[Mojo Video Capture] Introduce abstraction BuildableVideoCaptureDevice

content/browser/renderer_host/media/video_capture_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // VideoCaptureManager is used to open/close, start/stop, enumerate available
 // video capture devices, and manage VideoCaptureController's.
 // All functions are expected to be called from Browser::IO thread. Some helper
 // functions (*OnDeviceThread) will dispatch operations to the device thread.
 // VideoCaptureManager will open OS dependent instances of VideoCaptureDevice.
 // A device can only be opened once.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_
 
 #include <list>
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/observer_list.h"
 #include "base/process/process_handle.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/elapsed_timer.h"
 #include "build/build_config.h"
+#include "content/browser/renderer_host/media/buildable_video_capture_device.h"
 #include "content/browser/renderer_host/media/media_stream_provider.h"
 #include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
 #include "content/common/content_export.h"
 #include "content/common/media/media_stream_options.h"
 #include "media/base/video_facing.h"
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video/video_capture_device_factory.h"
 #include "media/capture/video_capture_types.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/application_status_listener.h"
 #endif
 
 namespace content {
 class VideoCaptureController;
 class VideoCaptureControllerEventHandler;
 
 // VideoCaptureManager opens/closes and start/stops video capture devices.
-class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
+class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider,
+                                           public BuildableDeviceCallbacks {
  public:
   using VideoCaptureDevice = media::VideoCaptureDevice;
 
   // Callback used to signal the completion of a controller lookup.
   using DoneCB =
       base::Callback<void(const base::WeakPtr<VideoCaptureController>&)>;
 
   VideoCaptureManager(
       std::unique_ptr<media::VideoCaptureDeviceFactory> factory,
       scoped_refptr<base::SingleThreadTaskRunner> device_task_runner);
@@ skipping 131 matching lines @@
   // Some devices had troubles when stopped and restarted quickly, so the device
   // is only stopped when Chrome is sent to background and not when, e.g., a tab
   // is hidden, see http://crbug.com/582295.
   void OnApplicationStateChange(base::android::ApplicationState state);
 #endif
 
   using EnumerationCallback =
       base::Callback<void(const media::VideoCaptureDeviceDescriptors&)>;
   void EnumerateDevices(const EnumerationCallback& client_callback);
 
+  // BuildableDeviceCallbacks implementation:
+  const media::VideoCaptureDeviceDescriptor* LookupDeviceDescriptor(
+      const std::string& id) override;
+  void WillStartDevice(media::VideoFacingMode facing_mode) override;
+  void DidStartDevice(VideoCaptureController* controller) override;
+  void OnDeviceStartFailed(VideoCaptureController* controller) override;
+
   // Retrieves camera calibration information for a particular device. Returns
   // nullopt_t if the |device_id| is not found or camera calibration information
   // is not available for the device.  Camera calibration is cached during
   // device(s) enumeration.
   base::Optional<CameraCalibration> GetCameraCalibration(
       const std::string& device_id);
 
  private:
   class CaptureDeviceStartRequest;
-  struct DeviceEntry;
   struct DeviceInfo;
 
   using SessionMap = std::map<media::VideoCaptureSessionId, MediaStreamDevice>;
-  using DeviceEntries = std::vector<std::unique_ptr<DeviceEntry>>;
   using DeviceInfos = std::vector<DeviceInfo>;
   using DeviceStartQueue = std::list<CaptureDeviceStartRequest>;
   using VideoCaptureDeviceDescriptor = media::VideoCaptureDeviceDescriptor;
   using VideoCaptureDeviceDescriptors = media::VideoCaptureDeviceDescriptors;
 
   ~VideoCaptureManager() override;
 
   // Helpers to report an event to our Listener.
   void OnOpened(MediaStreamType type,
                 media::VideoCaptureSessionId capture_session_id);
   void OnClosed(MediaStreamType type,
                 media::VideoCaptureSessionId capture_session_id);
   void OnDevicesInfoEnumerated(base::ElapsedTimer* timer,
                                const EnumerationCallback& client_callback,
                                const DeviceInfos& new_devices_info_cache);
 
