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/*
 * 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: DTMDefaultBaseTraversers.java 468653 2006-10-28 07:07:05Z minchau $
 */
package org.apache.xml.dtm.ref;

import org.apache.xml.dtm.*;

import javax.xml.transform.Source;

import org.apache.xml.utils.XMLStringFactory;

import org.apache.xml.res.XMLErrorResources;
import org.apache.xml.res.XMLMessages;

/**
 * This class implements the traversers for DTMDefaultBase.
 *
 * PLEASE NOTE that the public interface for all traversers should be
 * in terms of DTM Node Handles... but they may use the internal node
 * identity indices within their logic, for efficiency's sake. Be very
 * careful to avoid confusing these when maintaining this code.
 * */
public abstract class DTMDefaultBaseTraversers extends DTMDefaultBase
{

  /**
   * Construct a DTMDefaultBaseTraversers object from a DOM node.
   *
   * @param mgr The DTMManager who owns this DTM.
   * @param source The object that is used to specify the construction source.
   * @param dtmIdentity The DTM identity ID for this DTM.
   * @param whiteSpaceFilter The white space filter for this DTM, which may
   *                         be null.
   * @param xstringfactory The factory to use for creating XMLStrings.
   * @param doIndexing true if the caller considers it worth it to use
   *                   indexing schemes.
   */
  public DTMDefaultBaseTraversers(DTMManager mgr, Source source,
                                  int dtmIdentity,
                                  DTMWSFilter whiteSpaceFilter,
                                  XMLStringFactory xstringfactory,
                                  boolean doIndexing)
  {
    super(mgr, source, dtmIdentity, whiteSpaceFilter, xstringfactory,
          doIndexing);
  }

  /**
   * Construct a DTMDefaultBaseTraversers object from a DOM node.
   *
   * @param mgr The DTMManager who owns this DTM.
   * @param source The object that is used to specify the construction source.
   * @param dtmIdentity The DTM identity ID for this DTM.
   * @param whiteSpaceFilter The white space filter for this DTM, which may
   *                         be null.
   * @param xstringfactory The factory to use for creating XMLStrings.
   * @param doIndexing true if the caller considers it worth it to use
   *                   indexing schemes.
   * @param blocksize The block size of the DTM.
   * @param usePrevsib true if we want to build the previous sibling node array.
   * @param newNameTable true if we want to use a new ExpandedNameTable for this DTM.
   */
  public DTMDefaultBaseTraversers(DTMManager mgr, Source source,
                                  int dtmIdentity,
                                  DTMWSFilter whiteSpaceFilter,
                                  XMLStringFactory xstringfactory,
                                  boolean doIndexing,
                                  int blocksize,
                                  boolean usePrevsib,
                                  boolean newNameTable)
  {
    super(mgr, source, dtmIdentity, whiteSpaceFilter, xstringfactory,
          doIndexing, blocksize, usePrevsib, newNameTable);
  }

  /**
   * This returns a stateless "traverser", that can navigate
   * over an XPath axis, though perhaps not in document order.
   *
   * @param axis One of Axes.ANCESTORORSELF, etc.
   *
   * @return A DTMAxisTraverser, or null if the given axis isn't supported.
   */
  public DTMAxisTraverser getAxisTraverser(final int axis)
  {

    DTMAxisTraverser traverser;

    if (null == m_traversers)  // Cache of stateless traversers for this DTM
    {
      m_traversers = new DTMAxisTraverser[Axis.getNamesLength()];
      traverser = null;
    }
    else
    {
      traverser = m_traversers[axis];  // Share/reuse existing traverser

