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Posted to commits@xalan.apache.org by sb...@locus.apache.org on 2000/12/14 19:38:39 UTC
cvs commit: xml-xalan/java/src/org/apache/xpath/axes AttributeIterator.java
sboag 00/12/14 10:38:38
Added: java/src/org/apache/xpath/axes AttributeIterator.java
Log:
Optimized attribute iterator.
Revision Changes Path
1.1 xml-xalan/java/src/org/apache/xpath/axes/AttributeIterator.java
Index: AttributeIterator.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xpath.axes;
import javax.xml.transform.TransformerException;
import org.apache.xpath.compiler.Compiler;
import org.apache.xpath.patterns.NodeTest;
import org.apache.xpath.objects.XObject;
import org.w3c.dom.traversal.NodeIterator;
import org.w3c.dom.Node;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.DOMException;
import org.w3c.dom.traversal.NodeFilter;
/**
* <meta name="usage" content="advanced"/>
* This class implements an optimized iterator for
* attribute axes patterns.
* @see org.apache.xpath.axes.WalkerFactory#newLocPathIterator.
*/
public class AttributeIterator extends LocPathIterator
{
/**
* Create a AttributeIterator object.
*
* @param compiler A reference to the Compiler that contains the op map.
* @param opPos The position within the op map, which contains the
* location path expression for this itterator.
*
* @throws javax.xml.transform.TransformerException
*/
public AttributeIterator(Compiler compiler, int opPos)
throws javax.xml.transform.TransformerException
{
super(compiler, opPos, false);
m_nodeTest = new NodeTest();
int firstStepPos = compiler.getFirstChildPos(opPos);
int whatToShow = compiler.getWhatToShow(firstStepPos);
if ((0 == (whatToShow
& (NodeFilter.SHOW_ATTRIBUTE | NodeFilter.SHOW_ELEMENT
| NodeFilter.SHOW_PROCESSING_INSTRUCTION))) || (whatToShow == NodeFilter.SHOW_ALL))
m_nodeTest.initNodeTest(whatToShow);
else
{
m_nodeTest.initNodeTest(whatToShow, compiler.getStepNS(firstStepPos),
compiler.getStepLocalName(firstStepPos));
}
}
/**
* Get a cloned LocPathIterator that holds the same
* position as this iterator.
*
* @return A clone of this iterator that holds the same node position.
*
* @throws CloneNotSupportedException
*/
public Object clone() throws CloneNotSupportedException
{
LocPathIterator clone = (LocPathIterator) super.clone();
return clone;
}
/**
* Get a cloned Iterator that is reset to the beginning
* of the query.
*
* @return A cloned NodeIterator set of the start of the query.
*
* @throws CloneNotSupportedException
*/
public NodeIterator cloneWithReset() throws CloneNotSupportedException
{
AttributeIterator clone = (AttributeIterator) super.cloneWithReset();
clone.m_attrListPos = 0;
return clone;
}
/**
* Initialize the attribute list.
*/
private void initAttrList()
{
if (m_context.getNodeType() == Node.ELEMENT_NODE)
{
m_attrListPos = 0;
m_attributeList = m_context.getAttributes();
if (null != m_attributeList)
{
m_nAttrs = m_attributeList.getLength();
}
else
m_nAttrs = 0;
if (0 == m_nAttrs)
{
m_foundLast = true;
}
}
}
/**
* Returns the next node in the set and advances the position of the
* iterator in the set. After a NodeIterator is created, the first call
* to nextNode() returns the first node in the set.
*
* @return The next <code>Node</code> in the set being iterated over, or
* <code>null</code> if there are no more members in that set.
*
* @exception DOMException
* INVALID_STATE_ERR: Raised if this method is called after the
* <code>detach</code> method was invoked.
*/
public Node nextNode() throws DOMException
{
// If the cache is on, and the node has already been found, then
// just return from the list.
if ((null != m_cachedNodes)
&& (m_cachedNodes.getCurrentPos() < m_cachedNodes.size()))
{
Node next = m_cachedNodes.nextNode();
this.setCurrentPos(m_cachedNodes.getCurrentPos());
return next;
}
if (m_foundLast)
return null;
if (null == m_attributeList)
{
initAttrList();
}
Node next;
do
{
m_lastFetched = next =
(null == m_attributeList || m_attrListPos >= m_nAttrs)
? null : m_attributeList.item(m_attrListPos++);
if (null != next)
{
try
{
XObject score = m_nodeTest.execute(m_execContext, next);
if (NodeTest.SCORE_NONE == score)
continue;
else
break;
}
catch (TransformerException te)
{
throw new org.apache.xml.utils.WrappedRuntimeException(te);
}
}
else
break;
}
while (next != null);
if (null != next)
{
if (null != m_cachedNodes)
m_cachedNodes.addElement(m_lastFetched);
m_next++;
return next;
}
else
{
m_foundLast = true;
return null;
}
}
/** The NodeTest for this iterator. */
private NodeTest m_nodeTest;
/** The attribute list for the given context. */
private NamedNodeMap m_attributeList;
/** The position within the attribute list. */
private int m_attrListPos = 0;
/** The number of attributes within the list. */
private int m_nAttrs = 0;
}