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secondo/Algebras/BTree2/op_get_no_cachehits.cpp
2026-01-23 17:03:45 +08:00

113 lines
2.7 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
----
//paragraph [1] Title: [{\Large \bf \begin{center}] [\end{center}}]
//paragraph [10] Footnote: [{\footnote{] [}}]
//[TOC] [\tableofcontents]
[1] Implementation of the get\_no\_cachehits Operator
[TOC]
0 Overview
1 Defines and includes
*/
#include "op_get_no_cachehits.h"
#include "ListUtils.h"
#include "QueryProcessor.h"
#include "BTree2.h"
#include <limits>
extern NestedList* nl;
extern QueryProcessor *qp;
namespace BTree2Algebra {
namespace Operators {
/*
2 Operator ~get\_no\_cachehits~
Signature is
----
get no cache hits: (btree2) --> (int)
----
2.1 TypeMapping for Operator ~get\_no\_cachehits~
*/
ListExpr get_no_cachehits::TypeMapping( ListExpr args){
if(nl->ListLength(args) != 1){
return listutils::typeError("Operator expects exactly one argument");
}
if(!listutils::isBTree2Description(nl->First(args))){
return listutils::typeError( "Operator expects a btree2 "
"object as argument.");
}
return (nl->SymbolAtom(CcInt::BasicType()));
}
/*
2.2 Valuemapping for Operator
*/
int
get_no_cachehits::ValueMapping(Word* args, Word& result, int message,
Word& local, Supplier s)
{
result = qp->ResultStorage(s);
BTree2* btree = (BTree2*)args[0].addr;
CcInt *res = (CcInt*) result.addr;
res->Set( true, btree->GetCacheHitCounter() );
return 0;
}
/*
2.3 Operator specification
*/
struct getNoCacheHitsInfo : OperatorInfo {
getNoCacheHitsInfo() : OperatorInfo()
{
name = "get_no_cachehits";
signature = "(btree2 Tk Td u) -> int";
syntax = "get_no_cachehits ( _ )";
meaning = "Returns the number of cache-hits in the btree2.";
example = "query get_no_cachehits (staedte_btree2)";
}
};
Operator get_no_cachehits::def( getNoCacheHitsInfo(),
get_no_cachehits::ValueMapping,
get_no_cachehits::TypeMapping);
}
}