Viadeo Twitter Google Bookmarks ! Facebook Digg del.icio.us MySpace Yahoo MyWeb Blinklist Netvouz Reddit Simpy StumbleUpon Bookmarks Windows Live Favorites 
Logo Documentation Qt ·  Page d'accueil  ·  Toutes les classes  ·  Classes principales  ·  Annotées  ·  Classes groupées  ·  Modules  ·  Fonctions  · 

peerwireclient.cpp Example File
network/torrent/peerwireclient.cpp

 /****************************************************************************
 **
 ** Copyright (C) 2004-2007 Trolltech ASA. All rights reserved.
 **
 ** This file is part of the example classes of the Qt Toolkit.
 **
 ** This file may be used under the terms of the GNU General Public
 ** License version 2.0 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 GNU
 ** General Public Licensing requirements will be met:
 ** http://www.trolltech.com/products/qt/opensource.html
 **
 ** If you are unsure which license is appropriate for your use, please
 ** review the following information:
 ** http://www.trolltech.com/products/qt/licensing.html or contact the
 ** sales department at sales@trolltech.com.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ****************************************************************************/

 #include "peerwireclient.h"

 #include <QHostAddress>
 #include <QTimerEvent>

 static const int PendingRequestTimeout = 60 * 1000;
 static const int ClientTimeout = 120 * 1000;
 static const int ConnectTimeout = 60 * 1000;
 static const int KeepAliveInterval = 30 * 1000;
 static const int RateControlTimerDelay = 2000;
 static const int MinimalHeaderSize = 48;
 static const int FullHeaderSize = 68;
 static const char ProtocolId[] = "BitTorrent protocol";
 static const char ProtocolIdSize = 19;

 // Reads a 32bit unsigned int from data in network order.
 static inline quint32 fromNetworkData(const char *data)
 {
     const unsigned char *udata = (const unsigned char *)data;
     return (quint32(udata[0]) << 24)
         | (quint32(udata[1]) << 16)
         | (quint32(udata[2]) << 8)
         | (quint32(udata[3]));
 }

 // Writes a 32bit unsigned int from num to data in network order.
 static inline void toNetworkData(quint32 num, char *data)
 {
     unsigned char *udata = (unsigned char *)data;
     udata[3] = (num & 0xff);
     udata[2] = (num & 0xff00) >> 8;
     udata[1] = (num & 0xff0000) >> 16;
     udata[0] = (num & 0xff000000) >> 24;
 }

 // Constructs an unconnected PeerWire client and starts the connect timer.
 PeerWireClient::PeerWireClient(const QByteArray &peerId, QObject *parent)
     : QTcpSocket(parent), pendingBlockSizes(0),
       pwState(ChokingPeer | ChokedByPeer), receivedHandShake(false), gotPeerId(false),
       sentHandShake(false), nextPacketLength(-1), pendingRequestTimer(0), invalidateTimeout(false),
       keepAliveTimer(0), torrentPeer(0)
 {
     memset(uploadSpeedData, 0, sizeof(uploadSpeedData));
     memset(downloadSpeedData, 0, sizeof(downloadSpeedData));

     transferSpeedTimer = startTimer(RateControlTimerDelay);
     timeoutTimer = startTimer(ConnectTimeout);
     peerIdString = peerId;

     connect(this, SIGNAL(readyRead()), this, SIGNAL(readyToTransfer()));
     connect(this, SIGNAL(connected()), this, SIGNAL(readyToTransfer()));

     connect(&socket, SIGNAL(connected()),
             this, SIGNAL(connected()));
     connect(&socket, SIGNAL(readyRead()),
             this, SIGNAL(readyRead()));
     connect(&socket, SIGNAL(disconnected()),
             this, SIGNAL(disconnected()));
     connect(&socket, SIGNAL(error(QAbstractSocket::SocketError)),
             this, SIGNAL(error(QAbstractSocket::SocketError)));
     connect(&socket, SIGNAL(bytesWritten(qint64)),
             this, SIGNAL(bytesWritten(qint64)));
     connect(&socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
             this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));

