org.apache.flink.api.common.typeutils

Class CompatibilityUtil

java.lang.Object

org.apache.flink.api.common.typeutils.CompatibilityUtil

@Internal
public class CompatibilityUtil
extends Object

Utilities related to serializer compatibility.

Constructor Summary

Constructors

Constructor and Description
CompatibilityUtil()

Method Summary

Modifier and Type

Method and Description

static <T> CompatibilityResult<T>

resolveCompatibilityResult(TypeSerializer<?> precedingSerializer, Class<?> dummySerializerClassTag, TypeSerializerConfigSnapshot precedingSerializerConfigSnapshot, TypeSerializer<T> newSerializer) Resolves the final compatibility result of two serializers by taking into account compound information, including the preceding serializer, the preceding serializer's configuration snapshot, and the new serializer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CompatibilityUtil

public CompatibilityUtil()

Method Detail

resolveCompatibilityResult

public static <T> CompatibilityResult<T> resolveCompatibilityResult(@Nullable
                                                                    TypeSerializer<?> precedingSerializer,
                                                                    Class<?> dummySerializerClassTag,
                                                                    TypeSerializerConfigSnapshot precedingSerializerConfigSnapshot,
                                                                    TypeSerializer<T> newSerializer)

Resolves the final compatibility result of two serializers by taking into account compound information, including the preceding serializer, the preceding serializer's configuration snapshot, and the new serializer. This method has the side effect that the provided new serializer may have been reconfigured in order to remain compatible. The final result is determined as follows: 1. If there is no configuration snapshot of the preceding serializer, assumes the new serializer to be compatible. 2. Confront the configuration snapshot with the new serializer. 3. If the result is compatible, just return that as the result. 4. If not compatible and requires migration, check if the preceding serializer is valid. If yes, use that as the convert deserializer for state migration. 5. If the preceding serializer is not valid, check if the result came with a convert deserializer. If yes, use that for state migration and simply return the result. 6. If all of above fails, state migration is required but could not be performed; throw exception.

Type Parameters:

T - Type of the data handled by the serializers

Parameters:

precedingSerializer - the preceding serializer used to write the data, null if none could be retrieved

dummySerializerClassTag - any class tags that identifies the preceding serializer as a dummy placeholder

precedingSerializerConfigSnapshot - configuration snapshot of the preceding serializer

newSerializer - the new serializer to ensure compatibility with

Returns:

the final resolved compatibility result