- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * Licensed 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: WalkingIteratorSorted.java,v 1.11 2004/02/17 04:32:08 minchau Exp $
- */
- package com.sun.org.apache.xpath.internal.axes;
-
- import com.sun.org.apache.xml.internal.dtm.Axis;
- import com.sun.org.apache.xml.internal.utils.PrefixResolver;
- import com.sun.org.apache.xpath.internal.compiler.Compiler;
-
- /**
- * This class iterates over set of nodes that needs to be sorted.
- * @xsl.usage internal
- */
- 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));
- }
-
- }
-
- }