Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 1 | // Copyright 2013 The Chromium Authors. All rights reserved. |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 5 | #include "content/browser/dom_storage/session_storage_database.h" |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 6 | |
| 7 | #include "base/file_util.h" |
| 8 | #include "base/logging.h" |
| 9 | #include "base/metrics/histogram.h" |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 10 | #include "base/strings/string_number_conversions.h" |
Torne (Richard Coles) | 5e3f23d | 2013-06-11 16:24:11 +0100 | [diff] [blame] | 11 | #include "base/strings/stringprintf.h" |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 12 | #include "base/strings/utf_string_conversions.h" |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 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" |
Ben Murdoch | eb525c5 | 2013-07-10 11:40:50 +0100 | [diff] [blame] | 18 | #include "url/gurl.h" |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 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 | |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 52 | namespace content { |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 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, |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 65 | DOMStorageValuesMap* result) { |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 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 | |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 86 | bool SessionStorageDatabase::CommitAreaChanges( |
| 87 | const std::string& namespace_id, |
| 88 | const GURL& origin, |
| 89 | bool clear_all_first, |
| 90 | const DOMStorageValuesMap& changes) { |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 91 | // Even if |changes| is empty, we need to write the appropriate placeholders |
| 92 | // in the database, so that it can be later shallow-copied succssfully. |
| 93 | if (!LazyOpen(true)) |
| 94 | return false; |
| 95 | |
| 96 | leveldb::WriteBatch batch; |
| 97 | // Ensure that the keys "namespace-" "namespace-N" (see the schema above) |
| 98 | // exist. |
| 99 | const bool kOkIfExists = true; |
| 100 | if (!CreateNamespace(namespace_id, kOkIfExists, &batch)) |
| 101 | return false; |
| 102 | |
| 103 | std::string map_id; |
| 104 | bool exists; |
| 105 | if (!GetMapForArea(namespace_id, origin.spec(), leveldb::ReadOptions(), |
| 106 | &exists, &map_id)) |
| 107 | return false; |
| 108 | if (exists) { |
| 109 | int64 ref_count; |
| 110 | if (!GetMapRefCount(map_id, &ref_count)) |
| 111 | return false; |
| 112 | if (ref_count > 1) { |
| 113 | if (!DeepCopyArea(namespace_id, origin, !clear_all_first, |
| 114 | &map_id, &batch)) |
| 115 | return false; |
| 116 | } |
| 117 | else if (clear_all_first) { |
| 118 | if (!ClearMap(map_id, &batch)) |
| 119 | return false; |
| 120 | } |
| 121 | } else { |
| 122 | // Map doesn't exist, create it now if needed. |
| 123 | if (!changes.empty()) { |
| 124 | if (!CreateMapForArea(namespace_id, origin, &map_id, &batch)) |
| 125 | return false; |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | WriteValuesToMap(map_id, changes, &batch); |
| 130 | |
| 131 | leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| 132 | return DatabaseErrorCheck(s.ok()); |
| 133 | } |
| 134 | |
| 135 | bool SessionStorageDatabase::CloneNamespace( |
| 136 | const std::string& namespace_id, const std::string& new_namespace_id) { |
| 137 | // Go through all origins in the namespace |namespace_id|, create placeholders |
| 138 | // for them in |new_namespace_id|, and associate them with the existing maps. |
| 139 | |
| 140 | // Example, data before shallow copy: |
| 141 | // | map-1- | 1 (refcount) | |
| 142 | // | map-1-a | b | |
| 143 | // | namespace-1- (1 = namespace id)| dummy | |
| 144 | // | namespace-1-origin1 | 1 (mapid) | |
| 145 | |
| 146 | // Example, data after shallow copy: |
