122 lines
3.6 KiB
C++
122 lines
3.6 KiB
C++
/****************************************************************************
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**
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** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
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** All rights reserved.
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** Contact: Nokia Corporation (qt-info@nokia.com)
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**
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** This file is part of a Qt Solutions component.
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**
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** Commercial Usage
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** Licensees holding valid Qt Commercial licenses may use this file in
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** accordance with the Qt Solutions Commercial License Agreement provided
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** with the Software or, alternatively, in accordance with the terms
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** contained in a written agreement between you and Nokia.
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**
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** GNU Lesser General Public License Usage
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** Alternatively, this file may be used under the terms of the GNU Lesser
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** General Public License version 2.1 as published by the Free Software
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** Foundation and appearing in the file LICENSE.LGPL included in the
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** packaging of this file. Please review the following information to
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** ensure the GNU Lesser General Public License version 2.1 requirements
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** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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**
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** In addition, as a special exception, Nokia gives you certain
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** additional rights. These rights are described in the Nokia Qt LGPL
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** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
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** package.
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**
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** GNU General Public License Usage
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** Alternatively, this file may be used under the terms of the GNU
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** General Public License version 3.0 as published by the Free Software
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** Foundation and appearing in the file LICENSE.GPL included in the
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** packaging of this file. Please review the following information to
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** ensure the GNU General Public License version 3.0 requirements will be
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** met: http://www.gnu.org/copyleft/gpl.html.
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**
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** Please note Third Party Software included with Qt Solutions may impose
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** additional restrictions and it is the user's responsibility to ensure
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** that they have met the licensing requirements of the GPL, LGPL, or Qt
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** Solutions Commercial license and the relevant license of the Third
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** Party Software they are using.
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**
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** If you are unsure which license is appropriate for your use, please
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** contact Nokia at qt-info@nokia.com.
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**
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****************************************************************************/
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include "qtlockedfile.h"
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bool QtLockedFile::lock(LockMode mode, bool block)
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{
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if (!isOpen()) {
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qWarning("QtLockedFile::lock(): file is not opened");
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return false;
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}
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if (mode == NoLock)
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return unlock();
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if (mode == m_lock_mode)
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return true;
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if (m_lock_mode != NoLock)
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unlock();
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struct flock fl;
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fl.l_whence = SEEK_SET;
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fl.l_start = 0;
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fl.l_len = 0;
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fl.l_type = (mode == ReadLock) ? F_RDLCK : F_WRLCK;
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int cmd = block ? F_SETLKW : F_SETLK;
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int ret = fcntl(handle(), cmd, &fl);
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if (ret == -1) {
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if (errno != EINTR && errno != EAGAIN)
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qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
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return false;
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}
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m_lock_mode = mode;
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return true;
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}
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bool QtLockedFile::unlock()
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{
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if (!isOpen()) {
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qWarning("QtLockedFile::unlock(): file is not opened");
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return false;
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}
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if (!isLocked())
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return true;
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struct flock fl;
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fl.l_whence = SEEK_SET;
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fl.l_start = 0;
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fl.l_len = 0;
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fl.l_type = F_UNLCK;
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int ret = fcntl(handle(), F_SETLKW, &fl);
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if (ret == -1) {
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qWarning("QtLockedFile::lock(): fcntl: %s", strerror(errno));
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return false;
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}
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m_lock_mode = NoLock;
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return true;
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}
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QtLockedFile::~QtLockedFile()
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{
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if (isOpen())
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unlock();
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}
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