Allow to change MaxSize while running

[bep]

First, thanks for this library, I tested this here and it works great.

I have one challenge (which I may just skip in its first version) though, and that is how to control the size of the cache.

I understand that you can somehow control this by implementing Size() (the same strategy as used by Ristretto, but implementing that in a general way for structs/maps seems to be non-trivial. For my use case I can probably do some approximations.

Which is why I'm lifting the idea about a SetMaxSize method that could be adjust while running to handle "low on memory" situations.

[karlseguin]

40275a3

?

[bep]

Yes, that looks great.

[karlseguin]

This is in master now. Thanks for the suggestion!

[bep]

Just tested it -- works great. I still need to do some thinking about "how to best" do these adjustments, but this is a much simpler mental model than the other one. I think this will be useful to many, thanks again.