testCNameCached() — netty Function Reference

Architecture documentation for the testCNameCached() function in DnsNameResolverTest.java from the netty codebase.

Function java Buffer Telemetry calls 3

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Buffer→ Telemetry→ testCNameCached() — netty Function Reference

Dependency Diagram

graph TD
  96b415a8_680a_71b7_4900_29d1fe02c25e["testCNameCached()"]
  b6215f36_0afe_a284_a3fd_3999e90a8e97["DnsNameResolverTest"]
  96b415a8_680a_71b7_4900_29d1fe02c25e -->|defined in| b6215f36_0afe_a284_a3fd_3999e90a8e97
  f68a278a_d1e5_7598_a2d3_c261c81029bc["get()"]
  96b415a8_680a_71b7_4900_29d1fe02c25e -->|calls| f68a278a_d1e5_7598_a2d3_c261c81029bc
  320a7bb7_1770_5812_3b9d_752bd44edf24["cache()"]
  96b415a8_680a_71b7_4900_29d1fe02c25e -->|calls| 320a7bb7_1770_5812_3b9d_752bd44edf24
  e0db6033_0923_3a43_22a1_11714277de6c["clear()"]
  96b415a8_680a_71b7_4900_29d1fe02c25e -->|calls| e0db6033_0923_3a43_22a1_11714277de6c
  style 96b415a8_680a_71b7_4900_29d1fe02c25e fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

resolver-dns/src/test/java/io/netty/resolver/dns/DnsNameResolverTest.java lines 2885–2999

    @ParameterizedTest
    @EnumSource(DnsNameResolverChannelStrategy.class)
    public void testCNameCached(DnsNameResolverChannelStrategy strategy) throws Exception {
        final Map<String, String> cache = new ConcurrentHashMap<String, String>();
        final AtomicInteger cnameQueries = new AtomicInteger();
        final AtomicInteger aQueries = new AtomicInteger();

        TestDnsServer dnsServer2 = new TestDnsServer(new RecordStore() {

            @Override
            public Set<ResourceRecord> getRecords(QuestionRecord question) {
                if ("cname.netty.io".equals(question.getDomainName())) {
                    aQueries.incrementAndGet();

                    return Collections.<ResourceRecord>singleton(new TestDnsServer.TestResourceRecord(
                            question.getDomainName(), RecordType.A,
                            Collections.<String, Object>singletonMap(
                                    DnsAttribute.IP_ADDRESS.toLowerCase(), "10.0.0.99")));
                }
                if ("x.netty.io".equals(question.getDomainName())) {
                    cnameQueries.incrementAndGet();

                    return Collections.<ResourceRecord>singleton(new TestDnsServer.TestResourceRecord(
                            question.getDomainName(), RecordType.CNAME,
                            Collections.<String, Object>singletonMap(
                                    DnsAttribute.DOMAIN_NAME.toLowerCase(), "cname.netty.io")));
                }
                if ("y.netty.io".equals(question.getDomainName())) {
                    cnameQueries.incrementAndGet();

                    return Collections.<ResourceRecord>singleton(new TestDnsServer.TestResourceRecord(
                            question.getDomainName(), RecordType.CNAME,
                            Collections.<String, Object>singletonMap(
                                    DnsAttribute.DOMAIN_NAME.toLowerCase(), "x.netty.io")));
                }
                return Collections.emptySet();
            }
        });
        dnsServer2.start();
        DnsNameResolver resolver = null;
        try {
            DnsNameResolverBuilder builder = newResolver(strategy)
                    .recursionDesired(true)
                    .resolvedAddressTypes(ResolvedAddressTypes.IPV4_ONLY)
                    .maxQueriesPerResolve(16)
                    .nameServerProvider(new SingletonDnsServerAddressStreamProvider(dnsServer2.localAddress()))
                    .resolveCache(NoopDnsCache.INSTANCE)
                    .cnameCache(new DnsCnameCache() {
                        @Override
                        public String get(String hostname) {
                            assertTrue(hostname.endsWith("."), hostname);
                            return cache.get(hostname);
                        }

                        @Override
                        public void cache(String hostname, String cname, long originalTtl, EventLoop loop) {
                            assertTrue(hostname.endsWith("."), hostname);
                            cache.put(hostname, cname);
                        }

                        @Override
                        public void clear() {
                            // NOOP
                        }

                        @Override
                        public boolean clear(String hostname) {
                            return false;
                        }
                    });
            resolver = builder.build();
            List<InetAddress> resolvedAddresses =
                    resolver.resolveAll("x.netty.io").syncUninterruptibly().getNow();
            assertEquals(1, resolvedAddresses.size());
            assertTrue(resolvedAddresses.contains(InetAddress.getByAddress(new byte[] { 10, 0, 0, 99 })));

            assertEquals("cname.netty.io.", cache.get("x.netty.io."));
            assertEquals(1, cnameQueries.get());
            assertEquals(1, aQueries.get());

            resolvedAddresses =