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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one
      3  * or more contributor license agreements. See the NOTICE file
      4  * distributed with this work for additional information
      5  * regarding copyright ownership. The ASF licenses this file
      6  * to you under the Apache License, Version 2.0 (the  "License");
      7  * you may not use this file except in compliance with the License.
      8  * You may obtain a copy of the License at
      9  *
     10  *     http://www.apache.org/licenses/LICENSE-2.0
     11  *
     12  * Unless required by applicable law or agreed to in writing, software
     13  * distributed under the License is distributed on an "AS IS" BASIS,
     14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15  * See the License for the specific language governing permissions and
     16  * limitations under the License.
     17  */
     18 /*
     19  * $Id: KeyManager.java 468645 2006-10-28 06:57:24Z minchau $
     20  */
     21 package org.apache.xalan.transformer;
     22 
     23 import java.util.Vector;
     24 
     25 import org.apache.xalan.templates.ElemTemplateElement;
     26 import org.apache.xml.utils.PrefixResolver;
     27 import org.apache.xml.utils.QName;
     28 import org.apache.xml.utils.XMLString;
     29 import org.apache.xpath.XPathContext;
     30 import org.apache.xpath.objects.XNodeSet;
     31 
     32 /**
     33  * This class manages the key tables.
     34  */
     35 public class KeyManager
     36 {
     37 
     38   /**
     39    * Table of tables of element keys.
     40    * @see org.apache.xalan.transformer.KeyTable
     41    */
     42   private transient Vector m_key_tables = null;
     43 
     44   /**
     45    * Given a valid element key, return the corresponding node list.
     46    *
     47    * @param xctxt The XPath runtime state
     48    * @param doc The document node
     49    * @param name The key element name
     50    * @param ref The key value we're looking for
     51    * @param nscontext The prefix resolver for the execution context
     52    *
     53    * @return A nodelist of nodes mathing the given key
     54    *
     55    * @throws javax.xml.transform.TransformerException
     56    */
     57   public XNodeSet getNodeSetDTMByKey(
     58           XPathContext xctxt, int doc, QName name, XMLString ref, PrefixResolver nscontext)
     59             throws javax.xml.transform.TransformerException
     60   {
     61 
     62     XNodeSet nl = null;
     63     ElemTemplateElement template = (ElemTemplateElement) nscontext;  // yuck -sb
     64 
     65     if ((null != template)
     66             && null != template.getStylesheetRoot().getKeysComposed())
     67     {
     68       boolean foundDoc = false;
     69 
     70       if (null == m_key_tables)
     71       {
     72         m_key_tables = new Vector(4);
     73       }
     74       else
     75       {
     76         int nKeyTables = m_key_tables.size();
     77 
     78         for (int i = 0; i < nKeyTables; i++)
     79         {
     80           KeyTable kt = (KeyTable) m_key_tables.elementAt(i);
     81 
     82           if (kt.getKeyTableName().equals(name) && doc == kt.getDocKey())
     83           {
     84             nl = kt.getNodeSetDTMByKey(name, ref);
     85 
     86             if (nl != null)
     87             {
     88               foundDoc = true;
     89 
     90               break;
     91             }
     92           }
     93         }
     94       }
     95 
     96       if ((null == nl) &&!foundDoc /* && m_needToBuildKeysTable */)
     97       {
     98         KeyTable kt =
     99           new KeyTable(doc, nscontext, name,
    100                        template.getStylesheetRoot().getKeysComposed(),
    101                        xctxt);
    102 
    103         m_key_tables.addElement(kt);
    104 
    105         if (doc == kt.getDocKey())
    106         {
    107           foundDoc = true;
    108           nl = kt.getNodeSetDTMByKey(name, ref);
    109         }
    110       }
    111     }
    112 
    113     return nl;
    114   }
    115 }
    116