TokenServer & copyClosureTokenServer,

    TokenServer & copyClosureTokenServer, counter & bytesSent,

    for (auto & p : missing)
        bytesSent += store->queryPathInfo(p).narSize;

    FdSource & from, FdSink & to, const PathSet & paths)

    FdSource & from, FdSink & to, const PathSet & paths, counter & bytesReceived)

    for (auto & p : paths)
        bytesReceived += store->queryPathInfo(p).narSize;

    counter & nrStepsBuilding, counter & nrStepsCopyingTo, counter & nrStepsCopyingFrom)

    counter & nrStepsBuilding, counter & nrStepsCopyingTo, counter & nrStepsCopyingFrom,
    counter & bytesSent, counter & bytesReceived)

    printMsg(lvlDebug, format("sending closure of ‘%1%’ to ‘%2%’") % drvPath % sshName);
    {

    if (sshName != "localhost") {
        printMsg(lvlDebug, format("sending closure of ‘%1%’ to ‘%2%’") % drvPath % sshName);

        copyClosureTo(store, from, to, inputs, copyClosureTokenServer);

        copyClosureTo(store, from, to, inputs, copyClosureTokenServer, bytesSent);

    printMsg(lvlDebug, format("copying outputs of ‘%1%’ from ‘%2%’") % drvPath % sshName);
    PathSet outputs;
    for (auto & output : drv.outputs)
        outputs.insert(output.second.path);
    {

    if (sshName != "localhost") {
        printMsg(lvlDebug, format("copying outputs of ‘%1%’ from ‘%2%’") % drvPath % sshName);
        PathSet outputs;
        for (auto & output : drv.outputs)
            outputs.insert(output.second.path);

        copyClosureFrom(store, from, to, outputs);

        copyClosureFrom(store, from, to, outputs, bytesReceived);

    counter & nrStepsBuilding, counter & nrStepsCopyingTo, counter & nrStepsCopyingFrom);

    counter & nrStepsBuilding, counter & nrStepsCopyingTo, counter & nrStepsCopyingFrom,
    counter & bytesSent, counter & bytesReceived);

typedef std::atomic<unsigned int> counter;

typedef std::atomic<unsigned long> counter;

    counter bytesSent{0};
    counter bytesReceived{0};

                result, nrStepsBuilding, nrStepsCopyingTo, nrStepsCopyingFrom);

                result, nrStepsBuilding, nrStepsCopyingTo, nrStepsCopyingFrom,
                bytesSent, bytesReceived);

        root.attr("bytesSent", bytesSent);
        root.attr("bytesReceived", bytesReceived);

    gauge("hydra.queue.bytes_sent", $json->{bytesSent});
    gauge("hydra.queue.bytes_received", $json->{bytesReceived});