syncable_base_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_BASE_TRANSACTION_H_
6#define SYNC_SYNCABLE_SYNCABLE_BASE_TRANSACTION_H_
7
8#include "base/location.h"
9#include "sync/base/sync_export.h"
10#include "sync/syncable/syncable_id.h"
11
12namespace syncer {
13namespace syncable {
14
15class Directory;
16
17// A WriteTransaction has a writer tag describing which body of code is doing
18// the write. This is defined up here since WriteTransactionInfo also contains
19// one.
20enum WriterTag {
21  INVALID,
22  SYNCER,
23  AUTHWATCHER,
24  UNITTEST,
25  VACUUM_AFTER_SAVE,
26  HANDLE_SAVE_FAILURE,
27  PURGE_ENTRIES,
28  SYNCAPI,
29};
30
31// Make sure to update this if you update WriterTag.
32std::string WriterTagToString(WriterTag writer_tag);
33
34class SYNC_EXPORT BaseTransaction {
35 public:
36  Directory* directory() const;
37  Id root_id() const;
38
39  virtual ~BaseTransaction();
40
41  // This should be called when a database corruption is detected and there is
42  // no way for us to recover short of wiping the database clean. When this is
43  // called we set a bool in the transaction. The caller has to unwind the
44  // stack. When the destructor for the transaction is called it acts upon the
45  // bool and calls the Directory to handle the unrecoverable error.
46  void OnUnrecoverableError(const tracked_objects::Location& location,
47                            const std::string& message);
48
49  bool unrecoverable_error_set() const;
50
51 protected:
52  BaseTransaction(const tracked_objects::Location& from_here,
53                  const char* name,
54                  WriterTag writer,
55                  Directory* directory);
56
57  void Lock();
58  void Unlock();
59
60  // This should be called before unlocking because it calls the Direcotry's
61  // OnUnrecoverableError method which is not protected by locks and could
62  // be called from any thread. Holding the transaction lock ensures only one
63  // thread could call the method at a time.
64  void HandleUnrecoverableErrorIfSet();
65
66  const tracked_objects::Location from_here_;
67  const char* const name_;
68  WriterTag writer_;
69  Directory* const directory_;
70
71  // Error information.
72  bool unrecoverable_error_set_;
73  tracked_objects::Location unrecoverable_error_location_;
74  std::string unrecoverable_error_msg_;
75
76 private:
77  friend class Entry;
78  DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
79};
80
81}  // namespace syncable
82}  // namespace syncer
83
84#endif  // SYNC_SYNCABLE_SYNCABLE_BASE_TRANSACTION_H_
85