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#include <QtCore/QDebug>
#include "discoverer.h"
Discoverer::Discoverer(const QUuid &uuid, uint port, const QString &serviceName, QObject *parent) :
QObject(parent), _folderUuid(uuid), _hostUuid(QUuid::createUuid()),
_serviceName(serviceName), _port(port),
_mtime(), _mtimeChanged(false),
_receiver(new QUdpSocket(this)), _sender(new QUdpSocket(this)),
_netConfig(new QNetworkConfigurationManager(this)),
_timer(new QTimer(this))
{
connect(_receiver, SIGNAL(readyRead()), SLOT(handleDataAvailable()));
if (!_receiver->bind(servicePort, QUdpSocket::ShareAddress)) {
qWarning() << "Failed to bind to discoverer port" << servicePort;
}
connect(_netConfig, SIGNAL(onlineStateChanged(bool)), SLOT(handleOnlineStateChanged(bool)));
connect(_timer, SIGNAL(timeout()), SLOT(handleTimerTimeout()));
_timer->setSingleShot(true);
_timer->setTimerType(Qt::VeryCoarseTimer);
if (_netConfig->isOnline() ||
_netConfig->allConfigurations(QNetworkConfiguration::Defined).empty()) {
// Either only, or _netConfig has no configs so it is useless.
qDebug() << "Start timer";
_timer->start(activeBroadcastInterval * 1000);
} else {
qDebug() << "I am NOT online";
}
}
void Discoverer::setLastModifiedTime(const QDateTime& dateTime)
{
_mtime = dateTime;
if (_knownHosts.empty()) {
// Idle mode: do nothing.
} else {
// Active mode
switchToActiveMode();
}
_mtimeChanged = true;
}
QByteArray Discoverer::encodeMessage() const
{
QByteArray ba;
QByteArray hostUuid = _hostUuid.toString().toLatin1();
QByteArray folderUuid = _folderUuid.toString().toLatin1();
QByteArray serviceNameUtf8 = _serviceName.toUtf8();
Message msg;
Q_ASSERT(hostUuid.length() == sizeof(msg.hostUuid));
Q_ASSERT(folderUuid.length() == sizeof(msg.folderUuid));
ba.reserve(sizeof(msg) + serviceNameUtf8.size());
msg.mtime = _mtime.toTime_t();
strncpy(msg.hostUuid, hostUuid.data(), sizeof(msg.hostUuid));
msg.port = _port;
strncpy(msg.folderUuid, folderUuid.data(), sizeof(msg.folderUuid));
ba.append(reinterpret_cast<char*>(&msg), sizeof(msg));
ba.append(serviceNameUtf8);
return ba;
}
void Discoverer::switchToActiveMode()
{
if (!_timer->isActive() || _timer->interval() > activeBroadcastInterval * 1000) {
_timer->start(activeBroadcastInterval * 1000);
}
}
void Discoverer::broadcastMessage()
{
_sender->writeDatagram(encodeMessage(), QHostAddress::Broadcast, servicePort);
_lastBroadcast = QDateTime::currentDateTime();
_mtimeChanged = false;
qDebug() << "Broadcast message at" << _lastBroadcast;
}
void Discoverer::handleDataAvailable()
{
while (_receiver->hasPendingDatagrams()) {
QByteArray data;
QHostAddress sender;
data.resize(_receiver->pendingDatagramSize());
_receiver->readDatagram(data.data(), data.size(), &sender);
handleBroadcastMessage(sender, data);
}
}
void Discoverer::handleBroadcastMessage(const QHostAddress& sender, const QByteArray &data)
{
const char *dataPtr = data.data();
const Message *msg = reinterpret_cast<const Message*>(dataPtr);
QString serviceName = QString::fromUtf8(&dataPtr[sizeof(Message)]);
char uuidData[sizeof(msg->hostUuid)];
strncpy(uuidData, msg->hostUuid, sizeof(uuidData));
QUuid hostUuid(QString::fromLatin1(uuidData, sizeof(uuidData)));
strncpy(uuidData, msg->folderUuid, sizeof(uuidData));
QUuid folderUuid(QString::fromLatin1(uuidData, sizeof(uuidData)));
if (hostUuid.isNull() || folderUuid.isNull()) {
qWarning() << "Null uuid";
return;
}
if (hostUuid == _hostUuid) {
// A message from myself, ignore
return;
}
if (folderUuid != _folderUuid) {
// A message not about the same folder, ignore
return;
}
qDebug() << "Got message from" << sender << msg->port;
handleHostSeen(hostUuid);
QDateTime mtime = QDateTime::fromTime_t(msg->mtime);
qDebug() << mtime << _mtime << _mtime.secsTo(mtime);
if (_mtime.secsTo(mtime) > dateTimeCompareMinDelta) {
// We are outdated, let's try to connect to them.
emit foundMoreRecentHost(sender, msg->port, mtime);
}
}
void Discoverer::handleHostSeen(const QUuid &hostUuid)
{
bool host_previously_seen = _knownHosts.contains(hostUuid);
_knownHosts[hostUuid].lastSeen = QDateTime::currentDateTime();
if (!host_previously_seen || _mtimeChanged) {
switchToActiveMode();
}
}
void Discoverer::handleTimerTimeout()
{
qDebug() << "Timer tick";
broadcastMessage();
QDateTime now = QDateTime::currentDateTime();
QHash<QUuid, HostInfo>::iterator i = _knownHosts.begin();
while (i != _knownHosts.end()) {
if (i.value().lastSeen.secsTo(now) > lostHostTimeout) {
i = _knownHosts.erase(i);
} else {
++i;
}
}
qDebug() << "Known hosts" << _knownHosts.size();
_timer->start(idleBroadcastInterval * 1000);
}
void Discoverer::handleOnlineStateChanged(bool online)
{
if (online) {
qDebug() << "Online";
switchToActiveMode();
} else {
qDebug() << "Offline";
_knownHosts.clear();
_timer->stop();
}
}
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