Subversion Repositories display

/*
 * 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 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 test.display.check;

import test.display.Section;
import uk.me.parabola.imgfmt.app.ImgFileReader;

import java.nio.charset.Charset;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Read and cache all the strings in the mdr15 section.
 *
 * Has to be read with regard to the code page that the file is written in.
 */
public class MdrStrings {
        private final ImgFileReader reader;
        private final Section mdr15;
        private final Charset charset;
        private boolean compressedStrings;
        private Map<Integer, String> stringTable;

        public MdrStrings(ImgFileReader reader, Section mdr15, Charset charset) {
                this.reader = reader;
                this.mdr15 = mdr15;
                this.charset = charset;
        }

        /**
         * Get a string from the string section.
         *
         * @param off The offset in the text section.
         * @return The resultant string.
         */
        public String getTextString(int off) {
                if (compressedStrings)
                        return "";

                if (stringTable == null)
                        readAllStrings();

                return stringTable.get(off);
        }

        public void readAllStrings() {
                if (compressedStrings)
                        return;  // we don't know how to do this yet.

                stringTable = new LinkedHashMap<Integer, String>();

                // Remember where we are
                long rem = reader.position();

                long start = mdr15.getStart();
                long end = mdr15.getEnd();
                int magic = mdr15.getMagic();
                if ((magic & 0x1) != 0) {
                        // We can't read these, so remember the fact and return
                        compressedStrings = true;
                        return;
                }

                reader.position(start);

                byte[] buffer = new byte[1024];
                int len = 0;
                int offset = 0;
                while (reader.position() < end) {
                        byte b = reader.get();
                        if (b == 0) {
                                String str = new String(buffer, 0, len, charset);
                                stringTable.put(offset, str);
                                offset = (int) (reader.position() - start);
                                len = 0;
                        } else {
                                buffer[len++] = b;
                        }
                }

                // Return to our callers position
                reader.position(rem);
        }
}