[GitHub] flink issue #2768: [FLINK-5023][FLINK-5024] Add SimpleStateDescriptor to cla...

[shixiaogang <gi...@git.apache.org>]

Github user shixiaogang commented on the issue:

    https://github.com/apache/flink/pull/2768
  
    @StephanEwen  Thanks a lot for your comments. 
    
    **Removing `clear()` from `State`**
    
    This change is suggested by @aljoscha who wants to let broadcast states share the same interface (see the discussion in [FLINK-5023](https://issues.apache.org/jira/browse/FLINK-5023)) . As mentioned, the broadcast states are read-only in some cases. Hence it's suggested not to provide the `clear()` method in the base `State` interface.
    
    **Changing the `State` interface**
    
    The `State` interface is typed because I want to provide the `get()` method for all states so that we can retrieve the data in the state (under the current key for keyed states). The functionality is already provided by all states except `ValueState` who provides the same functionality with the `value()` method. Providing the method for all states can help reduce some duplicated code in the implementation. It also makes sense for read-only states mentioned above.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---