Re: Add MapState for keyed streams

Hi Jark If the state is very big, it may occupy a lot of memory if we return Set>. By wrapping the returned iterator, we can easily implement a method returning Iterable>. Users can use that returned Iterable in the foreach loop. Regards Xiaogang 2016-10-19

Re: Add MapState for keyed streams

Hi Xiaogang, I think maybe return Set> is better than Iterator>. Because users can use foreach on Set but not Iterator, and can use iterator access via set.iterator(). Maybe Map.entrySet() is a more familiar way to users. - Jark Wu > 在 2016年10月19日，下午5:18，SHI

Re: Add MapState for keyed streams

Agreed. contains(K key) should be provided. The iterator() method should return Iterator> instead of Iterator>. Besides, size() may also be provided. With these methods, MapStates appear very similar to Java Maps. Users will be very happy to use them. Regards,

Re: Add MapState for keyed streams

Hi Xiaogang, I really like your proposal and think that this would be a valuable addition to Flink :-) For convenience we could maybe add contains(K key), too. Java's Map interface returns a Set of Entry when calling entrySet() (which is the equivalent of iterator() in our interface). The Entry

[jira] [Created] (FLINK-4856) Add MapState for keyed streams

Xiaogang Shi created FLINK-4856: --- Summary: Add MapState for keyed streams Key: FLINK-4856 URL: https://issues.apache.org/jira/browse/FLINK-4856 Project: Flink Issue Type: New Feature