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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 1528 insertions, 0 deletions

diff --git a/examples/network/torrent/torrentclient.cpp b/examples/network/torrent/torrentclient.cpp
new file mode 100644
index 0000000000..3df1bb886f
--- /dev/null
+++ b/examples/network/torrent/torrentclient.cpp
@@ -0,0 +1,1528 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 Nokia Corporation and its Subsidiary(-ies) 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."
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "connectionmanager.h"
+#include "filemanager.h"
+#include "metainfo.h"
+#include "torrentclient.h"
+#include "torrentserver.h"
+#include "trackerclient.h"
+#include "peerwireclient.h"
+#include "ratecontroller.h"
+
+#include <QtCore>
+#include <QNetworkInterface>
+
+// These constants could also be configurable by the user.
+static const int ServerMinPort = 6881;
+static const int ServerMaxPort = /* 6889 */ 7000;
+static const int BlockSize = 16384;
+static const int MaxBlocksInProgress = 5;
+static const int MaxBlocksInMultiMode = 2;
+static const int MaxConnectionPerPeer = 1;
+static const int RateControlWindowLength = 10;
+static const int RateControlTimerDelay = 1000;
+static const int MinimumTimeBeforeRevisit = 30;
+static const int MaxUploads = 4;
+static const int UploadScheduleInterval = 10000;
+static const int EndGamePieces = 5;
+
+class TorrentPiece {
+public:
+    int index;
+    int length;
+    QBitArray completedBlocks;
+    QBitArray requestedBlocks;
+    bool inProgress;
+};
+
+class TorrentClientPrivate
+{
+public:
+    TorrentClientPrivate(TorrentClient *qq);
+
+    // State / error
+    void setError(TorrentClient::Error error);
+    void setState(TorrentClient::State state);
+    TorrentClient::Error error;
+    TorrentClient::State state;
+    QString errorString;
+    QString stateString;
+
+    // Where to save data
+    QString destinationFolder;
+    MetaInfo metaInfo;
+
+    // Announce tracker and file manager
+    QByteArray peerId;
+    QByteArray infoHash;
+    TrackerClient trackerClient;
+    FileManager fileManager;
+
+    // Connections
+    QList<PeerWireClient *> connections;
+    QList<TorrentPeer *> peers;
+    bool schedulerCalled;
+    void callScheduler();
+    bool connectingToClients;
+    void callPeerConnector();
+    int uploadScheduleTimer;
+
+    // Pieces
+    QMap<int, PeerWireClient *> readIds;
+    QMultiMap<PeerWireClient *, TorrentPiece *> payloads;
+    QMap<int, TorrentPiece *> pendingPieces;
+    QBitArray completedPieces;
+    QBitArray incompletePieces;
+    int pieceCount;
+
+    // Progress
+    int lastProgressValue;
+    qint64 downloadedBytes;
+    qint64 uploadedBytes;
+    int downloadRate[RateControlWindowLength];
+    int uploadRate[RateControlWindowLength];
+    int transferRateTimer;
+
+    TorrentClient *q;
+};
+
+TorrentClientPrivate::TorrentClientPrivate(TorrentClient *qq)
+    : trackerClient(qq), q(qq)
+{
+    error = TorrentClient::UnknownError;
+    state = TorrentClient::Idle;
+    errorString = QT_TRANSLATE_NOOP(TorrentClient, "Unknown error");
+    stateString = QT_TRANSLATE_NOOP(TorrentClient, "Idle");
+    schedulerCalled = false;
+    connectingToClients = false;
+    uploadScheduleTimer = 0;
+    lastProgressValue = -1;
+    pieceCount = 0;
+    downloadedBytes = 0;
+    uploadedBytes = 0;
+    memset(downloadRate, 0, sizeof(downloadRate));
+    memset(uploadRate, 0, sizeof(uploadRate));
+    transferRateTimer = 0;
+}
+
+void TorrentClientPrivate::setError(TorrentClient::Error errorCode)
+{
+    this->error = errorCode;
+    switch (error) {
+    case TorrentClient::UnknownError:
+        errorString = QT_TRANSLATE_NOOP(TorrentClient, "Unknown error");
+        break;
+    case TorrentClient::TorrentParseError:
+        errorString = QT_TRANSLATE_NOOP(TorrentClient, "Invalid torrent data");
+        break;
+    case TorrentClient::InvalidTrackerError:
+        errorString = QT_TRANSLATE_NOOP(TorrentClient, "Unable to connect to tracker");
+        break;
+    case TorrentClient::FileError:
+        errorString = QT_TRANSLATE_NOOP(TorrentClient, "File error");
+        break;
+    case TorrentClient::ServerError:
+        errorString = QT_TRANSLATE_NOOP(TorrentClient, "Unable to initialize server");
+        break;
+    }
+    emit q->error(errorCode);
+}
+
+void TorrentClientPrivate::setState(TorrentClient::State state)
+{
+    this->state = state;
+    switch (state) {
+    case TorrentClient::Idle:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Idle");
+        break;
+    case TorrentClient::Paused:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Paused");
+        break;
+    case TorrentClient::Stopping:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Stopping");
+        break;
+    case TorrentClient::Preparing:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Preparing");
+        break;
+    case TorrentClient::Searching:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Searching");
+        break;
+    case TorrentClient::Connecting:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Connecting");
+        break;
+    case TorrentClient::WarmingUp:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Warming up");
+        break;
+    case TorrentClient::Downloading:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Downloading");
+        break;
+    case TorrentClient::Endgame:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Finishing");
+        break;
+    case TorrentClient::Seeding:
+        stateString = QT_TRANSLATE_NOOP(TorrentClient, "Seeding");
+        break;
+    }
+    emit q->stateChanged(state);
+}
+
+void TorrentClientPrivate::callScheduler()
+{
+    if (!schedulerCalled) {
+        schedulerCalled = true;
+        QMetaObject::invokeMethod(q, "scheduleDownloads", Qt::QueuedConnection);
+    }
+}
+
+void TorrentClientPrivate::callPeerConnector()
+{
+    if (!connectingToClients) {
+        connectingToClients = true;
+        QTimer::singleShot(10000, q, SLOT(connectToPeers()));
+    }
+}
+
+TorrentClient::TorrentClient(QObject *parent)
+    : QObject(parent), d(new TorrentClientPrivate(this))
+{
+    // Connect the file manager
+    connect(&d->fileManager, SIGNAL(dataRead(int,int,int,QByteArray)),