      if (traverser != null)
        return traverser;
    }

    switch (axis)  // Generate new traverser
    {
    case Axis.ANCESTOR :
      traverser = new AncestorTraverser();
      break;
    case Axis.ANCESTORORSELF :
      traverser = new AncestorOrSelfTraverser();
      break;
    case Axis.ATTRIBUTE :
      traverser = new AttributeTraverser();
      break;
    case Axis.CHILD :
      traverser = new ChildTraverser();
      break;
    case Axis.DESCENDANT :
      traverser = new DescendantTraverser();
      break;
    case Axis.DESCENDANTORSELF :
      traverser = new DescendantOrSelfTraverser();
      break;
    case Axis.FOLLOWING :
      traverser = new FollowingTraverser();
      break;
    case Axis.FOLLOWINGSIBLING :
      traverser = new FollowingSiblingTraverser();
      break;
    case Axis.NAMESPACE :
      traverser = new NamespaceTraverser();
      break;
    case Axis.NAMESPACEDECLS :
      traverser = new NamespaceDeclsTraverser();
      break;
    case Axis.PARENT :
      traverser = new ParentTraverser();
      break;
    case Axis.PRECEDING :
      traverser = new PrecedingTraverser();
      break;
    case Axis.PRECEDINGSIBLING :
      traverser = new PrecedingSiblingTraverser();
      break;
    case Axis.SELF :
      traverser = new SelfTraverser();
      break;
    case Axis.ALL :
      traverser = new AllFromRootTraverser();
      break;
    case Axis.ALLFROMNODE :
      traverser = new AllFromNodeTraverser();
      break;
    case Axis.PRECEDINGANDANCESTOR :
      traverser = new PrecedingAndAncestorTraverser();
      break;
    case Axis.DESCENDANTSFROMROOT :
      traverser = new DescendantFromRootTraverser();
      break;
    case Axis.DESCENDANTSORSELFFROMROOT :
      traverser = new DescendantOrSelfFromRootTraverser();
      break;
    case Axis.ROOT :
      traverser = new RootTraverser();
      break;
    case Axis.FILTEREDLIST :
      return null; // Don't want to throw an exception for this one.
    default :
      throw new DTMException(XMLMessages.createXMLMessage(XMLErrorResources.ER_UNKNOWN_AXIS_TYPE, new Object[]{Integer.toString(axis)})); //"Unknown axis traversal type: "+axis);
    }

    if (null == traverser)
      throw new DTMException(XMLMessages.createXMLMessage(XMLErrorResources.ER_AXIS_TRAVERSER_NOT_SUPPORTED, new Object[]{Axis.getNames(axis)}));
      // "Axis traverser not supported: "
      //                       + Axis.names[axis]);

    m_traversers[axis] = traverser;

    return traverser;
  }

  /**
   * Implements traversal of the Ancestor access, in reverse document order.
   */
  private class AncestorTraverser extends DTMAxisTraverser
  {

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node if this iteration.
     * @param current The current node of the iteration.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current)
    {
			return getParent(current);
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {
			// Process using identities
      current = makeNodeIdentity(current);

      while (DTM.NULL != (current = m_parent.elementAt(current)))
      {
        if (m_exptype.elementAt(current) == expandedTypeID)
          return makeNodeHandle(current);
      }

      return NULL;
    }
  }

  /**
   * Implements traversal of the Ancestor access, in reverse document order.
   */
  private class AncestorOrSelfTraverser extends AncestorTraverser
  {

    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  To see if
     * the self node should be processed, use this function.
     *
     * @param context The context node of this traversal.
     *
     * @return the first node in the traversal.
     */
    public int first(int context)
    {
      return context;
    }

    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  To see if
     * the self node should be processed, use this function.  If the context
     * node does not match the expanded type ID, this function will return
     * false.
     *
     * @param context The context node of this traversal.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
			return (getExpandedTypeID(context) == expandedTypeID)
             ? context : next(context, context, expandedTypeID);
    }
  }

  /**
   * Implements traversal of the Attribute access
   */
  private class AttributeTraverser extends DTMAxisTraverser
  {

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current)
    {
      return (context == current)
             ? getFirstAttribute(context) : getNextAttribute(current);
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {

      current = (context == current)
                ? getFirstAttribute(context) : getNextAttribute(current);

      do
      {
        if (getExpandedTypeID(current) == expandedTypeID)
          return current;
      }
      while (DTM.NULL != (current = getNextAttribute(current)));

      return NULL;
    }
  }

  /**
   * Implements traversal of the Ancestor access, in reverse document order.
   */
  private class ChildTraverser extends DTMAxisTraverser
  {
    
