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| 1 // Copyright (c) 2012 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 "webkit/browser/dom_storage/session_storage_database.h" | |
| 6 | |
| 7 #include "base/file_util.h" | |
| 8 #include "base/logging.h" | |
| 9 #include "base/metrics/histogram.h" | |
| 10 #include "base/strings/string_number_conversions.h" | |
| 11 #include "base/strings/stringprintf.h" | |
| 12 #include "base/strings/utf_string_conversions.h" | |
| 13 #include "third_party/leveldatabase/src/include/leveldb/db.h" | |
| 14 #include "third_party/leveldatabase/src/include/leveldb/iterator.h" | |
| 15 #include "third_party/leveldatabase/src/include/leveldb/options.h" | |
| 16 #include "third_party/leveldatabase/src/include/leveldb/status.h" | |
| 17 #include "third_party/leveldatabase/src/include/leveldb/write_batch.h" | |
| 18 #include "url/gurl.h" | |
| 19 | |
| 20 | |
| 21 namespace { | |
| 22 | |
| 23 const char session_storage_uma_name[] = "SessionStorageDatabase.Open"; | |
| 24 | |
| 25 enum SessionStorageUMA { | |
| 26 SESSION_STORAGE_UMA_SUCCESS, | |
| 27 SESSION_STORAGE_UMA_RECREATED, | |
| 28 SESSION_STORAGE_UMA_FAIL, | |
| 29 SESSION_STORAGE_UMA_MAX | |
| 30 }; | |
| 31 | |
| 32 } // namespace | |
| 33 | |
| 34 // Layout of the database: | |
| 35 // | key | value | | |
| 36 // ----------------------------------------------------------------------- | |
| 37 // | map-1- | 2 (refcount, start of map-1-* keys)| | |
| 38 // | map-1-a | b (a = b in map 1) | | |
| 39 // | ... | | | |
| 40 // | namespace- | dummy (start of namespace-* keys) | | |
| 41 // | namespace-1- (1 = namespace id)| dummy (start of namespace-1-* keys)| | |
| 42 // | namespace-1-origin1 | 1 (mapid) | | |
| 43 // | namespace-1-origin2 | 2 | | |
| 44 // | namespace-2- | dummy | | |
| 45 // | namespace-2-origin1 | 1 (shallow copy) | | |
| 46 // | namespace-2-origin2 | 2 (shallow copy) | | |
| 47 // | namespace-3- | dummy | | |
| 48 // | namespace-3-origin1 | 3 (deep copy) | | |
| 49 // | namespace-3-origin2 | 2 (shallow copy) | | |
| 50 // | next-map-id | 4 | | |
| 51 | |
| 52 namespace dom_storage { | |
| 53 | |
| 54 SessionStorageDatabase::SessionStorageDatabase(const base::FilePath& file_path) | |
| 55 : file_path_(file_path), | |
| 56 db_error_(false), | |
| 57 is_inconsistent_(false) { | |
| 58 } | |
| 59 | |
| 60 SessionStorageDatabase::~SessionStorageDatabase() { | |
| 61 } | |
| 62 | |
| 63 void SessionStorageDatabase::ReadAreaValues(const std::string& namespace_id, | |
| 64 const GURL& origin, | |
| 65 ValuesMap* result) { | |
| 66 // We don't create a database if it doesn't exist. In that case, there is | |
| 67 // nothing to be added to the result. | |
| 68 if (!LazyOpen(false)) | |
| 69 return; | |
| 70 | |
| 71 // While ReadAreaValues is in progress, another thread can call | |
| 72 // CommitAreaChanges. CommitAreaChanges might update map ref count key while | |
| 73 // this thread is iterating over the map ref count key. To protect the reading | |
| 74 // operation, create a snapshot and read from it. | |
| 75 leveldb::ReadOptions options; | |
| 76 options.snapshot = db_->GetSnapshot(); | |
| 77 | |
| 78 std::string map_id; | |
| 79 bool exists; | |
| 80 if (GetMapForArea(namespace_id, origin.spec(), options, &exists, &map_id) && | |
| 81 exists) | |
| 82 ReadMap(map_id, options, result, false); | |
| 83 db_->ReleaseSnapshot(options.snapshot); | |
| 84 } | |
| 85 | |
| 86 bool SessionStorageDatabase::CommitAreaChanges(const std::string& namespace_id, | |
