greenplumn CConstExprEvaluatorForDates 代码
文件路径：/src/backend/gporca/server/include/unittest/gpopt/CConstExprEvaluatorForDates.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2014 VMware, Inc. or its affiliates.
/
/ @filename:
/ CConstExprEvaluatorForDates.h
/
/ @doc:
/ Implementation of a constant expression evaluator for dates data
/
/ @owner:
/
/
/ @test:
/
/---------------------------------------------------------------------------
#ifndef GPOPT_CConstExprEvaluatorForDates_H
#define GPOPT_CConstExprEvaluatorForDates_H
#include "gpos/base.h"
#include "gpopt/eval/IConstExprEvaluator.h"
namespace gpopt
{
/ fwd declarations
class CExpression;
/---------------------------------------------------------------------------
/ @class:
/ CConstExprEvaluatorForDates
/
/ @doc:
/ Implementation of a constant expression evaluator for dates data.
/ It is meant to be used in Optimizer tests that have no access to
/ backend evaluator.
/
/---------------------------------------------------------------------------
class CConstExprEvaluatorForDates : public IConstExprEvaluator
{
private:
/ memory pool, not owned
CMemoryPool *m_mp;
public:
CConstExprEvaluatorForDates(const CConstExprEvaluatorForDates &) = delete;
/ ctor
explicit CConstExprEvaluatorForDates(CMemoryPool *mp) : m_mp(mp)
{
}
/ dtor
~CConstExprEvaluatorForDates() override = default;
/ evaluate the given expression and return the result as a new expression
/ caller takes ownership of returned expression
CExpression *PexprEval(CExpression *pexpr) override;
/ returns true iff the evaluator can evaluate constant expressions
BOOL
FCanEvalExpressions() override
{
return true;
}
}; / class CConstExprEvaluatorForDates
} / namespace gpopt
#endif / !GPOPT_CConstExprEvaluatorForDates_H
/ EOF