| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "content/browser/dom_storage/session_storage_database.h" |
| |
| #include <vector> |
| |
| #include "base/files/file_util.h" |
| #include "base/logging.h" |
| #include "base/metrics/histogram.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/stringprintf.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "third_party/leveldatabase/env_chromium.h" |
| #include "third_party/leveldatabase/src/include/leveldb/db.h" |
| #include "third_party/leveldatabase/src/include/leveldb/iterator.h" |
| #include "third_party/leveldatabase/src/include/leveldb/options.h" |
| #include "third_party/leveldatabase/src/include/leveldb/status.h" |
| #include "third_party/leveldatabase/src/include/leveldb/write_batch.h" |
| #include "url/gurl.h" |
| |
| |
| namespace { |
| |
| const char session_storage_uma_name[] = "SessionStorageDatabase.Open"; |
| |
| enum SessionStorageUMA { |
| SESSION_STORAGE_UMA_SUCCESS, |
| SESSION_STORAGE_UMA_RECREATED, |
| SESSION_STORAGE_UMA_FAIL, |
| SESSION_STORAGE_UMA_MAX |
| }; |
| |
| } // namespace |
| |
| // Layout of the database: |
| // | key | value | |
| // ----------------------------------------------------------------------- |
| // | map-1- | 2 (refcount, start of map-1-* keys)| |
| // | map-1-a | b (a = b in map 1) | |
| // | ... | | |
| // | namespace- | dummy (start of namespace-* keys) | |
| // | namespace-1- (1 = namespace id)| dummy (start of namespace-1-* keys)| |
| // | namespace-1-origin1 | 1 (mapid) | |
| // | namespace-1-origin2 | 2 | |
| // | namespace-2- | dummy | |
| // | namespace-2-origin1 | 1 (shallow copy) | |
| // | namespace-2-origin2 | 2 (shallow copy) | |
| // | namespace-3- | dummy | |
| // | namespace-3-origin1 | 3 (deep copy) | |
| // | namespace-3-origin2 | 2 (shallow copy) | |
| // | next-map-id | 4 | |
| |
| namespace content { |
| |
| // This class keeps track of ongoing operations across different threads. When |
| // DB inconsistency is detected, we need to 1) make sure no new operations start |
| // 2) wait until all current operations finish, and let the last one of them |
| // close the DB and delete the data. The DB will remain empty for the rest of |
| // the run, and will be recreated during the next run. We cannot hope to recover |
| // during this run, since the upper layer will have a different idea about what |
| // should be in the database. |
| class SessionStorageDatabase::DBOperation { |
| public: |
| explicit DBOperation(SessionStorageDatabase* session_storage_database) |
| : session_storage_database_(session_storage_database) { |
| base::AutoLock auto_lock(session_storage_database_->db_lock_); |
| ++session_storage_database_->operation_count_; |
| } |
| |
| ~DBOperation() { |
| base::AutoLock auto_lock(session_storage_database_->db_lock_); |
| --session_storage_database_->operation_count_; |
| if ((session_storage_database_->is_inconsistent_ || |
| session_storage_database_->db_error_) && |
| session_storage_database_->operation_count_ == 0 && |
| !session_storage_database_->invalid_db_deleted_) { |
| // No other operations are ongoing and the data is bad -> delete it now. |
| session_storage_database_->db_.reset(); |
| leveldb::DestroyDB(session_storage_database_->file_path_.AsUTF8Unsafe(), |
| leveldb::Options()); |
| session_storage_database_->invalid_db_deleted_ = true; |
| } |
| } |
| |
| private: |
| SessionStorageDatabase* session_storage_database_; |
| }; |
| |
| |
| SessionStorageDatabase::SessionStorageDatabase(const base::FilePath& file_path) |
| : file_path_(file_path), |
| db_error_(false), |
| is_inconsistent_(false), |
| invalid_db_deleted_(false), |
| operation_count_(0) { |
| } |
| |
| SessionStorageDatabase::~SessionStorageDatabase() { |