| 147 | // | map-1- | 2 (inc. refcount) | |
| 148 | // | map-1-a | b | |
| 149 | // | namespace-1-(1 = namespace id) | dummy | |
| 150 | // | namespace-1-origin1 | 1 (mapid) | |
| 151 | // | namespace-2- | dummy | |
| 152 | // | namespace-2-origin1 | 1 (mapid) << references the same map |
| 153 | |
| 154 | if (!LazyOpen(true)) |
| 155 | return false; |
| 156 | |
| 157 | leveldb::WriteBatch batch; |
| 158 | const bool kOkIfExists = false; |
| 159 | if (!CreateNamespace(new_namespace_id, kOkIfExists, &batch)) |
| 160 | return false; |
| 161 | |
| 162 | std::map<std::string, std::string> areas; |
| 163 | if (!GetAreasInNamespace(namespace_id, &areas)) |
| 164 | return false; |
| 165 | |
| 166 | for (std::map<std::string, std::string>::const_iterator it = areas.begin(); |
| 167 | it != areas.end(); ++it) { |
| 168 | const std::string& origin = it->first; |
| 169 | const std::string& map_id = it->second; |
| 170 | if (!IncreaseMapRefCount(map_id, &batch)) |
| 171 | return false; |
| 172 | AddAreaToNamespace(new_namespace_id, origin, map_id, &batch); |
| 173 | } |
| 174 | leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| 175 | return DatabaseErrorCheck(s.ok()); |
| 176 | } |
| 177 | |
| 178 | bool SessionStorageDatabase::DeleteArea(const std::string& namespace_id, |
| 179 | const GURL& origin) { |
| 180 | if (!LazyOpen(false)) { |
| 181 | // No need to create the database if it doesn't exist. |
| 182 | return true; |
| 183 | } |
| 184 | leveldb::WriteBatch batch; |
| 185 | if (!DeleteAreaHelper(namespace_id, origin.spec(), &batch)) |
| 186 | return false; |
| 187 | leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| 188 | return DatabaseErrorCheck(s.ok()); |
| 189 | } |
| 190 | |
| 191 | bool SessionStorageDatabase::DeleteNamespace(const std::string& namespace_id) { |
| 192 | if (!LazyOpen(false)) { |
| 193 | // No need to create the database if it doesn't exist. |
| 194 | return true; |
| 195 | } |
| 196 | // Itereate through the areas in the namespace. |
| 197 | leveldb::WriteBatch batch; |
| 198 | std::map<std::string, std::string> areas; |
| 199 | if (!GetAreasInNamespace(namespace_id, &areas)) |
| 200 | return false; |
| 201 | for (std::map<std::string, std::string>::const_iterator it = areas.begin(); |
| 202 | it != areas.end(); ++it) { |
| 203 | const std::string& origin = it->first; |
| 204 | if (!DeleteAreaHelper(namespace_id, origin, &batch)) |
| 205 | return false; |
| 206 | } |
| 207 | batch.Delete(NamespaceStartKey(namespace_id)); |
| 208 | leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| 209 | return DatabaseErrorCheck(s.ok()); |
| 210 | } |
| 211 | |
| 212 | bool SessionStorageDatabase::ReadNamespacesAndOrigins( |
| 213 | std::map<std::string, std::vector<GURL> >* namespaces_and_origins) { |
| 214 | if (!LazyOpen(true)) |
| 215 | return false; |
| 216 | |
| 217 | // While ReadNamespacesAndOrigins is in progress, another thread can call |
| 218 | // CommitAreaChanges. To protect the reading operation, create a snapshot and |
| 219 | // read from it. |
| 220 | leveldb::ReadOptions options; |
| 221 | options.snapshot = db_->GetSnapshot(); |
| 222 | |
| 223 | std::string namespace_prefix = NamespacePrefix(); |
| 224 | scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); |
| 225 | it->Seek(namespace_prefix); |
| 226 | // If the key is not found, the status of the iterator won't be IsNotFound(), |
| 227 | // but the iterator will be invalid. |
| 228 | if (!it->Valid()) { |
| 229 | db_->ReleaseSnapshot(options.snapshot); |
| 230 | return true; |
| 231 | } |
| 232 | |
| 233 | if (!DatabaseErrorCheck(it->status().ok())) { |
| 234 | db_->ReleaseSnapshot(options.snapshot); |
| 235 | return false; |
| 236 | } |
| 237 | |
| 238 | // Skip the dummy entry "namespace-" and iterate the namespaces. |
| 239 | std::string current_namespace_start_key; |
| 240 | std::string current_namespace_id; |
