dtmdefaultbase.java

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        case DTM.NULL :
          typestring = "null";
          break;
        case DTM.PROCESSING_INSTRUCTION_NODE :
          typestring = "PI";
          break;
        case DTM.TEXT_NODE :
          typestring = "TEXT";
          break;
        default :
          typestring = "Unknown!";
          break;
        }

      StringBuffer sb=new StringBuffer();
	  sb.append("["+nodeHandle+": "+typestring+
				"(0x"+Integer.toHexString(getExpandedTypeID(nodeHandle))+") "+
				getNodeNameX(nodeHandle)+" {"+getNamespaceURI(nodeHandle)+"}"+
				"=\""+ getNodeValue(nodeHandle)+"\"]");
	  return sb.toString();
  }

  // ========= DTM Implementation Control Functions. ==============

  /**
   * Set an implementation dependent feature.
   * <p>
   * %REVIEW% Do we really expect to set features on DTMs?
   *
   * @param featureId A feature URL.
   * @param state true if this feature should be on, false otherwise.
   */
  public void setFeature(String featureId, boolean state){}

  // ========= Document Navigation Functions =========

  /**
   * Given a node handle, test if it has child nodes.
   * <p> %REVIEW% This is obviously useful at the DOM layer, where it
   * would permit testing this without having to create a proxy
   * node. It's less useful in the DTM API, where
   * (dtm.getFirstChild(nodeHandle)!=DTM.NULL) is just as fast and
   * almost as self-evident. But it's a convenience, and eases porting
   * of DOM code to DTM.  </p>
   *
   * @param nodeHandle int Handle of the node.
   * @return int true if the given node has child nodes.
   */
  public boolean hasChildNodes(int nodeHandle)
  {

    int identity = makeNodeIdentity(nodeHandle);
    int firstChild = _firstch(identity);

    return firstChild != DTM.NULL;
  }
	
  /** Given a node identity, return a node handle. If extended addressing
   * has been used (multiple DTM IDs), we need to map the high bits of the
   * identity into the proper DTM ID.
   * 
   * This has been made FINAL to facilitate inlining, since we do not expect
   * any subclass of DTMDefaultBase to ever change the algorithm. (I don't
   * really like doing so, and would love to have an excuse not to...)
   * 
   * %REVIEW% Is it worth trying to specialcase small documents?
   * %REVIEW% Should this be exposed at the package/public layers?
   * 
   * @param nodeIdentity Internal offset to this node's records.
   * @return NodeHandle (external representation of node)
   * */
  final public int makeNodeHandle(int nodeIdentity)
  {
    if(NULL==nodeIdentity) return NULL;
		
    if(JJK_DEBUG && nodeIdentity>DTMManager.IDENT_NODE_DEFAULT)
      System.err.println("GONK! (only useful in limited situations)");

    return m_dtmIdent.elementAt(nodeIdentity >>> DTMManager.IDENT_DTM_NODE_BITS)
      + (nodeIdentity & DTMManager.IDENT_NODE_DEFAULT) ;											
  }
	
  /** Given a node handle, return a node identity. If extended addressing
   * has been used (multiple DTM IDs), we need to map the high bits of the
   * identity into the proper DTM ID and thence find the proper offset
   * to add to the low bits of the identity
   * 
   * This has been made FINAL to facilitate inlining, since we do not expect
   * any subclass of DTMDefaultBase to ever change the algorithm. (I don't
   * really like doing so, and would love to have an excuse not to...)
   * 
   * %OPT% Performance is critical for this operation.
   *
   * %REVIEW% Should this be exposed at the package/public layers?
   * 
   * @param nodeHandle (external representation of node)
   * @return nodeIdentity Internal offset to this node's records.
   * */
  final public int makeNodeIdentity(int nodeHandle)
  {
    if(NULL==nodeHandle) return NULL;

    if(m_mgrDefault!=null)
    {
      // Optimization: use the DTMManagerDefault's fast DTMID-to-offsets
      // table.  I'm not wild about this solution but this operation
      // needs need extreme speed.

      int whichDTMindex=nodeHandle>>>DTMManager.IDENT_DTM_NODE_BITS;

