Copyright (c) 2000, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.util;

 
Hashtable for non-zero int keys.
/**
  *	Hashtable for non-zero int keys.
  */

public final class HashtableOfInt {
	// to avoid using Enumerations, walk the individual tables skipping nulls
	public int[] keyTable;
	public Object[] valueTable;

	public int elementSize; // number of elements in the table
	int threshold;
public HashtableOfInt() {
	this(13);
}
public HashtableOfInt(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 int[extraRoom];
	this.valueTable = new Object[extraRoom];
}
public boolean containsKey(int key) {
	int length = this.keyTable.length, index = key % length;
	int currentKey;
	while ((currentKey = this.keyTable[index]) != 0) {
		if (currentKey == key)
			return true;
		if (++index == length) {
			index = 0;
		}
	}
	return false;
}
public Object get(int key) {
	int length = this.keyTable.length, index = key % length;
	int currentKey;
	while ((currentKey = this.keyTable[index]) != 0) {
		if (currentKey == key)  return this.valueTable[index];
		if (++index == length) {
			index = 0;
		}
	}
	return null;
}
public Object put(int key, Object value) {
	int length = this.keyTable.length, index = key % length;
	int 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() {
	HashtableOfInt newHashtable = new HashtableOfInt(this.elementSize * 2); // double the number of expected elements
	int 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;
}
@Override
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;
}
}