| /******************************************************************************* |
| * Copyright (c) 2000, 2017 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 |
| * |
| *******************************************************************************/ |
| package org.eclipse.dltk.core.search.matching2; |
| |
| import java.util.Arrays; |
| |
| /** |
| * Hashtable for non-zero long keys. |
| */ |
| final class HashtableOfLong<E> { |
| // to avoid using Enumerations, walk the individual tables skipping nulls |
| private long[] keyTable; |
| private Object[] valueTable; |
| |
| private int elementSize; // number of elements in the table |
| private int threshold; |
| |
| public HashtableOfLong() { |
| this(13); |
| } |
| |
| public HashtableOfLong(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 long[extraRoom]; |
| this.valueTable = new Object[extraRoom]; |
| } |
| |
| public boolean containsKey(long key) { |
| int length = keyTable.length, index = ((int) (key >>> 32)) % length; |
| long currentKey; |
| while ((currentKey = keyTable[index]) != 0) { |
| if (currentKey == key) |
| return true; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return false; |
| } |
| |
| @SuppressWarnings("unchecked") |
| public E get(long key) { |
| int length = keyTable.length, index = ((int) (key >>> 32)) % length; |
| long currentKey; |
| while ((currentKey = keyTable[index]) != 0) { |
| if (currentKey == key) |
| return (E) valueTable[index]; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| |
| @SuppressWarnings("unchecked") |
| public E put(long key, E value) { |
| int length = keyTable.length, index = ((int) (key >>> 32)) % length; |
| long currentKey; |
| while ((currentKey = keyTable[index]) != 0) { |
| if (currentKey == key) |
| return (E) (valueTable[index] = value); |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| keyTable[index] = key; |
| valueTable[index] = value; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++elementSize > threshold) |
| rehash(); |
| return value; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private void rehash() { |
| HashtableOfLong<E> newHashtable = new HashtableOfLong<>( |
| elementSize * 2); |
| // double the number of expected elements |
| long currentKey; |
| for (int i = keyTable.length; --i >= 0;) |
| if ((currentKey = keyTable[i]) != 0) |
| newHashtable.put(currentKey, (E) valueTable[i]); |
| |
| this.keyTable = newHashtable.keyTable; |
| this.valueTable = newHashtable.valueTable; |
| this.threshold = newHashtable.threshold; |
| } |
| |
| public int size() { |
| return elementSize; |
| } |
| |
| @Override |
| public String toString() { |
| String s = ""; //$NON-NLS-1$ |
| Object object; |
| for (int i = 0, length = valueTable.length; i < length; i++) |
| if ((object = valueTable[i]) != null) |
| s += keyTable[i] + " -> " + object.toString() + "\n"; //$NON-NLS-2$ //$NON-NLS-1$ |
| return s; |
| } |
| |
| public void clear() { |
| if (elementSize > 0) { |
| Arrays.fill(valueTable, null); |
| Arrays.fill(keyTable, 0); |
| elementSize = 0; |
| } |
| } |
| } |