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_SYNCABLE_SERVICE_H_
6#define SYNC_API_SYNCABLE_SERVICE_H_
7
8#include <vector>
9
10#include "base/callback.h"
11#include "base/compiler_specific.h"
12#include "base/memory/scoped_ptr.h"
13#include "base/memory/weak_ptr.h"
14#include "sync/api/attachments/attachment_store.h"
15#include "sync/api/sync_change_processor.h"
16#include "sync/api/sync_data.h"
17#include "sync/api/sync_error.h"
18#include "sync/api/sync_merge_result.h"
19#include "sync/base/sync_export.h"
20#include "sync/internal_api/public/base/model_type.h"
21
22namespace syncer {
23
24class SyncErrorFactory;
25
26// TODO(zea): remove SupportsWeakPtr in favor of having all SyncableService
27// implementers provide a way of getting a weak pointer to themselves.
28// See crbug.com/100114.
29class SYNC_EXPORT SyncableService
30    : public SyncChangeProcessor,
31      public base::SupportsWeakPtr<SyncableService> {
32 public:
33  // A StartSyncFlare is useful when your SyncableService has a need for sync
34  // to start ASAP, typically because a local change event has occurred but
35  // MergeDataAndStartSyncing hasn't been called yet, meaning you don't have a
36  // SyncChangeProcessor. The sync subsystem will respond soon after invoking
37  // Run() on your flare by calling MergeDataAndStartSyncing. The ModelType
38  // parameter is included so that the recieving end can track usage and timing
39  // statistics, make optimizations or tradeoffs by type, etc.
40  typedef base::Callback<void(ModelType)> StartSyncFlare;
41
42  // Informs the service to begin syncing the specified synced datatype |type|.
43  // The service should then merge |initial_sync_data| into it's local data,
44  // calling |sync_processor|'s ProcessSyncChanges as necessary to reconcile the
45  // two. After this, the SyncableService's local data should match the server
46  // data, and the service should be ready to receive and process any further
47  // SyncChange's as they occur.
48  // Returns: a SyncMergeResult whose error field reflects whether an error
49  //          was encountered while merging the two models. The merge result
50  //          may also contain optional merge statistics.
51  virtual SyncMergeResult MergeDataAndStartSyncing(
52      ModelType type,
53      const SyncDataList& initial_sync_data,
54      scoped_ptr<SyncChangeProcessor> sync_processor,
55      scoped_ptr<SyncErrorFactory> error_handler) = 0;
56
57  // Stop syncing the specified type and reset state.
58  virtual void StopSyncing(ModelType type) = 0;
59
60  // SyncChangeProcessor interface.
61  // Process a list of new SyncChanges and update the local data as necessary.
62  // Returns: A default SyncError (IsSet() == false) if no errors were
63  //          encountered, and a filled SyncError (IsSet() == true)
64  //          otherwise.
65  virtual SyncError ProcessSyncChanges(
66      const tracked_objects::Location& from_here,
67      const SyncChangeList& change_list) OVERRIDE = 0;
68
69  // Returns AttachmentStore used by datatype. Attachment store is used by sync
70  // when uploading or downloading attachments.
71  // GetAttachmentStore is called right before MergeDataAndStartSyncing. If at
72  // that time GetAttachmentStore returns NULL then datatype is considered not
73  // using attachments and all attempts to upload/download attachments will
74  // fail. Default implementation returns NULL. Datatype that uses sync
75  // attachemnts should create attachment store and implement GetAttachmentStore
76  // to return pointer to it.
77  virtual scoped_refptr<AttachmentStore> GetAttachmentStore();
78
79 protected:
80  virtual ~SyncableService();
81};
82
83}  // namespace syncer
84
85#endif  // SYNC_API_SYNCABLE_SERVICE_H_
86