[
https://issues.apache.org/jira/browse/FLINK-5416?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15801847#comment-15801847
]
Eron Wright commented on FLINK-5416:
-------------------------------------
To fix it, the wrapper would assumedly implement `CheckpointedFunction` and
contain logic similar to that found in `AbstractUdfStreamOperator` (notably the
handling of `ListCheckpointed`). Maybe the logic could be encapsulated in
`FunctionUtils` since numerous wrappers exist.
> Function wrappers should support CheckpointedFunction
> ------------------------------------------------------
>
> Key: FLINK-5416
> URL: https://issues.apache.org/jira/browse/FLINK-5416
> Project: Flink
> Issue Type: Bug
> Components: State Backends, Checkpointing
> Reporter: Eron Wright
>
> The `CheckpointedFunction` interface was introduced to provide user functions
> with a context for partitioned state storage. This works for user functions
> that are provided directly to the operator (assuming it extends from
> `AbstractUdfStreamOperator`). However, I see that some operators wrap the
> user function in an internal function (e.g. `WrappingFunction`,
> `InternalWindowFunction`). This defeats the callbacks on
> `CheckpointedFunction` because those wrappers don’t implement
> `CheckpointedFunction`.
> For example, the user function passed to `WindowedStream::apply` will get
> callbacks for `RichFunction` but not for `CheckpointedFunction`.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