| } |
| |
| void SessionStorageDatabase::ReadAreaValues(const std::string& namespace_id, |
| const GURL& origin, |
| DOMStorageValuesMap* result) { |
| // We don't create a database if it doesn't exist. In that case, there is |
| // nothing to be added to the result. |
| if (!LazyOpen(false)) |
| return; |
| DBOperation operation(this); |
| |
| // While ReadAreaValues is in progress, another thread can call |
| // CommitAreaChanges. CommitAreaChanges might update map ref count key while |
| // this thread is iterating over the map ref count key. To protect the reading |
| // operation, create a snapshot and read from it. |
| leveldb::ReadOptions options; |
| options.snapshot = db_->GetSnapshot(); |
| |
| std::string map_id; |
| bool exists; |
| if (GetMapForArea(namespace_id, origin.spec(), options, &exists, &map_id) && |
| exists) |
| ReadMap(map_id, options, result, false); |
| db_->ReleaseSnapshot(options.snapshot); |
| } |
| |
| bool SessionStorageDatabase::CommitAreaChanges( |
| const std::string& namespace_id, |
| const GURL& origin, |
| bool clear_all_first, |
| const DOMStorageValuesMap& changes) { |
| // Even if |changes| is empty, we need to write the appropriate placeholders |
| // in the database, so that it can be later shallow-copied successfully. |
| if (!LazyOpen(true)) |
| return false; |
| DBOperation operation(this); |
| |
| leveldb::WriteBatch batch; |
| // Ensure that the keys "namespace-" "namespace-N" (see the schema above) |
| // exist. |
| const bool kOkIfExists = true; |
| if (!CreateNamespace(namespace_id, kOkIfExists, &batch)) |
| return false; |
| |
| std::string map_id; |
| bool exists; |
| if (!GetMapForArea(namespace_id, origin.spec(), leveldb::ReadOptions(), |
| &exists, &map_id)) |
| return false; |
| if (exists) { |
| int64 ref_count; |
| if (!GetMapRefCount(map_id, &ref_count)) |
| return false; |
| if (ref_count > 1) { |
| if (!DeepCopyArea(namespace_id, origin, !clear_all_first, |
| &map_id, &batch)) |
| return false; |
| } else if (clear_all_first) { |
| if (!ClearMap(map_id, &batch)) |
| return false; |
| } |
| } else { |
| // Map doesn't exist, create it now if needed. |
| if (!changes.empty()) { |
| if (!CreateMapForArea(namespace_id, origin, &map_id, &batch)) |
| return false; |
| } |
| } |
| |
| WriteValuesToMap(map_id, changes, &batch); |
| |
| leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| UMA_HISTOGRAM_ENUMERATION("SessionStorageDatabase.Commit", |
| leveldb_env::GetLevelDBStatusUMAValue(s), |
| leveldb_env::LEVELDB_STATUS_MAX); |
| return DatabaseErrorCheck(s.ok()); |
| } |
| |
| bool SessionStorageDatabase::CloneNamespace( |
| const std::string& namespace_id, const std::string& new_namespace_id) { |
| // Go through all origins in the namespace |namespace_id|, create placeholders |
| // for them in |new_namespace_id|, and associate them with the existing maps. |
| |
| // Example, data before shallow copy: |
| // | map-1- | 1 (refcount) | |
| // | map-1-a | b | |
| // | namespace-1- (1 = namespace id)| dummy | |
| // | namespace-1-origin1 | 1 (mapid) | |
| |
| // Example, data after shallow copy: |
| // | map-1- | 2 (inc. refcount) | |
| // | map-1-a | b | |
| // | namespace-1-(1 = namespace id) | dummy | |
| // | namespace-1-origin1 | 1 (mapid) | |
| // | namespace-2- | dummy | |
| // | namespace-2-origin1 | 1 (mapid) << references the same map |
| |
| if (!LazyOpen(true)) |
| return false; |
| DBOperation operation(this); |
| |
| leveldb::WriteBatch batch; |
| const bool kOkIfExists = false; |
| if (!CreateNamespace(new_namespace_id, kOkIfExists, &batch)) |
| return false; |
| |
| std::map<std::string, std::string> areas; |
| if (!GetAreasInNamespace(namespace_id, &areas)) |
| return false; |
| |
