// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef INCLUDE_V8_WEAK_CALLBACK_INFO_H_
#define INCLUDE_V8_WEAK_CALLBACK_INFO_H_
#include "v8config.h" // NOLINT(build/include_directory)
namespace v8 {
class Isolate;
namespace api_internal {
V8_EXPORT void InternalFieldOutOfBounds(int index);
} // namespace api_internal
static const int kInternalFieldsInWeakCallback = 2;
static const int kEmbedderFieldsInWeakCallback = 2;
template <typename T>
class WeakCallbackInfo {
public:
using Callback = void (*)(const WeakCallbackInfo<T>& data);
WeakCallbackInfo(Isolate* isolate, T* parameter,
void* embedder_fields[kEmbedderFieldsInWeakCallback],
Callback* callback)
: isolate_(isolate), parameter_(parameter), callback_(callback) {
for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
embedder_fields_[i] = embedder_fields[i];
}
}
V8_INLINE Isolate* GetIsolate() const { return isolate_; }
V8_INLINE T* GetParameter() const { return parameter_; }
V8_INLINE void* GetInternalField(int index) const;
// When first called, the embedder MUST Reset() the Global which triggered the
// callback. The Global itself is unusable for anything else. No v8 other api
// calls may be called in the first callback. Should additional work be
// required, the embedder must set a second pass callback, which will be
// called after all the initial callbacks are processed.
// Calling SetSecondPassCallback on the second pass will immediately crash.
void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
private:
Isolate* isolate_;
T* parameter_;
Callback* callback_;
void* embedder_fields_[kEmbedderFieldsInWeakCallback];
};
/**
* Weakness type for weak handles.
*/
enum class WeakCallbackType {
/**
* Passes a user-defined void* parameter back to the callback.
*/
kParameter,
/**
* Passes the first two internal fields of the object back to the callback.
*/
kInternalFields,
};
template <class T>
void* WeakCallbackInfo<T>::GetInternalField(int index) const {
#ifdef V8_ENABLE_CHECKS
if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
api_internal::InternalFieldOutOfBounds(index);
}
#endif
return embedder_fields_[index];
}
} // namespace v8
#endif // INCLUDE_V8_WEAK_CALLBACK_INFO_H_
