Java example source code file (StepPattern.java)
The StepPattern.java Java example source code
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* DO NOT REMOVE OR ALTER!
*/
/*
* 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: StepPattern.java,v 1.2.4.2 2005/09/15 00:21:16 jeffsuttor Exp $
*/
package com.sun.org.apache.xpath.internal.patterns;
import com.sun.org.apache.xml.internal.dtm.Axis;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMAxisTraverser;
import com.sun.org.apache.xml.internal.dtm.DTMFilter;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.XPathVisitor;
import com.sun.org.apache.xpath.internal.axes.SubContextList;
import com.sun.org.apache.xpath.internal.compiler.PsuedoNames;
import com.sun.org.apache.xpath.internal.objects.XObject;
/**
* This class represents a single pattern match step.
* @xsl.usage advanced
*/
public class StepPattern extends NodeTest implements SubContextList, ExpressionOwner
{
static final long serialVersionUID = 9071668960168152644L;
/** The axis for this test. */
protected int m_axis;
/**
* Construct a StepPattern that tests for namespaces and node names.
*
*
* @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
* @param namespace The namespace to be tested.
* @param name The local name to be tested.
* @param axis The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
* @param axisForPredicate No longer used.
*/
public StepPattern(int whatToShow, String namespace, String name, int axis,
int axisForPredicate)
{
super(whatToShow, namespace, name);
m_axis = axis;
}
/**
* Construct a StepPattern that doesn't test for node names.
*
*
* @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
* @param axis The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
* @param axisForPredicate No longer used.
*/
public StepPattern(int whatToShow, int axis, int axisForPredicate)
{
super(whatToShow);
m_axis = axis;
}
/**
* The target local name or psuedo name, for hash table lookup optimization.
* @serial
*/
String m_targetString; // only calculate on head
/**
* Calculate the local name or psuedo name of the node that this pattern will test,
* for hash table lookup optimization.
*
* @see com.sun.org.apache.xpath.internal.compiler.PsuedoNames
*/
public void calcTargetString()
{
int whatToShow = getWhatToShow();
switch (whatToShow)
{
case DTMFilter.SHOW_COMMENT :
m_targetString = PsuedoNames.PSEUDONAME_COMMENT;
break;
case DTMFilter.SHOW_TEXT :
case DTMFilter.SHOW_CDATA_SECTION :
case (DTMFilter.SHOW_TEXT | DTMFilter.SHOW_CDATA_SECTION) :
m_targetString = PsuedoNames.PSEUDONAME_TEXT;
break;
case DTMFilter.SHOW_ALL :
m_targetString = PsuedoNames.PSEUDONAME_ANY;
break;
case DTMFilter.SHOW_DOCUMENT :
case DTMFilter.SHOW_DOCUMENT | DTMFilter.SHOW_DOCUMENT_FRAGMENT :
m_targetString = PsuedoNames.PSEUDONAME_ROOT;
break;
case DTMFilter.SHOW_ELEMENT :
if (this.WILD == m_name)
m_targetString = PsuedoNames.PSEUDONAME_ANY;
else
m_targetString = m_name;
break;
default :
m_targetString = PsuedoNames.PSEUDONAME_ANY;
break;
}
}
/**
* Get the local name or psuedo name of the node that this pattern will test,
* for hash table lookup optimization.
*
*
* @return local name or psuedo name of the node.
* @see com.sun.org.apache.xpath.internal.compiler.PsuedoNames
*/
public String getTargetString()
{
return m_targetString;
}
/**
* Reference to nodetest and predicate for
* parent or ancestor.
* @serial
*/
StepPattern m_relativePathPattern;
/**
* This function is used to fixup variables from QNames to stack frame
* indexes at stylesheet build time.
* @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).
* @param globalsSize The number of variables in the global variable area.
*/
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
super.fixupVariables(vars, globalsSize);
if (null != m_predicates)
{
for (int i = 0; i < m_predicates.length; i++)
{
m_predicates[i].fixupVariables(vars, globalsSize);
}
}
if (null != m_relativePathPattern)
{
m_relativePathPattern.fixupVariables(vars, globalsSize);
}
}
/**
* Set the reference to nodetest and predicate for
* parent or ancestor.
