xapian-core/matcher/localsubmatch.h

   1 /** @file
   2  *  @brief SubMatch class for a local database.
   3  */
   4 /* Copyright (C) 2006,2007,2009,2010,2011,2013,2014,2015,2016,2018 Olly Betts
   5  * Copyright (C) 2007 Lemur Consulting Ltd
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  20  */
  21
  22 #ifndef XAPIAN_INCLUDED_LOCALSUBMATCH_H
  23 #define XAPIAN_INCLUDED_LOCALSUBMATCH_H
  24
  25 #include "backends/database.h"
  26 #include "debuglog.h"
  27 #include "api/leafpostlist.h"
  28 #include "api/queryinternal.h"
  29 #include "submatch.h"
  30 #include "xapian/enquire.h"
  31 #include "xapian/weight.h"
  32
  33 #include <map>
  34
  35 class LeafPostList;
  36
  37 class LocalSubMatch : public SubMatch {
  38     /// Don't allow assignment.
  39     void operator=(const LocalSubMatch &);
  40
  41     /// Don't allow copying.
  42     LocalSubMatch(const LocalSubMatch &);
  43
  44     /// The statistics for the collection.
  45     Xapian::Weight::Internal * stats;
  46
  47     /// The query.
  48     Xapian::Query query;
  49
  50     /// The query length (used by some weighting schemes).
  51     Xapian::termcount qlen;
  52
  53     /// The (sub-)Database we're searching.
  54     const Xapian::Database::Internal *db;
  55
  56     /** The RSet (used to calculate R and r).
  57      *
  58      *  R and r are used in probabilistic weighting formulae.
  59      */
  60     Xapian::RSet rset;
  61
  62     /// Weight object (used as a factory by calling create on it).
  63     const Xapian::Weight * wt_factory;
  64
  65     /// 0-based index for the subdatabase.
  66     Xapian::doccount shard_index;
  67
  68   public:
  69     /// Constructor.
  70     LocalSubMatch(const Xapian::Database::Internal *db_,
  71                   const Xapian::Query & query_,
  72                   Xapian::termcount qlen_,
  73                   const Xapian::RSet & rset_,
  74                   const Xapian::Weight* wt_factory_,
  75                   Xapian::doccount shard_index_)
  76         : stats(NULL), query(query_), qlen(qlen_), db(db_), rset(rset_),
  77           wt_factory(wt_factory_),
  78           shard_index(shard_index_)
  79     {
  80         LOGCALL_CTOR(MATCH, "LocalSubMatch", db_ | query_ | qlen_ | rset_ | wt_factory_);
  81     }
  82
  83     /// Fetch and collate statistics.
  84     bool prepare_match(bool nowait, Xapian::Weight::Internal & total_stats);
  85
  86     /// Start the match.
  87     void start_match(Xapian::doccount first,
  88                      Xapian::doccount maxitems,
  89                      Xapian::doccount check_at_least,
  90                      Xapian::Weight::Internal & total_stats);
  91
  92     /// Get PostList.
  93     PostList * get_postlist(MultiMatch *matcher,
  94                             Xapian::termcount* total_subqs_ptr,
  95                             Xapian::Weight::Internal& total_stats);
  96
  97     /** Convert a postlist into a synonym postlist.
  98      */
  99     PostList * make_synonym_postlist(PostList * or_pl, MultiMatch * matcher,
 100                                      double factor,
 101                                      bool wdf_disjoint);
 102
 103     LeafPostList * open_post_list(const std::string& term,
 104                                   Xapian::termcount wqf,
 105                                   double factor,
 106                                   bool need_positions,
 107                                   bool in_synonym,
 108                                   QueryOptimiser * qopt,
 109                                   bool lazy_weight);
 110 };
 111
 112 #endif /* XAPIAN_INCLUDED_LOCALSUBMATCH_H */