| 87 const GURL& origin, | |
| 88 bool clear_all_first, | |
| 89 const ValuesMap& changes) { | |
| 90 // Even if |changes| is empty, we need to write the appropriate placeholders | |
| 91 // in the database, so that it can be later shallow-copied succssfully. | |
| 92 if (!LazyOpen(true)) | |
| 93 return false; | |
| 94 | |
| 95 leveldb::WriteBatch batch; | |
| 96 // Ensure that the keys "namespace-" "namespace-N" (see the schema above) | |
| 97 // exist. | |
| 98 const bool kOkIfExists = true; | |
| 99 if (!CreateNamespace(namespace_id, kOkIfExists, &batch)) | |
| 100 return false; | |
| 101 | |
| 102 std::string map_id; | |
| 103 bool exists; | |
| 104 if (!GetMapForArea(namespace_id, origin.spec(), leveldb::ReadOptions(), | |
| 105 &exists, &map_id)) | |
| 106 return false; | |
| 107 if (exists) { | |
| 108 int64 ref_count; | |
| 109 if (!GetMapRefCount(map_id, &ref_count)) | |
| 110 return false; | |
| 111 if (ref_count > 1) { | |
| 112 if (!DeepCopyArea(namespace_id, origin, !clear_all_first, | |
| 113 &map_id, &batch)) | |
| 114 return false; | |
| 115 } | |
| 116 else if (clear_all_first) { | |
| 117 if (!ClearMap(map_id, &batch)) | |
| 118 return false; | |
| 119 } | |
| 120 } else { | |
| 121 // Map doesn't exist, create it now if needed. | |
| 122 if (!changes.empty()) { | |
| 123 if (!CreateMapForArea(namespace_id, origin, &map_id, &batch)) | |
| 124 return false; | |
| 125 } | |
| 126 } | |
| 127 | |
| 128 WriteValuesToMap(map_id, changes, &batch); | |
| 129 | |
| 130 leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); | |
| 131 return DatabaseErrorCheck(s.ok()); | |
| 132 } | |
| 133 | |
| 134 bool SessionStorageDatabase::CloneNamespace( | |
| 135 const std::string& namespace_id, const std::string& new_namespace_id) { | |
| 136 // Go through all origins in the namespace |namespace_id|, create placeholders | |
| 137 // for them in |new_namespace_id|, and associate them with the existing maps. | |
| 138 | |
| 139 // Example, data before shallow copy: | |
| 140 // | map-1- | 1 (refcount) | | |
| 141 // | map-1-a | b | | |
| 142 // | namespace-1- (1 = namespace id)| dummy | | |
| 143 // | namespace-1-origin1 | 1 (mapid) | | |
| 144 | |
| 145 // Example, data after shallow copy: | |
| 146 // | map-1- | 2 (inc. refcount) | | |
| 147 // | map-1-a | b | | |
| 148 // | namespace-1-(1 = namespace id) | dummy | | |
| 149 // | namespace-1-origin1 | 1 (mapid) | | |
| 150 // | namespace-2- | dummy | | |
| 151 // | namespace-2-origin1 | 1 (mapid) << references the same map | |
| 152 | |
| 153 if (!LazyOpen(true)) | |
| 154 return false; | |
| 155 | |
| 156 leveldb::WriteBatch batch; | |
| 157 const bool kOkIfExists = false; | |
| 158 if (!CreateNamespace(new_namespace_id, kOkIfExists, &batch)) | |
| 159 return false; | |
| 160 | |
| 161 std::map<std::string, std::string> areas; | |
| 162 if (!GetAreasInNamespace(namespace_id, &areas)) | |
| 163 return false; | |
| 164 | |
| 165 for (std::map<std::string, std::string>::const_iterator it = areas.begin(); | |
| 166 it != areas.end(); ++it) { | |
| 167 const std::string& origin = it->first; | |
| 168 const std::string& map_id = it->second; | |
| 169 if (!IncreaseMapRefCount(map_id, &batch)) | |
| 170 return false; | |
| 171 AddAreaToNamespace(new_namespace_id, origin, map_id, &batch); | |
| 172 } | |
| 173 leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); | |
| 174 return DatabaseErrorCheck(s.ok()); | |
| 175 } | |
| 176 | |