    /**
     * Get the next indexed node that matches the expanded type ID.  Before 
     * calling this function, one should first call 
     * {@link #isIndexed(int) isIndexed} to make sure that the index can 
     * contain nodes that match the given expanded type ID.
     *
     * @param axisRoot The root identity of the axis.
     * @param nextPotential The node found must match or occur after this node.
     * @param expandedTypeID The expanded type ID for the request.
     *
     * @return The node ID or NULL if not found.
     */
    protected int getNextIndexed(int axisRoot, int nextPotential,
                                 int expandedTypeID)
    {

      int nsIndex = m_expandedNameTable.getNamespaceID(expandedTypeID);
      int lnIndex = m_expandedNameTable.getLocalNameID(expandedTypeID);

      for (; ; ) 
      {
        int nextID = findElementFromIndex(nsIndex, lnIndex, nextPotential);

        if (NOTPROCESSED != nextID)
        {
          int parentID = m_parent.elementAt(nextID);
          
          // Is it a child?
          if(parentID == axisRoot)
            return nextID;
          
          // If the parent occured before the subtree root, then 
          // we know it is past the child axis.
          if(parentID < axisRoot)
              return NULL;
          
          // Otherwise, it could be a descendant below the subtree root 
          // children, or it could be after the subtree root.  So we have 
          // to climb up until the parent is less than the subtree root, in 
          // which case we return NULL, or until it is equal to the subtree 
          // root, in which case we continue to look.
          do
          {
            parentID = m_parent.elementAt(parentID);
            if(parentID < axisRoot)
              return NULL;
          }
            while(parentID > axisRoot);
          
          // System.out.println("Found node via index: "+first);
          nextPotential = nextID+1;
          continue;
        }

        nextNode();
        
        if(!(m_nextsib.elementAt(axisRoot) == NOTPROCESSED))
          break;
      }

      return DTM.NULL;
    }
        
    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  So to traverse 
     * an axis, the first function must be used to get the first node.
     *
     * 

