/**
* 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.concurrent.
Callable;
import java.util.concurrent.atomic.
AtomicReference;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.exceptions.*;
import io.reactivex.functions.*;
import io.reactivex.internal.disposables.*;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.plugins.
RxJavaPlugins;
public final class
SingleUsing<T, U> extends
Single<T> {
final
Callable<U>
resourceSupplier;
final
Function<? super U, ? extends
SingleSource<? extends T>>
singleFunction;
final
Consumer<? super U>
disposer;
final boolean
eager;
public
SingleUsing(
Callable<U>
resourceSupplier,
Function<? super U, ? extends
SingleSource<? extends T>>
singleFunction,
Consumer<? super U>
disposer,
boolean
eager) {
this.
resourceSupplier =
resourceSupplier;
this.
singleFunction =
singleFunction;
this.
disposer =
disposer;
this.
eager =
eager;
}
@
Override
protected void
subscribeActual(final
SingleObserver<? super T>
observer) {
final U
resource; // NOPMD
try {
resource =
resourceSupplier.
call();
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
EmptyDisposable.
error(
ex,
observer);
return;
}
SingleSource<? extends T>
source;
try {
source =
ObjectHelper.
requireNonNull(
singleFunction.
apply(
resource), "The singleFunction returned a null SingleSource");
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
if (
eager) {
try {
disposer.
accept(
resource);
} catch (
Throwable exc) {
Exceptions.
throwIfFatal(
exc);
ex = new
CompositeException(
ex,
exc);
}
}
EmptyDisposable.
error(
ex,
observer);
if (!
eager) {
try {
disposer.
accept(
resource);
} catch (
Throwable exc) {
Exceptions.
throwIfFatal(
exc);
RxJavaPlugins.
onError(
exc);
}
}
return;
}
source.
subscribe(new
UsingSingleObserver<T, U>(
observer,
resource,
eager,
disposer));
}
static final class
UsingSingleObserver<T, U> extends
AtomicReference<
Object> implements
SingleObserver<T>,
Disposable {
private static final long
serialVersionUID = -5331524057054083935L;
final
SingleObserver<? super T>
downstream;
final
Consumer<? super U>
disposer;
final boolean
eager;
Disposable upstream;
UsingSingleObserver(
SingleObserver<? super T>
actual, U
resource, boolean
eager,
Consumer<? super U>
disposer) {
super(
resource);
this.
downstream =
actual;
this.
eager =
eager;
this.
disposer =
disposer;
}
@
Override
public void
dispose() {
upstream.
dispose();
upstream =
DisposableHelper.
DISPOSED;
disposeAfter();
}
@
Override
public boolean
isDisposed() {
return
upstream.
isDisposed();
}
@
Override
public void
onSubscribe(
Disposable d) {
if (
DisposableHelper.
validate(this.
upstream,
d)) {
this.
upstream =
d;
downstream.
onSubscribe(this);
}
}
@
SuppressWarnings("unchecked")
@
Override
public void
onSuccess(T
value) {
upstream =
DisposableHelper.
DISPOSED;
if (
eager) {
Object u =
getAndSet(this);
if (
u != this) {
try {
disposer.
accept((U)
u);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
downstream.
onError(
ex);
return;
}
} else {
return;
}
}
downstream.
onSuccess(
value);
if (!
eager) {
disposeAfter();
}
}
@
SuppressWarnings("unchecked")
@
Override
public void
onError(
Throwable e) {
upstream =
DisposableHelper.
DISPOSED;
if (
eager) {
Object u =
getAndSet(this);
if (
u != this) {
try {
disposer.
accept((U)
u);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
e = new
CompositeException(
e,
ex);
}
} else {
return;
}
}
downstream.
onError(
e);
if (!
eager) {
disposeAfter();
}
}
@
SuppressWarnings("unchecked")
void
disposeAfter() {
Object u =
getAndSet(this);
if (
u != this) {
try {
disposer.
accept((U)
u);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
RxJavaPlugins.
onError(
ex);
}
}
}
}
}