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/scoped_ptr.h"
  14 #include "storage/browser/fileapi/file_system_backend.h"
  15 #include "storage/browser/fileapi/task_runner_bound_observer_list.h"
  16 #include "storage/browser/quota/special_storage_policy.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::SpecialStoragePolicy> special_storage_policy,
  77       scoped_refptr<storage::ExternalMountPoints> mount_points,
  78       storage::ExternalMountPoints* system_mount_points);
  79   virtual ~FileSystemBackend();
  80
  81   // Adds system mount points, such as "archive", and "removable". This
  82   // function is no-op if these mount points are already present.
  83   void AddSystemMountPoints();
  84
  85   // Returns true if CrosMountpointProvider can handle |url|, i.e. its
  86   // file system type matches with what this provider supports.
  87   // This could be called on any threads.
  88   static bool CanHandleURL(const storage::FileSystemURL& url);
  89
  90   // storage::FileSystemBackend overrides.
  91   virtual bool CanHandleType(storage::FileSystemType type) const override;
  92   virtual void Initialize(storage::FileSystemContext* context) override;
  93   virtual void ResolveURL(const storage::FileSystemURL& url,
  94                           storage::OpenFileSystemMode mode,
  95                           const OpenFileSystemCallback& callback) override;
  96   virtual storage::AsyncFileUtil* GetAsyncFileUtil(
  97       storage::FileSystemType type) override;
  98   virtual storage::WatcherManager* GetWatcherManager(
  99       storage::FileSystemType type) override;
 100   virtual storage::CopyOrMoveFileValidatorFactory*
 101       GetCopyOrMoveFileValidatorFactory(storage::FileSystemType type,
 102                                         base::File::Error* error_code) override;
 103   virtual storage::FileSystemOperation* CreateFileSystemOperation(
 104       const storage::FileSystemURL& url,
 105       storage::FileSystemContext* context,
 106       base::File::Error* error_code) const override;
 107   virtual bool SupportsStreaming(
 108       const storage::FileSystemURL& url) const override;
 109   virtual bool HasInplaceCopyImplementation(
 110       storage::FileSystemType type) const override;
 111   virtual scoped_ptr<storage::FileStreamReader> CreateFileStreamReader(
 112       const storage::FileSystemURL& path,
 113       int64 offset,
 114       int64 max_bytes_to_read,
 115       const base::Time& expected_modification_time,
 116       storage::FileSystemContext* context) const override;
 117   virtual scoped_ptr<storage::FileStreamWriter> CreateFileStreamWriter(
 118       const storage::FileSystemURL& url,
 119       int64 offset,
 120       storage::FileSystemContext* context) const override;
 121   virtual storage::FileSystemQuotaUtil* GetQuotaUtil() override;
 122   virtual const storage::UpdateObserverList* GetUpdateObservers(
 123       storage::FileSystemType type) const override;
 124   virtual const storage::ChangeObserverList* GetChangeObservers(
 125       storage::FileSystemType type) const override;
 126   virtual const storage::AccessObserverList* GetAccessObservers(
 127       storage::FileSystemType type) const override;
 128
 129   // storage::ExternalFileSystemBackend overrides.
 130   virtual bool IsAccessAllowed(
 131       const storage::FileSystemURL& url) const override;
 132   virtual std::vector<base::FilePath> GetRootDirectories() const override;
 133   virtual void GrantFullAccessToExtension(
 134       const std::string& extension_id) override;
 135   virtual void GrantFileAccessToExtension(
 136       const std::string& extension_id,
 137       const base::FilePath& virtual_path) override;
 138   virtual void RevokeAccessForExtension(
 139       const std::string& extension_id) override;
 140   virtual bool GetVirtualPath(const base::FilePath& filesystem_path,
 141                               base::FilePath* virtual_path) override;
 142   virtual void GetRedirectURLForContents(
 143       const storage::FileSystemURL& url,
 144       const storage::URLCallback& callback) override;
 145
 146  private:
 147   scoped_refptr<storage::SpecialStoragePolicy> special_storage_policy_;
 148   scoped_ptr<FileAccessPermissions> file_access_permissions_;
 149   scoped_ptr<storage::AsyncFileUtil> local_file_util_;
 150
 151   // The delegate instance for the drive file system related operations.
 152   scoped_ptr<FileSystemBackendDelegate> drive_delegate_;
 153
 154   // The delegate instance for the provided file system related operations.
 155   scoped_ptr<FileSystemBackendDelegate> file_system_provider_delegate_;
 156
 157   // The delegate instance for the MTP file system related operations.
 158   scoped_ptr<FileSystemBackendDelegate> mtp_delegate_;
 159
 160   // Mount points specific to the owning context (i.e. per-profile mount
 161   // points).
 162   //
 163   // It is legal to have mount points with the same name as in
 164   // system_mount_points_. Also, mount point paths may overlap with mount point
 165   // paths in system_mount_points_. In both cases mount points in
 166   // |mount_points_| will have a priority.
 167   // E.g. if |mount_points_| map 'foo1' to '/foo/foo1' and
 168   // |file_system_mount_points_| map 'xxx' to '/foo/foo1/xxx', |GetVirtualPaths|
 169   // will resolve '/foo/foo1/xxx/yyy' as 'foo1/xxx/yyy' (i.e. the mapping from
 170   // |mount_points_| will be used).
 171   scoped_refptr<storage::ExternalMountPoints> mount_points_;
 172
 173   // Globally visible mount points. System MountPonts instance should outlive
 174   // all FileSystemBackend instances, so raw pointer is safe.
 175   storage::ExternalMountPoints* system_mount_points_;
 176
 177   DISALLOW_COPY_AND_ASSIGN(FileSystemBackend);
 178 };
 179
 180 }  // namespace chromeos
 181
 182 #endif  // CHROME_BROWSER_CHROMEOS_FILEAPI_FILE_SYSTEM_BACKEND_H_