finishResolve() — netty Function Reference

Source Code

resolver-dns/src/main/java/io/netty/resolver/dns/DnsResolveContext.java lines 1081–1140

    private void finishResolve(Promise<List<T>> promise, Throwable cause) {
        // If completeEarly was true we still want to continue processing the queries to ensure we still put everything
        // in the cache eventually.
        if (!completeEarly && !queriesInProgress.isEmpty()) {
            // If there are queries in progress, we should cancel it because we already finished the resolution.
            for (Iterator<Future<AddressedEnvelope<DnsResponse, InetSocketAddress>>> i = queriesInProgress.iterator();
                 i.hasNext();) {
                Future<AddressedEnvelope<DnsResponse, InetSocketAddress>> f = i.next();
                i.remove();

                f.cancel(false);
            }
        }

        if (finalResult != null) {
            if (!promise.isDone()) {
                // Found at least one resolved record.
                final List<T> result = filterResults(finalResult);
                // Lets replace the previous stored result.
                finalResult = Collections.emptyList();
                if (!DnsNameResolver.trySuccess(promise, result)) {
                    for (T item : result) {
                        ReferenceCountUtil.safeRelease(item);
                    }
                }
            } else {
                // This should always be the case as we replaced the list once notify the promise with an empty one
                // and never add to it again.
                assert finalResult.isEmpty();
            }
            return;
        }

        // No resolved address found.
        final int maxAllowedQueries = parent.maxQueriesPerResolve();
        final int tries = maxAllowedQueries - allowedQueries;
        final StringBuilder buf = new StringBuilder(64);

        buf.append("Failed to resolve '").append(hostname).append("' ").append(Arrays.toString(expectedTypes));
        if (tries > 1) {
            if (tries < maxAllowedQueries) {
                buf.append(" after ")
                   .append(tries)
                   .append(" queries ");
            } else {
                buf.append(". Exceeded max queries per resolve ")
                .append(maxAllowedQueries)
                .append(' ');
            }
        }
        final UnknownHostException unknownHostException = new UnknownHostException(buf.toString());
        if (cause == null) {
            // Only cache if the failure was not because of an IO error / timeout that was caused by the query
            // itself.
            cache(hostname, additionals, unknownHostException);
        } else {
            unknownHostException.initCause(cause);
        }
        promise.tryFailure(unknownHostException);
    }