*
*
* @param expr The relative pattern expression.
*/
public void setRelativePathPattern(StepPattern expr)
{
m_relativePathPattern = expr;
expr.exprSetParent(this);
calcScore();
}
/**
* Get the reference to nodetest and predicate for
* parent or ancestor.
*
*
* @return The relative pattern expression.
*/
public StepPattern getRelativePathPattern()
{
return m_relativePathPattern;
}
// /**
// * Set the list of predicate expressions for this pattern step.
// * @param predicates List of expression objects.
// */
// public void setPredicates(Expression[] predicates)
// {
// m_predicates = predicates;
// }
/**
* Set the list of predicate expressions for this pattern step.
* @return List of expression objects.
*/
public Expression[] getPredicates()
{
return m_predicates;
}
/**
* The list of predicate expressions for this pattern step.
* @serial
*/
Expression[] m_predicates;
/**
* Tell if this expression or it's subexpressions can traverse outside
* the current subtree.
*
* NOTE: Ancestors tests with predicates are problematic, and will require
* special treatment.
*
* @return true if traversal outside the context node's subtree can occur.
*/
public boolean canTraverseOutsideSubtree()
{
int n = getPredicateCount();
for (int i = 0; i < n; i++)
{
if (getPredicate(i).canTraverseOutsideSubtree())
return true;
}
return false;
}
/**
* Get a predicate expression.
*
*
* @param i The index of the predicate.
*
* @return A predicate expression.
*/
public Expression getPredicate(int i)
{
return m_predicates[i];
}
/**
* Get the number of predicates for this match pattern step.
*
*
* @return the number of predicates for this match pattern step.
*/
public final int getPredicateCount()
{
return (null == m_predicates) ? 0 : m_predicates.length;
}
/**
* Set the predicates for this match pattern step.
*
*
* @param predicates An array of expressions that define predicates
* for this step.
*/
public void setPredicates(Expression[] predicates)
{
m_predicates = predicates;
if(null != predicates)
{
for(int i = 0; i < predicates.length; i++)
{
predicates[i].exprSetParent(this);
}
}
calcScore();
}
/**
* Static calc of match score.
*/
public void calcScore()
{
if ((getPredicateCount() > 0) || (null != m_relativePathPattern))
{
m_score = SCORE_OTHER;
}
else
super.calcScore();
if (null == m_targetString)
calcTargetString();
}
/**
* Execute this pattern step, including predicates.
*
*
* @param xctxt XPath runtime context.
* @param currentNode The current node context.
*
* @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt, int currentNode)
throws javax.xml.transform.TransformerException
{
DTM dtm = xctxt.getDTM(currentNode);
if (dtm != null)
{
int expType = dtm.getExpandedTypeID(currentNode);
return execute(xctxt, currentNode, dtm, expType);
}
return NodeTest.SCORE_NONE;
}
/**
* Execute this pattern step, including predicates.
*
*
* @param xctxt XPath runtime context.
*
* @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt)
throws javax.xml.transform.TransformerException
{
return execute(xctxt, xctxt.getCurrentNode());
}
/**
* Execute an expression in the XPath runtime context, and return the
* result of the expression.
*
*
* @param xctxt The XPath runtime context.
* @param currentNode The currentNode.
* @param dtm The DTM of the current node.
* @param expType The expanded type ID of the current node.
*
* @return The result of the expression in the form of a <code>XObject.
*
* @throws javax.xml.transform.TransformerException if a runtime exception
* occurs.
*/
public XObject execute(
XPathContext xctxt, int currentNode, DTM dtm, int expType)
throws javax.xml.transform.TransformerException
{
if (m_whatToShow == NodeTest.SHOW_BYFUNCTION)
{
if (null != m_relativePathPattern)
{
return m_relativePathPattern.execute(xctxt);
}
else
return NodeTest.SCORE_NONE;
}
XObject score;
score = super.execute(xctxt, currentNode, dtm, expType);
if (score == NodeTest.SCORE_NONE)
return NodeTest.SCORE_NONE;
if (getPredicateCount() != 0)
{
if (!executePredicates(xctxt, dtm, currentNode))
return NodeTest.SCORE_NONE;
}
if (null != m_relativePathPattern)
return m_relativePathPattern.executeRelativePathPattern(xctxt, dtm,
currentNode);
return score;
}
/**
* New Method to check whether the current node satisfies a position predicate
*
* @param xctxt The XPath runtime context.
