public void close() {
final Throwable throwable = throwableHolder.get();
if (throwable != null) {
throwableHolder.set(null);
throw Throwables.propagate(throwable);
}
}
/**
* An {@link Enumerator} that gets its rows from a {@link BlockingQueue}. There are other fields
* to signal errors and end-of-data.
*/
private static class BlockingQueueEnumerator<E> implements Enumerator<E> {
final BlockingQueue<E> queue = new ArrayBlockingQueue<>(1000);
final AtomicBoolean done = new AtomicBoolean(false);
final Holder<Throwable> throwableHolder = Holder.of(null);
E next;
public E current() {
if (next == null) {
throw new NoSuchElementException();
}
return next;
}
public boolean moveNext() {
for (; ; ) {
next = queue.poll();
if (next != null) {
return true;
}
if (done.get()) {
close();
return false;
}
}
}
public void reset() {}
public void close() {
final Throwable throwable = throwableHolder.get();
if (throwable != null) {
throwableHolder.set(null);
throw Throwables.propagate(throwable);
}
}
}