+            this, SLOT(sendToPeer(int,int,int,QByteArray)));
+    connect(&d->fileManager, SIGNAL(verificationProgress(int)),
+            this, SLOT(updateProgress(int)));
+    connect(&d->fileManager, SIGNAL(verificationDone()),
+            this, SLOT(fullVerificationDone()));
+    connect(&d->fileManager, SIGNAL(pieceVerified(int,bool)),
+            this, SLOT(pieceVerified(int,bool)));
+    connect(&d->fileManager, SIGNAL(error()),
+            this, SLOT(handleFileError()));
+
+    // Connect the tracker client
+    connect(&d->trackerClient, SIGNAL(peerListUpdated(QList<TorrentPeer>)),
+            this, SLOT(addToPeerList(QList<TorrentPeer>)));
+    connect(&d->trackerClient, SIGNAL(stopped()),
+            this, SIGNAL(stopped()));
+}
+
+TorrentClient::~TorrentClient()
+{
+    qDeleteAll(d->peers);
+    qDeleteAll(d->pendingPieces);
+    delete d;
+}
+
+bool TorrentClient::setTorrent(const QString &fileName)
+{
+    QFile file(fileName);
+    if (!file.open(QIODevice::ReadOnly) || !setTorrent(file.readAll())) {
+        d->setError(TorrentParseError);
+        return false;
+    }
+    return true;
+}
+
+bool TorrentClient::setTorrent(const QByteArray &torrentData)
+{
+    if (!d->metaInfo.parse(torrentData)) {
+        d->setError(TorrentParseError);
+        return false;
+    }
+
+    // Calculate SHA1 hash of the "info" section in the torrent
+    QByteArray infoValue = d->metaInfo.infoValue();
+    d->infoHash = QCryptographicHash::hash(infoValue, QCryptographicHash::Sha1);
+
+    return true;
+}
+
+MetaInfo TorrentClient::metaInfo() const
+{
+    return d->metaInfo;
+}
+
+void TorrentClient::setDestinationFolder(const QString &directory)
+{
+    d->destinationFolder = directory;
+}
+
+QString TorrentClient::destinationFolder() const
+{
+    return d->destinationFolder;
+}
+
+void TorrentClient::setDumpedState(const QByteArray &dumpedState)
+{
+    // Recover partially completed pieces
+    QDataStream stream(dumpedState);
+
+    quint16 version = 0;
+    stream >> version;
+    if (version != 2)
+        return;
+
+    stream >> d->completedPieces;
+
+    while (!stream.atEnd()) {
+        int index;
+        int length;
+        QBitArray completed;
+        stream >> index >> length >> completed;
+        if (stream.status() != QDataStream::Ok) {
+            d->completedPieces.clear();
+            break;
+        }
+
+        TorrentPiece *piece = new TorrentPiece;
+        piece->index = index;
+        piece->length = length;
+        piece->completedBlocks = completed;
+        piece->requestedBlocks.resize(completed.size());
+        piece->inProgress = false;
+        d->pendingPieces[index] = piece;
+    }
+}
+
+QByteArray TorrentClient::dumpedState() const
+{
+    QByteArray partials;
+    QDataStream stream(&partials, QIODevice::WriteOnly);
+
+    stream << quint16(2);
+    stream << d->completedPieces;
+
+    // Save the state of all partially downloaded pieces into a format
+    // suitable for storing in settings.
+    QMap<int, TorrentPiece *>::ConstIterator it = d->pendingPieces.constBegin();
+    while (it != d->pendingPieces.constEnd()) {
+        TorrentPiece *piece = it.value();
+        if (blocksLeftForPiece(piece) > 0 && blocksLeftForPiece(piece) < piece->completedBlocks.size()) {
+            stream << piece->index;
+            stream << piece->length;
+            stream << piece->completedBlocks;
+        }
+        ++it;
+    }
+
+    return partials;
+}
+
+qint64 TorrentClient::progress() const
+{
+    return d->lastProgressValue;
+}
+
+void TorrentClient::setDownloadedBytes(qint64 bytes)
+{
+    d->downloadedBytes = bytes;
+}
+
+qint64 TorrentClient::downloadedBytes() const
+{
+    return d->downloadedBytes;
+}
+
+void TorrentClient::setUploadedBytes(qint64 bytes)
+{
+    d->uploadedBytes = bytes;
+}
+
+qint64 TorrentClient::uploadedBytes() const
+{
+    return d->uploadedBytes;
+}
+
+int TorrentClient::connectedPeerCount() const
+{
+    int tmp = 0;
+    foreach (PeerWireClient *client, d->connections) {
+        if (client->state() == QAbstractSocket::ConnectedState)
+            ++tmp;
+    }
+    return tmp;
+}
+
+int TorrentClient::seedCount() const
+{
+    int tmp = 0;
+    foreach (PeerWireClient *client, d->connections) {
+        if (client->availablePieces().count(true) == d->pieceCount)
+            ++tmp;
+    }
+    return tmp;
+}
+
+TorrentClient::State TorrentClient::state() const
+{
+    return d->state;
+}
+
+QString TorrentClient::stateString() const
+{
+    return d->stateString;
+}
+
+TorrentClient::Error TorrentClient::error() const
+{
+    return d->error;
+}
+
+QString TorrentClient::errorString() const
+{
+    return d->errorString;
+}
+
+QByteArray TorrentClient::peerId() const
+{
+    return d->peerId;
+}
+
+QByteArray TorrentClient::infoHash() const
+{
+    return d->infoHash;
+}
+
+void TorrentClient::start()
+{
+    if (d->state != Idle)
+        return;
+
+    TorrentServer::instance()->addClient(this);
+
+    // Initialize the file manager
+    d->setState(Preparing);
+    d->fileManager.setMetaInfo(d->metaInfo);
+    d->fileManager.setDestinationFolder(d->destinationFolder);
+    d->fileManager.setCompletedPieces(d->completedPieces);
+    d->fileManager.start(QThread::LowestPriority);
+    d->fileManager.startDataVerification();
+}
+
+void TorrentClient::stop()
+{
+    if (d->state == Stopping)
+        return;
+
+    TorrentServer::instance()->removeClient(this);
+
+    // Update the state
+    State oldState = d->state;
+    d->setState(Stopping);
+
+    // Stop the timer
+    if (d->transferRateTimer) {
+        killTimer(d->transferRateTimer);
+        d->transferRateTimer = 0;
+    }
+
+    // Abort all existing connections
+    foreach (PeerWireClient *client, d->connections) {
+        RateController::instance()->removeSocket(client);
+        ConnectionManager::instance()->removeConnection(client);
+        client->abort();
+    }
+    d->connections.clear();
+
+    // Perhaps stop the tracker
+    if (oldState > Preparing) {
+        d->trackerClient.stop();
+    } else {
+        d->setState(Idle);
+        emit stopped();
+    }
+}
+
+void TorrentClient::setPaused(bool paused)
+{
+    if (paused) {
+        // Abort all connections, and set the max number of
+        // connections to 0. Keep the list of peers, so we can quickly
+        // resume later.