 }

 // Registers the peer ID and SHA1 sum of the torrent, and initiates
 // the handshake.
 void PeerWireClient::initialize(const QByteArray &infoHash, int pieceCount)
 {
     this->infoHash = infoHash;
     peerPieces.resize(pieceCount);
     if (!sentHandShake)
         sendHandShake();
 }

 void PeerWireClient::setPeer(TorrentPeer *peer)
 {
     torrentPeer = peer;
 }

 TorrentPeer *PeerWireClient::peer() const
 {
     return torrentPeer;
 }

 QBitArray PeerWireClient::availablePieces() const
 {
     return peerPieces;
 }

 QList<TorrentBlock> PeerWireClient::incomingBlocks() const
 {
     return incoming;
 }

 // Sends a "choke" message, asking the peer to stop requesting blocks.
 void PeerWireClient::chokePeer()
 {
     const char message[] = {0, 0, 0, 1, 0};
     write(message, sizeof(message));
     pwState |= ChokingPeer;

     // After receiving a choke message, the peer will assume all
     // pending requests are lost.
     pendingBlocks.clear();
     pendingBlockSizes = 0;
 }

 // Sends an "unchoke" message, allowing the peer to start/resume
 // requesting blocks.
 void PeerWireClient::unchokePeer()
 {
     const char message[] = {0, 0, 0, 1, 1};
     write(message, sizeof(message));
     pwState &= ~ChokingPeer;

     if (pendingRequestTimer)
         killTimer(pendingRequestTimer);
 }

 // Sends a "keep-alive" message to prevent the peer from closing
 // the connection when there's no activity
 void PeerWireClient::sendKeepAlive()
 {
     const char message[] = {0, 0, 0, 0};
     write(message, sizeof(message));
 }

 // Sends an "interested" message, informing the peer that it has got
 // pieces that we'd like to download.
 void PeerWireClient::sendInterested()
 {
     const char message[] = {0, 0, 0, 1, 2};
     write(message, sizeof(message));
     pwState |= InterestedInPeer;

     // After telling the peer that we're interested, we expect to get
     // unchoked within a certain timeframe; otherwise we'll drop the
     // connection.
     if (pendingRequestTimer)
         killTimer(pendingRequestTimer);
     pendingRequestTimer = startTimer(PendingRequestTimeout);
 }

 // Sends a "not interested" message, informing the peer that it does
 // not have any pieces that we'd like to download.
 void PeerWireClient::sendNotInterested()
 {
     const char message[] = {0, 0, 0, 1, 3};
     write(message, sizeof(message));
     pwState &= ~InterestedInPeer;
 }

 // Sends a piece notification / a "have" message, informing the peer
 // that we have just downloaded a new piece.
 void PeerWireClient::sendPieceNotification(int piece)
 {
     if (!sentHandShake)
         sendHandShake();

     char message[] = {0, 0, 0, 5, 4, 0, 0, 0, 0};
     toNetworkData(piece, &message[5]);
     write(message, sizeof(message));
 }

 // Sends the complete list of pieces that we have downloaded.
 void PeerWireClient::sendPieceList(const QBitArray &bitField)
 {
     // The bitfield message may only be sent immediately after the
     // handshaking sequence is completed, and before any other
     // messages are sent.
     if (!sentHandShake)
         sendHandShake();

     // Don't send the bitfield if it's all zeros.
     if (bitField.count(true) == 0)
         return;

     int bitFieldSize = bitField.size();
     int size = (bitFieldSize + 7) / 8;
     QByteArray bits(size, '\0');
     for (int i = 0; i < bitFieldSize; ++i) {
         if (bitField.testBit(i)) {
             quint32 byte = quint32(i) / 8;
             quint32 bit = quint32(i) % 8;
             bits[byte] = uchar(bits.at(byte)) | (1 << (7 - bit));
         }
     }

     char message[] = {0, 0, 0, 1, 5};
     toNetworkData(bits.size() + 1, &message[0]);
     write(message, sizeof(message));
     write(bits);
 }

 // Sends a request for a block.
 void PeerWireClient::requestBlock(int piece, int offset, int length)
 {
     char message[] = {0, 0, 0, 1, 6};
     toNetworkData(13, &message[0]);
     write(message, sizeof(message));

     char numbers[4 * 3];
     toNetworkData(piece, &numbers[0]);
     toNetworkData(offset, &numbers[4]);
     toNetworkData(length, &numbers[8]);
     write(numbers, sizeof(numbers));

     incoming << TorrentBlock(piece, offset, length);

