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/weak_ptr.h"
  12 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
  13 #include "chrome/browser/sync_file_system/drive_backend/sync_task.h"
  14 #include "chrome/browser/sync_file_system/drive_backend/sync_task_manager.h"
  15 #include "chrome/browser/sync_file_system/remote_change_processor.h"
  16 #include "chrome/browser/sync_file_system/sync_action.h"
  17 #include "chrome/browser/sync_file_system/sync_callbacks.h"
  18 #include "chrome/browser/sync_file_system/sync_file_metadata.h"
  19 #include "google_apis/drive/drive_api_error_codes.h"
  20 #include "storage/browser/fileapi/file_system_url.h"
  21
  22 namespace drive {
  23 class DriveServiceInterface;
  24 }
  25
  26 namespace google_apis {
  27 class FileList;
  28 class FileResource;
  29 }
  30
  31 namespace storage {
  32 class ScopedFile;
  33 }
  34
  35 namespace sync_file_system {
  36 namespace drive_backend {
  37
  38 class MetadataDatabase;
  39 class SyncEngineContext;
  40
  41 class RemoteToLocalSyncer : public SyncTask {
  42  public:
  43   typedef SyncTaskManager::Continuation Continuation;
  44
  45   // Conflicting trackers will have low priority for RemoteToLocalSyncer so that
  46   // it should be resolved by LocatToRemoteSyncer.
  47   explicit RemoteToLocalSyncer(SyncEngineContext* sync_context);
  48   ~RemoteToLocalSyncer() override;
  49
  50   void RunPreflight(scoped_ptr<SyncTaskToken> token) override;
  51   void RunExclusive(scoped_ptr<SyncTaskToken> token);
  52
  53   const storage::FileSystemURL& url() const { return url_; }
  54   SyncFileType file_type() const { return file_type_; }
  55   SyncAction sync_action() const { return sync_action_; }
  56
  57   bool is_sync_root_deletion() const { return sync_root_deletion_; }
  58
  59  private:
  60   typedef std::vector<std::string> FileIDList;
  61
  62   // TODO(tzik): Update documentation here.
  63   //
  64   // Dispatches remote change to handlers or to SyncCompleted() directly.
  65   // This function uses information only in MetadataDatabase.
  66   //
  67   // If the tracker doesn't have remote metadata:
  68   //   # The file is listed in a folder right before this operation.
  69   //   - Dispatch to HandleMissingRemoteMetadata to fetch remote metadata.
  70   // Else, if the tracker is not active or the dominating app-root is disabled:
  71   //   # Assume the file has remote metadata.
  72   //   - Update the tracker with |missing| flag and empty |md5|.
  73   //   Note: MetadataDatabase may activate the tracker if possible.
  74   // Else, if the tracker doesn't have synced metadata:
  75   //   # Assume the tracker has remote metadata and the tracker is active.
  76   //   # The tracker is not yet synced ever.
  77   //   - If the file is remotely deleted, do nothing to local file and dispatch
  78   //     directly to SyncCompleted().
  79   //   - Else, if the file is a regular file, dispatch to HandleNewFile().
  80   //   - Else, if the file is a folder, dispatch to HandleFolderUpdate().
  81   //   - Else, the file should be an unsupported active file. This should not
  82   //     happen.
  83   // Else, if the remote metadata is marked as deleted:
  84   //   # Most of the remote metadata is missing including title, kind and md5.
  85   //   - Dispatch to HandleDeletion().
  86   // Else, if the tracker has different titles between its synced metadata and
  87   // remote metadata:
  88   //   # Assume the tracker is active and has remote metetadata and synced
  89   //     metadata.
  90   //   # The file is remotely renamed.
  91   //   # Maybe, this can be decomposed to delete and update.
  92   //   - Dispatch to HandleRemoteRename().
  93   // Else, if the tracker's parent is not a parent of the remote metadata:
  94   //   # The file has reorganized.
  95   //   # Maybe, this can be decomposed to delete and update.
  96   //   - Dispatch to HandreReorganize().
  97   // Else, if the folder is a regular file and the md5 in remote metadata does
  98   // not match the md5 in synced metadata:
  99   //   # The file is modified remotely.
 100   //   - Dispatch to HandleContentUpdate().
 101   // Else, if the tracker is a folder and it has needs_folder_listing flag:
 102   //   - Dispatch to HandleFolderContentListing()
 103   // Else, there should be no change to sync.
 104   //   - Dispatch to HandleOfflineSolvable()
 105   void ResolveRemoteChange(scoped_ptr<SyncTaskToken> token);
 106
 107   void MoveToBackground(scoped_ptr<SyncTaskToken> token,
 108                         const Continuation& continuation);
 109   void ContinueAsBackgroundTask(const Continuation& continuation,
 110                                 scoped_ptr<SyncTaskToken> token);
 111
 112   // Handles missing remote metadata case.
 113   // Fetches remote metadata and updates MetadataDatabase by that.  The sync
 114   // operation itself will be deferred to the next sync round.
 115   // Note: if the file is not found, it should be handled as if deleted.
