/*
* 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.
Queue;
import java.util.concurrent.atomic.
AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.
AtomicLongFieldUpdater;
import java.util.concurrent.atomic.
AtomicReferenceFieldUpdater;
import java.util.function.
Function;
import java.util.function.
Supplier;
import java.util.stream.
Stream;
import org.reactivestreams.
Publisher;
import org.reactivestreams.
Subscriber;
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;
/**
* Emits the last value from upstream only if there were no newer values emitted
* during the time window provided by a publisher for that particular last value.
*
* @param <T> the source value type
* @param <U> the value type of the duration publisher
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxSampleTimeout<T, U> extends
FluxOperator<T, T> {
final
Function<? super T, ? extends
Publisher<U>>
throttler;
final
Supplier<
Queue<
Object>>
queueSupplier;
FluxSampleTimeout(
Flux<? extends T>
source,
Function<? super T, ? extends
Publisher<U>>
throttler,
Supplier<
Queue<
Object>>
queueSupplier) {
super(
source);
this.
throttler =
Objects.
requireNonNull(
throttler, "throttler");
this.
queueSupplier =
Objects.
requireNonNull(
queueSupplier, "queueSupplier");
}
@
Override
public int
getPrefetch() {
return
Integer.
MAX_VALUE;
}
@
SuppressWarnings({"rawtypes", "unchecked"})
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
Queue<
SampleTimeoutOther<T, U>>
q = (
Queue)
queueSupplier.
get();
SampleTimeoutMain<T, U>
main = new
SampleTimeoutMain<>(
actual,
throttler,
q);
actual.
onSubscribe(
main);
source.
subscribe(
main);
}
static final class
SampleTimeoutMain<T, U>implements
InnerOperator<T, T> {
final
Function<? super T, ? extends
Publisher<U>>
throttler;
final
Queue<
SampleTimeoutOther<T, U>>
queue;
final
CoreSubscriber<? super T>
actual;
final
Context ctx;
volatile
Subscription s;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
SampleTimeoutMain,
Subscription>
S =
AtomicReferenceFieldUpdater.
newUpdater(
SampleTimeoutMain.class,
Subscription.class,
"s");
volatile
Subscription other;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
SampleTimeoutMain,
Subscription>
OTHER =
AtomicReferenceFieldUpdater.
newUpdater(
SampleTimeoutMain.class,
Subscription.class,
"other");
volatile long
requested;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
SampleTimeoutMain>
REQUESTED =
AtomicLongFieldUpdater.
newUpdater(
SampleTimeoutMain.class, "requested");
volatile int
wip;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
SampleTimeoutMain>
WIP =
AtomicIntegerFieldUpdater.
newUpdater(
SampleTimeoutMain.class, "wip");
volatile
Throwable error;
@
SuppressWarnings("rawtypes")
static final
AtomicReferenceFieldUpdater<
SampleTimeoutMain,
Throwable>
ERROR =
AtomicReferenceFieldUpdater.
newUpdater(
SampleTimeoutMain.class,
Throwable.class,
"error");
volatile boolean
done;
volatile boolean
cancelled;
volatile long
index;
@
SuppressWarnings("rawtypes")
static final
AtomicLongFieldUpdater<
SampleTimeoutMain>
INDEX =
AtomicLongFieldUpdater.
newUpdater(
SampleTimeoutMain.class, "index");
SampleTimeoutMain(
CoreSubscriber<? super T>
actual,
Function<? super T, ? extends
Publisher<U>>
throttler,
Queue<
SampleTimeoutOther<T, U>>
queue) {
this.
actual =
actual;
this.
ctx =
actual.
currentContext();
this.
throttler =
throttler;
this.
queue =
queue;
}
@
Override
public
Stream<? extends
Scannable>
inners() {
return
Stream.
of(
Scannable.
from(
other));
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) return
done;
if (
key ==
Attr.
CANCELLED) return
cancelled;
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
ERROR) return
error;
if (
key ==
Attr.
REQUESTED_FROM_DOWNSTREAM) return
requested;
if (
key ==
Attr.
BUFFERED) return
queue.
size();
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
public final
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
if (
Operators.
validate(
n)) {
Operators.
addCap(
REQUESTED, this,
n);
}
}
@
Override
public void
cancel() {
if (!
cancelled) {
cancelled = true;
Operators.
terminate(
S, this);
Operators.
terminate(
OTHER, this);
Operators.
onDiscardQueueWithClear(
queue,
ctx,
SampleTimeoutOther::toStream);
}
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
setOnce(
S, this,
s)) {
s.
request(
Long.
MAX_VALUE);
}
}
@
Override
public void
onNext(T
t) {
long
idx =
INDEX.
incrementAndGet(this);
if (!
