Files
qelectrotech-source-mirror/sources/utils/syncfolder.h
T
ispyisail 7e96bb51d2 Sync the folder after saving, and save from the command line through a temporary file
QSaveFile writes a new file, forces it to disk and renames it over the
old one, but does not force the folder to disk. On ext4 or XFS a power
cut soon after a save can then lose the rename: the previous file comes
back, or none. QET::syncFolderOf() now syncs the folder after every
project, symbol and title block save (QET::writeXmlText()) and every
.qetz save (QetZip::write()). Nothing to do on Windows.

--resave and --set-titleblock wrote a .qet straight over the output file
(QFile, truncate, write): a run stopped part-way left half a project.
They now write through QET::writeXmlText() like the GUI's save. On
Windows their .qet now has LF line ends, as the GUI writes.

Checked with strace on --resave: fdatasync of the new file, linkat into
place, fsync of the folder. The .qet written is byte-identical to before.
ctest 106/106.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-16 08:23:31 +13:00

55 lines
1.6 KiB
C++

/*
Copyright 2006-2026 The QElectroTech Team
This file is part of QElectroTech.
QElectroTech 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 2 of the License, or
(at your option) any later version.
QElectroTech 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 QElectroTech. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SYNCFOLDER_H
#define SYNCFOLDER_H
#include <QFile>
#include <QFileInfo>
#include <QString>
#ifndef Q_OS_WIN
#include <fcntl.h>
#include <unistd.h>
#endif
namespace QET {
/**
Force to disk the folder holding @p file_path, once
QSaveFile::commit() renamed a new file into it. QSaveFile syncs the
file it wrote but not the folder, and on some file systems (ext4,
XFS) a power cut soon after can then lose the rename: the previous
file comes back, or none. Does nothing on Windows, where a folder
cannot be synced this way.
*/
inline void syncFolderOf(const QString &file_path)
{
#ifndef Q_OS_WIN
const QByteArray folder = QFile::encodeName(QFileInfo(file_path).absolutePath());
const int fd = ::open(folder.constData(), O_RDONLY | O_DIRECTORY | O_CLOEXEC);
if (fd >= 0) {
::fsync(fd);
::close(fd);
}
#else
Q_UNUSED(file_path)
#endif
}
}
#endif // SYNCFOLDER_H