99 lines
2.5 KiB
C++
99 lines
2.5 KiB
C++
/*
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1.1 ~OperatorRderive~
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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. It allows passing
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a function that is executed on the replica so that only the matching tuples have
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to be transferred.
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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_OperatorRderive_HPP_
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#define ALGEBRAS_DBSERVICE_OperatorRderive_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 RderiveInfo: OperatorInfo
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{
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RderiveInfo()
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{
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name = "rderive";
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signature = "rel(X) x string x fun(rel(X) -> Y) -> Y";
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syntax = "rel rderive[string, fun]";
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meaning = "Create an object derived from a relation stored "
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"(replicated) by the DBService. The DBService "
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" determines the location of the replicas and "
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" creates the respective derived objects in "
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"the same locations. Useful for creating indexes on "
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"replicated relations. Relations with their indexes can then"
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" be accessed by read3 operations.";
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example = "query plz rderive[\"plz_ort_btree\", . createbtree[Ort]]";
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remark = "requires a DBService system";
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usesArgsInTypeMapping = true;
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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 OperatorRderive
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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_OPERATORRDERIVE_HPP */
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