/**
* Tests that the given {@link GroupAlsoByWindowsDoFn} implementation combines elements per
* session window correctly according to the provided {@link CombineFn}.
*/
public static void combinesElementsPerSessionWithEndOfWindowTimestamp(
GroupAlsoByWindowsDoFnFactory<String, Long, Long> gabwFactory,
CombineFn<Long, ?, Long> combineFn)
throws Exception {
WindowingStrategy<?, IntervalWindow> windowingStrategy =
WindowingStrategy.of(Sessions.withGapDuration(Duration.millis(10)))
.withOutputTimeFn(OutputTimeFns.outputAtEndOfWindow());
BoundedWindow secondWindow = window(15, 25);
List<WindowedValue<KV<String, Long>>> result =
runGABW(
gabwFactory,
windowingStrategy,
"k",
WindowedValue.of(1L, new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING),
WindowedValue.of(2L, new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING),
WindowedValue.of(4L, new Instant(15), Arrays.asList(secondWindow), PaneInfo.NO_FIRING));
assertThat(result, hasSize(2));
BoundedWindow firstResultWindow = window(0, 15);
TimestampedValue<KV<String, Long>> item0 = getOnlyElementInWindow(result, firstResultWindow);
assertThat(item0.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(1L, 2L))));
assertThat(item0.getTimestamp(), equalTo(firstResultWindow.maxTimestamp()));
TimestampedValue<KV<String, Long>> item1 = getOnlyElementInWindow(result, secondWindow);
assertThat(item1.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(4L))));
assertThat(item1.getTimestamp(), equalTo(secondWindow.maxTimestamp()));
}
/**
* Tests that the given GABW implementation correctly groups elements into merged sessions with
* output timestamps at the end of the merged window.
*/
public static void groupsElementsInMergedSessionsWithLatestTimestamp(
GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory)
throws Exception {
WindowingStrategy<?, IntervalWindow> windowingStrategy =
WindowingStrategy.of(Sessions.withGapDuration(Duration.millis(10)))
.withOutputTimeFn(OutputTimeFns.outputAtLatestInputTimestamp());
BoundedWindow unmergedWindow = window(15, 25);
List<WindowedValue<KV<String, Iterable<String>>>> result =
runGABW(
gabwFactory,
windowingStrategy,
"k",
WindowedValue.of(
"v1", new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING),
WindowedValue.of(
"v2", new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING),
WindowedValue.of(
"v3", new Instant(15), Arrays.asList(unmergedWindow), PaneInfo.NO_FIRING));
assertThat(result, hasSize(2));
BoundedWindow mergedWindow = window(0, 15);
TimestampedValue<KV<String, Iterable<String>>> item0 =
getOnlyElementInWindow(result, mergedWindow);
assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2"));
assertThat(item0.getTimestamp(), equalTo(new Instant(5)));
TimestampedValue<KV<String, Iterable<String>>> item1 =
getOnlyElementInWindow(result, unmergedWindow);
assertThat(item1.getValue().getValue(), contains("v3"));
assertThat(item1.getTimestamp(), equalTo(new Instant(15)));
}