chrome/browser/sync_file_system/drive_backend/local_to_remote_syncer.cc

   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 #include "chrome/browser/sync_file_system/drive_backend/local_to_remote_syncer.h"
   6
   7 #include <string>
   8 #include <vector>
   9
  10 #include "base/callback.h"
  11 #include "base/format_macros.h"
  12 #include "base/location.h"
  13 #include "base/logging.h"
  14 #include "base/sequenced_task_runner.h"
  15 #include "base/strings/stringprintf.h"
  16 #include "base/task_runner_util.h"
  17 #include "chrome/browser/drive/drive_api_util.h"
  18 #include "chrome/browser/drive/drive_service_interface.h"
  19 #include "chrome/browser/drive/drive_uploader.h"
  20 #include "chrome/browser/sync_file_system/drive_backend/callback_helper.h"
  21 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_constants.h"
  22 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_util.h"
  23 #include "chrome/browser/sync_file_system/drive_backend/folder_creator.h"
  24 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
  25 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
  26 #include "chrome/browser/sync_file_system/drive_backend/sync_engine_context.h"
  27 #include "chrome/browser/sync_file_system/drive_backend/sync_task_manager.h"
  28 #include "chrome/browser/sync_file_system/drive_backend/sync_task_token.h"
  29 #include "chrome/browser/sync_file_system/logger.h"
  30 #include "google_apis/drive/drive_api_parser.h"
  31 #include "net/base/mime_util.h"
  32 #include "storage/common/fileapi/file_system_util.h"
  33
  34 namespace sync_file_system {
  35 namespace drive_backend {
  36
  37 namespace {
  38
  39 scoped_ptr<FileTracker> FindTrackerByID(MetadataDatabase* metadata_database,
  40                                         int64 tracker_id) {
  41   scoped_ptr<FileTracker> tracker(new FileTracker);
  42   if (metadata_database->FindTrackerByTrackerID(tracker_id, tracker.get()))
  43     return tracker.Pass();
  44   return scoped_ptr<FileTracker>();
  45 }
  46
  47 bool GetKnownChangeID(MetadataDatabase* metadata_database,
  48                       const std::string& file_id,
  49                       int64* change_id) {
  50   FileMetadata remote_file_metadata;
  51   if (!metadata_database->FindFileByFileID(file_id, &remote_file_metadata))
  52     return false;
  53   *change_id = remote_file_metadata.details().change_id();
  54   return true;
  55 }
  56
  57 bool IsLocalFileMissing(const SyncFileMetadata& local_metadata,
  58                         const FileChange& local_change) {
  59   return local_metadata.file_type == SYNC_FILE_TYPE_UNKNOWN ||
  60          local_change.IsDelete();
  61 }
  62
  63 std::string GetMimeTypeFromTitle(const base::FilePath& title) {
  64   base::FilePath::StringType extension = title.Extension();
  65   std::string mime_type;
  66   if (extension.empty() ||
  67       !net::GetWellKnownMimeTypeFromExtension(extension.substr(1), &mime_type))
  68     return kMimeTypeOctetStream;
  69   return mime_type;
  70 }
  71
  72 }  // namespace
  73
  74 LocalToRemoteSyncer::LocalToRemoteSyncer(SyncEngineContext* sync_context,
  75                                          const SyncFileMetadata& local_metadata,
  76                                          const FileChange& local_change,
  77                                          const base::FilePath& local_path,
  78                                          const storage::FileSystemURL& url)
  79     : sync_context_(sync_context),
  80       local_change_(local_change),
  81       local_is_missing_(IsLocalFileMissing(local_metadata, local_change)),
  82       local_path_(local_path),
  83       url_(url),
  84       file_type_(SYNC_FILE_TYPE_UNKNOWN),
  85       sync_action_(SYNC_ACTION_NONE),
  86       remote_file_change_id_(0),
  87       retry_on_success_(false),
  88       needs_remote_change_listing_(false),
  89       weak_ptr_factory_(this) {
  90   DCHECK(local_is_missing_ ||
  91          local_change.file_type() == local_metadata.file_type)
  92       << local_change.DebugString() << " metadata:" << local_metadata.file_type;
  93 }
  94
  95 LocalToRemoteSyncer::~LocalToRemoteSyncer() {
  96 }
  97
  98 void LocalToRemoteSyncer::RunPreflight(scoped_ptr<SyncTaskToken> token) {
  99   token->InitializeTaskLog("Local -> Remote");
 100
 101   if (!IsContextReady()) {
 102     token->RecordLog("Context not ready.");
 103     SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_FAILED);
 104     return;
 105   }
 106
 107   token->RecordLog(base::StringPrintf(
 108       "Start: %s on %s@%s %s",
 109       local_change_.DebugString().c_str(),
 110       url_.path().AsUTF8Unsafe().c_str(),
 111       url_.origin().host().c_str(),
 112       local_is_missing_ ? "(missing)" : ""));
 113
 114   if (local_is_missing_ && !local_change_.IsDelete()) {
 115     // Stray file, we can just return.
