In the Go SDK this optimization is handled on the SDK side, inthe pardo execution node not one the runner side of the FnAPI
But i think I'm about to learn that FnApiDoFnRunner is something that runs on the Java SDK side rather than on the runner side, despite the name. On Fri, May 1, 2020, 9:02 PM Reuven Lax <[email protected]> wrote: > Ah - so we don't implement the optimization of not expanding the windows > if not necessary? > > On Fri, May 1, 2020 at 8:56 PM Luke Cwik <[email protected]> wrote: > >> In all the processElementYYY methods the currentWindow is assigned as can >> be seen here as we loop over the set of windows: >> >> https://github.com/apache/beam/blob/9bb2990c0f6c08dd33d9c6fa1fd91842c644a8e3/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnApiDoFnRunner.java#L738 >> >> On Fri, May 1, 2020 at 8:51 PM Reuven Lax <[email protected]> wrote: >> >>> In Beam a WindowedValue can can contain multiple windows, because an >>> element can be in multiple windows at once (for example, sliding windows). >>> Usually we keep these elements unexpanded, but if the user's doFn observes >>> the window then we have to "explode" the element out, and we run the >>> process function once per window. e.g. if the process function looks like >>> this >>> >>> @ProcessElement >>> public void process(@Element T e, IntervalWindow w) >>> >>> In SimpleDoFnRunner we do this inside processElement. However I can't >>> find the equivalent code in FnApiDoFnRunner. How does window explosion work >>> in the portable runner? >>> >>> Reuven >>> >>
