beam-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Aviem Zur (JIRA)" <>
Subject [jira] [Assigned] (BEAM-1276) StateSpecs.combiningValue interface is very awkward to use
Date Sun, 26 Mar 2017 04:21:41 GMT


Aviem Zur reassigned BEAM-1276:

    Assignee:     (was: Aviem Zur)

> StateSpecs.combiningValue interface is very awkward to use
> ----------------------------------------------------------
>                 Key: BEAM-1276
>                 URL:
>             Project: Beam
>          Issue Type: Bug
>          Components: sdk-java-core
>            Reporter: Daniel Mills
>            Priority: Minor
> Using StateSpecs.combiningValue with built in combiners is very verbose.  For example,
to keep a running sum of ints:
> {code}
> @StateId("count")
> private final StateSpec<Object, AccumulatorCombiningState<Integer, int[], Integer>>
countSpec =
>     StateSpecs.combiningValue(
>           Sum.ofIntegers().getAccumulatorCoder(pipeline.getCoderRegistry(), VarIntCoder.of()),
> {code}
> This involves getting a reference to the pipeline into the DoFn, guessing/finding the
proper type parameters for Sum.ofIntegers(), and manually pulling the accumulator coder out.
> For combiners like Sum.ofIntegers() that have a fixed accumulator, the combiningValue
call should be able to deduce that.  Additionally, it would be nice to remove the type of
the accumulator from the StateSpec object, since the user only needs the input and output
types in their code.

This message was sent by Atlassian JIRA

View raw message