001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: DTMSafeStringPool.java 468653 2006-10-28 07:07:05Z minchau $
020     */
021    
022    package org.apache.xml.dtm.ref;
023    
024    
025    /** <p>Like DTMStringPool, but threadsafe. It's been proposed that DTMs
026     * share their string pool(s); that raises threadsafety issues which
027     * this addresses. Of course performance is inferior to that of the
028     * bare-bones version.</p>
029     *
030     * <p>Status: Passed basic test in main().</p>
031     * */
032    public class DTMSafeStringPool
033    extends DTMStringPool
034    {
035      public synchronized void removeAllElements()
036        {
037          super.removeAllElements();
038        }
039    
040      /** @return string whose value is uniquely identified by this integer index.
041       * @throws java.lang.ArrayIndexOutOfBoundsException
042       *  if index doesn't map to a string.
043       * */ 
044      public synchronized String indexToString(int i)
045        throws java.lang.ArrayIndexOutOfBoundsException
046        {
047          return super.indexToString(i);
048        }
049    
050      /** @return integer index uniquely identifying the value of this string. */ 
051      public synchronized int stringToIndex(String s)
052        {
053          return super.stringToIndex(s);
054        }
055    
056      /** Command-line unit test driver. This test relies on the fact that
057       * this version of the pool assigns indices consecutively, starting
058       * from zero, as new unique strings are encountered.
059       */
060      public static void main(String[] args)
061      {
062        String[] word={
063          "Zero","One","Two","Three","Four","Five",
064          "Six","Seven","Eight","Nine","Ten",
065          "Eleven","Twelve","Thirteen","Fourteen","Fifteen",
066          "Sixteen","Seventeen","Eighteen","Nineteen","Twenty",
067          "Twenty-One","Twenty-Two","Twenty-Three","Twenty-Four",
068          "Twenty-Five","Twenty-Six","Twenty-Seven","Twenty-Eight",
069          "Twenty-Nine","Thirty","Thirty-One","Thirty-Two",
070          "Thirty-Three","Thirty-Four","Thirty-Five","Thirty-Six",
071          "Thirty-Seven","Thirty-Eight","Thirty-Nine"};
072    
073        DTMStringPool pool=new DTMSafeStringPool();
074    
075        System.out.println("If no complaints are printed below, we passed initial test.");
076    
077        for(int pass=0;pass<=1;++pass)
078          {
079            int i;
080    
081            for(i=0;i<word.length;++i)
082              {
083                int j=pool.stringToIndex(word[i]);
084                if(j!=i)
085                  System.out.println("\tMismatch populating pool: assigned "+
086                                     j+" for create "+i);
087              }
088    
089            for(i=0;i<word.length;++i)
090              {
091                int j=pool.stringToIndex(word[i]);
092                if(j!=i)
093                  System.out.println("\tMismatch in stringToIndex: returned "+
094                                     j+" for lookup "+i);
095              }
096    
097            for(i=0;i<word.length;++i)
098              {
099                String w=pool.indexToString(i);
100                if(!word[i].equals(w))
101                  System.out.println("\tMismatch in indexToString: returned"+
102                                     w+" for lookup "+i);
103              }
104            
105            pool.removeAllElements();
106            
107            System.out.println("\nPass "+pass+" complete\n");
108          } // end pass loop
109      }
110    } // DTMSafeStringPool