src/xalanc/XSLT/CountersTable.cpp

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2004 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
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 *    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.
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 * 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 
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 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * 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, International
 * Business Machines, Inc., http://www.ibm.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
#include "CountersTable.hpp"



#include <algorithm>



#include "ElemNumber.hpp"
#include "StylesheetExecutionContext.hpp"



XALAN_CPP_NAMESPACE_BEGIN



inline void
appendBtoFList(
			CountersTable::NodeVectorType&			flist,
			const CountersTable::NodeVectorType&	blist)
{
	XALAN_USING_STD(back_inserter)
	XALAN_USING_STD(copy)

	flist.reserve(flist.size() + blist.size());

	copy(
		blist.rbegin(),
		blist.rend(),
		back_inserter(flist));
}



CountersTable::CountType
CountersTable::countNode(
			StylesheetExecutionContext&		support,
			const ElemNumber&				numberElem,
			XalanNode*						node)
{
	assert(numberElem.getID() < m_countersVector.size());

	CountType	count = 0;

	CounterVectorType&	counters = m_countersVector[numberElem.getID()];

	const CounterVectorType::size_type	nCounters = counters.size();

	XalanNode*	target = numberElem.getTargetNode(support, node);

	if(0 != target)
	{
		for(CounterVectorType::size_type i = 0; i < nCounters; i++)
		{    
			const Counter&	counter = counters[i];

			count = counter.getPreviouslyCounted(support, target);

			if(count > 0)
			{
				return count;
			}
		}

		// In the loop below, we collect the nodes in backwards doc order, so 
		// we don't have to do inserts, but then we store the nodes in forwards 
		// document order, so we don't have to insert nodes into that list, 
		// so that's what the appendBtoFList stuff is all about.  In cases 
		// of forward counting by one, this will mean a single node copy from 
		// the backwards list (m_newFound) to the forwards list
		// (counter.m_countNodes).
		count = 0;

		for(; 0 != target; target = numberElem.getPreviousNode(support, target))
		{   
			// First time in, we should not have to check for previous counts, 
			// since the original target node was already checked in the 
			// block above.
			if(0 != count)  
			{
				for(CounterVectorType::size_type i = 0; i < nCounters; ++i)
				{
					Counter&	counter = counters[i];

					const Counter::NodeVectorType::size_type	cacheLen = counter.m_countNodes.size();

					if(cacheLen > 0 && counter.m_countNodes[cacheLen - 1] == target)
					{
						count += cacheLen + counter.m_countNodesStartCount;

						if(cacheLen > 0)
						{
							appendBtoFList(counter.m_countNodes, m_newFound);
						}

						m_newFound.clear();

						return count;
					}
				}
			}

			m_newFound.push_back(target);

			++count;
		}

		// If we got to this point, then we didn't find a counter, so make 
		// one and add it to the list.
		counters.resize(counters.size() + 1);

		Counter&	counter = counters.back();

		counter.m_numberElem = &numberElem;

		appendBtoFList(counter.m_countNodes, m_newFound);

		m_newFound.clear();
	}

	return count;
}



Counter::CountType
Counter::getPreviouslyCounted(
		StylesheetExecutionContext&		executionContext,
		const XalanNode*				node) const
{
	const NodeVectorType::size_type		n = m_countNodes.size();

	CountType	result = 0;

	for(NodeVectorType::size_type i = n; i > 0; --i)
	{
		const XalanNode* const	countedNode = m_countNodes[i - 1];

		if(node == countedNode)
		{
			// Since the list is in backwards order, the count is 
			// how many are in the rest of the list.
			result = i + m_countNodesStartCount;

			break;
		}

		// Try to see if the given node falls after the counted node...
		// if it does, don't keep searching backwards.
		if(executionContext.isNodeAfter(*countedNode, *node))
		{
			break;
		}
	}

	return result;
}



XALAN_CPP_NAMESPACE_END