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Easy Redis Java client and Real-Time Data Platform. Valkey compatible. Sync/Async/RxJava3/Reactive API. Client side caching. Over 50 Redis based Java objects and services: JCache API, Apache Tomcat, Hibernate, Spring, Set, Multimap, SortedSet, Map, List, Queue, Deque, Semaphore, Lock, AtomicLong, Map Reduce, Bloom filter, Scheduler, RPC
/*
* Copyright (c) 2016-2021 VMware Inc. or its affiliates, 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
*
* https://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.function.BiFunction;
import java.util.function.Supplier;
import org.reactivestreams.Subscription;
import reactor.core.CoreSubscriber;
import reactor.util.annotation.Nullable;
import static reactor.core.Scannable.Attr.RUN_STYLE;
import static reactor.core.Scannable.Attr.RunStyle.SYNC;
/**
* Aggregates the source values with the help of an accumulator function
* and emits the intermediate results.
*
* The accumulation works as follows:
*
* result[0] = initialValue;
* result[1] = accumulator(result[0], source[0])
* result[2] = accumulator(result[1], source[1])
* result[3] = accumulator(result[2], source[2])
* ...
*
*
* @param the source value type
* @param the aggregate type
*
* @see Reactive-Streams-Commons
*/
final class FluxScanSeed extends InternalFluxOperator {
final BiFunction accumulator;
final Supplier initialSupplier;
FluxScanSeed(Flux extends T> source,
Supplier initialSupplier,
BiFunction accumulator) {
super(source);
this.accumulator = Objects.requireNonNull(accumulator, "accumulator");
this.initialSupplier = Objects.requireNonNull(initialSupplier, "initialSupplier");
}
@Override
public CoreSubscriber super T> subscribeOrReturn(CoreSubscriber super R> actual) {
ScanSeedCoordinator coordinator =
new ScanSeedCoordinator<>(actual, source, accumulator, initialSupplier);
actual.onSubscribe(coordinator);
if (!coordinator.isCancelled()) {
coordinator.onComplete();
}
return null;
}
@Override
public Object scanUnsafe(Attr key) {
if (key == RUN_STYLE) return SYNC;
return super.scanUnsafe(key);
}
static final class ScanSeedCoordinator
extends Operators.MultiSubscriptionSubscriber {
final Supplier initialSupplier;
final Flux extends T> source;
final BiFunction accumulator;
volatile int wip;
long produced;
private ScanSeedSubscriber seedSubscriber;
ScanSeedCoordinator(CoreSubscriber super R> actual, Flux extends T> source,
BiFunction accumulator,
Supplier initialSupplier) {
super(actual);
this.source = source;
this.accumulator = accumulator;
this.initialSupplier = initialSupplier;
}
@Override
public void onComplete() {
if (WIP.getAndIncrement(this) == 0) {
do {
if (isCancelled()) {
return;
}
if (null != seedSubscriber && subscription == seedSubscriber) {
actual.onComplete();
return;
}
long c = produced;
if (c != 0L) {
produced = 0L;
produced(c);
}
if (null == seedSubscriber) {
R initialValue;
try {
initialValue = Objects.requireNonNull(initialSupplier.get(),
"The initial value supplied is null");
}
catch (Throwable e) {
onError(Operators.onOperatorError(e, actual.currentContext()));
return;
}
onSubscribe(Operators.scalarSubscription(this, initialValue));
seedSubscriber =
new ScanSeedSubscriber<>(this, accumulator, initialValue);
}
else {
source.subscribe(seedSubscriber);
}
if (isCancelled()) {
return;
}
}
while (WIP.decrementAndGet(this) != 0);
}
}
@Override
public void onNext(R r) {
produced++;
actual.onNext(r);
}
@Override
public Object scanUnsafe(Attr key) {
if (key == RUN_STYLE) return SYNC;
return super.scanUnsafe(key);
}
@SuppressWarnings("rawtypes")
static final AtomicIntegerFieldUpdater WIP =
AtomicIntegerFieldUpdater.newUpdater(ScanSeedCoordinator.class, "wip");
}
static final class ScanSeedSubscriber implements InnerOperator {
final CoreSubscriber super R> actual;
final BiFunction accumulator;
Subscription s;
R value;
boolean done;
ScanSeedSubscriber(CoreSubscriber super R> actual,
BiFunction accumulator,
R initialValue) {
this.actual = actual;
this.accumulator = accumulator;
this.value = initialValue;
}
@Override
public CoreSubscriber super R> actual() {
return actual;
}
@Override
public void cancel() {
s.cancel();
}
@Override
public void onComplete() {
if (done) {
return;
}
done = true;
value = null;
actual.onComplete();
}
@Override
public void onError(Throwable t) {
if (done) {
Operators.onErrorDropped(t, actual.currentContext());
return;
}
done = true;
value = null;
actual.onError(t);
}
@Override
public void onNext(T t) {
if (done) {
Operators.onNextDropped(t, actual.currentContext());
return;
}
R r = value;
try {
r = Objects.requireNonNull(accumulator.apply(r, t),
"The accumulator returned a null value");
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e, t, actual.currentContext()));
return;
}
actual.onNext(r);
value = r;
}
@Override
public void onSubscribe(Subscription s) {
if (Operators.validate(this.s, s)) {
this.s = s;
actual.onSubscribe(this);
}
}
@Override
public void request(long n) {
s.request(n);
}
@Override
@Nullable
public Object scanUnsafe(Attr key) {
if (key == Attr.PARENT) {
return s;
}
if (key == Attr.TERMINATED) {
return done;
}
if (key == RUN_STYLE) {
return SYNC;
}
return InnerOperator.super.scanUnsafe(key);
}
}
}
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