| for (std::map<std::string, std::string>::const_iterator it = areas.begin(); |
| it != areas.end(); ++it) { |
| const std::string& origin = it->first; |
| const std::string& map_id = it->second; |
| if (!IncreaseMapRefCount(map_id, &batch)) |
| return false; |
| AddAreaToNamespace(new_namespace_id, origin, map_id, &batch); |
| } |
| leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| return DatabaseErrorCheck(s.ok()); |
| } |
| |
| bool SessionStorageDatabase::DeleteArea(const std::string& namespace_id, |
| const GURL& origin) { |
| if (!LazyOpen(false)) { |
| // No need to create the database if it doesn't exist. |
| return true; |
| } |
| DBOperation operation(this); |
| leveldb::WriteBatch batch; |
| if (!DeleteAreaHelper(namespace_id, origin.spec(), &batch)) |
| return false; |
| leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| return DatabaseErrorCheck(s.ok()); |
| } |
| |
| bool SessionStorageDatabase::DeleteNamespace(const std::string& namespace_id) { |
| { |
| // The caller should have called other methods to open the DB before this |
| // function. Otherwise, DB stores nothing interesting related to the |
| // specified namespace. |
| // Do nothing if the DB is not open (or we know it has failed already), |
| base::AutoLock auto_lock(db_lock_); |
| if (!IsOpen() || db_error_ || is_inconsistent_) |
| return false; |
| } |
| DBOperation operation(this); |
| // Itereate through the areas in the namespace. |
| leveldb::WriteBatch batch; |
| std::map<std::string, std::string> areas; |
| if (!GetAreasInNamespace(namespace_id, &areas)) |
| return false; |
| for (std::map<std::string, std::string>::const_iterator it = areas.begin(); |
| it != areas.end(); ++it) { |
| const std::string& origin = it->first; |
| if (!DeleteAreaHelper(namespace_id, origin, &batch)) |
| return false; |
| } |
| batch.Delete(NamespaceStartKey(namespace_id)); |
| leveldb::Status s = db_->Write(leveldb::WriteOptions(), &batch); |
| return DatabaseErrorCheck(s.ok()); |
| } |
| |
| bool SessionStorageDatabase::ReadNamespacesAndOrigins( |
| std::map<std::string, std::vector<GURL> >* namespaces_and_origins) { |
| if (!LazyOpen(true)) |
| return false; |
| DBOperation operation(this); |
| |
| // While ReadNamespacesAndOrigins is in progress, another thread can call |
| // CommitAreaChanges. To protect the reading operation, create a snapshot and |
| // read from it. |
| leveldb::ReadOptions options; |
| options.snapshot = db_->GetSnapshot(); |
| |
| std::string namespace_prefix = NamespacePrefix(); |
| scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); |
| it->Seek(namespace_prefix); |
| // If the key is not found, the status of the iterator won't be IsNotFound(), |
| // but the iterator will be invalid. |
| if (!it->Valid()) { |
| db_->ReleaseSnapshot(options.snapshot); |
| return true; |
| } |
| |
| if (!DatabaseErrorCheck(it->status().ok())) { |
| db_->ReleaseSnapshot(options.snapshot); |
| return false; |
| } |
| |
| // Skip the dummy entry "namespace-" and iterate the namespaces. |
| std::string current_namespace_start_key; |
| std::string current_namespace_id; |
| for (it->Next(); it->Valid(); it->Next()) { |
| std::string key = it->key().ToString(); |
| if (key.find(namespace_prefix) != 0) { |
| // Iterated past the "namespace-" keys. |
| break; |
| } |
| // For each namespace, the first key is "namespace-<namespaceid>-", and the |
| // subsequent keys are "namespace-<namespaceid>-<origin>". Read the unique |
| // "<namespaceid>" parts from the keys. |
| if (current_namespace_start_key.empty() || |
| key.substr(0, current_namespace_start_key.length()) != |
| current_namespace_start_key) { |
| // The key is of the form "namespace-<namespaceid>-" for a new |
| // <namespaceid>. |
