qv4arraybuffer_p.h

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// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant
#ifndef QV4ARRAYBUFFER_H
#define QV4ARRAYBUFFER_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include "qv4object_p.h"
#include "qv4functionobject_p.h"
#include <QtCore/qarraydatapointer.h>
 
QT_BEGIN_NAMESPACE
 
namespace QV4 {
 
namespace Heap {
 
struct SharedArrayBufferCtor : FunctionObject {
    void init(QV4::ExecutionEngine *engine);
};
 
struct ArrayBufferCtor : SharedArrayBufferCtor {
    void init(QV4::ExecutionEngine *engine);
};
 
struct Q_QML_EXPORT SharedArrayBuffer : Object {
    void init(size_t length);
    void init(const QByteArray& array);
    void destroy();
 
    void setSharedArrayBuffer(bool shared) noexcept { isShared = shared; }
    bool isSharedArrayBuffer() const noexcept { return isShared; }
 
    char *arrayData() noexcept { return arrayDataPointer()->data(); }
    const char *constArrayData() const noexcept { return constArrayDataPointer()->data(); }
    uint arrayDataLength() const noexcept { return constArrayDataPointer().size; }
 
    bool hasSharedArrayData() const noexcept { return constArrayDataPointer().isShared(); }
    bool hasDetachedArrayData() const noexcept { return constArrayDataPointer().isNull(); }
    void detachArrayData() noexcept { arrayDataPointer().clear(); }
 
    bool arrayDataNeedsDetach() const noexcept { return constArrayDataPointer().needsDetach(); }
 
private:
    const QArrayDataPointer<const char> &constArrayDataPointer() const noexcept
    {
        return *reinterpret_cast<const QArrayDataPointer<const char> *>(&arrayDataPointerStorage);
    }
    QArrayDataPointer<char> &arrayDataPointer() noexcept
    {
        return *reinterpret_cast<QArrayDataPointer<char> *>(&arrayDataPointerStorage);
    }
 
    template <typename T>
    struct storage_t { alignas(T) unsigned char data[sizeof(T)]; };
 
    storage_t<QArrayDataPointer<char>>
    arrayDataPointerStorage;
    bool isShared;
};
 
struct Q_QML_EXPORT ArrayBuffer : SharedArrayBuffer {
    void init(size_t length) {
        SharedArrayBuffer::init(length);
        setSharedArrayBuffer(false);
    }
    void init(const QByteArray& array) {
        SharedArrayBuffer::init(array);
        setSharedArrayBuffer(false);
    }
};
 
}
 
struct SharedArrayBufferCtor : FunctionObject
{
    V4_OBJECT2(SharedArrayBufferCtor, FunctionObject)
 
    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
};
 
struct ArrayBufferCtor : SharedArrayBufferCtor
{
    V4_OBJECT2(ArrayBufferCtor, SharedArrayBufferCtor)
 
    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 
    static ReturnedValue method_isView(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
};
 
struct Q_QML_EXPORT SharedArrayBuffer : Object
{
    V4_OBJECT2(SharedArrayBuffer, Object)
    V4_NEEDS_DESTROY
    V4_PROTOTYPE(sharedArrayBufferPrototype)
 
    QByteArray asByteArray() const;
 
    uint arrayDataLength() const { return d()->arrayDataLength(); }
    char *arrayData() { return d()->arrayData(); }
    const char *constArrayData() const { return d()->constArrayData(); }
 
    bool hasSharedArrayData() { return d()->hasSharedArrayData(); }
    bool hasDetachedArrayData() const { return d()->hasDetachedArrayData(); }
    bool isSharedArrayBuffer() const { return d()->isSharedArrayBuffer(); }
};
 
struct Q_QML_EXPORT ArrayBuffer : SharedArrayBuffer
{
    V4_OBJECT2(ArrayBuffer, SharedArrayBuffer)
    V4_NEEDS_DESTROY
    V4_PROTOTYPE(arrayBufferPrototype)
 
    QByteArray asByteArray() const;
    uint arrayDataLength() const { return d()->arrayDataLength(); }
    char *dataData() { if (d()->arrayDataNeedsDetach()) detach(); return d()->arrayData(); }
    // ### is that detach needed?
    const char *constArrayData() const { return d()->constArrayData(); }
    bool hasSharedArrayData() { return d()->hasSharedArrayData(); }
    void detachArrayData() { d()->detachArrayData(); }
 
    void detach();
};
 
struct SharedArrayBufferPrototype : Object
{
    void init(ExecutionEngine *engine, Object *ctor);
 
    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
    static ReturnedValue slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc, bool shared);
};
 
struct ArrayBufferPrototype : SharedArrayBufferPrototype
{
    void init(ExecutionEngine *engine, Object *ctor);
 
    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
};
 
 
} // namespace QV4
 
QT_END_NAMESPACE
 
#endif