/*******************************************************************************
* 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;
import org.eclipse.jdt.internal.compiler.lookup.PackageBinding;
public final class HashtableOfPackage {
// to avoid using Enumerations, walk the individual tables skipping nulls
public char[] keyTable[];
public PackageBinding valueTable[];
public int elementSize; // number of elements in the table
int threshold;
public HashtableOfPackage() {
this(3); // usually not very large
}
public HashtableOfPackage(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 PackageBinding[extraRoom];
}
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 PackageBinding 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 null;
}
public PackageBinding put(char[] key, PackageBinding 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;
}
private void rehash() {
HashtableOfPackage newHashtable = new HashtableOfPackage(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 = ""; //$NON-NLS-1$
PackageBinding pkg;
for (int i = 0, length = this.valueTable.length; i < length; i++)
if ((pkg = this.valueTable[i]) != null)
s += pkg.toString() + "\n"; //$NON-NLS-1$
return s;
}
}