src/com/sun/org/apache/xpath/internal/axes/WalkingIterator.java - platform/external/jetbrains/jdk8u_jaxp - Git at Google

 /*
  * reserved comment block
  * 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: WalkingIterator.java,v 1.2.4.2 2005/09/14 19:45:19 jeffsuttor Exp $
  */
 package com.sun.org.apache.xpath.internal.axes;

 import com.sun.org.apache.xml.internal.dtm.DTM;
 import com.sun.org.apache.xml.internal.utils.PrefixResolver;
 import com.sun.org.apache.xpath.internal.Expression;
 import com.sun.org.apache.xpath.internal.ExpressionOwner;
 import com.sun.org.apache.xpath.internal.VariableStack;
 import com.sun.org.apache.xpath.internal.XPathVisitor;
 import com.sun.org.apache.xpath.internal.compiler.Compiler;
 import com.sun.org.apache.xpath.internal.compiler.OpMap;

 /**
  * Location path iterator that uses Walkers.
  */

 public class WalkingIterator extends LocPathIterator implements ExpressionOwner
 {
     static final long serialVersionUID = 9110225941815665906L;
   /**
    * 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
    */
   WalkingIterator(
           Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
             throws javax.xml.transform.TransformerException
   {
     super(compiler, opPos, analysis, shouldLoadWalkers);

     int firstStepPos = OpMap.getFirstChildPos(opPos);

     if (shouldLoadWalkers)
     {
       m_firstWalker = WalkerFactory.loadWalkers(this, compiler, firstStepPos, 0);
       m_lastUsedWalker = m_firstWalker;
     }
   }

   /**
    * Create a WalkingIterator object.
    *
    * @param nscontext The namespace context for this iterator,
    * should be OK if null.
    */
   public WalkingIterator(PrefixResolver nscontext)
   {

     super(nscontext);
   }


   /**
    * Get the analysis bits for this walker, as defined in the WalkerFactory.
    * @return One of WalkerFactory#BIT_DESCENDANT, etc.
    */
   public int getAnalysisBits()
   {
     int bits = 0;
     if (null != m_firstWalker)
     {
       AxesWalker walker = m_firstWalker;

       while (null != walker)
       {
         int bit = walker.getAnalysisBits();
         bits |= bit;
         walker = walker.getNextWalker();
       }
     }
     return bits;
   }

   /**
    * Get a cloned WalkingIterator 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
   {

     WalkingIterator clone = (WalkingIterator) super.clone();

     //    clone.m_varStackPos = this.m_varStackPos;
     //    clone.m_varStackContext = this.m_varStackContext;
     if (null != m_firstWalker)
     {
       clone.m_firstWalker = m_firstWalker.cloneDeep(clone, null);
     }

     return clone;
   }

   /**
    * Reset the iterator.
    */
   public void reset()
   {

     super.reset();

     if (null != m_firstWalker)
     {
       m_lastUsedWalker = m_firstWalker;

       m_firstWalker.setRoot(m_context);
     }

   }

   /**
    * 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);

     if(null != m_firstWalker)
     {
       m_firstWalker.setRoot(context);
       m_lastUsedWalker = m_firstWalker;
     }
   }

   /**
    *  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;

     // If the variable stack position is not -1, we'll have to
     // set our position in the variable stack, so our variable access
     // will be correct.  Iterators that are at the top level of the
     // expression need to reset the variable stack, while iterators
     // in predicates do not need to, and should not, since their execution
     // may be much later than top-level iterators.
     // m_varStackPos is set in setRoot, which is called
     // from the execute method.
     if (-1 == m_stackFrame)
     {
       return returnNextNode(m_firstWalker.nextNode());
     }
     else
     {
       VariableStack vars = m_execContext.getVarStack();

       // These three statements need to be combined into one operation.
       int savedStart = vars.getStackFrame();

       vars.setStackFrame(m_stackFrame);

       int n = returnNextNode(m_firstWalker.nextNode());

       // These two statements need to be combined into one operation.
       vars.setStackFrame(savedStart);

       return n;
     }
   }


   /**
    * Get the head of the walker list.
    *
    * @return The head of the walker list, or null
    * if this iterator does not implement walkers.
    * @xsl.usage advanced
    */
   public final AxesWalker getFirstWalker()
   {
     return m_firstWalker;
   }

   /**
    * Set the head of the walker list.
    *
    * @param walker Should be a valid AxesWalker.
    * @xsl.usage advanced
    */
   public final void setFirstWalker(AxesWalker walker)
   {
     m_firstWalker = walker;
   }