| 177 bool SessionStorageDatabase::DeleteArea(const std::string& namespace_id, | |
| 178 const GURL& origin) { | |
| 179 if (!LazyOpen(false)) { | |
| 180 // No need to create the database if it doesn't exist. | |
| 181 return true; | |
| 182 } | |
| 183 leveldb::WriteBatch batch; | |
| 184 if (!DeleteAreaHelper(namespace_id, origin.spec(), &batch)) | |
| 185 return false; | |
| 186 leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); | |
| 187 return DatabaseErrorCheck(s.ok()); | |
| 188 } | |
| 189 | |
| 190 bool SessionStorageDatabase::DeleteNamespace(const std::string& namespace_id) { | |
| 191 if (!LazyOpen(false)) { | |
| 192 // No need to create the database if it doesn't exist. | |
| 193 return true; | |
| 194 } | |
| 195 // Itereate through the areas in the namespace. | |
| 196 leveldb::WriteBatch batch; | |
| 197 std::map<std::string, std::string> areas; | |
| 198 if (!GetAreasInNamespace(namespace_id, &areas)) | |
| 199 return false; | |
| 200 for (std::map<std::string, std::string>::const_iterator it = areas.begin(); | |
| 201 it != areas.end(); ++it) { | |
| 202 const std::string& origin = it->first; | |
| 203 if (!DeleteAreaHelper(namespace_id, origin, &batch)) | |
| 204 return false; | |
| 205 } | |
| 206 batch.Delete(NamespaceStartKey(namespace_id)); | |
| 207 leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); | |
| 208 return DatabaseErrorCheck(s.ok()); | |
| 209 } | |
| 210 | |
| 211 bool SessionStorageDatabase::ReadNamespacesAndOrigins( | |
| 212 std::map<std::string, std::vector<GURL> >* namespaces_and_origins) { | |
| 213 if (!LazyOpen(true)) | |
| 214 return false; | |
| 215 | |
| 216 // While ReadNamespacesAndOrigins is in progress, another thread can call | |
| 217 // CommitAreaChanges. To protect the reading operation, create a snapshot and | |
| 218 // read from it. | |
| 219 leveldb::ReadOptions options; | |
| 220 options.snapshot = db_->GetSnapshot(); | |
| 221 | |
| 222 std::string namespace_prefix = NamespacePrefix(); | |
| 223 scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); | |
| 224 it->Seek(namespace_prefix); | |
| 225 // If the key is not found, the status of the iterator won't be IsNotFound(), | |
| 226 // but the iterator will be invalid. | |
| 227 if (!it->Valid()) { | |
| 228 db_->ReleaseSnapshot(options.snapshot); | |
| 229 return true; | |
| 230 } | |
| 231 | |
| 232 if (!DatabaseErrorCheck(it->status().ok())) { | |
| 233 db_->ReleaseSnapshot(options.snapshot); | |
| 234 return false; | |
| 235 } | |
| 236 | |
| 237 // Skip the dummy entry "namespace-" and iterate the namespaces. | |
| 238 std::string current_namespace_start_key; | |
| 239 std::string current_namespace_id; | |
| 240 for (it->Next(); it->Valid(); it->Next()) { | |
| 241 std::string key = it->key().ToString(); | |
| 242 if (key.find(namespace_prefix) != 0) { | |
| 243 // Iterated past the "namespace-" keys. | |
| 244 break; | |
| 245 } | |
| 246 // For each namespace, the first key is "namespace-<namespaceid>-", and the | |
| 247 // subsequent keys are "namespace-<namespaceid>-<origin>". Read the unique | |
| 248 // "<namespaceid>" parts from the keys. | |
| 249 if (current_namespace_start_key.empty() || | |
| 250 key.substr(0, current_namespace_start_key.length()) != | |
| 251 current_namespace_start_key) { | |
| 252 // The key is of the form "namespace-<namespaceid>-" for a new | |
| 253 // <namespaceid>. | |
| 254 current_namespace_start_key = key; | |
| 255 current_namespace_id = | |
| 256 key.substr(namespace_prefix.length(), | |
