91 lines
2.0 KiB
C++
91 lines
2.0 KiB
C++
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/*
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1.1 ~OperatorRead~
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This operator reads a tuple stream from a relation and requests its replica
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from the ~DBService~ if the relation is not available locally.
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----
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This file is part of SECONDO.
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Copyright (C) 2017,
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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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*/
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#ifndef ALGEBRAS_DBSERVICE_OPERATORREAD_HPP_
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#define ALGEBRAS_DBSERVICE_OPERATORREAD_HPP_
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#include "Operator.h"
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namespace DBService {
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/*
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1.1.1 Operator Specification
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*/
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struct ReadInfo: OperatorInfo
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{
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ReadInfo()
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{
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name = "read";
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signature = "rel(tuple) -> stream(tuple)";
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syntax = "read(rel)";
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meaning = "read a tuple stream from a relation and fall back to the "
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"replica provided by the DBService if necessary";
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example = "query read(Roads)";
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remark = "requires a DBService system";
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usesArgsInTypeMapping = false;
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}
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};
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/*
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1.1.1 Class Definition
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*/
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class OperatorRead
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{
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public:
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/*
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1.1.1.1 Type Mapping Function
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*/
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static ListExpr mapType(ListExpr nestedList);
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/*
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1.1.1.1 Value Mapping Function
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*/
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static int mapValue(Word* args,
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Word& result,
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int message,
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Word& local,
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Supplier s);
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};
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} /* namespace DBService */
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#endif /* ALGEBRAS_DBSERVICE_OPERATORREAD_HPP_ */
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