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/**
* @file Savepoint.h
* @ingroup SQLiteCpp
* @brief A Savepoint is a way to group multiple SQL statements into an atomic
* secured operation. Similar to a transaction while allowing child savepoints.
*
* Copyright (c) 2020 Kelvin Hammond (hammond.kelvin@gmail.com)
* Copyright (c) 2020-2025 Sebastien Rombauts (sebastien.rombauts@gmail.com)
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt or
* copy at http://opensource.org/licenses/MIT)
*/
#pragma once
#include <SQLiteCpp/SQLiteCppExport.h>
#include <SQLiteCpp/Exception.h>
namespace SQLite
{
// Forward declaration
class Database;
/**
* @brief RAII encapsulation of a SQLite Savepoint.
*
* SAVEPOINTs are a method of creating Transactions, similar to BEGIN and COMMIT,
* except that the SAVEPOINT and RELEASE commands are named and may be nested..
*
* Resource Acquisition Is Initialization (RAII) means that the Savepoint
* begins in the constructor and is rolled back in the destructor (unless committed before), 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.
*
* Caveats:
*
* 1) Calling COMMIT or committing a parent transaction or RELEASE on a parent
* savepoint will cause this savepoint to be released.
*
* 2) Calling ROLLBACK TO or rolling back a parent savepoint will cause this
* savepoint to be rolled back.
*
* 3) This savepoint is not saved to the database until this and all savepoints
* or transaction in the savepoint stack have been released or committed.
*
* See also: https://sqlite.org/lang_savepoint.html
*
* Thread-safety: a Savepoint 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 SQLITECPP_API Savepoint
{
public:
/**
* @brief Begins the SQLite savepoint
*
* @param[in] aDatabase the SQLite Database Connection
* @param[in] aName the name of the Savepoint
*
* Exception is thrown in case of error, then the Savepoint is NOT
* initiated.
*/
Savepoint(Database& aDatabase, const std::string& aName);
// Savepoint is non-copyable
Savepoint(const Savepoint&) = delete;
Savepoint& operator=(const Savepoint&) = delete;
/**
* @brief Safely rollback the savepoint if it has not been committed.
*/
~Savepoint();
/**
* @brief Commit and release the savepoint.
*/
void release();
/**
* @brief Rollback to the savepoint, but don't release it.
*/
void rollbackTo();
// @deprecated same as rollbackTo();
void rollback() { rollbackTo(); }
private:
Database& mDatabase; ///< Reference to the SQLite Database Connection
std::string msName; ///< Name of the Savepoint
bool mbReleased = false; ///< True when release has been called
};
} // namespace SQLite
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