/*
* JBoss, Home of Professional Open Source.
* Copyright 2013, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.wildfly.clustering.server.singleton;
import java.util.Optional;
import java.util.stream.Stream;
import org.jboss.msc.service.Service;
import org.jboss.msc.service.ServiceBuilder;
import org.jboss.msc.service.ServiceName;
import org.jboss.msc.service.ServiceTarget;
import org.jboss.msc.value.Value;
import org.wildfly.clustering.dispatcher.CommandDispatcherFactory;
import org.wildfly.clustering.provider.ServiceProviderRegistry;
import org.wildfly.clustering.server.logging.ClusteringServerLogger;
import org.wildfly.clustering.service.ValueDependency;
import org.wildfly.clustering.singleton.SingletonElectionPolicy;
import org.wildfly.clustering.singleton.SingletonService;
import org.wildfly.clustering.singleton.SingletonServiceBuilder;
import org.wildfly.clustering.singleton.election.SimpleSingletonElectionPolicy;
/**
* Builds an MSC service that is only started on one node in the cluster at any given time.
* @author Paul Ferraro
*/
public class DistributedSingletonServiceBuilder<T> implements SingletonServiceBuilder<T>, DistributedSingletonServiceContext<T> {
@SuppressWarnings("rawtypes")
private final ValueDependency<ServiceProviderRegistry> registry;
private final ValueDependency<CommandDispatcherFactory> dispatcherFactory;
private final ServiceName serviceName;
private final Service<T> primaryService;
private final Optional<Service<T>> backupService;
private volatile SingletonElectionPolicy electionPolicy = new SimpleSingletonElectionPolicy();
private volatile int quorum = 1;
public DistributedSingletonServiceBuilder(DistributedSingletonServiceBuilderContext context, ServiceName serviceName, Service<T> primaryService, Service<T> backupService) {
this.registry = context.getServiceProviderRegistryDependency();
this.dispatcherFactory = context.getCommandDispatcherFactoryDependency();
this.serviceName = serviceName;
this.primaryService = primaryService;
this.backupService = Optional.ofNullable(backupService);
}
@Override
public ServiceName getServiceName() {
return this.serviceName;
}
@Override
public ServiceBuilder<T> build(ServiceTarget target) {
SingletonService<T> service = new DistributedSingletonService<>(this);
ServiceBuilder<T> installer = target.addService(this.serviceName, service);
Stream.of(this.registry, this.dispatcherFactory).forEach(dependency -> dependency.register(installer));
return installer;
}
@Override
public SingletonServiceBuilder<T> requireQuorum(int quorum) {
if (quorum < 1) {
throw ClusteringServerLogger.ROOT_LOGGER.invalidQuorum(quorum);
}
this.quorum = quorum;
return this;
}
@Override
public SingletonServiceBuilder<T> electionPolicy(SingletonElectionPolicy electionPolicy) {
this.electionPolicy = electionPolicy;
return this;
}
@SuppressWarnings("rawtypes")
@Override
public Value<ServiceProviderRegistry> getServiceProviderRegistry() {
return this.registry;
}
@Override
public Value<CommandDispatcherFactory> getCommandDispatcherFactory() {
return this.dispatcherFactory;
}
@Override
public Service<T> getPrimaryService() {
return this.primaryService;
}
@Override
public Optional<Service<T>> getBackupService() {
return this.backupService;
}
@Override
public SingletonElectionPolicy getElectionPolicy() {
return this.electionPolicy;
}
@Override
public int getQuorum() {
return this.quorum;
}
}