mirror of
https://github.com/vanitasvitae/Smack.git
synced 2024-09-27 18:19:33 +02:00
98 lines
3.2 KiB
Java
98 lines
3.2 KiB
Java
/**
|
|
*
|
|
* Copyright 2015 Florian Schmaus
|
|
*
|
|
* 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 org.jivesoftware.smack.util;
|
|
|
|
import java.util.Map;
|
|
import java.util.concurrent.ConcurrentHashMap;
|
|
|
|
/**
|
|
* The event manager class is used to perform actions and wait for an event, which is usually caused by the action (or maybe never occurs).
|
|
* <p>
|
|
* Events are distinguished by an unique event key. They can produce an event result, which can simply be null.
|
|
* </p>
|
|
* <p>
|
|
* The action is able to throw an exception.
|
|
* </p>
|
|
*
|
|
* @param <K> the event key.
|
|
* @param <R> the event result.
|
|
* @param <E> the exception which could be thrown by the action.
|
|
*/
|
|
public class EventManger<K, R, E extends Exception> {
|
|
|
|
private final Map<K,Reference<R>> events = new ConcurrentHashMap<>();
|
|
|
|
/**
|
|
* Perform an action and wait for an event.
|
|
* <p>
|
|
* The event is signaled with {@link #signalEvent(Object, Object)}.
|
|
* </p>
|
|
*
|
|
* @param eventKey the event key, must not be null.
|
|
* @param timeout the timeout to wait for the event in milliseconds.
|
|
* @param action the action to perform prior waiting for the event, must not be null.
|
|
* @return the event value, may be null.
|
|
* @throws InterruptedException if interrupted while waiting for the event.
|
|
* @throws E
|
|
*/
|
|
public R performActionAndWaitForEvent(K eventKey, long timeout, Callback<E> action) throws InterruptedException, E {
|
|
final Reference<R> reference = new Reference<>();
|
|
events.put(eventKey, reference);
|
|
try {
|
|
synchronized (reference) {
|
|
action.action();
|
|
reference.wait(timeout);
|
|
}
|
|
return reference.eventResult;
|
|
}
|
|
finally {
|
|
events.remove(eventKey);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Signal an event and the event result.
|
|
* <p>
|
|
* This method will return <code>false</code> if the event was not created with
|
|
* {@link #performActionAndWaitForEvent(Object, long, Callback)}.
|
|
* </p>
|
|
*
|
|
* @param eventKey the event key, must not be null.
|
|
* @param eventResult the event result, may be null.
|
|
* @return true if the event was found and signaled, false otherwise.
|
|
*/
|
|
public boolean signalEvent(K eventKey, R eventResult) {
|
|
final Reference<R> reference = events.get(eventKey);
|
|
if (reference == null) {
|
|
return false;
|
|
}
|
|
reference.eventResult = eventResult;
|
|
synchronized (reference) {
|
|
reference.notifyAll();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
private static class Reference<V> {
|
|
volatile V eventResult;
|
|
}
|
|
|
|
public interface Callback<E extends Exception> {
|
|
public void action() throws E;
|
|
}
|
|
}
|