/*
* 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.
ArrayDeque;
import java.util.
Objects;
import java.util.
Queue;
import java.util.concurrent.atomic.
AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.
AtomicLongFieldUpdater;
import java.util.function.
Supplier;
import java.util.stream.
Stream;
import org.reactivestreams.
Processor;
import org.reactivestreams.
Subscriber;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Disposable;
import reactor.core.
Scannable;
import reactor.util.annotation.
Nullable;
import reactor.util.context.
Context;
/**
* Splits the source sequence into possibly overlapping publishers.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">https://github.com/reactor/reactive-streams-commons</a>
*/
final class
FluxWindow<T> extends
FluxOperator<T,
Flux<T>> {
final int
size;
final int
skip;
final
Supplier<? extends
Queue<T>>
processorQueueSupplier;
final
Supplier<? extends
Queue<
UnicastProcessor<T>>>
overflowQueueSupplier;
FluxWindow(
Flux<? extends T>
source,
int
size,
Supplier<? extends
Queue<T>>
processorQueueSupplier) {
super(
source);
if (
size <= 0) {
throw new
IllegalArgumentException("size > 0 required but it was " +
size);
}
this.
size =
size;
this.
skip =
size;
this.
processorQueueSupplier =
Objects.
requireNonNull(
processorQueueSupplier, "processorQueueSupplier");
this.
overflowQueueSupplier = null; // won't be needed here
}
FluxWindow(
Flux<? extends T>
source,
int
size,
int
skip,
Supplier<? extends
Queue<T>>
processorQueueSupplier,
Supplier<? extends
Queue<
UnicastProcessor<T>>>
overflowQueueSupplier) {
super(
source);
if (
size <= 0) {
throw new
IllegalArgumentException("size > 0 required but it was " +
size);
}
if (
skip <= 0) {
throw new
IllegalArgumentException("skip > 0 required but it was " +
skip);
}
this.
size =
size;
this.
skip =
skip;
this.
processorQueueSupplier =
Objects.
requireNonNull(
processorQueueSupplier, "processorQueueSupplier");
this.
overflowQueueSupplier =
Objects.
requireNonNull(
overflowQueueSupplier, "overflowQueueSupplier");
}
@
Override
public void
subscribe(
CoreSubscriber<? super
Flux<T>>
actual) {
if (
skip ==
size) {
source.
subscribe(new
WindowExactSubscriber<>(
actual,
size,
processorQueueSupplier));
}
else if (
skip >
size) {
source.
subscribe(new
WindowSkipSubscriber<>(
actual,
size,
skip,
processorQueueSupplier));
}
else {
source.
subscribe(new
WindowOverlapSubscriber<>(
actual,
size,
skip,
processorQueueSupplier,
overflowQueueSupplier.
get()));
}
}
static final class
WindowExactSubscriber<T>
implements
Disposable,
InnerOperator<T,
Flux<T>> {
final
CoreSubscriber<? super
Flux<T>>
actual;
final
Supplier<? extends
Queue<T>>
processorQueueSupplier;
final int
size;
volatile int
cancelled;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowExactSubscriber>
CANCELLED =
AtomicIntegerFieldUpdater.
newUpdater(
WindowExactSubscriber.class, "cancelled");
volatile int
windowCount;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowExactSubscriber>
WINDOW_COUNT =
AtomicIntegerFieldUpdater.
newUpdater(
WindowExactSubscriber.class, "windowCount");
int
index;
Subscription s;
UnicastProcessor<T>
window;
boolean
done;
WindowExactSubscriber(
CoreSubscriber<? super
Flux<T>>
actual,
int
size,
Supplier<? extends
Queue<T>>
processorQueueSupplier) {
this.
actual =
actual;
this.
size =
size;
this.
processorQueueSupplier =
processorQueueSupplier;
WINDOW_COUNT.
lazySet(this, 1);
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t,
actual.
currentContext());
return;
}
int
i =
index;
UnicastProcessor<T>
w =
window;
if (
cancelled == 0 &&
i == 0) {
WINDOW_COUNT.
getAndIncrement(this);
w = new
UnicastProcessor<>(
processorQueueSupplier.
get(), this);
window =
w;
actual.
onNext(
w);
}
i++;
w.
onNext(
t);
if (
i ==
size) {
index = 0;
window = null;
w.
onComplete();
}
else {
index =
i;
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t,
actual.
currentContext());
return;
}
done = true;
Processor<T, T>
w =
window;
if (
w != null) {
window = null;
w.
onError(
t);
}
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
Processor<T, T>
w =
window;
if (
w != null) {
window = null;
w.
onComplete();
}
actual.
onComplete();
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
long
u =
Operators.
multiplyCap(
size,
n);
s.
request(
u);
}
}
@
Override
public void
cancel() {
if (
CANCELLED.
compareAndSet(this, 0, 1)) {
dispose();
}
}
@
Override
public void
dispose() {
if (
WINDOW_COUNT.
decrementAndGet(this) == 0) {
s.
cancel();
}
}
@
Override
public
CoreSubscriber<? super
Flux<T>>
actual() {
return
actual;
}
@
Override
public boolean
isDisposed() {
return
cancelled == 1 ||
done;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
CANCELLED) return
cancelled == 1;
if (
key ==
Attr.