| 241 | for (it->Next(); it->Valid(); it->Next()) { |
| 242 | std::string key = it->key().ToString(); |
| 243 | if (key.find(namespace_prefix) != 0) { |
| 244 | // Iterated past the "namespace-" keys. |
| 245 | break; |
| 246 | } |
| 247 | // For each namespace, the first key is "namespace-<namespaceid>-", and the |
| 248 | // subsequent keys are "namespace-<namespaceid>-<origin>". Read the unique |
| 249 | // "<namespaceid>" parts from the keys. |
| 250 | if (current_namespace_start_key.empty() || |
| 251 | key.substr(0, current_namespace_start_key.length()) != |
| 252 | current_namespace_start_key) { |
| 253 | // The key is of the form "namespace-<namespaceid>-" for a new |
| 254 | // <namespaceid>. |
| 255 | current_namespace_start_key = key; |
| 256 | current_namespace_id = |
| 257 | key.substr(namespace_prefix.length(), |
| 258 | key.length() - namespace_prefix.length() - 1); |
| 259 | // Ensure that we keep track of the namespace even if it doesn't contain |
| 260 | // any origins. |
| 261 | namespaces_and_origins->insert( |
| 262 | std::make_pair(current_namespace_id, std::vector<GURL>())); |
| 263 | } else { |
| 264 | // The key is of the form "namespace-<namespaceid>-<origin>". |
| 265 | std::string origin = key.substr(current_namespace_start_key.length()); |
| 266 | (*namespaces_and_origins)[current_namespace_id].push_back(GURL(origin)); |
| 267 | } |
| 268 | } |
| 269 | db_->ReleaseSnapshot(options.snapshot); |
| 270 | return true; |
| 271 | } |
| 272 | |
| 273 | bool SessionStorageDatabase::LazyOpen(bool create_if_needed) { |
| 274 | base::AutoLock auto_lock(db_lock_); |
| 275 | if (db_error_ || is_inconsistent_) { |
| 276 | // Don't try to open a database that we know has failed already. |
| 277 | return false; |
| 278 | } |
| 279 | if (IsOpen()) |
| 280 | return true; |
| 281 | |
| 282 | if (!create_if_needed && |
Ben Murdoch | 7dbb3d5 | 2013-07-17 14:55:54 +0100 | [diff] [blame] | 283 | (!base::PathExists(file_path_) || |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 284 | file_util::IsDirectoryEmpty(file_path_))) { |
| 285 | // If the directory doesn't exist already and we haven't been asked to |
| 286 | // create a file on disk, then we don't bother opening the database. This |
| 287 | // means we wait until we absolutely need to put something onto disk before |
| 288 | // we do so. |
| 289 | return false; |
| 290 | } |
| 291 | |
| 292 | leveldb::DB* db; |
| 293 | leveldb::Status s = TryToOpen(&db); |
| 294 | if (!s.ok()) { |
| 295 | LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() |
| 296 | << ", error: " << s.ToString(); |
| 297 | DCHECK(db == NULL); |
| 298 | |
| 299 | // Clear the directory and try again. |
Ben Murdoch | 7dbb3d5 | 2013-07-17 14:55:54 +0100 | [diff] [blame] | 300 | base::DeleteFile(file_path_, true); |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 301 | s = TryToOpen(&db); |
| 302 | if (!s.ok()) { |
| 303 | LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() |
| 304 | << ", error: " << s.ToString(); |
| 305 | UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| 306 | SESSION_STORAGE_UMA_FAIL, |
| 307 | SESSION_STORAGE_UMA_MAX); |
| 308 | DCHECK(db == NULL); |
| 309 | db_error_ = true; |
| 310 | return false; |
| 311 | } |
| 312 | UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| 313 | SESSION_STORAGE_UMA_RECREATED, |
| 314 | SESSION_STORAGE_UMA_MAX); |
| 315 | } else { |
| 316 | UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| 317 | SESSION_STORAGE_UMA_SUCCESS, |
| 318 | SESSION_STORAGE_UMA_MAX); |
| 319 | } |
| 320 | db_.reset(db); |
| 321 | return true; |
| 322 | } |
| 323 | |
| 324 | leveldb::Status SessionStorageDatabase::TryToOpen(leveldb::DB** db) { |
| 325 | leveldb::Options options; |
| 326 | // The directory exists but a valid leveldb database might not exist inside it |
| 327 | // (e.g., a subset of the needed files might be missing). Handle this |
