filemanager.h Example File
network/torrent/filemanager.h

 /****************************************************************************
 **
 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** 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 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.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3.0 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
 ** If you have questions regarding the use of this file, please contact
 ** Nokia at qt-info@nokia.com.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #ifndef FILEMANAGER_H
 #define FILEMANAGER_H

 #include <QBitArray>
 #include <QList>
 #include <QMutex>
 #include <QThread>
 #include <QWaitCondition>

 #include "metainfo.h"

 class QByteArray;
 class QFile;
 class QTimerEvent;

 class FileManager : public QThread
 {
     Q_OBJECT

 public:
     FileManager(QObject *parent = 0);
     virtual ~FileManager();

     inline void setMetaInfo(const MetaInfo &info) { metaInfo = info; }
     inline void setDestinationFolder(const QString &directory) { destinationPath = directory; }

     int read(int pieceIndex, int offset, int length);
     void write(int pieceIndex, int offset, const QByteArray &data);
     void verifyPiece(int pieceIndex);
     inline qint64 totalSize() const { return totalLength; }

     inline int pieceCount() const { return numPieces; }
     int pieceLengthAt(int pieceIndex) const;

     QBitArray completedPieces() const;
     void setCompletedPieces(const QBitArray &pieces);

     QString errorString() const;

 public slots:
     void startDataVerification();

 signals:
     void dataRead(int id, int pieceIndex, int offset, const QByteArray &data);
     void error();
     void verificationProgress(int percent);
     void verificationDone();
     void pieceVerified(int pieceIndex, bool verified);

 protected:
     void run();

 private slots:
     bool verifySinglePiece(int pieceIndex);
     void wakeUp();

 private:
     bool generateFiles();
     QByteArray readBlock(int pieceIndex, int offset, int length);
     bool writeBlock(int pieceIndex, int offset, const QByteArray &data);
     void verifyFileContents();

     struct WriteRequest {
         int pieceIndex;
         int offset;
         QByteArray data;
     };
     struct ReadRequest {
         int pieceIndex;
         int offset;
         int length;
         int id;
     };

     QString errString;
     QString destinationPath;
     MetaInfo metaInfo;
     QList<QFile *> files;
     QList<QByteArray> sha1s;
     QBitArray verifiedPieces;

     bool newFile;
     int pieceLength;
     qint64 totalLength;
     int numPieces;
     int readId;
     bool startVerification;
     bool quit;
     bool wokeUp;

     QList<WriteRequest> writeRequests;
     QList<ReadRequest> readRequests;
     QList<int> pendingVerificationRequests;
     QList<int> newPendingVerificationRequests;
     QList<qint64> fileSizes;

     mutable QMutex mutex;
     mutable QWaitCondition cond;
 };

 #endif