[BEAM-6858] Support side inputs injected into a DoFn

• Type: Bug
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: 2.16.0
• Component/s: sdk-java-core
• Labels: Done
• Assignee: Unassigned
• Reporter: Reuven Lax
• Created: 19/Mar/19 00:46
• Updated: 06/Oct/20 21:52
• Resolved: 10/Jun/20 21:47

Description

Beam currently supports injecting main inputs into a DoFn process method. A user can write the following:

@ProcessElement public void process(@Element InputT element)

And Beam will (using ByteBuddy code generation) inject the input element into the process method.

We would like to also support the same for side inputs. For example:

@ProcessElement public void process(@Element InputT element, @SideInput("tag1") String input1, @SideInput("tag2") Integer input2) 

This requires the existing process-method analysis framework to capture these side inputs. The ParDo code would have to verify the type of the side input and include them in the list of side inputs. This would also eliminate the need for the user to explicitly call withSideInputs on the ParDo.

 

Issue Links

• links to: GitHub Pull Request #9275