+        d->setState(Paused);
+        foreach (PeerWireClient *client, d->connections)
+            client->abort();
+        d->connections.clear();
+        TorrentServer::instance()->removeClient(this);
+    } else {
+        // Restore the max number of connections, and start the peer
+        // connector. We should also quickly start receiving incoming
+        // connections.
+        d->setState(d->completedPieces.count(true) == d->fileManager.pieceCount()
+                    ? Seeding : Searching);
+        connectToPeers();
+        TorrentServer::instance()->addClient(this);
+    }
+}
+
+void TorrentClient::timerEvent(QTimerEvent *event)
+{
+    if (event->timerId() == d->uploadScheduleTimer) {
+        // Update the state of who's choked and who's not
+        scheduleUploads();
+        return;
+    }
+
+    if (event->timerId() != d->transferRateTimer) {
+        QObject::timerEvent(event);
+        return;
+    }
+
+    // Calculate average upload/download rate
+    qint64 uploadBytesPerSecond = 0;
+    qint64 downloadBytesPerSecond = 0;
+    for (int i = 0; i < RateControlWindowLength; ++i) {
+        uploadBytesPerSecond += d->uploadRate[i];
+        downloadBytesPerSecond += d->downloadRate[i];
+    }
+    uploadBytesPerSecond /= qint64(RateControlWindowLength);
+    downloadBytesPerSecond /= qint64(RateControlWindowLength);
+    for (int i = RateControlWindowLength - 2; i >= 0; --i) {
+        d->uploadRate[i + 1] = d->uploadRate[i];
+        d->downloadRate[i + 1] = d->downloadRate[i];
+    }
+    d->uploadRate[0] = 0;
+    d->downloadRate[0] = 0;
+    emit uploadRateUpdated(int(uploadBytesPerSecond));
+    emit downloadRateUpdated(int(downloadBytesPerSecond));
+
+    // Stop the timer if there is no activity.
+    if (downloadBytesPerSecond == 0 && uploadBytesPerSecond == 0) {
+        killTimer(d->transferRateTimer);
+        d->transferRateTimer = 0;
+    }
+}
+
+void TorrentClient::sendToPeer(int readId, int pieceIndex, int begin, const QByteArray &data)
+{
+    // Send the requested block to the peer if the client connection
+    // still exists; otherwise do nothing. This slot is called by the
+    // file manager after it has read a block of data.
+    PeerWireClient *client = d->readIds.value(readId);
+    if (client) {
+        if ((client->peerWireState() & PeerWireClient::ChokingPeer) == 0)
+            client->sendBlock(pieceIndex, begin, data);
+    }
+    d->readIds.remove(readId);
+}
+
+void TorrentClient::fullVerificationDone()
+{
+    // Update our list of completed and incomplete pieces.
+    d->completedPieces = d->fileManager.completedPieces();
+    d->incompletePieces.resize(d->completedPieces.size());
+    d->pieceCount = d->completedPieces.size();
+    for (int i = 0; i < d->fileManager.pieceCount(); ++i) {
+        if (!d->completedPieces.testBit(i))
+            d->incompletePieces.setBit(i);
+    }
+
+    updateProgress();
+
+    // If the checksums show that what the dumped state thought was
+    // partial was in fact complete, then we trust the checksums.
+    QMap<int, TorrentPiece *>::Iterator it = d->pendingPieces.begin();
+    while (it != d->pendingPieces.end()) {
+        if (d->completedPieces.testBit(it.key()))
+            it = d->pendingPieces.erase(it);
+        else
+            ++it;
+    }
+
+    d->uploadScheduleTimer = startTimer(UploadScheduleInterval);
+
+    // Start the server
+    TorrentServer *server = TorrentServer::instance();
+    if (!server->isListening()) {
+        // Set up the peer wire server
+        for (int i = ServerMinPort; i <= ServerMaxPort; ++i) {
+            if (server->listen(QHostAddress::Any, i))
+                break;
+        }
+        if (!server->isListening()) {
+            d->setError(ServerError);
+            return;
+        }
+    }
+
+    d->setState(d->completedPieces.count(true) == d->pieceCount ? Seeding : Searching);
+
+    // Start the tracker client
+    d->trackerClient.start(d->metaInfo);
+}
+
+void TorrentClient::pieceVerified(int pieceIndex, bool ok)
+{
+    TorrentPiece *piece = d->pendingPieces.value(pieceIndex);
+
+    // Remove this piece from all payloads
+    QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.begin();
+    while (it != d->payloads.end()) {
+        if (it.value()->index == pieceIndex)
+            it = d->payloads.erase(it);
+        else
+            ++it;
+    }
+
+    if (!ok) {
+        // If a piece did not pass the SHA1 check, we'll simply clear
+        // its state, and the scheduler will re-request it
+        piece->inProgress = false;
+        piece->completedBlocks.fill(false);
+        piece->requestedBlocks.fill(false);
+        d->callScheduler();
+        return;
+    }
+
+    // Update the peer list so we know who's still interesting.
+    foreach (TorrentPeer *peer, d->peers) {
+        if (!peer->interesting)
+            continue;
+        bool interesting = false;
+        for (int i = 0; i < d->pieceCount; ++i) {
+            if (peer->pieces.testBit(i) && d->incompletePieces.testBit(i)) {
+                interesting = true;
+                break;
+            }
+        }
+        peer->interesting = interesting;
+    }
+
+    // Delete the piece and update our structures.
+    delete piece;
+    d->pendingPieces.remove(pieceIndex);
+    d->completedPieces.setBit(pieceIndex);
+    d->incompletePieces.clearBit(pieceIndex);
+
+    // Notify connected peers.
+    foreach (PeerWireClient *client, d->connections) {
+        if (client->state() == QAbstractSocket::ConnectedState
+            && !client->availablePieces().testBit(pieceIndex)) {
+            client->sendPieceNotification(pieceIndex);
+        }
+    }
+
+    // Notify the tracker if we've entered Seeding status; otherwise
+    // call the scheduler.