 116     token->RecordLog("Missing file for non-delete change.");
 117     SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_OK);
 118     return;
 119   }
 120
 121   std::string app_id = url_.origin().host();
 122   base::FilePath path = url_.path();
 123
 124   scoped_ptr<FileTracker> active_ancestor_tracker(new FileTracker);
 125   base::FilePath active_ancestor_path;
 126   if (!metadata_database()->FindNearestActiveAncestor(
 127           app_id, path,
 128           active_ancestor_tracker.get(), &active_ancestor_path)) {
 129     // The app is disabled or not registered.
 130     token->RecordLog("App is disabled or not registered");
 131     SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_UNKNOWN_ORIGIN);
 132     return;
 133   }
 134   DCHECK(active_ancestor_tracker->active());
 135   DCHECK(active_ancestor_tracker->has_synced_details());
 136   const FileDetails& active_ancestor_details =
 137       active_ancestor_tracker->synced_details();
 138
 139   // TODO(tzik): Consider handling
 140   // active_ancestor_tracker->synced_details().missing() case.
 141
 142   DCHECK(active_ancestor_details.file_kind() == FILE_KIND_FILE ||
 143          active_ancestor_details.file_kind() == FILE_KIND_FOLDER);
 144
 145   base::FilePath missing_entries;
 146   if (active_ancestor_path.empty()) {
 147     missing_entries = path;
 148   } else if (active_ancestor_path != path) {
 149     if (!active_ancestor_path.AppendRelativePath(path, &missing_entries)) {
 150       NOTREACHED();
 151       token->RecordLog(base::StringPrintf(
 152           "Detected invalid ancestor: %s",
 153           active_ancestor_path.value().c_str()));
 154       SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_FAILED);
 155       return;
 156     }
 157   }
 158
 159   std::vector<base::FilePath::StringType> missing_components;
 160   storage::VirtualPath::GetComponents(missing_entries, &missing_components);
 161
 162   if (!missing_components.empty()) {
 163     if (local_is_missing_) {
 164       token->RecordLog("Both local and remote are marked missing");
 165       // !IsDelete() but SYNC_FILE_TYPE_UNKNOWN could happen when a file is
 166       // deleted by recursive deletion (which is not recorded by tracker)
 167       // but there're remaining changes for the same file in the tracker.
 168
 169       // Local file is deleted and remote file is missing, already deleted or
 170       // not yet synced.  There is nothing to do for the file.
 171       SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_OK);
 172       return;
 173     }
 174   }
 175
 176   if (missing_components.size() > 1) {
 177     // The original target doesn't have remote file and parent.
 178     // Try creating the parent first.
 179     if (active_ancestor_details.file_kind() == FILE_KIND_FOLDER) {
 180       remote_parent_folder_tracker_ = active_ancestor_tracker.Pass();
 181       target_path_ = active_ancestor_path.Append(missing_components[0]);
 182       token->RecordLog("Detected missing parent folder.");
 183
 184       retry_on_success_ = true;
 185       MoveToBackground(base::Bind(&LocalToRemoteSyncer::CreateRemoteFolder,
 186                                   weak_ptr_factory_.GetWeakPtr()),
 187                        token.Pass());
 188       return;
 189     }
 190
 191     DCHECK(active_ancestor_details.file_kind() == FILE_KIND_FILE);
 192     remote_parent_folder_tracker_ =
 193         FindTrackerByID(metadata_database(),
 194                         active_ancestor_tracker->parent_tracker_id());
 195     remote_file_tracker_ = active_ancestor_tracker.Pass();
 196     target_path_ = active_ancestor_path;
 197     token->RecordLog("Detected non-folder file in its path.");
 198
 199     retry_on_success_ = true;
 200     MoveToBackground(base::Bind(&LocalToRemoteSyncer::DeleteRemoteFile,
 201                                 weak_ptr_factory_.GetWeakPtr()),
 202                      token.Pass());
 203     return;
 204   }
 205
 206   if (missing_components.empty()) {
 207     // The original target has remote active file/folder.
