176 lines
4.4 KiB
C++
176 lines
4.4 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}}]
|
|
//characters [1] Type: [] []
|
|
//characters [2] Type: [] []
|
|
//[ae] [\"{a}]
|
|
//[oe] [\"{o}]
|
|
//[ue] [\"{u}]
|
|
//[ss] [{\ss}]
|
|
//[Ae] [\"{A}]
|
|
//[Oe] [\"{O}]
|
|
//[Ue] [\"{U}]
|
|
//[x] [$\times $]
|
|
//[->] [$\rightarrow $]
|
|
//[toc] [\tableofcontents]
|
|
|
|
[1] Implementation of operation transformtstream.
|
|
|
|
[toc]
|
|
|
|
1 Operation transformtstream implementation
|
|
|
|
*/
|
|
|
|
|
|
#include "Algebras/Relation-C++/RelationAlgebra.h"
|
|
#include "QueryProcessor.h"
|
|
#include "ListUtils.h"
|
|
#include "Stream.h"
|
|
|
|
#include "TupleDescr.h"
|
|
#include "VTuple.h"
|
|
#include "VTHelpers.h"
|
|
|
|
extern NestedList* nl;
|
|
extern QueryProcessor* qp;
|
|
extern AlgebraManager* am;
|
|
|
|
|
|
namespace cstream {
|
|
|
|
/*
|
|
1.1 Operation transformtstream ValueMapping
|
|
|
|
*/
|
|
|
|
int transformtstream_VM(Word* args, Word& result, int message,
|
|
Word& local, Supplier s) {
|
|
|
|
ListExpr* streamType = 0;
|
|
|
|
switch(message)
|
|
{
|
|
case OPEN:
|
|
{
|
|
LOG << " transformtstream: ValueMapping: OPEN " << ENDL;
|
|
qp->Open(args[0].addr);
|
|
// get stream type
|
|
Supplier son = qp->GetSon(s, 0);
|
|
streamType = new ListExpr(qp->GetType(son));
|
|
local.setAddr(streamType);
|
|
return 0;
|
|
}
|
|
|
|
case REQUEST:
|
|
{
|
|
LOG << " transformtstream: ValueMapping: REQUEST " << ENDL;
|
|
streamType = (ListExpr*)local.addr;
|
|
Word tupleword(Address(0));
|
|
qp->Request(args[0].addr, tupleword);
|
|
if (qp->Received(args[0].addr)) {
|
|
Tuple* tuple = static_cast<Tuple*>(tupleword.addr);
|
|
TupleDescr* td = new TupleDescr(
|
|
nl->Second(nl->Second(*streamType)));
|
|
VTuple* vt = new VTuple(tuple, td);
|
|
result = vt;
|
|
return YIELD;
|
|
} else {
|
|
result.addr = 0;
|
|
return CANCEL;
|
|
}
|
|
|
|
}
|
|
|
|
case CLOSE:
|
|
{
|
|
LOG << " transformtstream: ValueMapping: CLOSE " << ENDL;
|
|
if (local.addr != 0) {
|
|
streamType = (ListExpr*)local.addr;
|
|
delete streamType;
|
|
local.setAddr(0);
|
|
}
|
|
qp->Close(args[0].addr);
|
|
return 0;
|
|
}
|
|
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
1.2 Operation transformtstream TypeMapping
|
|
|
|
*/
|
|
|
|
ListExpr transformtstream_TM(ListExpr args) {
|
|
|
|
LOG << " transformtstream: TypeMapping" << ENDL;
|
|
LOG << " Argument of the Typemapping: " << nl->ToString(args) << ENDL;
|
|
|
|
if (nl->ListLength(args) != 1) {
|
|
return listutils::typeError("one argument expected");
|
|
}
|
|
|
|
// arg: stream of tuples
|
|
ListExpr arg = nl->First(args);
|
|
|
|
cout << nl->ToString(arg) << endl;
|
|
if (!listutils::isTupleStream(arg)) {
|
|
return listutils::typeError("stream(tuple(...)) expected");
|
|
}
|
|
|
|
return nl->TwoElemList(listutils::basicSymbol<Stream<VTuple> >(),
|
|
nl->OneElemList(listutils::basicSymbol<VTuple>()));
|
|
}
|
|
|
|
/*
|
|
1.3 Operation transformtstream operator specification
|
|
|
|
*/
|
|
|
|
const std::string transformtstreamOpSpec =
|
|
"( ( \"Signature\" \"Syntax\" \"Meaning\" \"Example\" ) "
|
|
"( <text>((stream (tuple([a1:d1, ... ,an:dn]))))"
|
|
" -> (stream (vtuple(tupledescr tuple([a1:d1, ... ,an:dn])))"
|
|
"</text--->"
|
|
"<text>_ transformtstream</text--->"
|
|
"<text>Transforms a tuple stream to a vtuple stream.</text--->"
|
|
"<text>query ten feed transformtstream feed transformvtstream consume</text--->"
|
|
") )";
|
|
|
|
/*
|
|
1.4 Operation transformtstream
|
|
|
|
*/
|
|
|
|
Operator transformtstream_Op(
|
|
"transformtstream",
|
|
transformtstreamOpSpec,
|
|
transformtstream_VM,
|
|
Operator::SimpleSelect,
|
|
transformtstream_TM
|
|
);
|
|
|
|
} /* end of namespace */
|