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * that the traversal starts from. * @return the first node in the traversal. */ public int first(int context) { return getFirstChild(context); } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { if(true) { int identity = makeNodeIdentity(context); int firstMatch = getNextIndexed(identity, _firstch(identity), expandedTypeID); return makeNodeHandle(firstMatch); } else { // %REVIEW% Dead code. Eliminate? for (int current = _firstch(makeNodeIdentity(context)); DTM.NULL != current; current = _nextsib(current)) { if (m_exptype.elementAt(current) == expandedTypeID) return makeNodeHandle(current); } return NULL; } } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return getNextSibling(current); } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { // Process in Identifier space for (current = _nextsib(makeNodeIdentity(current)); DTM.NULL != current; current = _nextsib(current)) { if (m_exptype.elementAt(current) == expandedTypeID) return makeNodeHandle(current); } return NULL; } } /** * Super class for derived classes that want a convenient way to access * the indexing mechanism. */ private abstract class IndexedDTMAxisTraverser extends DTMAxisTraverser { /** * Tell if the indexing is on and the given expanded type ID matches * what is in the indexes. Derived classes should call this before * calling {@link #getNextIndexed(int, int, int) getNextIndexed} method. * * @param expandedTypeID The expanded type ID being requested. * * @return true if it is OK to call the * {@link #getNextIndexed(int, int, int) getNextIndexed} method. */ protected final boolean isIndexed(int expandedTypeID) { return (m_indexing && ExpandedNameTable.ELEMENT == m_expandedNameTable.getType(expandedTypeID)); } /** * Tell if a node is outside the axis being traversed. This method must be * implemented by derived classes, and must be robust enough to handle any * node that occurs after the axis root. * * @param axisRoot The root identity of the axis. * @param identity The node in question. * * @return true if the given node falls outside the axis being traversed. */ protected abstract boolean isAfterAxis(int axisRoot, int identity); /** * Tell if the axis has been fully processed to tell if a the wait for * an arriving node should terminate. This method must be implemented * be a derived class. * * @param axisRoot The root identity of the axis. * * @return true if the axis has been fully processed. */ protected abstract boolean axisHasBeenProcessed(int axisRoot); /** * Get the next indexed node that matches the expanded type ID. Before * calling this function, one should first call * {@link #isIndexed(int) isIndexed} to make sure that the index can * contain nodes that match the given expanded type ID. * * @param axisRoot The root identity of the axis. * @param nextPotential The node found must match or occur after this node. * @param expandedTypeID The expanded type ID for the request. * * @return The node ID or NULL if not found. */ protected int getNextIndexed(int axisRoot, int nextPotential, int expandedTypeID) { int nsIndex = m_expandedNameTable.getNamespaceID(expandedTypeID); int lnIndex = m_expandedNameTable.getLocalNameID(expandedTypeID); while(true) { int next = findElementFromIndex(nsIndex, lnIndex, nextPotential); if (NOTPROCESSED != next) { if (isAfterAxis(axisRoot, next)) return NULL; // System.out.println("Found node via index: "+first); return next; } else if(axisHasBeenProcessed(axisRoot)) break; nextNode(); } return DTM.NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class DescendantTraverser extends IndexedDTMAxisTraverser { /** * Get the first potential identity that can be returned. This should * be overridded by classes that need to return the self node. * * @param identity The node identity of the root context of the traversal. * * @return The first potential node that can be in the traversal. */ protected int getFirstPotential(int identity) { return identity + 1; } /** * Tell if the axis has been fully processed to tell if a the wait for * an arriving node should terminate. * * @param axisRoot The root identity of the axis. * * @return true if the axis has been fully processed. */ protected boolean axisHasBeenProcessed(int axisRoot) { return !(m_nextsib.elementAt(axisRoot) == NOTPROCESSED); } /** * Get the subtree root identity from the handle that was passed in by * the caller. Derived classes may override this to change the root * context of the traversal. * * @param handle handle to the root context. * @return identity of the root of the subtree. */ protected int getSubtreeRoot(int handle) { return makeNodeIdentity(handle); } /** * Tell if this node identity is a descendant. Assumes that * the node info for the element has already been obtained. * * %REVIEW% This is really parentFollowsRootInDocumentOrder ... * which fails if the parent starts after the root ends. * May be sufficient for this class's logic, but misleadingly named! * * @param subtreeRootIdentity The root context of the subtree in question. * @param identity The index number of the node in question. * @return true if the index is a descendant of _startNode. */ protected boolean isDescendant(int subtreeRootIdentity, int identity) { return _parent(identity) >= subtreeRootIdentity; } /** * Tell if a node is outside the axis being traversed. This method must be * implemented by derived classes, and must be robust enough to handle any * node that occurs after the axis root. * * @param axisRoot The root identity of the axis. * @param identity The node in question. * * @return true if the given