FasterXML / jackson-dataformats-binary

Uber-project for standard Jackson binary format backends: avro, cbor, ion, protobuf, smile
Apache License 2.0
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(cbor) Introduce the writePOJO (or writeObject) with the element size #329

Open Kieun opened 2 years ago

Kieun commented 2 years ago

CBOR has some variants to optimize the encoded output size to indicate the length of the elements. Jackson CBOR generator has been supporting such feature by introducing some public methods. But, there is no such variant method for writeObject or writePOJO. In order to properly generate the optimized output (some implementation forces to optimize the output due to interoperability), it would be better to have such features in the CBOR generator.

So, new API signature seems to be

public void writePOJO(Object pojo, int elementsToWrite) throws IOException or public void writePOJO(Object pojo, boolean makeDefiniteLength) throws IOException

cowtowncoder commented 2 years ago

I don't think this is possible to implement at that level, unfortunately; CBORGenerator will essentially delegate back to ObjectMapper which does serialization. But this is not to say that it might not be possible to implement support at databind level. It would require significant changes to BeanSerializer, to determine if the number of properties is easy enough to reliably detect (may not be when filtering with @JsonView or alternatives is used, f.ex). But might be doable.

But who knows. I'll leave this open: I agree that it'd be nice to be able to have this work for POJOs too.

cowtowncoder commented 1 year ago

Overlapping with #3, fwtw.