/*
* 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.
Callable;
import java.util.concurrent.atomic.
AtomicLongFieldUpdater;
import java.util.concurrent.atomic.
AtomicReferenceFieldUpdater;
import java.util.function.
Function;
import java.util.stream.
Stream;
import org.reactivestreams.
Publisher;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Scannable;
import reactor.util.annotation.
Nullable;
import reactor.util.context.
Context;
final class
MonoFlatMapMany<T, R> extends
FluxFromMonoOperator<T, R> {
final
Function<? super T, ? extends
Publisher<? extends R>>
mapper;
MonoFlatMapMany(
Mono<? extends T>
source,
Function<? super T, ? extends
Publisher<? extends R>>
mapper) {
super(
source);
this.
mapper =
mapper;
}
@
Override
public void
subscribe(
CoreSubscriber<? super R>
actual) {
if (
FluxFlatMap.
trySubscribeScalarMap(
source,
actual,
mapper, false)) {
return;
}
source.
subscribe(new
FlatMapManyMain<T, R>(
actual,
mapper));
}
static final class
FlatMapManyMain<T, R> implements
InnerOperator<T, R> {
final
CoreSubscriber<? super R>
actual;
final
Function<? super T, ? extends
Publisher<? extends R>>
mapper;
Subscription main;
volatile
Subscription inner;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
FlatMapManyMain,
Subscription>
INNER =
AtomicReferenceFieldUpdater.
newUpdater(
FlatMapManyMain.class,
Subscription.class,
"inner");
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
FlatMapManyMain>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
FlatMapManyMain.class, "requested");
boolean
hasValue;
FlatMapManyMain(
CoreSubscriber<? super R>
actual,
Function<? super T, ? extends
Publisher<? extends R>>
mapper) {
this.
actual =
actual;
this.
mapper =
mapper;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
main;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
Scannable.
from(
inner));
}
@
Override
public
CoreSubscriber<? super R>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
Subscription a =
inner;
if (
a != null) {
a.
request(
n);
}
else {
if (
Operators.
validate(
n)) {
Operators.
addCap(
REQUESTED, this,
n);
a =
inner;
if (
a != null) {
n =
REQUESTED.
getAndSet(this, 0L);
if (
n != 0L) {
a.
request(
n);
}
}
}
}
}
@
Override
public void
cancel() {
main.
cancel();
Operators.
terminate(
INNER, this);
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
main,
s)) {
this.
main =
s;
actual.
onSubscribe(this);
s.
request(
Long.
MAX_VALUE);
}
}
void
onSubscribeInner(
Subscription s) {
if (
Operators.
setOnce(
INNER, this,
s)) {
long
r =
REQUESTED.
getAndSet(this, 0L);
if (
r != 0) {
s.
request(
r);
}
}
}
@
SuppressWarnings("unchecked")
@
Override
public void
onNext(T
t) {
hasValue = true;
Publisher<? extends R>
p;
try {
p =
Objects.
requireNonNull(
mapper.
apply(
t),
"The mapper returned a null Publisher.");
}
catch (
Throwable ex) {
actual.
onError(
Operators.
onOperatorError(this,
ex,
t,
actual.
currentContext()));
return;
}
if (
p instanceof
Callable) {
R
v;
try {
v = ((
Callable<R>)
p).
call();
}
catch (
Throwable ex) {
actual.
onError(
Operators.
onOperatorError(this,
ex,
t,
actual.
currentContext()));
return;
}
if (
v == null) {
actual.
onComplete();
}
else {
onSubscribeInner(
Operators.
scalarSubscription(
actual,
v));
}
return;
}
p.
subscribe(new
FlatMapManyInner<>(this,
actual));
}
@
Override
public void
onError(
Throwable t) {
if (
hasValue) {
Operators.
onErrorDropped(
t,
actual.
currentContext());
return;
}
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (!
hasValue) {
actual.
onComplete();
}
}
}
static final class
FlatMapManyInner<R> implements
InnerConsumer<R> {
final
FlatMapManyMain<?, R>
parent;
final
CoreSubscriber<? super R>
actual;
FlatMapManyInner(
FlatMapManyMain<?, R>
parent,
CoreSubscriber<? super R>
actual) {
this.
parent =
parent;
this.
actual =
actual;
}
@
Override
public
Context currentContext() {
return
actual.
currentContext();
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
parent.
inner;
if (
key ==
Attr.
ACTUAL) return
parent;
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
parent.
requested;
return null;
}
@
Override
public void
onSubscribe(
Subscription s) {
parent.
onSubscribeInner(
s);
}
@
Override
public void
onNext(R
t) {
actual.
onNext(
t);
}
@
Override
public void
onError(
Throwable t) {
actual.
onError(
t);
}
@
Override
public void
onComplete() {
actual.
onComplete();
}
}
}