sync_data.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
1// Copyright 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/base/sync_export.h"
14#include "sync/internal_api/public/base/model_type.h"
15#include "sync/internal_api/public/util/immutable.h"
16
17namespace sync_pb {
18class EntitySpecifics;
19class SyncEntity;
20}  // namespace sync_pb
21
22namespace syncer {
23
24// A light-weight container for immutable sync data. Pass-by-value and storage
25// in STL containers are supported and encouraged if helpful.
26class SYNC_EXPORT SyncData {
27 public:
28  // Creates an empty and invalid SyncData.
29  SyncData();
30   ~SyncData();
31
32   // Default copy and assign welcome.
33
34  // Helper methods for creating SyncData objects for local data.
35  // The sync tag must be a string unique to this datatype and is used as a node
36  // identifier server-side.
37  // For deletes: |datatype| must specify the datatype who node is being
38  // deleted.
39  // For adds/updates: the specifics must be valid and the non-unique title (can
40  // be the same as sync tag) must be specfied.
41  // Note: the non_unique_title is primarily for debug purposes, and will be
42  // overwritten if the datatype is encrypted.
43  static SyncData CreateLocalDelete(
44      const std::string& sync_tag,
45      ModelType datatype);
46  static SyncData CreateLocalData(
47      const std::string& sync_tag,
48      const std::string& non_unique_title,
49      const sync_pb::EntitySpecifics& specifics);
50
51  // Helper method for creating SyncData objects originating from the syncer.
52  static SyncData CreateRemoteData(
53      int64 id, const sync_pb::EntitySpecifics& specifics);
54
55  // Whether this SyncData holds valid data. The only way to have a SyncData
56  // without valid data is to use the default constructor.
57  bool IsValid() const;
58
59  // Return the datatype we're holding information about. Derived from the sync
60  // datatype specifics.
61  ModelType GetDataType() const;
62
63  // Return the current sync datatype specifics.
64  const sync_pb::EntitySpecifics& GetSpecifics() const;
65
66  // Returns the value of the unique client tag. This is only set for data going
67  // TO the syncer, not coming from.
68  const std::string& GetTag() const;
69
70  // Returns the non unique title (for debugging). Currently only set for data
71  // going TO the syncer, not from.
72  const std::string& GetTitle() const;
73
74  // Should only be called by sync code when IsLocal() is false.
75  int64 GetRemoteId() const;
76
77  // Whether this sync data is for local data or data coming from the syncer.
78  bool IsLocal() const;
79
80  std::string ToString() const;
81
82  // TODO(zea): Query methods for other sync properties: parent, successor, etc.
83
84 private:
85  // Necessary since we forward-declare sync_pb::SyncEntity; see
86  // comments in immutable.h.
87  struct ImmutableSyncEntityTraits {
88    typedef sync_pb::SyncEntity* Wrapper;
89
90    static void InitializeWrapper(Wrapper* wrapper);
91
92    static void DestroyWrapper(Wrapper* wrapper);
93
94    static const sync_pb::SyncEntity& Unwrap(const Wrapper& wrapper);
95
96    static sync_pb::SyncEntity* UnwrapMutable(Wrapper* wrapper);
97
98    static void Swap(sync_pb::SyncEntity* t1, sync_pb::SyncEntity* t2);
99  };
100
101  typedef Immutable<sync_pb::SyncEntity, ImmutableSyncEntityTraits>
102      ImmutableSyncEntity;
103
104  // Clears |entity|.
105  SyncData(int64 id, sync_pb::SyncEntity* entity);
106
107  // Whether this SyncData holds valid data.
108  bool is_valid_;
109
110  // Equal to kInvalidId iff this is local.
111  int64 id_;
112
113  // The actual shared sync entity being held.
114  ImmutableSyncEntity immutable_entity_;
115};
116
117// gmock printer helper.
118void PrintTo(const SyncData& sync_data, std::ostream* os);
119
120typedef std::vector<SyncData> SyncDataList;
121
122}  // namespace syncer
123
124#endif  // SYNC_API_SYNC_DATA_H_
125