      // %REVIEW% Wish I didn't have to perform the pre-test, but
      // someone is apparently asking DTMs whether they contain nodes
      // which really don't belong to them. That's probably a bug
      // which should be fixed, but until it is:
      if(m_mgrDefault.m_dtms[whichDTMindex]!=this)
	return NULL;
      else
	return
	  m_mgrDefault.m_dtm_offsets[whichDTMindex]
	  | (nodeHandle & DTMManager.IDENT_NODE_DEFAULT);
    }
	  
    int whichDTMid=m_dtmIdent.indexOf(nodeHandle & DTMManager.IDENT_DTM_DEFAULT);
    return (whichDTMid==NULL) 
      ? NULL
      : (whichDTMid << DTMManager.IDENT_DTM_NODE_BITS)
      + (nodeHandle & DTMManager.IDENT_NODE_DEFAULT);
  }


  /**
   * Given a node handle, get the handle of the node's first child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of first child, or DTM.NULL to indicate none exists.
   */
  public int getFirstChild(int nodeHandle)
  {

    int identity = makeNodeIdentity(nodeHandle);
    int firstChild = _firstch(identity);

    return makeNodeHandle(firstChild);
  }
  
  /**
   * Given a node handle, get the handle of the node's first child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of first child, or DTM.NULL to indicate none exists.
   */
  public int getTypedFirstChild(int nodeHandle, int nodeType)
  {

    int firstChild, eType;
    if (nodeType < DTM.NTYPES) {
      for (firstChild = _firstch(makeNodeIdentity(nodeHandle));
           firstChild != DTM.NULL;
           firstChild = _nextsib(firstChild)) {
        eType = _exptype(firstChild);
        if (eType == nodeType
               || (eType >= DTM.NTYPES
                      && m_expandedNameTable.getType(eType) == nodeType)) {
          return makeNodeHandle(firstChild);
        }
      }
    } else {
      for (firstChild = _firstch(makeNodeIdentity(nodeHandle));
           firstChild != DTM.NULL;
           firstChild = _nextsib(firstChild)) {
        if (_exptype(firstChild) == nodeType) {
          return makeNodeHandle(firstChild);
        }
      }
    }
    return DTM.NULL;
  }

  /**
   * Given a node handle, advance to its last child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of last child,
   * or DTM.NULL to indicate none exists.
   */
  public int getLastChild(int nodeHandle)
  {

    int identity = makeNodeIdentity(nodeHandle);
    int child = _firstch(identity);
    int lastChild = DTM.NULL;

    while (child != DTM.NULL)
    {
      lastChild = child;
      child = _nextsib(child);
    }

    return makeNodeHandle(lastChild);
  }

  /**
   * Retrieves an attribute node by by qualified name and namespace URI.
   *
   * @param nodeHandle int Handle of the node upon which to look up this attribute..
   * @param namespaceURI The namespace URI of the attribute to
   *   retrieve, or null.
   * @param name The local name of the attribute to
   *   retrieve.
   * @return The attribute node handle with the specified name (
   *   <code>nodeName</code>) or <code>DTM.NULL</code> if there is no such
   *   attribute.
   */
  public abstract int getAttributeNode(int nodeHandle, String namespaceURI,
                                       String name);

  /**
   * Given a node handle, get the index of the node's first attribute.
   *
   * @param nodeHandle int Handle of the node.
   * @return Handle of first attribute, or DTM.NULL to indicate none exists.
   */
  public int getFirstAttribute(int nodeHandle)
  {
    int nodeID = makeNodeIdentity(nodeHandle);

    return makeNodeHandle(getFirstAttributeIdentity(nodeID));
  }

  /**
   * Given a node identity, get the index of the node's first attribute.
   *
   * @param identity int identity of the node.
   * @return Identity of first attribute, or DTM.NULL to indicate none exists.
   */
  protected int getFirstAttributeIdentity(int identity) {
    int type = _type(identity);

    if (DTM.ELEMENT_NODE == type)
    {
      // Assume that attributes and namespaces immediately follow the element.
      while (DTM.NULL != (identity = getNextNodeIdentity(identity)))
      {

