mariadb-columnstore-engine/utils/windowfunction/wf_count.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_count.cpp 3932 2013-06-25 16:08:10Z xlou $

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

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

#include "loggingid.h"
using namespace logging;

#include "idborderby.h"
using namespace ordering;

#include "calpontsystemcatalog.h"
using namespace execplan;

#include "windowfunctionstep.h"
using namespace joblist;

#include "wf_count.h"

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

  switch (ct)
  {
    case CalpontSystemCatalog::CHAR:
    case CalpontSystemCatalog::VARCHAR:
    case CalpontSystemCatalog::VARBINARY:
    {
      func.reset(new WF_count<utils::NullString>(id, name));
      break;
    }

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

  return func;
}

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

template <typename T>
void WF_count<T>::resetData()
{
  fCount = 0;
  fSet.clear();

  WindowFunctionType::resetData();
}

template <typename T>
void WF_count<T>::operator()(int64_t b, int64_t e, int64_t c)
{
  if ((fFrameUnit == WF__FRAME_ROWS) || (fPrev == -1) ||
      (!fPeer->operator()(getPointer(fRowData->at(c)), getPointer(fRowData->at(fPrev)))))
  {
    // for unbounded - current row special handling
    if (fPrev >= b && fPrev < c)
      b = c;
    else if (fPrev <= e && fPrev > c)
      e = c;

    // for count(*), the column is optimized out, index[1] does not exist.
    int64_t colIn = (fFunctionId == WF__COUNT_ASTERISK) ? 0 : fFieldIndex[1];

    // constant param will have fFieldIndex[1] of -1. Get value of constant param
    if (colIn == -1)
    {
      ConstantColumn* cc = static_cast<ConstantColumn*>(fConstantParms[0].get());

      if (cc)
      {
        bool isNull = false;
        cc->getIntVal(fRow, isNull);

        if (!isNull)
        {
          // constant, set fCount to row count
          fCount += e - b + 1;
        }
      }
    }
    else if (fFunctionId == WF__COUNT_ASTERISK)
    {
      // count(*), set fCount to row count
      fCount += e - b + 1;
    }
    else
    {
      for (int64_t i = b; i <= e; i++)
      {
        if (i % 1000 == 0 && fStep->cancelled())
          break;

        fRow.setData(getPointer(fRowData->at(i)));

        if (fRow.isNullValue(colIn) == true)
          continue;

        if (fFunctionId != WF__COUNT_DISTINCT)
        {
          fCount++;
        }
        else
        {
          T valIn;
          getValue(colIn, valIn);

          if (fSet.find(valIn) == fSet.end())
          {
            fCount++;

            if (fFunctionId == WF__COUNT_DISTINCT)
              fSet.insert(valIn);
          }
        }
      }
    }
  }

  setValue(CalpontSystemCatalog::BIGINT, b, e, c, &fCount);

  fPrev = c;
}

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

}  // namespace windowfunction