/*
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* ProGuard -- shrinking, optimization, obfuscation, and preverification
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* of Java bytecode.
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*
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* Copyright (c) 2002-2014 Eric Lafortune (eric@graphics.cornell.edu)
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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package proguard.obfuscate;
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import java.util.*;
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/**
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* This <code>NameFactory</code> generates unique short names, using mixed-case
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* characters or lower-case characters only.
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*
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* @author Eric Lafortune
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*/
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public class SimpleNameFactory implements NameFactory
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{
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private static final int CHARACTER_COUNT = 26;
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private static final List cachedMixedCaseNames = new ArrayList();
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private static final List cachedLowerCaseNames = new ArrayList();
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private final boolean generateMixedCaseNames;
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private int index = 0;
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/**
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* Creates a new <code>SimpleNameFactory</code> that generates mixed-case names.
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*/
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public SimpleNameFactory()
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{
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this(true);
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}
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/**
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* Creates a new <code>SimpleNameFactory</code>.
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* @param generateMixedCaseNames a flag to indicate whether the generated
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* names will be mixed-case, or lower-case only.
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*/
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public SimpleNameFactory(boolean generateMixedCaseNames)
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{
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this.generateMixedCaseNames = generateMixedCaseNames;
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}
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// Implementations for NameFactory.
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public void reset()
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{
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index = 0;
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}
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public String nextName()
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{
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return name(index++);
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}
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/**
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* Returns the name at the given index.
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*/
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private String name(int index)
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{
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// Which cache do we need?
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List cachedNames = generateMixedCaseNames ?
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cachedMixedCaseNames :
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cachedLowerCaseNames;
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// Do we have the name in the cache?
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if (index < cachedNames.size())
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{
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return (String)cachedNames.get(index);
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}
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// Create a new name and cache it.
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String name = newName(index);
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cachedNames.add(index, name);
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return name;
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}
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/**
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* Creates and returns the name at the given index.
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*/
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private String newName(int index)
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{
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// If we're allowed to generate mixed-case names, we can use twice as
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// many characters.
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int totalCharacterCount = generateMixedCaseNames ?
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2 * CHARACTER_COUNT :
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CHARACTER_COUNT;
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int baseIndex = index / totalCharacterCount;
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int offset = index % totalCharacterCount;
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char newChar = charAt(offset);
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String newName = baseIndex == 0 ?
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new String(new char[] { newChar }) :
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(name(baseIndex-1) + newChar);
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return newName;
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}
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/**
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* Returns the character with the given index, between 0 and the number of
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* acceptable characters.
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*/
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private char charAt(int index)
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{
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return (char)((index < CHARACTER_COUNT ? 'a' - 0 :
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'A' - CHARACTER_COUNT) + index);
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}
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public static void main(String[] args)
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{
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System.out.println("Some mixed-case names:");
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printNameSamples(new SimpleNameFactory(true), 60);
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System.out.println("Some lower-case names:");
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printNameSamples(new SimpleNameFactory(false), 60);
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System.out.println("Some more mixed-case names:");
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printNameSamples(new SimpleNameFactory(true), 80);
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System.out.println("Some more lower-case names:");
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printNameSamples(new SimpleNameFactory(false), 80);
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}
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private static void printNameSamples(SimpleNameFactory factory, int count)
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{
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for (int counter = 0; counter < count; counter++)
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{
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System.out.println(" ["+factory.nextName()+"]");
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}
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}
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}
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