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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) 2019-2021 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.function.Function;
import org.reactivestreams.Publisher;
import org.reactivestreams.Subscriber;
import reactor.core.CorePublisher;
import reactor.core.CoreSubscriber;
import reactor.core.publisher.FluxContextWrite.ContextWriteSubscriber;
import reactor.util.context.Context;
/**
* This {@link Function} wrapper is used by operators like {@link Flux#transform(Function)}
* to implement the context loss detection.
*
*/
class ContextTrackingFunctionWrapper implements Function, CorePublisher> {
static final String CONTEXT_MARKER_PREFIX = "reactor.core.context.marker.";
final Function super Publisher, ? extends Publisher> transformer;
final String marker;
ContextTrackingFunctionWrapper(Function super Publisher, ? extends Publisher> transformer) {
this(transformer, transformer.toString());
}
ContextTrackingFunctionWrapper(
Function super Publisher, ? extends Publisher> transformer,
String marker
) {
this.transformer = transformer;
this.marker = marker;
}
@Override
public CorePublisher apply(Publisher source) {
String key = CONTEXT_MARKER_PREFIX + System.identityHashCode(source);
// Wrap source with a logic that will check whether the key is still there and remove it
source = Operators.liftPublisher((p, actual) -> {
Context ctx = actual.currentContext();
if (!ctx.hasKey(key)) {
throw new IllegalStateException("Context loss after applying " + marker);
}
Context newContext = ctx.delete(key);
return new ContextWriteSubscriber<>(actual, newContext);
}).apply(source);
Publisher result = transformer.apply(source);
// It is okay to return `CorePublisher` here since `transform` will use `from()` anyways
return new CorePublisher() {
@Override
public void subscribe(CoreSubscriber super V> actual) {
Context ctx = actual.currentContext().put(key, true);
CoreSubscriber subscriber = new ContextWriteSubscriber<>(actual, ctx);
if (result instanceof CorePublisher) {
((CorePublisher) result).subscribe(subscriber);
}
else {
result.subscribe(subscriber);
}
}
@Override
public void subscribe(Subscriber super V> subscriber) {
subscribe(Operators.toCoreSubscriber(subscriber));
}
};
}
}
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