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/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://www.qt.io/licensing. For further information
** use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/
#include "savefile.h"
#include "qtcassert.h"
#include "fileutils.h"
#ifdef Q_OS_WIN
# include <windows.h>
#else
# include <unistd.h>
# include <sys/stat.h>
#endif
namespace Utils {
QFile::Permissions SaveFile::m_umask = 0;
SaveFile::SaveFile(const QString &filename) :
m_finalFileName(filename), m_finalized(true), m_backup(false)
{
}
SaveFile::~SaveFile()
{
QTC_ASSERT(m_finalized, rollback());
}
bool SaveFile::open(OpenMode flags)
{
QTC_ASSERT(!m_finalFileName.isEmpty() && fileName().isEmpty(), return false);
QFile ofi(m_finalFileName);
// Check whether the existing file is writable
if (ofi.exists() && !ofi.open(QIODevice::ReadWrite)) {
setErrorString(ofi.errorString());
return false;
}
setAutoRemove(false);
setFileTemplate(m_finalFileName);
if (!QTemporaryFile::open(flags))
return false;
m_finalized = false; // needs clean up in the end
if (ofi.exists()) {
setPermissions(ofi.permissions()); // Ignore errors
} else {
Permissions permAll = QFile::ReadOwner
| QFile::ReadGroup
| QFile::ReadOther
| QFile::WriteOwner
| QFile::WriteGroup
| QFile::WriteOther;
// set permissions with respect to the current umask
setPermissions(permAll & ~m_umask);
}
return true;
}
void SaveFile::rollback()
{
remove();
m_finalized = true;
}
bool SaveFile::commit()
{
QTC_ASSERT(!m_finalized, return false);
m_finalized = true;
if (!flush()) {
remove();
return false;
}
#ifdef Q_OS_WIN
FlushFileBuffers(reinterpret_cast<HANDLE>(handle()));
#elif _POSIX_SYNCHRONIZED_IO > 0
fdatasync(handle());
#else
fsync(handle());
#endif
close();
if (error() != NoError) {
remove();
return false;
}
QString finalFileName
= FileUtils::resolveSymlinks(FileName::fromString(m_finalFileName)).toString();
QString bakname = finalFileName + QLatin1Char('~');
QFile::remove(bakname); // Kill old backup
QFile::rename(finalFileName, bakname); // Backup current file
if (!rename(finalFileName)) { // Replace current file
QFile::rename(bakname, finalFileName); // Rollback to current file
return false;
}
if (!m_backup)
QFile::remove(bakname);
return true;
}
void SaveFile::initializeUmask()
{
#ifdef Q_OS_WIN
m_umask = QFile::WriteGroup | QFile::WriteOther;
#else
// Get the current process' file creation mask (umask)
// umask() is not thread safe so this has to be done by single threaded
// application initialization
mode_t mask = umask(0); // get current umask
umask(mask); // set it back
m_umask = ((mask & S_IRUSR) ? QFile::ReadOwner : QFlags<QFile::Permission>(0))
| ((mask & S_IWUSR) ? QFile::WriteOwner : QFlags<QFile::Permission>(0))
| ((mask & S_IXUSR) ? QFile::ExeOwner : QFlags<QFile::Permission>(0))
| ((mask & S_IRGRP) ? QFile::ReadGroup : QFlags<QFile::Permission>(0))
| ((mask & S_IWGRP) ? QFile::WriteGroup : QFlags<QFile::Permission>(0))
| ((mask & S_IXGRP) ? QFile::ExeGroup : QFlags<QFile::Permission>(0))
| ((mask & S_IROTH) ? QFile::ReadOther : QFlags<QFile::Permission>(0))
| ((mask & S_IWOTH) ? QFile::WriteOther : QFlags<QFile::Permission>(0))
| ((mask & S_IXOTH) ? QFile::ExeOther : QFlags<QFile::Permission>(0));
#endif
}
} // namespace Utils
|
