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// Copyright (c) 2009 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 CHROME_BROWSER_SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_
#define CHROME_BROWSER_SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_
#pragma once
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
#endif // CHROME_BROWSER_SYNC_SYNCABLE_SYNCABLE_CHANGES_VERSION_H_
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