Make the Linux System Monitor implementation track all devices

chrome/browser/media_gallery/media_device_notifications_linux.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.
-
-// MediaDeviceNotificationsLinux listens for mount point changes and notifies
-// the SystemMonitor about the addition and deletion of media devices.
-
-#ifndef CHROME_BROWSER_MEDIA_GALLERY_MEDIA_DEVICE_NOTIFICATIONS_LINUX_H_
-#define CHROME_BROWSER_MEDIA_GALLERY_MEDIA_DEVICE_NOTIFICATIONS_LINUX_H_
-
-#if defined(OS_CHROMEOS)
-#error "Use the ChromeOS-specific implementation instead."
-#endif
-
-#include <map>
-#include <set>
-#include <string>
-#include <utility>
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/files/file_path_watcher.h"
-#include "base/memory/ref_counted.h"
-#include "content/public/browser/browser_thread.h"
-
-class FilePath;
-
-// Gets the media device information given a |device_path|. On success,
-// returns true and fills in |name| and |id|.
-typedef bool (*GetDeviceInfoFunc)(const std::string& device_path,
-                                  std::string* id,
-                                  string16* name);
-
-namespace chrome {
-
-class MediaDeviceNotificationsLinux
-    : public base::RefCountedThreadSafe<MediaDeviceNotificationsLinux,
-          content::BrowserThread::DeleteOnFileThread> {
- public:
-  explicit MediaDeviceNotificationsLinux(const FilePath& path);
-
-  // Must be called for MediaDeviceNotificationsLinux to work.
-  void Init();
-
- protected:
-  // Only for use in unit tests.
-  MediaDeviceNotificationsLinux(const FilePath& path,
-                                GetDeviceInfoFunc getDeviceInfo);
-
-  // Avoids code deleting the object while there are references to it.
-  // Aside from the base::RefCountedThreadSafe friend class, and derived
-  // classes, any attempts to call this dtor will result in a compile-time
-  // error.
-  virtual ~MediaDeviceNotificationsLinux();
-
-  virtual void OnFilePathChanged(const FilePath& path, bool error);
-
- private:
-  friend class base::RefCountedThreadSafe<MediaDeviceNotificationsLinux>;
-  friend class base::DeleteHelper<MediaDeviceNotificationsLinux>;
-  friend struct content::BrowserThread::DeleteOnThread<
-      content::BrowserThread::FILE>;
-
-  // Structure to save mounted device information such as device path and unique
-  // identifier.
-  struct MountDeviceAndId {
-    std::string mount_device;
-    std::string device_id;
-  };
-
-  // Mapping of mount points to MountDeviceAndId.
-  typedef std::map<std::string, MountDeviceAndId> MountMap;
-
-  // (mount point, mount device)
-  // Helper Map to get new entries from mtab file.
-  typedef std::map<std::string, std::string> MountPointDeviceMap;
-
-  void InitOnFileThread();
-
-  // Parses mtab file and find all changes.
-  void UpdateMtab();
-
-  // Reads mtab file entries into |mtab|.
-  void ReadMtab(MountPointDeviceMap* mtab);
-
-  // Checks and adds |mount_device| as media device given the |mount_point|.
-  void CheckAndAddMediaDevice(const std::string& mount_device,
-                              const std::string& mount_point);
-
-  // Removes media device with a given device id.
-  void RemoveOldDevice(const std::string& device_id);
-
-  // Whether Init() has been called or not.
-  bool initialized_;
-
-  // Mtab file that lists the mount points.
-  const FilePath mtab_path_;
-
-  // Watcher for |mtab_path_|.
-  base::files::FilePathWatcher file_watcher_;
-
-  // Mapping of relevant mount points and their corresponding mount devices.
-  // Keep in mind on Linux, a device can be mounted at multiple mount points,
-  // and multiple devices can be mounted at a mount point.
-  MountMap mount_info_map_;
-
-  // Set of known file systems that we care about.
-  std::set<std::string> known_file_systems_;
-
-  // Function handler to get device information. This is useful to set a mock
-  // handler for unit testing.
-  GetDeviceInfoFunc get_device_info_func_;
-
-  DISALLOW_COPY_AND_ASSIGN(MediaDeviceNotificationsLinux);
-};
-
-}  // namespace chrome
-
-#endif  // CHROME_BROWSER_MEDIA_GALLERY_MEDIA_DEVICE_NOTIFICATIONS_LINUX_H_