LbmSegment.h

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/*
// $Id: //open/dev/fennel/lucidera/bitmap/LbmSegment.h#16 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2006-2009 LucidEra, Inc.
// Copyright (C) 2006-2009 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_LbmSegment_Included
#define Fennel_LbmSegment_Included

#include "fennel/lucidera/colstore/LcsClusterNode.h"

FENNEL_BEGIN_NAMESPACE

class FENNEL_LBM_EXPORT LbmSegment
    : public boost::noncopyable
{
protected:
    LcsRid startRID;

    PBuffer pSegDescStart;
    PBuffer pSegDescEnd;

    PBuffer pSegStart;
    PBuffer pSegEnd;

    static const uint LbmHalfByteSize = 4;

    static const uint8_t LbmSegLengthMask = 0xf0;

    static const uint8_t LbmZeroLengthMask = 0x0f;

    static const uint LbmZeroLengthCompact = 12;

    static const uint LbmZeroLengthExtended =
        (uint)LbmZeroLengthMask - LbmZeroLengthCompact;

    static const uint LbmMaxSegSize = 16;

    static uint byteArray2Value(PBuffer array, uint arraySize);

    static uint value2ByteArray(uint value, PBuffer array, uint arraySize);

    uint computeSpaceForZeroBytes(uint nZeroBytes);

    static void readSegDescAndAdvance(
        PBuffer &pSegDesc, uint &bmSegLen, uint &zeroBytes);

    uint computeSegLength(PBuffer segDesc);

    uint computeSegDescLength(PBuffer segDesc);

    uint countSegments();

public:
    static inline LcsRid roundToByteBoundary(LcsRid rid);

    static inline bool setSegLength(uint8_t &segDescByte, uint segLen);

    static inline bool adjustSegLength(uint8_t &segDescByte, uint segLen);

    static inline uint getSegLength(uint8_t segDescByte);

    inline uint getZeroLengthByteCount(uint8_t segDescByte);

    inline LcsRid getStartRID();

    static const uint LbmOneByteSize = 8;
    static const uint LbmOneByteSizeBitShift = 3;
    static const LcsRidPrimitive LbmOneByteSizeBitMask =
        0xfffffffffffffff8ULL;
};

inline LcsRid LbmSegment::roundToByteBoundary(LcsRid rid)
{
    return LcsRid(opaqueToInt(rid) & LbmOneByteSizeBitMask);
}

inline bool LbmSegment::setSegLength(uint8_t &segDescByte, uint segLen)
{
    if (segLen > LbmMaxSegSize) {
        return false;
    }
    segDescByte = (uint8_t) ((segLen - 1) << LbmHalfByteSize);
    return true;
}

inline bool LbmSegment::adjustSegLength(uint8_t &segDescByte, uint segLen)
{
    if (segLen > LbmMaxSegSize) {
        return false;
    }
    segDescByte &= ~LbmSegLengthMask;
    segDescByte |= (uint8_t) ((segLen - 1) << LbmHalfByteSize);
    return true;
}

inline uint LbmSegment::getSegLength(uint8_t segDescByte)
{
    return (((segDescByte & LbmSegLengthMask) >> LbmHalfByteSize) + 1);
}

inline uint LbmSegment::getZeroLengthByteCount(uint8_t segDescByte)
{
    uint lengthBytes = segDescByte & LbmZeroLengthMask;
    if (lengthBytes > LbmZeroLengthCompact) {
        return (lengthBytes - LbmZeroLengthCompact);
    } else {
        return 0;
    }
}

inline LcsRid LbmSegment::getStartRID()
{
    return startRID;
}

DEFINE_OPAQUE_INTEGER(LbmByteNumber, uint64_t);

inline LbmByteNumber ridToByteNumber(LcsRid rid)
{
    return LbmByteNumber(
        opaqueToInt(rid) >> LbmSegment::LbmOneByteSizeBitShift);
}

inline LcsRid byteNumberToRid(LbmByteNumber byteNum)
{
    return LcsRid(
        opaqueToInt(byteNum) << LbmSegment::LbmOneByteSizeBitShift);
}

FENNEL_END_NAMESPACE

#endif

// End LbmSegment.h

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