* @param predPos Which predicate we're evaluating of foo[1][2][3].
* @param dtm The DTM of the current node.
* @param context The currentNode.
* @param pos The position being requested, i.e. the value returned by
* m_predicates[predPos].execute(xctxt).
*
* @return true of the position of the context matches pos, false otherwise.
*/
private final boolean checkProximityPosition(XPathContext xctxt,
int predPos, DTM dtm, int context, int pos)
{
try
{
DTMAxisTraverser traverser =
dtm.getAxisTraverser(Axis.PRECEDINGSIBLING);
for (int child = traverser.first(context); DTM.NULL != child;
child = traverser.next(context, child))
{
try
{
xctxt.pushCurrentNode(child);
if (NodeTest.SCORE_NONE != super.execute(xctxt, child))
{
boolean pass = true;
try
{
xctxt.pushSubContextList(this);
for (int i = 0; i < predPos; i++)
{
xctxt.pushPredicatePos(i);
try
{
XObject pred = m_predicates[i].execute(xctxt);
try
{
if (XObject.CLASS_NUMBER == pred.getType())
{
throw new Error("Why: Should never have been called");
}
else if (!pred.boolWithSideEffects())
{
pass = false;
break;
}
}
finally
{
pred.detach();
}
}
finally
{
xctxt.popPredicatePos();
}
}
}
finally
{
xctxt.popSubContextList();
}
if (pass)
pos--;
if (pos < 1)
return false;
}
}
finally
{
xctxt.popCurrentNode();
}
}
}
catch (javax.xml.transform.TransformerException se)
{
// TODO: should keep throw sax exception...
throw new java.lang.RuntimeException(se.getMessage());
}
return (pos == 1);
}
/**
* Get the proximity position index of the current node based on this
* node test.
*
*
* @param xctxt XPath runtime context.
* @param predPos Which predicate we're evaluating of foo[1][2][3].
* @param findLast If true, don't terminate when the context node is found.
*
* @return the proximity position index of the current node based on the
* node test.
*/
private final int getProximityPosition(XPathContext xctxt, int predPos,
boolean findLast)
{
int pos = 0;
int context = xctxt.getCurrentNode();
DTM dtm = xctxt.getDTM(context);
int parent = dtm.getParent(context);
try
{
DTMAxisTraverser traverser = dtm.getAxisTraverser(Axis.CHILD);
for (int child = traverser.first(parent); DTM.NULL != child;
child = traverser.next(parent, child))
{
try
{
xctxt.pushCurrentNode(child);
if (NodeTest.SCORE_NONE != super.execute(xctxt, child))
{
boolean pass = true;
try
{
xctxt.pushSubContextList(this);
for (int i = 0; i < predPos; i++)
{
xctxt.pushPredicatePos(i);
try
{
XObject pred = m_predicates[i].execute(xctxt);
try
{
if (XObject.CLASS_NUMBER == pred.getType())
{
if ((pos + 1) != (int) pred.numWithSideEffects())
{
pass = false;
break;
}
}
else if (!pred.boolWithSideEffects())
{
pass = false;
break;
}
}
finally
{
pred.detach();
}
}
finally
{
xctxt.popPredicatePos();
}
}
}
finally
{
xctxt.popSubContextList();
}
if (pass)
pos++;
if (!findLast && child == context)
{
return pos;
}
}
}
finally
{
xctxt.popCurrentNode();
}
}
}
catch (javax.xml.transform.TransformerException se)
{
// TODO: should keep throw sax exception...
throw new java.lang.RuntimeException(se.getMessage());
}
return pos;
}
/**
* Get the proximity position index of the current node based on this
* node test.
*
*
* @param xctxt XPath runtime context.
*
* @return the proximity position index of the current node based on the
* node test.