CAPACITY) return
size;
if (
key ==
Attr.
TERMINATED) return
done;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
window);
}
}
static final class
WindowSkipSubscriber<T>
implements
Disposable,
InnerOperator<T,
Flux<T>> {
final
CoreSubscriber<? super
Flux<T>>
actual;
final
Context ctx;
final
Supplier<? extends
Queue<T>>
processorQueueSupplier;
final int
size;
final int
skip;
volatile int
cancelled;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowSkipSubscriber>
CANCELLED =
AtomicIntegerFieldUpdater.
newUpdater(
WindowSkipSubscriber.class, "cancelled");
volatile int
windowCount;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowSkipSubscriber>
WINDOW_COUNT =
AtomicIntegerFieldUpdater.
newUpdater(
WindowSkipSubscriber.class, "windowCount");
volatile int
firstRequest;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowSkipSubscriber>
FIRST_REQUEST =
AtomicIntegerFieldUpdater.
newUpdater(
WindowSkipSubscriber.class,
"firstRequest");
int
index;
Subscription s;
UnicastProcessor<T>
window;
boolean
done;
WindowSkipSubscriber(
CoreSubscriber<? super
Flux<T>>
actual,
int
size,
int
skip,
Supplier<? extends
Queue<T>>
processorQueueSupplier) {
this.
actual =
actual;
this.
ctx =
actual.
currentContext();
this.
size =
size;
this.
skip =
skip;
this.
processorQueueSupplier =
processorQueueSupplier;
WINDOW_COUNT.
lazySet(this, 1);
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t,
ctx);
return;
}
int
i =
index;
UnicastProcessor<T>
w =
window;
if (
i == 0) {
WINDOW_COUNT.
getAndIncrement(this);
w = new
UnicastProcessor<>(
processorQueueSupplier.
get(), this);
window =
w;
actual.
onNext(
w);
}
i++;
if (
w != null) {
w.
onNext(
t);
}
else {
Operators.
onDiscard(
t,
ctx);
}
if (
i ==
size) {
window = null;
if (
w != null) {
w.
onComplete();
}
}
if (
i ==
skip) {
index = 0;
}
else {
index =
i;
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t,
ctx);
return;
}
done = true;
Processor<T, T>
w =
window;
if (
w != null) {
window = null;
w.
onError(
t);
}
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
Processor<T, T>
w =
window;
if (
w != null) {
window = null;
w.
onComplete();
}
actual.
onComplete();
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
if (
firstRequest == 0 &&
FIRST_REQUEST.
compareAndSet(this, 0, 1)) {
long
u =
Operators.
multiplyCap(
size,
n);
long
v =
Operators.
multiplyCap(
skip -
size,
n - 1);
long
w =
Operators.
addCap(
u,
v);
s.
request(
w);
}
else {
long
u =
Operators.
multiplyCap(
skip,
n);
s.
request(
u);
}
}
}
@
Override
public void
cancel() {
if (
CANCELLED.
compareAndSet(this, 0, 1)) {
dispose();
}
}
@
Override
public boolean
isDisposed() {
return
cancelled == 1 ||
done;
}
@
Override
public void
dispose() {
if (
WINDOW_COUNT.
decrementAndGet(this) == 0) {
s.
cancel();
}
}
@
Override
public
CoreSubscriber<? super
Flux<T>>
actual() {
return
actual;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
CANCELLED) return
cancelled == 1;
if (
key ==
Attr.
CAPACITY) return
size;
if (
key ==
Attr.
TERMINATED) return
done;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
window);
}
}
static final class
WindowOverlapSubscriber<T> extends
ArrayDeque<
UnicastProcessor<T>>
implements
Disposable,
InnerOperator<T,
Flux<T>> {
final
CoreSubscriber<? super
Flux<T>>
actual;
final
Supplier<? extends
Queue<T>>
processorQueueSupplier;
final
Queue<
UnicastProcessor<T>>
queue;
final int
size;
final int
skip;
volatile int
cancelled;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowOverlapSubscriber>
CANCELLED =
AtomicIntegerFieldUpdater.
newUpdater(
WindowOverlapSubscriber.class,
"cancelled");
volatile int
windowCount;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowOverlapSubscriber>
WINDOW_COUNT =
AtomicIntegerFieldUpdater.
newUpdater(
WindowOverlapSubscriber.class,
"windowCount");
volatile int
firstRequest;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowOverlapSubscriber>
FIRST_REQUEST =
AtomicIntegerFieldUpdater.
