debounce()

Implementation Notes

Time is measured on a best-effort basis and may not be suitable for cases where a high precision clock is required. For a version of this that pauses the stream instead of dropping elements, see the throttle()Gatherer.

Signature

debounce(int amount, Duration duration)

• amount - A positive number of elements to allow over the duration
• duration - A non-null Duration over which to limit element production

Examples

Limit to 2 per 50 milliseconds

This shows a debouncer that keeps 2 elements every 50ms. First we record the start time so we can crudely measure elapsed time in milliseconds. Next, we start a range of Integer objects and debounce them. We see the original int and the elapsed time in the Pair we map to. Finally, we print the results.

long start = System.currentTimeMillis();

IntStream
    .range(1, 10_000_000)
    .boxed()
    .gather(Gatherers4j.debounce(2, Duration.ofMillis(50)))
    .map(it -> new Pair<>(it, System.currentTimeMillis()-start))
    .forEach(System.out::println);

// Prints
Pair[first=1, second=12]
Pair[first=2, second=15]
Pair[first=8915384, second=62]
Pair[first=8915385, second=62]