node falls outside the axis being traversed. */ protected boolean isAfterAxis(int axisRoot, int identity) { // %REVIEW% Is there *any* cheaper way to do this? // Yes. In ID space, compare to axisRoot's successor // (next-sib or ancestor's-next-sib). Probably shallower search. do { if(identity == axisRoot) return false; identity = m_parent.elementAt(identity); } while(identity >= axisRoot); return true; } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { if (isIndexed(expandedTypeID)) { int identity = getSubtreeRoot(context); int firstPotential = getFirstPotential(identity); return makeNodeHandle(getNextIndexed(identity, firstPotential, expandedTypeID)); } return next(context, context, expandedTypeID); } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { int subtreeRootIdent = getSubtreeRoot(context); for (current = makeNodeIdentity(current) + 1; ; current++) { int type = _type(current); // may call nextNode() if (!isDescendant(subtreeRootIdent, current)) return NULL; if (ATTRIBUTE_NODE == type || NAMESPACE_NODE == type) continue; return makeNodeHandle(current); // make handle. } } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { int subtreeRootIdent = getSubtreeRoot(context); current = makeNodeIdentity(current) + 1; if (isIndexed(expandedTypeID)) { return makeNodeHandle(getNextIndexed(subtreeRootIdent, current, expandedTypeID)); } for (; ; current++) { int exptype = _exptype(current); // may call nextNode() if (!isDescendant(subtreeRootIdent, current)) return NULL; if (exptype != expandedTypeID) continue; return makeNodeHandle(current); // make handle. } } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class DescendantOrSelfTraverser extends DescendantTraverser { /** * Get the first potential identity that can be returned, which is the * axis context, in this case. * * @param identity The node identity of the root context of the traversal. * * @return The axis context. */ protected int getFirstPotential(int identity) { return identity; } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. To see if * the self node should be processed, use this function. * * @param context The context node of this traversal. * * @return the first node in the traversal. */ public int first(int context) { return context; } } /** * Implements traversal of the entire subtree, including the root node. */ private class AllFromNodeTraverser extends DescendantOrSelfTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) + 1; ; current++) { // Trickological code: _exptype() has the side-effect of // running nextNode until the specified node has been loaded, // and thus can be used to ensure that incremental construction of // the DTM has gotten this far. Using it just for that side-effect // is quite a kluge... _exptype(current); // make sure it's here. if (!isDescendant(subtreeRootIdent, current)) return NULL; return makeNodeHandle(current); // make handle. } } } /** * Implements traversal of the following access, in document order. */ private class FollowingTraverser extends DescendantTraverser { /** * Get the first of the following. * * @param context The context node of this traversal. This is the point * that the traversal starts from. * @return the first node in the traversal. */ public int first(int context) { // Compute in ID space context=makeNodeIdentity(context); int first; int type = _type(context); if ((DTM.ATTRIBUTE_NODE == type) || (DTM.NAMESPACE_NODE == type)) { context = _parent(context); first = _firstch(context); if (NULL != first) return makeNodeHandle(first); } do { first = _nextsib(context); if (NULL == first) context = _parent(context); } while (NULL == first && NULL != context); return makeNodeHandle(first); } /** * Get the first of the following. * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { // %REVIEW% This looks like it might want shift into identity space // to avoid repeated conversion in the individual functions int first; int type = getNodeType(context); if ((DTM.ATTRIBUTE_NODE == type) || (DTM.NAMESPACE_NODE == type)) { context = getParent(context); first = getFirstChild(context); if (NULL != first) { if (getExpandedTypeID(first) == expandedTypeID) return first; else return next(context, first, expandedTypeID); } } do { first = getNextSibling(context); if (NULL == first) context = getParent(context); else { if (getExpandedTypeID(first) == expandedTypeID) return first; else return next(context, first, expandedTypeID); } } while (NULL == first && NULL != context); return first; } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { // Compute in identity space current=makeNodeIdentity(current); while (true) { current++; // Only works on IDs, not handles. // %REVIEW% Are we using handles or indexes? int type = _type(current); // may call nextNode() if (NULL == type) return NULL; if (ATTRIBUTE_NODE == type || NAMESPACE_NODE == type) continue; return makeNodeHandle(current); // make handle. } } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { // Compute in ID space current=makeNodeIdentity(current); while (true) { current++; int etype = _exptype(current); // may call nextNode() if (NULL == etype) return NULL; if (etype != expandedTypeID) continue; return makeNodeHandle(current); // make handle. } } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class FollowingSiblingTraverser extends DTMAxisTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return getNextSibling(current); } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { while (DTM.NULL != (current = getNextSibling(current))) { if (getExpandedTypeID(current) == expandedTypeID) return