| /******************************************************************************* |
| * Copyright (c) 2000, 2009 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.core.util; |
| |
| /** |
| * HashSet of Object[] |
| */ |
| public final class HashSetOfArray implements Cloneable { |
| |
| // to avoid using Enumerations, walk the individual tables skipping nulls |
| public Object[][] set; |
| |
| public int elementSize; // number of elements in the table |
| int threshold; |
| |
| public HashSetOfArray() { |
| this(13); |
| } |
| |
| public HashSetOfArray(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 Object[extraRoom][]; |
| } |
| |
| public Object clone() throws CloneNotSupportedException { |
| HashSetOfArray result = (HashSetOfArray) super.clone(); |
| result.elementSize = this.elementSize; |
| result.threshold = this.threshold; |
| |
| int length = this.set.length; |
| result.set = new Object[length][]; |
| System.arraycopy(this.set, 0, result.set, 0, length); |
| |
| return result; |
| } |
| |
| public boolean contains(Object[] array) { |
| int length = this.set.length; |
| int index = hashCode(array) % length; |
| int arrayLength = array.length; |
| Object[] currentArray; |
| while ((currentArray = this.set[index]) != null) { |
| if (currentArray.length == arrayLength && Util.equalArraysOrNull(currentArray, array)) |
| return true; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return false; |
| } |
| |
| private int hashCode(Object[] element) { |
| return hashCode(element, element.length); |
| } |
| |
| private int hashCode(Object[] element, int length) { |
| int hash = 0; |
| for (int i = length-1; i >= 0; i--) |
| hash = Util.combineHashCodes(hash, element[i].hashCode()); |
| return hash & 0x7FFFFFFF; |
| } |
| |
| public Object add(Object[] array) { |
| int length = this.set.length; |
| int index = hashCode(array) % length; |
| int arrayLength = array.length; |
| Object[] currentArray; |
| while ((currentArray = this.set[index]) != null) { |
| if (currentArray.length == arrayLength && Util.equalArraysOrNull(currentArray, array)) |
| return this.set[index] = array; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| this.set[index] = array; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++this.elementSize > this.threshold) |
| rehash(); |
| return array; |
| } |
| |
| public Object remove(Object[] array) { |
| int length = this.set.length; |
| int index = hashCode(array) % length; |
| int arrayLength = array.length; |
| Object[] currentArray; |
| while ((currentArray = this.set[index]) != null) { |
| if (currentArray.length == arrayLength && Util.equalArraysOrNull(currentArray, array)) { |
| Object existing = this.set[index]; |
| this.elementSize--; |
| this.set[index] = null; |
| rehash(); |
| return existing; |
| } |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| |
| private void rehash() { |
| |
| HashSetOfArray newHashSet = new HashSetOfArray(this.elementSize * 2); // double the number of expected elements |
| Object[] currentArray; |
| for (int i = this.set.length; --i >= 0;) |
| if ((currentArray = this.set[i]) != null) |
| newHashSet.add(currentArray); |
| |
| this.set = newHashSet.set; |
| this.threshold = newHashSet.threshold; |
| } |
| |
| public int size() { |
| return this.elementSize; |
| } |
| |
| public String toString() { |
| StringBuffer buffer = new StringBuffer(); |
| Object[] element; |
| for (int i = 0, length = this.set.length; i < length; i++) |
| if ((element = this.set[i]) != null) { |
| buffer.append('{'); |
| for (int j = 0, length2 = element.length; j < length2; j++) { |
| buffer.append(element[j]); |
| if (j != length2-1) |
| buffer.append(", "); //$NON-NLS-1$ |
| } |
| buffer.append("}"); //$NON-NLS-1$ |
| if (i != length-1) |
| buffer.append('\n'); |
| } |
| return buffer.toString(); |
| } |
| } |