1 /*
2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3  */
4 /*
5  * Licensed to the Apache Software Foundation (ASF) under one or more
6  * contributor license agreements.  See the NOTICE file distributed with
7  * this work for additional information regarding copyright ownership.
8  * The ASF licenses this file to You under the Apache License, Version 2.0
9  * (the "License"); you may not use this file except in compliance with
10  * the License.  You may obtain a copy of the License at
11  *
12  *      http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20 
21 package com.sun.org.apache.xpath.internal.functions;
22 
23 import com.sun.org.apache.xml.internal.dtm.DTM;
24 import com.sun.org.apache.xml.internal.dtm.DTMIterator;
25 import com.sun.org.apache.xml.internal.utils.QName;
26 import com.sun.org.apache.xpath.internal.XPathContext;
27 import com.sun.org.apache.xpath.internal.axes.SubContextList;
28 import com.sun.org.apache.xpath.internal.compiler.Compiler;
29 import com.sun.org.apache.xpath.internal.objects.XNumber;
30 import com.sun.org.apache.xpath.internal.objects.XObject;
31 import java.util.List;
32 
33 /**
34  * Execute the Position() function.
35  * @xsl.usage advanced
36  * @LastModified: Oct 2017
37  */
38 public class FuncPosition extends Function
39 {
40     static final long serialVersionUID = -9092846348197271582L;
41   private boolean m_isTopLevel;
42 
43   /**
44    * Figure out if we're executing a toplevel expression.
45    * If so, we can't be inside of a predicate.
46    */
postCompileStep(Compiler compiler)47   public void postCompileStep(Compiler compiler)
48   {
49     m_isTopLevel = compiler.getLocationPathDepth() == -1;
50   }
51 
52   /**
53    * Get the position in the current context node list.
54    *
55    * @param xctxt Runtime XPath context.
56    *
57    * @return The current position of the itteration in the context node list,
58    *         or -1 if there is no active context node list.
59    */
getPositionInContextNodeList(XPathContext xctxt)60   public int getPositionInContextNodeList(XPathContext xctxt)
61   {
62 
63     // System.out.println("FuncPosition- entry");
64     // If we're in a predicate, then this will return non-null.
65     SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList();
66 
67     if (null != iter)
68     {
69       int prox = iter.getProximityPosition(xctxt);
70 
71       // System.out.println("FuncPosition- prox: "+prox);
72       return prox;
73     }
74 
75     DTMIterator cnl = xctxt.getContextNodeList();
76 
77     if (null != cnl)
78     {
79       int n = cnl.getCurrentNode();
80       if(n == DTM.NULL)
81       {
82         if(cnl.getCurrentPos() == 0)
83           return 0;
84 
85         // Then I think we're in a sort.  See sort21.xsl. So the iterator has
86         // already been spent, and is not on the node we're processing.
87         // It's highly possible that this is an issue for other context-list
88         // functions.  Shouldn't be a problem for last(), and it shouldn't be
89         // a problem for current().
90         try
91         {
92           cnl = cnl.cloneWithReset();
93         }
94         catch(CloneNotSupportedException cnse)
95         {
96           throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(cnse);
97         }
98         int currentNode = xctxt.getContextNode();
99         // System.out.println("currentNode: "+currentNode);
100         while(DTM.NULL != (n = cnl.nextNode()))
101         {
102           if(n == currentNode)
103             break;
104         }
105       }
106       // System.out.println("n: "+n);
107       // System.out.println("FuncPosition- cnl.getCurrentPos(): "+cnl.getCurrentPos());
108       return cnl.getCurrentPos();
109     }
110 
111     // System.out.println("FuncPosition - out of guesses: -1");
112     return -1;
113   }
114 
115   /**
116    * Execute the function.  The function must return
117    * a valid object.
118    * @param xctxt The current execution context.
119    * @return A valid XObject.
120    *
121    * @throws javax.xml.transform.TransformerException
122    */
execute(XPathContext xctxt)123   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
124   {
125     double pos = (double) getPositionInContextNodeList(xctxt);
126 
127     return new XNumber(pos);
128   }
129 
130   /**
131    * No arguments to process, so this does nothing.
132    */
fixupVariables(List<QName> vars, int globalsSize)133   public void fixupVariables(List<QName> vars, int globalsSize)
134   {
135     // no-op
136   }
137 }
138