components/storage_monitor/mtab_watcher_linux.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // MtabWatcherLinux listens for mount point changes from a mtab file and
   6 // notifies a StorageMonitorLinux about them.
   7 // MtabWatcherLinux lives on the FILE thread.
   8
   9 #ifndef COMPONENTS_STORAGE_MONITOR_MTAB_WATCHER_LINUX_H_
  10 #define COMPONENTS_STORAGE_MONITOR_MTAB_WATCHER_LINUX_H_
  11
  12 #if defined(OS_CHROMEOS)
  13 #error "ChromeOS does not use MtabWatcherLinux."
  14 #endif
  15
  16 #include <map>
  17
  18 #include "base/basictypes.h"
  19 #include "base/files/file_path.h"
  20 #include "base/files/file_path_watcher.h"
  21 #include "base/memory/weak_ptr.h"
  22
  23 namespace storage_monitor {
  24
  25 class MtabWatcherLinux {
  26  public:
  27   // (mount point, mount device)
  28   // A mapping from mount point to mount device, as extracted from the mtab
  29   // file.
  30   typedef std::map<base::FilePath, base::FilePath> MountPointDeviceMap;
  31
  32   class Delegate {
  33    public:
  34     virtual ~Delegate() {}
  35
  36     // Parses |new_mtab| and find all changes. Called on the UI thread.
  37     virtual void UpdateMtab(const MountPointDeviceMap& new_mtab) = 0;
  38   };
  39
  40   MtabWatcherLinux(const base::FilePath& mtab_path,
  41                    base::WeakPtr<Delegate> delegate);
  42   ~MtabWatcherLinux();
  43
  44  private:
  45   // Reads mtab file entries into |mtab|.
  46   void ReadMtab() const;
  47
  48   // Called when |mtab_path_| changes.
  49   void OnFilePathChanged(const base::FilePath& path, bool error);
  50
  51   // Mtab file that lists the mount points.
  52   const base::FilePath mtab_path_;
  53
  54   // Watcher for |mtab_path_|.
  55   base::FilePathWatcher file_watcher_;
  56
  57   base::WeakPtr<Delegate> delegate_;
  58
  59   base::WeakPtrFactory<MtabWatcherLinux> weak_ptr_factory_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(MtabWatcherLinux);
  62 };
  63
  64 }  // namespace storage_monitor
  65
  66 #endif  // COMPONENTS_STORAGE_MONITOR_MTAB_WATCHER_LINUX_H_