| /******************************************************************************* |
| * Copyright (c) 2000, 2008 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.util; |
| |
| /** |
| * HashSet of Object[] |
| */ |
| public final class HashSetOfInt implements Cloneable { |
| |
| // to avoid using Enumerations, walk the individual tables skipping nulls |
| public int[] set; |
| |
| public int elementSize; // number of elements in the table |
| int threshold; |
| |
| public HashSetOfInt() { |
| this(13); |
| } |
| |
| public HashSetOfInt(int size) { |
| |
| this.elementSize = 0; |
| this.threshold = size; // size represents the expected number of elements |
| int extraRoom = (int) (size * 1.75f); |
| if (this.threshold == extraRoom) |
| extraRoom++; |
| this.set = new int[extraRoom]; |
| } |
| |
| public Object clone() throws CloneNotSupportedException { |
| HashSetOfInt result = (HashSetOfInt) super.clone(); |
| result.elementSize = this.elementSize; |
| result.threshold = this.threshold; |
| |
| int length = this.set.length; |
| result.set = new int[length]; |
| System.arraycopy(this.set, 0, result.set, 0, length); |
| |
| return result; |
| } |
| |
| public boolean contains(int element) { |
| int length = this.set.length; |
| int index = element % length; |
| int currentElement; |
| while ((currentElement = this.set[index]) != 0) { |
| if (currentElement == element) |
| return true; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return false; |
| } |
| |
| public int add(int element) { |
| int length = this.set.length; |
| int index = element % length; |
| int currentElement; |
| while ((currentElement = this.set[index]) != 0) { |
| if (currentElement == element) |
| return this.set[index] = element; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| this.set[index] = element; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++this.elementSize > this.threshold) |
| rehash(); |
| return element; |
| } |
| |
| public int remove(int element) { |
| int length = this.set.length; |
| int index = element % length; |
| int currentElement; |
| while ((currentElement = this.set[index]) != 0) { |
| if (currentElement == element) { |
| int existing = this.set[index]; |
| this.elementSize--; |
| this.set[index] = 0; |
| rehash(); |
| return existing; |
| } |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return 0; |
| } |
| |
| private void rehash() { |
| |
| HashSetOfInt newHashSet = new HashSetOfInt(this.elementSize * 2); // double the number of expected elements |
| int currentElement; |
| for (int i = this.set.length; --i >= 0;) |
| if ((currentElement = this.set[i]) != 0) |
| newHashSet.add(currentElement); |
| |
| this.set = newHashSet.set; |
| this.threshold = newHashSet.threshold; |
| } |
| |
| public int size() { |
| return this.elementSize; |
| } |
| |
| public String toString() { |
| StringBuffer buffer = new StringBuffer(); |
| int element; |
| for (int i = 0, length = this.set.length; i < length; i++) |
| if ((element = this.set[i]) != 0) { |
| buffer.append(element); |
| if (i != length-1) |
| buffer.append('\n'); |
| } |
| return buffer.toString(); |
| } |
| } |