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secondo/Algebras/NestedRelation2/Aconsume.cpp
2026-01-23 17:03:45 +08:00

83 lines
1.9 KiB
C++

/*
----
This file is part of SECONDO.
Copyright (C) 2004, University in Hagen, Department of Computer Science,
Database Systems for New Applications.
SECONDO 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; either version 2 of the License, or
(at your option) any later version.
SECONDO 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 SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
----
*/
#include "Include.h"
using namespace nr2a;
Aconsume::~Aconsume()
{
}
/*static*/ListExpr Aconsume::MapType(ListExpr args)
{
ListExpr result = nl->TypeError();
if ((nl->ListLength(args) == 1) && listutils::isStream(nl->First(args)))
{
result = nl->TwoElemList(nl->SymbolAtom(ARel::BasicType()),
nl->Second(nl->First(args)));
}
return result;
}
ValueMapping Aconsume::functions[] = { AconsumeValue, NULL };
/*static*/int Aconsume::SelectFunction(ListExpr args)
{
return 0;
}
/*
All provided tuples are added to the resulting attribute relation.
*/
/*static*/int Aconsume::AconsumeValue(Word* args, Word& result,
int message, Word& local, Supplier s)
{
Word w = qp->ResultStorage(s);
ARel* arel = (ARel*) (w.addr);
arel->Clear();
Stream<Tuple> stream(args[0]);
stream.open();
Tuple* tup;
while ((tup = stream.request()) != NULL)
{
arel->AppendTuple(tup);
}
stream.close();
result.setAddr(arel);
return 0;
}
/*
List of functions for cost estimation.
*/
CreateCostEstimation Aconsume::costEstimators[] =
{ BlockingProgressEstimator::Build };