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ONgDB kernel is a lightweight, embedded Java database designed to store data structured as graphs rather than tables. For more information, see https://graphfoundation.org.

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/*
 * Copyright (c) 2018-2020 "Graph Foundation,"
 * Graph Foundation, Inc. [https://graphfoundation.org]
 *
 * This file is part of ONgDB.
 *
 * ONgDB 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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
/*
 * Copyright (c) 2002-2020 "Neo4j,"
 * Neo4j Sweden AB [http://neo4j.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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.kernel.impl.locking.community;

import org.neo4j.helpers.MathUtil;
import org.neo4j.storageengine.api.lock.ResourceType;

public class LockResource
{
    private final ResourceType resourceType;
    private final long resourceId;

    /** Local reference count, used for each client to count references to a lock. */
    private int refCount = 1;

    public LockResource( ResourceType resourceType, long resourceId )
    {
        this.resourceType = resourceType;
        this.resourceId = resourceId;
    }

    @Override
    public boolean equals( Object o )
    {
        if ( this == o )
        {
            return true;
        }
        if ( o == null || getClass() != o.getClass() )
        {
            return false;
        }

        LockResource that = (LockResource) o;
        return resourceId == that.resourceId && resourceType.equals( that.resourceType );

    }

    @Override
    public int hashCode()
    {
        int result = resourceType.hashCode();
        result = 31 * result + (int) (resourceId ^ (resourceId >>> 32));
        return result;
    }

    @Override
    public String toString()
    {
        return String.format( "%s(%d)", resourceType, resourceId );
    }

    public void acquireReference()
    {
        refCount = Math.incrementExact( refCount );
    }

    public int releaseReference()
    {
        return refCount = MathUtil.decrementExactNotPastZero( refCount );
    }

    public long resourceId()
    {
        return resourceId;
    }

    public ResourceType type()
    {
        return resourceType;
    }
}