chrome/browser/media_galleries/fileapi/mtp_device_map_service.h

   1 // Copyright (c) 2012 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 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_MTP_DEVICE_MAP_SERVICE_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_MTP_DEVICE_MAP_SERVICE_H_
   7
   8 #include <map>
   9
  10 #include "base/files/file_path.h"
  11 #include "base/lazy_instance.h"
  12 #include "base/threading/thread_checker.h"
  13
  14 class MTPDeviceAsyncDelegate;
  15
  16 // This class provides media transfer protocol (MTP) device delegate to
  17 // complete media file system operations.
  18 // Lives on the IO thread in production.
  19 // TODO(gbillock): Make this class owned by the MediaFileSystemRegistry.
  20 class MTPDeviceMapService {
  21  public:
  22   static MTPDeviceMapService* GetInstance();
  23
  24   // Gets the media device delegate associated with |filesystem_id|.
  25   // Return NULL if the |filesystem_id| is no longer valid (e.g. because the
  26   // corresponding device is detached, etc).
  27   // Called on the IO thread.
  28   MTPDeviceAsyncDelegate* GetMTPDeviceAsyncDelegate(
  29       const std::string& filesystem_id);
  30
  31   // Register that an MTP filesystem is in use for the given |device_location|.
  32   void RegisterMTPFileSystem(const base::FilePath::StringType& device_location,
  33                              const std::string& filesystem_id,
  34                              const bool read_only);
  35
  36   // Removes the MTP entry associated with the given
  37   // |device_location|. Signals the MTPDeviceMapService to destroy the
  38   // delegate if there are no more uses of it.
  39   void RevokeMTPFileSystem(const std::string& filesystem_id);
  40
  41  private:
  42   friend struct base::DefaultLazyInstanceTraits<MTPDeviceMapService>;
  43
  44   // Adds the MTP device delegate to the map service. |device_location|
  45   // specifies the mount location of the MTP device.
  46   // Called on the IO thread.
  47   void AddAsyncDelegate(const base::FilePath::StringType& device_location,
  48                         const bool read_only,
  49                         MTPDeviceAsyncDelegate* delegate);
  50
  51   // Removes the MTP device delegate from the map service. |device_location|
  52   // specifies the mount location of the MTP device.
  53   // Called on the IO thread.
  54   void RemoveAsyncDelegate(const base::FilePath::StringType& device_location,
  55                            const bool read_only);
  56
  57   // A key to be used in AsyncDelegateMap and MTPDeviceUsageMap.
  58   typedef base::FilePath::StringType AsyncDelegateKey;
  59
  60   // Gets a key from |device_location| and |read_only|.
  61   static AsyncDelegateKey GetAsyncDelegateKey(
  62       const base::FilePath::StringType& device_location,
  63       const bool read_only);
  64
  65   // Mapping of device_location and MTPDeviceAsyncDelegate* object. It is safe
  66   // to store and access the raw pointer. This class operates on the IO thread.
  67   typedef std::map<AsyncDelegateKey, MTPDeviceAsyncDelegate*> AsyncDelegateMap;
  68
  69   // Map a filesystem id (fsid) to an MTP device location.
  70   typedef std::pair<base::FilePath::StringType, bool> MTPDeviceInfo;
  71   typedef std::map<std::string, MTPDeviceInfo> MTPDeviceFileSystemMap;
  72
  73   // Map a MTP or PTP device location to a count of current uses of that
  74   // location.
  75   typedef std::map<AsyncDelegateKey, int> MTPDeviceUsageMap;
  76
  77   // Get access to this class using GetInstance() method.
  78   MTPDeviceMapService();
  79   ~MTPDeviceMapService();
  80
  81   // Map of attached mtp device async delegates.
  82   AsyncDelegateMap async_delegate_map_;
  83
  84   MTPDeviceFileSystemMap mtp_device_map_;
  85
  86   MTPDeviceUsageMap mtp_device_usage_map_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(MTPDeviceMapService);
  89 };
  90
  91 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_MTP_DEVICE_MAP_SERVICE_H_