chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.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_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_
   6 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/memory/scoped_vector.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
  14 #include "chrome/browser/sync_file_system/remote_change_processor.h"
  15 #include "chrome/browser/sync_file_system/sync_action.h"
  16 #include "chrome/browser/sync_file_system/sync_callbacks.h"
  17 #include "chrome/browser/sync_file_system/sync_file_metadata.h"
  18 #include "chrome/browser/sync_file_system/sync_task.h"
  19 #include "google_apis/drive/gdata_errorcode.h"
  20 #include "webkit/browser/fileapi/file_system_url.h"
  21
  22 namespace drive {
  23 class DriveServiceInterface;
  24 }
  25
  26 namespace google_apis {
  27 class FileResource;
  28 class ResourceEntry;
  29 class ResourceList;
  30 }
  31
  32 namespace webkit_blob {
  33 class ScopedFile;
  34 }
  35
  36 namespace sync_file_system {
  37 namespace drive_backend {
  38
  39 class MetadataDatabase;
  40 class SyncEngineContext;
  41
  42 class RemoteToLocalSyncer : public SyncTask {
  43  public:
  44   // Conflicting trackers will have low priority for RemoteToLocalSyncer so that
  45   // it should be resolved by LocatToRemoteSyncer.
  46   explicit RemoteToLocalSyncer(SyncEngineContext* sync_context);
  47   virtual ~RemoteToLocalSyncer();
  48
  49   virtual void Run(const SyncStatusCallback& callback) OVERRIDE;
  50
  51   const fileapi::FileSystemURL& url() const { return url_; }
  52   SyncAction sync_action() const { return sync_action_; }
  53
  54   bool is_sync_root_deletion() const { return sync_root_deletion_; }
  55
  56  private:
  57   typedef std::vector<std::string> FileIDList;
  58
  59   // TODO(tzik): Update documentation here.
  60   //
  61   // Dispatches remote change to handlers or to SyncCompleted() directly.
  62   // This function uses information only in MetadataDatabase.
  63   //
  64   // If the tracker doesn't have remote metadata:
  65   //   # The file is listed in a folder right before this operation.
  66   //   - Dispatch to HandleMissingRemoteMetadata to fetch remote metadata.
  67   // Else, if the tracker is not active or the dominating app-root is disabled:
  68   //   # Assume the file has remote metadata.
  69   //   - Update the tracker with |missing| flag and empty |md5|.
  70   //   Note: MetadataDatabase may activate the tracker if possible.
  71   // Else, if the tracker doesn't have synced metadata:
  72   //   # Assume the tracker has remote metadata and the tracker is active.
  73   //   # The tracker is not yet synced ever.
  74   //   - If the file is remotely deleted, do nothing to local file and dispatch
  75   //     directly to SyncCompleted().
  76   //   - Else, if the file is a regular file, dispatch to HandleNewFile().
  77   //   - Else, if the file is a folder, dispatch to HandleFolderUpdate().
  78   //   - Else, the file should be an unsupported active file. This should not
  79   //     happen.
  80   // Else, if the remote metadata is marked as deleted:
  81   //   # Most of the remote metadata is missing including title, kind and md5.
  82   //   - Dispatch to HandleDeletion().
  83   // Else, if the tracker has different titles between its synced metadata and
  84   // remote metadata:
  85   //   # Assume the tracker is active and has remote metetadata and synced
  86   //     metadata.
  87   //   # The file is remotely renamed.
  88   //   # Maybe, this can be decomposed to delete and update.
  89   //   - Dispatch to HandleRemoteRename().
  90   // Else, if the tracker's parent is not a parent of the remote metadata:
  91   //   # The file has reorganized.
  92   //   # Maybe, this can be decomposed to delete and update.
  93   //   - Dispatch to HandreReorganize().
  94   // Else, if the folder is a regular file and the md5 in remote metadata does
  95   // not match the md5 in synced metadata:
  96   //   # The file is modified remotely.
  97   //   - Dispatch to HandleContentUpdate().
  98   // Else, if the tracker is a folder and it has needs_folder_listing flag:
  99   //   - Dispatch to HandleFolderContentListing()
 100   // Else, there should be no change to sync.
 101   //   - Dispatch to HandleOfflineSolvable()
 102   void ResolveRemoteChange(const SyncStatusCallback& callback);
 103
 104   // Handles missing remote metadata case.
 105   // Fetches remote metadata and updates MetadataDatabase by that.  The sync
 106   // operation itself will be deferred to the next sync round.
 107   // Note: if the file is not found, it should be handled as if deleted.
 108   void HandleMissingRemoteMetadata(const SyncStatusCallback& callback);
 109   void DidGetRemoteMetadata(const SyncStatusCallback& callback,
 110                             google_apis::GDataErrorCode error,
 111                             scoped_ptr<google_apis::ResourceEntry> entry);
 112   void DidUpdateDatabaseForRemoteMetadata(const SyncStatusCallback& callback,
 113                                           SyncStatusCode status);
 114
 115   // This implements the body of the HandleNewFile and HandleContentUpdate.
