AuthoritativeDnsServerCacheAdapter Class — netty Architecture

Source Code

resolver-dns/src/main/java/io/netty/resolver/dns/AuthoritativeDnsServerCacheAdapter.java lines 32–78

final class AuthoritativeDnsServerCacheAdapter implements AuthoritativeDnsServerCache {

    private static final DnsRecord[] EMPTY = new DnsRecord[0];
    private final DnsCache cache;

    AuthoritativeDnsServerCacheAdapter(DnsCache cache) {
        this.cache = checkNotNull(cache, "cache");
    }

    @Override
    public DnsServerAddressStream get(String hostname) {
        List<? extends DnsCacheEntry> entries = cache.get(hostname, EMPTY);
        if (entries == null || entries.isEmpty()) {
            return null;
        }
        if (entries.get(0).cause() != null) {
            return null;
        }

        List<InetSocketAddress> addresses = new ArrayList<InetSocketAddress>(entries.size());

        int i = 0;
        do {
            InetAddress addr = entries.get(i).address();
            addresses.add(new InetSocketAddress(addr, DefaultDnsServerAddressStreamProvider.DNS_PORT));
        } while (++i < entries.size());
        return new SequentialDnsServerAddressStream(addresses, 0);
    }

    @Override
    public void cache(String hostname, InetSocketAddress address, long originalTtl, EventLoop loop) {
        // We only cache resolved addresses.
        if (!address.isUnresolved()) {
            cache.cache(hostname, EMPTY, address.getAddress(), originalTtl, loop);
        }
    }

    @Override
    public void clear() {
        cache.clear();
    }

    @Override
    public boolean clear(String hostname) {
        return cache.clear(hostname);
    }
}