| // 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/dom_storage_database.h" |
| |
| #include "base/bind.h" |
| #include "base/files/file_util.h" |
| #include "base/logging.h" |
| #include "sql/statement.h" |
| #include "sql/transaction.h" |
| #include "third_party/sqlite/sqlite3.h" |
| |
| namespace content { |
| |
| DOMStorageDatabase::DOMStorageDatabase(const base::FilePath& file_path) |
| : file_path_(file_path) { |
| // Note: in normal use we should never get an empty backing path here. |
| // However, the unit test for this class can contruct an instance |
| // with an empty path. |
| Init(); |
| } |
| |
| DOMStorageDatabase::DOMStorageDatabase() { |
| Init(); |
| } |
| |
| void DOMStorageDatabase::Init() { |
| failed_to_open_ = false; |
| tried_to_recreate_ = false; |
| known_to_be_empty_ = false; |
| } |
| |
| DOMStorageDatabase::~DOMStorageDatabase() { |
| if (known_to_be_empty_ && !file_path_.empty()) { |
| // Delete the db and any lingering journal file from disk. |
| Close(); |
| sql::Database::Delete(file_path_); |
| } |
| } |
| |
| void DOMStorageDatabase::ReadAllValues(DOMStorageValuesMap* result) { |
| if (!LazyOpen(false)) |
| return; |
| |
| sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, |
| "SELECT * from ItemTable")); |
| DCHECK(statement.is_valid()); |
| |
| while (statement.Step()) { |
| base::string16 key = statement.ColumnString16(0); |
| base::string16 value; |
| statement.ColumnBlobAsString16(1, &value); |
| (*result)[key] = base::NullableString16(value, false); |
| } |
| known_to_be_empty_ = result->empty(); |
| |
| // Drop SQLite's caches. |
| db_->TrimMemory(); |
| } |
| |
| bool DOMStorageDatabase::CommitChanges(bool clear_all_first, |
| const DOMStorageValuesMap& changes) { |
| if (!LazyOpen(!changes.empty())) { |
| // If we're being asked to commit changes that will result in an |
| // empty database, we return true if the database file doesn't exist. |
| return clear_all_first && changes.empty() && |
| !base::PathExists(file_path_); |
| } |
| |
| bool old_known_to_be_empty = known_to_be_empty_; |
| sql::Transaction transaction(db_.get()); |
| if (!transaction.Begin()) |
| return false; |
| |
| if (clear_all_first) { |
| if (!db_->Execute("DELETE FROM ItemTable")) |
| return false; |
| known_to_be_empty_ = true; |
| } |
| |
| bool did_delete = false; |
| bool did_insert = false; |
| auto it = changes.begin(); |
| for(; it != changes.end(); ++it) { |
| sql::Statement statement; |
| base::string16 key = it->first; |
| base::NullableString16 value = it->second; |
| if (value.is_null()) { |
| statement.Assign(db_->GetCachedStatement(SQL_FROM_HERE, |
| "DELETE FROM ItemTable WHERE key=?")); |
| statement.BindString16(0, key); |
| did_delete = true; |
| } else { |
| statement.Assign(db_->GetCachedStatement(SQL_FROM_HERE, |
| "INSERT INTO ItemTable VALUES (?,?)")); |
| statement.BindString16(0, key); |
| statement.BindBlob(1, value.string().data(), |
| value.string().length() * sizeof(base::char16)); |
| known_to_be_empty_ = false; |
| did_insert = true; |
| } |
| DCHECK(statement.is_valid()); |
| statement.Run(); |
| } |
| |
| if (!known_to_be_empty_ && did_delete && !did_insert) { |
| sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, |
| "SELECT count(key) from ItemTable")); |
| if (statement.Step()) |
| known_to_be_empty_ = statement.ColumnInt(0) == 0; |
| } |
| |
| bool success = transaction.Commit(); |
| if (!success) |
| known_to_be_empty_ = old_known_to_be_empty; |
| |
| // Drop SQLite's caches. |
| db_->TrimMemory(); |
| |
| return success; |
| } |
| |
| void DOMStorageDatabase::ReportMemoryUsage( |
| base::trace_event::ProcessMemoryDump* pmd, |
| const std::string& name) { |
| if (IsOpen()) |
