xapian-core/api/maptermlist.h

   1 /** @file maptermlist.h
   2  * @brief TermList which iterates a std::map.
   3  */
   4 /* Copyright 1999,2000,2001 BrightStation PLC
   5  * Copyright 2002,2003,2004,2005,2006,2007,2008,2010,2011,2013 Olly Betts
   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
  20  * USA
  21  */
  22
  23 #ifndef OM_HGUARD_MAPTERMLIST_H
  24 #define OM_HGUARD_MAPTERMLIST_H
  25
  26 #include "termlist.h"
  27
  28 #include "backends/inmemory/inmemory_positionlist.h"
  29 #include "backends/document.h"
  30
  31 #include "omassert.h"
  32
  33 using namespace std;
  34
  35 class MapTermList : public TermList {
  36     private:
  37         Xapian::Document::Internal::document_terms::const_iterator it;
  38         Xapian::Document::Internal::document_terms::const_iterator it_end;
  39         bool started;
  40
  41     public:
  42         MapTermList(const Xapian::Document::Internal::document_terms::const_iterator &it_,
  43                     const Xapian::Document::Internal::document_terms::const_iterator &it_end_)
  44                 : it(it_), it_end(it_end_), started(false)
  45         { }
  46
  47         // Gets size of termlist
  48         Xapian::termcount get_approx_size() const {
  49             // This method shouldn't get called on a MapTermList.
  50             Assert(false);
  51             return 0;
  52         }
  53
  54         // Gets current termname
  55         string get_termname() const {
  56             Assert(started);
  57             Assert(!at_end());
  58             return it->first;
  59         }
  60
  61         // Get wdf of current term
  62         Xapian::termcount get_wdf() const {
  63             Assert(started);
  64             Assert(!at_end());
  65             return it->second.wdf;
  66         }
  67
  68         // Get num of docs indexed by term
  69         Xapian::doccount get_termfreq() const {
  70             throw Xapian::InvalidOperationError("Can't get term frequency from a document termlist which is not associated with a database.");
  71         }
  72
  73         const std::vector<Xapian::termpos> * get_vector_termpos() const {
  74             return it->second.get_vector_termpos();
  75         }
  76
  77         Xapian::PositionIterator positionlist_begin() const {
  78             auto p = it->second.get_vector_termpos();
  79             return Xapian::PositionIterator(new InMemoryPositionList(*p));
  80         }
  81
  82         Xapian::termcount positionlist_count() const {
  83             return it->second.positionlist_count();
  84         }
  85
  86         TermList * next() {
  87             if (!started) {
  88                 started = true;
  89             } else {
  90                 Assert(!at_end());
  91                 ++it;
  92             }
  93             while (it != it_end && it->second.is_deleted()) {
  94                 ++it;
  95             }
  96             return NULL;
  97         }
  98
  99         TermList * skip_to(const std::string & term) {
 100             while (it != it_end && it->first < term) {
 101                 ++it;
 102             }
 103             started = true;
 104             while (it != it_end && it->second.is_deleted()) {
 105                 ++it;
 106             }
 107             return NULL;
 108         }
 109
 110         // True if we're off the end of the list
 111         bool at_end() const {
 112             Assert(started);
 113             return it == it_end;
 114         }
 115 };
 116
 117 #endif /* OM_HGUARD_MAPTERMLIST_H */