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// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "filedistributortrackerimpl.h"
#include "filedownloader.h"
#include <vespa/filedistribution/model/zkfacade.h>
#include <vespa/log/log.h>
LOG_SETUP(".filedistributiontrackerimpl");
using namespace filedistribution;
typedef FileDistributionModel::PeerEntries PeerEntries;
namespace asio = boost::asio;
namespace {
void
filterSelf(FileDistributionModel::PeerEntries& peers,
const std::string& hostName,
int port)
{
FileDistributionModel::PeerEntries::iterator
i = peers.begin(),
currEnd = peers.end();
while ( i != currEnd ) {
//hostName is currently used in the ip field
if (i->ip == hostName && i->port == port) {
--currEnd;
std::swap(*i, *currEnd);
} else {
++i;
}
}
peers.erase(currEnd, peers.end());
}
void resolveIPAddresses(PeerEntries& peers) {
for (auto& p: peers) {
try {
p.ip = filedistribution::lookupIPAddress(p.ip);
} catch (filedistribution::FailedResolvingHostName& e) {
LOG(info, "Failed resolving address %s", p.ip.c_str());
}
}
}
struct TrackingTask : public Scheduler::Task {
int _numTimesRescheduled;
libtorrent::tracker_request _trackerRequest;
boost::weak_ptr<libtorrent::torrent> _torrent;
std::weak_ptr<FileDownloader> _downloader;
std::shared_ptr<FileDistributionModel> _model;
TrackingTask(Scheduler& scheduler,
const libtorrent::tracker_request& trackerRequest,
const TorrentSP & torrent,
const std::weak_ptr<FileDownloader>& downloader,
const std::shared_ptr<FileDistributionModel>& model);
~TrackingTask();
//TODO: refactor
void doHandle() override;
PeerEntries getPeers(const std::shared_ptr<FileDownloader>& downloader);
void reschedule();
};
TrackingTask::TrackingTask(Scheduler& scheduler,
const libtorrent::tracker_request& trackerRequest,
const TorrentSP & torrent,
const std::weak_ptr<FileDownloader>& downloader,
const std::shared_ptr<FileDistributionModel>& model)
: Task(scheduler),
_numTimesRescheduled(0),
_trackerRequest(trackerRequest),
_torrent(torrent),
_downloader(downloader),
_model(model)
{ }
TrackingTask::~TrackingTask() {}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Winline"
//TODO: refactor
void
TrackingTask::doHandle() {
if (std::shared_ptr<FileDownloader> downloader = _downloader.lock()) {
//All torrents must be destructed before the session is destructed.
//It's okay to prevent the torrent from expiring here
//since the session can't be destructed while
//we hold a shared_ptr to the downloader.
if (TorrentSP torrent = _torrent.lock()) {
PeerEntries peers = getPeers(downloader);
if (!peers.empty()) {
torrent->session().m_io_service.dispatch(
[torrent_weak_ptr = _torrent, trackerRequest = _trackerRequest, peers = peers]() mutable {
if (auto torrent_sp = torrent_weak_ptr.lock()) {
torrent_sp->tracker_response(
trackerRequest,
libtorrent::address(),
std::list<libtorrent::address>(),
peers,
-1, -1, -1, -1, -1,
libtorrent::address(), "trackerid");
}
});
}
if (peers.size() < 5) {
reschedule();
}
}
}
}
#pragma GCC diagnostic pop
PeerEntries
TrackingTask::getPeers(const std::shared_ptr<FileDownloader>& downloader) {
std::string fileReference = downloader->infoHash2FileReference(_trackerRequest.info_hash);
const size_t recommendedMaxNumberOfPeers = 30;
PeerEntries peers = _model->getPeers(fileReference, recommendedMaxNumberOfPeers);
//currently, libtorrent stops working if it tries to connect to itself.
filterSelf(peers, downloader->_hostName, downloader->_port);
resolveIPAddresses(peers);
for (const auto& peer: peers) {
LOG(debug, "Returning peer with ip %s", peer.ip.c_str());
}
return peers;
}
void
TrackingTask::reschedule() {
if (_numTimesRescheduled < 5) {
double fudgeFactor = 0.1;
schedule(boost::posix_time::seconds(static_cast<int>(
std::pow(3., _numTimesRescheduled) + fudgeFactor)));
_numTimesRescheduled++;
}
}
} //anonymous namespace
FileDistributorTrackerImpl::FileDistributorTrackerImpl(const std::shared_ptr<FileDistributionModel>& model) :
_model(model)
{}
FileDistributorTrackerImpl::~FileDistributorTrackerImpl() {
LOG(debug, "Deconstructing FileDistributorTrackerImpl");
LockGuard guard(_mutex);
_scheduler.reset();
}
void
FileDistributorTrackerImpl::trackingRequest(
libtorrent::tracker_request& request,
const TorrentSP & torrent)
{
LockGuard guard(_mutex);
if (torrent != TorrentSP()) {
std::shared_ptr<TrackingTask> trackingTask(new TrackingTask(
*_scheduler.get(), request, torrent, _downloader, _model));
trackingTask->scheduleNow();
}
}
void asioWorker(asio::io_service& ioService)
{
while (!ioService.stopped()) {
try {
ioService.run();
} catch (const ZKConnectionLossException & e) {
LOG(info, "Connection loss in asioWorker thread, resuming. %s", e.what());
} catch (const ZKOperationTimeoutException & e) {
LOG(warning, "Operation timed out in asioWorker thread, will do quick exit to start a clean sheet. %s", e.what());
std::quick_exit(31);
}
}
}
void
FileDistributorTrackerImpl::setDownloader(const std::shared_ptr<FileDownloader>& downloader)
{
LockGuard guard(_mutex);
_scheduler.reset();
_downloader = downloader;
if (downloader) {
_scheduler.reset(new Scheduler([] (asio::io_service& ioService) { asioWorker(ioService); }));
}
}
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