/*
 * Copyright (c) "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 <http://www.gnu.org/licenses/>.
 */
package org.neo4j.io.pagecache.impl.muninn;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * A free page in the MuninnPageCache.freelist.
 *
 * The next pointers are always other FreePage instances.
 */
final class FreePage {
    final long pageRef;
    int count;
    Object next;

    FreePage(long pageRef) {
        this.pageRef = pageRef;
    }

    void setNext(int pageCount, Object next) {
        this.next = next;
        if (next == null) {
            count = 1;
        } else if (next.getClass() == AtomicInteger.class) {
            count = 1 + pageCount - ((AtomicInteger) next).get();
        } else {
            this.count = 1 + ((FreePage) next).count;
        }
    }
}