 208     remote_parent_folder_tracker_ =
 209         FindTrackerByID(metadata_database(),
 210                         active_ancestor_tracker->parent_tracker_id());
 211     remote_file_tracker_ = active_ancestor_tracker.Pass();
 212     target_path_ = url_.path();
 213     DCHECK(target_path_ == active_ancestor_path);
 214
 215     if (remote_file_tracker_->dirty()) {
 216       token->RecordLog(base::StringPrintf(
 217           "Detected conflicting dirty tracker:%" PRId64,
 218            remote_file_tracker_->tracker_id()));
 219       // Both local and remote file has pending modification.
 220       HandleConflict(token.Pass());
 221       return;
 222     }
 223
 224     // Non-conflicting file/folder update case.
 225     HandleExistingRemoteFile(token.Pass());
 226     return;
 227   }
 228
 229   DCHECK(local_change_.IsAddOrUpdate());
 230   DCHECK_EQ(1u, missing_components.size());
 231   // The original target has remote parent folder and doesn't have remote active
 232   // file.
 233   // Upload the file as a new file or create a folder.
 234   remote_parent_folder_tracker_ = active_ancestor_tracker.Pass();
 235   target_path_ = url_.path();
 236   DCHECK(target_path_ == active_ancestor_path.Append(missing_components[0]));
 237   if (local_change_.file_type() == SYNC_FILE_TYPE_FILE) {
 238     token->RecordLog("Detected a new file.");
 239     MoveToBackground(base::Bind(&LocalToRemoteSyncer::UploadNewFile,
 240                                 weak_ptr_factory_.GetWeakPtr()),
 241                      token.Pass());
 242     return;
 243   }
 244
 245   token->RecordLog("Detected a new folder.");
 246   MoveToBackground(base::Bind(&LocalToRemoteSyncer::CreateRemoteFolder,
 247                               weak_ptr_factory_.GetWeakPtr()),
 248                    token.Pass());
 249 }
 250
 251 void LocalToRemoteSyncer::MoveToBackground(const Continuation& continuation,
 252                                            scoped_ptr<SyncTaskToken> token) {
 253   scoped_ptr<TaskBlocker> blocker(new TaskBlocker);
 254   blocker->app_id = url_.origin().host();
 255   blocker->paths.push_back(target_path_);
 256
 257   if (remote_file_tracker_) {
 258     if (!GetKnownChangeID(metadata_database(),
 259                           remote_file_tracker_->file_id(),
 260                           &remote_file_change_id_)) {
 261       NOTREACHED();
 262       SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 263       return;
 264     }
 265
 266     blocker->tracker_ids.push_back(remote_file_tracker_->tracker_id());
 267     blocker->file_ids.push_back(remote_file_tracker_->file_id());
 268   }
 269
 270   // Run current task as a background task with |blocker|.
 271   // After the invocation of ContinueAsBackgroundTask
 272   SyncTaskManager::UpdateTaskBlocker(
 273       token.Pass(), blocker.Pass(),
 274       base::Bind(&LocalToRemoteSyncer::ContinueAsBackgroundTask,
 275                  weak_ptr_factory_.GetWeakPtr(),
 276                  continuation));
 277 }
 278
 279 void LocalToRemoteSyncer::ContinueAsBackgroundTask(
 280     const Continuation& continuation,
 281     scoped_ptr<SyncTaskToken> token) {
 282   // The SyncTask runs as a background task beyond this point.
 283   // Note that any task can run between MoveToBackground() and
 284   // ContinueAsBackgroundTask(), so we need to make sure other tasks didn't
 285   // affect to the current LocalToRemoteSyncer task.
