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_METADATA_DATABASE_H_ 6 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_H_ 7 8 #include <map> 9 #include <set> 10 #include <string> 11 #include <vector> 12 13 #include "base/callback_forward.h" 14 #include "base/containers/hash_tables.h" 15 #include "base/containers/scoped_ptr_hash_map.h" 16 #include "base/memory/scoped_ptr.h" 17 #include "base/memory/scoped_vector.h" 18 #include "base/memory/weak_ptr.h" 19 #include "base/sequence_checker.h" 20 #include "base/values.h" 21 #include "chrome/browser/sync_file_system/drive_backend/tracker_id_set.h" 22 #include "chrome/browser/sync_file_system/sync_callbacks.h" 23 #include "chrome/browser/sync_file_system/sync_status_code.h" 24 25 namespace base { 26 class FilePath; 27 class SequencedTaskRunner; 28 class SingleThreadTaskRunner; 29 } 30 31 namespace leveldb { 32 class DB; 33 class Env; 34 class WriteBatch; 35 } 36 37 namespace google_apis { 38 class ChangeResource; 39 class FileResource; 40 class ResourceEntry; 41 } 42 43 namespace tracked_objects { 44 class Location; 45 } 46 47 namespace sync_file_system { 48 namespace drive_backend { 49 50 class FileDetails; 51 class FileMetadata; 52 class FileTracker; 53 class MetadataDatabaseIndexInterface; 54 class ServiceMetadata; 55 56 struct DatabaseContents { 57 scoped_ptr<ServiceMetadata> service_metadata; 58 ScopedVector<FileMetadata> file_metadata; 59 ScopedVector<FileTracker> file_trackers; 60 61 DatabaseContents(); 62 ~DatabaseContents(); 63 }; 64 65 // MetadataDatabase holds and maintains a LevelDB instance and its indexes, 66 // which holds 1)ServiceMetadata, 2)FileMetadata and 3)FileTracker. 67 // 1) ServiceMetadata is a singleton in the database which holds information for 68 // the backend. 69 // 2) FileMetadata represents a remote-side file and holds latest known 70 // metadata of the remote file. 71 // 3) FileTracker represents a synced or to-be-synced file and maintains 72 // the local-side folder tree. 73 // 74 // The term "file" includes files, folders and other resources on Drive. 75 // 76 // FileTrackers form a tree structure on the database, which represents the 77 // FileSystem trees of SyncFileSystem. The tree has a FileTracker named 78 // sync-root as its root node, and a set of FileTracker named app-root. An 79 // app-root represents a remote folder for an installed Chrome App and holds all 80 // synced contents for the App. 81 // 82 // One FileMetadata is created for each tracked remote file, which is identified 83 // by FileID. 84 // One FileTracker is created for every different {parent tracker, FileID} pair, 85 // excluding non-app-root inactive parent trackers. Multiple trackers may be 86 // associated to one FileID when the file has multiple parents. Multiple 87 // trackers may have the same {parent tracker, title} pair when the associated 88 // remote files have the same title. 89 // 90 // Files have following state: 91 // - Unknown file 92 // - Has a dirty inactive tracker and empty synced_details. 93 // - Is initial state of a tracker, only file_id and parent_tracker_id field 94 // are known. 95 // - Folder 96 // - Is either one of sync-root folder, app-root folder or a regular folder. 97 // - Sync-root folder holds app-root folders as its direct children, and 98 // holds entire SyncFileSystem files as its descentants. Its tracker 99 // should be stored in ServiceMetadata by its tracker_id. 100 // - App-root folder holds all files for an application as its descendants. 101 // - File 102 // - Unsupported file 103 // - Represents unsupported files such as hosted documents. Must be 104 // inactive. 105 // 106 // Invariants: 107 // - Any tracker in the database must either: 108 // - be sync-root, 109 // - have an app-root as its parent tracker, or 110 // - have an active tracker as its parent. 111 // That is, all trackers must be reachable from sync-root via app-root folders 112 // and active trackers. 113 // 114 // - Any active tracker must either: 115 // - have |needs_folder_listing| flag and dirty flag, or 116 // - have all children at the stored largest change ID. 117 // 118 // - If multiple trackers have the same parent tracker and same title, they 119 // must not have same |file_id|, and at most one of them may be active. 120 // - If multiple trackers have the same |file_id|, at most one of them may be 121 // active. 