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
|
/**
* @file Transaction.h
* @ingroup SQLiteCpp
* @brief A Transaction is way to group multiple SQL statements into an atomic secured operation.
*
* Copyright (c) 2012-2021 Sebastien Rombauts ([email protected])
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
* or copy at http://opensource.org/licenses/MIT)
*/
#pragma once
#include <SQLiteCpp/Exception.h>
namespace SQLite
{
// Forward declaration
class Database;
/**
* @brief Transaction behaviors when opening an SQLite transaction.
* Names correspond directly to the behavior.
*/
enum class TransactionBehavior {
DEFERRED,
IMMEDIATE,
EXCLUSIVE,
};
/**
* @brief RAII encapsulation of a SQLite Transaction.
*
* A Transaction is a way to group multiple SQL statements into an atomic secured operation;
* either it succeeds, with all the changes committed to the database file,
* or if it fails, all the changes are rolled back to the initial state.
*
* Resource Acquisition Is Initialization (RAII) means that the Transaction
* begins in the constructor and is rollbacked in the destructor, so that there is
* no need to worry about memory management or the validity of the underlying SQLite Connection.
*
* This method also offers big performances improvements compared to individually executed statements.
*
* Thread-safety: a Transaction object shall not be shared by multiple threads, because :
* 1) in the SQLite "Thread Safe" mode, "SQLite can be safely used by multiple threads
* provided that no single database connection is used simultaneously in two or more threads."
* 2) the SQLite "Serialized" mode is not supported by SQLiteC++,
* because of the way it shares the underling SQLite precompiled statement
* in a custom shared pointer (See the inner class "Statement::Ptr").
*/
class Transaction
{
public:
/**
* @brief Begins the SQLite transaction using the default transaction behavior.
*
* @param[in] aDatabase the SQLite Database Connection
*
* Exception is thrown in case of error, then the Transaction is NOT initiated.
*/
explicit Transaction(Database& aDatabase);
/**
* @brief Begins the SQLite transaction with the specified behavior.
*
* @param[in] aDatabase the SQLite Database Connection
* @param[in] behavior the requested transaction behavior
*
* Exception is thrown in case of error, then the Transaction is NOT initiated.
*/
explicit Transaction(Database& aDatabase, TransactionBehavior behavior);
// Transaction is non-copyable
Transaction(const Transaction&) = delete;
Transaction& operator=(const Transaction&) = delete;
/**
* @brief Safely rollback the transaction if it has not been committed.
*/
~Transaction();
/**
* @brief Commit the transaction.
*/
void commit();
private:
Database& mDatabase; ///< Reference to the SQLite Database Connection
bool mbCommited; ///< True when commit has been called
};
} // namespace SQLite
|