| 257 key.length() - namespace_prefix.length() - 1); | |
| 258 // Ensure that we keep track of the namespace even if it doesn't contain | |
| 259 // any origins. | |
| 260 namespaces_and_origins->insert( | |
| 261 std::make_pair(current_namespace_id, std::vector<GURL>())); | |
| 262 } else { | |
| 263 // The key is of the form "namespace-<namespaceid>-<origin>". | |
| 264 std::string origin = key.substr(current_namespace_start_key.length()); | |
| 265 (*namespaces_and_origins)[current_namespace_id].push_back(GURL(origin)); | |
| 266 } | |
| 267 } | |
| 268 db_->ReleaseSnapshot(options.snapshot); | |
| 269 return true; | |
| 270 } | |
| 271 | |
| 272 bool SessionStorageDatabase::LazyOpen(bool create_if_needed) { | |
| 273 base::AutoLock auto_lock(db_lock_); | |
| 274 if (db_error_ || is_inconsistent_) { | |
| 275 // Don't try to open a database that we know has failed already. | |
| 276 return false; | |
| 277 } | |
| 278 if (IsOpen()) | |
| 279 return true; | |
| 280 | |
| 281 if (!create_if_needed && | |
| 282 (!base::PathExists(file_path_) || | |
| 283 file_util::IsDirectoryEmpty(file_path_))) { | |
| 284 // If the directory doesn't exist already and we haven't been asked to | |
| 285 // create a file on disk, then we don't bother opening the database. This | |
| 286 // means we wait until we absolutely need to put something onto disk before | |
| 287 // we do so. | |
| 288 return false; | |
| 289 } | |
| 290 | |
| 291 leveldb::DB* db; | |
| 292 leveldb::Status s = TryToOpen(&db); | |
| 293 if (!s.ok()) { | |
| 294 LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() | |
| 295 << ", error: " << s.ToString(); | |
| 296 DCHECK(db == NULL); | |
| 297 | |
| 298 // Clear the directory and try again. | |
| 299 base::DeleteFile(file_path_, true); | |
| 300 s = TryToOpen(&db); | |
| 301 if (!s.ok()) { | |
| 302 LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() | |
| 303 << ", error: " << s.ToString(); | |
| 304 UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, | |
| 305 SESSION_STORAGE_UMA_FAIL, | |
| 306 SESSION_STORAGE_UMA_MAX); | |
| 307 DCHECK(db == NULL); | |
| 308 db_error_ = true; | |
| 309 return false; | |
| 310 } | |
| 311 UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, | |
| 312 SESSION_STORAGE_UMA_RECREATED, | |
| 313 SESSION_STORAGE_UMA_MAX); | |
| 314 } else { | |
| 315 UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, | |
| 316 SESSION_STORAGE_UMA_SUCCESS, | |
| 317 SESSION_STORAGE_UMA_MAX); | |
| 318 } | |
| 319 db_.reset(db); | |
| 320 return true; | |
| 321 } | |
| 322 | |
| 323 leveldb::Status SessionStorageDatabase::TryToOpen(leveldb::DB** db) { | |
| 324 leveldb::Options options; | |
| 325 // The directory exists but a valid leveldb database might not exist inside it | |
| 326 // (e.g., a subset of the needed files might be missing). Handle this | |
| 327 // situation gracefully by creating the database now. | |
| 328 options.max_open_files = 0; // Use minimum. | |
| 329 options.create_if_missing = true; | |
| 330 #if defined(OS_WIN) | |
| 331 return leveldb::DB::Open(options, WideToUTF8(file_path_.value()), db); | |
| 332 #elif defined(OS_POSIX) | |
| 333 return leveldb::DB::Open(options, file_path_.value(), db); | |
| 334 #endif | |
| 335 } | |
| 336 | |
| 337 bool SessionStorageDatabase::IsOpen() const { | |
| 338 return db_.get() != NULL; | |
| 339 } | |
| 340 | |
| 341 bool SessionStorageDatabase::CallerErrorCheck(bool ok) const { | |
| 342 DCHECK(ok); | |
