mariadb-columnstore-engine/utils/windowfunction/frameboundrange.h

/* 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: frameboundrange.h 3868 2013-06-06 22:13:05Z xlou $

#pragma once

#include "framebound.h"

namespace windowfunction
{
/** @brief class FrameBoundRange
 *
 */
class FrameBoundRange : public FrameBound
{
 public:
  /** @brief FrameBoundRange constructor
   *  @param  t, frame type
   *  @param  a, order by sort spec: asc | desc
   *  @param  n, order by sort spec: null first | null last
   *  @param  v, order by column data type
   */
  explicit FrameBoundRange(int t = 0, bool a = true, bool n = true)
   : FrameBound(t), fAsc(a), fNullFirst(n), fIsZero(false){};

  /** @brief FrameBoundRange destructor
   */
  ~FrameBoundRange() override = default;

  /** @brief clone
   */
  FrameBound* clone() override
  {
    return nullptr;  // abstract class
  }

  /** @brief virtual void getBound
   */
  int64_t getBound(int64_t, int64_t, int64_t) override;

  const std::string toString() const override;

  void setTupleId(std::vector<uint64_t> ids)
  {
    fTupleId = ids;
  }
  std::vector<uint64_t> getTupleId() const
  {
    return fTupleId;
  }

  void setIndex(vector<int> idx)
  {
    fIndex = idx;
  }
  const std::vector<int>& getIndex() const
  {
    return fIndex;
  }

  void isZero(bool z)
  {
    fIsZero = z;
  }
  bool isZero() const
  {
    return fIsZero;
  }

 protected:
  // for range calculation
  // data, row meta data, order by column index, ascending | descending
  // [0]: order by; [1]: interval; [2]: [0] +/- [1]
  std::vector<uint64_t> fTupleId;
  std::vector<int> fIndex;

  // order by sort specification
  bool fAsc;
  bool fNullFirst;

  // in case expr evaluates to 0
  bool fIsZero;
};

/** @brief struct ValueType
 *
 */
template <typename T>
struct ValueType
{
  T fValue;
  bool fIsNull;

  // constructor
  ValueType() : fValue(0), fIsNull(false)
  {
  }
};

/** @brief class FrameBoundConstantRange
 *
 */
template <typename T>
class FrameBoundConstantRange : public FrameBoundRange
{
 public:
  /** @brief FrameBoundConstant constructor
   *  @param  t, frame type
   *  @param  a, order by sort spec: asc | desc
   *  @param  n, order by sort spec: null first | null last
   *  @param  c, constant value.  !! caller need to check NULL or negative value !!
   */
  explicit FrameBoundConstantRange(int t = 0, bool a = true, bool n = true, void* c = nullptr)
   : FrameBoundRange(t, a, n)
  {
    fValue.fIsNull = (c == nullptr);

    if (!fValue.fIsNull)
      fValue.fValue = *((T*)c);
  };

  /** @brief FrameBoundConstantRange destructor
   */
  ~FrameBoundConstantRange() override = default;

  /** @brief clone
   */
  FrameBound* clone() override
  {
    return new FrameBoundConstantRange(*this);
  }

  /** @brief virtual void getBound
   */
  int64_t getBound(int64_t, int64_t, int64_t) override;

  const std::string toString() const override;

 protected:
  // find the range offset
  // i: partition upper bound
  // j: current row
  // k: partition lower bound
  virtual int64_t getPrecedingOffset(int64_t j, int64_t i);
  virtual int64_t getFollowingOffset(int64_t j, int64_t k);

  // validate value is not negative
  virtual void validate()
  {
  }

  // get value at fIndex[x]
  void getValue(ValueType<T>&, int64_t);
  T getValueByType(int64_t);

  // order by column value type
  ValueType<T> fValue;
};

/** @brief class FrameBoundExpressionRange
 *
 */
template <typename T>
class FrameBoundExpressionRange : public FrameBoundConstantRange<T>
{
 public:
  /** @brief FrameBoundExpressionRange constructor
   *  @param  t, frame type
   *  @param  a, order by sort spec: asc | desc
   *  @param  n, order by sort spec: null first | null last
   */
  explicit FrameBoundExpressionRange(int t = 0, bool a = true, bool n = true)
   : FrameBoundConstantRange<T>(t, a, n){};

  /** @brief FrameBoundExpressionRange destructor
   */
  ~FrameBoundExpressionRange() override = default;

  /** @brief clone
   */
  FrameBound* clone() override
  {
    return new FrameBoundExpressionRange(*this);
  }

  /** @brief virtual void getBound
   */
  // int64_t getBound(int64_t, int64_t, int64_t);

  const std::string toString() const override;

 protected:
  // virtual in FrameBoundRange
  int64_t getPrecedingOffset(int64_t j, int64_t i) override;
  int64_t getFollowingOffset(int64_t j, int64_t k) override;

  // validate the expression is not negative
  void validate() override;
};

}  // namespace windowfunction