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    41 

    42 #include "peerwireclient.h"

    43 #include "ratecontroller.h"

    44 

    45 #include <QtCore>

    46 

    47 Q_GLOBAL_STATIC(RateController, rateController)

    48 

    49 RateController *RateController::instance()

    50 {

    51     return rateController();

    52 }

    53 

    54 void RateController::addSocket(PeerWireClient *socket)

    55 {

    56     connect(socket, SIGNAL(readyToTransfer()), this, SLOT(scheduleTransfer()));

    57     socket->setReadBufferSize(downLimit * 4);

    58     sockets << socket;

    59     scheduleTransfer();

    60 }

    61 

    62 void RateController::removeSocket(PeerWireClient *socket)

    63 {

    64     disconnect(socket, SIGNAL(readyToTransfer()), this, SLOT(scheduleTransfer()));

    65     socket->setReadBufferSize(0);

    66     sockets.remove(socket);

    67 }

    68 

    69 void RateController::setDownloadLimit(int bytesPerSecond)

    70 {

    71     downLimit = bytesPerSecond;

    72     foreach (PeerWireClient *socket, sockets)

    73         socket->setReadBufferSize(downLimit * 4);

    74 }

    75 

    76 void RateController::scheduleTransfer()

    77 {

    78     if (transferScheduled)

    79         return;

    80     transferScheduled = true;

    81     QTimer::singleShot(50, this, SLOT(transfer()));

    82 }

    83 

    84 void RateController::transfer()

    85 {

    86     transferScheduled = false;

    87     if (sockets.isEmpty())

    88         return;

    89 

    90     int msecs = 1000;

    91     if (!stopWatch.isNull())

    92         msecs = qMin(msecs, stopWatch.elapsed());

    93 

    94     qint64 bytesToWrite = (upLimit * msecs) / 1000;

    95     qint64 bytesToRead = (downLimit * msecs) / 1000;

    96     if (bytesToWrite == 0 && bytesToRead == 0) {

    97         scheduleTransfer();

    98         return;

    99     }

   100 

   101     QSet<PeerWireClient *> pendingSockets;

   102     foreach (PeerWireClient *client, sockets) {

   103         if (client->canTransferMore())

   104             pendingSockets << client;

   105     }

   106     if (pendingSockets.isEmpty())

   107         return;

   108 

   109     stopWatch.start();

   110 

   111     bool canTransferMore;

   112     do {

   113         canTransferMore = false;

   114         qint64 writeChunk = qMax<qint64>(1, bytesToWrite / pendingSockets.size());

   115         qint64 readChunk = qMax<qint64>(1, bytesToRead / pendingSockets.size());

   116 

   117         QSetIterator<PeerWireClient *> it(pendingSockets);

   118         while (it.hasNext() && (bytesToWrite > 0 || bytesToRead > 0)) {

   119             PeerWireClient *socket = it.next();

   120             if (socket->state() != QAbstractSocket::ConnectedState) {

   121                 pendingSockets.remove(socket);

   122                 continue;

   123             }

   124 

   125             bool dataTransferred = false;

   126             qint64 available = qMin<qint64>(socket->socketBytesAvailable(), readChunk);

   127             if (available > 0) {

   128                 qint64 readBytes = socket->readFromSocket(qMin<qint64>(available, bytesToRead));

   129                 if (readBytes > 0) {

   130                     bytesToRead -= readBytes;

   131                     dataTransferred = true;

   132                 }

   133             }

   134 

   135             if (upLimit * 2 > socket->bytesToWrite()) {

   136                 qint64 chunkSize = qMin<qint64>(writeChunk, bytesToWrite);

   137                 qint64 toWrite = qMin(upLimit * 2 - socket->bytesToWrite(), chunkSize);

   138                 if (toWrite > 0) {

   139                     qint64 writtenBytes = socket->writeToSocket(toWrite);

   140                     if (writtenBytes > 0) {

   141                         bytesToWrite -= writtenBytes;

   142                         dataTransferred = true;

   143                     }

   144                 }

   145             }

   146 

   147             if (dataTransferred && socket->canTransferMore())

   148                 canTransferMore = true;

   149             else

   150                 pendingSockets.remove(socket);

   151         }

   152     } while (canTransferMore && (bytesToWrite > 0 || bytesToRead > 0) && !pendingSockets.isEmpty());

   153 

   154     if (canTransferMore || bytesToWrite == 0 || bytesToRead == 0)

   155         scheduleTransfer();

   156 }