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Diffstat (limited to '3rdparty/clucene/src/CLucene/search/ChainedFilter.h')
| -rw-r--r-- | 3rdparty/clucene/src/CLucene/search/ChainedFilter.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/3rdparty/clucene/src/CLucene/search/ChainedFilter.h b/3rdparty/clucene/src/CLucene/search/ChainedFilter.h new file mode 100644 index 000000000..f4d9d0049 --- /dev/null +++ b/3rdparty/clucene/src/CLucene/search/ChainedFilter.h @@ -0,0 +1,86 @@ +/*------------------------------------------------------------------------------ +* Copyright (C) 2003-2006 Ben van Klinken and the CLucene Team +* +* Distributable under the terms of either the Apache License (Version 2.0) or +* the GNU Lesser General Public License, as specified in the COPYING file. +------------------------------------------------------------------------------*/ +#ifndef _lucene_search_ChainedFilter_ +#define _lucene_search_ChainedFilter_ + +#include "CLucene/index/IndexReader.h" +#include "CLucene/util/BitSet.h" +#include "CLucene/search/Filter.h" + +CL_NS_DEF(search) + +/* +Discussion - brian@unixpoet.com + +From ChainedFilter.java: + +... + +// First AND operation takes place against a completely false +// bitset and will always return zero results. Thanks to +// Daniel Armbrust for pointing this out and suggesting workaround. + +if (logic[0] == AND) +{ + result = (BitSet) chain[i].bits(reader).clone(); + ++i; +} + +... + +The observation is correct and it was buggy. The problem is that the same +issue remains for the ANDNOT logic op but with the inverse result: all bits +set to 1. The result of the other ops, i.e. OR, AND, XOR for the first filter +ends up just copying the bitset of the first filter (explicitly in the case of the AND). + +Why not do the same for the NAND? This will have the side effect of rendering the first op +in the logic array superflous - not a big problem. + +The only "problem" is that we will return different results then the Java +Lucene code - though I prefer CLucene to be a correct implementation and only maintain +API compat rather than full 100% compat with Lucene. +*/ +class ChainedFilter: public Filter +{ +public: + LUCENE_STATIC_CONSTANT(int, OR = 0); //set current bit if the chain is set OR if the filter bit is set + LUCENE_STATIC_CONSTANT(int, AND = 1); //set current bit if the chain is set AND the filter bit is set + LUCENE_STATIC_CONSTANT(int, ANDNOT = 2); //set current bit if the chain is not set AND the filter bit is not set + LUCENE_STATIC_CONSTANT(int, XOR = 3); //set current bit if the chain is set OR the filter bit is set BUT not both is set + + LUCENE_STATIC_CONSTANT(int, USER = 5); //add this value to user defined value, then override doUserChain + + LUCENE_STATIC_CONSTANT(int, DEFAULT = OR); + +protected: + Filter **filters; + int *logicArray; + int logic; + + ChainedFilter( const ChainedFilter& copy ); + CL_NS(util)::BitSet* bits( CL_NS(index)::IndexReader* reader, int logic ); + CL_NS(util)::BitSet* bits( CL_NS(index)::IndexReader* reader, int* logicArray ); + CL_NS(util)::BitSet* doChain( CL_NS(util)::BitSet* result, CL_NS(index)::IndexReader* reader, int logic, Filter* filter ); + + virtual void doUserChain( CL_NS(util)::BitSet* chain, CL_NS(util)::BitSet* filter, int logic ); + virtual const TCHAR* getLogicString(int logic); +public: + ChainedFilter( Filter** filters, int op = DEFAULT ); + ChainedFilter( Filter** filters, int* _array ); + virtual ~ChainedFilter(); + + /** Returns a BitSet with true for documents which should be permitted in + search results, and false for those that should not. */ + CL_NS(util)::BitSet* bits( CL_NS(index)::IndexReader* reader ); + + virtual Filter* clone() const; + + TCHAR* toString(); +}; + +CL_NS_END +#endif |