org.neo4j.kernel.database.LogEntryWriterFactory Maven / Gradle / Ivy

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/*
 * 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 .
 */
package org.neo4j.kernel.database;

import javax.annotation.Nullable;

import org.neo4j.io.fs.WritableChecksumChannel;
import org.neo4j.kernel.KernelVersion;
import org.neo4j.kernel.impl.transaction.log.entry.LogEntryWriter;

/**
 * The LogEntryWriterFactory is responsible for picking the transaction log format version to use for LogEntryWriters. The version should be the same in one
 * complete transaction in the log but should be able to be upgraded without a restart. Therefore createEntryWriter should be used to get a new LogEntryWriter
 * for each transaction.
 */
@FunctionalInterface
public interface LogEntryWriterFactory
{
     LogEntryWriter createEntryWriter( T channel );

    default  LogEntryWriter createEntryWriter( T channel, @Nullable KernelVersion version )
    {
        return version == null ? createEntryWriter( channel ) : new LogEntryWriter<>( channel, version );
    }
}