/* $Id: SimpleNameFactory.java,v 1.2 2004/11/20 15:41:24 eric Exp $ * * ProGuard -- shrinking, optimization, and obfuscation of Java class files. * * Copyright (c) 2002-2004 Eric Lafortune (eric@graphics.cornell.edu) * * 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 proguard.obfuscate;import java.util.*;/** * This <code>NameFactory</code> generates unique short names, using mixed-case * characters or lower-case characters only. * * @author Eric Lafortune */public class SimpleNameFactory implements NameFactory{    private static final int CHARACTER_COUNT = 26;    private static final List cachedMixedCaseNames = new ArrayList();    private static final List cachedLowerCaseNames = new ArrayList();    private boolean generateMixedCaseNames;    private int     index = 0;    /**     * Creates a new <code>SimpleNameFactory</code> that generates mixed-case names.     */    public SimpleNameFactory()    {        this(true);    }    /**     * Creates a new <code>SimpleNameFactory</code>.     * @param generateMixedCaseNames a flag to indicate whether the generated     *                               names will be mixed-case, or lower-case only.     */    public SimpleNameFactory(boolean generateMixedCaseNames)    {        this.generateMixedCaseNames = generateMixedCaseNames;    }    // Implementations for NameFactory.    public void reset()    {        index = 0;    }    public String nextName()    {        return name(index++);    }    /**     * Returns the name at the given index.     */    private String name(int index)    {        // Which cache do we need?        List cachedNames = generateMixedCaseNames ?            cachedMixedCaseNames :            cachedLowerCaseNames;        // Do we have the name in the cache?        if (index < cachedNames.size())        {            return (String)cachedNames.get(index);        }        // Create a new name and cache it.        String name = newName(index);        cachedNames.add(index, name);        return name;    }    /**     * Creates and returns the name at the given index.     */    private String newName(int index)    {        // If we're allowed to generate mixed-case names, we can use twice as        // many characters.        int totalCharacterCount = generateMixedCaseNames ?            2 * CHARACTER_COUNT :            CHARACTER_COUNT;        int baseIndex = index / totalCharacterCount;        int offset    = index % totalCharacterCount;        char newChar = charAt(offset);        String newName = baseIndex == 0 ?            new String(new char[] { newChar }) :            (name(baseIndex-1) + newChar);        return newName;    }    /**     * Returns the character with the given index, between 0 and the number of     * acceptable characters.     */    private char charAt(int index)    {        return (char)((index < CHARACTER_COUNT ? 'a' - 0               :                                                 'A' - CHARACTER_COUNT) + index);    }    public static void main(String[] args)    {        System.out.println("Some mixed-case names:");        printNameSamples(new SimpleNameFactory(true), 60);        System.out.println("Some lower-case names:");        printNameSamples(new SimpleNameFactory(false), 60);        System.out.println("Some more mixed-case names:");        printNameSamples(new SimpleNameFactory(true), 80);        System.out.println("Some more lower-case names:");        printNameSamples(new SimpleNameFactory(false), 80);    }    private static void printNameSamples(SimpleNameFactory factory, int count)    {        for (int counter = 0; counter < count; counter++)        {            System.out.println("  ["+factory.nextName()+"]");        }    }}