chromium/services/video_capture/public/cpp/video_frame_access_handler.h

// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_VIDEO_CAPTURE_PUBLIC_CPP_VIDEO_FRAME_ACCESS_HANDLER_H_
#define SERVICES_VIDEO_CAPTURE_PUBLIC_CPP_VIDEO_FRAME_ACCESS_HANDLER_H_

#include <map>
#include <memory>

#include "base/memory/ref_counted.h"
#include "media/capture/video/video_capture_device.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "services/video_capture/public/mojom/video_frame_handler.mojom.h"

namespace video_capture {

// A referernce counted map of buffer IDs <-> ScopedAccessPermissions. This
// lives on the sender side and the reference counting ensures that the map
// stays alive until all mojo pipes are disconnected, i.e. until all
// VideoFrameAccessHandlerImpl are destroyed.
class ScopedAccessPermissionMap
    : public base::RefCountedThreadSafe<ScopedAccessPermissionMap> { … };

// The implementation of mojom::VideoFrameAccessHandler lives on the sender side
// and handles buffers being released through IPC calls.
class VideoFrameAccessHandlerImpl : public mojom::VideoFrameAccessHandler { … };

// A reference counted object owning a
// mojo::Remote<video_capture::mojom::VideoFrameAccessHandler>. This lives on
// the receiver side and keeps the mojo pipe open while being alive. While the
// mojo pipe is open, the mojom::VideoFrameAccessHandler implementation (e.g.
// VideoFrameAccessHandlerImpl) is also kept alive on the sender side.
class VideoFrameAccessHandlerRemote
    : public base::RefCounted<VideoFrameAccessHandlerRemote> { … };

// Forwards OnFinishedConsumingBuffer() calls to VideoFrameAccessHandlerRemote.
// This can be used by adapters that act as the middleman between a producer of
// frames and mojom::VideoFrameHandler.
class VideoFrameAccessHandlerForwarder : public mojom::VideoFrameAccessHandler { … };

}  // namespace video_capture

#endif  // SERVICES_VIDEO_CAPTURE_PUBLIC_CPP_VIDEO_FRAME_ACCESS_HANDLER_H_