     // After requesting a block, we expect the block to be sent by the
     // other peer within a certain number of seconds. Otherwise, we
     // drop the connection.
     if (pendingRequestTimer)
         killTimer(pendingRequestTimer);
     pendingRequestTimer = startTimer(PendingRequestTimeout);
 }

 // Cancels a request for a block.
 void PeerWireClient::cancelRequest(int piece, int offset, int length)
 {
     char message[] = {0, 0, 0, 1, 8};
     toNetworkData(13, &message[0]);
     write(message, sizeof(message));

     char numbers[4 * 3];
     toNetworkData(piece, &numbers[0]);
     toNetworkData(offset, &numbers[4]);
     toNetworkData(length, &numbers[8]);
     write(numbers, sizeof(numbers));

     incoming.removeAll(TorrentBlock(piece, offset, length));
 }

 // Sends a block to the peer.
 void PeerWireClient::sendBlock(int piece, int offset, const QByteArray &data)
 {
     QByteArray block;

     char message[] = {0, 0, 0, 1, 7};
     toNetworkData(9 + data.size(), &message[0]);
     block += QByteArray(message, sizeof(message));

     char numbers[4 * 2];
     toNetworkData(piece, &numbers[0]);
     toNetworkData(offset, &numbers[4]);
     block += QByteArray(numbers, sizeof(numbers));
     block += data;

     BlockInfo blockInfo;
     blockInfo.pieceIndex = piece;
     blockInfo.offset = offset;
     blockInfo.length = data.size();
     blockInfo.block = block;

     pendingBlocks << blockInfo;
     pendingBlockSizes += block.size();

     if (pendingBlockSizes > 32 * 16384) {
         chokePeer();
         unchokePeer();
         return;
     }
     emit readyToTransfer();
 }

 // Attempts to write 'bytes' bytes to the socket from the buffer.
 // This is used by RateController, which precisely controls how much
 // each client can write.
 qint64 PeerWireClient::writeToSocket(qint64 bytes)
 {
     qint64 totalWritten = 0;
     do {
         if (outgoingBuffer.isEmpty() && !pendingBlocks.isEmpty()) {
             BlockInfo block = pendingBlocks.takeFirst();
             pendingBlockSizes -= block.length;
             outgoingBuffer += block.block;
         }
         qint64 written = socket.write(outgoingBuffer.constData(),
                                       qMin<qint64>(bytes - totalWritten, outgoingBuffer.size()));
         if (written <= 0)
             return totalWritten ? totalWritten : written;

         totalWritten += written;
         uploadSpeedData[0] += written;
         outgoingBuffer.remove(0, written);
     } while (totalWritten < bytes && (!outgoingBuffer.isEmpty() || !pendingBlocks.isEmpty()));

     return totalWritten;
 }

 // Attempts to read at most 'bytes' bytes from the socket.
 qint64 PeerWireClient::readFromSocket(qint64 bytes)
 {
     char buffer[1024];
     qint64 totalRead = 0;
     do {
         qint64 bytesRead = socket.read(buffer, qMin<qint64>(sizeof(buffer), bytes - totalRead));
         if (bytesRead <= 0)
             break;
         qint64 oldSize = incomingBuffer.size();
         incomingBuffer.resize(oldSize + bytesRead);
         memcpy(incomingBuffer.data() + oldSize, buffer, bytesRead);

         totalRead += bytesRead;
     } while (totalRead < bytes);

     if (totalRead > 0) {
         downloadSpeedData[0] += totalRead;
         emit bytesReceived(totalRead);
         processIncomingData();
     }
     return totalRead;
 }

 // Returns the average number of bytes per second this client is
 // downloading.
 qint64 PeerWireClient::downloadSpeed() const
 {
     qint64 sum = 0;
     for (unsigned int i = 0; i < sizeof(downloadSpeedData) / sizeof(qint64); ++i)
         sum += downloadSpeedData[i];
     return sum / (8 * 2);
 }

