/*
* 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.
AbstractQueue;
import java.util.
Iterator;
import java.util.
Objects;
import java.util.concurrent.atomic.
AtomicLongFieldUpdater;
import java.util.function.
BooleanSupplier;
import java.util.function.
Function;
import java.util.function.
Supplier;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.util.annotation.
Nullable;
/**
* Maps the values of the source publisher one-on-one via a mapper function.
*
* @param <T> the source value type
* @param <R> the result value type
* @author Stephane Maldini
*/
final class
FluxMapSignal<T, R> extends
FluxOperator<T, R> {
final
Function<? super T, ? extends R>
mapperNext;
final
Function<? super
Throwable, ? extends R>
mapperError;
final
Supplier<? extends R>
mapperComplete;
/**
* Constructs a FluxMapSignal instance with the given source and mappers.
*
* @param source the source Publisher instance
* @param mapperNext the next mapper function
* @param mapperError the error mapper function
* @param mapperComplete the complete mapper function
*
* @throws NullPointerException if either {@code source} is null or all {@code mapper} are null.
*/
FluxMapSignal(
Flux<? extends T>
source,
@
Nullable Function<? super T, ? extends R>
mapperNext,
@
Nullable Function<? super
Throwable, ? extends R>
mapperError,
@
Nullable Supplier<? extends R>
mapperComplete) {
super(
source);
if(
mapperNext == null &&
mapperError == null &&
mapperComplete == null){
throw new
IllegalArgumentException("Map Signal needs at least one valid mapper");
}
this.
mapperNext =
mapperNext;
this.
mapperError =
mapperError;
this.
mapperComplete =
mapperComplete;
}
@
Override
public void
subscribe(
CoreSubscriber<? super R>
actual) {
source.
subscribe(new
FluxMapSignalSubscriber<>(
actual,
mapperNext,
mapperError,
mapperComplete));
}
static final class
FluxMapSignalSubscriber<T, R>
extends
AbstractQueue<R>
implements
InnerOperator<T, R>,
BooleanSupplier {
final
CoreSubscriber<? super R>
actual;
final
Function<? super T, ? extends R>
mapperNext;
final
Function<? super
Throwable, ? extends R>
mapperError;
final
Supplier<? extends R>
mapperComplete;
boolean
done;
Subscription s;
R
value;
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
FluxMapSignalSubscriber>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
FluxMapSignalSubscriber.class, "requested");
volatile boolean
cancelled;
long
produced;
FluxMapSignalSubscriber(
CoreSubscriber<? super R>
actual,
@
Nullable Function<? super T, ? extends R>
mapperNext,
@
Nullable Function<? super
Throwable, ? extends R>
mapperError,
@
Nullable Supplier<? extends R>
mapperComplete) {
this.
actual =
actual;
this.
mapperNext =
mapperNext;
this.
mapperError =
mapperError;
this.
mapperComplete =
mapperComplete;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
if (
mapperNext == null) {
s.
request(
Long.
MAX_VALUE);
}
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t,
actual.
currentContext());
return;
}
if (
mapperNext == null) {
return;
}
R
v;
try {
v =
Objects.
requireNonNull(
mapperNext.
apply(
t),
"The mapper returned a null value.");
}
catch (
Throwable e) {
done = true;
actual.
onError(
Operators.
onOperatorError(
s,
e,
t,
actual.
currentContext()));
return;
}
produced++;
actual.
onNext(
v);
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t,
actual.
currentContext());
return;
}
done = true;
if(
mapperError == null){
actual.
onError(
t);
return;
}
R
v;
try {
v =
Objects.
requireNonNull(
mapperError.
apply(
t),
"The mapper returned a null value.");
}
catch (
Throwable e) {
done = true;
actual.
onError(
Operators.
onOperatorError(
s,
e,
t,
actual.
currentContext()));
return;
}
value =
v;
long
p =
produced;
if (
p != 0L) {
Operators.
addCap(
REQUESTED, this, -
p);
}
DrainUtils.
postComplete(
actual, this,
REQUESTED, this, this);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
if(
mapperComplete == null){
actual.
onComplete();
return;
}
R
v;
try {
v =
Objects.
requireNonNull(
mapperComplete.
get(),
"The mapper returned a null value.");
}
catch (
Throwable e) {
done = true;
actual.
onError(
Operators.
onOperatorError(
s,
e,
actual.
currentContext()));
return;
}
value =
v;
long
p =
produced;
if (
p != 0L) {
Operators.
addCap(
REQUESTED, this, -
p);
}
DrainUtils.
postComplete(
actual, this,
REQUESTED, this, this);
}
@
Override
public
CoreSubscriber<? super R>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
if (!
DrainUtils.
postCompleteRequest(
n,
actual, this,
REQUESTED, this, this)) {
s.
request(
n);
}
}
}
@
Override
public boolean
offer(R
e) {
throw new
UnsupportedOperationException();
}
@
Override
@
Nullable
public R
poll() {
R
v =
value;
if (
v != null) {
value = null;
return
v;
}
return null;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
TERMINATED) return
done;
if (
key ==
Attr.
CANCELLED) return
getAsBoolean();
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
requested;
if (
key ==
Attr.
BUFFERED) return
size();
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
@
Nullable
public R
peek() {
return
value;
}
@
Override
public boolean
getAsBoolean() {
return
cancelled;
}
@
Override
public void
cancel() {
cancelled = true;
s.
cancel();
}
@
Override
public
Iterator<R>
iterator() {
throw new
UnsupportedOperationException();
}
@
Override
public int
size() {
return
value == null ? 0 : 1;
}
}
}