xapian-core/backends/contiguousalldocspostlist.cc

   1 /** @file contiguousalldocspostlist.cc
   2  * @brief Iterate all document ids when they form a contiguous range.
   3  */
   4 /* Copyright (C) 2007,2008,2009,2011 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (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 USA
  19  */
  20
  21 #include <config.h>
  22
  23 #include <string>
  24
  25 #include "contiguousalldocspostlist.h"
  26
  27 #include "omassert.h"
  28 #include "str.h"
  29
  30 using namespace std;
  31
  32 Xapian::doccount
  33 ContiguousAllDocsPostList::get_termfreq() const
  34 {
  35     return doccount;
  36 }
  37
  38 Xapian::docid
  39 ContiguousAllDocsPostList::get_docid() const
  40 {
  41     Assert(did != 0);
  42     Assert(!at_end());
  43     return did;
  44 }
  45
  46 Xapian::termcount
  47 ContiguousAllDocsPostList::get_doclength() const
  48 {
  49     Assert(did != 0);
  50     Assert(!at_end());
  51     return db->get_doclength(did);
  52 }
  53
  54 Xapian::termcount
  55 ContiguousAllDocsPostList::get_unique_terms() const
  56 {
  57     Assert(did != 0);
  58     Assert(!at_end());
  59     return db->get_unique_terms(did);
  60 }
  61
  62 Xapian::termcount
  63 ContiguousAllDocsPostList::get_wdf() const
  64 {
  65     Assert(did != 0);
  66     Assert(!at_end());
  67     return 1;
  68 }
  69
  70 PositionList *
  71 ContiguousAllDocsPostList::read_position_list()
  72 {
  73     // Throws the same exception.
  74     return ContiguousAllDocsPostList::open_position_list();
  75 }
  76
  77 PositionList *
  78 ContiguousAllDocsPostList::open_position_list() const
  79 {
  80     throw Xapian::InvalidOperationError("Position lists not meaningful for ContiguousAllDocsPostList");
  81 }
  82
  83 PostList *
  84 ContiguousAllDocsPostList::next(double)
  85 {
  86     Assert(!at_end());
  87     if (did == doccount) {
  88         db = NULL;
  89     } else {
  90         ++did;
  91     }
  92     return NULL;
  93 }
  94
  95 PostList *
  96 ContiguousAllDocsPostList::skip_to(Xapian::docid target, double)
  97 {
  98     Assert(!at_end());
  99     if (target > did) {
 100         if (target > doccount) {
 101             db = NULL;
 102         } else {
 103             did = target;
 104         }
 105     }
 106     return NULL;
 107 }
 108
 109 bool
 110 ContiguousAllDocsPostList::at_end() const
 111 {
 112     return db.get() == NULL;
 113 }
 114
 115 string
 116 ContiguousAllDocsPostList::get_description() const
 117 {
 118     string msg("ContiguousAllDocsPostList(1..");
 119     msg += str(doccount);
 120     msg += ')';
 121     return msg;
 122 }