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:
    {
      decltype(datatypes::MAXDECIMALWIDTH) width = wc->functionParms()[0]->resultType().colWidth;
      if (width < datatypes::MAXDECIMALWIDTH)
      {
        if (ct == CalpontSystemCatalog::UDECIMAL)
          func.reset(new WF_nth_value<uint64_t>(id, name));
        else
          func.reset(new WF_nth_value<int64_t>(id, name));
      }
      else if (width == 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<utils::NullString>(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 windowfunction