 116   // If the file doesn't have corresponding local file:
 117   //   - Dispatch to DownloadFile.
 118   // Else, if the local file doesn't have local change:
 119   //   - Dispatch to DownloadFile if the local file is a regular file.
 120   //   - If the local file is a folder, handle this case as a conflict.  Lower
 121   //     the priority of the tracker, and defer further handling to
 122   //     local-to-remote change.
 123   // Else:
 124   //  # The file has local modification.
 125   //  - Handle this case as a conflict.  Lower the priority of the tracker, and
 126   //    defer further handling to local-to-remote change.
 127   void DidPrepareForAddOrUpdateFile(const SyncStatusCallback& callback,
 128                                     SyncStatusCode status);
 129
 130   // Handles remotely added folder.  Needs Prepare() call.
 131   // TODO(tzik): Write details and implement this.
 132   void HandleFolderUpdate(const SyncStatusCallback& callback);
 133   void DidPrepareForFolderUpdate(const SyncStatusCallback& callback,
 134                                  SyncStatusCode status);
 135
 136   void HandleSyncRootDeletion(const SyncStatusCallback& callback);
 137
 138   // Handles deleted remote file.  Needs Prepare() call.
 139   // If the deleted tracker is the sync-root:
 140   //  - TODO(tzik): Needs special handling.
 141   // Else, if the deleted tracker is a app-root:
 142   //  - TODO(tzik): Needs special handling.
 143   // Else, if the local file is already deleted:
 144   //  - Do nothing anymore to the local, call SyncCompleted().
 145   // Else, if the local file is modified:
 146   //  - Do nothing to the local file, call SyncCompleted().
 147   // Else, if the local file is not modified:
 148   //  - Delete local file.
 149   //  # Note: if the local file is a folder, delete recursively.
 150   void HandleDeletion(const SyncStatusCallback& callback);
 151   void DidPrepareForDeletion(const SyncStatusCallback& callback,
 152                              SyncStatusCode status);
 153
 154   // Handles new file.  Needs Prepare() call.
 155   void HandleContentUpdate(const SyncStatusCallback& callback);
 156
 157   void ListFolderContent(const SyncStatusCallback& callback);
 158   void DidListFolderContent(
 159       const SyncStatusCallback& callback,
 160       scoped_ptr<FileIDList> children,
 161       google_apis::GDataErrorCode error,
 162       scoped_ptr<google_apis::ResourceList> resource_list);
 163
 164   void SyncCompleted(const SyncStatusCallback& callback, SyncStatusCode status);
 165   void FinalizeSync(const SyncStatusCallback& callback, SyncStatusCode status);
 166
 167
 168   void Prepare(const SyncStatusCallback& callback);
 169   void DidPrepare(const SyncStatusCallback& callback,
 170                   SyncStatusCode status,
 171                   const SyncFileMetadata& metadata,
 172                   const FileChangeList& changes);
 173
 174   void DeleteLocalFile(const SyncStatusCallback& callback);
 175   void DownloadFile(const SyncStatusCallback& callback);
 176   void DidCreateTemporaryFileForDownload(const SyncStatusCallback& callback,
 177                                          webkit_blob::ScopedFile file);
 178   void DidDownloadFile(const SyncStatusCallback& callback,
 179                        webkit_blob::ScopedFile file,
 180                        google_apis::GDataErrorCode error,
 181                        const base::FilePath&);
 182   void DidCalculateMD5ForDownload(const SyncStatusCallback& callback,
 183                                   webkit_blob::ScopedFile file,
 184                                   const std::string& md5);
 185   void DidApplyDownload(const SyncStatusCallback& callback,
 186                         webkit_blob::ScopedFile,
 187                         SyncStatusCode status);
 188
 189   void CreateFolder(const SyncStatusCallback& callback);
 190
 191   drive::DriveServiceInterface* drive_service();
 192   MetadataDatabase* metadata_database();
 193   RemoteChangeProcessor* remote_change_processor();
 194
 195   SyncEngineContext* sync_context_;  // Not owned.
 196
 197   scoped_ptr<FileTracker> dirty_tracker_;
 198   scoped_ptr<FileMetadata> remote_metadata_;
 199
 200   fileapi::FileSystemURL url_;
 201   SyncAction sync_action_;
 202
 203   bool prepared_;
 204   bool sync_root_deletion_;
 205
 206   scoped_ptr<SyncFileMetadata> local_metadata_;
 207   scoped_ptr<FileChangeList> local_changes_;
 208
 209   base::WeakPtrFactory<RemoteToLocalSyncer> weak_ptr_factory_;
 210
 211   DISALLOW_COPY_AND_ASSIGN(RemoteToLocalSyncer);
 212 };
 213
 214 }  // namespace drive_backend
 215 }  // namespace sync_file_system
 216
 217 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_