Change ServiceManager::SetLoaderForUrl() to SetLoaderForScheme()
[chromium-blink-merge.git] / sql / transaction.h
blob788a002f831228d9584968ec4cf50e485541c6a5
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.
5 #ifndef SQL_TRANSACTION_H_
6 #define SQL_TRANSACTION_H_
8 #include "base/basictypes.h"
9 #include "sql/sql_export.h"
11 namespace sql {
13 class Connection;
15 class SQL_EXPORT Transaction {
16 public:
17 // Creates the scoped transaction object. You MUST call Begin() to begin the
18 // transaction. If you have begun a transaction and not committed it, the
19 // constructor will roll back the transaction. If you want to commit, you
20 // need to manually call Commit before this goes out of scope.
22 // Nested transactions are supported. See sql::Connection::BeginTransaction
23 // for details.
24 explicit Transaction(Connection* connection);
25 ~Transaction();
27 // Returns true when there is a transaction that has been successfully begun.
28 bool is_open() const { return is_open_; }
30 // Begins the transaction. This uses the default sqlite "deferred" transaction
31 // type, which means that the DB lock is lazily acquired the next time the
32 // database is accessed, not in the begin transaction command.
34 // Returns false on failure. Note that if this fails, you shouldn't do
35 // anything you expect to be actually transactional, because it won't be!
36 bool Begin();
38 // Rolls back the transaction. This will happen automatically if you do
39 // nothing when the transaction goes out of scope.
40 void Rollback();
42 // Commits the transaction, returning true on success. This will return
43 // false if sqlite could not commit it, or if another transaction in the
44 // same outermost transaction has been rolled back (which necessitates a
45 // rollback of all transactions in that outermost one).
46 bool Commit();
48 private:
49 Connection* connection_;
51 // True when the transaction is open, false when it's already been committed
52 // or rolled back.
53 bool is_open_;
55 DISALLOW_COPY_AND_ASSIGN(Transaction);
58 } // namespace sql
60 #endif // SQL_TRANSACTION_H_