xapian-core/backends/honey/honey_spellingwordslist.h

   1 /** @file honey_spellingwordslist.h
   2  * @brief A termlist containing all words which are spelling targets.
   3  */
   4 /* Copyright (C) 2005,2008,2009,2010,2011,2017 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_HONEY_SPELLINGWORDSLIST_H
  23 #define XAPIAN_INCLUDED_HONEY_SPELLINGWORDSLIST_H
  24
  25 #include "backends/alltermslist.h"
  26 #include "honey_spelling.h"
  27 #include "honey_cursor.h"
  28
  29 class HoneyDatabase;
  30
  31 class HoneySpellingWordsList : public AllTermsList {
  32     /// Copying is not allowed.
  33     HoneySpellingWordsList(const HoneySpellingWordsList &);
  34
  35     /// Assignment is not allowed.
  36     void operator=(const HoneySpellingWordsList &);
  37
  38     /// Keep a reference to our database to stop it being deleted.
  39     Xapian::Internal::intrusive_ptr<const HoneyDatabase> database;
  40
  41     /** A cursor which runs through the spelling table reading termnames from
  42      *  the keys.
  43      */
  44     HoneyCursor * 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     HoneySpellingWordsList(const HoneyDatabase* database_, HoneyCursor* cursor_)
  59             : database(database_), cursor(cursor_), termfreq(0) {
  60         // Set the cursor to its end to signal we haven't started yet.  Then
  61         // if the first action is next() it can use find_entry_ge("\x04") to
  62         // locate the first word.
  63         cursor->to_end();
  64     }
  65
  66     /// Destructor.
  67     ~HoneySpellingWordsList();
  68
  69     Xapian::termcount get_approx_size() const;
  70
  71     /** Returns the current termname.
  72      *
  73      *  Either next() or skip_to() must have been called before this
  74      *  method can be called.
  75      */
  76     std::string get_termname() const;
  77
  78     /** Returns the term frequency of the current term.
  79      *
  80      *  Either next() or skip_to() must have been called before this
  81      *  method can be called.
  82      */
  83     Xapian::doccount get_termfreq() const;
  84
  85     /** Returns the collection frequency of the current term.
  86      *
  87      *  Either next() or skip_to() must have been called before this
  88      *  method can be called.
  89      */
  90     Xapian::termcount get_collection_freq() const;
  91
  92     /// Advance to the next term in the list.
  93     TermList * next();
  94
  95     /// Advance to the first term which is >= term.
  96     TermList * skip_to(const std::string& term);
  97
  98     /// True if we're off the end of the list
  99     bool at_end() const;
 100 };
 101
 102 #endif /* XAPIAN_INCLUDED_HONEY_SPELLINGWORDSLIST_H */