 286   //
 287   // - For RemoteToLocalSyncer, it doesn't actually run beyond
 288   //   PrepareForProcessRemoteChange() since it should be blocked in
 289   //   LocalFileSyncService.
 290   // - For ListChangesTask, it may update FileMetatada together with |change_id|
 291   //   and may delete FileTracker.  So, ensure |change_id| is not changed and
 292   //   check if FileTracker still exists.
 293   // - For UninstallAppTask, it may also delete FileMetadata and FileTracker.
 294   //   Check if FileTracker still exists.
 295   // - Others, SyncEngineInitializer and RegisterAppTask doesn't affect to
 296   //   LocalToRemoteSyncer.
 297   if (remote_file_tracker_) {
 298     int64 latest_change_id = 0;
 299     if (!GetKnownChangeID(metadata_database(),
 300                           remote_file_tracker_->file_id(),
 301                           &latest_change_id) ||
 302         latest_change_id > remote_file_change_id_) {
 303       SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 304       return;
 305     }
 306
 307     if (!metadata_database()->FindTrackerByTrackerID(
 308             remote_file_tracker_->tracker_id(), nullptr)) {
 309       SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 310       return;
 311     }
 312   }
 313
 314   continuation.Run(token.Pass());
 315 }
 316
 317 void LocalToRemoteSyncer::SyncCompleted(scoped_ptr<SyncTaskToken> token,
 318                                         SyncStatusCode status) {
 319   if (status == SYNC_STATUS_OK && retry_on_success_)
 320     status = SYNC_STATUS_RETRY;
 321
 322   if (needs_remote_change_listing_)
 323     status = SYNC_STATUS_FILE_BUSY;
 324
 325   token->RecordLog(base::StringPrintf(
 326       "Finished: action=%s, status=%s for %s@%s",
 327       SyncActionToString(sync_action_),
 328       SyncStatusCodeToString(status),
 329       target_path_.AsUTF8Unsafe().c_str(),
 330       url_.origin().host().c_str()));
 331
 332   SyncTaskManager::NotifyTaskDone(token.Pass(), status);
 333 }
 334
 335 void LocalToRemoteSyncer::HandleConflict(scoped_ptr<SyncTaskToken> token) {
 336   DCHECK(remote_file_tracker_);
 337   DCHECK(remote_file_tracker_->has_synced_details());
 338   DCHECK(remote_file_tracker_->active());
 339   DCHECK(remote_file_tracker_->dirty());
 340
 341   if (local_is_missing_) {
 342     SyncCompleted(token.Pass(), SYNC_STATUS_OK);
 343     return;
 344   }
 345
 346   if (local_change_.IsFile()) {
 347     // Upload the conflicting file as a new file and let ConflictResolver
 348     // resolve it.
 349     MoveToBackground(base::Bind(&LocalToRemoteSyncer::UploadNewFile,
 350                                 weak_ptr_factory_.GetWeakPtr()),
 351                      token.Pass());
 352     return;
 353   }
 354
 355   DCHECK(local_change_.IsDirectory());
 356   // Check if we can reuse the remote folder.
