/*
* Druid - a distributed column store.
* Copyright (C) 2012, 2013 Metamarkets Group Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package io.druid.segment.realtime.firehose;
import com.google.common.base.Optional;
import com.google.common.collect.Maps;
import com.google.inject.Inject;
import com.metamx.common.ISE;
import com.metamx.common.logger.Logger;
import io.druid.curator.discovery.ServiceAnnouncer;
import io.druid.guice.annotations.Self;
import io.druid.server.DruidNode;
import java.util.concurrent.ConcurrentMap;
/**
* Provides a way for the outside world to talk to objects in the indexing service. The {@link #get(String)} method
* allows anyone with a reference to this object to obtain a particular {@link ChatHandler}. An embedded
* {@link ServiceAnnouncer} will be used to advertise handlers on this host.
*/
public class ServiceAnnouncingChatHandlerProvider implements ChatHandlerProvider
{
private static final Logger log = new Logger(ServiceAnnouncingChatHandlerProvider.class);
private final DruidNode node;
private final ServiceAnnouncer serviceAnnouncer;
private final ConcurrentMap<String, ChatHandler> handlers;
@Inject
public ServiceAnnouncingChatHandlerProvider(
@Self DruidNode node,
ServiceAnnouncer serviceAnnouncer
)
{
this.node = node;
this.serviceAnnouncer = serviceAnnouncer;
this.handlers = Maps.newConcurrentMap();
}
@Override
public void register(final String service, ChatHandler handler)
{
final DruidNode node = makeDruidNode(service);
log.info("Registering Eventhandler[%s]", service);
if (handlers.putIfAbsent(service, handler) != null) {
throw new ISE("handler already registered for service[%s]", service);
}
try {
serviceAnnouncer.announce(node);
}
catch (Exception e) {
log.warn(e, "Failed to register service[%s]", service);
handlers.remove(service, handler);
}
}
@Override
public void unregister(final String service)
{
log.info("Unregistering chat handler[%s]", service);
final ChatHandler handler = handlers.get(service);
if (handler == null) {
log.warn("handler[%s] not currently registered, ignoring.", service);
}
try {
serviceAnnouncer.unannounce(makeDruidNode(service));
}
catch (Exception e) {
log.warn(e, "Failed to unregister service[%s]", service);
}
handlers.remove(service, handler);
}
@Override
public Optional<ChatHandler> get(final String key)
{
return Optional.fromNullable(handlers.get(key));
}
private DruidNode makeDruidNode(String key)
{
return new DruidNode(key, node.getHost(), node.getPort());
}
}