| /******************************************************************************* |
| * Copyright (c) 2000, 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.core.util; |
| |
| import org.eclipse.jdt.core.compiler.CharOperation; |
| |
| public final class SimpleWordSet { |
| |
| // to avoid using Enumerations, walk the individual values skipping nulls |
| public char[][] words; |
| public int elementSize; // number of elements in the table |
| public int threshold; |
| |
| public SimpleWordSet(int size) { |
| this.elementSize = 0; |
| this.threshold = size; // size represents the expected number of elements |
| int extraRoom = (int) (size * 1.5f); |
| if (this.threshold == extraRoom) |
| extraRoom++; |
| this.words = new char[extraRoom][]; |
| } |
| |
| public char[] add(char[] word) { |
| int length = this.words.length; |
| int index = CharOperation.hashCode(word) % length; |
| char[] current; |
| while ((current = words[index]) != null) { |
| if (CharOperation.equals(current, word)) return current; |
| if (++index == length) index = 0; |
| } |
| words[index] = word; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++elementSize > threshold) rehash(); |
| return word; |
| } |
| |
| public boolean includes(char[] word) { |
| int length = this.words.length; |
| int index = CharOperation.hashCode(word) % length; |
| char[] current; |
| while ((current = words[index]) != null) { |
| if (CharOperation.equals(current, word)) return true; |
| if (++index == length) index = 0; |
| } |
| return false; |
| } |
| |
| private void rehash() { |
| SimpleWordSet newSet = new SimpleWordSet(elementSize * 2); // double the number of expected elements |
| char[] current; |
| for (int i = words.length; --i >= 0;) |
| if ((current = words[i]) != null) |
| newSet.add(current); |
| |
| this.words = newSet.words; |
| this.elementSize = newSet.elementSize; |
| this.threshold = newSet.threshold; |
| } |
| } |