electron/native_mate/scoped_persistent.h
2014-08-10 19:05:25 +08:00

146 lines
3.6 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 "native_mate/converter.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(v8::Isolate* isolate = NULL) : isolate_(isolate) {
}
ScopedPersistent(v8::Handle<v8::Value> handle, v8::Isolate* isolate = NULL)
: isolate_(isolate) {
reset(v8::Handle<T>::Cast(handle));
}
~ScopedPersistent() {
reset();
}
void reset(v8::Handle<T> handle) {
reset(GetIsolate(handle), handle);
}
void reset(v8::Isolate* isolate, v8::Handle<T> handle) {
if (!handle.IsEmpty()) {
isolate_ = isolate;
MATE_PERSISTENT_ASSIGN(T, isolate, handle_, handle);
} else {
reset();
}
}
void reset() {
MATE_PERSISTENT_RESET(handle_);
}
bool IsEmpty() const {
return handle_.IsEmpty();
}
v8::Handle<T> NewHandle() const {
return NewHandle(GetIsolate(handle_));
}
v8::Handle<T> NewHandle(v8::Isolate* isolate) const {
if (handle_.IsEmpty())
return v8::Local<T>();
return MATE_PERSISTENT_TO_LOCAL(T, isolate, handle_);
}
template<typename P, typename C>
void SetWeak(P* parameter, C callback) {
MATE_PERSISTENT_SET_WEAK(handle_, parameter, callback);
}
v8::Isolate* isolate() const { return isolate_; }
private:
template <typename U>
v8::Isolate* GetIsolate(v8::Handle<U> object_handle) const {
// Only works for v8::Object and its subclasses. Add specialisations for
// anything else.
if (!object_handle.IsEmpty())
return GetIsolate(object_handle->CreationContext());
return GetIsolate();
}
#if NODE_VERSION_AT_LEAST(0, 11, 0)
v8::Isolate* GetIsolate(v8::Handle<v8::Context> context_handle) const {
if (!context_handle.IsEmpty())
return context_handle->GetIsolate();
return GetIsolate();
}
#endif
v8::Isolate* GetIsolate(
v8::Handle<v8::ObjectTemplate> template_handle) const {
return GetIsolate();
}
template <typename U>
v8::Isolate* GetIsolate(const U& any_handle) const {
return GetIsolate();
}
v8::Isolate* GetIsolate() const {
if (isolate_)
return isolate_;
else
return v8::Isolate::GetCurrent();
}
v8::Isolate* isolate_;
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);
};
template<typename T>
struct Converter<ScopedPersistent<T> > {
static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
const ScopedPersistent<T>& val) {
return val.NewHandle(isolate);
}
static bool FromV8(v8::Isolate* isolate,
v8::Handle<v8::Value> val,
ScopedPersistent<T>* out) {
v8::Handle<T> converted;
if (!Converter<v8::Handle<T> >::FromV8(isolate, val, &converted))
return false;
out->reset(isolate, converted);
return true;
}
};
} // namespace mate
#endif // NATIVE_MATE_SCOPED_PERSISTENT_H_