| 343 return ok; | |
| 344 } | |
| 345 | |
| 346 bool SessionStorageDatabase::ConsistencyCheck(bool ok) { | |
| 347 if (ok) | |
| 348 return true; | |
| 349 base::AutoLock auto_lock(db_lock_); | |
| 350 DCHECK(false); | |
| 351 is_inconsistent_ = true; | |
| 352 // We cannot recover the database during this run, e.g., the upper layer can | |
| 353 // have a different understanding of the database state (shallow and deep | |
| 354 // copies). | |
| 355 // TODO(marja): Error handling. | |
| 356 return false; | |
| 357 } | |
| 358 | |
| 359 bool SessionStorageDatabase::DatabaseErrorCheck(bool ok) { | |
| 360 if (ok) | |
| 361 return true; | |
| 362 base::AutoLock auto_lock(db_lock_); | |
| 363 db_error_ = true; | |
| 364 // TODO(marja): Error handling. | |
| 365 return false; | |
| 366 } | |
| 367 | |
| 368 bool SessionStorageDatabase::CreateNamespace(const std::string& namespace_id, | |
| 369 bool ok_if_exists, | |
| 370 leveldb::WriteBatch* batch) { | |
| 371 leveldb::Slice namespace_prefix = NamespacePrefix(); | |
| 372 std::string dummy; | |
| 373 leveldb::Status s = db_->Get(leveldb::ReadOptions(), namespace_prefix, | |
| 374 &dummy); | |
| 375 if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) | |
| 376 return false; | |
| 377 if (s.IsNotFound()) | |
| 378 batch->Put(namespace_prefix, ""); | |
| 379 | |
| 380 std::string namespace_start_key = NamespaceStartKey(namespace_id); | |
| 381 s = db_->Get(leveldb::ReadOptions(), namespace_start_key, &dummy); | |
| 382 if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) | |
| 383 return false; | |
| 384 if (s.IsNotFound()) { | |
| 385 batch->Put(namespace_start_key, ""); | |
| 386 return true; | |
| 387 } | |
| 388 return CallerErrorCheck(ok_if_exists); | |
| 389 } | |
| 390 | |
| 391 bool SessionStorageDatabase::GetAreasInNamespace( | |
| 392 const std::string& namespace_id, | |
| 393 std::map<std::string, std::string>* areas) { | |
| 394 std::string namespace_start_key = NamespaceStartKey(namespace_id); | |
| 395 scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); | |
| 396 it->Seek(namespace_start_key); | |
| 397 // If the key is not found, the status of the iterator won't be IsNotFound(), | |
| 398 // but the iterator will be invalid. | |
| 399 if (!it->Valid()) { | |
| 400 // The namespace_start_key is not found when the namespace doesn't contain | |
| 401 // any areas. We don't need to do anything. | |
| 402 return true; | |
| 403 } | |
| 404 if (!DatabaseErrorCheck(it->status().ok())) | |
| 405 return false; | |
| 406 | |
| 407 // Skip the dummy entry "namespace-<namespaceid>-" and iterate the origins. | |
| 408 for (it->Next(); it->Valid(); it->Next()) { | |
| 409 std::string key = it->key().ToString(); | |
| 410 if (key.find(namespace_start_key) != 0) { | |
| 411 // Iterated past the origins for this namespace. | |
| 412 break; | |
| 413 } | |
| 414 std::string origin = key.substr(namespace_start_key.length()); | |
| 415 std::string map_id = it->value().ToString(); | |
| 416 (*areas)[origin] = map_id; | |
| 417 } | |
| 418 return true; | |
| 419 } | |
| 420 | |
| 421 void SessionStorageDatabase::AddAreaToNamespace(const std::string& namespace_id, | |
| 422 const std::string& origin, | |
| 423 const std::string& map_id, | |
| 424 leveldb::WriteBatch* batch) { | |
| 425 std::string namespace_key = NamespaceKey(namespace_id, origin); | |
| 426 batch->Put(namespace_key, map_id); | |
| 427 } | |
| 428 | |
| 429 bool SessionStorageDatabase::DeleteAreaHelper( | |