+    int completed = d->completedPieces.count(true);
+    if (completed == d->pieceCount) {
+        if (d->state != Seeding) {
+            d->setState(Seeding);
+            d->trackerClient.startSeeding();
+        }
+    } else {
+        if (completed == 1)
+            d->setState(Downloading);
+        else if (d->incompletePieces.count(true) < 5 && d->pendingPieces.size() > d->incompletePieces.count(true))
+            d->setState(Endgame);
+        d->callScheduler();
+    }
+
+    updateProgress();
+}
+
+void TorrentClient::handleFileError()
+{
+    if (d->state == Paused)
+        return;
+    setPaused(true);
+    emit error(FileError);
+}
+
+void TorrentClient::connectToPeers()
+{
+    d->connectingToClients = false;
+
+    if (d->state == Stopping || d->state == Idle || d->state == Paused)
+        return;
+
+    if (d->state == Searching)
+        d->setState(Connecting);
+
+    // Find the list of peers we are not currently connected to, where
+    // the more interesting peers are listed more than once.
+    QList<TorrentPeer *> weighedPeers = weighedFreePeers();
+
+    // Start as many connections as we can
+    while (!weighedPeers.isEmpty() && ConnectionManager::instance()->canAddConnection()
+           && (qrand() % (ConnectionManager::instance()->maxConnections() / 2))) {
+        PeerWireClient *client = new PeerWireClient(ConnectionManager::instance()->clientId(), this);
+        RateController::instance()->addSocket(client);
+        ConnectionManager::instance()->addConnection(client);
+
+        initializeConnection(client);
+        d->connections << client;
+
+        // Pick a random peer from the list of weighed peers.
+        TorrentPeer *peer = weighedPeers.takeAt(qrand() % weighedPeers.size());
+        weighedPeers.removeAll(peer);
+        peer->connectStart = QDateTime::currentDateTime().toTime_t();
+        peer->lastVisited = peer->connectStart;
+
+        // Connect to the peer.
+        client->setPeer(peer);
+        client->connectToHost(peer->address, peer->port);
+    }
+}
+
+QList<TorrentPeer *> TorrentClient::weighedFreePeers() const
+{
+    QList<TorrentPeer *> weighedPeers;
+
+    // Generate a list of peers that we want to connect to.
+    uint now = QDateTime::currentDateTime().toTime_t();
+    QList<TorrentPeer *> freePeers;
+    QMap<QString, int> connectionsPerPeer;
+    foreach (TorrentPeer *peer, d->peers) {
+        bool busy = false;
+        foreach (PeerWireClient *client, d->connections) {
+            if (client->state() == PeerWireClient::ConnectedState
+                && client->peerAddress() == peer->address
+                && client->peerPort() == peer->port) {
+                if (++connectionsPerPeer[peer->address.toString()] >= MaxConnectionPerPeer) {
+                    busy = true;
+                    break;
+                }
+            }
+        }
+        if (!busy && (now - peer->lastVisited) > uint(MinimumTimeBeforeRevisit))
+            freePeers << peer;
+    }
+
+    // Nothing to connect to
+    if (freePeers.isEmpty())
+        return weighedPeers;
+
+    // Assign points based on connection speed and pieces available.
+    QList<QPair<int, TorrentPeer *> > points;
+    foreach (TorrentPeer *peer, freePeers) {
+        int tmp = 0;
+        if (peer->interesting) {
+            tmp += peer->numCompletedPieces;
+            if (d->state == Seeding)
+                tmp = d->pieceCount - tmp;
+            if (!peer->connectStart) // An unknown peer is as interesting as a seed
+                tmp += d->pieceCount;
+
+            // 1/5 of the total score for each second below 5 it takes to
+            // connect.
+            if (peer->connectTime < 5)
+                tmp += (d->pieceCount / 10) * (5 - peer->connectTime);
+        }
+        points << QPair<int, TorrentPeer *>(tmp, peer);
+    }
+    qSort(points);
+
+    // Minimize the list so the point difference is never more than 1.
+    typedef QPair<int,TorrentPeer*> PointPair;
+    QMultiMap<int, TorrentPeer *> pointMap;
+    int lowestScore = 0;
+    int lastIndex = 0;
+    foreach (PointPair point, points) {
+        if (point.first > lowestScore) {
+            lowestScore = point.first;
+            ++lastIndex;
+        }
+        pointMap.insert(lastIndex, point.second);
+    }
+
+    // Now make up a list of peers where the ones with more points are
+    // listed many times.
+    QMultiMap<int, TorrentPeer *>::ConstIterator it = pointMap.constBegin();
+    while (it != pointMap.constEnd()) {
+        for (int i = 0; i < it.key() + 1; ++i)
+            weighedPeers << it.value();
+        ++it;
+    }
+
+    return weighedPeers;
+}
+
+void TorrentClient::setupIncomingConnection(PeerWireClient *client)
+{
+    // Connect signals
+    initializeConnection(client);
+
+    // Initialize this client
+    RateController::instance()->addSocket(client);
+    d->connections << client;
+
+    client->initialize(d->infoHash, d->pieceCount);
+    client->sendPieceList(d->completedPieces);
+
+    emit peerInfoUpdated();
+
+    if (d->state == Searching || d->state == Connecting) {
+        int completed = d->completedPieces.count(true);
+        if (completed == 0)
+            d->setState(WarmingUp);
+        else if (d->incompletePieces.count(true) < 5 && d->pendingPieces.size() > d->incompletePieces.count(true))
+            d->setState(Endgame);
+    }
+
+    if (d->connections.isEmpty())
+        scheduleUploads();
+}
+
+void TorrentClient::setupOutgoingConnection()
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+
+    // Update connection statistics.