-  bool IsOnDeviceThread() const;
-
   // Consolidates the cached devices list with the list of currently connected
   // devices in the system |names_snapshot|. Retrieves the supported formats of
   // the new devices and sends the new cache to OnDevicesInfoEnumerated().
   void ConsolidateDevicesInfoOnDeviceThread(
       base::Callback<void(const DeviceInfos&)> on_devices_enumerated_callback,
       const DeviceInfos& old_device_info_cache,
       std::unique_ptr<VideoCaptureDeviceDescriptors> descriptors_snapshot);
 
-  // Checks to see if |entry| has no clients left on its controller. If so,
-  // remove it from the list of devices, and delete it asynchronously. |entry|
-  // may be freed by this function.
-  void DestroyDeviceEntryIfNoClients(DeviceEntry* entry);
+  // Checks to see if |controller| has no clients left on its controller. If so,
+  // remove it from the list of devices, and delete it asynchronously.
+  // |controller| may be freed by this function.
+  void DestroyDeviceEntryIfNoClients(VideoCaptureController* controller);

[miu, 2017/03/16 00:01:36]

Looks like you might have wanted to also rename this. Something like
DestroyControllerIfNoClients().

[chfremer, 2017/03/16 17:39:39]

Done.

 
-  // Finds a DeviceEntry in different ways: by |session_id|, by its |device_id|
-  // and |type| (if it is already opened), by its |controller| or by its
-  // |serial_id|. In all cases, if not found, nullptr is returned.
-  DeviceEntry* GetDeviceEntryBySessionId(int session_id);
-  DeviceEntry* GetDeviceEntryByTypeAndId(MediaStreamType type,
-                                         const std::string& device_id) const;
-  DeviceEntry* GetDeviceEntryByController(
-      const VideoCaptureController* controller) const;
-  DeviceEntry* GetDeviceEntryBySerialId(int serial_id) const;
+  // Finds a VideoCaptureController in different ways: by |session_id|, by its
+  // |device_id| and |type| (if it is already opened), by its |controller| or by
+  // its |serial_id|. In all cases, if not found, nullptr is returned.
+  VideoCaptureController* LookupControllerBySessionId(int session_id);
+  VideoCaptureController* LookupControllerByTypeAndId(
+      MediaStreamType type,
+      const std::string& device_id) const;
+  bool IsControllerPointerValid(const VideoCaptureController* controller) const;
+  VideoCaptureController* LookupControllerBySerialId(int serial_id) const;
+  scoped_refptr<VideoCaptureController> GetControllerSharedRefFromSerialId(
+      int serial_id) const;
 
   // Finds the device info by |id| in |devices_info_cache_|, or nullptr.
   DeviceInfo* GetDeviceInfoById(const std::string& id);
 
-  // Finds a DeviceEntry entry for the indicated |capture_session_id|, creating
-  // a fresh one if necessary. Returns nullptr if said |capture_session_id| is
-  // invalid.
-  DeviceEntry* GetOrCreateDeviceEntry(
+  // Finds a VideoCaptureController for the indicated |capture_session_id|,
+  // creating a fresh one if necessary. Returns nullptr if said
+  // |capture_session_id| is invalid.
+  VideoCaptureController* GetOrCreateController(
       media::VideoCaptureSessionId capture_session_id,
       const media::VideoCaptureParams& params);
 
   // Starting a capture device can take 1-2 seconds.
   // To avoid multiple unnecessary start/stop commands to the OS, each start
   // request is queued in |device_start_queue_|.
   // QueueStartDevice creates a new entry in |device_start_queue_| and posts a
   // request to start the device on the device thread unless there is
   // another request pending start.
   void QueueStartDevice(media::VideoCaptureSessionId session_id,
-                        DeviceEntry* entry,
+                        VideoCaptureController* controller,
                         const media::VideoCaptureParams& params);
-  void OnDeviceStarted(
-      int serial_id,
-      std::unique_ptr<VideoCaptureDevice> device);
-  void DoStopDevice(DeviceEntry* entry);
+  void DoStopDevice(VideoCaptureController* controller);
   void HandleQueuedStartRequest();
 
