torrentclient.h Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #ifndef TORRENTCLIENT_H
  #define TORRENTCLIENT_H

  #include <QBitArray>
  #include <QHostAddress>
  #include <QList>

  class MetaInfo;
  class PeerWireClient;
  class TorrentClientPrivate;
  class TorrentPeer;
  class TorrentPiece;
  class QTimerEvent;

  class TorrentPeer {
  public:
      QHostAddress address;
      quint16 port;
      QString id;
      bool interesting;
      bool seed;
      uint lastVisited;
      uint connectStart;
      uint connectTime;
      QBitArray pieces;
      int numCompletedPieces;

      inline bool operator==(const TorrentPeer &other)
      {
          return port == other.port
              && address == other.address
              && id == other.id;
      }
  };

  class TorrentClient : public QObject
  {
      Q_OBJECT

  public:
      enum State {
          Idle,
          Paused,
          Stopping,
          Preparing,
          Searching,
          Connecting,
          WarmingUp,
          Downloading,
          Endgame,
          Seeding
      };
      enum Error {
          UnknownError,
          TorrentParseError,
          InvalidTrackerError,
          FileError,
          ServerError
      };

      TorrentClient(QObject *parent = 0);
      ~TorrentClient();

      bool setTorrent(const QString &fileName);
      bool setTorrent(const QByteArray &torrentData);
      MetaInfo metaInfo() const;

      void setMaxConnections(int connections);
      int maxConnections() const;

      void setDestinationFolder(const QString &directory);
      QString destinationFolder() const;

      void setDumpedState(const QByteArray &dumpedState);
      QByteArray dumpedState() const;

      // Progress and stats for download feedback.
      qint64 progress() const;
      void setDownloadedBytes(qint64 bytes);
      qint64 downloadedBytes() const;
      void setUploadedBytes(qint64 bytes);
      qint64 uploadedBytes() const;
      int connectedPeerCount() const;
      int seedCount() const;

      // Accessors for the tracker
      QByteArray peerId() const;
      QByteArray infoHash() const;
      quint16 serverPort() const;

      // State and error.
      State state() const;
      QString stateString() const;
      Error error() const;
      QString errorString() const;

  signals:
      void stateChanged(TorrentClient::State state);
      void error(TorrentClient::Error error);

      void downloadCompleted();
      void peerInfoUpdated();

      void dataSent(int uploadedBytes);
      void dataReceived(int downloadedBytes);
      void progressUpdated(int percentProgress);
      void downloadRateUpdated(int bytesPerSecond);
      void uploadRateUpdated(int bytesPerSecond);

      void stopped();

  public slots:
      void start();
      void stop();
      void setPaused(bool paused);
      void setupIncomingConnection(PeerWireClient *client);

  protected slots:
      void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;

  private slots:
      // File management
      void sendToPeer(int readId, int pieceIndex, int begin, const QByteArray &data);
      void fullVerificationDone();
      void pieceVerified(int pieceIndex, bool ok);
      void handleFileError();

      // Connection handling
      void connectToPeers();
      QList<TorrentPeer *> weighedFreePeers() const;
      void setupOutgoingConnection();
      void initializeConnection(PeerWireClient *client);
      void removeClient();
      void peerPiecesAvailable(const QBitArray &pieces);
      void peerRequestsBlock(int pieceIndex, int begin, int length);
      void blockReceived(int pieceIndex, int begin, const QByteArray &data);
      void peerWireBytesWritten(qint64 bytes);
      void peerWireBytesReceived(qint64 bytes);
      int blocksLeftForPiece(const TorrentPiece *piece) const;

      // Scheduling
      void scheduleUploads();
      void scheduleDownloads();
      void schedulePieceForClient(PeerWireClient *client);
      void requestMore(PeerWireClient *client);
      int requestBlocks(PeerWireClient *client, TorrentPiece *piece, int maxBlocks);
      void peerChoked();
      void peerUnchoked();

      // Tracker handling
      void addToPeerList(const QList<TorrentPeer> &peerList);
      void trackerStopped();

      // Progress
      void updateProgress(int progress = -1);

  private:
      TorrentClientPrivate *d;
      friend class TorrentClientPrivate;
  };

  #endif