current; } return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class NamespaceDeclsTraverser extends DTMAxisTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return (context == current) ? getFirstNamespaceNode(context, false) : getNextNamespaceNode(context, current, false); } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { current = (context == current) ? getFirstNamespaceNode(context, false) : getNextNamespaceNode(context, current, false); do { if (getExpandedTypeID(current) == expandedTypeID) return current; } while (DTM.NULL != (current = getNextNamespaceNode(context, current, false))); return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class NamespaceTraverser extends DTMAxisTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return (context == current) ? getFirstNamespaceNode(context, true) : getNextNamespaceNode(context, current, true); } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { current = (context == current) ? getFirstNamespaceNode(context, true) : getNextNamespaceNode(context, current, true); do { if (getExpandedTypeID(current) == expandedTypeID) return current; } while (DTM.NULL != (current = getNextNamespaceNode(context, current, true))); return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class ParentTraverser extends DTMAxisTraverser { /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * that the traversal starts from. * @return the first node in the traversal. */ public int first(int context) { return getParent(context); } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int current, int expandedTypeID) { // Compute in ID space current = makeNodeIdentity(current); while (NULL != (current = m_parent.elementAt(current))) { if (m_exptype.elementAt(current) == expandedTypeID) return makeNodeHandle(current); } return NULL; } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return NULL; } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class PrecedingTraverser extends DTMAxisTraverser { /** * Tell if the current identity is an ancestor of the context identity. * This is an expensive operation, made worse by the stateless traversal. * But the preceding axis is used fairly infrequently. * * @param contextIdent The context node of the axis traversal. * @param currentIdent The node in question. * @return true if the currentIdent node is an ancestor of contextIdent. */ protected boolean isAncestor(int contextIdent, int currentIdent) { // %REVIEW% See comments in IsAfterAxis; using the "successor" of // contextIdent is probably more efficient. for (contextIdent = m_parent.elementAt(contextIdent); DTM.NULL != contextIdent; contextIdent = m_parent.elementAt(contextIdent)) { if (contextIdent == currentIdent) return true; } return false; } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { // compute in ID space int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) - 1; current >= 0; current--) { short type = _type(current); if (ATTRIBUTE_NODE == type || NAMESPACE_NODE == type || isAncestor(subtreeRootIdent, current)) continue; return makeNodeHandle(current); // make handle. } return NULL; } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { // Compute in ID space int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) - 1; current >= 0; current--) { int exptype = m_exptype.elementAt(current); if (exptype != expandedTypeID || isAncestor(subtreeRootIdent, current)) continue; return makeNodeHandle(current); // make handle. } return NULL; } } /** * Implements traversal of the Ancestor and the Preceding axis, * in reverse document order. */ private class PrecedingAndAncestorTraverser extends DTMAxisTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { // Compute in ID space int subtreeRootIdent = makeNodeIdentity(context ); for (current = makeNodeIdentity(current) - 1; current >= 0; current--) { short type = _type(current); if (ATTRIBUTE_NODE == type || NAMESPACE_NODE == type) continue; return makeNodeHandle(current); // make handle. } return NULL; } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { // Compute in ID space int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) - 1; current >= 0; current--) { int exptype = m_exptype.elementAt(current); if (exptype != expandedTypeID) continue; return makeNodeHandle(current); // make handle. } return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class PrecedingSiblingTraverser extends DTMAxisTraverser { /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { return getPreviousSibling(current); } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { while (DTM.NULL != (current = getPreviousSibling(current))) { if (getExpandedTypeID(current) == expandedTypeID) return current; } return NULL; } } /** * Implements traversal of the Self axis. */ private class SelfTraverser extends DTMAxisTraverser { /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. To see if * the self node should be processed, use this function. * * @param context The context node of this traversal. * * @return the first node in the traversal. */ public int first(int context) { return context; } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. To see if * the self node should be processed, use this function. If the context * node does not match the expanded type ID, this function will return * false. * * @param context The context node of this traversal. