| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| package org.apache.xpath.axes; |
| |
| import org.apache.xml.dtm.Axis; |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.dtm.DTMAxisTraverser; |
| import org.apache.xml.dtm.DTMIterator; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.compiler.Compiler; |
| import org.apache.xpath.compiler.OpMap; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.patterns.NodeTest; |
| import org.apache.xpath.patterns.StepPattern; |
| |
| /** |
| * This class treats a |
| * <a href="http://www.w3.org/TR/xpath#location-paths">LocationPath</a> as a |
| * filtered iteration over the tree, evaluating each node in a super axis |
| * traversal against the LocationPath interpreted as a match pattern. This |
| * class is useful to find nodes in document order that are complex paths |
| * whose steps probably criss-cross each other. |
| */ |
| public class MatchPatternIterator extends LocPathIterator |
| { |
| static final long serialVersionUID = -5201153767396296474L; |
| |
| /** This is the select pattern, translated into a match pattern. */ |
| protected StepPattern m_pattern; |
| |
| /** The traversal axis from where the nodes will be filtered. */ |
| protected int m_superAxis = -1; |
| |
| /** The DTM inner traversal class, that corresponds to the super axis. */ |
| protected DTMAxisTraverser m_traverser; |
| |
| /** DEBUG flag for diagnostic dumps. */ |
| private static final boolean DEBUG = false; |
| |
| // protected int m_nsElemBase = DTM.NULL; |
| |
| /** |
| * Create a LocPathIterator object, 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 analysis Analysis bits that give general information about the |
| * LocationPath. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| MatchPatternIterator(Compiler compiler, int opPos, int analysis) |
| throws javax.xml.transform.TransformerException |
| { |
| |
| super(compiler, opPos, analysis, false); |
| |
| int firstStepPos = OpMap.getFirstChildPos(opPos); |
| |
| m_pattern = WalkerFactory.loadSteps(this, compiler, firstStepPos, 0); |
| |
| boolean fromRoot = false; |
| boolean walkBack = false; |
| boolean walkDescendants = false; |
| boolean walkAttributes = false; |
| |
| if (0 != (analysis & (WalkerFactory.BIT_ROOT | |
| WalkerFactory.BIT_ANY_DESCENDANT_FROM_ROOT))) |
| fromRoot = true; |
| |
| if (0 != (analysis |
| & (WalkerFactory.BIT_ANCESTOR |
| | WalkerFactory.BIT_ANCESTOR_OR_SELF |
| | WalkerFactory.BIT_PRECEDING |
| | WalkerFactory.BIT_PRECEDING_SIBLING |
| | WalkerFactory.BIT_FOLLOWING |
| | WalkerFactory.BIT_FOLLOWING_SIBLING |
| | WalkerFactory.BIT_PARENT | WalkerFactory.BIT_FILTER))) |
| walkBack = true; |
| |
| if (0 != (analysis |
| & (WalkerFactory.BIT_DESCENDANT_OR_SELF |
| | WalkerFactory.BIT_DESCENDANT |
| | WalkerFactory.BIT_CHILD))) |
| walkDescendants = true; |
| |
| if (0 != (analysis |
| & (WalkerFactory.BIT_ATTRIBUTE | WalkerFactory.BIT_NAMESPACE))) |
| walkAttributes = true; |
| |
| if(false || DEBUG) |
| { |
| System.out.print("analysis: "+Integer.toBinaryString(analysis)); |
| System.out.println(", "+WalkerFactory.getAnalysisString(analysis)); |
| } |
| |
| if(fromRoot || walkBack) |
| { |
| if(walkAttributes) |
| { |
| m_superAxis = Axis.ALL; |
| } |
| else |
| { |
| m_superAxis = Axis.DESCENDANTSFROMROOT; |
| } |
| } |
| else if(walkDescendants) |
| { |
| if(walkAttributes) |
| { |
| m_superAxis = Axis.ALLFROMNODE; |
| } |
| else |
| { |
| m_superAxis = Axis.DESCENDANTORSELF; |
| } |
| } |
| else |
| { |
| m_superAxis = Axis.ALL; |
| } |
| if(false || DEBUG) |
| { |
| System.out.println("axis: "+Axis.getNames(m_superAxis)); |
| } |
| |
| } |
| |
| |
| /** |
| * Initialize the context values for this expression |
| * after it is cloned. |
| * |
| * @param context The XPath runtime context for this |
| * transformation. |
| */ |
| public void setRoot(int context, Object environment) |
| { |
| super.setRoot(context, environment); |