   /**
    * Set the last used walker.
    *
    * @param walker The last used walker, or null.
    * @xsl.usage advanced
    */
   public final void setLastUsedWalker(AxesWalker walker)
   {
     m_lastUsedWalker = walker;
   }

   /**
    * Get the last used walker.
    *
    * @return The last used walker, or null.
    * @xsl.usage advanced
    */
   public final AxesWalker getLastUsedWalker()
   {
     return m_lastUsedWalker;
   }

   /**
    *  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)
     {
                 AxesWalker walker = m_firstWalker;
             while (null != walker)
             {
               walker.detach();
               walker = walker.getNextWalker();
             }

             m_lastUsedWalker = null;

             // Always call the superclass detach last!
             super.detach();
     }
   }

   /**
    * 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).
    */
   public void fixupVariables(java.util.Vector vars, int globalsSize)
   {
     m_predicateIndex = -1;

     AxesWalker walker = m_firstWalker;

     while (null != walker)
     {
       walker.fixupVariables(vars, globalsSize);
       walker = walker.getNextWalker();
     }
   }

   /**
    * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
    */
   public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
   {
                 if(visitor.visitLocationPath(owner, this))
                 {
                         if(null != m_firstWalker)
                         {
                                 m_firstWalker.callVisitors(this, visitor);
                         }
                 }
   }


   /** The last used step walker in the walker list.
    *  @serial */
   protected AxesWalker m_lastUsedWalker;

   /** The head of the step walker list.
    *  @serial */
   protected AxesWalker m_firstWalker;

   /**
    * @see ExpressionOwner#getExpression()
    */
   public Expression getExpression()
   {
     return m_firstWalker;
   }

   /**
    * @see ExpressionOwner#setExpression(Expression)
    */
   public void setExpression(Expression exp)
   {
         exp.exprSetParent(this);
         m_firstWalker = (AxesWalker)exp;
   }

     /**
      * @see Expression#deepEquals(Expression)
      */
     public boolean deepEquals(Expression expr)
     {
       if (!super.deepEquals(expr))
                 return false;

       AxesWalker walker1 = m_firstWalker;
       AxesWalker walker2 = ((WalkingIterator)expr).m_firstWalker;
       while ((null != walker1) && (null != walker2))
       {
         if(!walker1.deepEquals(walker2))
                 return false;
         walker1 = walker1.getNextWalker();
         walker2 = walker2.getNextWalker();
       }

       if((null != walker1) || (null != walker2))
         return false;

       return true;
     }

 }
	/*
	* reserved comment block
	* 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: WalkingIterator.java,v 1.2.4.2 2005/09/14 19:45:19 jeffsuttor Exp $
	*/
	package com.sun.org.apache.xpath.internal.axes;

	import com.sun.org.apache.xml.internal.dtm.DTM;
	import com.sun.org.apache.xml.internal.utils.PrefixResolver;
	import com.sun.org.apache.xpath.internal.Expression;
	import com.sun.org.apache.xpath.internal.ExpressionOwner;
	import com.sun.org.apache.xpath.internal.VariableStack;
	import com.sun.org.apache.xpath.internal.XPathVisitor;
	import com.sun.org.apache.xpath.internal.compiler.Compiler;
	import com.sun.org.apache.xpath.internal.compiler.OpMap;

	/**
	* Location path iterator that uses Walkers.
	*/

	public class WalkingIterator extends LocPathIterator implements ExpressionOwner
	{
	static final long serialVersionUID = 9110225941815665906L;
	/**
	* 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
	*/
	WalkingIterator(
	Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
	throws javax.xml.transform.TransformerException
	{
	super(compiler, opPos, analysis, shouldLoadWalkers);

	int firstStepPos = OpMap.getFirstChildPos(opPos);

	if (shouldLoadWalkers)
	{
	m_firstWalker = WalkerFactory.loadWalkers(this, compiler, firstStepPos, 0);
	m_lastUsedWalker = m_firstWalker;
	}
	}

	/**
	* Create a WalkingIterator object.
	*
	* @param nscontext The namespace context for this iterator,
	* should be OK if null.
	*/
	public WalkingIterator(PrefixResolver nscontext)
	{

	super(nscontext);
	}


	/**
	* Get the analysis bits for this walker, as defined in the WalkerFactory.
	* @return One of WalkerFactory#BIT_DESCENDANT, etc.
	*/
	public int getAnalysisBits()
	{
	int bits = 0;
	if (null != m_firstWalker)
	{
	AxesWalker walker = m_firstWalker;

	while (null != walker)
	{
	int bit = walker.getAnalysisBits();
	bits \|= bit;
	walker = walker.getNextWalker();
	}
	}
	return bits;
	}

	/**
	* Get a cloned WalkingIterator 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
	{