| current_namespace_start_key = key; |
| current_namespace_id = |
| key.substr(namespace_prefix.length(), |
| key.length() - namespace_prefix.length() - 1); |
| // Ensure that we keep track of the namespace even if it doesn't contain |
| // any origins. |
| namespaces_and_origins->insert( |
| std::make_pair(current_namespace_id, std::vector<GURL>())); |
| } else { |
| // The key is of the form "namespace-<namespaceid>-<origin>". |
| std::string origin = key.substr(current_namespace_start_key.length()); |
| (*namespaces_and_origins)[current_namespace_id].push_back(GURL(origin)); |
| } |
| } |
| db_->ReleaseSnapshot(options.snapshot); |
| return true; |
| } |
| |
| bool SessionStorageDatabase::LazyOpen(bool create_if_needed) { |
| base::AutoLock auto_lock(db_lock_); |
| if (db_error_ || is_inconsistent_) { |
| // Don't try to open a database that we know has failed already. |
| return false; |
| } |
| if (IsOpen()) |
| return true; |
| |
| if (!create_if_needed && |
| (!base::PathExists(file_path_) || base::IsDirectoryEmpty(file_path_))) { |
| // If the directory doesn't exist already and we haven't been asked to |
| // create a file on disk, then we don't bother opening the database. This |
| // means we wait until we absolutely need to put something onto disk before |
| // we do so. |
| return false; |
| } |
| |
| leveldb::DB* db; |
| leveldb::Status s = TryToOpen(&db); |
| if (!s.ok()) { |
| LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() |
| << ", error: " << s.ToString(); |
| DCHECK(db == NULL); |
| |
| // Clear the directory and try again. |
| base::DeleteFile(file_path_, true); |
| s = TryToOpen(&db); |
| if (!s.ok()) { |
| LOG(WARNING) << "Failed to open leveldb in " << file_path_.value() |
| << ", error: " << s.ToString(); |
| UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| SESSION_STORAGE_UMA_FAIL, |
| SESSION_STORAGE_UMA_MAX); |
| DCHECK(db == NULL); |
| db_error_ = true; |
| return false; |
| } |
| UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| SESSION_STORAGE_UMA_RECREATED, |
| SESSION_STORAGE_UMA_MAX); |
| } else { |
| UMA_HISTOGRAM_ENUMERATION(session_storage_uma_name, |
| SESSION_STORAGE_UMA_SUCCESS, |
| SESSION_STORAGE_UMA_MAX); |
| } |
| db_.reset(db); |
| return true; |
| } |
| |
| leveldb::Status SessionStorageDatabase::TryToOpen(leveldb::DB** db) { |
| leveldb::Options options; |
| // The directory exists but a valid leveldb database might not exist inside it |
| // (e.g., a subset of the needed files might be missing). Handle this |
| // situation gracefully by creating the database now. |
| options.max_open_files = 0; // Use minimum. |
| options.create_if_missing = true; |
| options.reuse_logs = leveldb_env::kDefaultLogReuseOptionValue; |
| return leveldb::DB::Open(options, file_path_.AsUTF8Unsafe(), db); |
| } |
| |
| bool SessionStorageDatabase::IsOpen() const { |
| return db_.get() != NULL; |
| } |
| |
| bool SessionStorageDatabase::CallerErrorCheck(bool ok) const { |
| DCHECK(ok); |
| return ok; |
| } |
| |
| bool SessionStorageDatabase::ConsistencyCheck(bool ok) { |
| if (ok) |
| return true; |
| base::AutoLock auto_lock(db_lock_); |
| // We cannot recover the database during this run, e.g., the upper layer can |
| // have a different understanding of the database state (shallow and deep |
| // copies). Make further operations fail. The next operation that finishes |
| // will delete the data, and next run will recerate the database. |
| is_inconsistent_ = true; |
| return false; |
| } |
| |
| bool SessionStorageDatabase::DatabaseErrorCheck(bool ok) { |
| if (ok) |
| return true; |
| base::AutoLock auto_lock(db_lock_); |
| // Make further operations fail. The next operation that finishes |
| // will delete the data, and next run will recerate the database. |
