syncable_write_transaction.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_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_
6#define SYNC_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_
7
8#include "sync/base/sync_export.h"
9#include "sync/syncable/entry_kernel.h"
10#include "sync/syncable/syncable_base_transaction.h"
11
12namespace syncer {
13namespace syncable {
14
15SYNC_EXPORT extern const int64 kInvalidTransactionVersion;
16
17// Locks db in constructor, unlocks in destructor.
18class SYNC_EXPORT WriteTransaction : public BaseTransaction {
19 public:
20  WriteTransaction(const tracked_objects::Location& from_here,
21                   WriterTag writer, Directory* directory);
22
23  // Constructor used for getting back transaction version after making sync
24  // API changes to one model. If model is changed by the transaction,
25  // the new transaction version of the model and modified nodes will be saved
26  // in |transaction_version| upon destruction of the transaction. If model is
27  // not changed,  |transaction_version| will be kInvalidTransactionVersion.
28  WriteTransaction(const tracked_objects::Location& from_here,
29                   Directory* directory, int64* transaction_version);
30
31  virtual ~WriteTransaction();
32
33  void SaveOriginal(const EntryKernel* entry);
34
35 protected:
36  // Overridden by tests.
37  virtual void NotifyTransactionComplete(ModelTypeSet models_with_changes);
38
39 private:
40  friend class MutableEntry;
41
42  // Clears |mutations_|.
43  ImmutableEntryKernelMutationMap RecordMutations();
44
45  void UnlockAndNotify(const ImmutableEntryKernelMutationMap& mutations);
46
47  ModelTypeSet NotifyTransactionChangingAndEnding(
48      const ImmutableEntryKernelMutationMap& mutations);
49
50  // Increment versions of the models whose entries are modified and set the
51  // version on the changed entries.
52  void UpdateTransactionVersion(const std::vector<int64>& entry_changed);
53
54  // Only the original fields are filled in until |RecordMutations()|.
55  // We use a mutation map instead of a kernel set to avoid copying.
56  EntryKernelMutationMap mutations_;
57
58  // Stores new transaction version of changed model and nodes if model is
59  // indeed changed. kInvalidTransactionVersion otherwise. Not owned.
60  int64* transaction_version_;
61
62  DISALLOW_COPY_AND_ASSIGN(WriteTransaction);
63};
64
65}  // namespace syncable
66}  // namespace syncer
67
68#endif //  SYNC_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_
69