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { return (getExpandedTypeID(context) == expandedTypeID) ? context : NULL; } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return Always return NULL for this axis. */ public int next(int context, int current) { return NULL; } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { return NULL; } } /** * Implements traversal of the Ancestor access, in reverse document order. */ private class AllFromRootTraverser extends AllFromNodeTraverser { /** * Return the root. * * @param context The context node of this traversal. * * @return the first node in the traversal. */ public int first(int context) { return getDocumentRoot(context); } /** * Return the root if it matches the expanded type ID. * * @param context The context node of this traversal. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { return (getExpandedTypeID(getDocumentRoot(context)) == expandedTypeID) ? context : next(context, context, expandedTypeID); } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current) { // Compute in ID space int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) + 1; ; current++) { // Kluge test: Just make sure +1 yielded a real node int type = _type(current); // may call nextNode() if (type == NULL) return NULL; return makeNodeHandle(current); // make handle. } } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { // Compute in ID space int subtreeRootIdent = makeNodeIdentity(context); for (current = makeNodeIdentity(current) + 1; ; current++) { int exptype = _exptype(current); // may call nextNode() if (exptype == NULL) return NULL; if (exptype != expandedTypeID) continue; return makeNodeHandle(current); // make handle. } } } /** * Implements traversal of the Self axis. */ private class RootTraverser extends AllFromRootTraverser { /** * Return the root if it matches the expanded type ID, * else return null (nothing found) * * @param context The context node of this traversal. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { int root=getDocumentRoot(context); return (getExpandedTypeID(root) == expandedTypeID) ? root : NULL; } /** * Traverse to the next node after the current node. * * @param context The context node of this iteration. * @param current The current node of the iteration. * * @return Always return NULL for this axis. */ public int next(int context, int current) { return NULL; } /** * Traverse to the next node after the current node that is matched * by the expanded type ID. * * @param context The context node of this iteration. * @param current The current node of the iteration. * @param expandedTypeID The expanded type ID that must match. * * @return the next node in the iteration, or DTM.NULL. */ public int next(int context, int current, int expandedTypeID) { return NULL; } } /** * A non-xpath axis, returns all nodes that aren't namespaces or attributes, * from and including the root. */ private class DescendantOrSelfFromRootTraverser extends DescendantTraverser { /** * Get the first potential identity that can be returned, which is the axis * root context in this case. * * @param identity The node identity of the root context of the traversal. * * @return The identity argument. */ protected int getFirstPotential(int identity) { return identity; } /** * Get the first potential identity that can be returned. * @param handle handle to the root context. * @return identity of the root of the subtree. */ protected int getSubtreeRoot(int handle) { // %REVIEW% Shouldn't this always be 0? return makeNodeIdentity(getDocument()); } /** * Return the root. * * @param context The context node of this traversal. * * @return the first node in the traversal. */ public int first(int context) { return getDocumentRoot(context); } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { if (isIndexed(expandedTypeID)) { int identity = 0; int firstPotential = getFirstPotential(identity); return makeNodeHandle(getNextIndexed(identity, firstPotential, expandedTypeID)); } int root = first(context); return next(root, root, expandedTypeID); } } /** * A non-xpath axis, returns all nodes that aren't namespaces or attributes, * from but not including the root. */ private class DescendantFromRootTraverser extends DescendantTraverser { /** * Get the first potential identity that can be returned, which is the axis * root context in this case. * * @param identity The node identity of the root context of the traversal. * * @return The identity argument. */ protected int getFirstPotential(int identity) { return _firstch(0); } /** * Get the first potential identity that can be returned. * @param handle handle to the root context. * @return identity of the root of the subtree. */ protected int getSubtreeRoot(int handle) { return 0; } /** * Return the root. * * @param context The context node of this traversal. * * @return the first node in the traversal. */ public int first(int context) { return makeNodeHandle(_firstch(0)); } /** * By the nature of the stateless traversal, the context node can not be * returned or the iteration will go into an infinate loop. So to traverse * an axis, the first function must be used to get the first node. * *

This method needs to be overloaded only by those axis that process * the self node. <\p> * * @param context The context node of this traversal. This is the point * of origin for the traversal -- its "root node" or starting point. * @param expandedTypeID The expanded type ID that must match. * * @return the first node in the traversal. */ public int first(int context, int expandedTypeID) { if (isIndexed(expandedTypeID)) { int identity = 0; int firstPotential = getFirstPotential(identity); return makeNodeHandle(getNextIndexed(identity, firstPotential, expandedTypeID)); } int root = getDocumentRoot(context); return next(root, root, expandedTypeID); } } }





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