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#ifndef COMPOSITOR_RESOURCE_H
#define COMPOSITOR_RESOURCE_H

#include <base/memory/ref_counted.h>
#include <components/viz/common/resources/transferable_resource.h>

#include <QtCore/qglobal.h>
#include <QtGui/qtgui-config.h>

#if QT_CONFIG(opengl)
# include "compositor_resource_fence.h"
#endif

namespace viz {
class SharedBitmap;
} // namespace viz

namespace QtWebEngineCore {

using CompositorResourceId = quint32;

// A resource (OpenGL texture or software shared bitmap).
//
// - Created by the CompositorResourceTracker from a newly submitted
//   CompositorFrame's resource_list.
//
// - Until the frame is committed, its resources are in a 'pending' state and
//   are inaccessible from outside the CompositorResourceTracker.
//
// - Once the frame is committed, its resources can be found via
//   CompositorResourceTracker::findResource.
//
// - A committed resource's fields may not be updated and are safe to use from
//   other threads without synchronization (unless noted otherwise).
struct CompositorResource : viz::TransferableResource
{
    CompositorResource(const viz::TransferableResource &tr) : viz::TransferableResource(tr) {}

    // Counts the number of times this resource has been encountered in
    // CompositorFrames' resource lists.
    //
    // Corresponds to viz::ReturnedResource::count.
    //
    // Updated by CompositorResourceTracker on UI thread.
    int import_count = 1;

    // Identifies the last frame that needed this resource. Used by
    // CompositorResourceTracker to return unused resources back to child
    // compositors.
    //
    // Updated by CompositorResourceTracker on UI thread.
    quint32 last_used_for_frame = 0;

    // Bitmap (if is_software).
    std::unique_ptr<viz::SharedBitmap> bitmap;

#if QT_CONFIG(opengl)
    // OpenGL texture id (if !is_software).
    quint32 texture_id = 0;

    // Should be waited on before using the texture (non-null if !is_software).
    scoped_refptr<CompositorResourceFence> texture_fence;
#endif // QT_CONFIG(opengl)
};

inline bool operator<(const CompositorResource &r1, const CompositorResource &r2)
{
    return r1.id < r2.id;
}

inline bool operator<(const CompositorResource &r, CompositorResourceId id)
{
    return r.id < id;
}

inline bool operator<(CompositorResourceId id, const CompositorResource &r)
{
    return id < r.id;
}

} // namespace QtWebEngineCore

#endif // !COMPOSITOR_RESOURCE_H