Add accessors for next refill timestamp, number tokens remaining in bucket and capacity

[bbeck]

Add accessors for next refill timestamp, number tokens remaining in bucket and capacity

[bbeck]

The getCapacity and getNumTokensRemaining methods would be really easy to add.

The getNextRefillTimestamp method would be substantially harder and require some non-backwards compatible redesigning as the refill strategy is abstracted away from the actual token bucket implementation. Can you share the use case that requires you to know how long until you'll receive tokens?

[mmadson]

Thanks for the response!

The use case I'm considering using this for is rate limiting a web service API. Ideally we'd like to respond to successful requests with the following response headers:

RateLimit-Limit
RateLimit-Remaining
RateLimit-Cost
RateLimit-Reset

Limit would be the max capacity for a user's token bucket, i.e., how many tokens they get when the current interval ends thus refilling their bucket.

Remaining would be the current size of the token bucket, i.e., number of tokens remaining in the bucket for the current interval.

Cost is how many tokens a user needs to make a the request.

Reset is the UTC timestamp for when the current interval ends and the user's token bucket is set to Limit (capacity).

So the only missing piece of the puzzle is getting the timestamp of the next refill.

What about adding an accessor for the timestamp to both the TokenBucket and the RefillStrategy and having the TokenBucket call it to get the time of the next refill. For RefillStrategies that are not time based, they could return null or 0?

Thanks!

[bbeck]

Version 1.5 has been built and should show up in maven central within the next few hours.

[mmadson]

I'm simply amazed by your responsiveness and efficiency. Thanks again!