torrentclient.cpp Example File
network/torrent/torrentclient.cpp
/****************************************************************************
**
** Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation 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 "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;
}
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)
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.setUploadCount(d->uploadedBytes);
d->trackerClient.setDownloadCount(d->downloadedBytes);
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.start(d->metaInfo);
}
} 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()
&& (rand() % (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(rand() % 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(const QBitArray &)),
this, SLOT(peerPiecesAvailable(const QBitArray &)));
connect(client, SIGNAL(blockRequested(int, int, int)),
this, SLOT(peerRequestsBlock(int, int, int)));
connect(client, SIGNAL(blockReceived(int, int, const QByteArray &)),
this, SLOT(blockReceived(int, int, const 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 ((rand() % 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[rand() % 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(rand() % 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(rand() % 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 || (rand() & 4) == 0) {
int *occurrances = new int[d->pieceCount];
memset(occurrances, 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))
++occurrances[i];
}
}
// Find the rarest or most common pieces.
int numOccurrances = d->state == WarmingUp ? 0 : 99999;
QList<int> piecesReadyForDownload;
for (int i = 0; i < d->pieceCount; ++i) {
if (d->state == WarmingUp) {
// Add common pieces
if (occurrances[i] >= numOccurrances
&& incompletePiecesAvailableToClient.testBit(i)) {
if (occurrances[i] > numOccurrances)
piecesReadyForDownload.clear();
piecesReadyForDownload.append(i);
numOccurrances = occurrances[i];
}
} else {
// Add rare pieces
if (occurrances[i] <= numOccurrances
&& incompletePiecesAvailableToClient.testBit(i)) {
if (occurrances[i] < numOccurrances)
piecesReadyForDownload.clear();
piecesReadyForDownload.append(i);
numOccurrances = occurrances[i];
}
}
}
// Select one piece randomly
pieceIndex = piecesReadyForDownload.at(rand() % piecesReadyForDownload.size());
delete [] occurrances;
} 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(rand() % 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 = rand() % bits.size();
int b = rand() % 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.
foreach (TorrentPeer peer, peerList) {
if (peer.address == TorrentServer::instance()->serverAddress()
&& peer.port == TorrentServer::instance()->serverPort())
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);
}
}