 // Returns the average number of bytes per second this client is
 // uploading.
 qint64 PeerWireClient::uploadSpeed() const
 {
     qint64 sum = 0;
     for (unsigned int i = 0; i < sizeof(uploadSpeedData) / sizeof(qint64); ++i)
         sum += uploadSpeedData[i];
     return sum / (8 * 2);
 }

 void PeerWireClient::setReadBufferSize(int size)
 {
     socket.setReadBufferSize(size);
 }

 bool PeerWireClient::canTransferMore() const
 {
     return bytesAvailable() > 0 || socket.bytesAvailable() > 0
         || !outgoingBuffer.isEmpty() || !pendingBlocks.isEmpty();
 }

 void PeerWireClient::connectToHostImplementation(const QString &hostName,
                                                  quint16 port, OpenMode openMode)

 {
     setOpenMode(openMode);
     socket.connectToHost(hostName, port, openMode);
 }

 void PeerWireClient::diconnectFromHostImplementation()
 {
     socket.disconnectFromHost();
 }

 void PeerWireClient::timerEvent(QTimerEvent *event)
 {
     if (event->timerId() == transferSpeedTimer) {
         // Rotate the upload / download records.
         for (int i = 6; i >= 0; --i) {
             uploadSpeedData[i + 1] = uploadSpeedData[i];
             downloadSpeedData[i + 1] = downloadSpeedData[i];
         }
         uploadSpeedData[0] = 0;
         downloadSpeedData[0] = 0;
     } else if (event->timerId() == timeoutTimer) {
         // Disconnect if we timed out; otherwise the timeout is
         // restarted.
         if (invalidateTimeout) {
             invalidateTimeout = false;
         } else {
             abort();
         }
     } else if (event->timerId() == pendingRequestTimer) {
         abort();
     } else if (event->timerId() == keepAliveTimer) {
         sendKeepAlive();
     }
     QTcpSocket::timerEvent(event);
 }

 // Sends the handshake to the peer.
 void PeerWireClient::sendHandShake()
 {
     sentHandShake = true;

     // Restart the timeout
     if (timeoutTimer)
         killTimer(timeoutTimer);
     timeoutTimer = startTimer(ClientTimeout);

     // Write the 68 byte PeerWire handshake.
     write(&ProtocolIdSize, 1);
     write(ProtocolId, ProtocolIdSize);
     write(QByteArray(8, '\0'));
     write(infoHash);
     write(peerIdString);
 }

 void PeerWireClient::processIncomingData()
 {
     invalidateTimeout = true;
     if (!receivedHandShake) {
         // Check that we received enough data
         if (bytesAvailable() < MinimalHeaderSize)
             return;

         // Sanity check the protocol ID
         QByteArray id = read(ProtocolIdSize + 1);
         if (id.at(0) != ProtocolIdSize || !id.mid(1).startsWith(ProtocolId)) {
             abort();
             return;
         }

         // Discard 8 reserved bytes, then read the info hash and peer ID
         (void) read(8);

         // Read infoHash
         QByteArray peerInfoHash = read(20);
         if (!infoHash.isEmpty() && peerInfoHash != infoHash) {
             abort();
             return;
         }

         emit infoHashReceived(peerInfoHash);
         if (infoHash.isEmpty()) {
             abort();
             return;
         }

         // Send handshake
         if (!sentHandShake)
             sendHandShake();
         receivedHandShake = true;
     }

     // Handle delayed peer id arrival
     if (!gotPeerId) {
         if (bytesAvailable() < 20)
             return;
         gotPeerId = true;
         if (read(20) == peerIdString) {
             // We connected to ourself
             abort();
             return;
         }
     }

     // Initialize keep-alive timer
     if (!keepAliveTimer)
         keepAliveTimer = startTimer(KeepAliveInterval);

     do {
         // Find the packet length
         if (nextPacketLength == -1) {
             if (bytesAvailable() < 4)
                 return;

             char tmp[4];
             read(tmp, sizeof(tmp));
             nextPacketLength = fromNetworkData(tmp);

             if (nextPacketLength < 0 || nextPacketLength > 200000) {
                 // Prevent DoS
                 abort();
                 return;
             }
         }

