DnsAddressResolveContext Class — netty Architecture

Source Code

resolver-dns/src/main/java/io/netty/resolver/dns/DnsAddressResolveContext.java lines 31–113

final class DnsAddressResolveContext extends DnsResolveContext<InetAddress> {

    private final DnsCache resolveCache;
    private final AuthoritativeDnsServerCache authoritativeDnsServerCache;
    private final boolean completeEarlyIfPossible;

    DnsAddressResolveContext(DnsNameResolver parent, Channel channel,
                             Promise<?> originalPromise, String hostname, DnsRecord[] additionals,
                             DnsServerAddressStream nameServerAddrs, int allowedQueries, DnsCache resolveCache,
                             AuthoritativeDnsServerCache authoritativeDnsServerCache,
                             boolean completeEarlyIfPossible) {
        super(parent, channel, originalPromise, hostname, DnsRecord.CLASS_IN,
              parent.resolveRecordTypes(), additionals, nameServerAddrs, allowedQueries);
        this.resolveCache = resolveCache;
        this.authoritativeDnsServerCache = authoritativeDnsServerCache;
        this.completeEarlyIfPossible = completeEarlyIfPossible;
    }

    @Override
    DnsResolveContext<InetAddress> newResolverContext(DnsNameResolver parent, Channel channel,
                                                      Promise<?> originalPromise,
                                                      String hostname,
                                                      int dnsClass, DnsRecordType[] expectedTypes,
                                                      DnsRecord[] additionals,
                                                      DnsServerAddressStream nameServerAddrs, int allowedQueries) {
        return new DnsAddressResolveContext(parent, channel, originalPromise, hostname, additionals,
                nameServerAddrs, allowedQueries, resolveCache, authoritativeDnsServerCache, completeEarlyIfPossible);
    }

    @Override
    InetAddress convertRecord(DnsRecord record, String hostname, DnsRecord[] additionals, EventLoop eventLoop) {
        return decodeAddress(record, hostname, parent.isDecodeIdn());
    }

    @Override
    List<InetAddress> filterResults(List<InetAddress> unfiltered) {
        Collections.sort(unfiltered, PreferredAddressTypeComparator.comparator(parent.preferredAddressType()));
        return unfiltered;
    }

    @Override
    boolean isCompleteEarly(InetAddress resolved) {
        return completeEarlyIfPossible &&
                DnsNameResolver.addressType(parent.preferredAddressType()) == resolved.getClass();
    }

    @Override
    boolean isDuplicateAllowed() {
        // We don't want include duplicates to mimic JDK behaviour.
        return false;
    }

    @Override
    void cache(String hostname, DnsRecord[] additionals,
               DnsRecord result, InetAddress convertedResult) {
        resolveCache.cache(hostname, additionals, convertedResult, result.timeToLive(),
                channel().eventLoop());
    }

    @Override
    void cache(String hostname, DnsRecord[] additionals, UnknownHostException cause) {
        resolveCache.cache(hostname, additionals, cause, channel().eventLoop());
    }

    @Override
    void doSearchDomainQuery(String hostname, Promise<List<InetAddress>> nextPromise) {
        // Query the cache for the hostname first and only do a query if we could not find it in the cache.
        if (!DnsNameResolver.doResolveAllCached(hostname, additionals, nextPromise, resolveCache,
                parent.searchDomains(), parent.ndots(), parent.resolvedInternetProtocolFamiliesUnsafe())) {
            super.doSearchDomainQuery(hostname, nextPromise);
        }
    }

    @Override
    DnsCache resolveCache() {
        return resolveCache;
    }

    @Override
    AuthoritativeDnsServerCache authoritativeDnsServerCache() {
        return authoritativeDnsServerCache;