diff options
author | Oswald Buddenhagen <oswald.buddenhagen@nokia.com> | 2011-03-30 12:07:47 +0200 |
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committer | Oswald Buddenhagen <oswald.buddenhagen@nokia.com> | 2011-04-18 14:10:12 +0200 |
commit | 1757217da654962fd4152c40889f1de66e976e34 (patch) | |
tree | d0fc6417722cd73dc9c52eb33c9c29a86644c11a /src/libs/utils/savefile.cpp | |
parent | fd97a4b8bc4d06accf3dcb60f28ace1621f579d7 (diff) |
add Utils::SaveFile: class for atomic saving of files
inspired by KSaveFile
Diffstat (limited to 'src/libs/utils/savefile.cpp')
-rw-r--r-- | src/libs/utils/savefile.cpp | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/libs/utils/savefile.cpp b/src/libs/utils/savefile.cpp new file mode 100644 index 00000000000..7c0d9704b4d --- /dev/null +++ b/src/libs/utils/savefile.cpp @@ -0,0 +1,106 @@ +/************************************************************************** +** +** 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 |