        // Assume this can not be null.
        type = _type(identity);

        if (type == DTM.ATTRIBUTE_NODE)
        {
          return identity;
        }
        else if (DTM.NAMESPACE_NODE != type)
        {
          break;
        }
      }
    }

    return DTM.NULL;
  }

  /**
   * Given a node handle and an expanded type ID, get the index of the node's
   * attribute of that type, if any.
   *
   * @param nodeHandle int Handle of the node.
   * @param attType int expanded type ID of the required attribute.
   * @return Handle of attribute of the required type, or DTM.NULL to indicate
   * none exists.
   */
  protected int getTypedAttribute(int nodeHandle, int attType) {
    int type = getNodeType(nodeHandle);
    if (DTM.ELEMENT_NODE == type) {
      int identity = makeNodeIdentity(nodeHandle);

      while (DTM.NULL != (identity = getNextNodeIdentity(identity)))
      {
        type = _type(identity);

        if (type == DTM.ATTRIBUTE_NODE)
        {
          if (_exptype(identity) == attType) return makeNodeHandle(identity);
        }
        else if (DTM.NAMESPACE_NODE != type)
        {
          break;
        }
      }
    }

    return DTM.NULL;
  }

  /**
   * Given a node handle, advance to its next sibling.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of next sibling,
   * or DTM.NULL to indicate none exists.
   */
  public int getNextSibling(int nodeHandle)
  {
  	if (nodeHandle == DTM.NULL)
  	return DTM.NULL;
    return makeNodeHandle(_nextsib(makeNodeIdentity(nodeHandle)));
  }
  
  /**
   * Given a node handle, advance to its next sibling.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of next sibling,
   * or DTM.NULL to indicate none exists.
   */
  public int getTypedNextSibling(int nodeHandle, int nodeType)
  {
  	if (nodeHandle == DTM.NULL)
  	return DTM.NULL;
  	int node = makeNodeIdentity(nodeHandle);
  	int eType;
  	while ((node = _nextsib(node)) != DTM.NULL && 
  	((eType = _exptype(node)) != nodeType && 
  	m_expandedNameTable.getType(eType)!= nodeType)); 
  	//_type(node) != nodeType));
        
    return (node == DTM.NULL ? DTM.NULL : makeNodeHandle(node));
  }

  /**
   * Given a node handle, find its preceeding sibling.
   * WARNING: DTM is asymmetric; this operation is resolved by search, and is
   * relatively expensive.
   *
   * @param nodeHandle the id of the node.
   * @return int Node-number of the previous sib,
   * or DTM.NULL to indicate none exists.
   */
  public int getPreviousSibling(int nodeHandle)
  {
    if (nodeHandle == DTM.NULL)
      return DTM.NULL;
    
    if (m_prevsib != null)
      return makeNodeHandle(_prevsib(makeNodeIdentity(nodeHandle)));
    else
    {
      // If the previous sibling array is not built, we get at
      // the previous sibling using the parent, firstch and 
      // nextsib arrays. 
      int nodeID = makeNodeIdentity(nodeHandle);
      int parent = _parent(nodeID);
      int node = _firstch(parent);
      int result = DTM.NULL;
      while (node != nodeID)
      {
        result = node;
        node = _nextsib(node);
      }
      return makeNodeHandle(result);
    }
  }

  /**
   * Given a node handle, advance to the next attribute.
   * If an attr, we advance to
   * the next attr on the same node.  If not an attribute, we return NULL.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of the resolved attr,
   * or DTM.NULL to indicate none exists.
   */
  public int getNextAttribute(int nodeHandle) {
    int nodeID = makeNodeIdentity(nodeHandle);

    if (_type(nodeID) == DTM.ATTRIBUTE_NODE) {
      return makeNodeHandle(getNextAttributeIdentity(nodeID));
    }

    return DTM.NULL;
  }

  /**
   * Given a node identity for an attribute, advance to the next attribute.
   *
   * @param identity int identity of the attribute node.  This
   * <strong>must</strong> be an attribute node.
   *
   * @return int DTM node-identity of the resolved attr,
   * or DTM.NULL to indicate none exists.
   *
   */
  protected int getNextAttributeIdentity(int identity) {
    // Assume that attributes and namespace nodes immediately follow the element
    while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {
      int type = _type(identity);

      if (type == DTM.ATTRIBUTE_NODE) {
        return identity;
      } else if (type != DTM.NAMESPACE_NODE) {
        break;
      }
    }

    return DTM.NULL;
  }