1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
/**
* Copyright (C) 2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/disallow_copying.h"
#include "mongo/base/status.h"
#include "mongo/base/status_with.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/db/record_id.h"
#include "mongo/db/repl/oplog_interface.h"
#include "mongo/stdx/functional.h"
namespace mongo {
namespace repl {
class RollBackLocalOperations {
MONGO_DISALLOW_COPYING(RollBackLocalOperations);
public:
/**
* Type of function to roll back an operation or process it for future use.
* It can return any status except ErrorCodes::NoSuchKey. See onRemoteOperation().
*/
using RollbackOperationFn = stdx::function<Status (const BSONObj&)>;
using RollbackCommonPoint = std::pair<Timestamp, RecordId>;
/**
* Initializes rollback processor with a valid local oplog.
* Whenever we encounter an operation in the local oplog that has to be rolled back,
* we will pass it to 'rollbackOperation'.
*/
RollBackLocalOperations(const OplogInterface& localOplog,
const RollbackOperationFn& rollbackOperation);
virtual ~RollBackLocalOperations() = default;
/**
* Process single remote operation.
* Returns ErrorCodes::NoSuchKey if common point has not been found and
* additional operations have to be read from the remote oplog.
*/
StatusWith<RollbackCommonPoint> onRemoteOperation(const BSONObj& operation);
private:
std::unique_ptr<OplogInterface::Iterator> _localOplogIterator;
RollbackOperationFn _rollbackOperation;
OplogInterface::Iterator::Value _localOplogValue;
unsigned long long _scanned;
};
/**
* Rolls back every operation in the local oplog that is not in the remote oplog, in reverse
* order.
*
* Whenever we encounter an operation in the local oplog that has to be rolled back,
* we will pass it to 'rollbackOperation' starting with the most recent operation.
* It is up to 'rollbackOperation' to roll back this operation immediately or
* process it for future use.
*/
StatusWith<RollBackLocalOperations::RollbackCommonPoint> syncRollBackLocalOperations(
const OplogInterface& localOplog,
const OplogInterface& remoteOplog,
const RollBackLocalOperations::RollbackOperationFn& rollbackOperation);
} // namespace repl
} // namespace mongo
|
