Files
secondo/Algebras/CRel/Operators/Rename.cpp
2026-01-23 17:03:45 +08:00

128 lines
2.9 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 "Rename.h"
#include <cstdint>
#include "ListUtils.h"
#include "LogMsg.h"
#include "OperatorUtils.h"
#include "QueryProcessor.h"
#include <string>
#include "StreamValueMapping.h"
#include "Symbols.h"
#include "../TypeConstructors/TBlockTC.h"
#include "TypeUtils.h"
using namespace CRelAlgebra;
using namespace CRelAlgebra::Operators;
using listutils::isStream;
using listutils::isValidAttributeName;
using std::string;
extern NestedList *nl;
extern QueryProcessor *qp;
Rename::Rename() :
Operator(info, StreamValueMapping<State>, TypeMapping)
{
}
const OperatorInfo Rename::info = OperatorInfo(
"rename", "stream(tblock) x symbol -> stream(tblock)",
"_ rename[ _ ]",
"Transforms a stream of tuple-blocks into one to which's column names the "
"specified suffix got appended.",
"");
ListExpr Rename::TypeMapping(ListExpr args)
{
if (!nl->HasLength(args, 2))
{
return GetTypeError("Expected two arguments.");
}
ListExpr stream = nl->First(args);
if (!isStream(stream))
{
return GetTypeError(0, "Isn't a stream.");
}
const ListExpr tblock = GetStreamType(stream);
if (!TBlockTI::Check(tblock))
{
return GetTypeError(0, "Isn't a stream of tblock.");
}
const ListExpr suffixExpr = nl->Second(args);
if (!nl->IsNodeType(SymbolType, suffixExpr))
{
return GetTypeError(1, "Isn't a symbol.");
}
const string suffix = nl->SymbolValue(suffixExpr);
string error;
TBlockTI blockInfo(tblock, false);
const uint64_t blockAttributeCount = blockInfo.columnInfos.size();
for (uint64_t i = 0; i < blockAttributeCount; ++i)
{
const string name = blockInfo.columnInfos[i].name + "_" + suffix;
if (!isValidAttributeName(nl->SymbolAtom(name), error))
{
return GetTypeError("Resulting attribute name '" + name + "' is not "
"valid");
}
blockInfo.columnInfos[i].name = name;
}
return blockInfo.GetTypeExpr(true);
}
Rename::State::State(Word* args, Supplier s) :
m_stream(args[0])
{
qp->DeleteResultStorage(s);
m_stream.open();
}
Rename::State::~State()
{
m_stream.close();
}
TBlock *Rename::State::Request()
{
return m_stream.request();
}