How to use

Serializers

in

org.apache.flink.api.java.typeutils.runtime.kryo

private static void recursivelyRegisterGenericType(Type fieldType, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (fieldType instanceof ParameterizedType) {
    // field has generics
    ParameterizedType parameterizedFieldType = (ParameterizedType) fieldType;
    
    for (Type t: parameterizedFieldType.getActualTypeArguments()) {
      if (TypeExtractionUtils.isClassType(t) ) {
        recursivelyRegisterType(TypeExtractionUtils.typeToClass(t), config, alreadySeen);
      }
    }
    recursivelyRegisterGenericType(parameterizedFieldType.getRawType(), config, alreadySeen);
  }
  else if (fieldType instanceof GenericArrayType) {
    GenericArrayType genericArrayType = (GenericArrayType) fieldType;
    recursivelyRegisterGenericType(genericArrayType.getGenericComponentType(), config, alreadySeen);
  }
  else if (fieldType instanceof Class) {
    Class<?> clazz = (Class<?>) fieldType;
    recursivelyRegisterType(clazz, config, alreadySeen);
  }
}

public static void recursivelyRegisterType(TypeInformation<?> typeInfo, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (typeInfo instanceof GenericTypeInfo) {
    GenericTypeInfo<?> genericTypeInfo = (GenericTypeInfo<?>) typeInfo;
    Serializers.recursivelyRegisterType(genericTypeInfo.getTypeClass(), config, alreadySeen);
  }
  else if (typeInfo instanceof CompositeType) {
    List<GenericTypeInfo<?>> genericTypesInComposite = new ArrayList<>();
    getContainedGenericTypes((CompositeType<?>)typeInfo, genericTypesInComposite);
    for (GenericTypeInfo<?> gt : genericTypesInComposite) {
      Serializers.recursivelyRegisterType(gt.getTypeClass(), config, alreadySeen);
    }
  }
  else if (typeInfo instanceof ObjectArrayTypeInfo) {
    ObjectArrayTypeInfo<?, ?> objectArrayTypeInfo = (ObjectArrayTypeInfo<?, ?>) typeInfo;
    recursivelyRegisterType(objectArrayTypeInfo.getComponentInfo(), config, alreadySeen);
  }
}

assertEquals(GenericTypeInfo.class, te.getClass());
Serializers.recursivelyRegisterType(te.getTypeClass(), ec, new HashSet<>());

/**
 * Returns all GenericTypeInfos contained in a composite type.
 *
 * @param typeInfo {@link CompositeType}
 */
private static void getContainedGenericTypes(CompositeType<?> typeInfo, List<GenericTypeInfo<?>> target) {
  for (int i = 0; i < typeInfo.getArity(); i++) {
    TypeInformation<?> type = typeInfo.getTypeAt(i);
    if (type instanceof CompositeType) {
      getContainedGenericTypes((CompositeType<?>) type, target);
    } else if (type instanceof GenericTypeInfo) {
      if (!target.contains(type)) {
        target.add((GenericTypeInfo<?>) type);
      }
    }
  }
}

@Test
public void testTypeRegistration() {
  ExecutionConfig conf = new ExecutionConfig();
  Serializers.recursivelyRegisterType(ClassWithNested.class, conf, new HashSet<Class<?>>());
  
  KryoSerializer<String> kryo = new KryoSerializer<>(String.class, conf); // we create Kryo from another type.
  Assert.assertTrue(kryo.getKryo().getRegistration(FromNested.class).getId() > 0);
  Assert.assertTrue(kryo.getKryo().getRegistration(ClassWithNested.class).getId() > 0);
  Assert.assertTrue(kryo.getKryo().getRegistration(Path.class).getId() > 0);
  
  // check if the generic type from one field is also registered (its very likely that
  // generic types are also used as fields somewhere.
  Assert.assertTrue(kryo.getKryo().getRegistration(FromGeneric1.class).getId() > 0);
  Assert.assertTrue(kryo.getKryo().getRegistration(FromGeneric2.class).getId() > 0);
  Assert.assertTrue(kryo.getKryo().getRegistration(Node.class).getId() > 0);
  
  
  // register again and make sure classes are still registered
  ExecutionConfig conf2 = new ExecutionConfig();
  Serializers.recursivelyRegisterType(ClassWithNested.class, conf2, new HashSet<Class<?>>());
  KryoSerializer<String> kryo2 = new KryoSerializer<>(String.class, conf);
  assertTrue(kryo2.getKryo().getRegistration(FromNested.class).getId() > 0);
}

