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

/* Copyright (C) 2014 InfiniDB, Inc.
   Copyright (c) 2019 MariaDB Corporation

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

#include "windowfunctionstep.h"
using namespace joblist;

#include "wf_nth_value.h"


namespace windowfunction
{


template<typename T>
boost::shared_ptr<WindowFunctionType> WF_nth_value<T>::makeFunction(int id, const string& name, int ct, WindowFunctionColumn* wc)
{
    boost::shared_ptr<WindowFunctionType> func;

    switch (ct)
    {
        case CalpontSystemCatalog::TINYINT:
        case CalpontSystemCatalog::SMALLINT:
        case CalpontSystemCatalog::MEDINT:
        case CalpontSystemCatalog::INT:
        case CalpontSystemCatalog::BIGINT:
        {
            func.reset(new WF_nth_value<int64_t>(id, name));
            break;
        }

        case CalpontSystemCatalog::UTINYINT:
        case CalpontSystemCatalog::USMALLINT:
        case CalpontSystemCatalog::UMEDINT:
        case CalpontSystemCatalog::UINT:
        case CalpontSystemCatalog::UBIGINT:
        case CalpontSystemCatalog::DATE:
        case CalpontSystemCatalog::DATETIME:
        case CalpontSystemCatalog::TIMESTAMP:
        case CalpontSystemCatalog::TIME:
        {
            func.reset(new WF_nth_value<uint64_t>(id, name));
            break;
        }

        case CalpontSystemCatalog::DECIMAL:
        case CalpontSystemCatalog::UDECIMAL:
        {
            if (wc->functionParms()[0]->resultType().colWidth < datatypes::MAXDECIMALWIDTH)
            {
                func.reset(new WF_nth_value<int64_t>(id, name));
            }
            else if (wc->functionParms()[0]->resultType().colWidth == datatypes::MAXDECIMALWIDTH)
            {
                func.reset(new WF_nth_value<int128_t>(id, name));
            }
            break;
        }
        
        case CalpontSystemCatalog::DOUBLE:
        case CalpontSystemCatalog::UDOUBLE:
        {
            func.reset(new WF_nth_value<double>(id, name));
            break;
        }

        case CalpontSystemCatalog::FLOAT:
        case CalpontSystemCatalog::UFLOAT:
        {
            func.reset(new WF_nth_value<float>(id, name));
            break;
        }

        case CalpontSystemCatalog::LONGDOUBLE:
        {
            func.reset(new WF_nth_value<long double>(id, name));
            break;
        }

        default:
        {
            func.reset(new WF_nth_value<string>(id, name));
            break;
        }
    }

    return func;
}


template<typename T>
WindowFunctionType* WF_nth_value<T>::clone() const
{
    return new WF_nth_value<T>(*this);
}


template<typename T>
void WF_nth_value<T>::resetData()
{
    WindowFunctionType::resetData();
}


template<typename T>
void WF_nth_value<T>::parseParms(const std::vector<execplan::SRCP>& parms)
{
    // parms[0]: value-expr
    // skip

    // parms[1]: nth value
    ConstantColumn* cc = dynamic_cast<ConstantColumn*>(parms[1].get());

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

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

    // parms[2]: from first | from last
    bool isNull = false;
    cc = dynamic_cast<ConstantColumn*>(parms[2].get());
    idbassert(cc != NULL);
    fFromFirst = (cc->getIntVal(fRow, isNull) > 0);

    // parms[3]: respect null | ignore null
    cc = dynamic_cast<ConstantColumn*>(parms[3].get());
    idbassert(cc != NULL);
    fRespectNulls = (cc->getIntVal(fRow, isNull) > 0);
}


template<typename T>
void WF_nth_value<T>::operator()(int64_t b, int64_t e, int64_t c)
{
    int64_t s = b;
    int64_t t = e;

    if (c != WF__BOUND_ALL)
        s = t = c;

    for (int64_t c = s; c <= t; c++)
    {
        if (c % 1000 == 0 && fStep->cancelled())
            break;

        int64_t idx = fFieldIndex[2];
        fRow.setData(getPointer(fRowData->at(c)));

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

            if (!fNthNull)
            {
                implicit2T(idx, tmp, 0);
                fNth = round(tmp);
            }
        }

        bool isNull = true;

        if ((!fNthNull) && ((b + fNth - 1) <= e))
        {
            uint64_t colIn = fFieldIndex[1];

            if (fFromFirst)
            {
                int64_t k = b;
                fRow.setData(getPointer(fRowData->at(k)));

                if (fRespectNulls == false && fRow.isNullValue(colIn) == true)
                {
                    while (++k < e)
                    {
                        fRow.setData(getPointer(fRowData->at(k)));

                        if (fRow.isNullValue(colIn) == false)
                            break;
                    }
                }

                int64_t n = k + fNth - 1;

                if (n <= e && n >= 0)
                {
                    fRow.setData(getPointer(fRowData->at(n)));
                    getValue(colIn, fValue);
                    isNull = fRow.isNullValue(colIn);
                }
            }
            else    // from last
            {
                int64_t k = e;
                fRow.setData(getPointer(fRowData->at(k)));

                if (fRespectNulls == false && fRow.isNullValue(colIn) == true)
                {
                    while (--k > b)
                    {
                        fRow.setData(getPointer(fRowData->at(k)));

                        if (fRow.isNullValue(colIn) == false)
                            break;
                    }
                }

                int64_t n = k - fNth + 1;

                if (n >= b)
                {
                    fRow.setData(getPointer(fRowData->at(n)));
                    getValue(colIn, fValue);
                    isNull = fRow.isNullValue(colIn);
                }
            }
        }

        T* v = (isNull) ? NULL : &fValue;
        setValue(fRow.getColType(fFieldIndex[0]), b, e, c, v);
    }
}


template
boost::shared_ptr<WindowFunctionType> WF_nth_value<int64_t>::makeFunction(int, const string&, int, WindowFunctionColumn*);


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