AggComputer.h

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/*
// $Id: //open/dev/fennel/exec/AggComputer.h#10 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2005-2009 The Eigenbase Project
// Copyright (C) 2005-2009 SQLstream, Inc.
// Copyright (C) 2005-2009 LucidEra, Inc.
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version approved by The Eigenbase Project.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef Fennel_AggComputer_Included
#define Fennel_AggComputer_Included

#include <boost/ptr_container/ptr_vector.hpp>
#include "fennel/common/FemEnums.h"

FENNEL_BEGIN_NAMESPACE

class StoredTypeDescriptor;
class TupleAttributeDescriptor;
class TupleData;
class TupleDatum;

class FENNEL_EXEC_EXPORT AggComputer
{
protected:
    int iInputAttr;

public:
    explicit AggComputer();

    virtual ~AggComputer();

    static AggComputer *newAggComputer(
        AggFunction aggFunction,
        TupleAttributeDescriptor const *pAttrDesc);

    virtual void setInputAttrIndex(uint iInputAttrIndex);

    virtual void clearAccumulator(
        TupleDatum &accumulatorDatum) = 0;

    virtual void updateAccumulator(
        TupleDatum &accumulatorDatum,
        TupleData const &inputTuple) = 0;

    virtual void computeOutput(
        TupleDatum &outputDatum,
        TupleDatum const &accumulatorDatum) = 0;

    virtual void initAccumulator(
        TupleDatum &accumulatorDatumDest,
        TupleData const &inputTuple) = 0;

    virtual void initAccumulator(
        TupleDatum &accumulatorDatumSrc,
        TupleDatum &accumulatorDatumDest) = 0;

    virtual void updateAccumulator(
        TupleDatum &accumulatorDatumSrc,
        TupleDatum &accumulatorDatumDest,
        TupleData const &inputTuple) = 0;
};

typedef boost::ptr_vector<AggComputer> AggComputerList;
typedef boost::ptr_vector<AggComputer>::iterator AggComputerIter;
typedef boost::ptr_vector<AggComputer>::const_iterator AggComputerConstIter;

FENNEL_END_NAMESPACE

#endif

// End AggComputer.h

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