LcsClusterReader.h

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/*
// $Id: //open/dev/fennel/lucidera/colstore/LcsClusterReader.h#11 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2005-2009 LucidEra, Inc.
// Copyright (C) 2005-2009 The Eigenbase Project
//
// 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_LcsClusterReader_Included
#define Fennel_LcsClusterReader_Included

#include "fennel/lucidera/colstore/LcsClusterAccessBase.h"
#include "fennel/lucidera/colstore/LcsClusterNode.h"
#include "fennel/lucidera/colstore/LcsColumnReader.h"
#include "fennel/btree/BTreeReader.h"
#include "fennel/tuple/TupleDescriptor.h"
#include "fennel/segment/SegPageEntryIter.h"
#include "fennel/segment/SegPageEntryIterSource.h"
#include <boost/scoped_array.hpp>

FENNEL_BEGIN_NAMESPACE

struct LcsRidRun
{
    LcsRid startRid;

    RecordNum nRids;
};

class FENNEL_LCS_EXPORT LcsClusterReader :
    public LcsClusterAccessBase, public SegPageEntryIterSource<LcsRid>
{
    friend class LcsColumnReader;

    SharedBTreeReader bTreeReader;

    PLcsBatchDir pRangeBatches;

    LcsRid rangeStartRid;

    LcsRid rangeEndRid;

    uint nRangePos;

    PBuffer pLeaf;

    PConstLcsClusterNode pLHdr;

    PLcsBatchDir pBatches;

    bool noPrefetch;

    CircularBufferIter<LcsRidRun> ridRunIter;

    SegPageEntryIter<LcsRid> prefetchQueue;

    LcsRid nextRid;

    std::pair<PageId, LcsRid> nextBTreeEntry;

    std::pair<PageId, LcsRid> nextPrefetchEntry;

    bool dumbPrefetch;

    LcsRid currRid;

    void moveToBlock(PageId clusterPageId);

    bool moveToBlockWithRid(LcsRid rid);

    bool positionInBlock(LcsRid rid);

    void positionInRange(uint pos)
    {
        nRangePos = pos;
    }

    void setUpBlock();

    LcsClusterNode const &readClusterPage();

    bool searchForRid(LcsRid rid);

    void getNextBTreeEntry();

public:
    uint nColsToRead;

    boost::scoped_array<LcsColumnReader> clusterCols;

    explicit LcsClusterReader(
        BTreeDescriptor const &treeDescriptor,
        CircularBuffer<LcsRidRun> *pRidRuns = NULL);

    virtual ~LcsClusterReader();

    void setRootPageId(PageId rootPageId);

    void initColumnReaders(
        uint nClusterColsInit,
        TupleProjection const &clusterProj);

    void open();

    void close();

    bool getFirstClusterPageForRead(PConstLcsClusterNode &pBlock);

    bool getNextClusterPageForRead(PConstLcsClusterNode &pBlock);

    inline bool isPositioned() const;

    inline LcsRid getRangeStartRid() const;

    inline LcsRid getRangeEndRid() const;

    inline uint getRangeSize() const;

    inline uint getRangePos() const;

    inline LcsRid getCurrentRid() const;

    inline uint getRangeRowsLeft() const;

    bool position(LcsRid rid);

    inline bool nextRange();

    bool advance(uint nRids);

    inline void advanceWithinBatch(uint nRids);

    virtual PageId getNextPageForPrefetch(LcsRid &rid, bool &found);

    static LcsRid getFetchRids(
        CircularBufferIter<LcsRidRun> &ridRunIter,
        LcsRid &nextRid,
        bool remove);

    void catchUp(uint parentBufPos, LcsRid parentNextRid);

    RecordNum getNumRows();
};

inline bool LcsClusterReader::isPositioned() const
{
    return pRangeBatches != NULL;
}

inline LcsRid LcsClusterReader::getRangeStartRid() const
{
    return rangeStartRid;
}

inline LcsRid LcsClusterReader::getRangeEndRid() const
{
    return rangeEndRid;
}

inline uint LcsClusterReader::getRangeSize() const
{
    return pRangeBatches->nRow;
}

inline uint LcsClusterReader::getRangePos() const
{
    return nRangePos;
}

inline LcsRid LcsClusterReader::getCurrentRid() const
{
    return getRangeStartRid() + getRangePos();
}

inline uint LcsClusterReader::getRangeRowsLeft() const
{
    return getRangeSize() - getRangePos();
}

inline bool LcsClusterReader::nextRange()
{
    return position(getRangeEndRid());
}

inline void LcsClusterReader::advanceWithinBatch(uint nRids)
{
    nRangePos = nRangePos + nRids;
}

FENNEL_END_NAMESPACE

#endif

// End LcsClusterReader.h

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