65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
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/*
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----
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This file is part of SECONDO.
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Copyright (C) 2019,
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Faculty of Mathematics and Computer Science,
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Database Systems for New Applications.
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SECONDO is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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SECONDO is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with SECONDO; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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----
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//[<] [\ensuremath{<}]
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//[>] [\ensuremath{>}]
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*/
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#pragma once
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#include <vector>
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#include "Algebras/Relation-C++/RelationAlgebra.h"
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class TupleSmaller{
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public:
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TupleSmaller(const std::vector<std::pair<int,bool> >& _p): positions(_p){}
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bool operator()(Tuple* t1, Tuple* t2) const{
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for(size_t i=0;i<positions.size();i++){
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int c = t1->GetAttribute(positions[i].first)->
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Compare(t2->GetAttribute(positions[i].first));
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if(c < 0) return positions[i].second;
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if(c > 0) return !positions[i].second;
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}
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// tuples are equal
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return false;
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}
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private:
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std::vector<std::pair<int, bool> > positions;
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};
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class pc{
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public:
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pc(TupleSmaller _comp):comp(_comp){}
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bool operator()(const std::pair<Tuple*,TupleFileIterator*>& a,
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const std::pair<Tuple*, TupleFileIterator*>& b){
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return comp(a.first,b.first);
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}
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private:
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TupleSmaller comp;
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};
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