/*
* 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.concurrent.
RejectedExecutionException;
import java.util.concurrent.atomic.
AtomicReferenceFieldUpdater;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Disposable;
import reactor.core.scheduler.
Scheduler;
import reactor.util.annotation.
Nullable;
/**
* Schedules the emission of the value or completion of the wrapped Mono via
* the given Scheduler.
*
* @param <T> the value type
*/
final class
MonoPublishOn<T> extends
MonoOperator<T, T> {
final
Scheduler scheduler;
MonoPublishOn(
Mono<? extends T>
source,
Scheduler scheduler) {
super(
source);
this.
scheduler =
scheduler;
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
source.
subscribe(new
PublishOnSubscriber<T>(
actual,
scheduler));
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
RUN_ON) return
scheduler;
return super.scanUnsafe(
key);
}
static final class
PublishOnSubscriber<T>
implements
InnerOperator<T, T>,
Runnable {
final
CoreSubscriber<? super T>
actual;
final
Scheduler scheduler;
Subscription s;
volatile
Disposable future;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
PublishOnSubscriber,
Disposable>
FUTURE =
AtomicReferenceFieldUpdater.
newUpdater(
PublishOnSubscriber.class,
Disposable.class,
"future");
volatile T
value;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
PublishOnSubscriber,
Object>
VALUE =
AtomicReferenceFieldUpdater.
newUpdater(
PublishOnSubscriber.class,
Object.class,
"value");
volatile
Throwable error;
PublishOnSubscriber(
CoreSubscriber<? super T>
actual,
Scheduler scheduler) {
this.
actual =
actual;
this.
scheduler =
scheduler;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
CANCELLED) return
future ==
OperatorDisposables.
DISPOSED;
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
ERROR) return
error;
if (
key ==
Attr.
RUN_ON) return
scheduler;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
value =
t;
trySchedule(this, null,
t);
}
@
Override
public void
onError(
Throwable t) {
error =
t;
trySchedule(null,
t, null);
}
@
Override
public void
onComplete() {
if (
value == null) {
trySchedule(null, null, null);
}
}
void
trySchedule(
@
Nullable Subscription subscription,
@
Nullable Throwable suppressed,
@
Nullable Object dataSignal) {
if(
future != null){
return;
}
try {
future = this.
scheduler.
schedule(this);
}
catch (
RejectedExecutionException ree) {
actual.
onError(
Operators.
onRejectedExecution(
ree,
subscription,
suppressed,
dataSignal,
actual.
currentContext()));
}
}
@
Override
public void
request(long
n) {
s.
request(
n);
}
@
Override
public void
cancel() {
Disposable c =
future;
if (
c !=
OperatorDisposables.
DISPOSED) {
c =
FUTURE.
getAndSet(this,
OperatorDisposables.
DISPOSED);
if (
c != null && !
OperatorDisposables.
isDisposed(
c)) {
c.
dispose();
}
value = null;
}
s.
cancel();
}
@
Override
@
SuppressWarnings("unchecked")
public void
run() {
if (
OperatorDisposables.
isDisposed(
future)) {
return;
}
T
v = (T)
VALUE.
getAndSet(this, null);
if (
v != null) {
actual.
onNext(
v);
actual.
onComplete();
}
else {
Throwable e =
error;
if (
e != null) {
actual.
onError(
e);
}
else {
actual.
onComplete();
}
}
}
}
}