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package org.glassfish.jersey.media.sse.internal;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ExecutorService;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import javax.ws.rs.sse.OutboundSseEvent;
import javax.ws.rs.sse.Sse;
import javax.ws.rs.sse.SseBroadcaster;
import javax.ws.rs.sse.SseEventSink;
import org.glassfish.jersey.internal.jsr166.Flow;
import org.glassfish.jersey.internal.util.JerseyPublisher;
import org.glassfish.jersey.media.sse.LocalizationMessages;
/**
* Used for broadcasting SSE to multiple {@link javax.ws.rs.sse.SseEventSink} instances.
* <p>
* JAX-RS 2.1 {@link SseBroadcaster} implementation.
*
* @author Adam Lindenthal (adam.lindenthal at oracle.com)
*/
class JerseySseBroadcaster extends JerseyPublisher<OutboundSseEvent> implements SseBroadcaster {
/**
* Callbacks notified when {@code SseBroadcaster} is being closed.
*/
private final CopyOnWriteArrayList<Consumer<SseEventSink>> onCloseListeners;
/**
* Callbacks notified when error occurs.
*/
private final CopyOnWriteArrayList<BiConsumer<SseEventSink, Throwable>> onExceptionListeners;
/**
* Package-private constructor.
* <p>
* The broadcaster instance should be obtained by calling {@link Sse#newBroadcaster()}, not directly.
*/
JerseySseBroadcaster() {
onExceptionListeners = new CopyOnWriteArrayList<>();
onCloseListeners = new CopyOnWriteArrayList<>();
}
/**
* Package-private constructor.
* <p>
* The broadcaster instance should be obtained by calling {@link Sse#newBroadcaster()}, not directly.
*
* @param executorService {@code ExecutorService} the executor to use for async delivery,
* supporting creation of at least one independent thread
*/
JerseySseBroadcaster(final ExecutorService executorService) {
super(executorService);
onExceptionListeners = new CopyOnWriteArrayList<>();
onCloseListeners = new CopyOnWriteArrayList<>();
}
@Override
public void register(SseEventSink sseEventSink) {
super.subscribe(new SseEventSinkWrapper(sseEventSink));
}
@Override
public void onError(BiConsumer<SseEventSink, Throwable> onError) {
if (onError == null) {
throw new IllegalArgumentException(LocalizationMessages.PARAM_NULL("onError"));
}
onExceptionListeners.add(onError);
}
@Override
public void onClose(Consumer<SseEventSink> onClose) {
if (onClose == null) {
throw new IllegalArgumentException(LocalizationMessages.PARAM_NULL("onClose"));
}
onCloseListeners.add(onClose);
}
@Override
public CompletionStage<?> broadcast(final OutboundSseEvent event) {
if (event == null) {
throw new IllegalArgumentException(LocalizationMessages.PARAM_NULL("event"));
}
publish(event);
// TODO JAX-RS 2.1
return null;
}
private void notifyOnCompleteHandlers(Flow.Subscriber<? super OutboundSseEvent> subscriber) {
if (subscriber instanceof SseEventSinkWrapper) {
onCloseListeners.forEach((listener) -> listener.accept(((SseEventSinkWrapper) subscriber).sseEventSink));
}
}
private void notifyOnErrorCallbacks(final Flow.Subscriber<? super OutboundSseEvent> subscriber, final Throwable throwable) {
if (subscriber instanceof SseEventSinkWrapper) {
onExceptionListeners.forEach(
(listener) -> listener.accept(((SseEventSinkWrapper) subscriber).sseEventSink, throwable));
}
}
private class SseEventSinkWrapper implements Flow.Subscriber<OutboundSseEvent> {
private final SseEventSink sseEventSink;
SseEventSinkWrapper(SseEventSink sseEventSink) {
this.sseEventSink = sseEventSink;
}
@Override
public void onSubscribe(final Flow.Subscription subscription) {
// TODO JAX-RS 2.1
subscription.request(Long.MAX_VALUE);
}
@Override
public void onNext(final OutboundSseEvent item) {
sseEventSink.send(item);
}
@Override
public void onError(final Throwable throwable) {
// TODO JAX-RS 2.1
sseEventSink.close();
notifyOnErrorCallbacks(this, throwable);
}
@Override
public void onComplete() {
// TODO JAX-RS 2.1
sseEventSink.close();
notifyOnCompleteHandlers(this);
}
}
}