/**
* 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.observable;
import java.util.concurrent.atomic.
AtomicReference;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.exceptions.
Exceptions;
import io.reactivex.functions.
BiFunction;
import io.reactivex.internal.disposables.
DisposableHelper;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.observers.
SerializedObserver;
public final class
ObservableWithLatestFrom<T, U, R> extends
AbstractObservableWithUpstream<T, R> {
final
BiFunction<? super T, ? super U, ? extends R>
combiner;
final
ObservableSource<? extends U>
other;
public
ObservableWithLatestFrom(
ObservableSource<T>
source,
BiFunction<? super T, ? super U, ? extends R>
combiner,
ObservableSource<? extends U>
other) {
super(
source);
this.
combiner =
combiner;
this.
other =
other;
}
@
Override
public void
subscribeActual(
Observer<? super R>
t) {
final
SerializedObserver<R>
serial = new
SerializedObserver<R>(
t);
final
WithLatestFromObserver<T, U, R>
wlf = new
WithLatestFromObserver<T, U, R>(
serial,
combiner);
serial.
onSubscribe(
wlf);
other.
subscribe(new
WithLatestFromOtherObserver(
wlf));
source.
subscribe(
wlf);
}
static final class
WithLatestFromObserver<T, U, R> extends
AtomicReference<U> implements
Observer<T>,
Disposable {
private static final long
serialVersionUID = -312246233408980075L;
final
Observer<? super R>
downstream;
final
BiFunction<? super T, ? super U, ? extends R>
combiner;
final
AtomicReference<
Disposable>
upstream = new
AtomicReference<
Disposable>();
final
AtomicReference<
Disposable>
other = new
AtomicReference<
Disposable>();
WithLatestFromObserver(
Observer<? super R>
actual,
BiFunction<? super T, ? super U, ? extends R>
combiner) {
this.
downstream =
actual;
this.
combiner =
combiner;
}
@
Override
public void
onSubscribe(
Disposable d) {
DisposableHelper.
setOnce(this.
upstream,
d);
}
@
Override
public void
onNext(T
t) {
U
u =
get();
if (
u != null) {
R
r;
try {
r =
ObjectHelper.
requireNonNull(
combiner.
apply(
t,
u), "The combiner returned a null value");
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
dispose();
downstream.
onError(
e);
return;
}
downstream.
onNext(
r);
}
}
@
Override
public void
onError(
Throwable t) {
DisposableHelper.
dispose(
other);
downstream.
onError(
t);
}
@
Override
public void
onComplete() {
DisposableHelper.
dispose(
other);
downstream.
onComplete();
}
@
Override
public void
dispose() {
DisposableHelper.
dispose(
upstream);
DisposableHelper.
dispose(
other);
}
@
Override
public boolean
isDisposed() {
return
DisposableHelper.
isDisposed(
upstream.
get());
}
public boolean
setOther(
Disposable o) {
return
DisposableHelper.
setOnce(
other,
o);
}
public void
otherError(
Throwable e) {
DisposableHelper.
dispose(
upstream);
downstream.
onError(
e);
}
}
final class
WithLatestFromOtherObserver implements
Observer<U> {
private final
WithLatestFromObserver<T, U, R>
parent;
WithLatestFromOtherObserver(
WithLatestFromObserver<T, U, R>
parent) {
this.
parent =
parent;
}
@
Override
public void
onSubscribe(
Disposable d) {
parent.
setOther(
d);
}
@
Override
public void
onNext(U
t) {
parent.
lazySet(
t);
}
@
Override
public void
onError(
Throwable t) {
parent.
otherError(
t);
}
@
Override
public void
onComplete() {
// nothing to do, the wlf will complete on its own pace
}
}
}