electron/native_mate/scoped_persistent.h
2014-04-18 16:45:44 +08:00

111 lines
2.7 KiB
C++

// Copyright 2014 Cheng Zhao. All rights reserved.
// Use of this source code is governed by MIT license that can be found in the
// LICENSE file.
#ifndef NATIVE_MATE_SCOPED_PERSISTENT_H_
#define NATIVE_MATE_SCOPED_PERSISTENT_H_
#include "base/memory/ref_counted.h"
#include "v8/include/v8.h"
namespace mate {
// A v8::Persistent handle to a V8 value which destroys and clears the
// underlying handle on destruction.
template <typename T>
class ScopedPersistent {
public:
ScopedPersistent() {
}
explicit ScopedPersistent(v8::Handle<v8::Value> handle) {
reset(v8::Handle<T>::Cast(handle));
}
~ScopedPersistent() {
reset();
}
void reset(v8::Handle<T> handle) {
if (!handle.IsEmpty())
handle_.Reset(GetIsolate(handle), handle);
else
reset();
}
void reset() {
handle_.Reset();
}
bool IsEmpty() const {
return handle_.IsEmpty();
}
v8::Handle<T> NewHandle() const {
if (handle_.IsEmpty())
return v8::Local<T>();
return v8::Local<T>::New(GetIsolate(handle_), handle_);
}
v8::Handle<T> NewHandle(v8::Isolate* isolate) const {
if (handle_.IsEmpty())
return v8::Local<T>();
return v8::Local<T>::New(isolate, handle_);
}
template <typename P>
void MakeWeak(P* parameters,
typename v8::WeakReferenceCallbacks<T, P>::Revivable callback) {
handle_.MakeWeak(parameters, callback);
}
private:
template <typename U>
static v8::Isolate* GetIsolate(v8::Handle<U> object_handle) {
// Only works for v8::Object and its subclasses. Add specialisations for
// anything else.
if (!object_handle.IsEmpty())
return GetIsolate(object_handle->CreationContext());
return v8::Isolate::GetCurrent();
}
static v8::Isolate* GetIsolate(v8::Handle<v8::Context> context_handle) {
if (!context_handle.IsEmpty())
return context_handle->GetIsolate();
return v8::Isolate::GetCurrent();
}
static v8::Isolate* GetIsolate(
v8::Handle<v8::ObjectTemplate> template_handle) {
return v8::Isolate::GetCurrent();
}
template <typename U>
static v8::Isolate* GetIsolate(const U& any_handle) {
return v8::Isolate::GetCurrent();
}
v8::Persistent<T> handle_;
DISALLOW_COPY_AND_ASSIGN(ScopedPersistent);
};
template <typename T>
class RefCountedPersistent : public ScopedPersistent<T>,
public base::RefCounted<RefCountedPersistent<T>> {
public:
RefCountedPersistent() {}
explicit RefCountedPersistent(v8::Handle<v8::Value> handle)
: ScopedPersistent<T>(handle) {
}
protected:
friend class base::RefCounted<RefCountedPersistent<T>>;
~RefCountedPersistent() {}
private:
DISALLOW_COPY_AND_ASSIGN(RefCountedPersistent);
};
} // namespace mate
#endif // NATIVE_MATE_SCOPED_PERSISTENT_H_