DnsServerAddressStream() — netty Function Reference

Source Code

resolver-dns-classes-macos/src/main/java/io/netty/resolver/dns/macos/MacOSDnsServerAddressStreamProvider.java lines 168–199

    @Override
    public DnsServerAddressStream nameServerAddressStream(String hostname) {
        long last = lastRefresh.get();
        Map<String, DnsServerAddresses> resolverMap = currentMappings;
        if (System.nanoTime() - last > REFRESH_INTERVAL) {
            // This is slightly racy which means it will be possible still use the old configuration for a small
            // amount of time, but that's ok.
            if (lastRefresh.compareAndSet(last, System.nanoTime())) {
                resolverMap = currentMappings = retrieveCurrentMappings();
            }
        }

        final String originalHostname = hostname;
        for (;;) {
            int i = hostname.indexOf('.', 1);
            if (i < 0 || i == hostname.length() - 1) {
                // Try access default mapping.
                DnsServerAddresses addresses = resolverMap.get(StringUtil.EMPTY_STRING);
                if (addresses != null) {
                    return addresses.stream();
                }
                return DnsServerAddressStreamProviders.unixDefault().nameServerAddressStream(originalHostname);
            }

            DnsServerAddresses addresses = resolverMap.get(hostname);
            if (addresses != null) {
                return addresses.stream();
            }

            hostname = hostname.substring(i + 1);
        }
    }