Copyright (c) 2016-present, RxJava Contributors. 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.
/** * Copyright (c) 2016-present, RxJava Contributors. * * 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 io.reactivex.internal.operators.flowable; import java.util.*; import java.util.concurrent.atomic.*; import org.reactivestreams.*; import io.reactivex.*; import io.reactivex.disposables.*; import io.reactivex.exceptions.*; import io.reactivex.functions.*; import io.reactivex.internal.functions.ObjectHelper; import io.reactivex.internal.fuseable.SimpleQueue; import io.reactivex.internal.queue.SpscLinkedArrayQueue; import io.reactivex.internal.subscriptions.SubscriptionHelper; import io.reactivex.internal.util.*; import io.reactivex.plugins.RxJavaPlugins; import io.reactivex.processors.UnicastProcessor; public final class FlowableGroupJoin<TLeft, TRight, TLeftEnd, TRightEnd, R> extends AbstractFlowableWithUpstream<TLeft, R> { final Publisher<? extends TRight> other; final Function<? super TLeft, ? extends Publisher<TLeftEnd>> leftEnd; final Function<? super TRight, ? extends Publisher<TRightEnd>> rightEnd; final BiFunction<? super TLeft, ? super Flowable<TRight>, ? extends R> resultSelector; public FlowableGroupJoin( Flowable<TLeft> source, Publisher<? extends TRight> other, Function<? super TLeft, ? extends Publisher<TLeftEnd>> leftEnd, Function<? super TRight, ? extends Publisher<TRightEnd>> rightEnd, BiFunction<? super TLeft, ? super Flowable<TRight>, ? extends R> resultSelector) { super(source); this.other = other; this.leftEnd = leftEnd; this.rightEnd = rightEnd; this.resultSelector = resultSelector; } @Override protected void subscribeActual(Subscriber<? super R> s) { GroupJoinSubscription<TLeft, TRight, TLeftEnd, TRightEnd, R> parent = new GroupJoinSubscription<TLeft, TRight, TLeftEnd, TRightEnd, R>(s, leftEnd, rightEnd, resultSelector); s.onSubscribe(parent); LeftRightSubscriber left = new LeftRightSubscriber(parent, true); parent.disposables.add(left); LeftRightSubscriber right = new LeftRightSubscriber(parent, false); parent.disposables.add(right); source.subscribe(left); other.subscribe(right); } interface JoinSupport { void innerError(Throwable ex); void innerComplete(LeftRightSubscriber sender); void innerValue(boolean isLeft, Object o); void innerClose(boolean isLeft, LeftRightEndSubscriber index); void innerCloseError(Throwable ex); } static final class GroupJoinSubscription<TLeft, TRight, TLeftEnd, TRightEnd, R> extends AtomicInteger implements Subscription, JoinSupport { private static final long serialVersionUID = -6071216598687999801L; final Subscriber<? super R> downstream; final AtomicLong requested; final SpscLinkedArrayQueue<Object> queue; final CompositeDisposable disposables; final Map<Integer, UnicastProcessor<TRight>> lefts; final Map<Integer, TRight> rights; final AtomicReference<Throwable> error; final Function<? super TLeft, ? extends Publisher<TLeftEnd>> leftEnd; final Function<? super TRight, ? extends Publisher<TRightEnd>> rightEnd; final BiFunction<? super TLeft, ? super Flowable<TRight>, ? extends R> resultSelector; final AtomicInteger active; int leftIndex; int rightIndex; volatile boolean cancelled; static final Integer LEFT_VALUE = 1; static final Integer RIGHT_VALUE = 2; static final Integer LEFT_CLOSE = 3; static final Integer RIGHT_CLOSE = 4; GroupJoinSubscription(Subscriber<? super R> actual, Function<? super TLeft, ? extends Publisher<TLeftEnd>> leftEnd, Function<? super TRight, ? extends Publisher<TRightEnd>> rightEnd, BiFunction<? super TLeft, ? super Flowable<TRight>, ? extends R> resultSelector) { this.downstream = actual; this.requested = new AtomicLong(); this.disposables = new CompositeDisposable(); this.queue = new SpscLinkedArrayQueue<Object>(bufferSize()); this.lefts = new LinkedHashMap<Integer, UnicastProcessor<TRight>>(); this.rights = new LinkedHashMap<Integer, TRight>(); this.error = new AtomicReference<Throwable>(); this.leftEnd = leftEnd; this.rightEnd = rightEnd; this.resultSelector = resultSelector; this.active = new AtomicInteger(2); } @Override public void request(long n) { if (SubscriptionHelper.validate(n)) { BackpressureHelper.add(requested, n); } } @Override public void cancel() { if (cancelled) { return; } cancelled = true; cancelAll(); if (getAndIncrement() == 0) { queue.clear(); } } void cancelAll() { disposables.dispose(); } void errorAll(Subscriber<?> a) { Throwable ex = ExceptionHelper.terminate(error); for (UnicastProcessor<TRight> up : lefts.values()) { up.onError(ex); } lefts.clear(); rights.clear(); a.onError(ex); } void fail(Throwable exc, Subscriber<?> a, SimpleQueue<?> q) { Exceptions.throwIfFatal(exc); ExceptionHelper.addThrowable(error, exc); q.clear(); cancelAll(); errorAll(a); } void drain() { if (getAndIncrement() != 0) { return; } int missed = 1; SpscLinkedArrayQueue<Object> q = queue; Subscriber<? super R> a = downstream; for (;;) { for (;;) { if (cancelled) { q.clear(); return; } Throwable ex = error.get(); if (ex != null) { q.clear(); cancelAll(); errorAll(a); return; } boolean d = active.get() == 0; Integer mode = (Integer)q.poll(); boolean empty = mode == null; if (d && empty) { for (UnicastProcessor<?