summaryrefslogtreecommitdiffstats
path: root/chromium/sync/engine/conflict_resolver.h
blob: 4ca614ddac68da7dc8b5e8ac62a4e47c3a313150 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
// 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.
//
// A class that watches the syncer and attempts to resolve any conflicts that
// occur.

#ifndef SYNC_ENGINE_CONFLICT_RESOLVER_H_
#define SYNC_ENGINE_CONFLICT_RESOLVER_H_

#include <set>

#include "base/basictypes.h"
#include "base/gtest_prod_util.h"
#include "sync/engine/syncer_types.h"

namespace syncer {

namespace syncable {
class Id;
class WriteTransaction;
}  // namespace syncable

class Cryptographer;

namespace sessions {
class StatusController;
}  // namespace sessions

class ConflictResolver {
  friend class SyncerTest;
  FRIEND_TEST_ALL_PREFIXES(SyncerTest,
                           ConflictResolverMergeOverwritesLocalEntry);
 public:
  // Enumeration of different conflict resolutions. Used for histogramming.
  enum SimpleConflictResolutions {
    OVERWRITE_LOCAL,           // Resolved by overwriting local changes.
    OVERWRITE_SERVER,          // Resolved by overwriting server changes.
    UNDELETE,                  // Resolved by undeleting local item.
    IGNORE_ENCRYPTION,         // Resolved by ignoring an encryption-only server
                               // change.
    NIGORI_MERGE,              // Resolved by merging nigori nodes.
    CHANGES_MATCH,             // Resolved by ignoring both local and server
                               // changes because they matched.
    CONFLICT_RESOLUTION_SIZE,
  };

  ConflictResolver();
  ~ConflictResolver();
  // Called by the syncer at the end of a update/commit cycle.
  // Returns true if the syncer should try to apply its updates again.
  void ResolveConflicts(syncable::WriteTransaction* trans,
                        const Cryptographer* cryptographer,
                        const std::set<syncable::Id>& simple_conflict_ids,
                        sessions::StatusController* status);

 private:
  void ProcessSimpleConflict(
      syncable::WriteTransaction* trans,
      const syncable::Id& id,
      const Cryptographer* cryptographer,
      sessions::StatusController* status);

  DISALLOW_COPY_AND_ASSIGN(ConflictResolver);
};

}  // namespace syncer

#endif  // SYNC_ENGINE_CONFLICT_RESOLVER_H_