| 430 const std::string& namespace_id, | |
| 431 const std::string& origin, | |
| 432 leveldb::WriteBatch* batch) { | |
| 433 std::string map_id; | |
| 434 bool exists; | |
| 435 if (!GetMapForArea(namespace_id, origin, leveldb::ReadOptions(), &exists, | |
| 436 &map_id)) | |
| 437 return false; | |
| 438 if (!exists) | |
| 439 return true; // Nothing to delete. | |
| 440 if (!DecreaseMapRefCount(map_id, 1, batch)) | |
| 441 return false; | |
| 442 std::string namespace_key = NamespaceKey(namespace_id, origin); | |
| 443 batch->Delete(namespace_key); | |
| 444 | |
| 445 // If this was the only area in the namespace, delete the namespace start key, | |
| 446 // too. | |
| 447 std::string namespace_start_key = NamespaceStartKey(namespace_id); | |
| 448 scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); | |
| 449 it->Seek(namespace_start_key); | |
| 450 if (!ConsistencyCheck(it->Valid())) | |
| 451 return false; | |
| 452 // Advance the iterator 2 times (we still haven't really deleted | |
| 453 // namespace_key). | |
| 454 it->Next(); | |
| 455 if (!ConsistencyCheck(it->Valid())) | |
| 456 return false; | |
| 457 it->Next(); | |
| 458 if (!it->Valid()) | |
| 459 return true; | |
| 460 std::string key = it->key().ToString(); | |
| 461 if (key.find(namespace_start_key) != 0) | |
| 462 batch->Delete(namespace_start_key); | |
| 463 return true; | |
| 464 } | |
| 465 | |
| 466 bool SessionStorageDatabase::GetMapForArea(const std::string& namespace_id, | |
| 467 const std::string& origin, | |
| 468 const leveldb::ReadOptions& options, | |
| 469 bool* exists, std::string* map_id) { | |
| 470 std::string namespace_key = NamespaceKey(namespace_id, origin); | |
| 471 leveldb::Status s = db_->Get(options, namespace_key, map_id); | |
| 472 if (s.IsNotFound()) { | |
| 473 *exists = false; | |
| 474 return true; | |
| 475 } | |
| 476 *exists = true; | |
| 477 return DatabaseErrorCheck(s.ok()); | |
| 478 } | |
| 479 | |
| 480 bool SessionStorageDatabase::CreateMapForArea(const std::string& namespace_id, | |
| 481 const GURL& origin, | |
| 482 std::string* map_id, | |
| 483 leveldb::WriteBatch* batch) { | |
| 484 leveldb::Slice next_map_id_key = NextMapIdKey(); | |
| 485 leveldb::Status s = db_->Get(leveldb::ReadOptions(), next_map_id_key, map_id); | |
| 486 if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) | |
| 487 return false; | |
| 488 int64 next_map_id = 0; | |
| 489 if (s.IsNotFound()) { | |
| 490 *map_id = "0"; | |
| 491 } else { | |
| 492 bool conversion_ok = base::StringToInt64(*map_id, &next_map_id); | |
| 493 if (!ConsistencyCheck(conversion_ok)) | |
| 494 return false; | |
| 495 } | |
| 496 batch->Put(next_map_id_key, base::Int64ToString(++next_map_id)); | |
| 497 std::string namespace_key = NamespaceKey(namespace_id, origin.spec()); | |
| 498 batch->Put(namespace_key, *map_id); | |
| 499 batch->Put(MapRefCountKey(*map_id), "1"); | |
| 500 return true; | |
| 501 } | |
| 502 | |
| 503 bool SessionStorageDatabase::ReadMap(const std::string& map_id, | |
| 504 const leveldb::ReadOptions& options, | |
| 505 ValuesMap* result, | |
| 506 bool only_keys) { | |
| 507 scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); | |
| 508 std::string map_start_key = MapRefCountKey(map_id); | |
| 509 it->Seek(map_start_key); | |
| 510 // If the key is not found, the status of the iterator won't be IsNotFound(), | |
| 511 // but the iterator will be invalid. The map needs to exist, otherwise we have | |
| 512 // a stale map_id in the database. | |
