/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef WEBGPU_INSTANCE_PROVIDER_H_

#define WEBGPU_INSTANCE_PROVIDER_H_

#include "mozilla/AlreadyAddRefed.h"

#include "mozilla/Maybe.h"

#include "mozilla/RefPtr.h"

class nsCycleCollectionTraversalCallback;

class nsIGlobalObject;

namespace mozilla {

namespace webgpu {

class Instance;

class InstanceProvider

{

private:

    nsIGlobalObject* const mGlobal;

    mutable Maybe<RefPtr<Instance>> mInstance;

protected:

    explicit InstanceProvider(nsIGlobalObject* global);

    virtual ~InstanceProvider();

public:

    already_AddRefed<Instance> Webgpu() const;

    nsIGlobalObject* GetParentObject() const { return mGlobal; }

    void CcTraverse(nsCycleCollectionTraversalCallback&) const;

    void CcUnlink();

};

template<typename T>

void

ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& callback,

                            const Maybe<T>& field,

                            const char* name, uint32_t flags)

{

    if (field) {

        CycleCollectionNoteChild(callback, field.value(), name, flags);

    }

}

template<typename T>

void

ImplCycleCollectionUnlink(Maybe<T>& field)

{

    field = Nothing();

}

} // namespace webgpu

} // namespace mozilla

#endif // WEBGPU_INSTANCE_PROVIDER_H_