| m_traverser = m_cdtm.getAxisTraverser(m_superAxis); |
| } |
| |
| /** |
| * Detaches the iterator from the set which it iterated over, releasing |
| * any computational resources and placing the iterator in the INVALID |
| * state. After<code>detach</code> has been invoked, calls to |
| * <code>nextNode</code> or<code>previousNode</code> will raise the |
| * exception INVALID_STATE_ERR. |
| */ |
| public void detach() |
| { |
| if(m_allowDetach) |
| { |
| m_traverser = null; |
| |
| // Always call the superclass detach last! |
| super.detach(); |
| } |
| } |
| |
| /** |
| * Get the next node via getNextXXX. Bottlenecked for derived class override. |
| * @return The next node on the axis, or DTM.NULL. |
| */ |
| protected int getNextNode() |
| { |
| m_lastFetched = (DTM.NULL == m_lastFetched) |
| ? m_traverser.first(m_context) |
| : m_traverser.next(m_context, m_lastFetched); |
| return m_lastFetched; |
| } |
| |
| /** |
| * 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. |
| */ |
| public int nextNode() |
| { |
| if(m_foundLast) |
| return DTM.NULL; |
| |
| int next; |
| |
| org.apache.xpath.VariableStack vars; |
| int savedStart; |
| if (-1 != m_stackFrame) |
| { |
| vars = m_execContext.getVarStack(); |
| |
| // These three statements need to be combined into one operation. |
| savedStart = vars.getStackFrame(); |
| |
| vars.setStackFrame(m_stackFrame); |
| } |
| else |
| { |
| // Yuck. Just to shut up the compiler! |
| vars = null; |
| savedStart = 0; |
| } |
| |
| try |
| { |
| if(DEBUG) |
| System.out.println("m_pattern"+m_pattern.toString()); |
| |
| do |
| { |
| next = getNextNode(); |
| |
| if (DTM.NULL != next) |
| { |
| if(DTMIterator.FILTER_ACCEPT == acceptNode(next, m_execContext)) |
| break; |
| else |
| continue; |
| } |
| else |
| break; |
| } |
| while (next != DTM.NULL); |
| |
| if (DTM.NULL != next) |
| { |
| if(DEBUG) |
| { |
| System.out.println("next: "+next); |
| System.out.println("name: "+m_cdtm.getNodeName(next)); |
| } |
| incrementCurrentPos(); |
| |
| return next; |
| } |
| else |
| { |
| m_foundLast = true; |
| |
| return DTM.NULL; |
| } |
| } |
| finally |
| { |
| if (-1 != m_stackFrame) |
| { |
| // These two statements need to be combined into one operation. |
| vars.setStackFrame(savedStart); |
| } |
| } |
| |
| } |
| |
| /** |
| * Test whether a specified node is visible in the logical view of a |
| * TreeWalker or NodeIterator. This function will be called by the |
| * implementation of TreeWalker and NodeIterator; it is not intended to |
| * be called directly from user code. |
| * @param n The node to check to see if it passes the filter or not. |
| * @return a constant to determine whether the node is accepted, |
| * rejected, or skipped, as defined above . |
| */ |
| public short acceptNode(int n, XPathContext xctxt) |
| { |
| |
| try |
| { |
| xctxt.pushCurrentNode(n); |
| xctxt.pushIteratorRoot(m_context); |
| if(DEBUG) |
| { |
| System.out.println("traverser: "+m_traverser); |
| System.out.print("node: "+n); |
| System.out.println(", "+m_cdtm.getNodeName(n)); |
| // if(m_cdtm.getNodeName(n).equals("near-east")) |
| System.out.println("pattern: "+m_pattern.toString()); |
| m_pattern.debugWhatToShow(m_pattern.getWhatToShow()); |
| } |
| |
| XObject score = m_pattern.execute(xctxt); |
| |
| if(DEBUG) |
| { |
| // System.out.println("analysis: "+Integer.toBinaryString(m_analysis)); |
| System.out.println("score: "+score); |
| System.out.println("skip: "+(score == NodeTest.SCORE_NONE)); |
| } |
| |
| // System.out.println("\n::acceptNode - score: "+score.num()+"::"); |
| return (score == NodeTest.SCORE_NONE) ? DTMIterator.FILTER_SKIP |
| : DTMIterator.FILTER_ACCEPT; |
| } |
| catch (javax.xml.transform.TransformerException se) |
| { |
| |
| // TODO: Fix this. |
| throw new RuntimeException(se.getMessage()); |
| } |
| finally |
| { |
| xctxt.popCurrentNode(); |
| xctxt.popIteratorRoot(); |
| } |
| |
| } |
| |
| } |