greenplumn CScalarConst 源码

greenplumn CScalarConst 代码

文件路径：/src/backend/gporca/libgpopt/src/operators/CScalarConst.cpp

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2011 EMC Corp.
//
//	@filename:
//		CScalarConst.cpp
//
//	@doc:
//		Implementation of scalar constant operator
//---------------------------------------------------------------------------

#include "gpopt/operators/CScalarConst.h"

#include "gpos/base.h"

#include "gpopt/base/CColRefSet.h"
#include "gpopt/base/CDrvdPropScalar.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "naucrates/base/IDatumBool.h"

using namespace gpopt;
using namespace gpnaucrates;
using namespace gpmd;

//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::CScalarConst
//
//	@doc:
//		Ctor
//
//---------------------------------------------------------------------------
CScalarConst::CScalarConst(CMemoryPool *mp, IDatum *datum)
	: CScalar(mp), m_pdatum(datum)
{
	GPOS_ASSERT(nullptr != datum);
}


//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::~CScalarConst
//
//	@doc:
//		Dtor
//
//---------------------------------------------------------------------------
CScalarConst::~CScalarConst()
{
	m_pdatum->Release();
}


//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::HashValue
//
//	@doc:
//		Operator specific hash function; combined hash of operator id and
//		hash of constant value
//
//---------------------------------------------------------------------------
ULONG
CScalarConst::HashValue() const
{
	return gpos::CombineHashes(COperator::HashValue(), m_pdatum->HashValue());
}

//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::Matches
//
//	@doc:
//		Match function on operator level
//
//---------------------------------------------------------------------------
BOOL
CScalarConst::Matches(COperator *pop) const
{
	if (pop->Eopid() == Eopid())
	{
		CScalarConst *psconst = CScalarConst::PopConvert(pop);

		// match if constant values are the same
		return GetDatum()->Matches(psconst->GetDatum());
	}

	return false;
}

//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::MdidType
//
//	@doc:
//		Expression type
//
//---------------------------------------------------------------------------
IMDId *
CScalarConst::MdidType() const
{
	return m_pdatum->MDId();
}


//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::OsPrint
//
//	@doc:
//		Debug print
//
//---------------------------------------------------------------------------
IOstream &
CScalarConst::OsPrint(IOstream &os) const
{
	os << SzId() << " (";
	m_pdatum->OsPrint(os);
	os << ")";
	return os;
}


//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::FCastedConst
//
//	@doc:
// 		Is the given expression a cast of a constant expression
//
//---------------------------------------------------------------------------
BOOL
CScalarConst::FCastedConst(CExpression *pexpr)
{
	GPOS_ASSERT(nullptr != pexpr);

	// cast(constant)
	if (COperator::EopScalarCast == pexpr->Pop()->Eopid())
	{
		if (COperator::EopScalarConst == (*pexpr)[0]->Pop()->Eopid())
		{
			return true;
		}
	}

	return false;
}


//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::PopExtractFromConstOrCastConst
//
//	@doc:
// 		Extract the constant from the given constant or a casted constant.
// 		Else return NULL.
//
//---------------------------------------------------------------------------
CScalarConst *
CScalarConst::PopExtractFromConstOrCastConst(CExpression *pexpr)
{
	GPOS_ASSERT(nullptr != pexpr);

	BOOL fScConst = COperator::EopScalarConst == pexpr->Pop()->Eopid();
	BOOL fCastedScConst = CScalarConst::FCastedConst(pexpr);

	// constant or cast(constant)
	if (!fScConst && !fCastedScConst)
	{
		return nullptr;
	}

	if (fScConst)
	{
		return CScalarConst::PopConvert(pexpr->Pop());
	}

	GPOS_ASSERT(fCastedScConst);

	return CScalarConst::PopConvert((*pexpr)[0]->Pop());
}

//---------------------------------------------------------------------------
//	@function:
//		CScalarConst::Eber
//
//	@doc:
//		Perform boolean expression evaluation
//
//---------------------------------------------------------------------------
CScalar::EBoolEvalResult
CScalarConst::Eber(ULongPtrArray *	//pdrgpulChildren
) const
{
	if (m_pdatum->IsNull())
	{
		return EberNull;
	}

	if (IMDType::EtiBool == m_pdatum->GetDatumType())
	{
		IDatumBool *pdatumBool = dynamic_cast<IDatumBool *>(m_pdatum);
		if (pdatumBool->GetValue())
		{
			return EberTrue;
		}

		return EberFalse;
	}

	return EberAny;
}

INT
CScalarConst::TypeModifier() const
{
	return m_pdatum->TypeModifier();
}


// EOF

相关信息

greenplumn 源码目录

相关文章

greenplumn CExpression 源码

greenplumn CExpressionFactorizer 源码

greenplumn CExpressionHandle 源码

greenplumn CExpressionPreprocessor 源码

greenplumn CExpressionUtils 源码

greenplumn CHashedDistributions 源码

greenplumn CLogical 源码

greenplumn CLogicalApply 源码

greenplumn CLogicalAssert 源码

greenplumn CLogicalBitmapTableGet 源码