How to use

deserializeHeader

method

in

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

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
  try {
    ByteBuf buf = (ByteBuf) msg;
    MessageType msgType = MessageSerializer.deserializeHeader(buf);
    if (msgType == MessageType.REQUEST_RESULT) {
      long requestId = MessageSerializer.getRequestId(buf);
      RESP result = serializer.deserializeResponse(buf);
      callback.onRequestResult(requestId, result);
    } else if (msgType == MessageType.REQUEST_FAILURE) {
      RequestFailure failure = MessageSerializer.deserializeRequestFailure(buf);
      callback.onRequestFailure(failure.getRequestId(), failure.getCause());
    } else if (msgType == MessageType.SERVER_FAILURE) {
      throw MessageSerializer.deserializeServerFailure(buf);
    } else {
      throw new IllegalStateException("Unexpected response type '" + msgType + "'");
    }
  } catch (Throwable t1) {
    try {
      callback.onFailure(t1);
    } catch (Throwable t2) {
      LOG.error("Failed to notify callback about failure", t2);
    }
  } finally {
    ReferenceCountUtil.release(msg);
  }
}

/**
 * Tests server failure serialization.
 */
@Test
public void testServerFailureSerialization() throws Exception {
  IllegalStateException cause = new IllegalStateException("Expected test");
  ByteBuf buf = MessageSerializer.serializeServerFailure(alloc, cause);
  int frameLength = buf.readInt();
  assertEquals(MessageType.SERVER_FAILURE, MessageSerializer.deserializeHeader(buf));
  Throwable request = MessageSerializer.deserializeServerFailure(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertEquals(cause.getClass(), request.getClass());
  assertEquals(cause.getMessage(), request.getMessage());
}

final MessageType msgType = MessageSerializer.deserializeHeader(buf);

/**
 * Tests request failure serialization.
 */
@Test
public void testKvStateRequestFailureSerialization() throws Exception {
  long requestId = Integer.MAX_VALUE + 1111222L;
  IllegalStateException cause = new IllegalStateException("Expected test");
  ByteBuf buf = MessageSerializer.serializeRequestFailure(alloc, requestId, cause);
  int frameLength = buf.readInt();
  assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
  RequestFailure requestFailure = MessageSerializer.deserializeRequestFailure(buf);
  assertEquals(buf.readerIndex(), frameLength + 4);
  assertEquals(requestId, requestFailure.getRequestId());
  assertEquals(cause.getClass(), requestFailure.getCause().getClass());
  assertEquals(cause.getMessage(), requestFailure.getCause().getMessage());
}

  @Override
  public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
    ByteBuf buf = (ByteBuf) msg;
    assertEquals(MessageType.REQUEST, MessageSerializer.deserializeHeader(buf));
    long requestId = MessageSerializer.getRequestId(buf);
    KvStateInternalRequest request = serializer.deserializeRequest(buf);
    buf.release();
    KvStateResponse response = new KvStateResponse(serializedResult);
    ByteBuf serResponse = MessageSerializer.serializeResponse(
        ctx.alloc(),
        requestId,
        response);
    ctx.channel().writeAndFlush(serResponse);
  }
});

/**
 * 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());
}

assertNotNull("Channel not active", ch);
assertEquals(MessageType.REQUEST, MessageSerializer.deserializeHeader(buf));
long requestId = MessageSerializer.getRequestId(buf);
KvStateInternalRequest deserRequest = serializer.deserializeRequest(buf);

assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

assertEquals(MessageType.SERVER_FAILURE, MessageSerializer.deserializeHeader(buf));
Throwable response = MessageSerializer.deserializeServerFailure(buf);
assertEquals(MessageType.SERVER_FAILURE, MessageSerializer.deserializeHeader(buf));
response = MessageSerializer.deserializeServerFailure(buf);

assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
assertEquals(requestId, MessageSerializer.getRequestId(buf));
KvStateResponse response = server.getSerializer().deserializeResponse(buf);

/**
 * 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());
}

assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);
assertEquals(182828L, response.getRequestId());
assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
response = MessageSerializer.deserializeRequestFailure(buf);
assertEquals(182829L, response.getRequestId());

assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
long deserRequestId = MessageSerializer.getRequestId(buf);
KvStateResponse response = serializer.deserializeResponse(buf);

/**
 * 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());
}

/**
 * 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 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());
}

assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
  try {
    ByteBuf buf = (ByteBuf) msg;
    MessageType msgType = MessageSerializer.deserializeHeader(buf);
    if (msgType == MessageType.REQUEST_RESULT) {
      long requestId = MessageSerializer.getRequestId(buf);
      RESP result = serializer.deserializeResponse(buf);
      callback.onRequestResult(requestId, result);
    } else if (msgType == MessageType.REQUEST_FAILURE) {
      RequestFailure failure = MessageSerializer.deserializeRequestFailure(buf);
      callback.onRequestFailure(failure.getRequestId(), failure.getCause());
    } else if (msgType == MessageType.SERVER_FAILURE) {
      throw MessageSerializer.deserializeServerFailure(buf);
    } else {
      throw new IllegalStateException("Unexpected response type '" + msgType + "'");
    }
  } catch (Throwable t1) {
    try {
      callback.onFailure(t1);
    } catch (Throwable t2) {
      LOG.error("Failed to notify callback about failure", t2);
    }
  } finally {
    ReferenceCountUtil.release(msg);
  }
}