/** test OffsetRounding with an internal interval rounding on random inputs */
public void testOffsetRoundingRandom() {
for (int i = 0; i < 1000; ++i) {
final long interval = randomIntBetween(1, 100);
Rounding.Interval internalRounding = new Rounding.Interval(interval);
final long offset = randomIntBetween(-100, 100);
Rounding.OffsetRounding rounding = new Rounding.OffsetRounding(internalRounding, offset);
long safetyMargin = Math.abs(interval) + Math.abs(offset); // to prevent range overflow
long value = Math.max(randomLong() - safetyMargin, Long.MIN_VALUE + safetyMargin);
final long key = rounding.roundKey(value);
final long key_next = rounding.roundKey(value + interval);
final long r_value = rounding.round(value);
final long nextRoundingValue = rounding.nextRoundingValue(r_value);
assertThat("Rounding should be idempotent", r_value, equalTo(rounding.round(r_value)));
assertThat(
"Rounded value smaller than unrounded, regardless of offset",
r_value - offset,
lessThanOrEqualTo(value - offset));
assertThat("Key and next_key should differ by one", key_next - key, equalTo(1L));
assertThat(
"Rounded value <= value < next interval start", r_value + interval, greaterThan(value));
assertThat(
"NextRounding value should be interval from rounded value",
r_value + interval,
equalTo(nextRoundingValue));
}
}
/**
* Simple test case to illustrate how Rounding.Offset works on readable input. offset shifts input
* value back before rounding (so here 6 - 7 -> -1) then shifts rounded Value back (here -10
* -> -3)
*/
public void testOffsetRounding() {
final long interval = 10;
final long offset = 7;
Rounding.OffsetRounding rounding =
new Rounding.OffsetRounding(new Rounding.Interval(interval), offset);
assertEquals(-1, rounding.roundKey(6));
assertEquals(-3, rounding.round(6));
assertEquals(7, rounding.nextRoundingValue(-3));
assertEquals(0, rounding.roundKey(7));
assertEquals(7, rounding.round(7));
assertEquals(17, rounding.nextRoundingValue(7));
assertEquals(0, rounding.roundKey(16));
assertEquals(7, rounding.round(16));
assertEquals(1, rounding.roundKey(17));
assertEquals(17, rounding.round(17));
assertEquals(27, rounding.nextRoundingValue(17));
}