org.smallmind.file.ephemeral.watch.EphemeralWatchKey Maven / Gradle / Ivy
/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* .
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
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*/
package org.smallmind.file.ephemeral.watch;
import java.nio.file.NoSuchFileException;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.Watchable;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.LinkedBlockingQueue;
import org.smallmind.file.ephemeral.EphemeralPath;
public class EphemeralWatchKey implements WatchKey {
private final EphemeralWatchService watchService;
private final WatchEvent.Kind[] events;
private final EphemeralPath path;
private final LinkedBlockingQueue> eventQueue = new LinkedBlockingQueue<>();
private boolean valid = true;
private boolean signalled = false;
public EphemeralWatchKey (EphemeralWatchService watchService, WatchEvent.Kind[] events, EphemeralPath path) {
this.watchService = watchService;
this.events = events;
this.path = path;
}
public EphemeralPath getPath () {
return path;
}
@Override
public synchronized boolean isValid () {
return valid && (!watchService.isClosed());
}
public synchronized boolean fire (WatchEvent.Kind firedEvent) {
if (valid) {
for (WatchEvent.Kind event : events) {
if (event.getClass().equals(firedEvent.getClass()) && event.name().equals(firedEvent.name())) {
eventQueue.add(new EphemeralWatchEvent<>(firedEvent, 1, null));
if (!signalled) {
signalled = true;
return true;
} else {
return false;
}
}
}
}
return false;
}
@Override
public List> pollEvents () {
LinkedList> eventList = new LinkedList<>();
WatchEvent event;
while ((event = eventQueue.poll()) != null) {
eventList.add(event);
}
return eventList;
}
@Override
public synchronized boolean reset () {
if (isValid()) {
if (!eventQueue.isEmpty()) {
watchService.requeue(this);
} else {
signalled = false;
}
return true;
} else {
return false;
}
}
@Override
public synchronized void cancel () {
cancel(true);
}
public synchronized void cancel (boolean deregister) {
valid = false;
if (deregister) {
try {
watchService.unregister(this);
} catch (NoSuchFileException noSuchFileException) {
// nothing to do here
}
}
}
@Override
public Watchable watchable () {
return path;
}
}