| db_->ReportMemoryUsage(pmd, name); |
| } |
| |
| bool DOMStorageDatabase::LazyOpen(bool create_if_needed) { |
| if (failed_to_open_) { |
| // Don't try to open a database that we know has failed |
| // already. |
| return false; |
| } |
| |
| if (IsOpen()) |
| return true; |
| |
| bool database_exists = base::PathExists(file_path_); |
| |
| if (!database_exists && !create_if_needed) { |
| // If the file 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; |
| } |
| |
| db_.reset(new sql::Database()); |
| db_->set_histogram_tag("DOMStorageDatabase"); |
| |
| // This db does not use [meta] table, store mmap status data elsewhere. |
| db_->set_mmap_alt_status(); |
| |
| if (file_path_.empty()) { |
| // This code path should only be triggered by unit tests. |
| if (!db_->OpenInMemory()) { |
| NOTREACHED() << "Unable to open DOM storage database in memory."; |
| failed_to_open_ = true; |
| return false; |
| } |
| } else { |
| if (!db_->Open(file_path_)) { |
| LOG(ERROR) << "Unable to open DOM storage database at " |
| << file_path_.value() |
| << " error: " << db_->GetErrorMessage(); |
| if (database_exists && !tried_to_recreate_) |
| return DeleteFileAndRecreate(); |
| failed_to_open_ = true; |
| return false; |
| } |
| } |
| |
| // sql::Database uses UTF-8 encoding, but WebCore style databases use |
| // UTF-16, so ensure we match. |
| ignore_result(db_->Execute("PRAGMA encoding=\"UTF-16\"")); |
| |
| if (!database_exists) { |
| // This is a new database, create the table and we're done! |
| if (CreateTableV2()) |
| return true; |
| } else { |
| // The database exists already - check if we need to upgrade |
| // and whether it's usable (i.e. not corrupted). |
| SchemaVersion current_version = DetectSchemaVersion(); |
| |
| if (current_version == V2) |
| return true; |
| } |
| |
| // This is the exceptional case - to try and recover we'll attempt |
| // to delete the file and start again. |
| Close(); |
| return DeleteFileAndRecreate(); |
| } |
| |
| DOMStorageDatabase::SchemaVersion DOMStorageDatabase::DetectSchemaVersion() { |
| DCHECK(IsOpen()); |
| |
| // Connection::Open() may succeed even if the file we try and open is not a |
| // database, however in the case that the database is corrupted to the point |
| // that SQLite doesn't actually think it's a database, |
| // sql::Database::GetCachedStatement will DCHECK when we later try and |
| // run statements. So we run a query here that will not DCHECK but fail |
| // on an invalid database to verify that what we've opened is usable. |
| if (db_->ExecuteAndReturnErrorCode("PRAGMA auto_vacuum") != SQLITE_OK) |
| return INVALID; |
| |
| // Look at the current schema - if it doesn't look right, assume corrupt. |
| if (!db_->DoesTableExist("ItemTable") || |
| !db_->DoesColumnExist("ItemTable", "key") || |
| !db_->DoesColumnExist("ItemTable", "value")) |
| return INVALID; |
| |
| return V2; |
| } |
| |
| bool DOMStorageDatabase::CreateTableV2() { |
| DCHECK(IsOpen()); |
| |
| return db_->Execute( |
| "CREATE TABLE ItemTable (" |
| "key TEXT UNIQUE ON CONFLICT REPLACE, " |
| "value BLOB NOT NULL ON CONFLICT FAIL)"); |
| } |
| |
| bool DOMStorageDatabase::DeleteFileAndRecreate() { |
| DCHECK(!IsOpen()); |
| DCHECK(base::PathExists(file_path_)); |
| |
| // We should only try and do this once. |
| if (tried_to_recreate_) |
| return false; |
| |
| tried_to_recreate_ = true; |
| |
| // If it's not a directory and we can delete the file, try and open it again. |
| if (!base::DirectoryExists(file_path_) && sql::Database::Delete(file_path_)) { |
| return LazyOpen(true); |
| } |
| |
| failed_to_open_ = true; |
| return false; |
| } |
| |
| void DOMStorageDatabase::Close() { |
| db_.reset(nullptr); |
| } |
| |
| } // namespace content |