sync_data.h revision 5821806d5e7f356e8fa4b058a389a808ea183019 
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.
4
5#ifndef SYNC_API_SYNC_DATA_H_
6#define SYNC_API_SYNC_DATA_H_
7
8#include <iosfwd>
9#include <string>
10#include <vector>
11
12#include "base/basictypes.h"
13#include "sync/internal_api/public/base/model_type.h"
14#include "sync/internal_api/public/util/immutable.h"
15
16namespace sync_pb {
17class EntitySpecifics;
18class SyncEntity;
19}  // namespace sync_pb
20
21namespace syncer {
22
23// A light-weight container for immutable sync data. Pass-by-value and storage
24// in STL containers are supported and encouraged if helpful.
25class SyncData {
26 public:
27  // Creates an empty and invalid SyncData.
28  SyncData();
29   ~SyncData();
30
31   // Default copy and assign welcome.
32
33  // Helper methods for creating SyncData objects for local data.
34  // The sync tag must be a string unique to this datatype and is used as a node
35  // identifier server-side.
36  // For deletes: |datatype| must specify the datatype who node is being
37  // deleted.
38  // For adds/updates: the specifics must be valid and the non-unique title (can
39  // be the same as sync tag) must be specfied.
40  // Note: the non_unique_title is primarily for debug purposes, and will be
41  // overwritten if the datatype is encrypted.
42  static SyncData CreateLocalDelete(
43      const std::string& sync_tag,
44      ModelType datatype);
45  static SyncData CreateLocalData(
46      const std::string& sync_tag,
47      const std::string& non_unique_title,
48      const sync_pb::EntitySpecifics& specifics);
49
50  // Helper method for creating SyncData objects originating from the syncer.
51  static SyncData CreateRemoteData(
52      int64 id, const sync_pb::EntitySpecifics& specifics);
53
54  // Whether this SyncData holds valid data. The only way to have a SyncData
55  // without valid data is to use the default constructor.
56  bool IsValid() const;
57
58  // Return the datatype we're holding information about. Derived from the sync
59  // datatype specifics.
60  ModelType GetDataType() const;
61
62  // Return the current sync datatype specifics.
63  const sync_pb::EntitySpecifics& GetSpecifics() const;
64
65  // Returns the value of the unique client tag. This is only set for data going
66  // TO the syncer, not coming from.
67  const std::string& GetTag() const;
68
69  // Returns the non unique title (for debugging). Currently only set for data
70  // going TO the syncer, not from.
71  const std::string& GetTitle() const;
72
73  // Should only be called by sync code when IsLocal() is false.
74  int64 GetRemoteId() const;
75
76  // Whether this sync data is for local data or data coming from the syncer.
77  bool IsLocal() const;
78
79  std::string ToString() const;
80
81  // TODO(zea): Query methods for other sync properties: parent, successor, etc.
82
83 private:
84  // Necessary since we forward-declare sync_pb::SyncEntity; see
85  // comments in immutable.h.
86  struct ImmutableSyncEntityTraits {
87    typedef sync_pb::SyncEntity* Wrapper;
88
89    static void InitializeWrapper(Wrapper* wrapper);
90
91    static void DestroyWrapper(Wrapper* wrapper);
92
93    static const sync_pb::SyncEntity& Unwrap(const Wrapper& wrapper);
94
95    static sync_pb::SyncEntity* UnwrapMutable(Wrapper* wrapper);
96
97    static void Swap(sync_pb::SyncEntity* t1, sync_pb::SyncEntity* t2);
98  };
99
100  typedef Immutable<sync_pb::SyncEntity, ImmutableSyncEntityTraits>
101      ImmutableSyncEntity;
102
103  // Clears |entity|.
104  SyncData(int64 id, sync_pb::SyncEntity* entity);
105
106  // Whether this SyncData holds valid data.
107  bool is_valid_;
108
109  // Equal to kInvalidId iff this is local.
110  int64 id_;
111
112  // The actual shared sync entity being held.
113  ImmutableSyncEntity immutable_entity_;
114};
115
116// gmock printer helper.
117void PrintTo(const SyncData& sync_data, std::ostream* os);
118
119}  // namespace syncer
120
121#endif  // SYNC_API_SYNC_DATA_H_
122