ja.lingo.engine.searchindex.NodeSerializer.java Source code

Introduction

Here is the source code for ja.lingo.engine.searchindex.NodeSerializer.java

Source

/*
 * JaLingo, http://jalingo.sourceforge.net/
 *
 * Copyright (c) 2002-2006 Oleksandr Shyshko
 *
 * This program 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package ja.lingo.engine.searchindex;

import ja.centre.util.assertions.Arguments;
import ja.centre.util.assertions.States;
import ja.centre.util.io.Files;
import ja.centre.util.measurer.TimeMeasurer;
import ja.lingo.engine.util.EngineFiles;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.BufferedOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

class NodeSerializer {
    private static final Log LOG = LogFactory.getLog(NodeSerializer.class);

    private DataOutputStream tempDos;
    private int firstLevelNodesCount;

    private String fileName;
    private TimeMeasurer timeMeasurer;
    private String tempFileName;

    public NodeSerializer(String fileName) throws IOException {
        Arguments.assertNotNull("fileName", fileName);
        this.fileName = fileName;

        tempFileName = EngineFiles.createTemp("search.index");

        tempDos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(tempFileName)));

        timeMeasurer = new TimeMeasurer(false);
    }

    public void serialize(INode node) throws IOException {
        firstLevelNodesCount++;

        serialize(node, tempDos);
    }

    public void close() throws IOException {
        tempDos.close();

        LOG.info("calculateSize(...) spent " + timeMeasurer);

        long size = Files.length(tempFileName);
        if (size > Integer.MAX_VALUE) {
            States.doThrow("File is \"" + fileName + "\"to large. Maximum allowed size is " + Integer.MAX_VALUE
                    + ". Actual size is " + size);
        }

        FileOutputStream fos = new FileOutputStream(fileName);

        DataOutputStream dos = new DataOutputStream(fos);
        serializeNodeHeader(dos, (int) size, firstLevelNodesCount, '\u0000', 0);
        dos.flush();

        EngineFiles.appendFileAndDelete(tempFileName, fos);
        fos.close();
    }

    private void serialize(INode node, DataOutputStream dos) throws IOException {
        Arguments.assertNotNull("node", node);

        int size = calculateSize(node);
        serializeNodeHeader(dos, size, node.childrenCount(), node.getKey(), node.getValue());

        for (int i = 0; i < node.childrenCount(); i++) {
            serialize(node.getChild(i), dos);
        }
    }

    private void serializeNodeHeader(DataOutputStream dos, int size, int childrenCount, char key, int value)
            throws IOException {
        dos.writeInt(size);
        dos.writeInt(childrenCount);
        dos.writeInt(key);
        dos.writeInt(value);
    }

    private static final int HEADER_SIZE = 16;
    private int size;

    private int calculateSize(INode node) {
        timeMeasurer.start();

        size = 0;
        _calculateSize(node);

        timeMeasurer.stop();

        return size;
    }

    private void _calculateSize(INode node) {
        size += HEADER_SIZE;
        for (int i = 0; i < node.childrenCount(); i++) {
            _calculateSize(node.getChild(i));
        }
    }

}