chrome/browser/chromeos/fileapi/file_system_backend.h

   1 // Copyright 2013 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_CHROMEOS_FILEAPI_FILE_SYSTEM_BACKEND_H_
   6 #define CHROME_BROWSER_CHROMEOS_FILEAPI_FILE_SYSTEM_BACKEND_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/files/file_path.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "storage/browser/fileapi/file_system_backend.h"
  16 #include "storage/browser/fileapi/task_runner_bound_observer_list.h"
  17 #include "storage/common/fileapi/file_system_types.h"
  18
  19 namespace storage {
  20 class CopyOrMoveFileValidatorFactory;
  21 class ExternalMountPoints;
  22 class FileSystemURL;
  23 class WatcherManager;
  24 }  // namespace storage
  25
  26 namespace chromeos {
  27
  28 class FileSystemBackendDelegate;
  29 class FileAccessPermissions;
  30
  31 // FileSystemBackend is a Chrome OS specific implementation of
  32 // ExternalFileSystemBackend. This class is responsible for a
  33 // number of things, including:
  34 //
  35 // - Add system mount points
  36 // - Grant/revoke/check file access permissions
  37 // - Create FileSystemOperation per file system type
  38 // - Create FileStreamReader/Writer per file system type
  39 //
  40 // Chrome OS specific mount points:
  41 //
  42 // "Downloads" is a mount point for user's Downloads directory on the local
  43 // disk, where downloaded files are stored by default.
  44 //
  45 // "archive" is a mount point for an archive file, such as a zip file. This
  46 // mount point exposes contents of an archive file via cros_disks and AVFS
  47 // <http://avf.sourceforge.net/>.
  48 //
  49 // "removable" is a mount point for removable media such as an SD card.
  50 // Insertion and removal of removable media are handled by cros_disks.
  51 //
  52 // "oem" is a read-only mount point for a directory containing OEM data.
  53 //
  54 // "drive" is a mount point for Google Drive. Drive is integrated with the
  55 // FileSystem API layer via drive::FileSystemProxy. This mount point is added
  56 // by drive::DriveIntegrationService.
  57 //
  58 // These mount points are placed under the "external" namespace, and file
  59 // system URLs for these mount points look like:
  60 //
  61 //   filesystem:<origin>/external/<mount_name>/...
  62 //
  63 class FileSystemBackend : public storage::ExternalFileSystemBackend {
  64  public:
  65   using storage::FileSystemBackend::OpenFileSystemCallback;
  66
  67   // FileSystemBackend will take an ownership of a |mount_points|
  68   // reference. On the other hand, |system_mount_points| will be kept as a raw
  69   // pointer and it should outlive FileSystemBackend instance.
  70   // The ownerships of |drive_delegate| and |file_system_provider_delegate| are
  71   // also taken.
  72   FileSystemBackend(
  73       FileSystemBackendDelegate* drive_delegate,
  74       FileSystemBackendDelegate* file_system_provider_delegate,
  75       FileSystemBackendDelegate* mtp_delegate,
  76       scoped_refptr<storage::ExternalMountPoints> mount_points,
  77       storage::ExternalMountPoints* system_mount_points);
  78   ~FileSystemBackend() override;
  79
  80   // Adds system mount points, such as "archive", and "removable". This
  81   // function is no-op if these mount points are already present.
  82   void AddSystemMountPoints();
  83
  84   // Returns true if CrosMountpointProvider can handle |url|, i.e. its
  85   // file system type matches with what this provider supports.
  86   // This could be called on any threads.
  87   static bool CanHandleURL(const storage::FileSystemURL& url);
  88
  89   // storage::FileSystemBackend overrides.
