KeyIndex


1   /*
2    * Copyright 2001-2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  /*
17   * $Id: KeyIndex.java,v 1.13 2004/02/16 22:54:59 minchau Exp $
18   */
19  
20  package org.apache.xalan.xsltc.dom;
21  
22  import java.util.StringTokenizer  ;
23  
24  import org.apache.xalan.xsltc.DOM;
25  import org.apache.xalan.xsltc.DOMEnhancedForDTM;
26  import org.apache.xalan.xsltc.runtime.Hashtable;
27  import org.apache.xalan.xsltc.util.IntegerArray;
28  import org.apache.xml.dtm.DTM;
29  import org.apache.xml.dtm.DTMAxisIterator;
30  import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
31  
32  /**
33   * @author Morten Jorgensen
34   * @author Santiago Pericas-Geertsen
35   */
36  public class KeyIndex extends DTMAxisIteratorBase {
37  
38      /**
39       * A mapping between values and nodesets.
40       */
41      private Hashtable _index = new Hashtable();
42  
43      /**
44       * The node set associated to the current value passed
45       * to lookupKey();
46       */
47      private IntegerArray _nodes = null;
48  
49      /**
50       * The XSLTC DOM object if this KeyIndex is being used to implement the
51       * id() function.
52       */
53      private DOM        _dom;
54      
55      private DOMEnhancedForDTM    _enhancedDOM;
56  
57      /**
58       * Store position after call to setMark()
59       */
60      private int _markedPosition = 0;
61  
62      public KeyIndex(int dummy) {
63      }
64  
65      public void setRestartable(boolean flag) {
66      }
67  
68      /**
69       * Adds a node to the node list for a given value. Nodes will
70       * always be added in document order.
71       */
72      public void add(Object   value, int node) {
73      IntegerArray nodes;
74      if ((nodes = (IntegerArray) _index.get(value)) == null) {
75          _index.put(value, nodes = new IntegerArray());
76      }
77      nodes.add(node);
78      }
79  
80      /**
81       * Merge the current value's nodeset set by lookupKey() with _nodes.
82       */
83      public void merge(KeyIndex other) {
84      if (other == null) return;
85  
86      if (other._nodes != null) {
87          if (_nodes == null) {
88          _nodes = other._nodes;
89          }
90          else {
91          _nodes.merge(other._nodes);
92          }
93      }
94      }
95  
96      /**
97       * This method must be called by the code generated by the id() function
98       * prior to returning the node iterator. The lookup code for key() and
99       * id() differ in the way the lookup value can be whitespace separated
100      * list of tokens for the id() function, but a single string for the
101      * key() function.
102      */
103     public void lookupId(Object   value) {
104     // Clear _nodes array
105     _nodes = null;
106 
107     final StringTokenizer   values = new StringTokenizer  ((String  ) value);
108     while (values.hasMoreElements()) {
109             final String   token = (String  ) values.nextElement();
110         IntegerArray nodes = (IntegerArray) _index.get(token);
111 
112             if (nodes == null && _enhancedDOM != null
113                 && _enhancedDOM.hasDOMSource()) {
114                 nodes = getDOMNodeById(token);
115             }
116 
117         if (nodes == null) continue;
118 
119         if (_nodes == null) {
120         _nodes = nodes;
121         }
122         else {
123         _nodes.merge(nodes);
124         }
125     }
126     }
127 
128     /**
129      * Return an IntegerArray for the DOM Node which has the given id.
130      * 
131      * @param id The id
132      * @return A IntegerArray representing the Node whose id is the given value.
133      */
134     public IntegerArray getDOMNodeById(String   id) {
135         IntegerArray nodes = null;
136         if (_enhancedDOM != null) {
137             int ident = _enhancedDOM.getElementById(id);
138             if (ident != DTM.NULL) {
139             nodes = new IntegerArray();
140             _index.put(id, nodes);
141         nodes.add(ident);
142             }
143         }
144         return nodes;   
145     }
146     
147     /**
148      * This method must be called by the code generated by the key() function
149      * prior to returning the node iterator.
