/**
* Get the fastest free peer, may remove dead peers.
*/
PM::IPeer* ChunkDownloader::getTheFastestFreePeer()
{
QMutexLocker locker(&this->mutex);
PM::IPeer* current = nullptr;
bool isTheNmberOfPeersHasChanged = false;
for (QMutableListIterator<PM::IPeer*> i(this->peers); i.hasNext();)
{
PM::IPeer* peer = i.next();
if (!peer->isAvailable())
{
i.remove();
this->linkedPeers.rmLink(peer);
isTheNmberOfPeersHasChanged = true;
}
else if (this->occupiedPeersDownloadingChunk.isPeerFree(peer) && (!current || peer->getSpeed() > current->getSpeed()))
current = peer;
}
if (isTheNmberOfPeersHasChanged)
emit numberOfPeersChanged();
return current;
}
void ChunkDownloader::run()
{
int deltaRead = 0;
QElapsedTimer timer;
timer.start();
this->lastTransferStatus = QUEUED;
try
{
QSharedPointer<FM::IDataWriter> writer = this->chunk->getDataWriter();
static const int SOCKET_TIMEOUT = SETTINGS.get<quint32>("socket_timeout");
static const int TIME_PERIOD_CHOOSE_ANOTHER_PEER = 1000.0 * SETTINGS.get<double>("time_recheck_chunk_factor") * SETTINGS.get<quint32>("chunk_size") / SETTINGS.get<quint32>("lan_speed");
static const int BUFFER_SIZE = SETTINGS.get<quint32>("buffer_size_writing");
char buffer[BUFFER_SIZE];
const int initialKnownBytes = this->chunk->getKnownBytes();
int bytesToRead = this->chunkSize - initialKnownBytes;
int bytesToWrite = 0;
int bytesWritten = 0;
forever
{
this->mutex.lock();
if (!this->downloading)
{
L_DEBU(QString("Downloading aborted, chunk : %1%2").arg(this->chunk->toStringLog()).arg(this->chunk->isComplete() ? "" : " Not complete!"));
this->closeTheSocket = true; // Because some garbage from the remote uploader will continue to come in this socket.
this->mutex.unlock();
break;
}
this->mutex.unlock();
int bytesRead = this->socket->read(buffer + bytesToWrite, bytesToRead < BUFFER_SIZE - bytesToWrite ? bytesToRead : BUFFER_SIZE - bytesToWrite);
bytesToRead -= bytesRead;
if (bytesRead == 0)
{
if (!this->socket->waitForReadyRead(SOCKET_TIMEOUT))
{
L_WARN(QString("Connection dropped, error = %1, bytesAvailable = %2").arg(socket->errorString()).arg(socket->bytesAvailable()));
this->closeTheSocket = true;
this->lastTransferStatus = TRANSFER_ERROR;
break;
}
continue;
}
else if (bytesRead == -1)
{
L_WARN(QString("Socket : cannot receive data : %1").arg(this->chunk->toStringLog()));
this->closeTheSocket = true;
this->lastTransferStatus = TRANSFER_ERROR;
break;
}
deltaRead += bytesRead;
bytesToWrite += bytesRead;
if (timer.elapsed() > TIME_PERIOD_CHOOSE_ANOTHER_PEER)
{
this->currentDownloadingPeer->setSpeed(deltaRead / timer.elapsed() * 1000);
L_DEBU(QString("Check for a better peer for the chunk: %1, current peer: %2 . . .").arg(this->chunk->toStringLog()).arg(this->currentDownloadingPeer->toStringLog()));
timer.start();
deltaRead = 0;
// If a another peer exists and its speed is greater than our by a factor 'switch_to_another_peer_factor'
// then we will try to switch to this peer.
PM::IPeer* peer = this->getTheFastestFreePeer();
if (
peer &&
peer != this->currentDownloadingPeer &&
peer->getSpeed() / SETTINGS.get<double>("switch_to_another_peer_factor") > this->currentDownloadingPeer->getSpeed()
)
{
L_DEBU(QString("Switch to a better peer: %1").arg(peer->toStringLog()));
this->closeTheSocket = true; // We ask to close the socket to avoid to get garbage data.
break;
}
}
// If the buffer is full or there is no more byte to read.
if (bytesToWrite == BUFFER_SIZE || bytesToRead == 0)
{
writer->write(buffer, bytesToWrite);
bytesWritten += bytesToWrite;
bytesToWrite = 0;
}
this->transferRateCalculator.addData(bytesRead);
if (initialKnownBytes + bytesWritten >= this->chunkSize)
break;
}
}
catch(FM::FileResetException)
{
L_DEBU("FileResetException");
this->closeTheSocket = true;
this->lastTransferStatus = FILE_NON_EXISTENT;
}
catch(FM::ChunkDataUnknownException)
{
L_DEBU("ChunkDataUnknownException");
this->closeTheSocket = true;
this->lastTransferStatus = UNABLE_TO_OPEN_THE_FILE;
}
catch(FM::UnableToOpenFileInWriteModeException)
{
L_DEBU("UnableToOpenFileInWriteModeException");
this->closeTheSocket = true;
this->lastTransferStatus = UNABLE_TO_OPEN_THE_FILE;
}
catch(FM::IOErrorException&)
{
L_DEBU("IOErrorException");
this->closeTheSocket = true;
this->lastTransferStatus = FILE_IO_ERROR;
}
catch (FM::ChunkDeletedException&)
{
L_DEBU("ChunkDeletedException");
this->closeTheSocket = true;
this->lastTransferStatus = FILE_NON_EXISTENT;
}
catch (FM::TryToWriteBeyondTheEndOfChunkException&)
{
L_DEBU("TryToWriteBeyondTheEndOfChunkException");
this->closeTheSocket = true;
this->lastTransferStatus = GOT_TOO_MUCH_DATA;
}
catch (FM::hashMissmatchException)
{
static const quint32 BLOCK_DURATION = SETTINGS.get<quint32>("block_duration_corrupted_data");
L_USER(QString(tr("Corrupted data received for the file \"%1\" from peer %2. Peer blocked for %3 ms")).arg(this->chunk->getFilePath()).arg(this->currentDownloadingPeer->getNick()).arg(BLOCK_DURATION));
/*: A reason why the user has been blocked */
this->currentDownloadingPeer->block(BLOCK_DURATION, tr("Has sent corrupted data"));
this->closeTheSocket = true;
this->lastTransferStatus = HASH_MISSMATCH;
}
if (timer.elapsed() > MINIMUM_DELTA_TIME_TO_COMPUTE_SPEED)
this->currentDownloadingPeer->setSpeed(deltaRead / timer.elapsed() * 1000);
this->socket->setReadBufferSize(0);
this->socket->moveToThread(this->mainThread);
}