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Diffstat (limited to 'qlparser/qtselectioniterator.hh')
-rw-r--r-- | qlparser/qtselectioniterator.hh | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/qlparser/qtselectioniterator.hh b/qlparser/qtselectioniterator.hh new file mode 100644 index 0000000..d187e68 --- /dev/null +++ b/qlparser/qtselectioniterator.hh @@ -0,0 +1,119 @@ +#ifndef _QTSELECTIONITERATOR_ +#define _QTSELECTIONITERATOR_ + +#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 condition expression specified through a reference to +an instance of the QtOperation sub-hierarchy, is evaluated for the actual input +The boolean result determines if the tupel is passed to the output stream or not. +So the method {\tt next()} reads tupels from its inputs until one can be +passed to its caller. The class represents the WHERE condition in the query + +*/ + +class QtSelectionIterator : public QtIterator +{ + public: + /// default constructor + QtSelectionIterator(); + + /// constructor getting a pointer to the parent + QtSelectionIterator( QtNode* node ); + + /// virtual destructor + virtual ~QtSelectionIterator(); + + /// return childs of the node + virtual QtNodeList* getChilds( QtChildType flag ); + + /// method for query rewrite + inline virtual void setInput( QtOperation* child, QtOperation* input); + + /// optimizing load access +// virtual void preOptimize(); + /** + Trigger load optimization in the condition tree and pass the optimization step to + the input streams. + */ + + /// 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: + //@{ + /// + QtDataList* next(); + //@} + + //@Man: Read/Write methods: + //@{ + /// + //inline virtual void setParents(); + /// + inline void setConditionTree( QtOperation* operation ); + /// + inline QtOperation* getConditionTree(); + //@} + + /// method for identification of nodes + inline virtual const QtNodeType getNodeType() const; + + /// type checking + virtual const QtTypeTuple& checkType(); + + private: + /// pointer to a tree representing the where part of the query + QtOperation* conditionTree; + + /// attribute for identification of nodes + static const QtNodeType nodeType; +}; + +#include "qlparser/qtselectioniterator.icc" + +#endif + + |