/*
* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: CustomStringPool.java,v 1.2.4.1 2005/09/15 08:14:59 suresh_emailid Exp $
*/
package com.sun.org.apache.xml.internal.dtm.ref;
import java.util.Hashtable;
/** <p>CustomStringPool is an example of appliction provided data structure
* for a DTM implementation to hold symbol references, e.g. elelment names.
* It will follow the DTMDStringPool interface and use two simple methods
* indexToString(int i) and stringToIndex(Sring s) to map between a set of
* string values and a set of integer index values. Therefore, an application
* may improve DTM processing speed by substituting the DTM symbol resolution
* tables with application specific quick symbol resolution tables.</p>
*
* %REVIEW% The only difference between this an DTMStringPool seems to be that
* it uses a java.lang.Hashtable full of Integers rather than implementing its
* own hashing. Joe deliberately avoided that approach when writing
* DTMStringPool, since it is both much more memory-hungry and probably slower
* -- especially in JDK 1.1.x, where Hashtable is synchronized. We need to
* either justify this implementation or discard it.
*
* <p>Status: In progress, under discussion.</p>
* */
public class CustomStringPool extends DTMStringPool {
//final Vector m_intToString;
//static final int HASHPRIME=101;
//int[] m_hashStart=new int[HASHPRIME];
final Hashtable m_stringToInt = new Hashtable();
public static final int NULL=-1;
public CustomStringPool()
{
super();
/*m_intToString=new Vector();
System.out.println("In constructor m_intToString is " +
((null == m_intToString) ? "null" : "not null"));*/
//m_stringToInt=new Hashtable();
//removeAllElements();
}
public void removeAllElements()
{
m_intToString.removeAllElements();
if (m_stringToInt != null)
m_stringToInt.clear();
}
/** @return string whose value is uniquely identified by this integer index.
* @throws java.lang.ArrayIndexOutOfBoundsException
* if index doesn't map to a string.
* */
public String indexToString(int i)
throws java.lang.ArrayIndexOutOfBoundsException
{
return(String) m_intToString.elementAt(i);
}
/** @return integer index uniquely identifying the value of this string. */
public int stringToIndex(String s)
{
if (s==null) return NULL;
Integer iobj=(Integer)m_stringToInt.get(s);
if (iobj==null) {
m_intToString.addElement(s);
iobj=new Integer(m_intToString.size());
m_stringToInt.put(s,iobj);
}
return iobj.intValue();
}
}