Operators.
set(
OTHER, this,
Operators.
emptySubscription())) {
return;
}
Publisher<U>
p;
try {
p =
Objects.
requireNonNull(
throttler.
apply(
t),
"throttler returned a null publisher");
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t,
ctx));
return;
}
SampleTimeoutOther<T, U>
os = new
SampleTimeoutOther<>(this,
t,
idx);
if (
Operators.
replace(
OTHER, this,
os)) {
p.
subscribe(
os);
}
}
void
error(
Throwable t) {
if (
Exceptions.
addThrowable(
ERROR, this,
t)) {
done = true;
drain();
}
else {
Operators.
onErrorDropped(
t,
ctx);
}
}
@
Override
public void
onError(
Throwable t) {
Operators.
terminate(
OTHER, this);
error(
t);
}
@
Override
public void
onComplete() {
Subscription o =
other;
if (
o instanceof
FluxSampleTimeout.
SampleTimeoutOther) {
SampleTimeoutOther<?, ?>
os = (
SampleTimeoutOther<?, ?>)
o;
os.
cancel();
os.
onComplete();
}
done = true;
drain();
}
void
otherNext(
SampleTimeoutOther<T, U>
other) {
queue.
offer(
other);
drain();
}
void
otherError(long
idx,
Throwable e) {
if (
idx ==
index) {
Operators.
terminate(
S, this);
error(
e);
}
else {
Operators.
onErrorDropped(
e,
ctx);
}
}
void
drain() {
if (
WIP.
getAndIncrement(this) != 0) {
return;
}
final
Subscriber<? super T>
a =
actual;
final
Queue<
SampleTimeoutOther<T, U>>
q =
queue;
int
missed = 1;
for (; ; ) {
for (; ; ) {
boolean
d =
done;
SampleTimeoutOther<T, U>
o =
q.
poll();
boolean
empty =
o == null;
if (
checkTerminated(
d,
empty,
a,
q)) {
return;
}
if (
empty) {
break;
}
if (
o.
index ==
index) {
long
r =
requested;
if (
r != 0) {
a.
onNext(
o.
value);
if (
r !=
Long.
MAX_VALUE) {
REQUESTED.
decrementAndGet(this);
}
}
else {
cancel();
Operators.
onDiscardQueueWithClear(
q,
ctx,
SampleTimeoutOther::toStream);
Throwable e =
Exceptions.
failWithOverflow(
"Could not emit value due to lack of requests");
Exceptions.
addThrowable(
ERROR, this,
e);
e =
Exceptions.
terminate(
ERROR, this);
a.
onError(
e);
return;
}
}
}
missed =
WIP.
addAndGet(this, -
missed);
if (
missed == 0) {
break;
}
}
}
boolean
checkTerminated(boolean
d, boolean
empty,
Subscriber<?>
a,
Queue<
SampleTimeoutOther<T, U>>
q) {
if (
cancelled) {
Operators.
onDiscardQueueWithClear(
q,
ctx,
SampleTimeoutOther::toStream);
return true;
}
if (
d) {
Throwable e =
Exceptions.
terminate(
ERROR, this);
if (
e != null &&
e !=
Exceptions.
TERMINATED) {
cancel();
Operators.
onDiscardQueueWithClear(
q,
ctx,
SampleTimeoutOther::toStream);
a.
onError(
e);
return true;
}
else if (
empty) {
a.
onComplete();
return true;
}
}
return false;
}
}
static final class
SampleTimeoutOther<T, U> extends
Operators.
DeferredSubscription
implements
InnerConsumer<U> {
final
SampleTimeoutMain<T, U>
main;
final T
value;
final long
index;
volatile int
once;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
SampleTimeoutOther>
ONCE =
AtomicIntegerFieldUpdater.
newUpdater(
SampleTimeoutOther.class, "once");
SampleTimeoutOther(
SampleTimeoutMain<T, U>
main, T
value, long
index) {
this.
main =
main;
this.
value =
value;
this.
index =
index;
}
@
Override
public
Context currentContext() {
return
main.
currentContext();
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
TERMINATED) return
once == 1;
if (
key ==
Attr.
ACTUAL) return
main;
return super.scanUnsafe(
key);
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
set(
s)) {
s.
request(
Long.
MAX_VALUE);
}
}
@
Override
public void
onNext(U
t) {
if (
ONCE.
compareAndSet(this, 0, 1)) {
cancel();
main.
otherNext(this);
}
}
@
Override
public void
onError(
Throwable t) {
if (
ONCE.
compareAndSet(this, 0, 1)) {
main.
otherError(
index,
t);
}
else {
Operators.
onErrorDropped(
t,
main.
currentContext());
}
}
@
Override
public void
onComplete() {
if (
ONCE.
compareAndSet(this, 0, 1)) {
main.
otherNext(this);
}
}
final
Stream<T>
toStream() {
return
Stream.
of(
value);
}
}
}