| /* |
| * 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 org.apache.xpath.XPathContext; |
| import org.apache.xml.utils.PrefixResolver; |
| import org.apache.xpath.compiler.Compiler; |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.dtm.DTMIterator; |
| import org.apache.xml.dtm.Axis; |
| |
| /** |
| * <meta name="usage" content="internal"/> |
| * This class iterates over set of nodes that needs to be sorted. |
| */ |
| public class WalkingIteratorSorted extends WalkingIterator |
| { |
| |
| // /** True if the nodes will be found in document order */ |
| // protected boolean m_inNaturalOrder = false; |
| |
| /** True if the nodes will be found in document order, and this can |
| * be determined statically. */ |
| protected boolean m_inNaturalOrderStatic = false; |
| |
| /** |
| * Create a WalkingIteratorSorted object. |
| * |
| * @param nscontext The namespace context for this iterator, |
| * should be OK if null. |
| */ |
| public WalkingIteratorSorted(PrefixResolver nscontext) |
| { |
| super(nscontext); |
| } |
| |
| /** |
| * Create a WalkingIterator iterator, including creation |
| * of step walkers from the opcode list, and call back |
| * into the Compiler to create predicate expressions. |
| * |
| * @param compiler The Compiler which is creating |
| * this expression. |
| * @param opPos The position of this iterator in the |
| * opcode list from the compiler. |
| * @param shouldLoadWalkers True if walkers should be |
| * loaded, or false if this is a derived iterator and |
| * it doesn't wish to load child walkers. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| WalkingIteratorSorted( |
| Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers) |
| throws javax.xml.transform.TransformerException |
| { |
| super(compiler, opPos, analysis, shouldLoadWalkers); |
| } |
| |
| /** |
| * Returns true if all the nodes in the iteration well be returned in document |
| * order. |
| * |
| * @return true as a default. |
| */ |
| public boolean isDocOrdered() |
| { |
| return m_inNaturalOrderStatic; |
| } |
| |
| |
| /** |
| * Tell if the nodeset can be walked in doc order, via static analysis. |
| * |
| * |
| * @return true if the nodeset can be walked in doc order, without sorting. |
| */ |
| boolean canBeWalkedInNaturalDocOrderStatic() |
| { |
| |
| if (null != m_firstWalker) |
| { |
| AxesWalker walker = m_firstWalker; |
| int prevAxis = -1; |
| boolean prevIsSimpleDownAxis = true; |
| |
| for(int i = 0; null != walker; i++) |
| { |
| int axis = walker.getAxis(); |
| |
| if(walker.isDocOrdered()) |
| { |
| boolean isSimpleDownAxis = ((axis == Axis.CHILD) |
| || (axis == Axis.SELF) |
| || (axis == Axis.ROOT)); |
| // Catching the filtered list here is only OK because |
| // FilterExprWalker#isDocOrdered() did the right thing. |
| if(isSimpleDownAxis || (axis == -1)) |
| walker = walker.getNextWalker(); |
| else |
| { |
| boolean isLastWalker = (null == walker.getNextWalker()); |
| if(isLastWalker) |
| { |
| if(walker.isDocOrdered() && (axis == Axis.DESCENDANT || |
| axis == Axis.DESCENDANTORSELF || axis == Axis.DESCENDANTSFROMROOT |
| || axis == Axis.DESCENDANTSORSELFFROMROOT) || (axis == Axis.ATTRIBUTE)) |
| return true; |
| } |
| return false; |
| } |
| } |
| else |
| return false; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| |
| // /** |
| // * NEEDSDOC Method canBeWalkedInNaturalDocOrder |
| // * |
| // * |
| // * NEEDSDOC (canBeWalkedInNaturalDocOrder) @return |
| // */ |
| // boolean canBeWalkedInNaturalDocOrder() |
| // { |
| // |
| // if (null != m_firstWalker) |
| // { |
| // AxesWalker walker = m_firstWalker; |
| // int prevAxis = -1; |
| // boolean prevIsSimpleDownAxis = true; |
| // |
| // for(int i = 0; null != walker; i++) |
| // { |
| // int axis = walker.getAxis(); |
| // |
| // if(walker.isDocOrdered()) |
| // { |
| // boolean isSimpleDownAxis = ((axis == Axis.CHILD) |
| // || (axis == Axis.SELF) |
| // || (axis == Axis.ROOT)); |
| // // Catching the filtered list here is only OK because |
| // // FilterExprWalker#isDocOrdered() did the right thing. |
| // if(isSimpleDownAxis || (axis == -1)) |
| // walker = walker.getNextWalker(); |
| // else |
| // { |
| // boolean isLastWalker = (null == walker.getNextWalker()); |
| // if(isLastWalker) |
| // { |
| // if(walker.isDocOrdered() && (axis == Axis.DESCENDANT || |
| // axis == Axis.DESCENDANTORSELF || axis == Axis.DESCENDANTSFROMROOT |
| // || axis == Axis.DESCENDANTSORSELFFROMROOT) || (axis == Axis.ATTRIBUTE)) |
| // return true; |
| // } |
| // return false; |
| // } |
| // } |
| // else |
| // return false; |
| // } |
| // return true; |
| // } |
| // return false; |
| // } |
| |
| /** |
| * This function is used to perform some extra analysis of the iterator. |
| * |
| * @param vars List of QNames that correspond to variables. This list |
| * should be searched backwards for the first qualified name that |
| * corresponds to the variable reference qname. The position of the |
| * QName in the vector from the start of the vector will be its position |
| * in the stack frame (but variables above the globalsTop value will need |
| * to be offset to the current stack frame). |
| */ |
| public void fixupVariables(java.util.Vector vars, int globalsSize) |
| { |
| super.fixupVariables(vars, globalsSize); |
| |
| int analysis = getAnalysisBits(); |
| if(WalkerFactory.isNaturalDocOrder(analysis)) |
| { |
| m_inNaturalOrderStatic = true; |
| } |
| else |
| { |
| m_inNaturalOrderStatic = false; |
| // System.out.println("Setting natural doc order to false: "+ |
| // WalkerFactory.getAnalysisString(analysis)); |
| } |
| |
| } |
| |
| } |
