Merge "Tweak RateEstimator's alpha value" into udc-qpr-dev

 * {@hide}

 */

class RateEstimator {

    private static final double RATE_ALPHA = 0.5;

    private static final double RATE_ALPHA = 0.7;

    private static final double MINIMUM_DT = 0.0005;

    private Long mLastEventTime;

    @Test

    public void testEstimateCatchesUpQuickly() {

        long nextEventTime = postEvents(mTestStartTime, 10, 20); // 20 events at 100Hz

        long nextEventTime = postEvents(mTestStartTime, 100, 30); // 30 events at 10Hz

        final float firstBurstRate = mEstimator.getRate(nextEventTime);

        assertThat(firstBurstRate).isWithin(10f).of(100);

        assertThat(firstBurstRate).isWithin(2f).of(10);

        nextEventTime += HOURS.toMillis(3); // 3 hours later...

        nextEventTime = postEvents(nextEventTime, 10, 20); // same burst of 20 events at 100Hz

        nextEventTime = postEvents(nextEventTime, 100, 30); // same burst of 30 events at 10Hz

        // Catching up. Rate is not yet 100, since we had a long period of inactivity...

        // Catching up. Rate is not yet 10, since we had a long period of inactivity...

        float secondBurstRate = mEstimator.getRate(nextEventTime);

        assertThat(secondBurstRate).isWithin(10f).of(60);

        assertThat(secondBurstRate).isWithin(1f).of(6);

        // ... but after a few more events, we are there.

        nextEventTime = postEvents(nextEventTime, 10, 10); // 10 more events at 100Hz

        nextEventTime = postEvents(nextEventTime, 100, 10); // 10 more events at 10Hz

        secondBurstRate = mEstimator.getRate(nextEventTime);

        assertThat(secondBurstRate).isWithin(10f).of(100);

        assertThat(secondBurstRate).isWithin(1f).of(10);

    }

    /** @return the next event time. */