Subversion Repositories mkgmap

/*
 * Copyright (C) 2009.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 or
 * version 2 as published by the Free Software Foundation.
 *
 * 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.
 */

package uk.me.parabola.imgfmt.mdxfmt;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 * The MDX index file.  Used with the global index.  This is located
 * at the family level in the windows registry and can perhaps index
 * across different products (and maybe families), although such a thing
 * hasn't been seen.
 *
 * @author Steve Ratcliffe
 */
public class MdxFile {
        private final char familyId;
        private final char productId;
       
        private final List<MapInfo> maps = new ArrayList<MapInfo>();

        /**
         * Create with default family and product ids.
         * @param familyId The default family id that will be used if no other one
         * is supplied.
         * @param productId The default product id for the maps indexed by this
         * file.
         */
        public MdxFile(int familyId, int productId) {
                this.familyId = (char) familyId;
                this.productId = (char) productId;
        }

        /**
         * Add a map with the default family and product id's and with equal
         * name and hex name.
         * @param name The map name (from the filename of the map) as an integer.
         * @param hexname The map id that is inside the TRE header
         * @param filename The file name of the map being added. Mainly for diagnostics,
         * it is not needed for the file.
         */
        public void addMap(int name, int hexname, String filename) {
                MapInfo info = new MapInfo();
                info.setHexMapname(hexname);
                info.setMapname(name);
                info.setFamilyId(familyId);
                info.setProductId(productId);
                info.setFilename(filename);

                maps.add(info);
        }

        /**
         * Write the file out to the given filename.
         */
        public void write(String filename) throws IOException {
                FileOutputStream stream = new FileOutputStream(filename);
                FileChannel chan = stream.getChannel();
                ByteBuffer buf = ByteBuffer.allocate(1024);
                buf.order(ByteOrder.LITTLE_ENDIAN);

                try {
                        writeHeader(chan, buf);
                        writeBody(chan, buf);
                } finally {
                        chan.close();
                }
        }

        private void writeHeader(WritableByteChannel chan, ByteBuffer buf) throws IOException {
                try {
                        buf.put("Midx".getBytes("ascii"));
                } catch (UnsupportedEncodingException e) {
                        throw new IOException("Could not write header");
                }
                buf.putChar((char) 100);
                buf.putInt(12);
                buf.putInt(maps.size());

                buf.flip();
                chan.write(buf);
        }

        private void writeBody(WritableByteChannel chan, ByteBuffer buf) throws IOException {
                // Sort the maps by the hex number.
                Collections.sort(maps, new Comparator<MapInfo>() {
                        public int compare(MapInfo o1, MapInfo o2) {
                                if (o1.getHexMapname() == o2.getHexMapname())
                                        return 0;
                                else if (o1.getHexMapname() < o2.getHexMapname())
                                        return -1;
                                else
                                        return 1;
                        }
                });

                for (MapInfo info : maps) {
                        // Although its not necessarily wrong for them to be zero, it probably
                        // sign that something is wrong.
                        if (info.getHexMapname() == 0 || info.getMapname() == 0)
                                System.err.println("Invalid mapname for " + info.getFilename() + ", perhaps it is not a .img file");

                        buf.compact();
                        info.write(buf);

                        buf.flip();
                        chan.write(buf);
                }
        }
}