/*
* 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.
RejectedExecutionException;
import java.util.concurrent.
TimeUnit;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Disposable;
import reactor.core.scheduler.
Scheduler;
import reactor.util.annotation.
Nullable;
/**
* Emits the first value emitted by a given source publisher, delayed by some time amount
* with the help of a ScheduledExecutorService instance or a generic function callback that
* wraps other form of async-delayed execution of tasks.
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
* @author Simon Baslé
* TODO : Review impl
*/
final class
MonoDelayElement<T> extends
MonoOperator<T, T> {
final
Scheduler timedScheduler;
final long
delay;
final
TimeUnit unit;
MonoDelayElement(
Mono<? extends T>
source, long
delay,
TimeUnit unit,
Scheduler timedScheduler) {
super(
source);
this.
delay =
delay;
this.
unit =
Objects.
requireNonNull(
unit, "unit");
this.
timedScheduler =
Objects.
requireNonNull(
timedScheduler, "timedScheduler");
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
source.
subscribe(new
DelayElementSubscriber<>(
actual,
timedScheduler,
delay,
unit));
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
RUN_ON) return
timedScheduler;
return super.scanUnsafe(
key);
}
static final class
DelayElementSubscriber<T> extends
Operators.
MonoSubscriber<T,T> {
final long
delay;
final
Scheduler scheduler;
final
TimeUnit unit;
Subscription s;
volatile
Disposable task;
boolean
done;
DelayElementSubscriber(
CoreSubscriber<? super T>
actual,
Scheduler scheduler,
long
delay,
TimeUnit unit) {
super(
actual);
this.
scheduler =
scheduler;
this.
delay =
delay;
this.
unit =
unit;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) return
done;
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
RUN_ON) return
scheduler;
return super.scanUnsafe(
key);
}
@
Override
public void
cancel() {
super.cancel();
if (
task != null) {
task.
dispose();
}
if (
s !=
Operators.
cancelledSubscription()) {
s.
cancel();
}
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
s.
request(
Long.
MAX_VALUE);
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t,
actual.
currentContext());
return;
}
this.
done = true;
try {
this.
task =
scheduler.
schedule(() ->
complete(
t),
delay,
unit);
}
catch (
RejectedExecutionException ree) {
throw
Operators.
onRejectedExecution(
ree, this, null,
t,
actual.
currentContext());
}
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
this.
done = true;
actual.
onComplete();
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t,
actual.
currentContext());
return;
}
this.
done = true;
actual.
onError(
t);
}
}
}