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