extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/KafkaSeekableStreamEndSequenceNumbersTest.java

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 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing,
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 * specific language governing permissions and limitations
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package org.apache.druid.indexing.kafka;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.exc.InvalidTypeIdException;
import com.google.common.collect.ImmutableMap;
import com.google.inject.Injector;
import com.google.inject.name.Names;
import org.apache.druid.data.input.kafka.KafkaTopicPartition;
import org.apache.druid.guice.StartupInjectorBuilder;
import org.apache.druid.indexing.seekablestream.SeekableStreamEndSequenceNumbers;
import org.apache.druid.initialization.CoreInjectorBuilder;
import org.apache.druid.initialization.DruidModule;
import org.apache.druid.java.util.common.jackson.JacksonUtils;
import org.junit.Assert;
import org.junit.Test;

import java.util.Map;

public class KafkaSeekableStreamEndSequenceNumbersTest
{

  private static final ObjectMapper OBJECT_MAPPER = createObjectMapper();

  @Test
  public void testSerde() throws Exception
  {
    final String stream = "theStream";
    final Map<KafkaTopicPartition, Long> offsetMap = ImmutableMap.of(
        new KafkaTopicPartition(false, null, 1), 2L,
        new KafkaTopicPartition(false, null, 3), 4L
    );

    final KafkaSeekableStreamEndSequenceNumbers partitions = new KafkaSeekableStreamEndSequenceNumbers(
        stream,
        null,
        offsetMap,
        null
    );
    final String serializedString = OBJECT_MAPPER.writeValueAsString(partitions);

    // Check round-trip.
    final SeekableStreamEndSequenceNumbers<KafkaTopicPartition, Long> partitions2 = OBJECT_MAPPER.readValue(
        serializedString,
        new TypeReference<SeekableStreamEndSequenceNumbers<KafkaTopicPartition, Long>>() {}
    );

    Assert.assertEquals(
        "Round trip",
        partitions,
        new KafkaSeekableStreamEndSequenceNumbers(partitions2.getStream(),
            partitions2.getTopic(),
            partitions2.getPartitionSequenceNumberMap(),
            partitions2.getPartitionOffsetMap()
        )
    );

    // Check backwards compatibility.
    final Map<String, Object> asMap = OBJECT_MAPPER.readValue(
        serializedString,
        JacksonUtils.TYPE_REFERENCE_MAP_STRING_OBJECT
    );

    Assert.assertEquals(stream, asMap.get("stream"));
    Assert.assertEquals(stream, asMap.get("topic"));

    // Jackson will deserialize the maps as string -> int maps, not int -> long.
    Assert.assertEquals(
        offsetMap,
        OBJECT_MAPPER.convertValue(asMap.get("partitionSequenceNumberMap"), new TypeReference<Map<KafkaTopicPartition, Long>>() {})
    );
    Assert.assertEquals(
        offsetMap,
        OBJECT_MAPPER.convertValue(asMap.get("partitionOffsetMap"), new TypeReference<Map<KafkaTopicPartition, Long>>() {})
    );

    // check that KafkaSeekableStreamEndSequenceNumbers not registered with mapper, so no possible collision
    // when deserializing it from String / bytes
    boolean expectedExceptionThrown = false;
    try {
      OBJECT_MAPPER.readValue(
          serializedString,
          KafkaSeekableStreamEndSequenceNumbers.class
      );
    }
    catch (InvalidTypeIdException e) {
      expectedExceptionThrown = true;
    }

    Assert.assertTrue("KafkaSeekableStreamEndSequenceNumbers should not be registered type", expectedExceptionThrown);
  }

  private static ObjectMapper createObjectMapper()
  {
    DruidModule module = new KafkaIndexTaskModule();
    final Injector injector = new CoreInjectorBuilder(new StartupInjectorBuilder().build())
        .addModule(
            binder -> {
              binder.bindConstant().annotatedWith(Names.named("serviceName")).to("test");
              binder.bindConstant().annotatedWith(Names.named("servicePort")).to(8000);
              binder.bindConstant().annotatedWith(Names.named("tlsServicePort")).to(9000);
            }
        )
        .build();

    ObjectMapper objectMapper = injector.getInstance(ObjectMapper.class);
    module.getJacksonModules().forEach(objectMapper::registerModule);
    return objectMapper;
  }
}