Github user anmolnar commented on the issue:
https://github.com/apache/zookeeper/pull/690
@yisong-yue
Global state can still be maintained in a static field of a concrete class,
it shouldn't be a problem.
Though, you're probably right about `SnapStream` cannot maintain a state on
its own, I believe because the methods should actually belong to `FileSnap`.
Taking one step back and looking at how `FileSnap` works, I think - in terms of
inheritance - the following would be the best to represent relationships:
```
SnapShot (interface) - represents a single snapshot of the DataTree
|
\\ _ FileSnap (abstract) - implements common methods for all file-based
snapshots
|
\\ _ GzipFileSnap (concrete) - Gzip-compressed file-based snapshot
|
\\ _ SnappyFileSnap (concrete) - Snappy compressed file-based snapshot
|
...
```
In this example, your new methods should go into the right concrete class
whether it's Gzip, Snappy, etc. related or in the abstract `FileSnap` class if
it's some common method.
Of course, this needs to do a bit of a refactor which might not be trivial,
so I wouldn't say we have to do this. I just wanted to give you an idea and get
some feedback from you and the community.
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