src/app/qtlocalpeer/qtlockedfile.h

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2019  Mike Tzou (Chocobo1)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  *
  28 ****************************************************************************
  29 **
  30 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
  31 ** Contact: http://www.qt-project.org/legal
  32 **
  33 ** This file is part of the Qt Solutions component.
  34 **
  35 ** $QT_BEGIN_LICENSE:BSD$
  36 ** You may use this file under the terms of the BSD license as follows:
  37 **
  38 ** "Redistribution and use in source and binary forms, with or without
  39 ** modification, are permitted provided that the following conditions are
  40 ** met:
  41 **   * Redistributions of source code must retain the above copyright
  42 **     notice, this list of conditions and the following disclaimer.
  43 **   * Redistributions in binary form must reproduce the above copyright
  44 **     notice, this list of conditions and the following disclaimer in
  45 **     the documentation and/or other materials provided with the
  46 **     distribution.
  47 **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
  48 **     of its contributors may be used to endorse or promote products derived
  49 **     from this software without specific prior written permission.
  50 **
  51 **
  52 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  53 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  54 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  55 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  56 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  57 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  58 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  59 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  60 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  61 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  62 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  63 **
  64 ** $QT_END_LICENSE$
  65 **
  66 ****************************************************************************
  67 */
  68
  69 #pragma once
  70
  71 #include <QFile>
  72
  73 #ifdef Q_OS_WIN
  74 #include <QList>
  75 #include <QString>
  76 #endif
  77
  78 namespace QtLP_Private
  79 {
  80     class QtLockedFile final : public QFile
  81     {
  82     public:
  83         enum LockMode
  84         {
  85             NoLock = 0,
  86             ReadLock,
  87             WriteLock
  88         };
  89
  90         QtLockedFile();
  91         QtLockedFile(const QString &name);
  92         ~QtLockedFile();
  93
  94         bool open(OpenMode mode) override;
  95
  96         bool lock(LockMode mode, bool block = true);
  97         bool unlock();
  98         bool isLocked() const;
  99         LockMode lockMode() const;
 100
 101     private:
 102 #ifdef Q_OS_WIN
 103         Qt::HANDLE getMutexHandle(int idx, bool doCreate);
 104         bool waitMutex(Qt::HANDLE mutex, bool doBlock) const;
 105
 106         Qt::HANDLE m_writeMutex = nullptr;
 107         Qt::HANDLE m_readMutex = nullptr;
 108         QList<Qt::HANDLE> m_readMutexes;
 109         QString m_mutexName;
 110 #endif
 111
 112         LockMode m_lockMode = NoLock;
 113     };
 114 }