/*
* Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
*
* 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 reactor.core.publisher;
import java.util.
Objects;
import java.util.concurrent.atomic.
AtomicIntegerFieldUpdater;
import org.reactivestreams.
Subscriber;
import reactor.core.
CoreSubscriber;
import reactor.util.annotation.
Nullable;
/**
* Emits a constant or generated Throwable instance to Subscribers.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxErrorOnRequest<T> extends
Flux<T> implements
SourceProducer<T> {
final
Throwable error;
FluxErrorOnRequest(
Throwable error) {
this.
error =
Objects.
requireNonNull(
error);
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
actual.
onSubscribe(new
ErrorSubscription(
actual,
error));
}
@
Override
public
Object scanUnsafe(
Attr key) {
return null; //no particular key to be represented, still useful in hooks
}
static final class
ErrorSubscription implements
InnerProducer {
final
CoreSubscriber<?>
actual;
final
Throwable error;
volatile int
once;
static final
AtomicIntegerFieldUpdater<
ErrorSubscription>
ONCE =
AtomicIntegerFieldUpdater.
newUpdater(
ErrorSubscription.class, "once");
ErrorSubscription(
CoreSubscriber<?>
actual,
Throwable error) {
this.
actual =
actual;
this.
error =
error;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
if (
ONCE.
compareAndSet(this, 0, 1)) {
actual.
onError(
error);
}
}
}
@
Override
public void
cancel() {
once = 1;
}
@
Override
public
CoreSubscriber actual() {
return
actual;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
ERROR) return
error;
if (
key ==
Attr.
CANCELLED ||
key ==
Attr.
TERMINATED)
return
once == 1;
return
InnerProducer.super.scanUnsafe(
key);
}
}
}