         // KeepAlive
         if (nextPacketLength == 0) {
             nextPacketLength = -1;
             continue;
         }

         // Wait with parsing until the whole packet has been received
         if (bytesAvailable() < nextPacketLength)
             return;

         // Read the packet
         QByteArray packet = read(nextPacketLength);
         if (packet.size() != nextPacketLength) {
             abort();
             return;
         }

         switch (packet.at(0)) {
         case ChokePacket:
             // We have been choked.
             pwState |= ChokedByPeer;
             incoming.clear();
             if (pendingRequestTimer)
                 killTimer(pendingRequestTimer);
             emit choked();
             break;
         case UnchokePacket:
             // We have been unchoked.
             pwState &= ~ChokedByPeer;
             emit unchoked();
             break;
         case InterestedPacket:
             // The peer is interested in downloading.
             pwState |= PeerIsInterested;
             emit interested();
             break;
         case NotInterestedPacket:
             // The peer is not interested in downloading.
             pwState &= ~PeerIsInterested;
             emit notInterested();
             break;
         case HavePacket: {
             // The peer has a new piece available.
             quint32 index = fromNetworkData(&packet.data()[1]);
             if (index < quint32(peerPieces.size())) {
                 // Only accept indexes within the valid range.
                 peerPieces.setBit(int(index));
             }
             emit piecesAvailable(availablePieces());
             break;
         }
         case BitFieldPacket:
             // The peer has the following pieces available.
             for (int i = 1; i < packet.size(); ++i) {
                 for (int bit = 0; bit < 8; ++bit) {
                     if (packet.at(i) & (1 << (7 - bit))) {
                         int bitIndex = int(((i - 1) * 8) + bit);
                         if (bitIndex >= 0 && bitIndex < peerPieces.size()) {
                             // Occasionally, broken clients claim to have
                             // pieces whose index is outside the valid range.
                             // The most common mistake is the index == size
                             // case.
                             peerPieces.setBit(bitIndex);
                         }
                     }
                 }
             }
             emit piecesAvailable(availablePieces());
             break;
         case RequestPacket: {
             // The peer requests a block.
             quint32 index = fromNetworkData(&packet.data()[1]);
             quint32 begin = fromNetworkData(&packet.data()[5]);
             quint32 length = fromNetworkData(&packet.data()[9]);
             emit blockRequested(int(index), int(begin), int(length));
             break;
         }
         case PiecePacket: {
             int index = int(fromNetworkData(&packet.data()[1]));
             int begin = int(fromNetworkData(&packet.data()[5]));

             incoming.removeAll(TorrentBlock(index, begin, packet.size() - 9));

             // The peer sends a block.
             emit blockReceived(index, begin, packet.mid(9));

             // Kill the pending block timer.
             if (pendingRequestTimer) {
                 killTimer(pendingRequestTimer);
                 pendingRequestTimer = 0;
             }
             break;
         }
         case CancelPacket: {
             // The peer cancels a block request.
             quint32 index = fromNetworkData(&packet.data()[1]);
             quint32 begin = fromNetworkData(&packet.data()[5]);
             quint32 length = fromNetworkData(&packet.data()[9]);
             for (int i = 0; i < pendingBlocks.size(); ++i) {
                 const BlockInfo &blockInfo = pendingBlocks.at(i);
                 if (blockInfo.pieceIndex == int(index)
                     && blockInfo.offset == int(begin)
                     && blockInfo.length == int(length)) {
                     pendingBlocks.removeAt(i);
                     break;
                 }
             }
             break;
         }
         default:
             // Unsupported packet type; just ignore it.
             break;
         }
         nextPacketLength = -1;
     } while (bytesAvailable() > 0);
 }

 void PeerWireClient::socketStateChanged(QAbstractSocket::SocketState state)
 {
     setLocalAddress(socket.localAddress());
     setLocalPort(socket.localPort());
     setPeerName(socket.peerName());
     setPeerAddress(socket.peerAddress());
     setPeerPort(socket.peerPort());
     setSocketState(state);
 }

 qint64 PeerWireClient::readData(char *data, qint64 size)
 {
     int n = qMin<int>(size, incomingBuffer.size());
     memcpy(data, incomingBuffer.constData(), n);
     incomingBuffer.remove(0, n);
     return n;
 }

 qint64 PeerWireClient::readLineData(char *data, qint64 maxlen)
 {
     return QIODevice::readLineData(data, maxlen);
 }

 qint64 PeerWireClient::writeData(const char *data, qint64 size)
 {
     int oldSize = outgoingBuffer.size();
     outgoingBuffer.resize(oldSize + size);
     memcpy(outgoingBuffer.data() + oldSize, data, size);
     emit readyToTransfer();
     return size;
 }