	WalkingIterator clone = (WalkingIterator) super.clone();

	// clone.m_varStackPos = this.m_varStackPos;
	// clone.m_varStackContext = this.m_varStackContext;
	if (null != m_firstWalker)
	{
	clone.m_firstWalker = m_firstWalker.cloneDeep(clone, null);
	}

	return clone;
	}

	/**
	* Reset the iterator.
	*/
	public void reset()
	{

	super.reset();

	if (null != m_firstWalker)
	{
	m_lastUsedWalker = m_firstWalker;

	m_firstWalker.setRoot(m_context);
	}

	}

	/**
	* 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);

	if(null != m_firstWalker)
	{
	m_firstWalker.setRoot(context);
	m_lastUsedWalker = m_firstWalker;
	}
	}

	/**
	* 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;

	// If the variable stack position is not -1, we'll have to
	// set our position in the variable stack, so our variable access
	// will be correct. Iterators that are at the top level of the
	// expression need to reset the variable stack, while iterators
	// in predicates do not need to, and should not, since their execution
	// may be much later than top-level iterators.
	// m_varStackPos is set in setRoot, which is called
	// from the execute method.
	if (-1 == m_stackFrame)
	{
	return returnNextNode(m_firstWalker.nextNode());
	}
	else
	{
	VariableStack vars = m_execContext.getVarStack();

	// These three statements need to be combined into one operation.
	int savedStart = vars.getStackFrame();

	vars.setStackFrame(m_stackFrame);

	int n = returnNextNode(m_firstWalker.nextNode());

	// These two statements need to be combined into one operation.
	vars.setStackFrame(savedStart);

	return n;
	}
	}


	/**
	* Get the head of the walker list.
	*
	* @return The head of the walker list, or null
	* if this iterator does not implement walkers.
	* @xsl.usage advanced
	*/
	public final AxesWalker getFirstWalker()
	{
	return m_firstWalker;
	}

	/**
	* Set the head of the walker list.
	*
	* @param walker Should be a valid AxesWalker.
	* @xsl.usage advanced
	*/
	public final void setFirstWalker(AxesWalker walker)
	{
	m_firstWalker = walker;
	}


	/**
	* Set the last used walker.
	*
	* @param walker The last used walker, or null.
	* @xsl.usage advanced
	*/
	public final void setLastUsedWalker(AxesWalker walker)
	{
	m_lastUsedWalker = walker;
	}

	/**
	* Get the last used walker.
	*
	* @return The last used walker, or null.
	* @xsl.usage advanced
	*/
	public final AxesWalker getLastUsedWalker()
	{
	return m_lastUsedWalker;
	}

	/**
	* 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)
	{
	AxesWalker walker = m_firstWalker;
	while (null != walker)
	{
	walker.detach();
	walker = walker.getNextWalker();
	}

	m_lastUsedWalker = null;

	// Always call the superclass detach last!
	super.detach();
	}
	}

	/**
	* 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).
	*/
	public void fixupVariables(java.util.Vector vars, int globalsSize)
	{
	m_predicateIndex = -1;

	AxesWalker walker = m_firstWalker;

	while (null != walker)
	{
	walker.fixupVariables(vars, globalsSize);
	walker = walker.getNextWalker();
	}
	}

	/**
	* @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
	*/
	public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
	{
	if(visitor.visitLocationPath(owner, this))
	{
	if(null != m_firstWalker)
	{
	m_firstWalker.callVisitors(this, visitor);
	}
	}
	}


	/** The last used step walker in the walker list.
	* @serial */
	protected AxesWalker m_lastUsedWalker;

	/** The head of the step walker list.
	* @serial */
	protected AxesWalker m_firstWalker;

	/**
	* @see ExpressionOwner#getExpression()
	*/
	public Expression getExpression()
	{
	return m_firstWalker;
	}

	/**
	* @see ExpressionOwner#setExpression(Expression)
	*/
	public void setExpression(Expression exp)
	{
	exp.exprSetParent(this);
	m_firstWalker = (AxesWalker)exp;
	}

	/**
	* @see Expression#deepEquals(Expression)
	*/
	public boolean deepEquals(Expression expr)
	{
	if (!super.deepEquals(expr))
	return false;

	AxesWalker walker1 = m_firstWalker;
	AxesWalker walker2 = ((WalkingIterator)expr).m_firstWalker;
	while ((null != walker1) && (null != walker2))
	{
	if(!walker1.deepEquals(walker2))
	return false;
	walker1 = walker1.getNextWalker();
	walker2 = walker2.getNextWalker();
	}

	if((null != walker1) \|\| (null != walker2))
	return false;

	return true;
	}

	}