Subversion Repositories mkgmap

/*
 * Copyright (C) 2011.
 *
 * 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.app.mdr;

import java.util.List;

import uk.me.parabola.imgfmt.app.ImgFileWriter;

/**
 * Name indexes consisting of a prefix of the string and the record
 * number at which that prefix first occurs. So it is like 8 and 12
 * except that they are all combined together in this one section.
 *
 * @author Steve Ratcliffe
 */
public class Mdr17 extends MdrSection {
        private PrefixIndex streets;
        private PrefixIndex streetsByCountry;
        private PrefixIndex cities;
        private PrefixIndex pois;

        public Mdr17(MdrConfig config) {
                setConfig(config);
                streets = new PrefixIndex(getConfig(), 4);             
                streetsByCountry = new PrefixIndex(getConfig(), 4);
                cities = new PrefixIndex(getConfig(), 2);
                pois = new PrefixIndex(getConfig(), 4);
        }

        public void writeSectData(ImgFileWriter writer) {
                writeSubSect(writer, streets);
                writeSubSect(writer, cities);
                writeSubSect(writer, streetsByCountry);
                writeSubSect(writer, pois);
        }

        /**
         * Write one of the subsections that makes up the section. They are all similar and
         * have a header with the length and the record size and prefix length of the
         * records in the subsection.
         */
        private void writeSubSect(ImgFileWriter writer, PrefixIndex index) {
                index.preWrite();
                int len = index.getItemSize() * index.getNumberOfItems() + 2;
                if (len == 2)
                        return; // nothing to do

                // The length is a variable length integer with the length indicated by a suffix.
                len = (len << 1) + 1;
                int mask = ~0xff;
                int count = 1;
                while ((len & mask) != 0) {
                        mask <<= 8;
                        len <<= 1;
                        count++;
                }
                writer.putN(count, len);

                // Calculate the header. This code is unlikely to survive the finding of another example!
                // Have no idea what the real thinking behind this is.
                int prefixLength = index.getPrefixLength();
                int header = (prefixLength - 1) << 8;
                header += (prefixLength + 1) * (prefixLength + 1);
                header += (index.getItemSize() - prefixLength - 1) * 0xa;

                writer.putChar((char) header);
                index.writeSectData(writer);
        }

        protected void releaseMemory() {
                streets = null;
                cities = null;
                streetsByCountry = null;
                pois = null;
        }

        public void addStreets(List<Mdr7Record> streetList) {
                streets.createFromList(streetList);
        }

        public void addCities(List<Mdr5Record> cityList) {
                cities.createFromList(cityList);
        }

        public void addStreetsByCountry(List<Mdr7Record> streets) {
                streetsByCountry.createFromList(streets, true);
        }

        public void addPois(List<Mdr11Record> poiList) {
                pois.createFromList(poiList);
        }

        public int getItemSize() {
                return 0;
        }

        protected int numberOfItems() {
                return 0;
        }
}