*/
public int getProximityPosition(XPathContext xctxt)
{
return getProximityPosition(xctxt, xctxt.getPredicatePos(), false);
}
/**
* Get the count of the nodes that match the test, which is the proximity
* position of the last node that can pass this test in the sub context
* selection. In XSLT 1-based indexing, this count is the index of the last
* node.
*
*
* @param xctxt XPath runtime context.
*
* @return the count of the nodes that match the test.
*/
public int getLastPos(XPathContext xctxt)
{
return getProximityPosition(xctxt, xctxt.getPredicatePos(), true);
}
/**
* Execute the match pattern step relative to another step.
*
*
* @param xctxt The XPath runtime context.
* @param dtm The DTM of the current node.
* @param currentNode The current node context.
*
* @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
*
* @throws javax.xml.transform.TransformerException
*/
protected final XObject executeRelativePathPattern(
XPathContext xctxt, DTM dtm, int currentNode)
throws javax.xml.transform.TransformerException
{
XObject score = NodeTest.SCORE_NONE;
int context = currentNode;
DTMAxisTraverser traverser;
traverser = dtm.getAxisTraverser(m_axis);
for (int relative = traverser.first(context); DTM.NULL != relative;
relative = traverser.next(context, relative))
{
try
{
xctxt.pushCurrentNode(relative);
score = execute(xctxt);
if (score != NodeTest.SCORE_NONE)
break;
}
finally
{
xctxt.popCurrentNode();
}
}
return score;
}
/**
* Execute the predicates on this step to determine if the current node
* should be filtered or accepted.
*
* @param xctxt The XPath runtime context.
* @param dtm The DTM of the current node.
* @param currentNode The current node context.
*
* @return true if the node should be accepted, false otherwise.
*
* @throws javax.xml.transform.TransformerException
*/
protected final boolean executePredicates(
XPathContext xctxt, DTM dtm, int currentNode)
throws javax.xml.transform.TransformerException
{
boolean result = true;
boolean positionAlreadySeen = false;
int n = getPredicateCount();
try
{
xctxt.pushSubContextList(this);
for (int i = 0; i < n; i++)
{
xctxt.pushPredicatePos(i);
try
{
XObject pred = m_predicates[i].execute(xctxt);
try
{
if (XObject.CLASS_NUMBER == pred.getType())
{
int pos = (int) pred.num();
if (positionAlreadySeen)
{
result = (pos == 1);
break;
}
else
{
positionAlreadySeen = true;
if (!checkProximityPosition(xctxt, i, dtm, currentNode, pos))
{
result = false;
break;
}
}
}
else if (!pred.boolWithSideEffects())
{
result = false;
break;
}
}
finally
{
pred.detach();
}
}
finally
{
xctxt.popPredicatePos();
}
}
}
finally
{
xctxt.popSubContextList();
}
return result;
}
/**
* Get the string represenentation of this step for diagnostic purposes.
*
*
* @return A string representation of this step, built by reverse-engineering
* the contained info.
*/
public String toString()
{
StringBuffer buf = new StringBuffer();
for (StepPattern pat = this; pat != null; pat = pat.m_relativePathPattern)
{
if (pat != this)
buf.append("/");
buf.append(Axis.getNames(pat.m_axis));
buf.append("::");
if (0x000005000 == pat.m_whatToShow)
{
buf.append("doc()");
}
else if (DTMFilter.SHOW_BYFUNCTION == pat.m_whatToShow)
{
buf.append("function()");
}
else if (DTMFilter.SHOW_ALL == pat.m_whatToShow)
{
buf.append("node()");
}
else if (DTMFilter.SHOW_TEXT == pat.m_whatToShow)
{
buf.append("text()");
}
else if (DTMFilter.SHOW_PROCESSING_INSTRUCTION == pat.m_whatToShow)
{
buf.append("processing-instruction(");
if (null != pat.m_name)
{
buf.append(pat.m_name);
}
buf.append(")");
}
else if (DTMFilter.SHOW_COMMENT == pat.m_whatToShow)
{
buf.append("comment()");
}
else if (null != pat.m_name)
{
if (DTMFilter.SHOW_ATTRIBUTE == pat.m_whatToShow)
{
buf.append("@");
}
if (null != pat.m_namespace)
{
buf.append("{");
buf.append(pat.m_namespace);
buf.append("}");
}
buf.append(pat.m_name);
}
else if (DTMFilter.SHOW_ATTRIBUTE == pat.m_whatToShow)
{
buf.append("@");
}
else if ((DTMFilter.SHOW_DOCUMENT | DTMFilter.SHOW_DOCUMENT_FRAGMENT)
== pat.m_whatToShow)
{
buf.append("doc-root()");
}
else
{
buf.append('?').append(Integer.toHexString(pat.m_whatToShow));
}
if (null != pat.m_predicates)
{
for (int i = 0; i < pat.m_predicates.length; i++)
{
buf.append("[");
buf.append(pat.m_predicates[i]);
buf.append("]");
}
}
}
return buf.toString();
}
/** Set to true to send diagnostics about pattern matches to the consol. */
private static final boolean DEBUG_MATCHES = false;
/**
* Get the match score of the given node.
