/*
* 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 org.reactivestreams.
Publisher;
import reactor.core.
CoreSubscriber;
import reactor.util.annotation.
Nullable;
/**
* Given a set of source Publishers the values of that Publisher is forwarded to the
* actual which responds first with any signal.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
MonoFirst<T> extends
Mono<T> implements
SourceProducer<T> {
final
Mono<? extends T>[]
array;
final
Iterable<? extends
Mono<? extends T>>
iterable;
@
SafeVarargs
MonoFirst(
Mono<? extends T>...
array) {
this.
array =
Objects.
requireNonNull(
array, "array");
this.
iterable = null;
}
MonoFirst(
Iterable<? extends
Mono<? extends T>>
iterable) {
this.
array = null;
this.
iterable =
Objects.
requireNonNull(
iterable);
}
@
Nullable
Mono<T>
orAdditionalSource(
Mono<? extends T>
other) {
if (
array != null) {
int
n =
array.length;
@
SuppressWarnings("unchecked")
Mono<? extends T>[]
newArray = new
Mono[
n + 1];
System.
arraycopy(
array, 0,
newArray, 0,
n);
newArray[
n] =
other;
return new
MonoFirst<>(
newArray);
}
return null;
}
@
SuppressWarnings("unchecked")
@
Override
//TODO mutualize with FluxFirstEmitting
public void
subscribe(
CoreSubscriber<? super T>
actual) {
Publisher<? extends T>[]
a =
array;
int
n;
if (
a == null) {
n = 0;
a = new
Publisher[8];
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;
}
for (; ; ) {
boolean
b;
try {
b =
it.
hasNext();
}
catch (
Throwable e) {
Operators.
error(
actual,
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
if (!
b) {
break;
}
Publisher<? extends T>
p;
try {
p =
Objects.
requireNonNull(
it.
next(),
"The Publisher returned by the iterator is null");
}
catch (
Throwable e) {
Operators.
error(
actual,
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
if (
n ==
a.length) {
Publisher<? extends T>[]
c = new
Publisher[
n + (
n >> 2)];
System.
arraycopy(
a, 0,
c, 0,
n);
a =
c;
}
a[
n++] =
p;
}
}
else {
n =
a.length;
}
if (
n == 0) {
Operators.
complete(
actual);
return;
}
if (
n == 1) {
Publisher<? extends T>
p =
a[0];
if (
p == null) {
Operators.
error(
actual,
Operators.
onOperatorError(new
NullPointerException("The single source Publisher is null"),
actual.
currentContext()));
}
else {
p.
subscribe(
actual);
}
return;
}
FluxFirstEmitting.
RaceCoordinator<T>
coordinator =
new
FluxFirstEmitting.
RaceCoordinator<>(
n);
coordinator.
subscribe(
a,
n,
actual);
}
@
Override
public
Object scanUnsafe(
Attr key) {
return null; //no particular key to be represented, still useful in hooks
}
}