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/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.HashMap;
import java.util.Map;
/**
* CustomStringPool is an example of an application-provided data structure for a
* DTM implementation to hold symbol references, e.g. element names. It will
* follow the DTMStringPool interface and use two simple methods
* indexToString(int i) and stringToIndex(String 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.
*
*/
public class CustomStringPool extends DTMStringPool {
final Map<String, Integer> m_stringToInt = new HashMap<>();
public static final int NULL = -1;
public CustomStringPool() {
super();
}
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.
*/
@Override
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.
*/
@Override
public int stringToIndex(String s) {
if (s == null) {
return NULL;
}
Integer iobj = m_stringToInt.get(s);
if (iobj == null) {
m_intToString.addElement(s);
iobj = m_intToString.size();
m_stringToInt.put(s, iobj);
}
return iobj;
}
}
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