org.neo4j.driver.internal.shaded.reactor.core.publisher.MonoProcessor Maven / Gradle / Ivy
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/*
* 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.time.Duration;
import java.util.concurrent.CancellationException;
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;
/**
* A {@code MonoProcessor} is a {@link Processor} that is also a {@link Mono}.
*
*
* 
*
*
* Implementations might implements stateful semantics, allowing multiple subscriptions.
* Once a {@link MonoProcessor} has been resolved, implementations may also replay cached signals to newer subscribers.
*
* Despite having default implementations, most methods should be reimplemented with meaningful semantics relevant to
* concrete child classes.
*
* @param the type of the value that will be made available
*
* @author Stephane Maldini
* @deprecated Processors will be removed in 3.5. Prefer using {@link Sinks.One} or {@link Sinks.Empty} instead,
* or see https://github.com/reactor/reactor-core/issues/2431 for alternatives
*/
@Deprecated
public abstract class MonoProcessor extends Mono
implements Processor, CoreSubscriber, Disposable,
Subscription,
Scannable {
/**
* Create a {@link MonoProcessor} that will eagerly request 1 on {@link #onSubscribe(Subscription)}, cache and emit
* the eventual result for 1 or N subscribers.
*
* @param type of the expected value
*
* @return A {@link MonoProcessor}.
* @deprecated Use {@link Sinks#one()}, to be removed in 3.5
*/
@Deprecated
public static MonoProcessor create() {
return new NextProcessor<>(null);
}
/**
* @deprecated the {@link MonoProcessor} will cease to implement {@link Subscription} in 3.5
*/
@Override
@Deprecated
public void cancel() {
}
/**
* Indicates whether this {@code MonoProcessor} has been interrupted via cancellation.
*
* @return {@code true} if this {@code MonoProcessor} is cancelled, {@code false}
* otherwise.
* @deprecated the {@link MonoProcessor} will cease to implement {@link Subscription} and this method will be removed in 3.5
*/
@Deprecated
public boolean isCancelled() {
return false;
}
/**
* @param n the request amount
* @deprecated the {@link MonoProcessor} will cease to implement {@link Subscription} in 3.5
*/
@Override
@Deprecated
public void request(long n) {
Operators.validate(n);
}
@Override
public void dispose() {
onError(new CancellationException("Disposed"));
}
/**
* Block the calling thread indefinitely, waiting for the completion of this {@code MonoProcessor}. If the
* {@link MonoProcessor} is completed with an error a RuntimeException that wraps the error is thrown.
*
* @return the value of this {@code MonoProcessor}
*/
@Override
@Nullable
public O block() {
return block(null);
}
/**
* Block the calling thread for the specified time, waiting for the completion of this {@code MonoProcessor}. If the
* {@link MonoProcessor} is completed with an error a RuntimeException that wraps the error is thrown.
*
* @param timeout the timeout value as a {@link Duration}
*
* @return the value of this {@code MonoProcessor} or {@code null} if the timeout is reached and the {@code MonoProcessor} has
* not completed
*/
@Override
@Nullable
public O block(@Nullable Duration timeout) {
return peek();
}
/**
* Return the produced {@link Throwable} error if any or null
*
* @return the produced {@link Throwable} error if any or null
*/
@Nullable
public Throwable getError() {
return null;
}
/**
* Indicates whether this {@code MonoProcessor} has been completed with an error.
*
* @return {@code true} if this {@code MonoProcessor} was completed with an error, {@code false} otherwise.
*/
public final boolean isError() {
return getError() != null;
}
/**
* Indicates whether this {@code MonoProcessor} has been successfully completed a value.
*
* @return {@code true} if this {@code MonoProcessor} is successful, {@code false} otherwise.
*/
public final boolean isSuccess() {
return isTerminated() && !isError();
}
/**
* Indicates whether this {@code MonoProcessor} has been terminated by the
* source producer with a success or an error.
*
* @return {@code true} if this {@code MonoProcessor} is successful, {@code false} otherwise.
*/
public boolean isTerminated() {
return false;
}
@Override
public boolean isDisposed() {
return isTerminated() || isCancelled();
}
/**
* Returns the value that completed this {@link MonoProcessor}. Returns {@code null} if the {@link MonoProcessor} has not been completed. If the
* {@link MonoProcessor} is completed with an error a RuntimeException that wraps the error is thrown.
*
* @return the value that completed the {@link MonoProcessor}, or {@code null} if it has not been completed
*
* @throws RuntimeException if the {@link MonoProcessor} was completed with an error
* @deprecated this method is discouraged, consider peeking into a MonoProcessor by {@link Mono#toFuture() turning it into a CompletableFuture}
*/
@Nullable
@Deprecated
public O peek() {
return null;
}
@Override
public Context currentContext() {
InnerProducer[] innerProducersArray =
inners().filter(InnerProducer.class::isInstance)
.map(InnerProducer.class::cast)
.toArray(InnerProducer[]::new);
return Operators.multiSubscribersContext(innerProducersArray);
}
@Override
@Nullable
public Object scanUnsafe(Attr key) {
//touch guard
boolean t = isTerminated();
if (key == Attr.TERMINATED) return t;
if (key == Attr.ERROR) return getError();
if (key == Attr.PREFETCH) return Integer.MAX_VALUE;
if (key == Attr.CANCELLED) return isCancelled();
if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC;
return null;
}
/**
* Return the number of active {@link Subscriber} or {@literal -1} if untracked.
*
* @return the number of active {@link Subscriber} or {@literal -1} if untracked
*/
public long downstreamCount() {
return inners().count();
}
/**
* Return true if any {@link Subscriber} is actively subscribed
*
* @return true if any {@link Subscriber} is actively subscribed
*/
public final boolean hasDownstreams() {
return downstreamCount() != 0;
}
@Override
public Stream inners() {
return Stream.empty();
}
}