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 [EMAIL PROTECTED] * * 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; }
