io.reactivex.internal.operators.maybe.MaybeFlatMapSingleElement Maven / Gradle / Ivy
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/**
* 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.maybe;
import java.util.concurrent.atomic.AtomicReference;
import io.reactivex.*;
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;
/**
* Maps the success value of the source MaybeSource into a Single.
* History: 2.0.2 - experimental
* @param the input value type
* @param the result value type
* @since 2.1
*/
public final class MaybeFlatMapSingleElement extends Maybe {
final MaybeSource source;
final Function super T, ? extends SingleSource extends R>> mapper;
public MaybeFlatMapSingleElement(MaybeSource source, Function super T, ? extends SingleSource extends R>> mapper) {
this.source = source;
this.mapper = mapper;
}
@Override
protected void subscribeActual(MaybeObserver super R> downstream) {
source.subscribe(new FlatMapMaybeObserver(downstream, mapper));
}
static final class FlatMapMaybeObserver
extends AtomicReference
implements MaybeObserver, Disposable {
private static final long serialVersionUID = 4827726964688405508L;
final MaybeObserver super R> downstream;
final Function super T, ? extends SingleSource extends R>> mapper;
FlatMapMaybeObserver(MaybeObserver super R> actual, Function super T, ? extends SingleSource extends R>> mapper) {
this.downstream = actual;
this.mapper = mapper;
}
@Override
public void dispose() {
DisposableHelper.dispose(this);
}
@Override
public boolean isDisposed() {
return DisposableHelper.isDisposed(get());
}
@Override
public void onSubscribe(Disposable d) {
if (DisposableHelper.setOnce(this, d)) {
downstream.onSubscribe(this);
}
}
@Override
public void onSuccess(T value) {
SingleSource extends R> ss;
try {
ss = ObjectHelper.requireNonNull(mapper.apply(value), "The mapper returned a null SingleSource");
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
onError(ex);
return;
}
ss.subscribe(new FlatMapSingleObserver(this, downstream));
}
@Override
public void onError(Throwable e) {
downstream.onError(e);
}
@Override
public void onComplete() {
downstream.onComplete();
}
}
static final class FlatMapSingleObserver implements SingleObserver {
final AtomicReference parent;
final MaybeObserver super R> downstream;
FlatMapSingleObserver(AtomicReference parent, MaybeObserver super R> downstream) {
this.parent = parent;
this.downstream = downstream;
}
@Override
public void onSubscribe(final Disposable d) {
DisposableHelper.replace(parent, d);
}
@Override
public void onSuccess(final R value) {
downstream.onSuccess(value);
}
@Override
public void onError(final Throwable e) {
downstream.onError(e);
}
}
}