xapian-core/backends/glass/glass_spellingwordslist.h

   1 /** @file
   2  * @brief A termlist containing all words which are spelling targets.
   3  */
   4 /* Copyright (C) 2005,2008,2009,2010,2011,2017,2024 Olly Betts
   5  * Copyright (C) 2007 Lemur Consulting Ltd
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or (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_GLASS_SPELLINGWORDSLIST_H
  23 #define XAPIAN_INCLUDED_GLASS_SPELLINGWORDSLIST_H
  24
  25 #include "backends/alltermslist.h"
  26 #include "glass_spelling.h"
  27 #include "glass_cursor.h"
  28
  29 class GlassDatabase;
  30
  31 class GlassSpellingWordsList : public AllTermsList {
  32     /// Copying is not allowed.
  33     GlassSpellingWordsList(const GlassSpellingWordsList &);
  34
  35     /// Assignment is not allowed.
  36     void operator=(const GlassSpellingWordsList &);
  37
  38     /// Keep a reference to our database to stop it being deleted.
  39     Xapian::Internal::intrusive_ptr<const GlassDatabase> database;
  40
  41     /** A cursor which runs through the spelling table reading termnames from
  42      *  the keys.
  43      */
  44     GlassCursor * cursor;
  45
  46     /** The term frequency of the term at the current position.
  47      *
  48      *  If this value is zero, then we haven't read the term frequency or
  49      *  collection frequency for the current term yet.  We need to call
  50      *  read_termfreq() to read these.
  51      */
  52     mutable Xapian::termcount termfreq;
  53
  54     /// Read and cache the term frequency.
  55     void read_termfreq() const;
  56
  57   public:
  58     GlassSpellingWordsList(Xapian::Internal::intrusive_ptr<const GlassDatabase> database_,
  59                            GlassCursor * cursor_)
  60             : database(database_), cursor(cursor_), termfreq(0) {
  61         // Seek to the entry before the first key with a "W" prefix, so the
  62         // first next() will advance us to the first such entry.
  63         cursor->find_entry(std::string("W", 1));
  64     }
  65
  66     /// Destructor.
  67     ~GlassSpellingWordsList();
  68
  69     Xapian::termcount get_approx_size() const;
  70
  71     /** Returns the term frequency of the current term.
  72      *
  73      *  Either next() or skip_to() must have been called before this
  74      *  method can be called.
  75      */
  76     Xapian::doccount get_termfreq() const;
  77
  78     /// Advance to the next term in the list.
  79     TermList * next();
  80
  81     /// Advance to the first term which is >= tname.
  82     TermList* skip_to(std::string_view tname);
  83 };
  84
  85 #endif /* XAPIAN_INCLUDED_GLASS_SPELLINGWORDSLIST_H */