core/sql/exp/ExpCriDesc.h

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/* -*-C++-*-
****************************************************************************
*
* File:         ExpCriDesc.h (previously /executor/ex_cri_desc.h)
* Description:  Description of a row in the executor (number of tuples,
*               data types of the individual columns)
* Created:      5/6/98
* Language:     C++
*
*
*
****************************************************************************
*/

#ifndef EXP_CRI_DESC_H
#define EXP_CRI_DESC_H

// forward declarations
class ExpTupleDesc;
class ex_cri_desc;

#include "NAVersionedObject.h"
#include "exp_tuple_desc.h"

// ---------------------------------------------------------------------
// Template instantiation to produce a 64-bit pointer emulator class
// for ExCriDesc
// ---------------------------------------------------------------------
typedef NAVersionedObjectPtrTempl<ex_cri_desc> ExCriDescPtr;

//
// An ex_cri_desc is a data structure that describes what information
// is pointed to by an atp_struct.
// (atp = array of tupp pointers, cri = composite row instance)
// The two acronyms ATP and CRI are there for historical reasons, we
// use ex_cri_desc for the descriptive part and ATP for the actual data,
// but the underlying idea is the same.
//
// Each atp_struct has a pointer to a cri_desc followed by an array tupp
// pointers. The cri_desc describes the each of the tupps pointed to.
//


class ex_cri_desc : public NAVersionedObject
{
  enum {PACKED = 0x0001};

  // pointer to array
  ExpTupleDescPtrPtr tupleDesc_;        // 00-07
  UInt32             flags_;            // 08-11
  const UInt16       numTuples_;        // 12-13
  // ---------------------------------------------------------------------
  // Fillers for potential future extensions without changing class size.
  // When a new member is added, size of this filler should be reduced so
  // that the size of the object remains the same (and is modulo 8).
  // ---------------------------------------------------------------------
  char               fillers_[10];      // 14-23

public:

  ex_cri_desc(const unsigned short numTuples, void * space_); //constructor

  ex_cri_desc() : NAVersionedObject(-1), numTuples_(0) {}


  inline unsigned short noTuples() const;

  inline ExpTupleDesc * getTupleDescriptor(const unsigned short tupleNo) const;

  inline void setTupleDescriptor(const unsigned short tupleNo, ExpTupleDesc * tupleDesc);
  

  Long pack(void *);
  Lng32 unpack(void *, void * reallocator);

  void display(const char* title = "");
  
  // ---------------------------------------------------------------------
  // Redefinition of methods inherited from NAVersionedObject.
  // ---------------------------------------------------------------------
  virtual unsigned char getClassVersionID()
  {
    return 1;
  }

  virtual void populateImageVersionIDArray()
  {
    setImageVersionID(0,getClassVersionID());
  }

  virtual short getClassSize() { return (short)sizeof(*this); }
  // ---------------------------------------------------------------------
};  // descriptor for cri


inline unsigned short ex_cri_desc::noTuples() const
{
  return numTuples_;
};

inline ExpTupleDesc * ex_cri_desc::getTupleDescriptor(const unsigned short tupleNo) const
{
  // Don't use ex_assert since class is shared with generator.
  // ex_assert(tupleNo < numTuples_ , "ex_cri_desc::setTupleDescriptor() tuple index out of range");
  return tupleDesc_[tupleNo];
};

inline void ex_cri_desc::setTupleDescriptor(const unsigned short tupleNo,
                                            ExpTupleDesc * tupleDesc)
{
  // Don't use ex_assert since class is shared with generator.
  // ex_assert(tupleNo < numTuples_ , "ex_cri_desc::getTupleDescriptor() tuple index out of range");
  tupleDesc_[tupleNo] = tupleDesc;
};


#endif