Method MaybeSendAddr

src/net_processing.cpp:4501–4566

}

void PeerManagerImpl::MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time)
{
    // Nothing to do for non-address-relay peers
    if (!peer.m_addr_relay_enabled) return;

    LOCK(peer.m_addr_send_times_mutex);
    // Periodically advertise our local address to the peer.
    if (fListen && !m_chainman.ActiveChainstate().IsInitialBlockDownload() &&
        peer.m_next_local_addr_send < current_time) {
        // If we've sent before, clear the bloom filter for the peer, so that our
        // self-announcement will actually go out.
        // This might be unnecessary if the bloom filter has already rolled
        // over since our last self-announcement, but there is only a small
        // bandwidth cost that we can incur by doing this (which happens
        // once a day on average).
        if (peer.m_next_local_addr_send != 0us) {
            peer.m_addr_known->reset();
        }
        if (std::optional<CAddress> local_addr = GetLocalAddrForPeer(&node)) {
            FastRandomContext insecure_rand;
            PushAddress(peer, *local_addr, insecure_rand);
        }
        peer.m_next_local_addr_send = GetExponentialRand(current_time, AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL);
    }

    // We sent an `addr` message to this peer recently. Nothing more to do.
    if (current_time <= peer.m_next_addr_send) return;

    peer.m_next_addr_send = GetExponentialRand(current_time, AVG_ADDRESS_BROADCAST_INTERVAL);

    if (!Assume(peer.m_addrs_to_send.size() <= MAX_ADDR_TO_SEND)) {
        // Should be impossible since we always check size before adding to
        // m_addrs_to_send. Recover by trimming the vector.
        peer.m_addrs_to_send.resize(MAX_ADDR_TO_SEND);
    }

    // Remove addr records that the peer already knows about, and add new
    // addrs to the m_addr_known filter on the same pass.
    auto addr_already_known = [&peer](const CAddress& addr) {
        bool ret = peer.m_addr_known->contains(addr.GetKey());
        if (!ret) peer.m_addr_known->insert(addr.GetKey());
        return ret;
    };
    peer.m_addrs_to_send.erase(std::remove_if(peer.m_addrs_to_send.begin(), peer.m_addrs_to_send.end(), addr_already_known),
                           peer.m_addrs_to_send.end());

    // No addr messages to send
    if (peer.m_addrs_to_send.empty()) return;

    const char* msg_type;
    int make_flags;
    if (peer.m_wants_addrv2) {
        msg_type = NetMsgType::ADDRV2;
        make_flags = ADDRV2_FORMAT;
    } else {
        msg_type = NetMsgType::ADDR;
        make_flags = 0;
    }