/*
* Copyright (c) 2011-2018 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.atomic.
AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.
AtomicReferenceFieldUpdater;
import java.util.function.
BiFunction;
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.
Exceptions;
import reactor.core.
Scannable;
import reactor.util.annotation.
Nullable;
import reactor.util.context.
Context;
/**
* Waits for all Mono sources to produce a value or terminate, and if all of them produced
* a value, emit a Tuples of those values; otherwise terminate.
*
* @param <R> the source value types
*/
final class
MonoZip<T, R> extends
Mono<R> implements
SourceProducer<R> {
final boolean
delayError;
final
Publisher<?>[]
sources;
final
Iterable<? extends
Publisher<?>>
sourcesIterable;
final
Function<? super
Object[], ? extends R>
zipper;
@
SuppressWarnings("unchecked")
<U>
MonoZip(boolean
delayError,
Publisher<? extends T>
p1,
Publisher<? extends U>
p2,
BiFunction<? super T, ? super U, ? extends R>
zipper2) {
this(
delayError,
new
FluxZip.
PairwiseZipper<>(new
BiFunction[]{
Objects.
requireNonNull(
zipper2, "zipper2")}),
Objects.
requireNonNull(
p1, "p1"),
Objects.
requireNonNull(
p2, "p2"));
}
MonoZip(boolean
delayError,
Function<? super
Object[], ? extends R>
zipper,
Publisher<?>...
sources) {
this.
delayError =
delayError;
this.
zipper =
Objects.
requireNonNull(
zipper, "zipper");
this.
sources =
Objects.
requireNonNull(
sources, "sources");
this.
sourcesIterable = null;
}
MonoZip(boolean
delayError,
Function<? super
Object[], ? extends R>
zipper,
Iterable<? extends
Publisher<?>>
sourcesIterable) {
this.
delayError =
delayError;
this.
zipper =
Objects.
requireNonNull(
zipper, "zipper");
this.
sources = null;
this.
sourcesIterable =
Objects.
requireNonNull(
sourcesIterable, "sourcesIterable");
}
@
SuppressWarnings("unchecked")
@
Nullable
Mono<R>
zipAdditionalSource(
Publisher source,
BiFunction zipper) {
Publisher[]
oldSources =
sources;
if (
oldSources != null && this.
zipper instanceof
FluxZip.
PairwiseZipper) {
int
oldLen =
oldSources.length;
Publisher<?>[]
newSources = new
Publisher[
oldLen + 1];
System.
arraycopy(
oldSources, 0,
newSources, 0,
oldLen);
newSources[
oldLen] =
source;
Function<
Object[], R>
z =
((
FluxZip.
PairwiseZipper<R>) this.
zipper).
then(
zipper);
return new
MonoZip<>(
delayError,
z,
newSources);
}
return null;
}
@
SuppressWarnings("unchecked")
@
Override
public void
subscribe(
CoreSubscriber<? super R>
actual) {
Publisher<?>[]
a;
int
n = 0;
if (
sources != null) {
a =
sources;
n =
a.length;
}
else {
a = new
Publisher[8];
for (
Publisher<?>
m :
sourcesIterable) {
if (
n ==
a.length) {
Publisher<?>[]
b = new
Publisher[
n + (
n >> 2)];
System.
arraycopy(
a, 0,
b, 0,
n);
a =
b;
}
a[
n++] =
m;
}
}
if (
n == 0) {
Operators.
complete(
actual);
return;
}
ZipCoordinator<R>
parent = new
ZipCoordinator<>(
actual,
n,
delayError,
zipper);
actual.
onSubscribe(
parent);
ZipInner<R>[]
subs =
parent.
subscribers;
for (int
i = 0;
i <
n;
i++) {
a[
i].
subscribe(
subs[
i]);
}
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
DELAY_ERROR) return
delayError;
return null;
}
static final class
ZipCoordinator<R> extends
Operators.