122 // 123 class MetadataDatabase { 124 public: 125 typedef std::vector<std::string> FileIDList; 126 127 typedef base::Callback< 128 void(SyncStatusCode status, scoped_ptr<MetadataDatabase> instance)> 129 CreateCallback; 130 131 enum ActivationStatus { 132 ACTIVATION_PENDING, 133 ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER, 134 }; 135 136 enum UpdateOption { 137 UPDATE_TRACKER_FOR_UNSYNCED_FILE, 138 UPDATE_TRACKER_FOR_SYNCED_FILE, 139 }; 140 141 // The entry point of the MetadataDatabase for production code. 142 // If |env_override| is non-NULL, internal LevelDB uses |env_override| instead 143 // of leveldb::Env::Default(). Use leveldb::MemEnv in test code for faster 144 // testing. 145 static void Create(base::SequencedTaskRunner* worker_task_runner, 146 base::SequencedTaskRunner* file_task_runner, 147 const base::FilePath& database_path, 148 leveldb::Env* env_override, 149 const CreateCallback& callback); 150 static SyncStatusCode CreateForTesting( 151 scoped_ptr<leveldb::DB> db, 152 scoped_ptr<MetadataDatabase>* metadata_database_out); 153 154 ~MetadataDatabase(); 155 156 static void ClearDatabase(scoped_ptr<MetadataDatabase> metadata_database); 157 158 int64 GetLargestFetchedChangeID() const; 159 int64 GetSyncRootTrackerID() const; 160 bool HasSyncRoot() const; 161 162 // Returns all file metadata for the given |app_id|. 163 scoped_ptr<base::ListValue> DumpFiles(const std::string& app_id); 164 165 // Returns all database data. 166 scoped_ptr<base::ListValue> DumpDatabase(); 167 168 // TODO(tzik): Move GetLargestKnownChangeID() to private section, and hide its 169 // handling in the class, instead of letting user do. 170 // 171 // Gets / updates the largest known change ID. 172 // The largest known change ID is on-memory and not persist over restart. 173 // This is supposed to use when a task fetches ChangeList in parallel to other 174 // operation. When a task starts fetching paged ChangeList one by one, it 175 // should update the largest known change ID on the first round and background 176 // remaining fetch job. 177 // Then, when other tasks that update FileMetadata by UpdateByFileResource, 178 // it should use largest known change ID as the |change_id| that prevents 179 // FileMetadata from overwritten by ChangeList. 180 // Also if other tasks try to update a remote resource whose change is not yet 181 // retrieved the task should fail due to etag check, so we should be fine. 182 int64 GetLargestKnownChangeID() const; 183 void UpdateLargestKnownChangeID(int64 change_id); 184 185 // Populates empty database with initial data. 186 // Adds a file metadata and a file tracker for |sync_root_folder|, and adds 187 // file metadata and file trackers for each |app_root_folders|. 188 // Newly added tracker for |sync_root_folder| is active and non-dirty. 189 // Newly added trackers for |app_root_folders| are inactive and non-dirty. 190 // Trackers for |app_root_folders| are not yet registered as app-roots, but 191 // are ready to register. 192 void PopulateInitialData( 193 int64 largest_change_id, 194 const google_apis::FileResource& sync_root_folder, 195 const ScopedVector<google_apis::FileResource>& app_root_folders, 196 const SyncStatusCallback& callback); 197 198 // Returns true if the folder associated to |app_id| is enabled. 199 bool IsAppEnabled(const std::string& app_id) const; 200 201 // Registers existing folder as the app-root for |app_id|. The folder 202 // must be an inactive folder that does not yet associated to any App. 203 // This method associates the folder with |app_id| and activates it. 204 void RegisterApp(const std::string& app_id, 205 const std::string& folder_id, 206 const SyncStatusCallback& callback); 207 208 // Inactivates the folder associated to the app to disable |app_id|. 209 // Does nothing if |app_id| is already disabled. 210 void DisableApp(const std::string& app_id, 211 const SyncStatusCallback& callback); 212 213 // Activates the folder associated to |app_id| to enable |app_id|. 214 // Does nothing if |app_id| is already enabled. 215 void EnableApp(const std::string& app_id, 216 const SyncStatusCallback& callback); 217 218 // Unregisters the folder as the app-root for |app_id|. If |app_id| does not 219 // exist, does nothing. The folder is left as an inactive regular folder. 220 // Note that the inactivation drops all descendant files since they are no 221 // longer reachable from sync-root via active folder or app-root. 222 void UnregisterApp(const std::string& app_id, 223 const SyncStatusCallback& callback); 224 225 // Finds the app-root folder for |app_id|. Returns true if exists. 226 // Copies the result to |tracker| if it is non-NULL. 227 bool FindAppRootTracker(const std::string& app_id, 228 FileTracker* tracker) const; 229 230 // Finds the file identified by |file_id|. Returns true if the file is found. 