Publicité

Best Of

Actualités les plus lues

Semaine
Mois
Année
  1. « Quelque chose ne va vraiment pas avec les développeurs "modernes" », un développeur à "l'ancienne" critique la multiplication des bibliothèques 102
  2. Pourquoi les programmeurs sont-ils moins payés que les gestionnaires de programmes ? Manquent-ils de pouvoir de négociation ? 53
  3. «Le projet de loi des droits du développeur» : quelles conditions doivent remplir les entreprises pour que le développeur puisse réussir ? 73
  4. Les développeurs détestent-ils les antivirus ? Un programmeur manifeste sa haine envers ces solutions de sécurité 28
  5. Qt Commercial : Digia organise un webinar gratuit le 27 mars sur la conception d'interfaces utilisateur et d'applications avec le framework 0
  6. Quelles nouveautés de C++11 Visual C++ doit-il rapidement intégrer ? Donnez-nous votre avis 10
  7. 2017 : un quinquennat pour une nouvelle version du C++ ? Possible, selon Herb Sutter 11
Page suivante
  1. Linus Torvalds : le "C++ est un langage horrible", en justifiant le choix du C pour le système de gestion de version Git 100
  2. Comment prendre en compte l'utilisateur dans vos applications ? Pour un développeur, « 90 % des utilisateurs sont des idiots » 229
  3. Quel est LE livre que tout développeur doit lire absolument ? Celui qui vous a le plus marqué et inspiré 96
  4. Apple cède et s'engage à payer des droits à Nokia, le conflit des brevets entre les deux firmes s'achève 158
  5. Nokia porte à nouveau plainte contre Apple pour violation de sept nouveaux brevets 158
  6. Quel est le code dont vous êtes le plus fier ? Pourquoi l'avez-vous écrit ? Et pourquoi vous a-t-il donné autant de satisfaction ? 83
  7. « Quelque chose ne va vraiment pas avec les développeurs "modernes" », un développeur à "l'ancienne" critique la multiplication des bibliothèques 101
Page suivante

Le blog Digia au hasard

Logo

Créer des applications avec un style Metro avec Qt, exemples en QML et C++, un article de Digia Qt traduit par Thibaut Cuvelier

Le blog Digia est l'endroit privilégié pour la communication sur l'édition commerciale de Qt, où des réponses publiques sont apportées aux questions les plus posées au support. Lire l'article.

Communauté

Ressources

Liens utiles

Contact

  • Vous souhaitez rejoindre la rédaction ou proposer un tutoriel, une traduction, une question... ? Postez dans le forum Contribuez ou contactez-nous par MP ou par email (voir en bas de page).

Qt dans le magazine

Cette page est une traduction d'une page de la documentation de Qt, écrite par Nokia Corporation and/or its subsidiary(-ies). Les éventuels problèmes résultant d'une mauvaise traduction ne sont pas imputables à Nokia. Qt 4.2
Copyright © 2012 Developpez LLC. Tous droits réservés Developpez LLC. Aucune reproduction, même partielle, ne peut être faite de ce site et de l'ensemble de son contenu : textes, documents et images sans l'autorisation expresse de Developpez LLC. Sinon, vous encourez selon la loi jusqu'à 3 ans de prison et jusqu'à 300 000 E de dommages et intérêts. Cette page est déposée à la SACD.
Vous avez déniché une erreur ? Un bug ? Une redirection cassée ? Ou tout autre problème, quel qu'il soit ? Ou bien vous désirez participer à ce projet de traduction ? N'hésitez pas à nous contacter ou par MP !
 
 
 
 
Partenaires

Hébergement Web