+    foreach (TorrentPeer *peer, d->peers) {
+        if (peer->port == client->peerPort() && peer->address == client->peerAddress()) {
+            peer->connectTime = peer->lastVisited - peer->connectStart;
+            break;
+        }
+    }
+
+    // Send handshake and piece list
+    client->initialize(d->infoHash, d->pieceCount);
+    client->sendPieceList(d->completedPieces);
+
+    emit peerInfoUpdated();
+
+    if (d->state == Searching || d->state == Connecting) {
+        int completed = d->completedPieces.count(true);
+        if (completed == 0)
+            d->setState(WarmingUp);
+        else if (d->incompletePieces.count(true) < 5 && d->pendingPieces.size() > d->incompletePieces.count(true))
+            d->setState(Endgame);
+    }
+}
+
+void TorrentClient::initializeConnection(PeerWireClient *client)
+{
+    connect(client, SIGNAL(connected()),
+            this, SLOT(setupOutgoingConnection()));
+    connect(client, SIGNAL(disconnected()),
+            this, SLOT(removeClient()));
+    connect(client, SIGNAL(error(QAbstractSocket::SocketError)),
+            this, SLOT(removeClient()));
+    connect(client, SIGNAL(piecesAvailable(QBitArray)),
+            this, SLOT(peerPiecesAvailable(QBitArray)));
+    connect(client, SIGNAL(blockRequested(int,int,int)),
+            this, SLOT(peerRequestsBlock(int,int,int)));
+    connect(client, SIGNAL(blockReceived(int,int,QByteArray)),
+            this, SLOT(blockReceived(int,int,QByteArray)));
+    connect(client, SIGNAL(choked()),
+            this, SLOT(peerChoked()));
+    connect(client, SIGNAL(unchoked()),
+            this, SLOT(peerUnchoked()));
+    connect(client, SIGNAL(bytesWritten(qint64)),
+            this, SLOT(peerWireBytesWritten(qint64)));
+    connect(client, SIGNAL(bytesReceived(qint64)),
+            this, SLOT(peerWireBytesReceived(qint64)));
+}
+
+void TorrentClient::removeClient()
+{
+    PeerWireClient *client = static_cast<PeerWireClient *>(sender());
+
+    // Remove the host from our list of known peers if the connection
+    // failed.
+    if (client->peer() && client->error() == QAbstractSocket::ConnectionRefusedError)
+        d->peers.removeAll(client->peer());
+
+    // Remove the client from RateController and all structures.
+    RateController::instance()->removeSocket(client);
+    d->connections.removeAll(client);
+    QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.find(client);
+    while (it != d->payloads.end() && it.key() == client) {
+        TorrentPiece *piece = it.value();
+        piece->inProgress = false;
+        piece->requestedBlocks.fill(false);
+        it = d->payloads.erase(it);
+    }
+
+    // Remove pending read requests.
+    QMapIterator<int, PeerWireClient *> it2(d->readIds);
+    while (it2.findNext(client))
+        d->readIds.remove(it2.key());
+
+    // Delete the client later.
+    disconnect(client, SIGNAL(disconnected()), this, SLOT(removeClient()));
+    client->deleteLater();
+    ConnectionManager::instance()->removeConnection(client);
+
+    emit peerInfoUpdated();
+    d->callPeerConnector();
+}
+
+void TorrentClient::peerPiecesAvailable(const QBitArray &pieces)
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+
+    // Find the peer in our list of announced peers. If it's there,
+    // then we can use the piece list into to gather statistics that
+    // help us decide what peers to connect to.
+    TorrentPeer *peer = 0;
+    QList<TorrentPeer *>::Iterator it = d->peers.begin();
+    while (it != d->peers.end()) {
+        if ((*it)->address == client->peerAddress() && (*it)->port == client->peerPort()) {
+            peer = *it;
+            break;
+        }
+        ++it;
+    }
+
+    // If the peer is a seed, and we are in seeding mode, then the
+    // peer is uninteresting.
+    if (pieces.count(true) == d->pieceCount) {
+        if (peer)
+            peer->seed = true;
+        emit peerInfoUpdated();
+        if (d->state == Seeding) {
+            client->abort();
+            return;
+        } else {
+            if (peer)
+                peer->interesting = true;
+            if ((client->peerWireState() & PeerWireClient::InterestedInPeer) == 0)
+                client->sendInterested();
+            d->callScheduler();
+            return;
+        }
+    }
+
+    // Update our list of available pieces.
+    if (peer) {
+        peer->pieces = pieces;
+        peer->numCompletedPieces = pieces.count(true);
+    }
+
+    // Check for interesting pieces, and tell the peer whether we are
+    // interested or not.
+    bool interested = false;
+    int piecesSize = pieces.size();
+    for (int pieceIndex = 0; pieceIndex < piecesSize; ++pieceIndex) {
+        if (!pieces.testBit(pieceIndex))
+            continue;
+        if (!d->completedPieces.testBit(pieceIndex)) {
+            interested = true;
+            if ((client->peerWireState() & PeerWireClient::InterestedInPeer) == 0) {
+                if (peer)
+                    peer->interesting = true;
+                client->sendInterested();
+            }
+
+            QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.find(client);
+            int inProgress = 0;
+            while (it != d->payloads.end() && it.key() == client) {
+                if (it.value()->inProgress)
+                    inProgress += it.value()->requestedBlocks.count(true);
+                ++it;
+            }
+            if (!inProgress)
+                d->callScheduler();
+            break;
+        }
+    }
+    if (!interested && (client->peerWireState() & PeerWireClient::InterestedInPeer)) {
+        if (peer)
+            peer->interesting = false;
+        client->sendNotInterested();
+    }
+}
+
+void TorrentClient::peerRequestsBlock(int pieceIndex, int begin, int length)
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+
+    // Silently ignore requests from choked peers
+    if (client->peerWireState() & PeerWireClient::ChokingPeer)
+        return;
+
+    // Silently ignore requests for pieces we don't have.
+    if (!d->completedPieces.testBit(pieceIndex))
+        return;
+
+    // Request the block from the file manager
+    d->readIds.insert(d->fileManager.read(pieceIndex, begin, length),
+                      qobject_cast<PeerWireClient *>(sender()));
+}
+
+void TorrentClient::blockReceived(int pieceIndex, int begin, const QByteArray &data)
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+    if (data.size() == 0) {
+        client->abort();
+        return;
+    }
+
+    // Ignore it if we already have this block.
+    int blockBit = begin / BlockSize;
+    TorrentPiece *piece = d->pendingPieces.value(pieceIndex);
+    if (!piece || piece->completedBlocks.testBit(blockBit)) {
+        // Discard blocks that we already have, and fill up the pipeline.
+        requestMore(client);
+        return;
+    }
+
+    // If we are in warmup or endgame mode, cancel all duplicate
+    // requests for this block.