newUpdater(
WindowOverlapSubscriber.class,
"firstRequest");
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
WindowOverlapSubscriber>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
WindowOverlapSubscriber.class,
"requested");
volatile int
wip;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
WindowOverlapSubscriber>
WIP =
AtomicIntegerFieldUpdater.
newUpdater(
WindowOverlapSubscriber.class, "wip");
int
index;
int
produced;
Subscription s;
volatile boolean
done;
Throwable error;
WindowOverlapSubscriber(
CoreSubscriber<? super
Flux<T>>
actual,
int
size,
int
skip,
Supplier<? extends
Queue<T>>
processorQueueSupplier,
Queue<
UnicastProcessor<T>>
overflowQueue) {
this.
actual =
actual;
this.
size =
size;
this.
skip =
skip;
this.
processorQueueSupplier =
processorQueueSupplier;
WINDOW_COUNT.
lazySet(this, 1);
this.
queue =
overflowQueue;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t,
actual.
currentContext());
return;
}
int
i =
index;
if (
i == 0) {
if (
cancelled == 0) {
WINDOW_COUNT.
getAndIncrement(this);
UnicastProcessor<T>
w = new
UnicastProcessor<>(
processorQueueSupplier.
get(), this);
offer(
w);
queue.
offer(
w);
drain();
}
}
i++;
for (
Processor<T, T>
w : this) {
w.
onNext(
t);
}
int
p =
produced + 1;
if (
p ==
size) {
produced =
p -
skip;
Processor<T, T>
w =
poll();
if (
w != null) {
w.
onComplete();
}
}
else {
produced =
p;
}
if (
i ==
skip) {
index = 0;
}
else {
index =
i;
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t,
actual.
currentContext());
return;
}
done = true;
for (
Processor<T, T>
w : this) {
w.
onError(
t);
}
clear();
error =
t;
drain();
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
for (
Processor<T, T>
w : this) {
w.
onComplete();
}
clear();
drain();
}
void
drain() {
if (
WIP.
getAndIncrement(this) != 0) {
return;
}
final
Subscriber<? super
Flux<T>>
a =
actual;
final
Queue<
UnicastProcessor<T>>
q =
queue;
int
missed = 1;
for (; ; ) {
long
r =
requested;
long
e = 0;
while (
e !=
r) {
boolean
d =
done;
UnicastProcessor<T>
t =
q.
poll();
boolean
empty =
t == null;
if (
checkTerminated(
d,
empty,
a,
q)) {
return;
}
if (
empty) {
break;
}
a.
onNext(
t);
e++;
}
if (
e ==
r) {
if (
checkTerminated(
done,
q.
isEmpty(),
a,
q)) {
return;
}
}
if (
e != 0L &&
r !=
Long.
MAX_VALUE) {
REQUESTED.
addAndGet(this, -
e);
}
missed =
WIP.
addAndGet(this, -
missed);
if (
missed == 0) {
break;
}
}
}
boolean
checkTerminated(boolean
d, boolean
empty,
Subscriber<?>
a,
Queue<?>
q) {
if (
cancelled == 1) {
q.
clear();
return true;
}
if (
d) {
Throwable e =
error;
if (
e != null) {
q.
clear();
a.
onError(
e);
return true;
}
else if (
empty) {
a.
onComplete();
return true;
}
}
return false;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
Operators.
addCap(
REQUESTED, this,
n);
if (
firstRequest == 0 &&
FIRST_REQUEST.
compareAndSet(this, 0, 1)) {
long
u =
Operators.
multiplyCap(
skip,
n - 1);
long
v =
Operators.
addCap(
size,
u);
s.
request(
v);
}
else {
long
u =
Operators.
multiplyCap(
skip,
n);
s.
request(
u);
}
drain();
}
}
@
Override
public void
cancel() {
if (
CANCELLED.
compareAndSet(this, 0, 1)) {
dispose();
}
}
@
Override
public void
dispose() {
if (
WINDOW_COUNT.
decrementAndGet(this) == 0) {
s.
cancel();
}
}
@
Override
public
CoreSubscriber<? super
Flux<T>>
actual() {
return
actual;
}
@
Override
public boolean
isDisposed() {
return
cancelled == 1 ||
done;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
CANCELLED) return
cancelled == 1;
if (
key ==
Attr.
CAPACITY) return
size;
if (
key ==
Attr.
TERMINATED) return
done;
if (
key ==
Attr.
LARGE_BUFFERED) return (long)
queue.
size() +
size();
if (
key ==
Attr.
BUFFERED) {
long
realBuffered = (long)
queue.
size() +
size();
if (
realBuffered <
Integer.
MAX_VALUE) return (int)
realBuffered;
return
Integer.
MIN_VALUE;
}
if (
key ==
Attr.
ERROR) return
error;
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
requested;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
toArray())
.
map(
Scannable::from);
}
}
}