1// Copyright 2013 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#ifndef NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_VERSION_H_
6#define NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_VERSION_H_
7
8namespace disk_cache {
9
10// Short rules helping to think about data upgrades within Simple Cache:
11//   * ALL changes of on-disk data format, backward-compatible or not,
12//     forward-compatible or not, require updating the |kSimpleVersion|.
13//   * All cache Upgrades are performed on backend start, must be finished
14//     before the new backend starts processing any incoming operations.
15//   * If the Upgrade is not implemented for transition from
16//     |kSimpleVersion - 1| then the whole cache directory will be cleared.
17//   * Dropping cache data on disk or some of its parts can be a valid way to
18//     Upgrade.
19const uint32 kSimpleVersion = 6;
20
21// The version of the entry file(s) as written to disk. Must be updated iff the
22// entry format changes with the overall backend version update.
23const uint32 kSimpleEntryVersionOnDisk = 5;
24
25}  // namespace disk_cache
26
27#endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_VERSION_H_
28