+    if (d->state == WarmingUp || d->state == Endgame) {
+        QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.begin();
+        while (it != d->payloads.end()) {
+            PeerWireClient *otherClient = it.key();
+            if (otherClient != client && it.value()->index == pieceIndex) {
+                if (otherClient->incomingBlocks().contains(TorrentBlock(pieceIndex, begin, data.size())))
+                    it.key()->cancelRequest(pieceIndex, begin, data.size());
+            }
+            ++it;
+        }
+    }
+
+    if (d->state != Downloading && d->state != Endgame && d->completedPieces.count(true) > 0)
+        d->setState(Downloading);
+
+    // Store this block
+    d->fileManager.write(pieceIndex, begin, data);
+    piece->completedBlocks.setBit(blockBit);
+    piece->requestedBlocks.clearBit(blockBit);
+
+    if (blocksLeftForPiece(piece) == 0) {
+        // Ask the file manager to verify the newly downloaded piece
+        d->fileManager.verifyPiece(piece->index);
+        
+        // Remove this piece from all payloads
+        QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.begin();
+        while (it != d->payloads.end()) {
+            if (!it.value() || it.value()->index == piece->index)
+                it = d->payloads.erase(it);
+            else
+                ++it;
+        }
+    }
+
+    // Fill up the pipeline.
+    requestMore(client);
+}
+
+void TorrentClient::peerWireBytesWritten(qint64 size)
+{
+    if (!d->transferRateTimer)
+        d->transferRateTimer = startTimer(RateControlTimerDelay);
+
+    d->uploadRate[0] += size;
+    d->uploadedBytes += size;
+    emit dataSent(size);
+}
+
+void TorrentClient::peerWireBytesReceived(qint64 size)
+{
+    if (!d->transferRateTimer)
+        d->transferRateTimer = startTimer(RateControlTimerDelay);
+
+    d->downloadRate[0] += size;
+    d->downloadedBytes += size;
+    emit dataSent(size);
+}
+
+int TorrentClient::blocksLeftForPiece(const TorrentPiece *piece) const
+{
+    int blocksLeft = 0;
+    int completedBlocksSize = piece->completedBlocks.size();
+    for (int i = 0; i < completedBlocksSize; ++i) {
+        if (!piece->completedBlocks.testBit(i))
+            ++blocksLeft;
+    }
+    return blocksLeft;
+}
+
+void TorrentClient::scheduleUploads()
+{
+    // Generate a list of clients sorted by their transfer
+    // speeds.  When leeching, we sort by download speed, and when
+    // seeding, we sort by upload speed. Seeds are left out; there's
+    // no use in unchoking them.
+    QList<PeerWireClient *> allClients = d->connections;
+    QMultiMap<int, PeerWireClient *> transferSpeeds;
+    foreach (PeerWireClient *client, allClients) {
+        if (client->state() == QAbstractSocket::ConnectedState
+            && client->availablePieces().count(true) != d->pieceCount) {
+            if (d->state == Seeding) {
+                transferSpeeds.insert(client->uploadSpeed(), client);
+            } else {
+                transferSpeeds.insert(client->downloadSpeed(), client);
+            }
+        }
+    }
+
+    // Unchoke the top 'MaxUploads' downloaders (peers that we are
+    // uploading to) and choke all others.
+    int maxUploaders = MaxUploads;
+    QMapIterator<int, PeerWireClient *> it(transferSpeeds);
+    it.toBack();
+    while (it.hasPrevious()) {
+        PeerWireClient *client = it.previous().value();
+        bool interested = (client->peerWireState() & PeerWireClient::PeerIsInterested);
+
+        if (maxUploaders) {
+            allClients.removeAll(client);
+            if (client->peerWireState() & PeerWireClient::ChokingPeer)
+                client->unchokePeer();
+            --maxUploaders;
+            continue;
+        }
+
+        if ((client->peerWireState() & PeerWireClient::ChokingPeer) == 0) {
+            if ((qrand() % 10) == 0) 
+                client->abort();
+            else
+                client->chokePeer();
+            allClients.removeAll(client);
+        }
+        if (!interested)
+            allClients.removeAll(client);
+    }
+
+    // Only interested peers are left in allClients. Unchoke one
+    // random peer to allow it to compete for a position among the
+    // downloaders.  (This is known as an "optimistic unchoke".)
+    if (!allClients.isEmpty()) {
+        PeerWireClient *client = allClients[qrand() % allClients.size()];
+        if (client->peerWireState() & PeerWireClient::ChokingPeer)
+            client->unchokePeer();
+    }
+}
+
+void TorrentClient::scheduleDownloads()
+{
+    d->schedulerCalled = false;
+
+    if (d->state == Stopping || d->state == Paused || d->state == Idle)
+        return;
+
+    // Check what each client is doing, and assign payloads to those
+    // who are either idle or done.
+    foreach (PeerWireClient *client, d->connections)
+        schedulePieceForClient(client);
+}
+
+void TorrentClient::schedulePieceForClient(PeerWireClient *client)
+{
+    // Only schedule connected clients.
+    if (client->state() != QTcpSocket::ConnectedState)
+        return;
+
+    // The peer has choked us; try again later.
+    if (client->peerWireState() & PeerWireClient::ChokedByPeer)
+        return;
+
+    // Make a list of all the client's pending pieces, and count how
+    // many blocks have been requested.
+    QList<int> currentPieces;
+    bool somePiecesAreNotInProgress = false;
+    TorrentPiece *lastPendingPiece = 0;
+    QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.find(client);
+    while (it != d->payloads.end() && it.key() == client) {
+        lastPendingPiece = it.value();
+        if (lastPendingPiece->inProgress) {
+            currentPieces << lastPendingPiece->index;
+        } else {
+            somePiecesAreNotInProgress = true;
+        }
+        ++it;
+    }
+
+    // Skip clients that already have too many blocks in progress.
+    if (client->incomingBlocks().size() >= ((d->state == Endgame || d->state == WarmingUp)
+                                            ? MaxBlocksInMultiMode : MaxBlocksInProgress))
+        return;
+
+    // If all pieces are in progress, but we haven't filled up our
+    // block requesting quota, then we need to schedule another piece.
+    if (!somePiecesAreNotInProgress || client->incomingBlocks().size() > 0)
+        lastPendingPiece = 0;
+    TorrentPiece *piece = lastPendingPiece;
+
+    // In warmup state, all clients request blocks from the same pieces.
+    if (d->state == WarmingUp && d->pendingPieces.size() >= 4) {
+        piece = d->payloads.value(client);
+        if (!piece) {
+            QList<TorrentPiece *> values = d->pendingPieces.values();
+            piece = values.value(qrand() % values.size());
+            piece->inProgress = true;
+            d->payloads.insert(client, piece);
+        }
+        if (piece->completedBlocks.count(false) == client->incomingBlocks().size())
+            return;
+    }
+
+    // If no pieces are currently in progress, schedule a new one.
+    if (!piece) {
+        // Build up a list of what pieces that we have not completed
+        // are available to this client.
