| /******************************************************************************* |
| * 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; |
| |
| /** |
| * Hashtable of {Object[] --> Object } |
| */ |
| public final class HashtableOfArrayToObject implements Cloneable { |
| |
| // to avoid using Enumerations, walk the individual tables skipping nulls |
| public Object[][] keyTable; |
| public Object[] valueTable; |
| |
| public int elementSize; // number of elements in the table |
| int threshold; |
| |
| public HashtableOfArrayToObject() { |
| this(13); |
| } |
| |
| public HashtableOfArrayToObject(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.keyTable = new Object[extraRoom][]; |
| this.valueTable = new Object[extraRoom]; |
| } |
| |
| public Object clone() throws CloneNotSupportedException { |
| HashtableOfArrayToObject result = (HashtableOfArrayToObject) super.clone(); |
| result.elementSize = this.elementSize; |
| result.threshold = this.threshold; |
| |
| int length = this.keyTable.length; |
| result.keyTable = new Object[length][]; |
| System.arraycopy(this.keyTable, 0, result.keyTable, 0, length); |
| |
| length = this.valueTable.length; |
| result.valueTable = new Object[length]; |
| System.arraycopy(this.valueTable, 0, result.valueTable, 0, length); |
| return result; |
| } |
| |
| public boolean containsKey(Object[] key) { |
| int length = this.keyTable.length; |
| int index = hashCode(key) % length; |
| int keyLength = key.length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) |
| return true; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return false; |
| } |
| |
| public Object get(Object[] key) { |
| int length = this.keyTable.length; |
| int index = hashCode(key) % length; |
| int keyLength = key.length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) |
| return this.valueTable[index]; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| |
| public int getIndex(Object[] key) { |
| int length = this.keyTable.length; |
| int index = hashCode(key) % length; |
| int keyLength = key.length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) |
| return index; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return -1; |
| } |
| |
| public Object[] getKey(Object[] key, int keyLength) { |
| int length = this.keyTable.length; |
| int index = hashCode(key, keyLength) % length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArrays(currentKey, key, keyLength)) |
| return currentKey; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| |
| 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 put(Object[] key, Object value) { |
| int length = this.keyTable.length; |
| int index = hashCode(key) % length; |
| int keyLength = key.length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) |
| return this.valueTable[index] = value; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| this.keyTable[index] = key; |
| this.valueTable[index] = value; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++this.elementSize > this.threshold) |
| rehash(); |
| return value; |
| } |
| |
| public Object removeKey(Object[] key) { |
| int length = this.keyTable.length; |
| int index = hashCode(key) % length; |
| int keyLength = key.length; |
| Object[] currentKey; |
| while ((currentKey = this.keyTable[index]) != null) { |
| if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) { |
| Object value = this.valueTable[index]; |
| this.elementSize--; |
| this.keyTable[index] = null; |
| this.valueTable[index] = null; |
| rehash(); |
| return value; |
| } |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| |
| private void rehash() { |
| |
| HashtableOfArrayToObject newHashtable = new HashtableOfArrayToObject(this.elementSize * 2); // double the number of expected elements |
| Object[] currentKey; |
| for (int i = this.keyTable.length; --i >= 0;) |
| if ((currentKey = this.keyTable[i]) != null) |
| newHashtable.put(currentKey, this.valueTable[i]); |
| |
| this.keyTable = newHashtable.keyTable; |
| this.valueTable = newHashtable.valueTable; |
| this.threshold = newHashtable.threshold; |
| } |
| |
| public int size() { |
| return this.elementSize; |
| } |
| |
| public String toString() { |
| StringBuffer buffer = new StringBuffer(); |
| Object[] element; |
| for (int i = 0, length = this.keyTable.length; i < length; i++) |
| if ((element = this.keyTable[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("} -> "); //$NON-NLS-1$ |
| buffer.append(this.valueTable[i]); |
| if (i != length-1) |
| buffer.append('\n'); |
| } |
| return buffer.toString(); |
| } |
| } |