mariadb-columnstore-engine/utils/windowfunction/wf_ntile.cpp

/* Copyright (C) 2014 InfiniDB, 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; version 2 of
   the License.

   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., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

//  $Id: wf_ntile.cpp 3932 2013-06-25 16:08:10Z xlou $


//#define NDEBUG
#include <cassert>
#include <cmath>
#include <sstream>
#include <iomanip>
using namespace std;

#include <boost/shared_ptr.hpp>
using namespace boost;

#include "loggingid.h"
#include "errorcodes.h"
#include "idberrorinfo.h"
using namespace logging;

#include "rowgroup.h"
using namespace rowgroup;

#include "idborderby.h"
using namespace ordering;

#include "joblisttypes.h"
#include "calpontsystemcatalog.h"
#include "constantcolumn.h"
using namespace execplan;

#include "windowfunctionstep.h"
using namespace joblist;

#include "wf_ntile.h"


namespace windowfunction
{


boost::shared_ptr<WindowFunctionType> WF_ntile::makeFunction(int id, const string& name, int ct, WindowFunctionColumn* wc)
{
    boost::shared_ptr<WindowFunctionType> func(new WF_ntile(id, name));
    return func;
}


WindowFunctionType* WF_ntile::clone() const
{
    return new WF_ntile(*this);
}


void WF_ntile::resetData()
{
    WindowFunctionType::resetData();
}


void WF_ntile::parseParms(const std::vector<execplan::SRCP>& parms)
{
    // parms[0]: nt
    ConstantColumn* cc = dynamic_cast<ConstantColumn*>(parms[0].get());

    if (cc != NULL)
    {
        fNtileNull = false;
        fNtile = cc->getIntVal(fRow, fNtileNull);  // row not used, no need to setData.

        if (!fNtileNull && fNtile <= 0)
        {
            ostringstream oss;
            oss << fNtile;
            throw IDBExcept(IDBErrorInfo::instance()->errorMsg(ERR_WF_ARG_OUT_OF_RANGE,
                            oss.str()), ERR_WF_ARG_OUT_OF_RANGE);
        }
    }
}


void WF_ntile::operator()(int64_t b, int64_t e, int64_t c)
{
    int64_t idx = fFieldIndex[1];

    if (idx != -1)
    {
        fRow.setData(getPointer(fRowData->at(b)));

        if (idx != -1)
        {
            double tmp = 1.0;
            fNtileNull = fRow.isNullValue(idx);

            if (!fNtileNull)
                implicit2T(idx, tmp, 0);

            if (!fNtileNull && tmp <= 0)
            {
                ostringstream oss;
                oss << tmp;
                throw IDBExcept(IDBErrorInfo::instance()->errorMsg(ERR_WF_ARG_OUT_OF_RANGE,
                                oss.str()), ERR_WF_ARG_OUT_OF_RANGE);
            }

            if (tmp > e) // prevent integer overflow
                tmp = e + 1;

            fNtile = (int64_t) tmp;
        }
    }

    c = b;

    if (!fNtileNull)
    {
        int64_t rowPerBucket = (e - b + 1) / fNtile;
        int64_t n = rowPerBucket * fNtile;
        int64_t x = (e - b + 1) - n; // extra
        int64_t y = 0;
        int64_t z = 0;

        while (c <= e)
        {
            if (c % 1000 == 0 && fStep->cancelled())
                break;

            y = rowPerBucket + ((x-- > 0) ? 1 : 0);
            z++;

            for (int64_t i = 0; i < y && c <= e; i++)
            {
                fRow.setData(getPointer(fRowData->at(c++)));
                setIntValue(fFieldIndex[0], z);
            }
        }
    }
    else
    {
        while (c <= e)
        {
            if (c % 1000 == 0 && fStep->cancelled())
                break;

            fRow.setData(getPointer(fRowData->at(c++)));
            setIntValue(fFieldIndex[0], joblist::BIGINTNULL);
        }
    }
}


}   //namespace
// vim:ts=4 sw=4: