Class CompatibleFieldSerializer<T>

All Implemented Interfaces:
Comparator<FieldSerializer.CachedField>

public class CompatibleFieldSerializer<T> extends FieldSerializer<T,FieldSerializerConfig>
Serializes objects using direct field assignment, providing both forward and backward compatibility. This means fields can be added or removed without invalidating previously serialized bytes. Changing the type of a field is not supported. Like FieldSerializer, it can serialize most classes without needing annotations. The forward and backward compatibility comes at a cost: the first time the class is encountered in the serialized bytes, a simple schema is written containing the field name strings. Also, during serialization and deserialization buffers are allocated to perform chunked encoding. This is what enables CompatibleFieldSerializer to skip bytes for fields it does not know about.

Removing fields when references are enabled can cause compatibility issues. See here.

Note that the field data is identified by name. The situation where a super class has a field with the same name as a subclass must be avoided.

  • Field Details

  • Constructor Details

    • CompatibleFieldSerializer

      public CompatibleFieldSerializer(Kryo kryo, Class type)
    • CompatibleFieldSerializer

      public CompatibleFieldSerializer(Kryo kryo, Class type, FieldSerializerConfig config)
  • Method Details

    • write

      public void write(Kryo kryo, Output output, T object)
      Description copied from class: FieldSerializer
      This method can be called for different fields having the same type. Even though the raw type is the same, if the type is generic, it could happen that different concrete classes are used to instantiate it. Therefore, in case of different instantiation parameters, the fields analysis should be repeated. TODO: Cache serializer instances generated for a given set of generic parameters. Reuse it later instead of recomputing every time.
      Overrides:
      write in class FieldSerializer<T,FieldSerializerConfig>
      Parameters:
      object - May be null if Serializer.getAcceptsNull() is true.
    • read

      public T read(Kryo kryo, Input input, Class<T> type)
      Description copied from class: Serializer
      Reads bytes and returns a new object of the specified concrete type.

      Before Kryo can be used to read child objects, Kryo.reference(Object) must be called with the parent object to ensure it can be referenced by the child objects. Any serializer that uses Kryo to read a child object may need to be reentrant.

      This method should not be called directly, instead this serializer can be passed to Kryo read methods that accept a serialier.

      Overrides:
      read in class FieldSerializer<T,FieldSerializerConfig>
      Returns:
      May be null if Serializer.getAcceptsNull() is true.