The source for my windowed groupByKey experiment is here: https://github.com/tweise/incubator-beam/blob/master/runners/apex/src/main/java/org/apache/beam/runners/apex/translators/functions/ApexGroupByKeyOperator.java
The result is Iterable<V>. In cases such as counting, what is the recommended way to perform the incremental aggregation, without building an intermediate collection? Thomas On Fri, Jun 17, 2016 at 8:27 AM, Thomas Weise <thomas.we...@gmail.com> wrote: > Hi, > > I'm looking into using the GroupAlsoByWindowViaWindowSetDoFn to accumulate > the windowed state with the elements arriving one by one (stream). > > Once the window is complete, I would like to emit an Iterable<V> or > another form of aggregation of the elements. Is the following supposed to > lead to merging of current element with previously received elements for > the same window: > > KeyedWorkItem<K, V> kwi = KeyedWorkItems.elementsWorkItem( > kv.getKey(), > Collections.singletonList(updatedWindowedValue)); > > context.setElement(kwi, getStateInternalsForKey(kwi.key())); > fn.processElement(context); > > The input here are always single elements. > > Thanks, > Thomas > > >
