/*
* Copyright (C) 2012.
*
* 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.mkgmap.main;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import uk.me.parabola.imgfmt.ExitException;
import uk.me.parabola.imgfmt.Utils;
import uk.me.parabola.mkgmap.CommandArgs;
/**
* Ensure that the TYP file has the correct family and product id's as given by the
* command line arguments.
*
* If they are correct, then returns the original name and nothing else is done.
*
* If they are not correct, then a new file is created which patches the id's
* and its name is returned.
*/
class TypSaver implements MapProcessor {
public String makeMap(CommandArgs args, String filename) {
String outfilename = filename;
// These are the family and product id's that are wanted.
int familyId = args.get("family-id", CommandArgs.DEFAULT_FAMILYID);
int productId = args.get("product-id", CommandArgs.DEFAULT_PRODUCTID);
FileInputStream in = null;
try {
in = new FileInputStream(filename);
byte[] buf = new byte[256];
int n = in.read(buf);
ByteBuffer buffer = ByteBuffer.wrap(buf);
buffer.order(ByteOrder.LITTLE_ENDIAN);
// Get the product and family id's that are actually in the supplied TYP file.
int foundFamily = buffer.getChar(0x2f);
int foundProduct = buffer.getChar(0x31);
if (familyId != foundFamily || productId != foundProduct) {
buffer.putChar(0x2f, (char) familyId);
buffer.putChar(0x31, (char) productId);
outfilename = makeOutName(filename);
writeAlteredTyp(outfilename, in, buf, n);
}
} catch (IOException e) {
throw new ExitException("TYP file cannot be opened or read: " + filename);
} finally {
Utils.closeFile(in);
}
return outfilename;
}
/**
* Write out the altered TYP file.
*
* @param outFilename The name to write to.
* @param in The input file. This has already had the first block read from it.
* @param buf The buffer holding the first block of the file. It is already modified, so just needs
* to be written out.
* @param n The number of characters in the first block. The minimum size of the TYP file is
* less than the buffer size.
*/
private void writeAlteredTyp(String outFilename, FileInputStream in, byte[] buf, int n) {
FileOutputStream out = null;
try {
out = new FileOutputStream(outFilename);
do {
out.write(buf, 0, n);
} while ((n = in.read(buf)) > 0);
} catch (IOException e) {
throw new ExitException("Could not write temporary TYP file: " + outFilename);
} finally {
Utils.closeFile(out);
}
}
/**
* Create a name for the patched file.
*
* We pre-pend a 'x' to the name part of the path.
*
* If the name is already 8+3 characters, then the name that appears inside the gmapsupp, will
* not have the added character and so it is possible to have internal files with the same name.
* I don't think this matters, since I don't think that the name is important, but I could be wrong.
*
* @param path The original name
* @return The modified name.
*/
private String makeOutName(String path) {
File f = new File(path);
File dir = f.getParentFile();
String name = f.getName();
File out = new File(dir, "x" + name);
return out.getPath();
}
}