| 328 | // situation gracefully by creating the database now. |
Ben Murdoch | 7dbb3d5 | 2013-07-17 14:55:54 +0100 | [diff] [blame] | 329 | options.max_open_files = 0; // Use minimum. |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 330 | options.create_if_missing = true; |
| 331 | #if defined(OS_WIN) |
| 332 | return leveldb::DB::Open(options, WideToUTF8(file_path_.value()), db); |
| 333 | #elif defined(OS_POSIX) |
| 334 | return leveldb::DB::Open(options, file_path_.value(), db); |
| 335 | #endif |
| 336 | } |
| 337 | |
| 338 | bool SessionStorageDatabase::IsOpen() const { |
| 339 | return db_.get() != NULL; |
| 340 | } |
| 341 | |
| 342 | bool SessionStorageDatabase::CallerErrorCheck(bool ok) const { |
| 343 | DCHECK(ok); |
| 344 | return ok; |
| 345 | } |
| 346 | |
| 347 | bool SessionStorageDatabase::ConsistencyCheck(bool ok) { |
| 348 | if (ok) |
| 349 | return true; |
| 350 | base::AutoLock auto_lock(db_lock_); |
| 351 | DCHECK(false); |
| 352 | is_inconsistent_ = true; |
| 353 | // We cannot recover the database during this run, e.g., the upper layer can |
| 354 | // have a different understanding of the database state (shallow and deep |
| 355 | // copies). |
| 356 | // TODO(marja): Error handling. |
| 357 | return false; |
| 358 | } |
| 359 | |
| 360 | bool SessionStorageDatabase::DatabaseErrorCheck(bool ok) { |
| 361 | if (ok) |
| 362 | return true; |
| 363 | base::AutoLock auto_lock(db_lock_); |
| 364 | db_error_ = true; |
| 365 | // TODO(marja): Error handling. |
| 366 | return false; |
| 367 | } |
| 368 | |
| 369 | bool SessionStorageDatabase::CreateNamespace(const std::string& namespace_id, |
| 370 | bool ok_if_exists, |
| 371 | leveldb::WriteBatch* batch) { |
| 372 | leveldb::Slice namespace_prefix = NamespacePrefix(); |
| 373 | std::string dummy; |
| 374 | leveldb::Status s = db_->Get(leveldb::ReadOptions(), namespace_prefix, |
| 375 | &dummy); |
| 376 | if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| 377 | return false; |
| 378 | if (s.IsNotFound()) |
| 379 | batch->Put(namespace_prefix, ""); |
| 380 | |
| 381 | std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| 382 | s = db_->Get(leveldb::ReadOptions(), namespace_start_key, &dummy); |
| 383 | if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| 384 | return false; |
| 385 | if (s.IsNotFound()) { |
| 386 | batch->Put(namespace_start_key, ""); |
| 387 | return true; |
| 388 | } |
| 389 | return CallerErrorCheck(ok_if_exists); |
| 390 | } |
| 391 | |
| 392 | bool SessionStorageDatabase::GetAreasInNamespace( |
| 393 | const std::string& namespace_id, |
| 394 | std::map<std::string, std::string>* areas) { |
| 395 | std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| 396 | scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); |
| 397 | it->Seek(namespace_start_key); |
| 398 | // If the key is not found, the status of the iterator won't be IsNotFound(), |
| 399 | // but the iterator will be invalid. |
| 400 | if (!it->Valid()) { |
| 401 | // The namespace_start_key is not found when the namespace doesn't contain |
| 402 | // any areas. We don't need to do anything. |
| 403 | return true; |
| 404 | } |
| 405 | if (!DatabaseErrorCheck(it->status().ok())) |
| 406 | return false; |
| 407 | |
| 408 | // Skip the dummy entry "namespace-<namespaceid>-" and iterate the origins. |
| 409 | for (it->Next(); it->Valid(); it->Next()) { |
| 410 | std::string key = it->key().ToString(); |
| 411 | if (key.find(namespace_start_key) != 0) { |
| 412 | // Iterated past the origins for this namespace. |
| 413 | break; |
| 414 | } |
| 415 | std::string origin = key.substr(namespace_start_key.length()); |
| 416 | std::string map_id = it->value().ToString(); |
| 417 | (*areas)[origin] = map_id; |
| 418 | } |
| 419 | return true; |
| 420 | } |
| 421 | |
| 422 | void SessionStorageDatabase::AddAreaToNamespace(const std::string& namespace_id, |
| 423 | const std::string& origin, |
