%PDF-
%PDF-
Mini Shell
Mini Shell
// 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 V8_HEAP_CPPGC_OBJECT_VIEW_H_
#define V8_HEAP_CPPGC_OBJECT_VIEW_H_
#include "include/v8config.h"
#include "src/heap/cppgc/globals.h"
#include "src/heap/cppgc/heap-object-header.h"
#include "src/heap/cppgc/heap-page.h"
namespace cppgc {
namespace internal {
// ObjectView allows accessing a header within the bounds of the actual object.
// It is not exposed externally and does not keep the underlying object alive.
template <AccessMode = AccessMode::kNonAtomic>
class ObjectView final {
public:
V8_INLINE explicit ObjectView(const HeapObjectHeader& header);
V8_INLINE Address Start() const;
V8_INLINE ConstAddress End() const;
V8_INLINE size_t Size() const;
private:
const HeapObjectHeader& header_;
const BasePage* base_page_;
const bool is_large_object_;
};
template <AccessMode access_mode>
ObjectView<access_mode>::ObjectView(const HeapObjectHeader& header)
: header_(header),
base_page_(
BasePage::FromPayload(const_cast<HeapObjectHeader*>(&header_))),
is_large_object_(header_.IsLargeObject<access_mode>()) {
DCHECK_EQ(Start() + Size(), End());
}
template <AccessMode access_mode>
Address ObjectView<access_mode>::Start() const {
return header_.ObjectStart();
}
template <AccessMode access_mode>
ConstAddress ObjectView<access_mode>::End() const {
return is_large_object_ ? LargePage::From(base_page_)->PayloadEnd()
: header_.ObjectEnd<access_mode>();
}
template <AccessMode access_mode>
size_t ObjectView<access_mode>::Size() const {
return is_large_object_ ? LargePage::From(base_page_)->ObjectSize()
: header_.ObjectSize<access_mode>();
}
} // namespace internal
} // namespace cppgc
#endif // V8_HEAP_CPPGC_OBJECT_VIEW_H_
Zerion Mini Shell 1.0