| db_error_ = true; |
| return false; |
| } |
| |
| bool SessionStorageDatabase::CreateNamespace(const std::string& namespace_id, |
| bool ok_if_exists, |
| leveldb::WriteBatch* batch) { |
| leveldb::Slice namespace_prefix = NamespacePrefix(); |
| std::string dummy; |
| leveldb::Status s = db_->Get(leveldb::ReadOptions(), namespace_prefix, |
| &dummy); |
| if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| return false; |
| if (s.IsNotFound()) |
| batch->Put(namespace_prefix, ""); |
| |
| std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| s = db_->Get(leveldb::ReadOptions(), namespace_start_key, &dummy); |
| if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| return false; |
| if (s.IsNotFound()) { |
| batch->Put(namespace_start_key, ""); |
| return true; |
| } |
| return CallerErrorCheck(ok_if_exists); |
| } |
| |
| bool SessionStorageDatabase::GetAreasInNamespace( |
| const std::string& namespace_id, |
| std::map<std::string, std::string>* areas) { |
| std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); |
| it->Seek(namespace_start_key); |
| // If the key is not found, the status of the iterator won't be IsNotFound(), |
| // but the iterator will be invalid. |
| if (!it->Valid()) { |
| // The namespace_start_key is not found when the namespace doesn't contain |
| // any areas. We don't need to do anything. |
| return true; |
| } |
| if (!DatabaseErrorCheck(it->status().ok())) |
| return false; |
| |
| // Skip the dummy entry "namespace-<namespaceid>-" and iterate the origins. |
| for (it->Next(); it->Valid(); it->Next()) { |
| std::string key = it->key().ToString(); |
| if (key.find(namespace_start_key) != 0) { |
| // Iterated past the origins for this namespace. |
| break; |
| } |
| std::string origin = key.substr(namespace_start_key.length()); |
| std::string map_id = it->value().ToString(); |
| (*areas)[origin] = map_id; |
| } |
| return true; |
| } |
| |
| void SessionStorageDatabase::AddAreaToNamespace(const std::string& namespace_id, |
| const std::string& origin, |
| const std::string& map_id, |
| leveldb::WriteBatch* batch) { |
| std::string namespace_key = NamespaceKey(namespace_id, origin); |
| batch->Put(namespace_key, map_id); |
| } |
| |
| bool SessionStorageDatabase::DeleteAreaHelper( |
| const std::string& namespace_id, |
| const std::string& origin, |
| leveldb::WriteBatch* batch) { |
| std::string map_id; |
| bool exists; |
| if (!GetMapForArea(namespace_id, origin, leveldb::ReadOptions(), &exists, |
| &map_id)) |
| return false; |
| if (!exists) |
| return true; // Nothing to delete. |
| if (!DecreaseMapRefCount(map_id, 1, batch)) |
| return false; |
| std::string namespace_key = NamespaceKey(namespace_id, origin); |
| batch->Delete(namespace_key); |
| |
| // If this was the only area in the namespace, delete the namespace start key, |
| // too. |
| std::string namespace_start_key = NamespaceStartKey(namespace_id); |
| scoped_ptr<leveldb::Iterator> it(db_->NewIterator(leveldb::ReadOptions())); |
| it->Seek(namespace_start_key); |
| if (!ConsistencyCheck(it->Valid())) |
| return false; |
| // Advance the iterator 2 times (we still haven't really deleted |
| // namespace_key). |
| it->Next(); |
| if (!ConsistencyCheck(it->Valid())) |
| return false; |
| it->Next(); |
| if (!it->Valid()) |
| return true; |
| std::string key = it->key().ToString(); |
| if (key.find(namespace_start_key) != 0) |
| batch->Delete(namespace_start_key); |
| return true; |
| } |
| |
| bool SessionStorageDatabase::GetMapForArea(const std::string& namespace_id, |
| const std::string& origin, |
| const leveldb::ReadOptions& options, |
| bool* exists, std::string* map_id) { |
| std::string namespace_key = NamespaceKey(namespace_id, origin); |