MonoSubscriber<
Object, R> {
final
ZipInner<R>[]
subscribers;
final boolean
delayError;
final
Function<? super
Object[], ? extends R>
zipper;
volatile int
done;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
ZipCoordinator>
DONE =
AtomicIntegerFieldUpdater.
newUpdater(
ZipCoordinator.class, "done");
@
SuppressWarnings("unchecked")
ZipCoordinator(
CoreSubscriber<? super R>
subscriber,
int
n,
boolean
delayError,
Function<? super
Object[], ? extends R>
zipper) {
super(
subscriber);
this.
delayError =
delayError;
this.
zipper =
zipper;
subscribers = new
ZipInner[
n];
for (int
i = 0;
i <
n;
i++) {
subscribers[
i] = new
ZipInner<>(this);
}
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) {
return
done ==
subscribers.length;
}
if (
key ==
Attr.
BUFFERED) {
return
subscribers.length;
}
if (
key ==
Attr.
DELAY_ERROR) {
return
delayError;
}
return super.scanUnsafe(
key);
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
subscribers);
}
@
SuppressWarnings("unchecked")
void
signal() {
ZipInner<R>[]
a =
subscribers;
int
n =
a.length;
if (
DONE.
incrementAndGet(this) !=
n) {
return;
}
Object[]
o = new
Object[
n];
Throwable error = null;
Throwable compositeError = null;
boolean
hasEmpty = false;
for (int
i = 0;
i <
a.length;
i++) {
ZipInner<R>
m =
a[
i];
Object v =
m.
value;
if (
v != null) {
o[
i] =
v;
}
else {
Throwable e =
m.
error;
if (
e != null) {
if (
compositeError != null) {
//this is ok as the composite created below is never a singleton
compositeError.
addSuppressed(
e);
}
else if (
error != null) {
compositeError =
Exceptions.
multiple(
error,
e);
}
else {
error =
e;
}
}
else {
hasEmpty = true;
}
}
}
if (
compositeError != null) {
actual.
onError(
compositeError);
}
else if (
error != null) {
actual.
onError(
error);
}
else if (
hasEmpty) {
actual.
onComplete();
}
else {
R
r;
try {
r =
Objects.
requireNonNull(
zipper.
apply(
o),
"zipper produced a null value");
}
catch (
Throwable t) {
actual.
onError(
Operators.
onOperatorError(null,
t,
o,
actual.
currentContext()));
return;
}
complete(
r);
}
}
@
Override
public void
cancel() {
if (!
isCancelled()) {
super.cancel();
for (
ZipInner<R>
ms :
subscribers) {
ms.
cancel();
}
}
}
void
cancelExcept(
ZipInner<R>
source) {
if (!
isCancelled()) {
super.cancel();
for (
ZipInner<R>
ms :
subscribers) {
if(
ms !=
source) {
ms.
cancel();
}
}
}
}
}
static final class
ZipInner<R> implements
InnerConsumer<
Object> {
final
ZipCoordinator<R>
parent;
volatile
Subscription s;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
ZipInner,
Subscription>
S =
AtomicReferenceFieldUpdater.
newUpdater(
ZipInner.class,
Subscription.class,
"s");
Object value;
Throwable error;
ZipInner(
ZipCoordinator<R>
parent) {
this.
parent =
parent;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
CANCELLED) {
return
s ==
Operators.
cancelledSubscription();
}
if (
key ==
Attr.
PARENT) {
return
s;
}
if (
key ==
Attr.
ACTUAL) {
return
parent;
}
if (
key ==
Attr.
ERROR) {
return
error;
}
return null;
}
@
Override
public
Context currentContext() {
return
parent.
currentContext();
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
setOnce(
S, this,
s)) {
s.
request(
Long.
MAX_VALUE);
}
else {
s.
cancel();
}
}
@
Override
public void
onNext(
Object t) {
if (
value == null) {
value =
t;
parent.
signal();
}
}
@
Override
public void
onError(
Throwable t) {
error =
t;
if (
parent.
delayError) {
parent.
signal();
}
else {
int
n =
parent.
subscribers.length;
if (
ZipCoordinator.
DONE.
getAndSet(
parent,
n) !=
n) {
parent.
cancelExcept(this);
parent.
actual.
onError(
t);
}
}
}
@
Override
public void
onComplete() {
if (
value == null) {
if (
parent.
delayError) {
parent.
signal();
}
else {
int
n =
parent.
subscribers.length;
if (
ZipCoordinator.
DONE.
getAndSet(
parent,
n) !=
n) {
parent.
cancelExcept(this);
parent.
actual.
onComplete();
}
}
}
}
void
cancel() {
Operators.
terminate(
S, this);
}
}
}