How to use

org.apache.flink.queryablestate.network.messages.MessageSerializer

constructor

@Override
public AbstractServerHandler<KvStateInternalRequest, KvStateResponse> initializeHandler() {
  this.serializer = new MessageSerializer<>(
      new KvStateInternalRequest.KvStateInternalRequestDeserializer(),
      new KvStateResponse.KvStateResponseDeserializer());
  return new KvStateServerHandler(this, kvStateRegistry, serializer, stats);
}

  @Override
  public AbstractServerHandler<KvStateRequest, KvStateResponse> initializeHandler() {
    MessageSerializer<KvStateRequest, KvStateResponse> serializer =
        new MessageSerializer<>(
            new KvStateRequest.KvStateRequestDeserializer(),
            new KvStateResponse.KvStateResponseDeserializer());
    return new KvStateClientProxyHandler(this, queryExecutorThreads, serializer, stats);
  }
}

private static Client<KvStateInternalRequest, KvStateResponse> createInternalClient(int threads) {
  final MessageSerializer<KvStateInternalRequest, KvStateResponse> messageSerializer =
      new MessageSerializer<>(
          new KvStateInternalRequest.KvStateInternalRequestDeserializer(),
          new KvStateResponse.KvStateResponseDeserializer());
  return new Client<>(
      "Queryable State Proxy Client",
      threads,
      messageSerializer,
      new DisabledKvStateRequestStats());
}

/**
 * Create the Queryable State Client.
 * @param remoteAddress the {@link InetAddress address} of the {@code Client Proxy} to connect to.
 * @param remotePort the port of the proxy to connect to.
 */
public QueryableStateClient(final InetAddress remoteAddress, final int remotePort) {
  Preconditions.checkArgument(remotePort >= 0 && remotePort <= 65536,
      "Remote Port " + remotePort + " is out of valid port range (0-65536).");
  this.remoteAddress = new InetSocketAddress(remoteAddress, remotePort);
  final MessageSerializer<KvStateRequest, KvStateResponse> messageSerializer =
      new MessageSerializer<>(
          new KvStateRequest.KvStateRequestDeserializer(),
          new KvStateResponse.KvStateResponseDeserializer());
  this.client = new Client<>(
      "Queryable State Client",
      1,
      messageSerializer,
      new DisabledKvStateRequestStats());
}

@Override
public AbstractServerHandler<TestMessage, TestMessage> initializeHandler() {
  return new AbstractServerHandler<TestMessage, TestMessage>(
      this,
      new MessageSerializer<>(new TestMessage.TestMessageDeserializer(), new TestMessage.TestMessageDeserializer()),
      requestStats) {
    @Override
    public CompletableFuture<TestMessage> handleRequest(long requestId, TestMessage request) {
      TestMessage response = new TestMessage(getServerName() + '-' + request.getMessage());
      return CompletableFuture.completedFuture(response);
    }
    @Override
    public CompletableFuture<Void> shutdown() {
      return CompletableFuture.completedFuture(null);
    }
  };
}

    new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
final EmbeddedChannel channel = new EmbeddedChannel(new ClientHandler<>("Test Client", serializer, callback));

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

"Test Client",
1,
new MessageSerializer<>(new TestMessage.TestMessageDeserializer(), new TestMessage.TestMessageDeserializer()),
clientStats

/**
 * Tests that the channel is closed if an Exception reaches the channel handler.
 */
@Test
public void testCloseChannelOnExceptionCaught() throws Exception {
  KvStateRegistry registry = new KvStateRegistry();
  AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();
  MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
  EmbeddedChannel channel = new EmbeddedChannel(handler);
  channel.pipeline().fireExceptionCaught(new RuntimeException("Expected test Exception"));
  ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
  buf.skipBytes(4); // skip frame length
  // Verify the response
  assertEquals(MessageType.SERVER_FAILURE, MessageSerializer.deserializeHeader(buf));
  Throwable response = MessageSerializer.deserializeServerFailure(buf);
  assertTrue(response.getMessage().contains("Expected test Exception"));
  channel.closeFuture().await(READ_TIMEOUT_MILLIS);
  assertFalse(channel.isActive());
}

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

/**
 * Tests response serialization with zero-length serialized result.
 */
@Test
public void testResponseSerializationWithZeroLengthSerializedResult() throws Exception {
  byte[] serializedResult = new byte[0];
  final KvStateResponse response = new KvStateResponse(serializedResult);
  final MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  ByteBuf buf = MessageSerializer.serializeResponse(alloc, 72727278L, response);
  int frameLength = buf.readInt();
  assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
  assertEquals(72727278L, MessageSerializer.getRequestId(buf));
  KvStateResponse responseDeser = serializer.deserializeResponse(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertArrayEquals(serializedResult, responseDeser.getContent());
}