+        QBitArray incompletePiecesAvailableToClient = d->incompletePieces;
+
+        // Remove all pieces that are marked as being in progress
+        // already (i.e., pieces that this or other clients are
+        // already waiting for). A special rule applies to warmup and
+        // endgame mode; there, we allow several clients to request
+        // the same piece. In endgame mode, this only applies to
+        // clients that are currently uploading (more than 1.0KB/s).
+        if ((d->state == Endgame && client->uploadSpeed() < 1024) || d->state != WarmingUp) {
+            QMap<int, TorrentPiece *>::ConstIterator it = d->pendingPieces.constBegin();
+            while (it != d->pendingPieces.constEnd()) {
+                if (it.value()->inProgress)
+                    incompletePiecesAvailableToClient.clearBit(it.key());
+                ++it;
+            }
+        }
+
+        // Remove all pieces that the client cannot download.
+        incompletePiecesAvailableToClient &= client->availablePieces();
+
+        // Remove all pieces that this client has already requested.
+        foreach (int i, currentPieces)
+            incompletePiecesAvailableToClient.clearBit(i);
+
+        // Only continue if more pieces can be scheduled. If no pieces
+        // are available and no blocks are in progress, just leave
+        // the connection idle; it might become interesting later.
+        if (incompletePiecesAvailableToClient.count(true) == 0)
+            return;
+
+        // Check if any of the partially completed pieces can be
+        // recovered, and if so, pick a random one of them.
+        QList<TorrentPiece *> partialPieces;
+        QMap<int, TorrentPiece *>::ConstIterator it = d->pendingPieces.constBegin();
+        while (it != d->pendingPieces.constEnd()) {
+            TorrentPiece *tmp = it.value();
+            if (incompletePiecesAvailableToClient.testBit(it.key())) {
+                if (!tmp->inProgress || d->state == WarmingUp || d->state == Endgame) {
+                    partialPieces << tmp;
+                    break;
+                }
+            }
+            ++it;
+        }
+        if (!partialPieces.isEmpty())
+            piece = partialPieces.value(qrand() % partialPieces.size());
+
+        if (!piece) {
+            // Pick a random piece 3 out of 4 times; otherwise, pick either
+            // one of the most common or the least common pieces available,
+            // depending on the state we're in.
+            int pieceIndex = 0;
+            if (d->state == WarmingUp || (qrand() & 4) == 0) {
+                int *occurrences = new int[d->pieceCount];
+                memset(occurrences, 0, d->pieceCount * sizeof(int));
+                
+                // Count how many of each piece are available.
+                foreach (PeerWireClient *peer, d->connections) {
+                    QBitArray peerPieces = peer->availablePieces();
+                    int peerPiecesSize = peerPieces.size();
+                    for (int i = 0; i < peerPiecesSize; ++i) {
+                        if (peerPieces.testBit(i))
+                            ++occurrences[i];
+                    }
+                }
+
+                // Find the rarest or most common pieces.
+                int numOccurrences = d->state == WarmingUp ? 0 : 99999;
+                QList<int> piecesReadyForDownload;
+                for (int i = 0; i < d->pieceCount; ++i) {
+                    if (d->state == WarmingUp) {
+                        // Add common pieces
+                        if (occurrences[i] >= numOccurrences
+                            && incompletePiecesAvailableToClient.testBit(i)) {
+                            if (occurrences[i] > numOccurrences)
+                                piecesReadyForDownload.clear();
+                            piecesReadyForDownload.append(i);
+                            numOccurrences = occurrences[i];
+                        }
+                    } else {
+                        // Add rare pieces
+                        if (occurrences[i] <= numOccurrences
+                            && incompletePiecesAvailableToClient.testBit(i)) {
+                            if (occurrences[i] < numOccurrences)
+                                piecesReadyForDownload.clear();
+                            piecesReadyForDownload.append(i);
+                            numOccurrences = occurrences[i];
+                        }
+                    }
+                }
+
+                // Select one piece randomly
+                pieceIndex = piecesReadyForDownload.at(qrand() % piecesReadyForDownload.size());
+                delete [] occurrences;
+            } else {
+                // Make up a list of available piece indices, and pick
+                // a random one.
+                QList<int> values;
+                int incompletePiecesAvailableToClientSize = incompletePiecesAvailableToClient.size();
+                for (int i = 0; i < incompletePiecesAvailableToClientSize; ++i) {
+                    if (incompletePiecesAvailableToClient.testBit(i))
+                        values << i;
+                }
+                pieceIndex = values.at(qrand() % values.size());
+            }
+
+            // Create a new TorrentPiece and fill in all initial
+            // properties.
+            piece = new TorrentPiece;
+            piece->index = pieceIndex;
+            piece->length = d->fileManager.pieceLengthAt(pieceIndex);
+            int numBlocks = piece->length / BlockSize;
+            if (piece->length % BlockSize)
+                ++numBlocks;
+            piece->completedBlocks.resize(numBlocks);
+            piece->requestedBlocks.resize(numBlocks);
+            d->pendingPieces.insert(pieceIndex, piece);
+        }
+
+        piece->inProgress = true;
+        d->payloads.insert(client, piece);
+    }
+
+    // Request more blocks from all pending pieces.
+    requestMore(client);
+}
+
+void TorrentClient::requestMore(PeerWireClient *client)
+{
+    // Make a list of all pieces this client is currently waiting for,
+    // and count the number of blocks in progress.
+    QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.find(client);
+    int numBlocksInProgress = client->incomingBlocks().size();
+    QList<TorrentPiece *> piecesInProgress;
+    while (it != d->payloads.end() && it.key() == client) {
+        TorrentPiece *piece = it.value();
+        if (piece->inProgress || (d->state == WarmingUp || d->state == Endgame))
+            piecesInProgress << piece;
+        ++it;
+    }
+
+    // If no pieces are in progress, call the scheduler.
+    if (piecesInProgress.isEmpty() && d->incompletePieces.count(true)) {
+        d->callScheduler();
+        return;
+    }
+
+    // If too many pieces are in progress, there's nothing to do.
+    int maxInProgress = ((d->state == Endgame || d->state == WarmingUp)
+                         ? MaxBlocksInMultiMode : MaxBlocksInProgress);
+    if (numBlocksInProgress == maxInProgress)
+        return;
+    
+    // Starting with the first piece that we're waiting for, request
+    // blocks until the quota is filled up.
