| /******************************************************************************* |
| * Copyright (c) 2000, 2016 IBM Corporation and others. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0. |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| *******************************************************************************/ |
| package org.eclipse.dltk.compiler.util; |
| |
| /** |
| * Hashtable for non-zero long keys. |
| */ |
| |
| public final class HashtableOfLong { |
| // to avoid using Enumerations, walk the individual tables skipping nulls |
| public long[] keyTable; |
| public Object[] valueTable; |
| |
| public int elementSize; // number of elements in the table |
| 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; |
| } |
| public Object get(long key) { |
| int length = keyTable.length, |
| index = ((int)(key >>> 32)) % length; |
| long currentKey; |
| while ((currentKey = keyTable[index]) != 0) { |
| if (currentKey == key) return valueTable[index]; |
| if (++index == length) { |
| index = 0; |
| } |
| } |
| return null; |
| } |
| public Object put(long key, Object value) { |
| int length = keyTable.length, |
| index = ((int)(key >>> 32)) % length; |
| long currentKey; |
| while ((currentKey = keyTable[index]) != 0) { |
| if (currentKey == key) return 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; |
| } |
| private void rehash() { |
| HashtableOfLong 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, 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; |
| } |
| } |