forkmessagewriter.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-@year@ by SMB GmbH. All rights reserved.
//
// $Id: ForkMessageWriter.java,v 1.2 2003/11/07 21:34:22 per_nyfelt Exp $
package org.ozoneDB.tools.OPP.message;

import org.ozoneDB.tools.OPP.message.command.*;

import java.util.LinkedList;

/**
 *
 * @author Joakim Ohlrogge
 */
public class ForkMessageWriter implements MessageWriter {
    private int level = 0;
    private MessageWriter rootWriter;
    private LinkedList queue = new LinkedList();

    private void enque(MessageCommand command) {
        if (level == 0)
            command.execute();
        else
            queue.addLast(command);
    }

    private void dumpQueue() {
        while (!queue.isEmpty()) {
            MessageCommand command = (MessageCommand) queue.removeFirst();
            command.execute();
        }

    }

    public ForkMessageWriter(MessageWriter rootWriter) {
        this.rootWriter = rootWriter;
    }

    public void startGeneration(String object) {
        ++level;
        enque(new BeginCommand(rootWriter, object));
    }

    public void error(String message) {
        enque(new ErrorCommand(rootWriter, message));
    }

    public void warning(String message) {
        enque(new WarningCommand(rootWriter, message));
    }

    public void warning(String filename, int row, String message) {
        enque(new LocationWarningCommand(rootWriter, message, filename, row));
    }

    public void info(String message) {
        enque(new InfoCommand(rootWriter, message));
    }

    public void debug(String message) {
        enque(new DebugCommand(rootWriter, message));
    }

    public void endGeneration() {
        enque(new EndCommand(rootWriter));
        --level;
        if (level == 0)
            dumpQueue();
    }
}