 357   FileMetadata remote_file_metadata;
 358   if (!metadata_database()->FindFileByFileID(
 359           remote_file_tracker_->file_id(), &remote_file_metadata)) {
 360     NOTREACHED();
 361     MoveToBackground(base::Bind(&LocalToRemoteSyncer::CreateRemoteFolder,
 362                                 weak_ptr_factory_.GetWeakPtr()),
 363                      token.Pass());
 364     return;
 365   }
 366
 367   const FileDetails& remote_details = remote_file_metadata.details();
 368   base::FilePath title = storage::VirtualPath::BaseName(target_path_);
 369   if (!remote_details.missing() &&
 370       remote_details.file_kind() == FILE_KIND_FOLDER &&
 371       remote_details.title() == title.AsUTF8Unsafe() &&
 372       HasFileAsParent(remote_details,
 373                       remote_parent_folder_tracker_->file_id())) {
 374     MoveToBackground(
 375         base::Bind(&LocalToRemoteSyncer::UpdateTrackerForReusedFolder,
 376                    weak_ptr_factory_.GetWeakPtr(),
 377                    remote_details),
 378         token.Pass());
 379     return;
 380   }
 381
 382   MoveToBackground(base::Bind(&LocalToRemoteSyncer::CreateRemoteFolder,
 383                               weak_ptr_factory_.GetWeakPtr()),
 384                    token.Pass());
 385 }
 386
 387 void LocalToRemoteSyncer::UpdateTrackerForReusedFolder(
 388     const FileDetails& details,
 389     scoped_ptr<SyncTaskToken> token) {
 390   SyncStatusCode status = metadata_database()->UpdateTracker(
 391       remote_file_tracker_->tracker_id(), details);
 392   SyncCompleted(token.Pass(), status);
 393 }
 394
 395 void LocalToRemoteSyncer::HandleExistingRemoteFile(
 396     scoped_ptr<SyncTaskToken> token) {
 397   DCHECK(remote_file_tracker_);
 398   DCHECK(!remote_file_tracker_->dirty());
 399   DCHECK(remote_file_tracker_->active());
 400   DCHECK(remote_file_tracker_->has_synced_details());
 401
 402   if (local_is_missing_) {
 403     // Local file deletion for existing remote file.
 404     MoveToBackground(base::Bind(&LocalToRemoteSyncer::DeleteRemoteFile,
 405                                 weak_ptr_factory_.GetWeakPtr()),
 406                      token.Pass());
 407     return;
 408   }
 409
 410   DCHECK(local_change_.IsAddOrUpdate());
 411   DCHECK(local_change_.IsFile() || local_change_.IsDirectory());
 412
 413   const FileDetails& synced_details = remote_file_tracker_->synced_details();
 414   DCHECK(synced_details.file_kind() == FILE_KIND_FILE ||
 415          synced_details.file_kind() == FILE_KIND_FOLDER);
 416   if (local_change_.IsFile()) {
 417     if (synced_details.file_kind() == FILE_KIND_FILE) {
 418       // Non-conflicting local file update to existing remote regular file.
 419       MoveToBackground(base::Bind(&LocalToRemoteSyncer::UploadExistingFile,
 420                                   weak_ptr_factory_.GetWeakPtr()),
 421                        token.Pass());
 422       return;
 423     }
 424
 425     DCHECK_EQ(FILE_KIND_FOLDER, synced_details.file_kind());
 426     // Non-conflicting local file update to existing remote *folder*.
 427     // Assuming this case as local folder deletion + local file creation, delete
 428     // the remote folder and upload the file.
 429     retry_on_success_ = true;
 430     MoveToBackground(base::Bind(&LocalToRemoteSyncer::DeleteRemoteFile,
 431                                 weak_ptr_factory_.GetWeakPtr()),
 432                      token.Pass());
 433     return;
 434   }
 435
 436   DCHECK(local_change_.IsDirectory());
 437   if (synced_details.file_kind() == FILE_KIND_FILE) {
 438     // Non-conflicting local folder creation to existing remote *file*.
 439     // Assuming this case as local file deletion + local folder creation, delete
 440     // the remote file and create a remote folder.
 441     retry_on_success_ = true;
 442     MoveToBackground(base::Bind(&LocalToRemoteSyncer::DeleteRemoteFile,
 443                                 weak_ptr_factory_.GetWeakPtr()),
 444                      token.Pass());
 445     return;
 446   }
 447
 448   // Non-conflicting local folder creation to existing remote folder.