| 424 | const std::string& map_id, |
| 425 | leveldb::WriteBatch* batch) { |
| 426 | std::string namespace_key = NamespaceKey(namespace_id, origin); |
| 427 | batch->Put(namespace_key, map_id); |
| 428 | } |
| 429 | |
| 430 | bool SessionStorageDatabase::DeleteAreaHelper( |
| 431 | const std::string& namespace_id, |
| 432 | const std::string& origin, |
| 433 | leveldb::WriteBatch* batch) { |
| 434 | std::string map_id; |
| 435 | bool exists; |
| 436 | if (!GetMapForArea(namespace_id, origin, leveldb::ReadOptions(), &exists, |
| 437 | &map_id)) |
| 438 | return false; |
| 439 | if (!exists) |
| 440 | return true; // Nothing to delete. |
| 441 | if (!DecreaseMapRefCount(map_id, 1, batch)) |
| 442 | return false; |
| 443 | std::string namespace_key = NamespaceKey(namespace_id, origin); |
| 444 | batch->Delete(namespace_key); |
| 445 | |
| 446 | // If this was the only area in the namespace, delete the namespace start key, |
| 447 | // too. |
| 448 | std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| 449 | scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); |
| 450 | it->Seek(namespace_start_key); |
| 451 | if (!ConsistencyCheck(it->Valid())) |
| 452 | return false; |
| 453 | // Advance the iterator 2 times (we still haven't really deleted |
| 454 | // namespace_key). |
| 455 | it->Next(); |
| 456 | if (!ConsistencyCheck(it->Valid())) |
| 457 | return false; |
| 458 | it->Next(); |
| 459 | if (!it->Valid()) |
| 460 | return true; |
| 461 | std::string key = it->key().ToString(); |
| 462 | if (key.find(namespace_start_key) != 0) |
| 463 | batch->Delete(namespace_start_key); |
| 464 | return true; |
| 465 | } |
| 466 | |
| 467 | bool SessionStorageDatabase::GetMapForArea(const std::string& namespace_id, |
| 468 | const std::string& origin, |
| 469 | const leveldb::ReadOptions& options, |
| 470 | bool* exists, std::string* map_id) { |
| 471 | std::string namespace_key = NamespaceKey(namespace_id, origin); |
| 472 | leveldb::Status s = db_->Get(options, namespace_key, map_id); |
| 473 | if (s.IsNotFound()) { |
| 474 | *exists = false; |
| 475 | return true; |
| 476 | } |
| 477 | *exists = true; |
| 478 | return DatabaseErrorCheck(s.ok()); |
| 479 | } |
| 480 | |
| 481 | bool SessionStorageDatabase::CreateMapForArea(const std::string& namespace_id, |
| 482 | const GURL& origin, |
| 483 | std::string* map_id, |
| 484 | leveldb::WriteBatch* batch) { |
| 485 | leveldb::Slice next_map_id_key = NextMapIdKey(); |
| 486 | leveldb::Status s = db_->Get(leveldb::ReadOptions(), next_map_id_key, map_id); |
| 487 | if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| 488 | return false; |
| 489 | int64 next_map_id = 0; |
| 490 | if (s.IsNotFound()) { |
| 491 | *map_id = "0"; |
| 492 | } else { |
| 493 | bool conversion_ok = base::StringToInt64(*map_id, &next_map_id); |
| 494 | if (!ConsistencyCheck(conversion_ok)) |
| 495 | return false; |
| 496 | } |
| 497 | batch->Put(next_map_id_key, base::Int64ToString(++next_map_id)); |
| 498 | std::string namespace_key = NamespaceKey(namespace_id, origin.spec()); |
| 499 | batch->Put(namespace_key, *map_id); |
| 500 | batch->Put(MapRefCountKey(*map_id), "1"); |
| 501 | return true; |
| 502 | } |
| 503 | |
| 504 | bool SessionStorageDatabase::ReadMap(const std::string& map_id, |
| 505 | const leveldb::ReadOptions& options, |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 506 | DOMStorageValuesMap* result, |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 507 | bool only_keys) { |
| 508 | scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); |
| 509 | std::string map_start_key = MapRefCountKey(map_id); |
| 510 | it->Seek(map_start_key); |
| 511 | // If the key is not found, the status of the iterator won't be IsNotFound(), |
| 512 | // but the iterator will be invalid. The map needs to exist, otherwise we have |
| 513 | // a stale map_id in the database. |
| 514 | if (!ConsistencyCheck(it->Valid())) |