-  // Creates and Starts a new VideoCaptureDevice. The resulting
-  // VideoCaptureDevice is returned to the IO-thread and stored in
-  // a DeviceEntry in |devices_|. Ownership of |client| passes to
-  // the device.
-  std::unique_ptr<VideoCaptureDevice> DoStartDeviceCaptureOnDeviceThread(
-      const VideoCaptureDeviceDescriptor& descriptor,
-      const media::VideoCaptureParams& params,
-      std::unique_ptr<VideoCaptureDevice::Client> client);
-
-  std::unique_ptr<VideoCaptureDevice> DoStartTabCaptureOnDeviceThread(
-      const std::string& device_id,
-      const media::VideoCaptureParams& params,
-      std::unique_ptr<VideoCaptureDevice::Client> client);
-
-  std::unique_ptr<VideoCaptureDevice> DoStartDesktopCaptureOnDeviceThread(
-      const std::string& device_id,
-      const media::VideoCaptureParams& params,
-      std::unique_ptr<VideoCaptureDevice::Client> client);
-
-  // Stops and destroys the VideoCaptureDevice held in |device|.
-  void DoStopDeviceOnDeviceThread(std::unique_ptr<VideoCaptureDevice> device);
-
   void MaybePostDesktopCaptureWindowId(media::VideoCaptureSessionId session_id);
-  void SetDesktopCaptureWindowIdOnDeviceThread(
-      media::VideoCaptureDevice* device,
-      gfx::NativeViewId window_id);
-
-  // Internal versions of the Image Capture public ones, for delayed execution.
-  void DoGetPhotoCapabilities(
-      VideoCaptureDevice::GetPhotoCapabilitiesCallback callback,
-      VideoCaptureDevice* device);
-  void DoSetPhotoOptions(
-      VideoCaptureDevice::SetPhotoOptionsCallback callback,
-      media::mojom::PhotoSettingsPtr settings,
-      VideoCaptureDevice* device);
-  void DoTakePhoto(VideoCaptureDevice::TakePhotoCallback callback,
-                   VideoCaptureDevice* device);
 
 #if defined(OS_ANDROID)
   void ReleaseDevices();
   void ResumeDevices();
 
   std::unique_ptr<base::android::ApplicationStatusListener>
       app_status_listener_;
   bool application_state_has_running_activities_;
 #endif
 
   // The message loop of media stream device thread, where VCD's live.
   scoped_refptr<base::SingleThreadTaskRunner> device_task_runner_;
 
   // Only accessed on Browser::IO thread.
   base::ObserverList<MediaStreamProviderListener> listeners_;
   media::VideoCaptureSessionId new_capture_session_id_;
 
   // An entry is kept in this map for every session that has been created via
   // the Open() entry point. The keys are session_id's. This map is used to
   // determine which device to use when StartCaptureForClient() occurs. Used
   // only on the IO thread.
   SessionMap sessions_;
 
-  // Currently opened DeviceEntry instances (each owning a VideoCaptureDevice -
-  // VideoCaptureController pair). The device may or may not be started. This
-  // member is only accessed on IO thread.
-  DeviceEntries devices_;
+  // Currently opened VideoCaptureController instances. The device may or may
+  // not be started. This member is only accessed on IO thread.
+  std::vector<scoped_refptr<VideoCaptureController>> controllers_;
 
   DeviceStartQueue device_start_queue_;
 
   // Queue to keep photo-associated requests waiting for a device to initialize,
   // bundles a session id integer and an associated photo-related request.
-  std::list<std::pair<int, base::Callback<void(media::VideoCaptureDevice*)>>>
-      photo_request_queue_;
+  std::list<std::pair<int, base::Closure>> photo_request_queue_;
 
   // Device creation factory injected on construction from MediaStreamManager or
   // from the test harness.
   std::unique_ptr<media::VideoCaptureDeviceFactory>
       video_capture_device_factory_;
 
   base::ObserverList<media::VideoCaptureObserver> capture_observers_;
 
   // Local cache of the enumerated video capture devices' names and capture
   // supported formats. A snapshot of the current devices and their capabilities
   // is composed in VideoCaptureDeviceFactory::EnumerateDeviceNames() and
   // ConsolidateDevicesInfoOnDeviceThread(), and this snapshot is used to update
   // this list in OnDevicesInfoEnumerated(). GetDeviceSupportedFormats() will
   // use this list if the device is not started, otherwise it will retrieve the
   // active device capture format from the VideoCaptureController associated.
   DeviceInfos devices_info_cache_;
 
   // Map used by DesktopCapture.
   std::map<media::VideoCaptureSessionId, gfx::NativeViewId>
       notification_window_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_