TransformSnapshotImpl


1   /*
2    * Copyright 1999-2004 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: TransformSnapshotImpl.java,v 1.11 2004/02/16 20:41:29 minchau Exp $
18   */
19  package org.apache.xalan.transformer;
20  
21  import java.util.Enumeration  ;
22  import java.util.Stack  ;
23  
24  import org.apache.xml.dtm.DTMIterator;
25  import org.apache.xml.utils.BoolStack;
26  import org.apache.xml.utils.IntStack;
27  import org.apache.xml.utils.NamespaceSupport2;
28  import org.apache.xml.utils.NodeVector;
29  import org.apache.xml.utils.ObjectStack;
30  import org.apache.xpath.VariableStack;
31  import org.apache.xpath.XPathContext;
32  
33  import org.xml.sax.helpers.NamespaceSupport  ;
34  
35  import org.apache.xml.serializer.NamespaceMappings;
36  import org.apache.xml.serializer.SerializationHandler;
37  /**
38   * This class holds a "snapshot" of it's current transformer state,
39   * which can later be restored.
40   *
41   * This only saves state which can change over the course of the side-effect-free
42   * (i.e. no extensions that call setURIResolver, etc.).
43   * 
44   * @deprecated  It doesn't look like this code, which is for tooling, has
45   * functioned propery for a while, so it doesn't look like it is being used.
46   */
47  class TransformSnapshotImpl implements TransformSnapshot
48  {
49  
50    /**
51     * The stack of Variable stack frames.
52     */
53    private VariableStack m_variableStacks;
54  
55    /**
56     * The stack of <a HREF="http://www.w3.org/TR/xslt#dt-current-node">current node</a> objects.
57     *  Not to be confused with the current node list.  
58     */
59    private IntStack m_currentNodes;
60  
61    /** A stack of the current sub-expression nodes. */
62    private IntStack m_currentExpressionNodes;
63  
64    /**
65     * The current context node lists stack.
66     */
67    private Stack   m_contextNodeLists;
68  
69    /**
70     * The current context node list.
71     */
72    private DTMIterator m_contextNodeList;
73  
74    /**
75     * Stack of AxesIterators.
76     */
77    private Stack   m_axesIteratorStack;
78  
79    /**
80     * Is > 0 when we're processing a for-each.
81     */
82    private BoolStack m_currentTemplateRuleIsNull;
83  
84    /**
85     * A node vector used as a stack to track the current
86     * ElemTemplateElement.  Needed for the
87     * org.apache.xalan.transformer.TransformState interface,
88     * so a tool can discover the calling template. 
89     */
90    private ObjectStack m_currentTemplateElements;
91  
92    /**
93     * A node vector used as a stack to track the current
94     * ElemTemplate that was matched, as well as the node that
95     * was matched.  Needed for the
96     * org.apache.xalan.transformer.TransformState interface,
97     * so a tool can discover the matched template, and matched
98     * node. 
99     */
100   private Stack   m_currentMatchTemplates;
101 
102   /**
103    * A node vector used as a stack to track the current
104    * ElemTemplate that was matched, as well as the node that
105    * was matched.  Needed for the
106    * org.apache.xalan.transformer.TransformState interface,
107    * so a tool can discover the matched template, and matched
108    * node. 
109    */
110   private NodeVector m_currentMatchNodes;
111 
112   /**
113    * The table of counters for xsl:number support.
114    * @see ElemNumber
115    */
116   private CountersTable m_countersTable;
117 
118   /**
119    * Stack for the purposes of flagging infinite recursion with
120    * attribute sets.
121    */
122   private Stack   m_attrSetStack;
123 
124   /** Indicate whether a namespace context was pushed */
125   boolean m_nsContextPushed;
126 
127   /**
128    * Use the SAX2 helper class to track result namespaces.
129    */
130   private NamespaceMappings m_nsSupport;
131 
132   /** The number of events queued */
133 //  int m_eventCount;
134 
135   /**
136    * Constructor TransformSnapshotImpl
137    * Take a snapshot of the currently executing context.
138    *
139    * @param transformer Non null transformer instance
140    * @deprecated  It doesn't look like this code, which is for tooling, has
141    * functioned propery for a while, so it doesn't look like it is being used.