| 515 | return false; |
| 516 | if (!DatabaseErrorCheck(it->status().ok())) |
| 517 | return false; |
| 518 | // Skip the dummy entry "map-<mapid>-". |
| 519 | for (it->Next(); it->Valid(); it->Next()) { |
| 520 | std::string key = it->key().ToString(); |
| 521 | if (key.find(map_start_key) != 0) { |
| 522 | // Iterated past the keys in this map. |
| 523 | break; |
| 524 | } |
| 525 | // Key is of the form "map-<mapid>-<key>". |
| 526 | base::string16 key16 = UTF8ToUTF16(key.substr(map_start_key.length())); |
| 527 | if (only_keys) { |
Torne (Richard Coles) | 7d4cd47 | 2013-06-19 11:58:07 +0100 | [diff] [blame] | 528 | (*result)[key16] = base::NullableString16(); |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 529 | } else { |
| 530 | // Convert the raw data stored in std::string (it->value()) to raw data |
| 531 | // stored in base::string16. |
| 532 | size_t len = it->value().size() / sizeof(char16); |
| 533 | const char16* data_ptr = |
| 534 | reinterpret_cast<const char16*>(it->value().data()); |
Torne (Richard Coles) | 7d4cd47 | 2013-06-19 11:58:07 +0100 | [diff] [blame] | 535 | (*result)[key16] = |
| 536 | base::NullableString16(base::string16(data_ptr, len), false); |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 537 | } |
| 538 | } |
| 539 | return true; |
| 540 | } |
| 541 | |
| 542 | void SessionStorageDatabase::WriteValuesToMap(const std::string& map_id, |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 543 | const DOMStorageValuesMap& values, |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 544 | leveldb::WriteBatch* batch) { |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 545 | for (DOMStorageValuesMap::const_iterator it = values.begin(); |
| 546 | it != values.end(); |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 547 | ++it) { |
Torne (Richard Coles) | 7d4cd47 | 2013-06-19 11:58:07 +0100 | [diff] [blame] | 548 | base::NullableString16 value = it->second; |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 549 | std::string key = MapKey(map_id, UTF16ToUTF8(it->first)); |
| 550 | if (value.is_null()) { |
| 551 | batch->Delete(key); |
| 552 | } else { |
| 553 | // Convert the raw data stored in base::string16 to raw data stored in |
| 554 | // std::string. |
| 555 | const char* data = reinterpret_cast<const char*>(value.string().data()); |
| 556 | size_t size = value.string().size() * 2; |
| 557 | batch->Put(key, leveldb::Slice(data, size)); |
| 558 | } |
| 559 | } |
| 560 | } |
| 561 | |
| 562 | bool SessionStorageDatabase::GetMapRefCount(const std::string& map_id, |
| 563 | int64* ref_count) { |
| 564 | std::string ref_count_string; |
| 565 | leveldb::Status s = db_->Get(leveldb::ReadOptions(), |
| 566 | MapRefCountKey(map_id), &ref_count_string); |
| 567 | if (!ConsistencyCheck(s.ok())) |
| 568 | return false; |
| 569 | bool conversion_ok = base::StringToInt64(ref_count_string, ref_count); |
| 570 | return ConsistencyCheck(conversion_ok); |
| 571 | } |
| 572 | |
| 573 | bool SessionStorageDatabase::IncreaseMapRefCount(const std::string& map_id, |
| 574 | leveldb::WriteBatch* batch) { |
| 575 | // Increase the ref count for the map. |
| 576 | int64 old_ref_count; |
| 577 | if (!GetMapRefCount(map_id, &old_ref_count)) |
| 578 | return false; |
| 579 | batch->Put(MapRefCountKey(map_id), base::Int64ToString(++old_ref_count)); |
| 580 | return true; |
| 581 | } |
| 582 | |
| 583 | bool SessionStorageDatabase::DecreaseMapRefCount(const std::string& map_id, |
| 584 | int decrease, |
| 585 | leveldb::WriteBatch* batch) { |
| 586 | // Decrease the ref count for the map. |
| 587 | int64 ref_count; |
| 588 | if (!GetMapRefCount(map_id, &ref_count)) |
| 589 | return false; |
| 590 | if (!ConsistencyCheck(decrease <= ref_count)) |
| 591 | return false; |
| 592 | ref_count -= decrease; |
| 593 | if (ref_count > 0) { |
| 594 | batch->Put(MapRefCountKey(map_id), base::Int64ToString(ref_count)); |
