xapian-core/matcher/multimatch.h

   1 /** @file multimatch.h
   2  * @brief class for performing a match
   3  */
   4 /* Copyright 1999,2000,2001 BrightStation PLC
   5  * Copyright 2002,2003,2004,2005,2006,2007,2009,2011,2013,2014,2015,2016 Olly Betts
   6  * Copyright 2009 Lemur Consulting Ltd
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of the
  11  * License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  21  * USA
  22  */
  23
  24 #ifndef OM_HGUARD_MULTIMATCH_H
  25 #define OM_HGUARD_MULTIMATCH_H
  26
  27 #include "submatch.h"
  28
  29 #include <vector>
  30
  31 #include "xapian/query.h"
  32 #include "xapian/weight.h"
  33
  34 class MultiMatch
  35 {
  36     private:
  37         /// Vector of the items.
  38         std::vector<Xapian::Internal::intrusive_ptr<SubMatch> > leaves;
  39
  40         const Xapian::Database db;
  41
  42         Xapian::Query query;
  43
  44         Xapian::doccount collapse_max;
  45
  46         Xapian::valueno collapse_key;
  47
  48         int percent_cutoff;
  49
  50         double weight_cutoff;
  51
  52         Xapian::Enquire::docid_order order;
  53
  54         Xapian::valueno sort_key;
  55
  56         Xapian::Enquire::Internal::sort_setting sort_by;
  57
  58         bool sort_value_forward;
  59
  60         double time_limit;
  61
  62         /// Weighting scheme
  63         const Xapian::Weight * weight;
  64
  65         /** Internal flag to note that w_max needs to be recalculated
  66          *  while query is running.
  67          */
  68         bool recalculate_w_max;
  69
  70         /** Is each sub-database remote? */
  71         vector<bool> is_remote;
  72
  73         /// The matchspies to use.
  74         const vector<Xapian::Internal::opt_intrusive_ptr<Xapian::MatchSpy>> & matchspies;
  75
  76         /** get the maxweight that the postlist pl may return, calling
  77          *  recalc_maxweight if recalculate_w_max is set, and unsetting it.
  78          *  Must only be called on the top of the postlist tree.
  79          */
  80         double getorrecalc_maxweight(PostList *pl);
  81
  82         /// Copying is not permitted.
  83         MultiMatch(const MultiMatch &);
  84
  85         /// Assignment is not permitted.
  86         void operator=(const MultiMatch &);
  87
  88     public:
  89         /** MultiMatch constructor.
  90          *
  91          *  @param db_       The database to use.
  92          *  @param query     The query
  93          *  @param qlen      The query length
  94          *  @param omrset    The relevance set (or NULL for no RSet)
  95          *  @param time_limit_ Seconds to reduce check_at_least after (or <= 0
  96          *                     for no limit)
  97          *  @param stats     The stats object to add our stats to.
  98          *  @param wtscheme  Weighting scheme
  99          *  @param matchspies_ Any the MatchSpy objects in use.
 100          *  @param have_sorter Is there a sorter in use?
 101          *  @param have_mdecider Is there a Xapian::MatchDecider in use?
 102          */
 103         MultiMatch(const Xapian::Database &db_,
 104                    const Xapian::Query & query,
 105                    Xapian::termcount qlen,
 106                    const Xapian::RSet * omrset,
 107                    Xapian::doccount collapse_max_,
 108                    Xapian::valueno collapse_key_,
 109                    int percent_cutoff_,
 110                    double weight_cutoff_,
 111                    Xapian::Enquire::docid_order order_,
 112                    Xapian::valueno sort_key_,
 113                    Xapian::Enquire::Internal::sort_setting sort_by_,
 114                    bool sort_value_forward_,
 115                    double time_limit_,
 116                    Xapian::Weight::Internal & stats,
 117                    const Xapian::Weight *wtscheme,
 118                    const vector<Xapian::Internal::opt_intrusive_ptr<Xapian::MatchSpy>> & matchspies_,
 119                    bool have_sorter, bool have_mdecider);
 120
 121         /** Run the match and generate an MSet object.
 122          *
 123          *  @param sorter    Xapian::KeyMaker functor (or NULL for no KeyMaker)
 124          */
 125         void get_mset(Xapian::doccount first,
 126                       Xapian::doccount maxitems,
 127                       Xapian::doccount check_at_least,
 128                       Xapian::MSet & mset,
 129                       Xapian::Weight::Internal & stats,
 130                       const Xapian::MatchDecider * mdecider,
 131                       const Xapian::KeyMaker * sorter);
 132
 133         /** Called by postlists to indicate that they've rearranged themselves
 134          *  and the maxweight now possible is smaller.
 135          */
 136         void recalc_maxweight() {
 137             recalculate_w_max = true;
 138         }
 139
 140         bool full_db_has_positions() const {
 141             return db.has_positions();
 142         }
 143 };
 144
 145 #endif /* OM_HGUARD_MULTIMATCH_H */