/*
* Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package reactor.core.publisher;
import java.util.Iterator;
import java.util.Objects;
import java.util.function.BiFunction;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
/**
* Pairwise combines elements of a publisher and an iterable sequence through a function.
*
* @param <T> the main source value type
* @param <U> the iterable source value type
* @param <R> the result type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class FluxZipIterable<T, U, R> extends FluxSource<T, R> {
final Iterable<? extends U> other;
final BiFunction<? super T, ? super U, ? extends R> zipper;
FluxZipIterable(Flux<? extends T> source,
Iterable<? extends U> other,
BiFunction<? super T, ? super U, ? extends R> zipper) {
super(source);
this.other = Objects.requireNonNull(other, "other");
this.zipper = Objects.requireNonNull(zipper, "zipper");
}
@Override
public void subscribe(Subscriber<? super R> s) {
Iterator<? extends U> it;
try {
it = Objects.requireNonNull(other.iterator(),
"The other iterable produced a null iterator");
}
catch (Throwable e) {
Operators.error(s, Operators.onOperatorError(e));
return;
}
boolean b;
try {
b = it.hasNext();
}
catch (Throwable e) {
Operators.error(s, Operators.onOperatorError(e));
return;
}
if (!b) {
Operators.complete(s);
return;
}
source.subscribe(new ZipSubscriber<>(s, it, zipper));
}
static final class ZipSubscriber<T, U, R>
implements InnerOperator<T, R> {
final Subscriber<? super R> actual;
final Iterator<? extends U> it;
final BiFunction<? super T, ? super U, ? extends R> zipper;
Subscription s;
boolean done;
ZipSubscriber(Subscriber<? super R> actual,
Iterator<? extends U> it,
BiFunction<? super T, ? super U, ? extends R> zipper) {
this.actual = actual;
this.it = it;
this.zipper = zipper;
}
@Override
public Object scan(Attr key) {
switch (key){
case TERMINATED:
return done;
case PARENT:
return s;
}
return InnerOperator.super.scan(key);
}
@Override
public void onSubscribe(Subscription s) {
if (Operators.validate(this.s, s)) {
this.s = s;
actual.onSubscribe(this);
}
}
@Override
public void onNext(T t) {
if (done) {
Operators.onNextDropped(t);
return;
}
U u;
try {
u = it.next();
}
catch (Throwable e) {
done = true;
actual.onError(Operators.onOperatorError(s, e, t));
return;
}
R r;
try {
r = Objects.requireNonNull(zipper.apply(t, u),
"The zipper returned a null value");
}
catch (Throwable e) {
done = true;
actual.onError(Operators.onOperatorError(s, e, t));
return;
}
actual.onNext(r);
boolean b;
try {
b = it.hasNext();
}
catch (Throwable e) {
done = true;
actual.onError(Operators.onOperatorError(s, e, t));
return;
}
if (!b) {
done = true;
s.cancel();
actual.onComplete();
}
}
@Override
public void onError(Throwable t) {
if (done) {
Operators.onErrorDropped(t);
return;
}
done = true;
actual.onError(t);
}
@Override
public void onComplete() {
if (done) {
return;
}
done = true;
actual.onComplete();
}
@Override
public Subscriber<? super R> actual() {
return actual;
}
@Override
public void request(long n) {
s.request(n);
}
@Override
public void cancel() {
s.cancel();
}
}
}