| 513 if (!ConsistencyCheck(it->Valid())) | |
| 514 return false; | |
| 515 if (!DatabaseErrorCheck(it->status().ok())) | |
| 516 return false; | |
| 517 // Skip the dummy entry "map-<mapid>-". | |
| 518 for (it->Next(); it->Valid(); it->Next()) { | |
| 519 std::string key = it->key().ToString(); | |
| 520 if (key.find(map_start_key) != 0) { | |
| 521 // Iterated past the keys in this map. | |
| 522 break; | |
| 523 } | |
| 524 // Key is of the form "map-<mapid>-<key>". | |
| 525 base::string16 key16 = UTF8ToUTF16(key.substr(map_start_key.length())); | |
| 526 if (only_keys) { | |
| 527 (*result)[key16] = base::NullableString16(); | |
| 528 } else { | |
| 529 // Convert the raw data stored in std::string (it->value()) to raw data | |
| 530 // stored in base::string16. | |
| 531 size_t len = it->value().size() / sizeof(char16); | |
| 532 const char16* data_ptr = | |
| 533 reinterpret_cast<const char16*>(it->value().data()); | |
| 534 (*result)[key16] = | |
| 535 base::NullableString16(base::string16(data_ptr, len), false); | |
| 536 } | |
| 537 } | |
| 538 return true; | |
| 539 } | |
| 540 | |
| 541 void SessionStorageDatabase::WriteValuesToMap(const std::string& map_id, | |
| 542 const ValuesMap& values, | |
| 543 leveldb::WriteBatch* batch) { | |
| 544 for (ValuesMap::const_iterator it = values.begin(); it != values.end(); | |
| 545 ++it) { | |
| 546 base::NullableString16 value = it->second; | |
| 547 std::string key = MapKey(map_id, UTF16ToUTF8(it->first)); | |
| 548 if (value.is_null()) { | |
| 549 batch->Delete(key); | |
| 550 } else { | |
| 551 // Convert the raw data stored in base::string16 to raw data stored in | |
| 552 // std::string. | |
| 553 const char* data = reinterpret_cast<const char*>(value.string().data()); | |
| 554 size_t size = value.string().size() * 2; | |
| 555 batch->Put(key, leveldb::Slice(data, size)); | |
| 556 } | |
| 557 } | |
| 558 } | |
| 559 | |
| 560 bool SessionStorageDatabase::GetMapRefCount(const std::string& map_id, | |
| 561 int64* ref_count) { | |
| 562 std::string ref_count_string; | |
| 563 leveldb::Status s = db_->Get(leveldb::ReadOptions(), | |
| 564 MapRefCountKey(map_id), &ref_count_string); | |
| 565 if (!ConsistencyCheck(s.ok())) | |
| 566 return false; | |
| 567 bool conversion_ok = base::StringToInt64(ref_count_string, ref_count); | |
| 568 return ConsistencyCheck(conversion_ok); | |
| 569 } | |
| 570 | |
| 571 bool SessionStorageDatabase::IncreaseMapRefCount(const std::string& map_id, | |
| 572 leveldb::WriteBatch* batch) { | |
| 573 // Increase the ref count for the map. | |
| 574 int64 old_ref_count; | |
| 575 if (!GetMapRefCount(map_id, &old_ref_count)) | |
| 576 return false; | |
| 577 batch->Put(MapRefCountKey(map_id), base::Int64ToString(++old_ref_count)); | |
| 578 return true; | |
| 579 } | |
| 580 | |
| 581 bool SessionStorageDatabase::DecreaseMapRefCount(const std::string& map_id, | |
| 582 int decrease, | |
| 583 leveldb::WriteBatch* batch) { | |
| 584 // Decrease the ref count for the map. | |
| 585 int64 ref_count; | |
| 586 if (!GetMapRefCount(map_id, &ref_count)) | |
| 587 return false; | |
| 588 if (!ConsistencyCheck(decrease <= ref_count)) | |
| 589 return false; | |
| 590 ref_count -= decrease; | |
| 591 if (ref_count > 0) { | |
| 592 batch->Put(MapRefCountKey(map_id), base::Int64ToString(ref_count)); | |
| 593 } else { | |
| 594 // Clear all keys in the map. | |
| 595 if (!ClearMap(map_id, batch)) | |
| 596 return false; | |
| 597 batch->Delete(MapRefCountKey(map_id)); | |
