There is no suitable way to get the CurrentKey. I think using StepContext.timerInternals() and StepContext.stateInternals() is better. best, JingsongLee ------------------------------------------------------------------From:Thomas Weise <t...@apache.org>Time:2017 Apr 6 (Thu) 12:45To:dev <dev@beam.apache.org>Subject:StatefulDoFnRunner Hi,
While working on the support for splittable DoFn, I see a few cases where the DoFn runner classes slightly complicate reuse across elements (or make it a bit awkward to implement for the runner). StateInternalsStateCleaner and TimeInternalsCleanupTimer take xxxInternals instances. But since those are key specific, the runner writer has to perform acrobatics to flip the key on these internal instances on a per element basis (to avoid having to recreate the other objects that refer to them). Would it be possible to instead use the factory and retrieve the internals by key? The runner then has the choice to optimize as needed. In general, I think it would be nice if the processing context related classes are designed so that they promote reuse of object instances across elements and bundles and minimize object creation on a per key basis? Thanks, Thomas
