package org.apache.helix.provisioning.participant;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.
*/
import org.apache.helix.HelixConnection;
import org.apache.helix.api.Resource;
import org.apache.helix.api.Scope;
import org.apache.helix.api.accessor.ClusterAccessor;
import org.apache.helix.api.config.UserConfig;
import org.apache.helix.api.id.ClusterId;
import org.apache.helix.api.id.ParticipantId;
import org.apache.helix.api.id.ResourceId;
import org.apache.helix.api.id.StateModelDefId;
import org.apache.helix.participant.AbstractParticipantService;
import org.apache.helix.provisioning.ServiceConfig;
import org.apache.log4j.Logger;
public abstract class StatelessParticipantService extends AbstractParticipantService {
private static final Logger LOG = Logger.getLogger(StatelessParticipantService.class);
private final String _serviceName;
public StatelessParticipantService(HelixConnection connection, ClusterId clusterId,
ParticipantId participantId, String serviceName) {
super(connection, clusterId, participantId);
_serviceName = serviceName;
}
@Override
protected void init() {
ClusterId clusterId = getClusterId();
ClusterAccessor clusterAccessor = getConnection().createClusterAccessor(clusterId);
ResourceId resourceId = ResourceId.from(_serviceName);
Resource resource = clusterAccessor.readResource(resourceId);
UserConfig userConfig = resource.getUserConfig();
ServiceConfig serviceConfig = new ServiceConfig(Scope.resource(resourceId));
serviceConfig.setSimpleFields(userConfig.getSimpleFields());
serviceConfig.setListFields(userConfig.getListFields());
serviceConfig.setMapFields(userConfig.getMapFields());
LOG.info("Starting service:" + _serviceName + " with configuration:" + serviceConfig);
StatelessServiceStateModelFactory stateModelFactory =
new StatelessServiceStateModelFactory(this);
getParticipant().getStateMachineEngine().registerStateModelFactory(
StateModelDefId.from("StatelessService"), stateModelFactory);
init(serviceConfig);
}
/**
* Get the name of this stateless service
* @return service name
*/
public String getName() {
return _serviceName;
}
/**
* Initialize the service with a configuration
*/
protected abstract void init(ServiceConfig serviceConfig);
/**
* Invoked when this service is instructed to go online
*/
protected abstract void goOnline();
/**
* Invoked when this service is instructed to go offline
*/
protected abstract void goOffine();
}