@Test
public void testParallelMerge() {
PublishSubject<String> p1 = PublishSubject.<String>create();
PublishSubject<String> p2 = PublishSubject.<String>create();
PublishSubject<String> p3 = PublishSubject.<String>create();
PublishSubject<String> p4 = PublishSubject.<String>create();
Observable<Observable<String>> fourStreams =
Observable.<Observable<String>>from(p1, p2, p3, p4);
Observable<Observable<String>> twoStreams = Observable.parallelMerge(fourStreams, 2);
Observable<Observable<String>> threeStreams = Observable.parallelMerge(fourStreams, 3);
List<? super Observable<String>> fourList = fourStreams.toList().toBlocking().last();
List<? super Observable<String>> threeList = threeStreams.toList().toBlocking().last();
List<? super Observable<String>> twoList = twoStreams.toList().toBlocking().last();
System.out.println("two list: " + twoList);
System.out.println("three list: " + threeList);
System.out.println("four list: " + fourList);
assertEquals(4, fourList.size());
assertEquals(3, threeList.size());
assertEquals(2, twoList.size());
}
@Test
public void testNumberOfThreads() {
final ConcurrentHashMap<Long, Long> threads = new ConcurrentHashMap<Long, Long>();
// parallelMerge into 3 streams and observeOn for each
// we expect 3 threads in the output
Observable.parallelMerge(getStreams(), 3)
.flatMap(
new Func1<Observable<String>, Observable<String>>() {
@Override
public Observable<String> call(Observable<String> o) {
// for each of the parallel
return o.observeOn(Schedulers.newThread());
}
})
.toBlocking()
.forEach(
new Action1<String>() {
@Override
public void call(String o) {
System.out.println("o: " + o + " Thread: " + Thread.currentThread().getId());
threads.put(Thread.currentThread().getId(), Thread.currentThread().getId());
}
});
assertTrue(
threads.keySet().size()
<= 3); // can be less than since merge doesn't block threads and may not use all of them
}