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 <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/files/file_path.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/synchronization/lock.h"
  16 #include "webkit/browser/fileapi/file_system_backend.h"
  17 #include "webkit/browser/quota/special_storage_policy.h"
  18 #include "webkit/browser/webkit_storage_browser_export.h"
  19 #include "webkit/common/fileapi/file_system_types.h"
  20
  21 namespace fileapi {
  22 class CopyOrMoveFileValidatorFactory;
  23 class ExternalMountPoints;
  24 class FileSystemFileUtil;
  25 class FileSystemURL;
  26 class IsolatedContext;
  27 }
  28
  29 namespace chromeos {
  30
  31 class FileSystemBackendDelegate;
  32 class FileAccessPermissions;
  33
  34 // FileSystemBackend is a Chrome OS specific implementation of
  35 // ExternalFileSystemBackend. This class is responsible for a
  36 // number of things, including:
  37 //
  38 // - Add system mount points
  39 // - Grant/revoke/check file access permissions
  40 // - Create FileSystemOperation per file system type
  41 // - Create FileStreamReader/Writer per file system type
  42 //
  43 // Chrome OS specific mount points:
  44 //
  45 // "Downloads" is a mount point for user's Downloads directory on the local
  46 // disk, where downloaded files are stored by default.
  47 //
  48 // "archive" is a mount point for an archive file, such as a zip file. This
  49 // mount point exposes contents of an archive file via cros_disks and AVFS
  50 // <http://avf.sourceforge.net/>.
  51 //
  52 // "removable" is a mount point for removable media such as an SD card.
  53 // Insertion and removal of removable media are handled by cros_disks.
  54 //
  55 // "oem" is a read-only mount point for a directory containing OEM data.
  56 //
  57 // "drive" is a mount point for Google Drive. Drive is integrated with the
  58 // FileSystem API layer via drive::FileSystemProxy. This mount point is added
  59 // by drive::DriveIntegrationService.
  60 //
  61 // These mount points are placed under the "external" namespace, and file
  62 // system URLs for these mount points look like:
  63 //
  64 //   filesystem:<origin>/external/<mount_name>/...
  65 //
  66 class FileSystemBackend : public fileapi::ExternalFileSystemBackend {
  67  public:
  68   using fileapi::FileSystemBackend::OpenFileSystemCallback;
  69
  70   // FileSystemBackend will take an ownership of a |mount_points|
  71   // reference. On the other hand, |system_mount_points| will be kept as a raw
  72   // pointer and it should outlive FileSystemBackend instance.
  73   // The ownership of |drive_delegate| is also taken.
  74   FileSystemBackend(
  75       FileSystemBackendDelegate* drive_delegate,
  76       scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy,
  77       scoped_refptr<fileapi::ExternalMountPoints> mount_points,
  78       fileapi::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 fileapi::FileSystemURL& url);
  89
  90   // fileapi::FileSystemBackend overrides.
  91   virtual bool CanHandleType(fileapi::FileSystemType type) const OVERRIDE;
  92   virtual void Initialize(fileapi::FileSystemContext* context) OVERRIDE;
  93   virtual void OpenFileSystem(
  94       const GURL& origin_url,
  95       fileapi::FileSystemType type,
  96       fileapi::OpenFileSystemMode mode,
  97       const OpenFileSystemCallback& callback) OVERRIDE;
  98   virtual fileapi::AsyncFileUtil* GetAsyncFileUtil(
  99       fileapi::FileSystemType type) OVERRIDE;
 100   virtual fileapi::CopyOrMoveFileValidatorFactory*
 101       GetCopyOrMoveFileValidatorFactory(
 102           fileapi::FileSystemType type,
 103           base::PlatformFileError* error_code) OVERRIDE;
 104   virtual fileapi::FileSystemOperation* CreateFileSystemOperation(
 105       const fileapi::FileSystemURL& url,
 106       fileapi::FileSystemContext* context,
 107       base::PlatformFileError* error_code) const OVERRIDE;
 108   virtual scoped_ptr<webkit_blob::FileStreamReader> CreateFileStreamReader(
 109       const fileapi::FileSystemURL& path,
 110       int64 offset,
 111       const base::Time& expected_modification_time,
 112       fileapi::FileSystemContext* context) const OVERRIDE;
 113   virtual scoped_ptr<fileapi::FileStreamWriter> CreateFileStreamWriter(
 114       const fileapi::FileSystemURL& url,
 115       int64 offset,
 116       fileapi::FileSystemContext* context) const OVERRIDE;
 117   virtual fileapi::FileSystemQuotaUtil* GetQuotaUtil() OVERRIDE;
 118
 119   // fileapi::ExternalFileSystemBackend overrides.
 120   virtual bool IsAccessAllowed(const fileapi::FileSystemURL& url)
 121       const OVERRIDE;
 122   virtual std::vector<base::FilePath> GetRootDirectories() const OVERRIDE;
 123   virtual void GrantFullAccessToExtension(
 124       const std::string& extension_id) OVERRIDE;
 125   virtual void GrantFileAccessToExtension(
 126       const std::string& extension_id,
 127       const base::FilePath& virtual_path) OVERRIDE;
 128   virtual void RevokeAccessForExtension(
 129       const std::string& extension_id) OVERRIDE;
 130   virtual bool GetVirtualPath(const base::FilePath& filesystem_path,
 131                               base::FilePath* virtual_path) OVERRIDE;
 132
 133  private:
 134   scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
 135   scoped_ptr<FileAccessPermissions> file_access_permissions_;
 136   scoped_ptr<fileapi::AsyncFileUtil> local_file_util_;
 137
 138   // The Delegate instance for the drive file system related operation.
 139   scoped_ptr<FileSystemBackendDelegate> drive_delegate_;
 140
 141   // Mount points specific to the owning context (i.e. per-profile mount
 142   // points).
 143   //
 144   // It is legal to have mount points with the same name as in
 145   // system_mount_points_. Also, mount point paths may overlap with mount point
 146   // paths in system_mount_points_. In both cases mount points in
 147   // |mount_points_| will have a priority.
 148   // E.g. if |mount_points_| map 'foo1' to '/foo/foo1' and
 149   // |file_system_mount_points_| map 'xxx' to '/foo/foo1/xxx', |GetVirtualPaths|
 150   // will resolve '/foo/foo1/xxx/yyy' as 'foo1/xxx/yyy' (i.e. the mapping from
 151   // |mount_points_| will be used).
 152   scoped_refptr<fileapi::ExternalMountPoints> mount_points_;
 153
 154   // Globally visible mount points. System MountPonts instance should outlive
 155   // all FileSystemBackend instances, so raw pointer is safe.
 156   fileapi::ExternalMountPoints* system_mount_points_;
 157
 158   DISALLOW_COPY_AND_ASSIGN(FileSystemBackend);
 159 };
 160
 161 }  // namespace chromeos
 162
 163 #endif  // CHROME_BROWSER_CHROMEOS_FILEAPI_FILE_SYSTEM_BACKEND_H_