Copyright (C) 2012-2020 Rudolf Cardinal (firstname.lastname@example.org).
This file is part of CamCOPS.
CamCOPS is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
CamCOPS 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with CamCOPS. If not, see <http://www.gnu.org/licenses/>.
// Represents an SQL transaction.
// In general, consider AVOIDING this and using DbNestableTransaction
// instead. DbTransaction uses BEGIN TRANSACTION/COMMIT/ROLLBACK, and so
// if you accidentally nest it, things go wrong.
// DbNestableTransaction uses SAVEPOINT x/RELEASE x/ROLLBACK TO SAVEPOINT x
// instead, which is safely nestable as long as x is transaction-specific,
// and RELEASE behaves like COMMIT when it reaches the top level.
// Create the transaction. It starts in a "successful" state.
// When the transaction is destroyed, it commits or rolls back depending
// on whether it's been told of failure or not.
// Mark the transaction as a failure.
// Mark the transaction as successful.
// Our database manager.
// Have we failed?