 449   DCHECK_EQ(FILE_KIND_FOLDER, synced_details.file_kind());
 450   SyncCompleted(token.Pass(), SYNC_STATUS_OK);
 451 }
 452
 453 void LocalToRemoteSyncer::DeleteRemoteFile(scoped_ptr<SyncTaskToken> token) {
 454   DCHECK(remote_file_tracker_);
 455   DCHECK(remote_file_tracker_->has_synced_details());
 456
 457   switch (remote_file_tracker_->synced_details().file_kind()) {
 458     case FILE_KIND_UNSUPPORTED:
 459       NOTREACHED();
 460       file_type_ = SYNC_FILE_TYPE_UNKNOWN;
 461       break;
 462     case FILE_KIND_FILE:
 463       file_type_ = SYNC_FILE_TYPE_FILE;
 464       break;
 465     case FILE_KIND_FOLDER:
 466       file_type_ = SYNC_FILE_TYPE_DIRECTORY;
 467       break;
 468   }
 469   sync_action_ = SYNC_ACTION_DELETED;
 470   drive_service()->DeleteResource(
 471       remote_file_tracker_->file_id(),
 472       remote_file_tracker_->synced_details().etag(),
 473       base::Bind(&LocalToRemoteSyncer::DidDeleteRemoteFile,
 474                  weak_ptr_factory_.GetWeakPtr(), base::Passed(&token)));
 475 }
 476
 477 void LocalToRemoteSyncer::DidDeleteRemoteFile(
 478     scoped_ptr<SyncTaskToken> token,
 479     google_apis::DriveApiErrorCode error) {
 480   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
 481   if (status != SYNC_STATUS_OK &&
 482       error != google_apis::HTTP_NOT_FOUND &&
 483       error != google_apis::HTTP_PRECONDITION &&
 484       error != google_apis::HTTP_CONFLICT) {
 485     SyncCompleted(token.Pass(), status);
 486     return;
 487   }
 488
 489   // Handle NOT_FOUND case as SUCCESS case.
 490   // For PRECONDITION / CONFLICT case, the remote file is modified since the
 491   // last sync completed.  As our policy for deletion-modification conflict
 492   // resolution, ignore the local deletion.
 493   if (status == SYNC_STATUS_OK ||
 494       error == google_apis::HTTP_NOT_FOUND) {
 495     SyncStatusCode status = metadata_database()->UpdateByDeletedRemoteFile(
 496         remote_file_tracker_->file_id());
 497     SyncCompleted(token.Pass(), status);
 498     return;
 499   }
 500
 501   SyncCompleted(token.Pass(), SYNC_STATUS_OK);
 502 }
 503
 504 void LocalToRemoteSyncer::UploadExistingFile(scoped_ptr<SyncTaskToken> token) {
 505   DCHECK(remote_file_tracker_);
 506   DCHECK(remote_file_tracker_->has_synced_details());
 507   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 508
 509   const std::string local_file_md5 = drive::util::GetMd5Digest(local_path_,
 510                                                                nullptr);
 511   if (local_file_md5 == remote_file_tracker_->synced_details().md5()) {
 512     // Local file is not changed.
 513     SyncCompleted(token.Pass(), SYNC_STATUS_OK);
 514     return;
 515   }
 516
 517   file_type_ = SYNC_FILE_TYPE_FILE;
 518   sync_action_ = SYNC_ACTION_UPDATED;
 519
 520   drive::UploadExistingFileOptions options;
 521   options.etag = remote_file_tracker_->synced_details().etag();
 522   drive_uploader()->UploadExistingFile(
 523       remote_file_tracker_->file_id(),
 524       local_path_,
 525       "application/octet_stream",
 526       options,
 527       base::Bind(&LocalToRemoteSyncer::DidUploadExistingFile,
 528                  weak_ptr_factory_.GetWeakPtr(), base::Passed(&token)),
 529       google_apis::ProgressCallback());
 530 }
 531
 532 void LocalToRemoteSyncer::DidUploadExistingFile(
 533     scoped_ptr<SyncTaskToken> token,
 534     google_apis::DriveApiErrorCode error,
 535     const GURL&,
 536     scoped_ptr<google_apis::FileResource> entry) {
 537   if (error == google_apis::HTTP_PRECONDITION ||
 538       error == google_apis::HTTP_CONFLICT ||
 539       error == google_apis::HTTP_NOT_FOUND) {
 540     // The remote file has unfetched remote change.  Fetch latest metadata and
 541     // update database with it.
 542     // TODO(tzik): Consider adding local side low-priority dirtiness handling to
 543     // handle this as ListChangesTask.
