[SPARK-49939][SQL] Codegen Support for json_object_keys (by Invoke & RuntimeReplaceable)

[panbingkun]

What changes were proposed in this pull request?

The pr aims to add Codegen Support for json_object_keys.

Why are the changes needed?

• improve codegen coverage.
• simplified code.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Pass GA & Existed UT (eg: JsonFunctionsSuite#json_object_keys function)

Was this patch authored or co-authored using generative AI tooling?

No.

[MaxGekk]

Why don't you handle JsonProcessingException?

[panbingkun]

If written as one of the following two styles:

• A.

• B.

• Because:
  JsonProcessingException extends JacksonException and JacksonException extends java.io.IOException

• So, Based on my knowledge that catch java.io.IOException should already be enough to achieve the goal.

[MaxGekk]

+1, LGTM. Merging to master.
Thank you, @panbingkun.

[SubhamSinghal]

@panbingkun Do you plan to add codeGen support for StructsToJson and JsonToStructs expression as well?

[panbingkun]

JsonToStructs

Yes!

[SubhamSinghal]

cool. If you are not planning for StructsToJson, then I will take your code as ref and try to implement it.

[panbingkun]

cool. If you are not planning for StructsToJson, then I will take your code as ref and try to implement it.

I don't think StructsToJson(to_json) is suitable for using Invoke & RuntimeReplaceable to support codegen.
A draft implementation can be found at: #48467

[SubhamSinghal]

sorry for naive question, any reason why to_json is not suitable for using Invoke & RuntimeReplaceable? I was checking proto equivalent function toProtobuf expression which extends RuntimeReplaceable

[panbingkun]

sorry for naive question, any reason why to_json is not suitable for using Invoke & RuntimeReplaceable? I was checking proto equivalent function toProtobuf expression which extends RuntimeReplaceable

If we use Invoke and RuntimeReplaceable to support Codegen for to_json,

• Do we need to create a JacksonGenerator every time? Based on my understanding, if we do this, the performance doesn't seem to be optimal.
• If we only create JacksonGenerator once in to_json, then we have to pass it in the Invoke call, and we must make JacksonGenerator extend Serializable, which will cause more or less changes to the old logic. Variables that may be used in Invoke, such as writer and converter, all have similar issues.