| leveldb::Status s = db_->Get(options, namespace_key, map_id); |
| if (s.IsNotFound()) { |
| *exists = false; |
| return true; |
| } |
| *exists = true; |
| return DatabaseErrorCheck(s.ok()); |
| } |
| |
| bool SessionStorageDatabase::CreateMapForArea(const std::string& namespace_id, |
| const GURL& origin, |
| std::string* map_id, |
| leveldb::WriteBatch* batch) { |
| leveldb::Slice next_map_id_key = NextMapIdKey(); |
| leveldb::Status s = db_->Get(leveldb::ReadOptions(), next_map_id_key, map_id); |
| if (!DatabaseErrorCheck(s.ok() || s.IsNotFound())) |
| return false; |
| int64 next_map_id = 0; |
| if (s.IsNotFound()) { |
| *map_id = "0"; |
| } else { |
| bool conversion_ok = base::StringToInt64(*map_id, &next_map_id); |
| if (!ConsistencyCheck(conversion_ok)) |
| return false; |
| } |
| batch->Put(next_map_id_key, base::Int64ToString(++next_map_id)); |
| std::string namespace_key = NamespaceKey(namespace_id, origin.spec()); |
| batch->Put(namespace_key, *map_id); |
| batch->Put(MapRefCountKey(*map_id), "1"); |
| return true; |
| } |
| |
| bool SessionStorageDatabase::ReadMap(const std::string& map_id, |
| const leveldb::ReadOptions& options, |
| DOMStorageValuesMap* result, |
| bool only_keys) { |
| scoped_ptr<leveldb::Iterator> it(db_->NewIterator(options)); |
| std::string map_start_key = MapRefCountKey(map_id); |
| it->Seek(map_start_key); |
| // If the key is not found, the status of the iterator won't be IsNotFound(), |
| // but the iterator will be invalid. The map needs to exist, otherwise we have |
| // a stale map_id in the database. |
| if (!ConsistencyCheck(it->Valid())) |
| return false; |
| if (!DatabaseErrorCheck(it->status().ok())) |
| return false; |
| // Skip the dummy entry "map-<mapid>-". |
| for (it->Next(); it->Valid(); it->Next()) { |
| std::string key = it->key().ToString(); |
| if (key.find(map_start_key) != 0) { |
| // Iterated past the keys in this map. |
| break; |
| } |
| // Key is of the form "map-<mapid>-<key>". |
| base::string16 key16 = |
| base::UTF8ToUTF16(key.substr(map_start_key.length())); |
| if (only_keys) { |
| (*result)[key16] = base::NullableString16(); |
| } else { |
| // Convert the raw data stored in std::string (it->value()) to raw data |
| // stored in base::string16. |
| size_t len = it->value().size() / sizeof(base::char16); |
| const base::char16* data_ptr = |
| reinterpret_cast<const base::char16*>(it->value().data()); |
| (*result)[key16] = |
| base::NullableString16(base::string16(data_ptr, len), false); |
| } |
| } |
| return true; |
| } |
| |
| void SessionStorageDatabase::WriteValuesToMap(const std::string& map_id, |
| const DOMStorageValuesMap& values, |
| leveldb::WriteBatch* batch) { |
| for (DOMStorageValuesMap::const_iterator it = values.begin(); |
| it != values.end(); |
| ++it) { |
| base::NullableString16 value = it->second; |
| std::string key = MapKey(map_id, base::UTF16ToUTF8(it->first)); |
| if (value.is_null()) { |
| batch->Delete(key); |
| } else { |
| // Convert the raw data stored in base::string16 to raw data stored in |
| // std::string. |
| const char* data = reinterpret_cast<const char*>(value.string().data()); |
| size_t size = value.string().size() * 2; |
| batch->Put(key, leveldb::Slice(data, size)); |
| } |
| } |
| } |
| |
| bool SessionStorageDatabase::GetMapRefCount(const std::string& map_id, |
| int64* ref_count) { |
| std::string ref_count_string; |
| leveldb::Status s = db_->Get(leveldb::ReadOptions(), |
| MapRefCountKey(map_id), &ref_count_string); |
| if (!ConsistencyCheck(s.ok())) |
| return false; |
| bool conversion_ok = base::StringToInt64(ref_count_string, ref_count); |
| return ConsistencyCheck(conversion_ok); |
| } |
| |
| bool SessionStorageDatabase::IncreaseMapRefCount(const std::string& map_id, |
