xapian-core/api/maptermlist.h

   1 /* maptermlist.h
   2  *
   3  * Copyright 1999,2000,2001 BrightStation PLC
   4  * Copyright 2002,2003,2004,2005,2006,2007,2008,2010 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  19  * USA
  20  */
  21
  22 #ifndef OM_HGUARD_MAPTERMLIST_H
  23 #define OM_HGUARD_MAPTERMLIST_H
  24
  25 #include "termlist.h"
  26
  27 #include "inmemory_positionlist.h"
  28 #include "document.h"
  29
  30 #include "omassert.h"
  31
  32 using namespace std;
  33
  34 class MapTermList : public TermList {
  35     private:
  36         Xapian::Document::Internal::document_terms::const_iterator it;
  37         Xapian::Document::Internal::document_terms::const_iterator it_end;
  38         bool started;
  39
  40     public:
  41         MapTermList(const Xapian::Document::Internal::document_terms::const_iterator &it_,
  42                     const Xapian::Document::Internal::document_terms::const_iterator &it_end_)
  43                 : it(it_), it_end(it_end_), started(false)
  44         { }
  45
  46         // Gets size of termlist
  47         Xapian::termcount get_approx_size() const {
  48             // This method shouldn't get called on a MapTermList.
  49             Assert(false);
  50             return 0;
  51         }
  52
  53         // Gets current termname
  54         string get_termname() const {
  55             Assert(started);
  56             Assert(!at_end());
  57             return it->first;
  58         }
  59
  60         // Get wdf of current term
  61         Xapian::termcount get_wdf() const {
  62             Assert(started);
  63             Assert(!at_end());
  64             return it->second.wdf;
  65         }
  66
  67         // Get num of docs indexed by term
  68         Xapian::doccount get_termfreq() const {
  69             throw Xapian::InvalidOperationError("Can't get term frequency from a document termlist which is not associated with a database.");
  70         }
  71
  72         Xapian::PositionIterator positionlist_begin() const {
  73             return Xapian::PositionIterator(new InMemoryPositionList(it->second.positions));
  74         }
  75
  76         Xapian::termcount positionlist_count() const {
  77             return it->second.positions.size();
  78         }
  79
  80         TermList * next() {
  81             if (!started) {
  82                 started = true;
  83             } else {
  84                 Assert(!at_end());
  85                 ++it;
  86             }
  87             return NULL;
  88         }
  89
  90         TermList * skip_to(const std::string & term) {
  91             while (it != it_end && it->first < term) {
  92                 ++it;
  93             }
  94             started = true;
  95             return NULL;
  96         }
  97
  98         // True if we're off the end of the list
  99         bool at_end() const {
 100             Assert(started);
 101             return it == it_end;
 102         }
 103 };
 104
 105 #endif /* OM_HGUARD_MAPTERMLIST_H */