 544
 545     needs_remote_change_listing_ = true;
 546     UpdateRemoteMetadata(
 547         remote_file_tracker_->file_id(),
 548         token.Pass());
 549     return;
 550   }
 551
 552   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
 553   if (status != SYNC_STATUS_OK) {
 554     SyncCompleted(token.Pass(), status);
 555     return;
 556   }
 557
 558   if (!entry) {
 559     NOTREACHED();
 560     SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 561     return;
 562   }
 563
 564   DCHECK(entry);
 565   status = metadata_database()->UpdateByFileResource(*entry);
 566   if (status != SYNC_STATUS_OK) {
 567     SyncCompleted(token.Pass(), status);
 568     return;
 569   }
 570
 571   FileMetadata file;
 572   if (!metadata_database()->FindFileByFileID(
 573           remote_file_tracker_->file_id(), &file)) {
 574     NOTREACHED();
 575     SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 576     return;
 577   }
 578
 579   const FileDetails& details = file.details();
 580   base::FilePath title = storage::VirtualPath::BaseName(target_path_);
 581   if (!details.missing() &&
 582       details.file_kind() == FILE_KIND_FILE &&
 583       details.title() == title.AsUTF8Unsafe() &&
 584       HasFileAsParent(details,
 585                       remote_parent_folder_tracker_->file_id())) {
 586     SyncStatusCode status = metadata_database()->UpdateTracker(
 587         remote_file_tracker_->tracker_id(), file.details());
 588     SyncCompleted(token.Pass(), status);
 589     return;
 590   }
 591
 592   SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 593 }
 594
 595 void LocalToRemoteSyncer::UpdateRemoteMetadata(
 596     const std::string& file_id,
 597     scoped_ptr<SyncTaskToken> token) {
 598   DCHECK(remote_file_tracker_);
 599
 600   drive_service()->GetFileResource(
 601       file_id,
 602       base::Bind(&LocalToRemoteSyncer::DidGetRemoteMetadata,
 603                  weak_ptr_factory_.GetWeakPtr(),
 604                  file_id, base::Passed(&token)));
 605 }
 606
 607 void LocalToRemoteSyncer::DidGetRemoteMetadata(
 608     const std::string& file_id,
 609     scoped_ptr<SyncTaskToken> token,
 610     google_apis::DriveApiErrorCode error,
 611     scoped_ptr<google_apis::FileResource> entry) {
 612   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 613
 614   if (error == google_apis::HTTP_NOT_FOUND) {
 615     retry_on_success_ = true;
 616     SyncStatusCode status =
 617         metadata_database()->UpdateByDeletedRemoteFile(file_id);
 618     SyncCompleted(token.Pass(), status);
 619     return;
 620   }
 621
 622   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
 623   if (status != SYNC_STATUS_OK) {
 624     SyncCompleted(token.Pass(), status);
 625     return;
 626   }
 627
 628   if (!entry) {
 629     NOTREACHED();
 630     SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 631     return;
 632   }
 633
 634   retry_on_success_ = true;
 635   status = metadata_database()->UpdateByFileResource(*entry);
 636   SyncCompleted(token.Pass(), status);
 637 }
 638
 639 void LocalToRemoteSyncer::UploadNewFile(scoped_ptr<SyncTaskToken> token) {
 640   DCHECK(remote_parent_folder_tracker_);
 641
 642   file_type_ = SYNC_FILE_TYPE_FILE;
 643   sync_action_ = SYNC_ACTION_ADDED;
 644   base::FilePath title = storage::VirtualPath::BaseName(target_path_);
 645   drive_uploader()->UploadNewFile(
 646       remote_parent_folder_tracker_->file_id(), local_path_,
 647       title.AsUTF8Unsafe(), GetMimeTypeFromTitle(title),
 648       drive::UploadNewFileOptions(),
 649       base::Bind(&LocalToRemoteSyncer::DidUploadNewFile,
 650                  weak_ptr_factory_.GetWeakPtr(), base::Passed(&token)),
 651       google_apis::ProgressCallback());
 652 }
 653
 654 void LocalToRemoteSyncer::DidUploadNewFile(
 655     scoped_ptr<SyncTaskToken> token,
 656     google_apis::DriveApiErrorCode error,
 657     const GURL& upload_location,
 658     scoped_ptr<google_apis::FileResource> entry) {
