/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.elasticsearch.common.component;
import org.elasticsearch.common.settings.Settings;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
public abstract class AbstractLifecycleComponent extends AbstractComponent implements LifecycleComponent {
protected final Lifecycle lifecycle = new Lifecycle();
private final List<LifecycleListener> listeners = new CopyOnWriteArrayList<>();
protected AbstractLifecycleComponent(Settings settings) {
super(settings);
}
protected AbstractLifecycleComponent(Settings settings, Class customClass) {
super(settings, customClass);
}
@Override
public Lifecycle.State lifecycleState() {
return this.lifecycle.state();
}
@Override
public void addLifecycleListener(LifecycleListener listener) {
listeners.add(listener);
}
@Override
public void removeLifecycleListener(LifecycleListener listener) {
listeners.remove(listener);
}
@SuppressWarnings({"unchecked"})
@Override
public void start() {
if (!lifecycle.canMoveToStarted()) {
return;
}
for (LifecycleListener listener : listeners) {
listener.beforeStart();
}
doStart();
lifecycle.moveToStarted();
for (LifecycleListener listener : listeners) {
listener.afterStart();
}
}
protected abstract void doStart();
@SuppressWarnings({"unchecked"})
@Override
public void stop() {
if (!lifecycle.canMoveToStopped()) {
return;
}
for (LifecycleListener listener : listeners) {
listener.beforeStop();
}
lifecycle.moveToStopped();
doStop();
for (LifecycleListener listener : listeners) {
listener.afterStop();
}
}
protected abstract void doStop();
@Override
public void close() {
if (lifecycle.started()) {
stop();
}
if (!lifecycle.canMoveToClosed()) {
return;
}
for (LifecycleListener listener : listeners) {
listener.beforeClose();
}
lifecycle.moveToClosed();
try {
doClose();
} catch (IOException e) {
// TODO: we need to separate out closing (ie shutting down) services, vs releasing runtime transient
// structures. Shutting down services should use IOUtils.close
logger.warn("failed to close " + getClass().getName(), e);
}
for (LifecycleListener listener : listeners) {
listener.afterClose();
}
}
protected abstract void doClose() throws IOException;
}