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Input/output abstraction layer for Neo4j.

There is a newer version: 5.26.1

/*
 * 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 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.io.pagecache.tracing;

import org.neo4j.io.pagecache.PageSwapper;

/**
 * Represents the opportunity to flush a page.
 *
 * The flushing might not happen, though, because only dirty pages are flushed.
 */
public interface FlushEventOpportunity
{
    /**
     * A FlushEventOpportunity that only returns the FlushEvent.NULL.
     */
    FlushEventOpportunity NULL = new FlushEventOpportunity()
    {
        @Override
        public FlushEvent beginFlush( long filePageId, int cachePageId, PageSwapper swapper )
        {
            return FlushEvent.NULL;
        }
    };

    /**
     * Begin flushing the given page.
     */
    public FlushEvent beginFlush( long filePageId, int cachePageId, PageSwapper swapper );
}