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This component provides the means to set up a cluster of Neo4j instances that act together as a cluster, providing Master-Slave replication and other features.

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/*
 * Copyright (c) 2002-2016 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the 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.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see .
 */
package org.neo4j.kernel.ha;

import java.io.File;
import java.util.Map;

import org.neo4j.kernel.ha.cluster.HighAvailabilityMemberState;
import org.neo4j.kernel.ha.cluster.HighAvailabilityMemberStateMachine;
import org.neo4j.kernel.ha.cluster.member.ClusterMembers;
import org.neo4j.kernel.ha.cluster.modeswitch.HighAvailabilityModeSwitcher;
import org.neo4j.kernel.ha.factory.HighlyAvailableEditionModule;
import org.neo4j.kernel.impl.factory.DatabaseInfo;
import org.neo4j.kernel.impl.factory.GraphDatabaseFacade;
import org.neo4j.kernel.impl.factory.GraphDatabaseFacadeFactory;

/**
 * This has all the functionality of an embedded database, with the addition of services
 * for handling clustering.
 */
public class HighlyAvailableGraphDatabase extends GraphDatabaseFacade
{
    public HighlyAvailableGraphDatabase( File storeDir, Map params,
            GraphDatabaseFacadeFactory.Dependencies dependencies )
    {
        newHighlyAvailableFacadeFactory().initFacade( storeDir, params, dependencies, this );
    }

    // used for testing in a different project, please do not remove
    protected GraphDatabaseFacadeFactory newHighlyAvailableFacadeFactory()
    {
        return new GraphDatabaseFacadeFactory( DatabaseInfo.HA, HighlyAvailableEditionModule::new );
    }

    public HighAvailabilityMemberState getInstanceState()
    {
        return getDependencyResolver().resolveDependency( HighAvailabilityMemberStateMachine.class ).getCurrentState();
    }

    public String role()
    {
        return getDependencyResolver().resolveDependency( ClusterMembers.class ).getCurrentMemberRole();
    }

    public boolean isMaster()
    {
        return HighAvailabilityModeSwitcher.MASTER.equals( role() );
    }

    public File getStoreDirectory()
    {
        return new File( getStoreDir() );
    }
}