> up : lefts.values()) { up.onComplete(); } lefts.clear(); rights.clear(); disposables.dispose(); a.onComplete(); return; } if (empty) { break; } Object val = q.poll(); if (mode == LEFT_VALUE) { @SuppressWarnings("unchecked") TLeft left = (TLeft)val; UnicastProcessor<TRight> up = UnicastProcessor.<TRight>create(); int idx = leftIndex++; lefts.put(idx, up); Publisher<TLeftEnd> p; try { p = ObjectHelper.requireNonNull(leftEnd.apply(left), "The leftEnd returned a null Publisher"); } catch (Throwable exc) { fail(exc, a, q); return; } LeftRightEndSubscriber end = new LeftRightEndSubscriber(this, true, idx); disposables.add(end); p.subscribe(end); ex = error.get(); if (ex != null) { q.clear(); cancelAll(); errorAll(a); return; } R w; try { w = ObjectHelper.requireNonNull(resultSelector.apply(left, up), "The resultSelector returned a null value"); } catch (Throwable exc) { fail(exc, a, q); return; } // TODO since only left emission calls the actual, it is possible to link downstream backpressure with left's source and not error out if (requested.get() != 0L) { a.onNext(w); BackpressureHelper.produced(requested, 1); } else { fail(new MissingBackpressureException("Could not emit value due to lack of requests"), a, q); return; } for (TRight right : rights.values()) { up.onNext(right); } } else if (mode == RIGHT_VALUE) { @SuppressWarnings("unchecked") TRight right = (TRight)val; int idx = rightIndex++; rights.put(idx, right); Publisher<TRightEnd> p; try { p = ObjectHelper.requireNonNull(rightEnd.apply(right), "The rightEnd returned a null Publisher"); } catch (Throwable exc) { fail(exc, a, q); return; } LeftRightEndSubscriber end = new LeftRightEndSubscriber(this, false, idx); disposables.add(end); p.subscribe(end); ex = error.get(); if (ex != null) { q.clear(); cancelAll(); errorAll(a); return; } for (UnicastProcessor<TRight> up : lefts.values()) { up.onNext(right); } } else if (mode == LEFT_CLOSE) { LeftRightEndSubscriber end = (LeftRightEndSubscriber)val; UnicastProcessor<TRight> up = lefts.remove(end.index); disposables.remove(end); if (up != null) { up.onComplete(); } } else if (mode == RIGHT_CLOSE) { LeftRightEndSubscriber end = (LeftRightEndSubscriber)val; rights.remove(end.index); disposables.remove(end); } } missed = addAndGet(-missed); if (missed == 0) { break; } } } @Override public void innerError(Throwable ex) { if (ExceptionHelper.addThrowable(error, ex)) { active.decrementAndGet(); drain(); } else { RxJavaPlugins.onError(ex); } } @Override public void innerComplete(LeftRightSubscriber sender) { disposables.delete(sender); active.decrementAndGet(); drain(); } @Override public void innerValue(boolean isLeft, Object o) { synchronized (this) { queue.offer(isLeft ? LEFT_VALUE : RIGHT_VALUE, o); } drain(); } @Override public void innerClose(boolean isLeft, LeftRightEndSubscriber index) { synchronized (this) { queue.offer(isLeft ? LEFT_CLOSE : RIGHT_CLOSE, index); } drain(); } @Override public void innerCloseError(Throwable ex) { if (ExceptionHelper.addThrowable(error, ex)) { drain(); } else { RxJavaPlugins.onError(ex); } } } static final class LeftRightSubscriber extends AtomicReference<Subscription> implements FlowableSubscriber<Object>, Disposable { private static final long serialVersionUID = 1883890389173668373L; final JoinSupport parent; final boolean isLeft; LeftRightSubscriber(JoinSupport parent, boolean isLeft) { this.parent = parent; this.isLeft = isLeft; } @Override public void dispose() { SubscriptionHelper.cancel(this); } @Override public boolean isDisposed() { return get() == SubscriptionHelper.CANCELLED; } @Override public void onSubscribe(Subscription s) { SubscriptionHelper.setOnce(this, s, Long.MAX_VALUE); } @Override public void onNext(Object t) { parent.innerValue(isLeft, t); } @Override public void onError(Throwable t) { parent.innerError(t); } @Override public void onComplete() { parent.innerComplete(this); } } static final class LeftRightEndSubscriber extends AtomicReference<Subscription> implements FlowableSubscriber<Object>, Disposable { private static final long serialVersionUID = 1883890389173668373L; final JoinSupport parent; final boolean isLeft; final int index; LeftRightEndSubscriber(JoinSupport parent, boolean isLeft, int index) { this.parent = parent; this.isLeft = isLeft; this.index = index; } @Override public void dispose() { SubscriptionHelper.cancel(this); } @Override public boolean isDisposed() { return get() == SubscriptionHelper.CANCELLED; } @Override public void onSubscribe(Subscription s) { SubscriptionHelper.setOnce(this, s, Long.MAX_VALUE); } @Override public void onNext(Object t) { if (SubscriptionHelper.cancel(this)) { parent.innerClose(isLeft, this); } } @Override public void onError(Throwable t) { parent.innerCloseError(t); } @Override public void onComplete() { parent.innerClose(isLeft, this); } } }