 116   void HandleMissingRemoteMetadata(scoped_ptr<SyncTaskToken> token);
 117   void DidGetRemoteMetadata(scoped_ptr<SyncTaskToken> token,
 118                             google_apis::DriveApiErrorCode error,
 119                             scoped_ptr<google_apis::FileResource> entry);
 120
 121   // This implements the body of the HandleNewFile and HandleContentUpdate.
 122   // If the file doesn't have corresponding local file:
 123   //   - Dispatch to DownloadFile.
 124   // Else, if the local file doesn't have local change:
 125   //   - Dispatch to DownloadFile if the local file is a regular file.
 126   //   - If the local file is a folder, handle this case as a conflict.  Lower
 127   //     the priority of the tracker, and defer further handling to
 128   //     local-to-remote change.
 129   // Else:
 130   //  # The file has local modification.
 131   //  - Handle this case as a conflict.  Lower the priority of the tracker, and
 132   //    defer further handling to local-to-remote change.
 133   void DidPrepareForAddOrUpdateFile(scoped_ptr<SyncTaskToken> token,
 134                                     SyncStatusCode status);
 135
 136   // Handles remotely added folder.  Needs Prepare() call.
 137   // TODO(tzik): Write details and implement this.
 138   void HandleFolderUpdate(scoped_ptr<SyncTaskToken> token);
 139   void DidPrepareForFolderUpdate(scoped_ptr<SyncTaskToken> token,
 140                                  SyncStatusCode status);
 141
 142   // Handles deleted remote file.  Needs Prepare() call.
 143   // If the deleted tracker is the sync-root:
 144   //  - TODO(tzik): Needs special handling.
 145   // Else, if the deleted tracker is a app-root:
 146   //  - TODO(tzik): Needs special handling.
 147   // Else, if the local file is already deleted:
 148   //  - Do nothing anymore to the local, call SyncCompleted().
 149   // Else, if the local file is modified:
 150   //  - Do nothing to the local file, call SyncCompleted().
 151   // Else, if the local file is not modified:
 152   //  - Delete local file.
 153   //  # Note: if the local file is a folder, delete recursively.
 154   void HandleDeletion(scoped_ptr<SyncTaskToken> token);
 155   void DidPrepareForDeletion(scoped_ptr<SyncTaskToken> token,
 156                              SyncStatusCode status);
 157
 158   void HandleFileMove(scoped_ptr<SyncTaskToken> token);
 159
 160   // Handles new file.  Needs Prepare() call.
 161   void HandleContentUpdate(scoped_ptr<SyncTaskToken> token);
 162
 163   void ListFolderContent(scoped_ptr<SyncTaskToken> token);
 164   void DidListFolderContent(
 165       scoped_ptr<SyncTaskToken> token,
 166       scoped_ptr<FileIDList> children,
 167       google_apis::DriveApiErrorCode error,
 168       scoped_ptr<google_apis::FileList> file_list);
 169
 170   void SyncCompleted(scoped_ptr<SyncTaskToken> token, SyncStatusCode status);
 171   void FinalizeSync(scoped_ptr<SyncTaskToken> token, SyncStatusCode status);
 172
 173   void Prepare(const SyncStatusCallback& callback);
 174   void DidPrepare(const SyncStatusCallback& callback,
 175                   SyncStatusCode status,
 176                   const SyncFileMetadata& metadata,
 177                   const FileChangeList& changes);
 178
 179   void DeleteLocalFile(scoped_ptr<SyncTaskToken> token);
 180   void DownloadFile(scoped_ptr<SyncTaskToken> token);
 181   void DidDownloadFile(scoped_ptr<SyncTaskToken> token,
 182                        storage::ScopedFile file,
 183                        google_apis::DriveApiErrorCode error,
 184                        const base::FilePath&);
 185   void DidApplyDownload(scoped_ptr<SyncTaskToken> token,
 186                         storage::ScopedFile,
 187                         SyncStatusCode status);
 188
 189   void CreateFolder(scoped_ptr<SyncTaskToken> token);
 190
 191   // TODO(tzik): After we convert all callbacks to token-passing style,
 192   // drop this function.
 193   SyncStatusCallback SyncCompletedCallback(scoped_ptr<SyncTaskToken> token);
 194
 195   drive::DriveServiceInterface* drive_service();
 196   MetadataDatabase* metadata_database();
 197   RemoteChangeProcessor* remote_change_processor();
 198
 199   SyncEngineContext* sync_context_;  // Not owned.
 200
 201   scoped_ptr<FileTracker> dirty_tracker_;
 202   scoped_ptr<FileMetadata> remote_metadata_;
 203
 204   storage::FileSystemURL url_;
 205   SyncFileType file_type_;
 206   SyncAction sync_action_;
 207
 208   bool prepared_;
 209   bool sync_root_deletion_;
 210
 211   scoped_ptr<SyncFileMetadata> local_metadata_;
 212   scoped_ptr<FileChangeList> local_changes_;
 213
 214   base::WeakPtrFactory<RemoteToLocalSyncer> weak_ptr_factory_;
 215
 216   DISALLOW_COPY_AND_ASSIGN(RemoteToLocalSyncer);
 217 };
 218
 219 }  // namespace drive_backend
 220 }  // namespace sync_file_system
 221
 222 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_