| 598 } | |
| 599 return true; | |
| 600 } | |
| 601 | |
| 602 bool SessionStorageDatabase::ClearMap(const std::string& map_id, | |
| 603 leveldb::WriteBatch* batch) { | |
| 604 ValuesMap values; | |
| 605 if (!ReadMap(map_id, leveldb::ReadOptions(), &values, true)) | |
| 606 return false; | |
| 607 for (ValuesMap::const_iterator it = values.begin(); it != values.end(); ++it) | |
| 608 batch->Delete(MapKey(map_id, UTF16ToUTF8(it->first))); | |
| 609 return true; | |
| 610 } | |
| 611 | |
| 612 bool SessionStorageDatabase::DeepCopyArea( | |
| 613 const std::string& namespace_id, const GURL& origin, bool copy_data, | |
| 614 std::string* map_id, leveldb::WriteBatch* batch) { | |
| 615 // Example, data before deep copy: | |
| 616 // | namespace-1- (1 = namespace id)| dummy | | |
| 617 // | namespace-1-origin1 | 1 (mapid) | | |
| 618 // | namespace-2- | dummy | | |
| 619 // | namespace-2-origin1 | 1 (mapid) << references the same map | |
| 620 // | map-1- | 2 (refcount) | | |
| 621 // | map-1-a | b | | |
| 622 | |
| 623 // Example, data after deep copy copy: | |
| 624 // | namespace-1-(1 = namespace id) | dummy | | |
| 625 // | namespace-1-origin1 | 1 (mapid) | | |
| 626 // | namespace-2- | dummy | | |
| 627 // | namespace-2-origin1 | 2 (mapid) << references the new map | |
| 628 // | map-1- | 1 (dec. refcount) | | |
| 629 // | map-1-a | b | | |
| 630 // | map-2- | 1 (refcount) | | |
| 631 // | map-2-a | b | | |
| 632 | |
| 633 // Read the values from the old map here. If we don't need to copy the data, | |
| 634 // this can stay empty. | |
| 635 ValuesMap values; | |
| 636 if (copy_data && !ReadMap(*map_id, leveldb::ReadOptions(), &values, false)) | |
| 637 return false; | |
| 638 if (!DecreaseMapRefCount(*map_id, 1, batch)) | |
| 639 return false; | |
| 640 // Create a new map (this will also break the association to the old map) and | |
| 641 // write the old data into it. This will write the id of the created map into | |
| 642 // |map_id|. | |
| 643 if (!CreateMapForArea(namespace_id, origin, map_id, batch)) | |
| 644 return false; | |
| 645 WriteValuesToMap(*map_id, values, batch); | |
| 646 return true; | |
| 647 } | |
| 648 | |
| 649 std::string SessionStorageDatabase::NamespaceStartKey( | |
| 650 const std::string& namespace_id) { | |
| 651 return base::StringPrintf("namespace-%s-", namespace_id.c_str()); | |
| 652 } | |
| 653 | |
| 654 std::string SessionStorageDatabase::NamespaceKey( | |
| 655 const std::string& namespace_id, const std::string& origin) { | |
| 656 return base::StringPrintf("namespace-%s-%s", namespace_id.c_str(), | |
| 657 origin.c_str()); | |
| 658 } | |
| 659 | |
| 660 const char* SessionStorageDatabase::NamespacePrefix() { | |
| 661 return "namespace-"; | |
| 662 } | |
| 663 | |
| 664 std::string SessionStorageDatabase::MapRefCountKey(const std::string& map_id) { | |
| 665 return base::StringPrintf("map-%s-", map_id.c_str()); | |
| 666 } | |
| 667 | |
| 668 std::string SessionStorageDatabase::MapKey(const std::string& map_id, | |
| 669 const std::string& key) { | |
| 670 return base::StringPrintf("map-%s-%s", map_id.c_str(), key.c_str()); | |
| 671 } | |
| 672 | |
| 673 const char* SessionStorageDatabase::NextMapIdKey() { | |
| 674 return "next-map-id"; | |
| 675 } | |
| 676 | |
| 677 } // namespace dom_storage | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 22297005:
Move webkit/{browser,common}/dom_storage into content/ (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src