap_h