cpp/galago/include/BinOrderedBinnedRetrieval.hpp

   1
   2 //
   3 // BinOrderedBinnedRetrieval
   4 //
   5 // 5 January 2007 -- tds
   6 //
   7 // BSD License (http://galagosearch.org/license)
   8 //
   9
  10 #ifndef GALAGO_BINORDEREDBINNEDRETRIEVAL_HPP
  11 #define GALAGO_BINORDEREDBINNEDRETRIEVAL_HPP
  12
  13 #include "BinnedIndex.hpp"
  14 #include <vector>
  15 #include "indri/ScoredExtentResult.hpp"
  16 #include "BinOrderedBinnedIterator.hpp"
  17 #include <queue>
  18 #include "Accumulators.hpp"
  19 #include "Query.hpp"
  20 #include "Retrieval.hpp"
  21
  22 //
  23 // ScoredIterator
  24 //
  25
  26 class ScoredIterator {
  27 public:
  28     struct order {
  29         bool operator () ( const ScoredIterator* one, const ScoredIterator* two ) const {
  30             return one->maxScore < two->maxScore;
  31         }
  32     };
  33
  34     BinOrderedBinnedIterator* iterator;
  35     int index;
  36     int maxScore;
  37     int weight;
  38
  39     ScoredIterator( BinOrderedBinnedIterator* _iterator ) {
  40         iterator = _iterator;
  41         index = -1;
  42         weight = 1;
  43         maxScore = 0xffff;
  44     }
  45
  46     ~ScoredIterator() {
  47         delete iterator;
  48     }
  49
  50     bool operator< ( const ScoredIterator& other ) {
  51        return maxScore < other.maxScore;
  52     }
  53 };
  54
  55 class BinOrderedBinnedRetrieval : public Retrieval {
  56 private:
  57     typedef std::priority_queue<ScoredIterator*,
  58                                 std::vector<ScoredIterator*>,
  59                                 ScoredIterator::order> siter_queue;
  60
  61     BinnedIndex _index;
  62     indri::api::Parameters _parameters;
  63
  64     void _assignMaxScore( std::vector<ScoredIterator*>& iterators );
  65     void _assignMaxScore( ScoredIterator* iterator );
  66
  67     void _calculateQueryWeights( const BinnedIndex& index, std::vector<ScoredIterator*>& iterators, int binCount );
  68     void _loadQueue( siter_queue& queue, std::vector<ScoredIterator*>& iterators, Accumulators& accumulators );
  69     void _processExcessTerms( std::vector<ScoredIterator*>& iterators, Accumulators& accumulators );
  70     void _fetchIterators( std::vector<ScoredIterator*>& iterators, const std::vector<QueryTerm>& queryTerms );
  71
  72 public:
  73     void openRead( const std::string& indexPath );
  74     void close();
  75     std::string getDocument( int document );
  76
  77     std::vector<indri::api::ScoredExtentResult> runQuery( const std::vector<QueryTerm>& query, int requested, int threshold );
  78 };
  79
  80 #endif // GALAGO_BINORDEREDBINNEDRETRIEVAL_HPP
  81
  82
  83