/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999,2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xerces" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, International
* Business Machines, Inc., http://www.apache.org. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xml.dtm.ref;
import java.util.Vector;
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();
}
}