/*
* 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.
Iterator;
import java.util.
Objects;
import java.util.concurrent.atomic.
AtomicIntegerFieldUpdater;
import org.reactivestreams.
Publisher;
import reactor.core.
CoreSubscriber;
/**
* Concatenates a fixed array of Publishers' values.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxConcatIterable<T> extends
Flux<T> implements
SourceProducer<T> {
final
Iterable<? extends
Publisher<? extends T>>
iterable;
FluxConcatIterable(
Iterable<? extends
Publisher<? extends T>>
iterable) {
this.
iterable =
Objects.
requireNonNull(
iterable, "iterable");
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
Iterator<? extends
Publisher<? extends T>>
it;
try {
it =
Objects.
requireNonNull(
iterable.
iterator(),
"The Iterator returned is null");
}
catch (
Throwable e) {
Operators.
error(
actual,
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
ConcatIterableSubscriber<T>
parent = new
ConcatIterableSubscriber<>(
actual,
it);
actual.
onSubscribe(
parent);
if (!
parent.
isCancelled()) {
parent.
onComplete();
}
}
@
Override
public
Object scanUnsafe(
Attr key) {
return null; //no particular key to be represented, still useful in hooks
}
static final class
ConcatIterableSubscriber<T>
extends
Operators.
MultiSubscriptionSubscriber<T, T> {
final
Iterator<? extends
Publisher<? extends T>>
it;
volatile int
wip;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
ConcatIterableSubscriber>
WIP =
AtomicIntegerFieldUpdater.
newUpdater(
ConcatIterableSubscriber.class,
"wip");
long
produced;
ConcatIterableSubscriber(
CoreSubscriber<? super T>
actual,
Iterator<? extends
Publisher<? extends T>>
it) {
super(
actual);
this.
it =
it;
}
@
Override
public void
onNext(T
t) {
produced++;
actual.
onNext(
t);
}
@
Override
public void
onComplete() {
if (
WIP.
getAndIncrement(this) == 0) {
Iterator<? extends
Publisher<? extends T>>
a = this.
it;
do {
if (
isCancelled()) {
return;
}
boolean
b;
try {
b =
a.
hasNext();
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(this,
e,
actual.
currentContext()));
return;
}
if (
isCancelled()) {
return;
}
if (!
b) {
actual.
onComplete();
return;
}
Publisher<? extends T>
p;
try {
p =
Objects.
requireNonNull(
it.
next(),
"The Publisher returned by the iterator is null");
}
catch (
Throwable e) {
actual.
onError(
Operators.
onOperatorError(this,
e,
actual.
currentContext()));
return;
}
if (
isCancelled()) {
return;
}
long
c =
produced;
if (
c != 0L) {
produced = 0L;
produced(
c);
}
p.
subscribe(this);
if (
isCancelled()) {
return;
}
}
while (
WIP.
decrementAndGet(this) != 0);
}
}
}
}