231 // Copies the metadata identified by |file_id| into |file| if exists and 232 // |file| is non-NULL. 233 bool FindFileByFileID(const std::string& file_id, FileMetadata* file) const; 234 235 // Finds the tracker identified by |tracker_id|. Returns true if the tracker 236 // is found. 237 // Copies the tracker identified by |tracker_id| into |tracker| if exists and 238 // |tracker| is non-NULL. 239 bool FindTrackerByTrackerID(int64 tracker_id, FileTracker* tracker) const; 240 241 // Finds the trackers tracking |file_id|. Returns true if the trackers are 242 // found. 243 bool FindTrackersByFileID(const std::string& file_id, 244 TrackerIDSet* trackers) const; 245 246 // Finds the set of trackers whose parent's tracker ID is |parent_tracker_id|, 247 // and who has |title| as its title in the synced_details. 248 // Copies the tracker set to |trackers| if it is non-NULL. 249 // Returns true if the trackers are found. 250 bool FindTrackersByParentAndTitle( 251 int64 parent_tracker_id, 252 const std::string& title, 253 TrackerIDSet* trackers) const; 254 255 // Builds the file path for the given tracker. Returns true on success. 256 // |path| can be NULL. 257 // The file path is relative to app-root and have a leading path separator. 258 bool BuildPathForTracker(int64 tracker_id, base::FilePath* path) const; 259 260 // Builds the file path for the given tracker for display purpose. 261 // This may return a path ending with '<unknown>' if the given tracker does 262 // not have title information (yet). This may return an empty path. 263 base::FilePath BuildDisplayPathForTracker(const FileTracker& tracker) const; 264 265 // Returns false if no registered app exists associated to |app_id|. 266 // If |full_path| is active, assigns the tracker of |full_path| to |tracker|. 267 // Otherwise, assigns the nearest active ancestor to |full_path| to |tracker|. 268 // Also, assigns the full path of |tracker| to |path|. 269 bool FindNearestActiveAncestor(const std::string& app_id, 270 const base::FilePath& full_path, 271 FileTracker* tracker, 272 base::FilePath* path) const; 273 274 // Updates database by |changes|. 275 // Marks each tracker for modified file as dirty and adds new trackers if 276 // needed. 277 void UpdateByChangeList(int64 largest_change_id, 278 ScopedVector<google_apis::ChangeResource> changes, 279 const SyncStatusCallback& callback); 280 281 // Updates database by |resource|. 282 // Marks each tracker for modified file as dirty and adds new trackers if 283 // needed. 284 void UpdateByFileResource(const google_apis::FileResource& resource, 285 const SyncStatusCallback& callback); 286 void UpdateByFileResourceList( 287 ScopedVector<google_apis::FileResource> resources, 288 const SyncStatusCallback& callback); 289 290 void UpdateByDeletedRemoteFile(const std::string& file_id, 291 const SyncStatusCallback& callback); 292 void UpdateByDeletedRemoteFileList(const FileIDList& file_ids, 293 const SyncStatusCallback& callback); 294 295 // Adds new FileTracker and FileMetadata. The database must not have 296 // |resource| beforehand. 297 // The newly added tracker under |parent_tracker_id| is active and non-dirty. 298 // Deactivates existing active tracker if exists that has the same title and 299 // parent_tracker to the newly added tracker. 300 void ReplaceActiveTrackerWithNewResource( 301 int64 parent_tracker_id, 302 const google_apis::FileResource& resource, 303 const SyncStatusCallback& callback); 304 305 // Adds |child_file_ids| to |folder_id| as its children. 306 // This method affects the active tracker only. 307 // If the tracker has no further change to sync, unmarks its dirty flag. 308 void PopulateFolderByChildList(const std::string& folder_id, 309 const FileIDList& child_file_ids, 310 const SyncStatusCallback& callback); 311 312 // Updates |synced_details| of the tracker with |updated_details|. 313 void UpdateTracker(int64 tracker_id, 314 const FileDetails& updated_details, 315 const SyncStatusCallback& callback); 316 317 // Activates a tracker identified by |parent_tracker_id| and |file_id| if the 318 // tracker can be activated without inactivating other trackers that have the 319 // same |file_id| but different paths. 320 // If |file_id| has another active tracker, the function returns 321 // ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER and does not invoke |callback|. 322 // If there is another active tracker that has the same path but different 323 // |file_id|, inactivates the tracker. 324 // In success case, returns ACTIVATION_PENDING and invokes |callback| upon 325 // completion. 