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author | Constantin Jucovschi <cj@ubuntu.localdomain> | 2009-04-24 07:20:22 -0400 |
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committer | Constantin Jucovschi <cj@ubuntu.localdomain> | 2009-04-24 07:20:22 -0400 |
commit | 8f27e65bddd7d4b8515ce620fb485fdd78fcdf89 (patch) | |
tree | bd328a4dd4f92d32202241b5e3a7f36177792c5f /qlparser/qtjoiniterator.hh | |
download | rasdaman-upstream-8f27e65bddd7d4b8515ce620fb485fdd78fcdf89.tar.gz rasdaman-upstream-8f27e65bddd7d4b8515ce620fb485fdd78fcdf89.tar.xz rasdaman-upstream-8f27e65bddd7d4b8515ce620fb485fdd78fcdf89.zip |
Initial commitv8.0
Diffstat (limited to 'qlparser/qtjoiniterator.hh')
-rw-r--r-- | qlparser/qtjoiniterator.hh | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/qlparser/qtjoiniterator.hh b/qlparser/qtjoiniterator.hh new file mode 100644 index 0000000..ca1403f --- /dev/null +++ b/qlparser/qtjoiniterator.hh @@ -0,0 +1,120 @@ +#ifndef _QTJOINITERATOR_ +#define _QTJOINITERATOR_ + +#ifndef CPPSTDLIB +#include <ospace/string.h> // STL<ToolKit> +#else +#include <string> +#endif + +#include "qlparser/qtiterator.hh" +#include "qlparser/qtoperation.hh" + +/* +* This file is part of rasdaman community. +* +* Rasdaman community 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 3 of the License, or +* (at your option) any later version. +* +* Rasdaman community 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 rasdaman community. If not, see <http://www.gnu.org/licenses/>. +* +* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Peter Baumann / +rasdaman GmbH. +* +* For more information please see <http://www.rasdaman.org> +* or contact Peter Baumann via <baumann@rasdaman.com>. +*/ +/************************************************************* + * + * + * COMMENTS: + * + ************************************************************/ + +//@ManMemo: Module: {\bf qlparser} + +/*@Doc: + +An object of this class takes its inputs and computes a tupel for every element +of the cross product. The result is passed to the output stream. +The class represents the FROM part of a query. + +*/ + +class QtJoinIterator : public QtIterator +{ + public: + /// default constructor + QtJoinIterator(); + + /// constructor getting a pointer to the parent + QtJoinIterator( QtNode* node ); + + /// virtual destructor + virtual ~QtJoinIterator(); + + /// prints the tree + virtual void printTree( int tab, std::ostream& s = std::cout, QtChildType mode = QT_ALL_NODES ); + + /// prints the algebraic expression + virtual void printAlgebraicExpression( std::ostream& s = std::cout ); + + //@Man: Operations of the ONC protocol: + //@{ + /// + void open(); + /// + QtDataList* next(); + /** + According to the producer/consumer protocol of ONC streams, the {/tt next()} + method has to store the last tupel of the crossproduct and update it with a new + element everytime it is invoked. Than it makes a copy of the tupel and pass + it to the caller. + */ + /// + void close(); + /// + void reset(); + /// + //@} + + //@Man: Read/Write methods: + //@{ + /// + //inline virtual void setParents(); + //@} + + /// method for identification of nodes + inline virtual const QtNodeType getNodeType() const; + + /// type checking + virtual const QtTypeTuple& checkType(); + + private: + /// inidicates if the output stream is empty or not + bool outputStreamIsEmpty; + /** The output stream is empty if at least one of the input streams is empty. + In that case, the cross product has no elements. This is indicated + by the variable {\tt outputStreamIsEmpty} which is set in the method + {\tt open()}. + */ + + /// pointer to a copy of the last passed tupel + QtDataList* actualTupel; + + /// attribute for identification of nodes + static const QtNodeType nodeType; +}; + +#include "qlparser/qtjoiniterator.icc" + +#endif + |