252 lines
6.1 KiB
C++
252 lines
6.1 KiB
C++
/*
|
|
----
|
|
This file is part of SECONDO.
|
|
|
|
Copyright (C) 2015,
|
|
Faculty of Mathematics and 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
|
|
----
|
|
|
|
|
|
//[$][\$]
|
|
|
|
|
|
1 Implementation of the secondo operators drelimport
|
|
|
|
*/
|
|
//#define DRELDEBUG
|
|
|
|
#include "NestedList.h"
|
|
#include "ListUtils.h"
|
|
#include "QueryProcessor.h"
|
|
#include "StandardTypes.h"
|
|
#include "SecParser.h"
|
|
|
|
#include "Algebras/Distributed2/CommandLogger.h"
|
|
#include "Algebras/Distributed2/Distributed2Algebra.h"
|
|
#include "Stream.h"
|
|
#include "Algebras/FText/FTextAlgebra.h"
|
|
|
|
#include "DRelHelpers.h"
|
|
#include "DRel.h"
|
|
|
|
extern NestedList* nl;
|
|
extern QueryProcessor* qp;
|
|
|
|
namespace drel {
|
|
|
|
/*
|
|
1.1 Type Mappings ~file2streamTM~
|
|
|
|
Type mapping of the operator file2stream
|
|
|
|
*/
|
|
ListExpr file2streamTM( ListExpr args ) {
|
|
|
|
std::string err = "string|text expected";
|
|
|
|
ListExpr arg1Type = nl->First( args );
|
|
|
|
if( !FText::checkType( arg1Type )
|
|
&& !CcString::checkType( arg1Type ) ) {
|
|
return listutils::typeError(
|
|
err + ": first argument is not a string or text" );
|
|
}
|
|
|
|
ListExpr resultType = nl->TwoElemList(
|
|
listutils::basicSymbol<Stream<Tuple>>( ),
|
|
nl->TwoElemList(
|
|
listutils::basicSymbol<Tuple>( ),
|
|
nl->OneElemList(
|
|
nl->TwoElemList(
|
|
nl->SymbolAtom( "Data" ),
|
|
listutils::basicSymbol<FText>( ) ) ) ) );
|
|
|
|
return resultType;
|
|
}
|
|
|
|
template<class R>
|
|
class FileReader {
|
|
public:
|
|
FileReader( std::string _file ) : file( _file ) {
|
|
|
|
f.open( file, std::ios::in );
|
|
|
|
SecondoCatalog* sc = SecondoSystem::GetCatalog();
|
|
tupleType = sc->NumericType(
|
|
nl->TwoElemList(
|
|
listutils::basicSymbol<Tuple>( ),
|
|
nl->OneElemList(
|
|
nl->TwoElemList(
|
|
nl->SymbolAtom( "Data" ),
|
|
listutils::basicSymbol<FText>( ) ) ) ) );
|
|
}
|
|
|
|
~FileReader() {
|
|
|
|
}
|
|
|
|
Tuple* getTuple( ) {
|
|
|
|
if( !f.is_open( ) ) {
|
|
return 0;
|
|
}
|
|
|
|
if( f.eof( ) ) {
|
|
f.close( );
|
|
return 0;
|
|
}
|
|
|
|
std::string line;
|
|
getline( f, line );
|
|
|
|
#ifdef DRELDEBUG
|
|
cout << "line: " << line << endl;
|
|
#endif
|
|
|
|
// skip empty lines
|
|
while( line == "" ) {
|
|
getline( f, line );
|
|
if( f.eof( ) ) {
|
|
f.close( );
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
Tuple* t = new Tuple( tupleType );
|
|
t->PutAttribute( 0, new FText( true, line ) );
|
|
|
|
return t;
|
|
}
|
|
|
|
private:
|
|
ListExpr tupleType;
|
|
std::string file;
|
|
std::ifstream f;
|
|
|
|
};
|
|
|
|
/*
|
|
1.2 Value Mapping ~file2streamVMT~
|
|
|
|
Reads a file and create a drel.
|
|
|
|
*/
|
|
template<class R>
|
|
int file2streamVMT( Word* args, Word& result, int message,
|
|
Word& local, Supplier s ) {
|
|
|
|
#ifdef DRELDEBUG
|
|
cout << "file2streamVMT" << endl;
|
|
#endif
|
|
|
|
FileReader<R>* reader = ( FileReader<R>* )local.addr;
|
|
|
|
switch(message) {
|
|
|
|
case OPEN: {
|
|
|
|
std::string filename = ( ( R* )args[ 0 ].addr )->GetValue( );
|
|
|
|
#ifdef DRELDEBUG
|
|
cout << "OPEN" << endl;
|
|
cout << "filename: " << filename << endl;
|
|
#endif
|
|
|
|
if ( reader ) {
|
|
delete reader;
|
|
}
|
|
|
|
local.addr = new FileReader<R>( filename );
|
|
|
|
return 0;
|
|
}
|
|
|
|
case REQUEST: {
|
|
|
|
#ifdef DRELDEBUG
|
|
cout << "REQUEST" << endl;
|
|
#endif
|
|
|
|
result.addr = reader ? reader->getTuple( ) : 0;
|
|
return result.addr ? YIELD : CANCEL;
|
|
}
|
|
|
|
case CLOSE: {
|
|
|
|
#ifdef DRELDEBUG
|
|
cout << "CLOSE" << endl;
|
|
#endif
|
|
|
|
if ( reader ) {
|
|
delete reader;
|
|
local.addr = 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
1.3 ValueMapping Array for file2stream
|
|
|
|
*/
|
|
ValueMapping file2streamVM[ ] = {
|
|
file2streamVMT<CcString>,
|
|
file2streamVMT<FText>
|
|
};
|
|
|
|
/*
|
|
1.4 Selection function for int file2stream
|
|
|
|
*/
|
|
int file2streamSelect( ListExpr args ) {
|
|
|
|
return CcString::checkType( nl->First( args ) ) ? 0 : 1;
|
|
}
|
|
|
|
/*
|
|
1.5 Specification for the operator int file2stream
|
|
|
|
*/
|
|
OperatorSpec file2streamSpec(
|
|
" string|text -> stream(tuple((Data text)))",
|
|
" file2stream(_)",
|
|
"Imports a file and create a stream with the schema "
|
|
"stream(tuple((Data text))). Each line in the file "
|
|
"represents a tuple in the result",
|
|
" query int file2stream(\"import.txt\")"
|
|
);
|
|
|
|
/*
|
|
1.6 Operator instance of the operator int file2stream
|
|
|
|
*/
|
|
Operator file2streamOp(
|
|
"file2stream",
|
|
file2streamSpec.getStr( ),
|
|
2,
|
|
file2streamVM,
|
|
file2streamSelect,
|
|
file2streamTM
|
|
);
|
|
|
|
} // end of namespace drel
|