Commit 1757217d authored by Oswald Buddenhagen's avatar Oswald Buddenhagen
Browse files

add Utils::SaveFile: class for atomic saving of files

inspired by KSaveFile
parent fd97a4b8
/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (info@qt.nokia.com)
**
**
** GNU Lesser General Public License Usage
**
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this file.
** Please review the following information to ensure the GNU Lesser General
** Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** Other Usage
**
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**************************************************************************/
#include "savefile.h"
#include "qtcassert.h"
#include <QtCore/QFileInfo>
#include <QtCore/QTemporaryFile>
namespace Utils {
SaveFile::SaveFile(const QString &filename)
{
m_finalFileName = filename;
m_finalized = false;
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;
if (ofi.exists())
setPermissions(ofi.permissions()); // Ignore errors
return true;
}
void SaveFile::rollback()
{
remove();
m_finalized = true;
}
bool SaveFile::commit()
{
QTC_ASSERT(!m_finalized, return false);
m_finalized = true;
close();
if (error() != NoError) {
remove();
return false;
}
QString bakname = m_finalFileName + QLatin1Char('~');
QFile::remove(bakname); // Kill old backup
QFile::rename(m_finalFileName, bakname); // Backup current file
if (!rename(m_finalFileName)) { // Replace current file
QFile::rename(bakname, m_finalFileName); // Rollback to current file
return false;
}
if (!m_backup)
QFile::remove(bakname);
return true;
}
} // namespace Utils
/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (info@qt.nokia.com)
**
**
** GNU Lesser General Public License Usage
**
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this file.
** Please review the following information to ensure the GNU Lesser General
** Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** Other Usage
**
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**************************************************************************/
#ifndef SAVEFILE_H
#define SAVEFILE_H
#include "utils_global.h"
#include <QtCore/QTemporaryFile>
namespace Utils {
class QTCREATOR_UTILS_EXPORT SaveFile : public QTemporaryFile
{
public:
explicit SaveFile(const QString &filename);
virtual ~SaveFile();
bool open(OpenMode flags = QIODevice::WriteOnly);
void rollback();
bool commit();
void setBackup(bool backup) { m_backup = backup; }
private:
Q_DISABLE_COPY(SaveFile)
QString m_finalFileName;
bool m_finalized;
bool m_backup;
};
}
#endif // SAVEFILE_H
......@@ -33,6 +33,7 @@ SOURCES += $$PWD/environment.cpp \
$$PWD/savedaction.cpp \
$$PWD/submiteditorwidget.cpp \
$$PWD/synchronousprocess.cpp \
$$PWD/savefile.cpp \
$$PWD/submitfieldwidget.cpp \
$$PWD/consoleprocess.cpp \
$$PWD/uncommentselection.cpp \
......@@ -122,6 +123,7 @@ HEADERS += $$PWD/environment.h \
$$PWD/abstractprocess.h \
$$PWD/consoleprocess.h \
$$PWD/synchronousprocess.h \
$$PWD/savefile.h \
$$PWD/submitfieldwidget.h \
$$PWD/uncommentselection.h \
$$PWD/parameteraction.h \
......
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