/**
 * Returns all GenericTypeInfos contained in a composite type.
 *
 * @param typeInfo {@link CompositeType}
 */
private static void getContainedGenericTypes(CompositeType<?> typeInfo, List<GenericTypeInfo<?>> target) {
  for (int i = 0; i < typeInfo.getArity(); i++) {
    TypeInformation<?> type = typeInfo.getTypeAt(i);
    if (type instanceof CompositeType) {
      getContainedGenericTypes((CompositeType<?>) type, target);
    } else if (type instanceof GenericTypeInfo) {
      if (!target.contains(type)) {
        target.add((GenericTypeInfo<?>) type);
      }
    }
  }
}

public static void recursivelyRegisterType(Class<?> type, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  // don't register or remember primitives
  if (type == null || type.isPrimitive() || type == Object.class) {
    return;
  }
  
  // prevent infinite recursion for recursive types
  if (!alreadySeen.add(type)) {
    return;
  }
  
  if (type.isArray()) {
    recursivelyRegisterType(type.getComponentType(), config, alreadySeen);
  }
  else {
    config.registerKryoType(type);
    // add serializers for Avro type if necessary
    AvroUtils.getAvroUtils().addAvroSerializersIfRequired(config, type);
    Field[] fields = type.getDeclaredFields();
    for (Field field : fields) {
      if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())) {
        continue;
      }
      Type fieldType = field.getGenericType();
      recursivelyRegisterGenericType(fieldType, config, alreadySeen);
    }
  }
}

public static void recursivelyRegisterType(TypeInformation<?> typeInfo, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (typeInfo instanceof GenericTypeInfo) {
    GenericTypeInfo<?> genericTypeInfo = (GenericTypeInfo<?>) typeInfo;
    Serializers.recursivelyRegisterType(genericTypeInfo.getTypeClass(), config, alreadySeen);
  }
  else if (typeInfo instanceof CompositeType) {
    List<GenericTypeInfo<?>> genericTypesInComposite = new ArrayList<>();
    getContainedGenericTypes((CompositeType<?>)typeInfo, genericTypesInComposite);
    for (GenericTypeInfo<?> gt : genericTypesInComposite) {
      Serializers.recursivelyRegisterType(gt.getTypeClass(), config, alreadySeen);
    }
  }
  else if (typeInfo instanceof ObjectArrayTypeInfo) {
    ObjectArrayTypeInfo<?, ?> objectArrayTypeInfo = (ObjectArrayTypeInfo<?, ?>) typeInfo;
    recursivelyRegisterType(objectArrayTypeInfo.getComponentInfo(), config, alreadySeen);
  }
}

  @Test
  public void testTypeRegistrationFromTypeInfo() {
    ExecutionConfig conf = new ExecutionConfig();
    Serializers.recursivelyRegisterType(new GenericTypeInfo<>(ClassWithNested.class), conf, new HashSet<Class<?>>());

    KryoSerializer<String> kryo = new KryoSerializer<>(String.class, conf); // we create Kryo from another type.

    assertTrue(kryo.getKryo().getRegistration(FromNested.class).getId() > 0);
    assertTrue(kryo.getKryo().getRegistration(ClassWithNested.class).getId() > 0);
    assertTrue(kryo.getKryo().getRegistration(Path.class).getId() > 0);

    // check if the generic type from one field is also registered (its very likely that
    // generic types are also used as fields somewhere.
    assertTrue(kryo.getKryo().getRegistration(FromGeneric1.class).getId() > 0);
    assertTrue(kryo.getKryo().getRegistration(FromGeneric2.class).getId() > 0);
    assertTrue(kryo.getKryo().getRegistration(Node.class).getId() > 0);
  }
}

/**
 * Returns all GenericTypeInfos contained in a composite type.
 *
 * @param typeInfo {@link CompositeType}
 */
private static void getContainedGenericTypes(CompositeType<?> typeInfo, List<GenericTypeInfo<?>> target) {
  for (int i = 0; i < typeInfo.getArity(); i++) {
    TypeInformation<?> type = typeInfo.getTypeAt(i);
    if (type instanceof CompositeType) {
      getContainedGenericTypes((CompositeType<?>) type, target);
    } else if (type instanceof GenericTypeInfo) {
      if (!target.contains(type)) {
        target.add((GenericTypeInfo<?>) type);
      }
    }
  }
}

private static void recursivelyRegisterGenericType(Type fieldType, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (fieldType instanceof ParameterizedType) {
    // field has generics
    ParameterizedType parameterizedFieldType = (ParameterizedType) fieldType;
    
