/*
* 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.Objects;
import java.util.function.Predicate;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
/**
* Relays values while a predicate returns
* true for the values (checked before each value is delivered).
*
* @param <T> the value type
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class FluxTakeWhile<T> extends FluxSource<T, T> {
final Predicate<? super T> predicate;
FluxTakeWhile(Flux<? extends T> source, Predicate<? super T> predicate) {
super(source);
this.predicate = Objects.requireNonNull(predicate, "predicate");
}
@Override
public void subscribe(Subscriber<? super T> s) {
source.subscribe(new TakeWhileSubscriber<>(s, predicate));
}
static final class TakeWhileSubscriber<T>
implements InnerOperator<T, T> {
final Subscriber<? super T> actual;
final Predicate<? super T> predicate;
Subscription s;
boolean done;
TakeWhileSubscriber(Subscriber<? super T> actual, Predicate<? super T> predicate) {
this.actual = actual;
this.predicate = predicate;
}
@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;
}
boolean b;
try {
b = predicate.test(t);
} catch (Throwable e) {
onError(Operators.onOperatorError(s, e, t));
return;
}
if (!b) {
s.cancel();
onComplete();
return;
}
actual.onNext(t);
}
@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 Object scan(Attr key) {
switch (key){
case TERMINATED:
return done;
case PARENT:
return s;
}
return InnerOperator.super.scan(key);
}
@Override
public Subscriber<? super T> actual() {
return actual;
}
@Override
public void request(long n) {
s.request(n);
}
@Override
public void cancel() {
s.cancel();
}
}
}