// Copyright (c) 2012 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.
#ifndef SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_
#define SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_
namespace syncer {
namespace syncable {
// For the most part, the sync engine treats version numbers as opaque values.
// However, there are parts of our code base that break this abstraction, and
// depend on the following two invariants:
//
// 1. CHANGES_VERSION is less than 0.
// 2. The server only issues positive version numbers.
//
// Breaking these abstractions makes some operations 10 times
// faster. If either of these invariants change, then those queries
// must be revisited.
enum {
CHANGES_VERSION = -1
};
#define CHANGES_VERSION_STRING "-1"
} // namespace syncable
} // namespace syncer
#endif // SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_