/**
* 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 java.util.concurrent.atomic.
AtomicBoolean;
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
ObservableUsing<T, D> extends
Observable<T> {
final
Callable<? extends D>
resourceSupplier;
final
Function<? super D, ? extends
ObservableSource<? extends T>>
sourceSupplier;
final
Consumer<? super D>
disposer;
final boolean
eager;
public
ObservableUsing(
Callable<? extends D>
resourceSupplier,
Function<? super D, ? extends
ObservableSource<? extends T>>
sourceSupplier,
Consumer<? super D>
disposer,
boolean
eager) {
this.
resourceSupplier =
resourceSupplier;
this.
sourceSupplier =
sourceSupplier;
this.
disposer =
disposer;
this.
eager =
eager;
}
@
Override
public void
subscribeActual(
Observer<? super T>
observer) {
D
resource;
try {
resource =
resourceSupplier.
call();
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
EmptyDisposable.
error(
e,
observer);
return;
}
ObservableSource<? extends T>
source;
try {
source =
ObjectHelper.
requireNonNull(
sourceSupplier.
apply(
resource), "The sourceSupplier returned a null ObservableSource");
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
try {
disposer.
accept(
resource);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
EmptyDisposable.
error(new
CompositeException(
e,
ex),
observer);
return;
}
EmptyDisposable.
error(
e,
observer);
return;
}
UsingObserver<T, D>
us = new
UsingObserver<T, D>(
observer,
resource,
disposer,
eager);
source.
subscribe(
us);
}
static final class
UsingObserver<T, D> extends
AtomicBoolean implements
Observer<T>,
Disposable {
private static final long
serialVersionUID = 5904473792286235046L;
final
Observer<? super T>
downstream;
final D
resource;
final
Consumer<? super D>
disposer;
final boolean
eager;
Disposable upstream;
UsingObserver(
Observer<? super T>
actual, D
resource,
Consumer<? super D>
disposer, boolean
eager) {
this.
downstream =
actual;
this.
resource =
resource;
this.
disposer =
disposer;
this.
eager =
eager;
}
@
Override
public void
onSubscribe(
Disposable d) {
if (
DisposableHelper.
validate(this.
upstream,
d)) {
this.
upstream =
d;
downstream.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
downstream.
onNext(
t);
}
@
Override
public void
onError(
Throwable t) {
if (
eager) {
if (
compareAndSet(false, true)) {
try {
disposer.
accept(
resource);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
t = new
CompositeException(
t,
e);
}
}
upstream.
dispose();
downstream.
onError(
t);
} else {
downstream.
onError(
t);
upstream.
dispose();
disposeAfter();
}
}
@
Override
public void
onComplete() {
if (
eager) {
if (
compareAndSet(false, true)) {
try {
disposer.
accept(
resource);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
downstream.
onError(
e);
return;
}
}
upstream.
dispose();
downstream.
onComplete();
} else {
downstream.
onComplete();
upstream.
dispose();
disposeAfter();
}
}
@
Override
public void
dispose() {
disposeAfter();
upstream.
dispose();
}
@
Override
public boolean
isDisposed() {
return
get();
}
void
disposeAfter() {
if (
compareAndSet(false, true)) {
try {
disposer.
accept(
resource);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// can't call actual.onError unless it is serialized, which is expensive
RxJavaPlugins.
onError(
e);
}
}
}
}
}