| leveldb::WriteBatch* batch) { |
| // Increase the ref count for the map. |
| int64 old_ref_count; |
| if (!GetMapRefCount(map_id, &old_ref_count)) |
| return false; |
| batch->Put(MapRefCountKey(map_id), base::Int64ToString(++old_ref_count)); |
| return true; |
| } |
| |
| bool SessionStorageDatabase::DecreaseMapRefCount(const std::string& map_id, |
| int decrease, |
| leveldb::WriteBatch* batch) { |
| // Decrease the ref count for the map. |
| int64 ref_count; |
| if (!GetMapRefCount(map_id, &ref_count)) |
| return false; |
| if (!ConsistencyCheck(decrease <= ref_count)) |
| return false; |
| ref_count -= decrease; |
| if (ref_count > 0) { |
| batch->Put(MapRefCountKey(map_id), base::Int64ToString(ref_count)); |
| } else { |
| // Clear all keys in the map. |
| if (!ClearMap(map_id, batch)) |
| return false; |
| batch->Delete(MapRefCountKey(map_id)); |
| } |
| return true; |
| } |
| |
| bool SessionStorageDatabase::ClearMap(const std::string& map_id, |
| leveldb::WriteBatch* batch) { |
| DOMStorageValuesMap values; |
| if (!ReadMap(map_id, leveldb::ReadOptions(), &values, true)) |
| return false; |
| for (DOMStorageValuesMap::const_iterator it = values.begin(); |
| it != values.end(); ++it) |
| batch->Delete(MapKey(map_id, base::UTF16ToUTF8(it->first))); |
| return true; |
| } |
| |
| bool SessionStorageDatabase::DeepCopyArea( |
| const std::string& namespace_id, const GURL& origin, bool copy_data, |
| std::string* map_id, leveldb::WriteBatch* batch) { |
| // Example, data before deep copy: |
| // | namespace-1- (1 = namespace id)| dummy | |
| // | namespace-1-origin1 | 1 (mapid) | |
| // | namespace-2- | dummy | |
| // | namespace-2-origin1 | 1 (mapid) << references the same map |
| // | map-1- | 2 (refcount) | |
| // | map-1-a | b | |
| |
| // Example, data after deep copy copy: |
| // | namespace-1-(1 = namespace id) | dummy | |
| // | namespace-1-origin1 | 1 (mapid) | |
| // | namespace-2- | dummy | |
| // | namespace-2-origin1 | 2 (mapid) << references the new map |
| // | map-1- | 1 (dec. refcount) | |
| // | map-1-a | b | |
| // | map-2- | 1 (refcount) | |
| // | map-2-a | b | |
| |
| // Read the values from the old map here. If we don't need to copy the data, |
| // this can stay empty. |
| DOMStorageValuesMap values; |
| if (copy_data && !ReadMap(*map_id, leveldb::ReadOptions(), &values, false)) |
| return false; |
| if (!DecreaseMapRefCount(*map_id, 1, batch)) |
| return false; |
| // Create a new map (this will also break the association to the old map) and |
| // write the old data into it. This will write the id of the created map into |
| // |map_id|. |
| if (!CreateMapForArea(namespace_id, origin, map_id, batch)) |
| return false; |
| WriteValuesToMap(*map_id, values, batch); |
| return true; |
| } |
| |
| std::string SessionStorageDatabase::NamespaceStartKey( |
| const std::string& namespace_id) { |
| return base::StringPrintf("namespace-%s-", namespace_id.c_str()); |
| } |
| |
| std::string SessionStorageDatabase::NamespaceKey( |
| const std::string& namespace_id, const std::string& origin) { |
| return base::StringPrintf("namespace-%s-%s", namespace_id.c_str(), |
| origin.c_str()); |
| } |
| |
| const char* SessionStorageDatabase::NamespacePrefix() { |
| return "namespace-"; |
| } |
| |
| std::string SessionStorageDatabase::MapRefCountKey(const std::string& map_id) { |
| return base::StringPrintf("map-%s-", map_id.c_str()); |
| } |
| |
| std::string SessionStorageDatabase::MapKey(const std::string& map_id, |
| const std::string& key) { |
| return base::StringPrintf("map-%s-%s", map_id.c_str(), key.c_str()); |
| } |
| |
| const char* SessionStorageDatabase::NextMapIdKey() { |
| return "next-map-id"; |
| } |
| |
| } // namespace content |
