torrentclient.cpp

基于QT4图形库的BT下载客户端源码

/****************************************************************************
**
** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** Licensees holding a valid Qt License Agreement may use this file in
** accordance with the rights, responsibilities and obligations
** contained therein.  Please consult your licensing agreement or
** contact [e-mail] if any conditions of this licensing
** agreement are not clear to you.
**
** Further information about Qt licensing is available at:
** http://www.trolltech.com/products/qt/licensing.html or by
** contacting [e-mail].
**
** 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 "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>

extern "C" {
#include "3rdparty/sha1.h"
}

// 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, const QByteArray &)),
            this, SLOT(sendToPeer(int, int, int, const 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(const QList<TorrentPeer> &)),
            this, SLOT(addToPeerList(const 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();
    SHA1Context sha;
    SHA1Reset(&sha);
    SHA1Input(&sha, (const unsigned char *)infoValue.constData(), infoValue.size());
    SHA1Result(&sha);
    unsigned char *digest = (unsigned char *)sha.Message_Digest;
    d->infoHash.resize(20);

    for (int i = 0; i < 5; ++i) {
#if Q_BYTE_ORDER == Q_BIG_ENDIAN
        d->infoHash[i * 4 + 3] = digest[i * 4 + 3];
        d->infoHash[i * 4 + 2] = digest[i * 4 + 2];
        d->infoHash[i * 4 + 1] = digest[i * 4 + 1];
        d->infoHash[i * 4 + 0] = digest[i * 4 + 0];
#else
        d->infoHash[i * 4 + 0] = digest[i * 4 + 3];
        d->infoHash[i * 4 + 1] = digest[i * 4 + 2];
        d->infoHash[i * 4 + 2] = digest[i * 4 + 1];
        d->infoHash[i * 4 + 3] = digest[i * 4 + 0];
#endif
    }

    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;