/*
* 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.atomic.
AtomicLongFieldUpdater;
import org.reactivestreams.
Subscriber;
import reactor.core.
CoreSubscriber;
import reactor.core.
Fuseable;
import reactor.util.annotation.
Nullable;
/**
* Emits the contents of a wrapped (shared) array.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxArray<T> extends
Flux<T> implements
Fuseable,
SourceProducer<T> {
final T[]
array;
@
SafeVarargs
public
FluxArray(T...
array) {
this.
array =
Objects.
requireNonNull(
array, "array");
}
@
SuppressWarnings("unchecked")
public static <T> void
subscribe(
CoreSubscriber<? super T>
s, T[]
array) {
if (
array.length == 0) {
Operators.
complete(
s);
return;
}
if (
s instanceof
ConditionalSubscriber) {
s.
onSubscribe(new
ArrayConditionalSubscription<>((
ConditionalSubscriber<? super T>)
s,
array));
}
else {
s.
onSubscribe(new
ArraySubscription<>(
s,
array));
}
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
subscribe(
actual,
array);
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
BUFFERED) return
array.length;
return null;
}
static final class
ArraySubscription<T>
implements
InnerProducer<T>,
SynchronousSubscription<T> {
final
CoreSubscriber<? super T>
actual;
final T[]
array;
int
index;
volatile boolean
cancelled;
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
ArraySubscription>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
ArraySubscription.class, "requested");
ArraySubscription(
CoreSubscriber<? super T>
actual, T[]
array) {
this.
actual =
actual;
this.
array =
array;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
if (
Operators.
addCap(
REQUESTED, this,
n) == 0) {
if (
n ==
Long.
MAX_VALUE) {
fastPath();
}
else {
slowPath(
n);
}
}
}
}
void
slowPath(long
n) {
final T[]
a =
array;
final int
len =
a.length;
final
Subscriber<? super T>
s =
actual;
int
i =
index;
int
e = 0;
for (; ; ) {
if (
cancelled) {
return;
}
while (
i !=
len &&
e !=
n) {
T
t =
a[
i];
if (
t == null) {
s.
onError(new
NullPointerException("The " +
i + "th array element was null"));
return;
}
s.
onNext(
t);
if (
cancelled) {
return;
}
i++;
e++;
}
if (
i ==
len) {
s.
onComplete();
return;
}
n =
requested;
if (
n ==
e) {
index =
i;
n =
REQUESTED.
addAndGet(this, -
e);
if (
n == 0) {
return;
}
e = 0;
}
}
}
void
fastPath() {
final T[]
a =
array;
final int
len =
a.length;
final
Subscriber<? super T>
s =
actual;
for (int
i =
index;
i !=
len;
i++) {
if (
cancelled) {
return;
}
T
t =
a[
i];
if (
t == null) {
s.
onError(new
NullPointerException("The " +
i + "th array element was null"));
return;
}
s.
onNext(
t);
}
if (
cancelled) {
return;
}
s.
onComplete();
}
@
Override
public void
cancel() {
cancelled = true;
}
@
Override
@
Nullable
public T
poll() {
int
i =
index;
T[]
a =
array;
if (
i !=
a.length) {
T
t =
a[
i];
Objects.
requireNonNull(
t);
index =
i + 1;
return
t;
}
return null;
}
@
Override
public boolean
isEmpty() {
return
index ==
array.length;
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
clear() {
index =
array.length;
}
@
Override
public int
size() {
return
array.length -
index;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) return
isEmpty();
if (
key ==
Attr.
BUFFERED) return
size();
if (
key ==
Attr.
CANCELLED) return
cancelled;
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
requested;
return
InnerProducer.super.scanUnsafe(
key);
}
}
static final class
ArrayConditionalSubscription<T>
implements
InnerProducer<T>,
SynchronousSubscription<T> {
final
ConditionalSubscriber<? super T>
actual;
final T[]
array;
int
index;
volatile boolean
cancelled;
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
ArrayConditionalSubscription>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
ArrayConditionalSubscription.class,
"requested");
ArrayConditionalSubscription(
ConditionalSubscriber<? super T>
actual, T[]
array) {
this.
actual =
actual;
this.
array =
array;
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
if (
Operators.
addCap(
REQUESTED, this,
n) == 0) {
if (
n ==
Long.
MAX_VALUE) {
fastPath();
}
else {
slowPath(
n);
}
}
}
}
void
slowPath(long
n) {
final T[]
a =
array;
final int
len =
a.length;
final
ConditionalSubscriber<? super T>
s =
actual;
int
i =
index;
int
e = 0;
for (; ; ) {
if (
cancelled) {
return;
}
while (
i !=
len &&
e !=
n) {
T
t =
a[
i];
if (
t == null) {
s.
onError(new
NullPointerException("The " +
i + "th array element was null"));
return;
}
boolean
b =
s.
tryOnNext(
t);
if (
cancelled) {
return;
}
i++;
if (
b) {
e++;
}
}
if (
i ==
len) {
s.
onComplete();
return;
}
n =
requested;
if (
n ==
e) {
index =
i;
n =
REQUESTED.
addAndGet(this, -
e);
if (
n == 0) {
return;
}
e = 0;
}
}
}
void
fastPath() {
final T[]
a =
array;
final int
len =
a.length;
final
Subscriber<? super T>
s =
actual;
for (int
i =
index;
i !=
len;
i++) {
if (
cancelled) {
return;
}
T
t =
a[
i];
if (
t == null) {
s.
onError(new
NullPointerException("The " +
i + "th array element was null"));
return;
}
s.
onNext(
t);
}
if (
cancelled) {
return;
}
s.
onComplete();
}
@
Override
public void
cancel() {
cancelled = true;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) return
isEmpty();
if (
key ==
Attr.
BUFFERED) return
size();
if (
key ==
Attr.
CANCELLED) return
cancelled;
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
requested;
return
InnerProducer.super.scanUnsafe(
key);
}
@
Override
@
Nullable
public T
poll() {
int
i =
index;
T[]
a =
array;
if (
i !=
a.length) {
T
t =
Objects.
requireNonNull(
a[
i], "Array returned null value");
index =
i + 1;
return
t;
}
return null;
}
@
Override
public boolean
isEmpty() {
return
index ==
array.length;
}
@
Override
public void
clear() {
index =
array.length;
}
@
Override
public int
size() {
return
array.length -
index;
}
}
}