/**
* 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.
Callable;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.functions.
BiConsumer;
import io.reactivex.internal.disposables.*;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.internal.fuseable.
FuseToObservable;
import io.reactivex.plugins.
RxJavaPlugins;
public final class
ObservableCollectSingle<T, U> extends
Single<U> implements
FuseToObservable<U> {
final
ObservableSource<T>
source;
final
Callable<? extends U>
initialSupplier;
final
BiConsumer<? super U, ? super T>
collector;
public
ObservableCollectSingle(
ObservableSource<T>
source,
Callable<? extends U>
initialSupplier,
BiConsumer<? super U, ? super T>
collector) {
this.
source =
source;
this.
initialSupplier =
initialSupplier;
this.
collector =
collector;
}
@
Override
protected void
subscribeActual(
SingleObserver<? super U>
t) {
U
u;
try {
u =
ObjectHelper.
requireNonNull(
initialSupplier.
call(), "The initialSupplier returned a null value");
} catch (
Throwable e) {
EmptyDisposable.
error(
e,
t);
return;
}
source.
subscribe(new
CollectObserver<T, U>(
t,
u,
collector));
}
@
Override
public
Observable<U>
fuseToObservable() {
return
RxJavaPlugins.
onAssembly(new
ObservableCollect<T, U>(
source,
initialSupplier,
collector));
}
static final class
CollectObserver<T, U> implements
Observer<T>,
Disposable {
final
SingleObserver<? super U>
downstream;
final
BiConsumer<? super U, ? super T>
collector;
final U
u;
Disposable upstream;
boolean
done;
CollectObserver(
SingleObserver<? super U>
actual, U
u,
BiConsumer<? super U, ? super T>
collector) {
this.
downstream =
actual;
this.
collector =
collector;
this.
u =
u;
}
@
Override
public void
onSubscribe(
Disposable d) {
if (
DisposableHelper.
validate(this.
upstream,
d)) {
this.
upstream =
d;
downstream.
onSubscribe(this);
}
}
@
Override
public void
dispose() {
upstream.
dispose();
}
@
Override
public boolean
isDisposed() {
return
upstream.
isDisposed();
}
@
Override
public void
onNext(T
t) {
if (
done) {
return;
}
try {
collector.
accept(
u,
t);
} catch (
Throwable e) {
upstream.
dispose();
onError(
e);
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
RxJavaPlugins.
onError(
t);
return;
}
done = true;
downstream.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
downstream.
onSuccess(
u);
}
}
}