 659   if (error == google_apis::HTTP_NOT_FOUND)
 660     needs_remote_change_listing_ = true;
 661
 662   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
 663   if (status != SYNC_STATUS_OK) {
 664     SyncCompleted(token.Pass(), status);
 665     return;
 666   }
 667
 668   if (!entry) {
 669     NOTREACHED();
 670     SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 671     return;
 672   }
 673
 674   status = metadata_database()->ReplaceActiveTrackerWithNewResource(
 675       remote_parent_folder_tracker_->tracker_id(), *entry);
 676   SyncCompleted(token.Pass(), status);
 677 }
 678
 679 void LocalToRemoteSyncer::CreateRemoteFolder(scoped_ptr<SyncTaskToken> token) {
 680   DCHECK(remote_parent_folder_tracker_);
 681
 682   base::FilePath title = storage::VirtualPath::BaseName(target_path_);
 683   file_type_ = SYNC_FILE_TYPE_DIRECTORY;
 684   sync_action_ = SYNC_ACTION_ADDED;
 685
 686   DCHECK(!folder_creator_);
 687   folder_creator_.reset(new FolderCreator(
 688       drive_service(), metadata_database(),
 689       remote_parent_folder_tracker_->file_id(),
 690       title.AsUTF8Unsafe()));
 691   folder_creator_->Run(base::Bind(
 692       &LocalToRemoteSyncer::DidCreateRemoteFolder,
 693       weak_ptr_factory_.GetWeakPtr(),
 694       base::Passed(&token)));
 695 }
 696
 697 void LocalToRemoteSyncer::DidCreateRemoteFolder(
 698     scoped_ptr<SyncTaskToken> token,
 699     const std::string& file_id,
 700     SyncStatusCode status) {
 701   if (status == SYNC_FILE_ERROR_NOT_FOUND)
 702     needs_remote_change_listing_ = true;
 703
 704   scoped_ptr<FolderCreator> deleter = folder_creator_.Pass();
 705   if (status != SYNC_STATUS_OK) {
 706     SyncCompleted(token.Pass(), status);
 707     return;
 708   }
 709
 710   status = SYNC_STATUS_FAILED;
 711   MetadataDatabase::ActivationStatus activation_status =
 712       metadata_database()->TryActivateTracker(
 713           remote_parent_folder_tracker_->tracker_id(),
 714           file_id, &status);
 715   switch (activation_status) {
 716     case MetadataDatabase::ACTIVATION_PENDING:
 717       SyncCompleted(token.Pass(), status);
 718       return;
 719     case MetadataDatabase::ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER:
 720       // The activation failed due to another tracker that has another parent.
 721       // Detach the folder from the current parent to avoid using this folder as
 722       // active folder.
 723       drive_service()->RemoveResourceFromDirectory(
 724           remote_parent_folder_tracker_->file_id(), file_id,
 725           base::Bind(&LocalToRemoteSyncer::DidDetachResourceForCreationConflict,
 726                      weak_ptr_factory_.GetWeakPtr(), base::Passed(&token)));
 727       return;
 728   }
 729
 730   NOTREACHED();
 731   SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
 732   return;
 733 }
 734
 735 void LocalToRemoteSyncer::DidDetachResourceForCreationConflict(
 736     scoped_ptr<SyncTaskToken> token,
 737     google_apis::DriveApiErrorCode error) {
 738   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
 739   if (status != SYNC_STATUS_OK) {
 740     SyncCompleted(token.Pass(), status);
 741     return;
 742   }
 743
 744   SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 745 }
 746
 747 bool LocalToRemoteSyncer::IsContextReady() {
 748   return sync_context_->GetDriveService() &&
 749       sync_context_->GetDriveUploader() &&
 750       sync_context_->GetMetadataDatabase();
 751 }
 752
 753 drive::DriveServiceInterface* LocalToRemoteSyncer::drive_service() {
 754   set_used_network(true);
 755   return sync_context_->GetDriveService();
 756 }
 757
 758 drive::DriveUploaderInterface* LocalToRemoteSyncer::drive_uploader() {
 759   set_used_network(true);
 760   return sync_context_->GetDriveUploader();
 761 }
 762
 763 MetadataDatabase* LocalToRemoteSyncer::metadata_database() {
 764   return sync_context_->GetMetadataDatabase();
 765 }
 766
 767 }  // namespace drive_backend
 768 }  // namespace sync_file_system