Method ProcessDataPacket

library/cpp/netliba/v12/udp_host.cpp:1136–1275

    }

    bool TUdpHost::ProcessDataPacket(const EUdpCmd cmd, const char* pktData, const char* pktEnd,
                                     TAutoPtr<TUdpRecvPacket> recvBuf, const TTransfer& transfer, const TOptionsVector& opt) {
        Y_ASSERT(IsDataCmd(cmd));
        Y_ASSERT(pktData <= pktEnd);

        int packetId;
        int ackTos;
        ui8 netlibaColor;

        if (!ReadPacketHeaderTail(&pktData, pktEnd, &packetId, &ackTos, &netlibaColor, opt) || packetId < 0 || !IsValidTos(ackTos)) {
            Y_ASSERT(false);
            return false;
        }

        TConnection* connection = CheckedCast<TConnection*>(transfer.Connection.Get());
        Connections.InsertToActive(connection);
        bool isFailed = false, isCanceled = false;
        if (connection->IsRecvCompleted(transfer.Id, &isFailed, &isCanceled)) {
            Y_ASSERT(!connection->GetRecvQueue().Has(transfer.Id));

            if (isCanceled) {
                SendAckCanceled(S, connection, transfer.Id, packetId, DefaultTos.GetAckTos());
            } else if (isFailed) {
                ; // TODO: we cannot continue, at least we must reset everything, maybe ignore?
            } else {
                SendAckComplete(S, connection, transfer.Id, packetId, DefaultTos.GetAckTos()); // TODO: where to get ack tos?
            }
            return true;
        }

        std::pair<TUdpInTransfer*, bool> p = connection->InsertRecvTransfer(transfer.Id);
        if (p.second) {
            //printf("new input transfer\n");
            TUdpInTransfer& res = *p.first;
            res.AckTos = ChooseTos(ackTos, DefaultTos.GetAckTos());
            res.NetlibaColor = netlibaColor;
            res.HighPriority = opt.TransferOpt.IsHighPriority();
            res.PacketSize = 0;
            res.HasLastPacket = false;
            res.AttachStats(TotalPendingDataStats);
            res.AttachStats(ColoredPendingDataStats[netlibaColor]);
            res.AttachStats(connection->GetStatsPtr());
        }
        TUdpInTransfer& xfer = *p.first;
        xfer.TimeSinceLastRecv = 0;

        // got duplicate packet
        if (packetId < xfer.GetPacketCount() && xfer.GetPacket(packetId)) {
            xfer.NewPacketsToAck.push_back(packetId);
            return true;
        }

        if (!ReadDataPacket(cmd, &pktData, pktEnd, packetId, &xfer.SharedData, &xfer.PacketSize, opt)) {
            if (opt.TransferOpt.IsSharedMemoryRequired() && xfer.SharedData.Get() && !xfer.SharedData->GetPtr()) {
                SendAckResendNoShmem(S, connection, transfer.Id, DefaultTos.GetAckTos());
            }
            Y_ASSERT(false);
            return false;