How to dynamically scale debounce of burst emission stream?

Question

I've got a buffered stream, waiting for a predetermined amount of silence time, before publishing a list of elements that have been buffered:

INTEGERS
     .share()
     .buffer(INTEGERS.debounce(DEBOUNCE_TIME,TimeUnit.MILLISECONDS,scheduler))
     .map { durations ->
       ... 
     }

I'd like to make DEBOUNCE_TIME dynamically adjust depending on the average of the buffered items, but I'm having a hard time figuring out how to achieve this.

Answer 1

You could defer the debounce, take one item of it and trigger repeat once the new debounce value has been determined:

int DEBOUNCE_TIME = 100;
AtomicInteger debounceTime = new AtomicInteger(DEBOUNCE_TIME);
PublishSubject<Integer> mayRepeat = PublishSubject.create();

AtomicInteger counter = new AtomicInteger();

Observable<Integer> INTEGERS =
        Observable.fromArray(10, 20, 200, 250, 300, 550, 600, 650, 700, 1200)
        .flatMap(v -> Observable.timer(v, TimeUnit.MILLISECONDS)
                .map(w -> counter.incrementAndGet()));

INTEGERS.publish(o ->
        o.buffer(
            Observable.defer(() ->
                o.debounce(
                    debounceTime.get(), TimeUnit.MILLISECONDS)
            )
            .take(1)
            .repeatWhen(v -> v.zipWith(mayRepeat, (a, b) -> b))
        )
    )
    .map(list -> {
        int nextDebounce = Math.min(100, list.size() * 100);
        debounceTime.set(nextDebounce);
        mayRepeat.onNext(1);
        return list;
    })
    .blockingSubscribe(System.out::println);

This prints:

[1, 2]
[3, 4, 5]
[6, 7, 8, 9]
[10]