org.eclipse.jdt.internal.compiler.util.HashtableOfLong Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of ecj Show documentation
This is Eclipse JDT Core Batch Compiler used by Scout SDK
The newest version!
/*******************************************************************************
 * 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.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 = this.keyTable.length,
		index = ((int)(key >>> 32)) % length;
	long currentKey;
	while ((currentKey = this.keyTable[index]) != 0) {
		if (currentKey == key)
			return true;
		if (++index == length) {
			index = 0;
		}
	}
	return false;
}
public Object get(long key) {
	int length = this.keyTable.length,
		index = ((int)(key >>> 32)) % length;
	long currentKey;
	while ((currentKey = this.keyTable[index]) != 0) {
		if (currentKey == key)  return this.valueTable[index];
		if (++index == length) {
			index = 0;
		}
	}
	return null;
}
public Object put(long key, Object value) {
	int length = this.keyTable.length,
		index = ((int)(key >>> 32)) % length;
	long currentKey;
	while ((currentKey = this.keyTable[index]) != 0) {
		if (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;
}
private void rehash() {
	HashtableOfLong newHashtable = new HashtableOfLong(this.elementSize * 2); // double the number of expected elements
	long currentKey;
	for (int i = this.keyTable.length; --i >= 0;)
		if ((currentKey = this.keyTable[i]) != 0)
			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() {
	String s = ""; //$NON-NLS-1$
	Object object;
	for (int i = 0, length = this.valueTable.length; i < length; i++)
		if ((object = this.valueTable[i]) != null)
			s += this.keyTable[i] + " -> " + object.toString() + "\n"; //$NON-NLS-2$ //$NON-NLS-1$
	return s;
}
}