150      */
151     public void lookupKey(Object   value) {
152     _nodes = (IntegerArray) _index.get(value);
153     _position = 0;
154     }
155 
156     /** 
157      * Callers should not call next() after it returns END.
158      */
159     public int next() {
160     if (_nodes == null) return DTMAxisIterator.END;
161 
162     return (_position < _nodes.cardinality()) ? 
163         _dom.getNodeHandle(_nodes.at(_position++)) : DTMAxisIterator.END;
164     }
165 
166     public int containsID(int node, Object   value) { 
167     final String   string = (String  )value;
168     if (string.indexOf(' ') > -1) {
169         final StringTokenizer   values = new StringTokenizer  (string);
170 
171         while (values.hasMoreElements()) {
172                 final String   token = (String  ) values.nextElement();
173         IntegerArray nodes = (IntegerArray) _index.get(token);
174 
175         if (nodes == null && _enhancedDOM != null
176                     && _enhancedDOM.hasDOMSource()) {
177             nodes = getDOMNodeById(token);  
178         }
179         if (nodes != null && nodes.indexOf(node) >= 0) {
180             return 1;
181         }
182         }
183         return 0;
184     }
185     else {
186         IntegerArray nodes = (IntegerArray) _index.get(value);
187             if (nodes == null && _enhancedDOM != null && _enhancedDOM.hasDOMSource()) {
188                 nodes = getDOMNodeById(string);
189             }
190         return (nodes != null && nodes.indexOf(node) >= 0) ? 1 : 0;
191     }
192     }
193 
194     public int containsKey(int node, Object   value) { 
195     final IntegerArray nodes = (IntegerArray) _index.get(value);
196     return (nodes != null && nodes.indexOf(node) >= 0) ? 1 : 0;
197     }
198 
199     /**
200      * Resets the iterator to the last start node.
201      */
202     public DTMAxisIterator reset() {
203     _position = 0;
204     return this;
205     }
206 
207     /**
208      * Returns the number of elements in this iterator.
209      */
210     public int getLast() {
211     return (_nodes == null) ? 0 : _nodes.cardinality();
212     }
213 
214     /**
215      * Returns the position of the current node in the set.
216      */
217     public int getPosition() {
218     return _position;
219     }
220 
221     /**
222      * Remembers the current node for the next call to gotoMark().
223      */
224     public void setMark() {
225     _markedPosition = _position;
226     }
227 
228     /**
229      * Restores the current node remembered by setMark().
230      */
231     public void gotoMark() {
232     _position = _markedPosition;
233     }
234 
235     /** 
236      * Set start to END should 'close' the iterator, 
237      * i.e. subsequent call to next() should return END.
238      */
239     public DTMAxisIterator setStartNode(int start) {
240     if (start == DTMAxisIterator.END) {
241         _nodes = null;
242     }
243     else if (_nodes != null) {
244         _position = 0;
245     }
246     return (DTMAxisIterator) this;
247     }
248     
249     /** 
250      * Get start to END should 'close' the iterator, 
251      * i.e. subsequent call to next() should return END.
252      */
253     public int getStartNode() {      
254         return 0;
255     }
256 
257     /**
258      * True if this iterator has a reversed axis.
259      */
260     public boolean isReverse() {
261     return(false);
262     }
263 
264     /**
265      * Returns a deep copy of this iterator.
266      */
267     public DTMAxisIterator cloneIterator() {
268     KeyIndex other = new KeyIndex(0);
269     other._index = _index;
270     other._nodes = _nodes;
271     other._position = _position;
272     return (DTMAxisIterator) other;
273     }
274     
275     public void setDom(DOM dom) {
276         _dom = dom;
277         if (dom instanceof DOMEnhancedForDTM) {
278             _enhancedDOM = (DOMEnhancedForDTM)dom;
279         }
280         else if (dom instanceof DOMAdapter) {
281             DOM idom = ((DOMAdapter)dom).getDOMImpl();
282             if (idom instanceof DOMEnhancedForDTM) {
283                 _enhancedDOM = (DOMEnhancedForDTM)idom;
284             }
285         }
286     }
287 }
288
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