*
* @param xctxt The XPath runtime context.
* @param context The node to be tested.
*
* @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
* {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
*
* @throws javax.xml.transform.TransformerException
*/
public double getMatchScore(XPathContext xctxt, int context)
throws javax.xml.transform.TransformerException
{
xctxt.pushCurrentNode(context);
xctxt.pushCurrentExpressionNode(context);
try
{
XObject score = execute(xctxt);
return score.num();
}
finally
{
xctxt.popCurrentNode();
xctxt.popCurrentExpressionNode();
}
// return XPath.MATCH_SCORE_NONE;
}
/**
* Set the axis that this step should follow.
*
*
* @param axis The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
*/
public void setAxis(int axis)
{
m_axis = axis;
}
/**
* Get the axis that this step follows.
*
*
* @return The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
*/
public int getAxis()
{
return m_axis;
}
class PredOwner implements ExpressionOwner
{
int m_index;
PredOwner(int index)
{
m_index = index;
}
/**
* @see ExpressionOwner#getExpression()
*/
public Expression getExpression()
{
return m_predicates[m_index];
}
/**
* @see ExpressionOwner#setExpression(Expression)
*/
public void setExpression(Expression exp)
{
exp.exprSetParent(StepPattern.this);
m_predicates[m_index] = exp;
}
}
/**
* @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
*/
public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
{
if(visitor.visitMatchPattern(owner, this))
{
callSubtreeVisitors(visitor);
}
}
/**
* Call the visitors on the subtree. Factored out from callVisitors
* so it may be called by derived classes.
*/
protected void callSubtreeVisitors(XPathVisitor visitor)
{
if (null != m_predicates)
{
int n = m_predicates.length;
for (int i = 0; i < n; i++)
{
ExpressionOwner predOwner = new PredOwner(i);
if (visitor.visitPredicate(predOwner, m_predicates[i]))
{
m_predicates[i].callVisitors(predOwner, visitor);
}
}
}
if (null != m_relativePathPattern)
{
m_relativePathPattern.callVisitors(this, visitor);
}
}
/**
* @see ExpressionOwner#getExpression()
*/
public Expression getExpression()
{
return m_relativePathPattern;
}
/**
* @see ExpressionOwner#setExpression(Expression)
*/
public void setExpression(Expression exp)
{
exp.exprSetParent(this);
m_relativePathPattern = (StepPattern)exp;
}
/**
* @see Expression#deepEquals(Expression)
*/
public boolean deepEquals(Expression expr)
{
if(!super.deepEquals(expr))
return false;
StepPattern sp = (StepPattern)expr;
if (null != m_predicates)
{
int n = m_predicates.length;
if ((null == sp.m_predicates) || (sp.m_predicates.length != n))
return false;
for (int i = 0; i < n; i++)
{
if (!m_predicates[i].deepEquals(sp.m_predicates[i]))
return false;
}
}
else if (null != sp.m_predicates)
return false;
if(null != m_relativePathPattern)
{
if(!m_relativePathPattern.deepEquals(sp.m_relativePathPattern))
return false;
}
else if(sp.m_relativePathPattern != null)
return false;
return true;
}
}
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