/*
 * 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.kernel.impl.transaction.log;

/**
 * Mutable marker that can create immutable {@link LogPosition} objects when requested to.
 */
public class LogPositionMarker {
    private long logVersion;
    private long byteOffset;
    private boolean specified;

    public void mark(long logVersion, long byteOffset) {
        this.logVersion = logVersion;
        this.byteOffset = byteOffset;
        this.specified = true;
    }

    public void unspecified() {
        specified = false;
    }

    public LogPosition newPosition() {
        return specified ? new LogPosition(logVersion, byteOffset) : LogPosition.UNSPECIFIED;
    }

    public long getLogVersion() {
        return logVersion;
    }

    public long getByteOffset() {
        return byteOffset;
    }

    public boolean isMarkerInLog(long logVersion) {
        return specified && this.logVersion == logVersion;
    }

    @Override
    public String toString() {
        return "Mark:" + newPosition();
    }
}