  90   bool CanHandleType(storage::FileSystemType type) const override;
  91   void Initialize(storage::FileSystemContext* context) override;
  92   void ResolveURL(const storage::FileSystemURL& url,
  93                   storage::OpenFileSystemMode mode,
  94                   const OpenFileSystemCallback& callback) override;
  95   storage::AsyncFileUtil* GetAsyncFileUtil(
  96       storage::FileSystemType type) override;
  97   storage::WatcherManager* GetWatcherManager(
  98       storage::FileSystemType type) override;
  99   storage::CopyOrMoveFileValidatorFactory* GetCopyOrMoveFileValidatorFactory(
 100       storage::FileSystemType type,
 101       base::File::Error* error_code) override;
 102   storage::FileSystemOperation* CreateFileSystemOperation(
 103       const storage::FileSystemURL& url,
 104       storage::FileSystemContext* context,
 105       base::File::Error* error_code) const override;
 106   bool SupportsStreaming(const storage::FileSystemURL& url) const override;
 107   bool HasInplaceCopyImplementation(
 108       storage::FileSystemType type) const override;
 109   scoped_ptr<storage::FileStreamReader> CreateFileStreamReader(
 110       const storage::FileSystemURL& path,
 111       int64 offset,
 112       int64 max_bytes_to_read,
 113       const base::Time& expected_modification_time,
 114       storage::FileSystemContext* context) const override;
 115   scoped_ptr<storage::FileStreamWriter> CreateFileStreamWriter(
 116       const storage::FileSystemURL& url,
 117       int64 offset,
 118       storage::FileSystemContext* context) const override;
 119   storage::FileSystemQuotaUtil* GetQuotaUtil() override;
 120   const storage::UpdateObserverList* GetUpdateObservers(
 121       storage::FileSystemType type) const override;
 122   const storage::ChangeObserverList* GetChangeObservers(
 123       storage::FileSystemType type) const override;
 124   const storage::AccessObserverList* GetAccessObservers(
 125       storage::FileSystemType type) const override;
 126
 127   // storage::ExternalFileSystemBackend overrides.
 128   bool IsAccessAllowed(const storage::FileSystemURL& url) const override;
 129   std::vector<base::FilePath> GetRootDirectories() const override;
 130   void GrantFileAccessToExtension(const std::string& extension_id,
 131                                   const base::FilePath& virtual_path) override;
 132   void RevokeAccessForExtension(const std::string& extension_id) override;
 133   bool GetVirtualPath(const base::FilePath& filesystem_path,
 134                       base::FilePath* virtual_path) const override;
 135   void GetRedirectURLForContents(
 136       const storage::FileSystemURL& url,
 137       const storage::URLCallback& callback) const override;
 138   storage::FileSystemURL CreateInternalURL(
 139       storage::FileSystemContext* context,
 140       const base::FilePath& entry_path) const override;
 141
 142  private:
 143   scoped_ptr<FileAccessPermissions> file_access_permissions_;
 144   scoped_ptr<storage::AsyncFileUtil> local_file_util_;
 145
 146   // The delegate instance for the drive file system related operations.
 147   scoped_ptr<FileSystemBackendDelegate> drive_delegate_;
 148
 149   // The delegate instance for the provided file system related operations.
 150   scoped_ptr<FileSystemBackendDelegate> file_system_provider_delegate_;
 151
 152   // The delegate instance for the MTP file system related operations.
 153   scoped_ptr<FileSystemBackendDelegate> mtp_delegate_;
 154
 155   // Mount points specific to the owning context (i.e. per-profile mount
 156   // points).
 157   //
 158   // It is legal to have mount points with the same name as in
 159   // system_mount_points_. Also, mount point paths may overlap with mount point
 160   // paths in system_mount_points_. In both cases mount points in
 161   // |mount_points_| will have a priority.
 162   // E.g. if |mount_points_| map 'foo1' to '/foo/foo1' and
 163   // |file_system_mount_points_| map 'xxx' to '/foo/foo1/xxx', |GetVirtualPaths|
 164   // will resolve '/foo/foo1/xxx/yyy' as 'foo1/xxx/yyy' (i.e. the mapping from
 165   // |mount_points_| will be used).
 166   scoped_refptr<storage::ExternalMountPoints> mount_points_;
 167
 168   // Globally visible mount points. System MountPonts instance should outlive
 169   // all FileSystemBackend instances, so raw pointer is safe.
 170   storage::ExternalMountPoints* system_mount_points_;
 171
 172   DISALLOW_COPY_AND_ASSIGN(FileSystemBackend);
 173 };
 174
 175 }  // namespace chromeos
 176
 177 #endif  // CHROME_BROWSER_CHROMEOS_FILEAPI_FILE_SYSTEM_BACKEND_H_