326 // 327 // The tracker to be activated must: 328 // - have a tracked metadata in the database, 329 // - have |synced_details| with valid |title|. 330 ActivationStatus TryActivateTracker(int64 parent_tracker_id, 331 const std::string& file_id, 332 const SyncStatusCallback& callback); 333 334 // Changes the priority of the tracker to low. 335 void LowerTrackerPriority(int64 tracker_id); 336 void PromoteLowerPriorityTrackersToNormal(); 337 338 // Returns true if there is a normal priority dirty tracker. 339 // Assigns the dirty tracker if exists and |tracker| is non-NULL. 340 bool GetNormalPriorityDirtyTracker(FileTracker* tracker) const; 341 342 // Returns true if there is a low priority dirty tracker. 343 bool HasLowPriorityDirtyTracker() const; 344 345 bool HasDirtyTracker() const; 346 size_t CountDirtyTracker() const; 347 size_t CountFileMetadata() const; 348 size_t CountFileTracker() const; 349 350 bool GetMultiParentFileTrackers(std::string* file_id, 351 TrackerIDSet* trackers); 352 bool GetConflictingTrackers(TrackerIDSet* trackers); 353 354 // Sets |app_ids| to a list of all registered app ids. 355 void GetRegisteredAppIDs(std::vector<std::string>* app_ids); 356 357 private: 358 friend class MetadataDatabaseTest; 359 struct CreateParam; 360 361 MetadataDatabase(base::SequencedTaskRunner* worker_task_runner, 362 base::SequencedTaskRunner* file_task_runner, 363 const base::FilePath& database_path, 364 leveldb::Env* env_override); 365 static void CreateOnFileTaskRunner( 366 scoped_ptr<CreateParam> create_param, 367 const CreateCallback& callback); 368 SyncStatusCode InitializeOnFileTaskRunner(); 369 void BuildIndexes(DatabaseContents* contents); 370 371 // Database manipulation methods. 372 void RegisterTrackerAsAppRoot(const std::string& app_id, 373 int64 tracker_id, 374 leveldb::WriteBatch* batch); 375 376 void CreateTrackerForParentAndFileID(const FileTracker& parent_tracker, 377 const std::string& file_id, 378 leveldb::WriteBatch* batch); 379 void CreateTrackerForParentAndFileMetadata(const FileTracker& parent_tracker, 380 const FileMetadata& file_metadata, 381 UpdateOption option, 382 leveldb::WriteBatch* batch); 383 void CreateTrackerInternal(const FileTracker& parent_tracker, 384 const std::string& file_id, 385 const FileDetails* details, 386 UpdateOption option, 387 leveldb::WriteBatch* batch); 388 389 void MaybeAddTrackersForNewFile(const FileMetadata& file, 390 UpdateOption option, 391 leveldb::WriteBatch* batch); 392 393 int64 IncrementTrackerID(leveldb::WriteBatch* batch); 394 395 bool CanActivateTracker(const FileTracker& tracker); 396 bool ShouldKeepDirty(const FileTracker& tracker) const; 397 398 bool HasDisabledAppRoot(const FileTracker& tracker) const; 399 bool HasActiveTrackerForFileID(const std::string& file_id) const; 400 bool HasActiveTrackerForPath(int64 parent_tracker, 401 const std::string& title) const; 402 403 void RemoveUnneededTrackersForMissingFile(const std::string& file_id, 404 leveldb::WriteBatch* batch); 405 void UpdateByFileMetadata(const tracked_objects::Location& from_where, 406 scoped_ptr<FileMetadata> file, 407 UpdateOption option, 408 leveldb::WriteBatch* batch); 409 410 void WriteToDatabase(scoped_ptr<leveldb::WriteBatch> batch, 411 const SyncStatusCallback& callback); 412 413 bool HasNewerFileMetadata(const std::string& file_id, int64 change_id); 414 415 scoped_ptr<base::ListValue> DumpTrackers(); 416 scoped_ptr<base::ListValue> DumpMetadata(); 417 418 void AttachSyncRoot(const google_apis::FileResource& sync_root_folder, 419 leveldb::WriteBatch* batch); 420 void AttachInitialAppRoot(const google_apis::FileResource& app_root_folder, 421 leveldb::WriteBatch* batch); 422 423 void ForceActivateTrackerByPath(int64 parent_tracker_id, 424 const std::string& title, 425 const std::string& file_id, 426 leveldb::WriteBatch* batch); 427 428 void DetachFromSequence(); 429 430 scoped_refptr<base::SequencedTaskRunner> worker_task_runner_; 431 scoped_refptr<base::SequencedTaskRunner> file_task_runner_; 432 base::FilePath database_path_; 433 leveldb::Env* env_override_; 434 scoped_ptr<leveldb::DB> db_; 435 436 scoped_ptr<ServiceMetadata> service_metadata_; 437 int64 largest_known_change_id_; 438 439 scoped_ptr<MetadataDatabaseIndexInterface> index_; 440 441 base::WeakPtrFactory<MetadataDatabase> weak_ptr_factory_; 442 443 base::SequenceChecker worker_sequence_checker_; 444 445 DISALLOW_COPY_AND_ASSIGN(MetadataDatabase); 446 }; 447 448 } // namespace drive_backend 449 } // namespace sync_file_system 450 451 #endif // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_H_ 452