reactor.rx.stream.LiftStream Maven / Gradle / Ivy
The newest version!
/*
* Copyright (c) 2011-2015 Pivotal Software Inc., 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.rx.stream;
import org.reactivestreams.Subscriber;
import reactor.Environment;
import reactor.core.Dispatcher;
import reactor.core.support.Exceptions;
import reactor.fn.Supplier;
import reactor.rx.Stream;
import reactor.rx.action.Action;
import reactor.rx.action.CompositeAction;
/**
* A Stream wrapper that defers a parent stream subscription to the child action subscribe() call.
*
* @author Stephane Maldini
* @since 2.0
*/
public class LiftStream extends Stream {
private final Stream producer;
private final Supplier> child;
public LiftStream(Stream thiz, Supplier> action) {
this.producer = thiz;
this.child = action;
}
public final Action onLift() {
return child.get();
}
@SuppressWarnings("unchecked")
@Override
public final CompositeAction combine() {
Action action = onLift();
if (action == null) {
throw new IllegalStateException("Cannot combine streams without any lifted action");
}
producer.subscribe(action);
return action.combine();
}
@Override
public long getCapacity() {
return producer.getCapacity();
}
@Override
public Dispatcher getDispatcher() {
return producer.getDispatcher();
}
@Override
public Environment getEnvironment() {
return producer.getEnvironment();
}
@Override
public final void subscribe(Subscriber s) {
try {
Action action = onLift();
action.subscribe(s);
producer.subscribe(action);
} catch (Throwable throwable) {
Exceptions.throwIfFatal(throwable);
s.onError(throwable);
}
}
@Override
public final String toString() {
return "LiftStream{" +
"producer=" + producer.getClass().getSimpleName() +
'}';
}
}