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.single; import java.util.Iterator; import io.reactivex.*; import io.reactivex.annotations.Nullable; import io.reactivex.disposables.Disposable; import io.reactivex.exceptions.Exceptions; import io.reactivex.functions.Function; import io.reactivex.internal.disposables.DisposableHelper; import io.reactivex.internal.functions.ObjectHelper; import io.reactivex.internal.observers.BasicIntQueueDisposable;
Maps a success value into an Iterable and streams it back as an Observable.
Type parameters:
  • <T> – the source value type
  • <R> – the element type of the Iterable
/** * Maps a success value into an Iterable and streams it back as an Observable. * * @param <T> the source value type * @param <R> the element type of the Iterable */
public final class SingleFlatMapIterableObservable<T, R> extends Observable<R> { final SingleSource<T> source; final Function<? super T, ? extends Iterable<? extends R>> mapper; public SingleFlatMapIterableObservable(SingleSource<T> source, Function<? super T, ? extends Iterable<? extends R>> mapper) { this.source = source; this.mapper = mapper; } @Override protected void subscribeActual(Observer<? super R> observer) { source.subscribe(new FlatMapIterableObserver<T, R>(observer, mapper)); } static final class FlatMapIterableObserver<T, R> extends BasicIntQueueDisposable<R> implements SingleObserver<T> { private static final long serialVersionUID = -8938804753851907758L; final Observer<? super R> downstream; final Function<? super T, ? extends Iterable<? extends R>> mapper; Disposable upstream; volatile Iterator<? extends R> it; volatile boolean cancelled; boolean outputFused; FlatMapIterableObserver(Observer<? super R> actual, Function<? super T, ? extends Iterable<? extends R>> mapper) { this.downstream = actual; this.mapper = mapper; } @Override public void onSubscribe(Disposable d) { if (DisposableHelper.validate(this.upstream, d)) { this.upstream = d; downstream.onSubscribe(this); } } @Override public void onSuccess(T value) { Observer<? super R> a = downstream; Iterator<? extends R> iterator; boolean has; try { iterator = mapper.apply(value).iterator(); has = iterator.hasNext(); } catch (Throwable ex) { Exceptions.throwIfFatal(ex); downstream.onError(ex); return; } if (!has) { a.onComplete(); return; } if (outputFused) { it = iterator; a.onNext(null); a.onComplete(); } else { for (;;) { if (cancelled) { return; } R v; try { v = iterator.next(); } catch (Throwable ex) { Exceptions.throwIfFatal(ex); a.onError(ex); return; } a.onNext(v); if (cancelled) { return; } boolean b; try { b = iterator.hasNext(); } catch (Throwable ex) { Exceptions.throwIfFatal(ex); a.onError(ex); return; } if (!b) { a.onComplete(); return; } } } } @Override public void onError(Throwable e) { upstream = DisposableHelper.DISPOSED; downstream.onError(e); } @Override public void dispose() { cancelled = true; upstream.dispose(); upstream = DisposableHelper.DISPOSED; } @Override public boolean isDisposed() { return cancelled; } @Override public int requestFusion(int mode) { if ((mode & ASYNC) != 0) { outputFused = true; return ASYNC; } return NONE; } @Override public void clear() { it = null; } @Override public boolean isEmpty() { return it == null; } @Nullable @Override public R poll() throws Exception { Iterator<? extends R> iterator = it; if (iterator != null) { R v = ObjectHelper.requireNonNull(iterator.next(), "The iterator returned a null value"); if (!iterator.hasNext()) { it = null; } return v; } return null; } } }