| 595 | } else { |
| 596 | // Clear all keys in the map. |
| 597 | if (!ClearMap(map_id, batch)) |
| 598 | return false; |
| 599 | batch->Delete(MapRefCountKey(map_id)); |
| 600 | } |
| 601 | return true; |
| 602 | } |
| 603 | |
| 604 | bool SessionStorageDatabase::ClearMap(const std::string& map_id, |
| 605 | leveldb::WriteBatch* batch) { |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 606 | DOMStorageValuesMap values; |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 607 | if (!ReadMap(map_id, leveldb::ReadOptions(), &values, true)) |
| 608 | return false; |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 609 | for (DOMStorageValuesMap::const_iterator it = values.begin(); |
| 610 | it != values.end(); ++it) |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 611 | batch->Delete(MapKey(map_id, UTF16ToUTF8(it->first))); |
| 612 | return true; |
| 613 | } |
| 614 | |
| 615 | bool SessionStorageDatabase::DeepCopyArea( |
| 616 | const std::string& namespace_id, const GURL& origin, bool copy_data, |
| 617 | std::string* map_id, leveldb::WriteBatch* batch) { |
| 618 | // Example, data before deep copy: |
| 619 | // | namespace-1- (1 = namespace id)| dummy | |
| 620 | // | namespace-1-origin1 | 1 (mapid) | |
| 621 | // | namespace-2- | dummy | |
| 622 | // | namespace-2-origin1 | 1 (mapid) << references the same map |
| 623 | // | map-1- | 2 (refcount) | |
| 624 | // | map-1-a | b | |
| 625 | |
| 626 | // Example, data after deep copy copy: |
| 627 | // | namespace-1-(1 = namespace id) | dummy | |
| 628 | // | namespace-1-origin1 | 1 (mapid) | |
| 629 | // | namespace-2- | dummy | |
| 630 | // | namespace-2-origin1 | 2 (mapid) << references the new map |
| 631 | // | map-1- | 1 (dec. refcount) | |
| 632 | // | map-1-a | b | |
| 633 | // | map-2- | 1 (refcount) | |
| 634 | // | map-2-a | b | |
| 635 | |
| 636 | // Read the values from the old map here. If we don't need to copy the data, |
| 637 | // this can stay empty. |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 638 | DOMStorageValuesMap values; |
Torne (Richard Coles) | 868fa2f | 2013-06-11 10:57:03 +0100 | [diff] [blame] | 639 | if (copy_data && !ReadMap(*map_id, leveldb::ReadOptions(), &values, false)) |
| 640 | return false; |
| 641 | if (!DecreaseMapRefCount(*map_id, 1, batch)) |
| 642 | return false; |
| 643 | // Create a new map (this will also break the association to the old map) and |
| 644 | // write the old data into it. This will write the id of the created map into |
| 645 | // |map_id|. |
| 646 | if (!CreateMapForArea(namespace_id, origin, map_id, batch)) |
| 647 | return false; |
| 648 | WriteValuesToMap(*map_id, values, batch); |
| 649 | return true; |
| 650 | } |
| 651 | |
| 652 | std::string SessionStorageDatabase::NamespaceStartKey( |
| 653 | const std::string& namespace_id) { |
| 654 | return base::StringPrintf("namespace-%s-", namespace_id.c_str()); |
| 655 | } |
| 656 | |
| 657 | std::string SessionStorageDatabase::NamespaceKey( |
| 658 | const std::string& namespace_id, const std::string& origin) { |
| 659 | return base::StringPrintf("namespace-%s-%s", namespace_id.c_str(), |
| 660 | origin.c_str()); |
| 661 | } |
| 662 | |
| 663 | const char* SessionStorageDatabase::NamespacePrefix() { |
| 664 | return "namespace-"; |
| 665 | } |
| 666 | |
| 667 | std::string SessionStorageDatabase::MapRefCountKey(const std::string& map_id) { |
| 668 | return base::StringPrintf("map-%s-", map_id.c_str()); |
| 669 | } |
| 670 | |
| 671 | std::string SessionStorageDatabase::MapKey(const std::string& map_id, |
| 672 | const std::string& key) { |
| 673 | return base::StringPrintf("map-%s-%s", map_id.c_str(), key.c_str()); |
| 674 | } |
| 675 | |
| 676 | const char* SessionStorageDatabase::NextMapIdKey() { |
| 677 | return "next-map-id"; |
| 678 | } |
| 679 | |
Ben Murdoch | bb1529c | 2013-08-08 10:24:53 +0100 | [diff] [blame^] | 680 | } // namespace content |