/*******************************************************************************
* 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;
import org.eclipse.jdt.core.compiler.CharOperation;
/**
* Hashtable of {char[] --> int}
*/
public final class HashtableOfIntValues implements Cloneable {
public static final int NO_VALUE= Integer.MIN_VALUE;
// to avoid using Enumerations, walk the individual tables skipping nulls
public char[] keyTable[];
public int valueTable[];
public int elementSize; // number of elements in the table
int threshold;
public HashtableOfIntValues() {
this(13);
}
public HashtableOfIntValues(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 char[extraRoom][];
this.valueTable= new int[extraRoom];
}
public Object clone() throws CloneNotSupportedException {
HashtableOfIntValues result= (HashtableOfIntValues)super.clone();
result.elementSize= this.elementSize;
result.threshold= this.threshold;
int length= this.keyTable.length;
result.keyTable= new char[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(char[] key) {
int length= this.keyTable.length, index= CharOperation.hashCode(key) % length;
int keyLength= key.length;
char[] currentKey;
while ((currentKey= this.keyTable[index]) != null) {
if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
return true;
if (++index == length) {
index= 0;
}
}
return false;
}
public int get(char[] key) {
int length= this.keyTable.length, index= CharOperation.hashCode(key) % length;
int keyLength= key.length;
char[] currentKey;
while ((currentKey= this.keyTable[index]) != null) {
if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
return this.valueTable[index];
if (++index == length) {
index= 0;
}
}
return NO_VALUE;
}
public int put(char[] key, int value) {
int length= this.keyTable.length, index= CharOperation.hashCode(key) % length;
int keyLength= key.length;
char[] currentKey;
while ((currentKey= this.keyTable[index]) != null) {
if (currentKey.length == keyLength && CharOperation.equals(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;
}
public int removeKey(char[] key) {
int length= this.keyTable.length, index= CharOperation.hashCode(key) % length;
int keyLength= key.length;
char[] currentKey;
while ((currentKey= this.keyTable[index]) != null) {
if (currentKey.length == keyLength && CharOperation.equals(currentKey, key)) {
int value= this.valueTable[index];
this.elementSize--;
this.keyTable[index]= null;
this.valueTable[index]= NO_VALUE;
rehash();
return value;
}
if (++index == length) {
index= 0;
}
}
return NO_VALUE;
}
private void rehash() {
HashtableOfIntValues newHashtable= new HashtableOfIntValues(this.elementSize * 2); // double the number of expected elements
char[] 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;
}
public String toString() {
String s= ""; //$NON-NLS-1$
char[] key;
for (int i= 0, length= this.valueTable.length; i < length; i++)
if ((key= this.keyTable[i]) != null)
s+= new String(key) + " -> " + this.valueTable[i] + "\n"; //$NON-NLS-2$ //$NON-NLS-1$
return s;
}
}