+    foreach (TorrentPiece *piece, piecesInProgress) {
+        numBlocksInProgress += requestBlocks(client, piece, maxInProgress - numBlocksInProgress);
+        if (numBlocksInProgress == maxInProgress)
+            break;
+    }
+
+    // If we still didn't fill up the quota, we need to schedule more
+    // pieces.
+    if (numBlocksInProgress < maxInProgress && d->state != WarmingUp)
+        d->callScheduler();
+}
+
+int TorrentClient::requestBlocks(PeerWireClient *client, TorrentPiece *piece, int maxBlocks)
+{
+    // Generate the list of incomplete blocks for this piece.
+    QVector<int> bits;
+    int completedBlocksSize = piece->completedBlocks.size();
+    for (int i = 0; i < completedBlocksSize; ++i) {
+        if (!piece->completedBlocks.testBit(i) && !piece->requestedBlocks.testBit(i))
+            bits << i;
+    }
+
+    // Nothing more to request.
+    if (bits.size() == 0) {
+        if (d->state != WarmingUp && d->state != Endgame)
+            return 0;
+        bits.clear();
+        for (int i = 0; i < completedBlocksSize; ++i) {
+            if (!piece->completedBlocks.testBit(i))
+                bits << i;
+        }
+    }
+
+    if (d->state == WarmingUp || d->state == Endgame) {
+        // By randomizing the list of blocks to request, we
+        // significantly speed up the warmup and endgame modes, where
+        // the same blocks are requested from multiple peers. The
+        // speedup comes from an increased chance of receiving
+        // different blocks from the different peers.
+        for (int i = 0; i < bits.size(); ++i) {
+            int a = qrand() % bits.size();
+            int b = qrand() % bits.size();
+            int tmp = bits[a];
+            bits[a] = bits[b];
+            bits[b] = tmp;
+        }
+    }
+
+    // Request no more blocks than we've been asked to.
+    int blocksToRequest = qMin(maxBlocks, bits.size());
+
+    // Calculate the offset and size of each block, and send requests.
+    for (int i = 0; i < blocksToRequest; ++i) {
+        int blockSize = BlockSize;
+        if ((piece->length % BlockSize) && bits.at(i) == completedBlocksSize - 1)
+            blockSize = piece->length % BlockSize;
+        client->requestBlock(piece->index, bits.at(i) * BlockSize, blockSize);
+        piece->requestedBlocks.setBit(bits.at(i));
+    }
+
+    return blocksToRequest;
+}
+
+void TorrentClient::peerChoked()
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+    if (!client)
+        return;
+
+    // When the peer chokes us, we immediately forget about all blocks
+    // we've requested from it. We also remove the piece from out
+    // payload, making it available to other clients.
+    QMultiMap<PeerWireClient *, TorrentPiece *>::Iterator it = d->payloads.find(client);
+    while (it != d->payloads.end() && it.key() == client) {
+        it.value()->inProgress = false;
+        it.value()->requestedBlocks.fill(false);
+        it = d->payloads.erase(it);
+    }
+}
+
+void TorrentClient::peerUnchoked()
+{
+    PeerWireClient *client = qobject_cast<PeerWireClient *>(sender());
+    if (!client)
+        return;
+
+    // We got unchoked, which means we can request more blocks.
+    if (d->state != Seeding)
+        d->callScheduler();
+}
+
+void TorrentClient::addToPeerList(const QList<TorrentPeer> &peerList)
+{
+    // Add peers we don't already know of to our list of peers.
+    QList<QHostAddress> addresses =  QNetworkInterface::allAddresses();
+    foreach (TorrentPeer peer, peerList) {
+        if (addresses.contains(peer.address)
+            && peer.port == TorrentServer::instance()->serverPort()) {
+            // Skip our own server.
+            continue;
+        }
+		
+        bool known = false;
+        foreach (TorrentPeer *knownPeer, d->peers) {
+            if (knownPeer->port == peer.port
+                && knownPeer->address == peer.address) {
+                known = true;
+                break;
+            }
+        }
+        if (!known) {
+            TorrentPeer *newPeer = new TorrentPeer;
+            *newPeer = peer;
+            newPeer->interesting = true;
+            newPeer->seed = false;
+            newPeer->lastVisited = 0;
+            newPeer->connectStart = 0;
+            newPeer->connectTime = 999999;
+            newPeer->pieces.resize(d->pieceCount);
+            newPeer->numCompletedPieces = 0;
+            d->peers << newPeer;
+        }
+    }
+
+    // If we've got more peers than we can connect to, we remove some
+    // of the peers that have no (or low) activity.
+    int maxPeers = ConnectionManager::instance()->maxConnections() * 3;
+    if (d->peers.size() > maxPeers) {
+        // Find what peers are currently connected & active
+        QSet<TorrentPeer *> activePeers;
+        foreach (TorrentPeer *peer, d->peers) {
+            foreach (PeerWireClient *client, d->connections) {
+                if (client->peer() == peer && (client->downloadSpeed() + client->uploadSpeed()) > 1024)
+                    activePeers << peer;
+            }
+        }
+
+        // Remove inactive peers from the peer list until we're below
+        // the max connections count.
+        QList<int> toRemove;
+        for (int i = 0; i < d->peers.size() && (d->peers.size() - toRemove.size()) > maxPeers; ++i) {
+            if (!activePeers.contains(d->peers.at(i)))
+                toRemove << i;
+        }
+        QListIterator<int> toRemoveIterator(toRemove);
+        toRemoveIterator.toBack();
+        while (toRemoveIterator.hasPrevious())
+            d->peers.removeAt(toRemoveIterator.previous());
+
+        // If we still have too many peers, remove the oldest ones.
+        while (d->peers.size() > maxPeers)
+            d->peers.takeFirst();
+    }
+
+    if (d->state != Paused && d->state != Stopping && d->state != Idle) {
+        if (d->state == Searching || d->state == WarmingUp)
+            connectToPeers();
+        else
+            d->callPeerConnector();
+    }
+}
+
+void TorrentClient::trackerStopped()
+{
+    d->setState(Idle);
+    emit stopped();
+}
+
+void TorrentClient::updateProgress(int progress)
+{
+    if (progress == -1 && d->pieceCount > 0) {
+        int newProgress = (d->completedPieces.count(true) * 100) / d->pieceCount;
+        if (d->lastProgressValue != newProgress) {
+            d->lastProgressValue = newProgress;
+            emit progressUpdated(newProgress);
+        }
+    } else if (d->lastProgressValue != progress) {
+        d->lastProgressValue = progress;
+        emit progressUpdated(progress);
+    }
+}