/**
 * Tests response serialization.
 */
@Test
public void testResponseSerialization() throws Exception {
  long requestId = Integer.MAX_VALUE + 72727278L;
  byte[] serializedResult = randomByteArray(1024);
  final KvStateResponse response = new KvStateResponse(serializedResult);
  final MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  ByteBuf buf = MessageSerializer.serializeResponse(alloc, requestId, response);
  int frameLength = buf.readInt();
  assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
  assertEquals(requestId, MessageSerializer.getRequestId(buf));
  KvStateResponse responseDeser = serializer.deserializeResponse(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertArrayEquals(serializedResult, responseDeser.getContent());
}

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

/**
 * Tests request serialization.
 */
@Test
public void testRequestSerialization() throws Exception {
  long requestId = Integer.MAX_VALUE + 1337L;
  KvStateID kvStateId = new KvStateID();
  byte[] serializedKeyAndNamespace = randomByteArray(1024);
  final KvStateInternalRequest request = new KvStateInternalRequest(kvStateId, serializedKeyAndNamespace);
  final MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  ByteBuf buf = MessageSerializer.serializeRequest(alloc, requestId, request);
  int frameLength = buf.readInt();
  assertEquals(MessageType.REQUEST, MessageSerializer.deserializeHeader(buf));
  assertEquals(requestId, MessageSerializer.getRequestId(buf));
  KvStateInternalRequest requestDeser = serializer.deserializeRequest(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertEquals(kvStateId, requestDeser.getKvStateId());
  assertArrayEquals(serializedKeyAndNamespace, requestDeser.getSerializedKeyAndNamespace());
}

/**
 * Tests request serialization with zero-length serialized key and namespace.
 */
@Test
public void testRequestSerializationWithZeroLengthKeyAndNamespace() throws Exception {
  long requestId = Integer.MAX_VALUE + 1337L;
  KvStateID kvStateId = new KvStateID();
  byte[] serializedKeyAndNamespace = new byte[0];
  final KvStateInternalRequest request = new KvStateInternalRequest(kvStateId, serializedKeyAndNamespace);
  final MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  ByteBuf buf = MessageSerializer.serializeRequest(alloc, requestId, request);
  int frameLength = buf.readInt();
  assertEquals(MessageType.REQUEST, MessageSerializer.deserializeHeader(buf));
  assertEquals(requestId, MessageSerializer.getRequestId(buf));
  KvStateInternalRequest requestDeser = serializer.deserializeRequest(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertEquals(kvStateId, requestDeser.getKvStateId());
  assertArrayEquals(serializedKeyAndNamespace, requestDeser.getSerializedKeyAndNamespace());
}

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

/**
 * Tests that incoming buffer instances are recycled.
 */
@Test
public void testIncomingBufferIsRecycled() throws Exception {
  KvStateRegistry registry = new KvStateRegistry();
  AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();
  MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
  EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);
  KvStateInternalRequest request = new KvStateInternalRequest(new KvStateID(), new byte[0]);
  ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), 282872L, request);
  assertEquals(1L, serRequest.refCnt());
  // Write regular request
  channel.writeInbound(serRequest);
  assertEquals("Buffer not recycled", 0L, serRequest.refCnt());
  // Write unexpected msg
  ByteBuf unexpected = channel.alloc().buffer(8);
  unexpected.writeInt(4);
  unexpected.writeInt(4);
  assertEquals(1L, unexpected.refCnt());
  channel.writeInbound(unexpected);
  assertEquals("Buffer not recycled", 0L, unexpected.refCnt());
}

/**
 * Tests the failure response with {@link UnknownKvStateIdException} as cause on
 * queries for unregistered KvStateIDs.
 */
@Test
public void testQueryUnknownKvStateID() throws Exception {
  KvStateRegistry registry = new KvStateRegistry();
  AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();
  MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
      new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());
  KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
  EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);
  long requestId = Integer.MAX_VALUE + 182828L;
  KvStateInternalRequest request = new KvStateInternalRequest(new KvStateID(), new byte[0]);
  ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);
  // Write the request and wait for the response
  channel.writeInbound(serRequest);
  ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
  buf.skipBytes(4); // skip frame length
  // Verify the response
  assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
  RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);
  assertEquals(requestId, response.getRequestId());
  assertTrue("Did not respond with expected failure cause", response.getCause() instanceof UnknownKvStateIdException);
  assertEquals(1L, stats.getNumRequests());
  assertEquals(1L, stats.getNumFailed());
}

new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());