    for (Type t: parameterizedFieldType.getActualTypeArguments()) {
      if (TypeExtractionUtils.isClassType(t) ) {
        recursivelyRegisterType(TypeExtractionUtils.typeToClass(t), config, alreadySeen);
      }
    }
    recursivelyRegisterGenericType(parameterizedFieldType.getRawType(), config, alreadySeen);
  }
  else if (fieldType instanceof GenericArrayType) {
    GenericArrayType genericArrayType = (GenericArrayType) fieldType;
    recursivelyRegisterGenericType(genericArrayType.getGenericComponentType(), config, alreadySeen);
  }
  else if (fieldType instanceof Class) {
    Class<?> clazz = (Class<?>) fieldType;
    recursivelyRegisterType(clazz, config, alreadySeen);
  }
}

public static void recursivelyRegisterType(TypeInformation<?> typeInfo, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (typeInfo instanceof GenericTypeInfo) {
    GenericTypeInfo<?> genericTypeInfo = (GenericTypeInfo<?>) typeInfo;
    Serializers.recursivelyRegisterType(genericTypeInfo.getTypeClass(), config, alreadySeen);
  }
  else if (typeInfo instanceof CompositeType) {
    List<GenericTypeInfo<?>> genericTypesInComposite = new ArrayList<>();
    getContainedGenericTypes((CompositeType<?>)typeInfo, genericTypesInComposite);
    for (GenericTypeInfo<?> gt : genericTypesInComposite) {
      Serializers.recursivelyRegisterType(gt.getTypeClass(), config, alreadySeen);
    }
  }
  else if (typeInfo instanceof ObjectArrayTypeInfo) {
    ObjectArrayTypeInfo<?, ?> objectArrayTypeInfo = (ObjectArrayTypeInfo<?, ?>) typeInfo;
    recursivelyRegisterType(objectArrayTypeInfo.getComponentInfo(), config, alreadySeen);
  }
}

private static void recursivelyRegisterGenericType(Type fieldType, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  if (fieldType instanceof ParameterizedType) {
    // field has generics
    ParameterizedType parameterizedFieldType = (ParameterizedType) fieldType;
    
    for (Type t: parameterizedFieldType.getActualTypeArguments()) {
      if (TypeExtractionUtils.isClassType(t) ) {
        recursivelyRegisterType(TypeExtractionUtils.typeToClass(t), config, alreadySeen);
      }
    }
    recursivelyRegisterGenericType(parameterizedFieldType.getRawType(), config, alreadySeen);
  }
  else if (fieldType instanceof GenericArrayType) {
    GenericArrayType genericArrayType = (GenericArrayType) fieldType;
    recursivelyRegisterGenericType(genericArrayType.getGenericComponentType(), config, alreadySeen);
  }
  else if (fieldType instanceof Class) {
    Class<?> clazz = (Class<?>) fieldType;
    recursivelyRegisterType(clazz, config, alreadySeen);
  }
}

public static void recursivelyRegisterType(Class<?> type, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  // don't register or remember primitives
  if (type == null || type.isPrimitive() || type == Object.class) {
    return;
  }
  
  // prevent infinite recursion for recursive types
  if (!alreadySeen.add(type)) {
    return;
  }
  
  if (type.isArray()) {
    recursivelyRegisterType(type.getComponentType(), config, alreadySeen);
  }
  else {
    config.registerKryoType(type);
    // add serializers for Avro type if necessary
    AvroUtils.getAvroUtils().addAvroSerializersIfRequired(config, type);
    Field[] fields = type.getDeclaredFields();
    for (Field field : fields) {
      if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())) {
        continue;
      }
      Type fieldType = field.getGenericType();
      recursivelyRegisterGenericType(fieldType, config, alreadySeen);
    }
  }
}

public static void recursivelyRegisterType(Class<?> type, ExecutionConfig config, Set<Class<?>> alreadySeen) {
  // don't register or remember primitives
  if (type == null || type.isPrimitive() || type == Object.class) {
    return;
  }
  
  // prevent infinite recursion for recursive types
  if (!alreadySeen.add(type)) {
    return;
  }
  
  if (type.isArray()) {
    recursivelyRegisterType(type.getComponentType(), config, alreadySeen);
  }
  else {
    config.registerKryoType(type);
    // add serializers for Avro type if necessary
    AvroUtils.getAvroUtils().addAvroSerializersIfRequired(config, type);
    Field[] fields = type.getDeclaredFields();
    for (Field field : fields) {
      if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())) {
        continue;
      }
      Type fieldType = field.getGenericType();
      recursivelyRegisterGenericType(fieldType, config, alreadySeen);
    }
  }
}