Isolated FS for media devices.

webkit/fileapi/mtp_device_interface_win.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.
+
+#ifndef WEBKIT_FILEAPI_MTP_DEVICE_INTERFACE_WIN_H_
+#define WEBKIT_FILEAPI_MTP_DEVICE_INTERFACE_WIN_H_
+
+#include <PortableDeviceApi.h>
+#include <PortableDevice.h>
+
+#include "base/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "base/platform_file.h"
+#include "base/timer.h"
+#include "base/win/scoped_comptr.h"
+#include "webkit/fileapi/file_system_file_util.h"
+
+namespace base {
+struct PlatformFileInfo;
+class Time;
+}
+
+namespace fileapi {
+
+using base::PlatformFileError;
+using base::PlatformFileInfo;
+
+// Helper class to support MTP device isolated file system operations. This
+// class contains platform specific code to communicate with the attached MTP
+// device. We instantiate this class per MTP device. MTP device is opened for
+// communication during initialization and closed during destruction.
+class MtpDeviceInterfaceWin :
+    public base::RefCountedThreadSafe<MtpDeviceInterfaceWin> {

[kinuko, 2012/07/26 00:38:06]

Keeping this device interface as RefCountedThreadSafe feels dangerous to me. Is
it really safe to call destructor of this class on any threads on any platform? 
Also since RemoveMediaDevice could be used on UI thread if one implements some
blocking operation in the dtor it could stall the UI. 

[kmadhusu, 2012/07/27 02:13:41]

As we discussed, we are going to make the constructor and destructor very light
and to do lazy initialization during file operation. 

+ public:
+  MtpDeviceInterfaceWin(const FilePath::StringType& device_id);
+
+  PlatformFileError GetFileInfo(const FilePath& file_path,
+                                PlatformFileInfo* file_info);
+  FileSystemFileUtil::AbstractFileEnumerator* CreateFileEnumerator(
+      const FilePath& root, bool recursive);
+  PlatformFileError Touch(const FilePath& file_path,
+                          const base::Time& last_access_time,
+                          const base::Time& last_modified_time);
+  bool PathExists(const FilePath& file_path);
+  bool DirectoryExists(const FilePath& file_path);
+  bool IsDirectoryEmpty(const FilePath& file_path);
+
+ protected:
+  friend class base::RefCountedThreadSafe<MtpDeviceInterfaceWin>;
+  virtual ~MtpDeviceInterfaceWin();
+
+ private:
+  bool Init();
+
+  FilePath::StringType device_id_;
+  base::win::ScopedComPtr<IPortableDevice> pdevice_;
+
+  DISALLOW_COPY_AND_ASSIGN(MtpDeviceInterfaceWin);
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_MTP_DEVICE_INTERFACE_WIN_H_