Isolated FS for media devices.

webkit/fileapi/media/media_device_map_service.h

Index: webkit/fileapi/media/media_device_map_service.h
diff --git a/webkit/fileapi/media/media_device_map_service.h b/webkit/fileapi/media/media_device_map_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..e8f2aea6e9c891cc9bd0ff1f6d044637b331b6c5
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+++ b/webkit/fileapi/media/media_device_map_service.h
@@ -0,0 +1,59 @@
+// 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.
+
+#ifndef WEBKIT_FILEAPI_MEDIA_MEDIA_DEVICE_MAP_SERVICE_H_
+#define WEBKIT_FILEAPI_MEDIA_MEDIA_DEVICE_MAP_SERVICE_H_
+
+#include <map>
+
+#include "base/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/singleton.h"
+#include "base/synchronization/lock.h"
+#include "webkit/fileapi/media/media_device_interface_impl.h"
+
+namespace base {
+class SequencedTaskRunner;
+}
+
+namespace fileapi {
+
+// Helper class to manage media device interfaces.
+class FILEAPI_EXPORT MediaDeviceMapService {
+ public:
+  static MediaDeviceMapService* GetInstance();
+
+  // This function is called on IO thread.
+  void MaybeAddMediaDevice(const FilePath::StringType& device_id,
+                           base::SequencedTaskRunner* media_task_runner);
+
+  // This function is called on UI thread.
+  void RemoveMediaDevice(const FilePath::StringType& device_id);
+
+  // This function is called on IO thread. Returns NULL on failure.
+  MediaDeviceInterfaceImpl* GetMediaDevice(
+      const FilePath::StringType& device_id);
+
+ private:
+  MediaDeviceMapService();

[Lei Zhang, 2012/07/31 20:48:18]

Add a note to say "access through GetInstance()"

[kmadhusu, 2012/08/01 01:43:59]

Done.

+  ~MediaDeviceMapService();
+
+  friend struct DefaultSingletonTraits<MediaDeviceMapService>;

[Lei Zhang, 2012/07/31 20:48:18]

nit: friends and typedefs go above the ctor/dtor

[kmadhusu, 2012/08/01 01:43:59]

Done.

+
+  typedef scoped_refptr<MediaDeviceInterfaceImpl> MediaDeviceRefPtr;
+  typedef std::map<FilePath::StringType, MediaDeviceRefPtr> MediaDeviceMap;
+
+  base::Lock media_device_map_lock_;
+
+  // Store a map of attached mtp devices.
+  // Key: Device id.
+  // Value: MtpDeviceInterface.
+  MediaDeviceMap media_device_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaDeviceMapService);
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_MEDIA_MEDIA_DEVICE_MAP_SERVICE_H_