CountersTable.hpp

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/*
 * 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.
 */
#if !defined(XALAN_COUNTERSTABLE_HEADER_GUARD_1357924680)
#define XALAN_COUNTERSTABLE_HEADER_GUARD_1357924680



// Base include file.  Must be first.
#include <xalanc/XSLT/XSLTDefinitions.hpp>



#include <xalanc/Include/XalanVector.hpp>




#include "xalanc/XPath/MutableNodeRefList.hpp"



XALAN_CPP_NAMESPACE_BEGIN



class ElemNumber;
class StylesheetExecutionContext;



/**
 * <meta name="usage" content="internal"/>
 * A class that does incremental counting for support of xsl:number.
 * This class stores a cache of counted nodes (m_countNodes). 
 * It tries to cache the counted nodes in document order... 
 * the node count is based on its position in the cache list 
 */
struct Counter
{
    typedef XalanSize_t     CountType;

    typedef XalanVector<XalanNode*>         NodeVectorType;

    /**
     * The start count from where m_countNodes counts 
     * from.  In other words, the count of a given node 
     * in the m_countNodes vector is node position + 
     * m_countNodesStartCount.
     */
    CountType           m_countNodesStartCount;

    /**
     * A vector of all nodes counted so far.
     */
    NodeVectorType      m_countNodes;

    /**
     * The node from where the counting starts.  This is needed to 
     * find a counter if the node being counted is not immediatly
     * found in the m_countNodes vector.
     */
    const XalanNode*    m_fromNode;

    /**
     * The owning xsl:number element.
     */
    const ElemNumber*   m_numberElem;

    /**
     * Construct a counter object.
     */
    Counter(
            MemoryManager&  theManager,
            const ElemNumber*   numberElem,
            NodeVectorType&     countNodes) :
        m_countNodesStartCount(0),
        m_countNodes(countNodes, theManager),
        m_fromNode(0),
        m_numberElem(numberElem)
    {
    }

    /**
     * Construct a counter object.
     */
    Counter(MemoryManager& theManager, const ElemNumber*    numberElem = 0) :
        m_countNodesStartCount(0),
        m_countNodes(theManager),
        m_fromNode(0),
        m_numberElem(numberElem)
    {
    }

    Counter(const Counter& other, MemoryManager& theManager) :
        m_countNodesStartCount(other.m_countNodesStartCount),
        m_countNodes(other.m_countNodes, theManager),
        m_fromNode(other.m_fromNode),
        m_numberElem(other.m_numberElem)
    {
    }

    /**
     * Try to find a node that was previously counted. If found, return a
     * positive integer that corresponds to the count.
     * @param node The node to be counted.
     * @returns The count of the node, or 0 if not found.
     */
    CountType
    getPreviouslyCounted(
            StylesheetExecutionContext&     support,
            const XalanNode*                node) const;

    /**
     * Get the last node in the list.
     */
    XalanNode*
    getLast() const
    {
        return m_countNodes.empty() == true ? 0 : m_countNodes.back();
    }

private:
    // Not implemented
    Counter();
    Counter(const Counter&);
};

XALAN_USES_MEMORY_MANAGER(Counter)

typedef XalanVector<Counter>                CounterVectorTypeDecl;
XALAN_USES_MEMORY_MANAGER(CounterVectorTypeDecl)

typedef XalanVector<CounterVectorTypeDecl>      ElemCounterVectorVectorTypeDecl;
XALAN_USES_MEMORY_MANAGER(ElemCounterVectorVectorTypeDecl)
/**
 * <meta name="usage" content="internal"/>
 * This is a table of counters, keyed by ElemNumber objects, each 
 * of which has a list of Counter objects.  This really isn't a true 
 * table, it is more like a list of lists (there must be a technical 
 * term for that...).
 */
class CountersTable
{
public:

    typedef Counter::CountType  CountType;

    typedef CounterVectorTypeDecl               CounterVectorType;
    typedef ElemCounterVectorVectorTypeDecl     ElemCounterVectorVectorType;

    typedef Counter::NodeVectorType             NodeVectorType;

    /**
     * Construct a CountersTable.
     */
    CountersTable(MemoryManager& theManager,
                    unsigned long       theSize = 0) :
        m_countersVector(theManager),
        m_newFound(theManager)
    {
        resize(theSize);
    };

    ~CountersTable()
    {
    }

    /**
     * Resize the table.  The must be done prior
     * to using the table, if the size was not past
     * in the constructor.
     *
     * @theSize The new size
     */
    void
    resize(unsigned long    theSize)
    {
        m_countersVector.resize(theSize);
    }

    /**
     * Count forward until the given node is found, or until 
     * we have looked to the given amount.
     *
     * @executionContext The current execution context;
     * @numberElem The executing ElemNumber
     * @node The node to count.
     * @return The node count, or 0 if not found.
     */
    CountType
    countNode(
            StylesheetExecutionContext&     executionContext,
            const ElemNumber&               numberElem,
            XalanNode*                      node);

    /**
     * Clear all cached data from the table.
     */
    void
    reset()
    {
        m_newFound.clear();

        m_countersVector.clear();
    }

private:
    // not implemented
    CountersTable();
    CountersTable(const CountersTable&);

    /**
     * A vector which holds counters for ElemNumber instances.
     */
    ElemCounterVectorVectorType     m_countersVector;


    /**
     * A vector to use as a temporary buffer.
     */
    NodeVectorType                  m_newFound;
};



XALAN_CPP_NAMESPACE_END



#endif  // !defined(XALAN_COUNTERSTABLE_HEADER_GUARD_1357924680)