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 of {Object --> int[] }
/**
 * Hashtable of {Object --> int[] }
 */
public final class HashtableOfObjectToIntArray implements Cloneable {

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

	public int elementSize; // number of elements in the table
	int threshold;

	public HashtableOfObjectToIntArray() {
		this(13);
	}

	public HashtableOfObjectToIntArray(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 int[extraRoom][];
	}

	@Override
	public Object clone() throws CloneNotSupportedException {
		HashtableOfObjectToIntArray result = (HashtableOfObjectToIntArray) 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 int[length][];
		System.arraycopy(this.valueTable, 0, result.valueTable, 0, length);
		return result;
	}

	public boolean containsKey(Object key) {
		int length = this.keyTable.length,
			index = (key.hashCode()& 0x7FFFFFFF) % length;
		Object currentKey;
		while ((currentKey = this.keyTable[index]) != null) {
			if (currentKey.equals(key))
				return true;
			if (++index == length) {
				index = 0;
			}
		}
		return false;
	}

	public int[] get(Object key) {
		int length = this.keyTable.length,
			index = (key.hashCode()& 0x7FFFFFFF) % length;
		Object currentKey;
		while ((currentKey = this.keyTable[index]) != null) {
			if (currentKey.equals(key))
				return this.valueTable[index];
			if (++index == length) {
				index = 0;
			}
		}
		return null;
	}

	public void keysToArray(Object[] array) {
		int index = 0;
		for (int i=0, length=this.keyTable.length; i<length; i++) {
			if (this.keyTable[i] != null)
				array[index++] = this.keyTable[i];
		}
	}

	public int[] put(Object key, int[] value) {
		int length = this.keyTable.length,
			index = (key.hashCode()& 0x7FFFFFFF) % length;
		Object currentKey;
		while ((currentKey = this.keyTable[index]) != null) {
			if (currentKey.equals(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 int[] removeKey(Object key) {
		int length = this.keyTable.length,
			index = (key.hashCode()& 0x7FFFFFFF) % length;
		Object currentKey;
		while ((currentKey = this.keyTable[index]) != null) {
			if (currentKey.equals(key)) {
				int[] value = this.valueTable[index];
				this.elementSize--;
				this.keyTable[index] = null;
				rehash();
				return value;
			}
			if (++index == length) {
				index = 0;
			}
		}
		return null;
	}

	private void rehash() {

		HashtableOfObjectToIntArray newHashtable = new HashtableOfObjectToIntArray(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;
	}

	@Override
	public String toString() {
		StringBuffer buffer = new StringBuffer();
		Object key;
		for (int i = 0, length = this.keyTable.length; i < length; i++) {
			if ((key = this.keyTable[i]) != null) {
				buffer.append(key).append(" -> "); //$NON-NLS-1$
				int[] ints = this.valueTable[i];
				buffer.append('[');
				if (ints != null) {
					for (int j = 0, max = ints.length; j < max; j++) {
						if (j > 0) {
							buffer.append(',');
						}
						buffer.append(ints[j]);
					}
				}
				buffer.append("]\n"); //$NON-NLS-1$
			}
		}
		return String.valueOf(buffer);
	}
}