142    */
143   TransformSnapshotImpl(TransformerImpl transformer)
144   {
145 
146     try
147     {
148 
149       // Are all these clones deep enough?
150       SerializationHandler rtf = transformer.getResultTreeHandler();
151 
152       {
153         // save serializer fields
154         m_nsSupport = (NamespaceMappings)rtf.getNamespaceMappings().clone();
155         
156         // Do other fields need to be saved/restored?
157       }
158  
159       XPathContext xpc = transformer.getXPathContext();
160 
161       m_variableStacks = (VariableStack) xpc.getVarStack().clone();
162       m_currentNodes = (IntStack) xpc.getCurrentNodeStack().clone();
163       m_currentExpressionNodes =
164         (IntStack) xpc.getCurrentExpressionNodeStack().clone();
165       m_contextNodeLists = (Stack  ) xpc.getContextNodeListsStack().clone();
166 
167       if (!m_contextNodeLists.empty())
168         m_contextNodeList =
169           (DTMIterator) xpc.getContextNodeList().clone();
170 
171       m_axesIteratorStack = (Stack  ) xpc.getAxesIteratorStackStacks().clone();
172       m_currentTemplateRuleIsNull =
173         (BoolStack) transformer.m_currentTemplateRuleIsNull.clone();
174       m_currentTemplateElements =
175         (ObjectStack) transformer.m_currentTemplateElements.clone();
176       m_currentMatchTemplates =
177         (Stack  ) transformer.m_currentMatchTemplates.clone();
178       m_currentMatchNodes =
179         (NodeVector) transformer.m_currentMatchedNodes.clone();
180       m_countersTable =
181         (CountersTable) transformer.getCountersTable().clone();
182 
183       if (transformer.m_attrSetStack != null)
184         m_attrSetStack = (Stack  ) transformer.m_attrSetStack.clone();
185     }
186     catch (CloneNotSupportedException   cnse)
187     {
188       throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
189     }
190   }
191 
192   /**
193    * This will reset the stylesheet to a given execution context
194    * based on some previously taken snapshot where we can then start execution 
195    *
196    * @param transformer Non null transformer instance
197    * 
198    * @deprecated  It doesn't look like this code, which is for tooling, has
199    * functioned propery for a while, so it doesn't look like it is being used.
200    */
201   void apply(TransformerImpl transformer)
202   {
203 
204     try
205     {
206 
207       // Are all these clones deep enough?
208       SerializationHandler rtf = transformer.getResultTreeHandler();
209 
210       if (rtf != null)
211       {
212         // restore serializer fields
213          rtf.setNamespaceMappings((NamespaceMappings)m_nsSupport.clone());
214       }
215 
216       XPathContext xpc = transformer.getXPathContext();
217 
218       xpc.setVarStack((VariableStack) m_variableStacks.clone());
219       xpc.setCurrentNodeStack((IntStack) m_currentNodes.clone());
220       xpc.setCurrentExpressionNodeStack(
221         (IntStack) m_currentExpressionNodes.clone());
222       xpc.setContextNodeListsStack((Stack  ) m_contextNodeLists.clone());
223 
224       if (m_contextNodeList != null)
225         xpc.pushContextNodeList((DTMIterator) m_contextNodeList.clone());
226 
227       xpc.setAxesIteratorStackStacks((Stack  ) m_axesIteratorStack.clone());
228 
229       transformer.m_currentTemplateRuleIsNull =
230         (BoolStack) m_currentTemplateRuleIsNull.clone();
231       transformer.m_currentTemplateElements =
232         (ObjectStack) m_currentTemplateElements.clone();
233       transformer.m_currentMatchTemplates =
234         (Stack  ) m_currentMatchTemplates.clone();
235       transformer.m_currentMatchedNodes =
236         (NodeVector) m_currentMatchNodes.clone();
237       transformer.m_countersTable = (CountersTable) m_countersTable.clone();
238 
239       if (m_attrSetStack != null)
240         transformer.m_attrSetStack = (Stack  ) m_attrSetStack.clone();
241     }
242     catch (CloneNotSupportedException   cnse)
243     {
244       throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
245     }
246   }
247 }
248
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags