code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the  "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id$
   */
  package org.apache.xalan.transformer;
  
  import java.util.Enumeration;
  import java.util.Stack;
  
  import org.apache.xml.dtm.DTMIterator;
  import org.apache.xml.utils.BoolStack;
  import org.apache.xml.utils.IntStack;
  import org.apache.xml.utils.NamespaceSupport2;
  import org.apache.xml.utils.NodeVector;
  import org.apache.xml.utils.ObjectStack;
  import org.apache.xpath.VariableStack;
  import org.apache.xpath.XPathContext;
  
  import org.xml.sax.helpers.NamespaceSupport;
  
  import org.apache.xml.serializer.NamespaceMappings;
  import org.apache.xml.serializer.SerializationHandler;
  /**
   * This class holds a "snapshot" of it's current transformer state,
   * which can later be restored.
   *
   * This only saves state which can change over the course of the side-effect-free
   * (i.e. no extensions that call setURIResolver, etc.).
   * 
   * @deprecated  It doesn't look like this code, which is for tooling, has
   * functioned propery for a while, so it doesn't look like it is being used.
   */
  class TransformSnapshotImpl implements TransformSnapshot
  {
  
    /**
     * The stack of Variable stack frames.
     */
    private VariableStack m_variableStacks;
  
    /**
     * The stack of <a href="http://www.w3.org/TR/xslt#dt-current-node">current node</a> objects.
     *  Not to be confused with the current node list.  
     */
    private IntStack m_currentNodes;
  
    /** A stack of the current sub-expression nodes. */
    private IntStack m_currentExpressionNodes;
  
    /**
     * The current context node lists stack.
     */
    private Stack m_contextNodeLists;
  
    /**
     * The current context node list.
     */
    private DTMIterator m_contextNodeList;
  
    /**
     * Stack of AxesIterators.
     */
    private Stack m_axesIteratorStack;
  
    /**
     * Is > 0 when we're processing a for-each.
     */
    private BoolStack m_currentTemplateRuleIsNull;
  
    /**
     * A node vector used as a stack to track the current
     * ElemTemplateElement.  Needed for the
     * org.apache.xalan.transformer.TransformState interface,
     * so a tool can discover the calling template. 
     */
    private ObjectStack m_currentTemplateElements;
  
    /**
     * A node vector used as a stack to track the current
     * ElemTemplate that was matched, as well as the node that
     * was matched.  Needed for the
     * org.apache.xalan.transformer.TransformState interface,
     * so a tool can discover the matched template, and matched
     * node. 
     */
    private Stack m_currentMatchTemplates;
  
    /**
     * A node vector used as a stack to track the current
     * ElemTemplate that was matched, as well as the node that
     * was matched.  Needed for the
     * org.apache.xalan.transformer.TransformState interface,
     * so a tool can discover the matched template, and matched
     * node. 
     */
    private NodeVector m_currentMatchNodes;
  
    /**
     * The table of counters for xsl:number support.
     * @see ElemNumber
     */
    private CountersTable m_countersTable;
  
    /**
     * Stack for the purposes of flagging infinite recursion with
     * attribute sets.
     */
    private Stack m_attrSetStack;
  
    /** Indicate whether a namespace context was pushed */
    boolean m_nsContextPushed;
  
    /**
     * Use the SAX2 helper class to track result namespaces.
     */
    private NamespaceMappings m_nsSupport;
  
    /** The number of events queued */
  //  int m_eventCount;
  
    /**
     * Constructor TransformSnapshotImpl
     * Take a snapshot of the currently executing context.
     *
     * @param transformer Non null transformer instance
     * @deprecated  It doesn't look like this code, which is for tooling, has
     * functioned propery for a while, so it doesn't look like it is being used.
     */
    TransformSnapshotImpl(TransformerImpl transformer)
    {
  
      try
      {
  
        // Are all these clones deep enough?
        SerializationHandler rtf = transformer.getResultTreeHandler();
  
        {
          // save serializer fields
          m_nsSupport = (NamespaceMappings)rtf.getNamespaceMappings().clone();
          
          // Do other fields need to be saved/restored?
        }
   
        XPathContext xpc = transformer.getXPathContext();
  
        m_variableStacks = (VariableStack) xpc.getVarStack().clone();
        m_currentNodes = (IntStack) xpc.getCurrentNodeStack().clone();
        m_currentExpressionNodes =
          (IntStack) xpc.getCurrentExpressionNodeStack().clone();
        m_contextNodeLists = (Stack) xpc.getContextNodeListsStack().clone();
  
        if (!m_contextNodeLists.empty())
          m_contextNodeList =
            (DTMIterator) xpc.getContextNodeList().clone();
  
        m_axesIteratorStack = (Stack) xpc.getAxesIteratorStackStacks().clone();
        m_currentTemplateRuleIsNull =
          (BoolStack) transformer.m_currentTemplateRuleIsNull.clone();
        m_currentTemplateElements =
          (ObjectStack) transformer.m_currentTemplateElements.clone();
        m_currentMatchTemplates =
          (Stack) transformer.m_currentMatchTemplates.clone();
        m_currentMatchNodes =
          (NodeVector) transformer.m_currentMatchedNodes.clone();
        m_countersTable =
          (CountersTable) transformer.getCountersTable().clone();
  
        if (transformer.m_attrSetStack != null)
          m_attrSetStack = (Stack) transformer.m_attrSetStack.clone();
      }
      catch (CloneNotSupportedException cnse)
      {
        throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
      }
    }
  
    /**
     * This will reset the stylesheet to a given execution context
     * based on some previously taken snapshot where we can then start execution 
     *
     * @param transformer Non null transformer instance
     * 
     * @deprecated  It doesn't look like this code, which is for tooling, has
     * functioned propery for a while, so it doesn't look like it is being used.
     */
    void apply(TransformerImpl transformer)
    {
  
      try
      {
  
        // Are all these clones deep enough?
        SerializationHandler rtf = transformer.getResultTreeHandler();
  
        if (rtf != null)
        {
          // restore serializer fields
           rtf.setNamespaceMappings((NamespaceMappings)m_nsSupport.clone());
        }
  
        XPathContext xpc = transformer.getXPathContext();
  
        xpc.setVarStack((VariableStack) m_variableStacks.clone());
        xpc.setCurrentNodeStack((IntStack) m_currentNodes.clone());
        xpc.setCurrentExpressionNodeStack(
          (IntStack) m_currentExpressionNodes.clone());
        xpc.setContextNodeListsStack((Stack) m_contextNodeLists.clone());
  
        if (m_contextNodeList != null)
          xpc.pushContextNodeList((DTMIterator) m_contextNodeList.clone());
  
        xpc.setAxesIteratorStackStacks((Stack) m_axesIteratorStack.clone());
  
        transformer.m_currentTemplateRuleIsNull =
          (BoolStack) m_currentTemplateRuleIsNull.clone();
        transformer.m_currentTemplateElements =
          (ObjectStack) m_currentTemplateElements.clone();
        transformer.m_currentMatchTemplates =
          (Stack) m_currentMatchTemplates.clone();
        transformer.m_currentMatchedNodes =
          (NodeVector) m_currentMatchNodes.clone();
        transformer.m_countersTable = (CountersTable) m_countersTable.clone();
  
        if (m_attrSetStack != null)
          transformer.m_attrSetStack = (Stack) m_attrSetStack.clone();
      }
      catch (CloneNotSupportedException cnse)
      {
        throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
      }
    }
  }
  