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 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_wdf() const
  56 {
  57     Assert(did != 0);
  58     Assert(!at_end());
  59     return 1;
  60 }
  61
  62 PositionList *
  63 ContiguousAllDocsPostList::read_position_list()
  64 {
  65     // Throws the same exception.
  66     return ContiguousAllDocsPostList::open_position_list();
  67 }
  68
  69 PositionList *
  70 ContiguousAllDocsPostList::open_position_list() const
  71 {
  72     throw Xapian::InvalidOperationError("Position lists not meaningful for ContiguousAllDocsPostList");
  73 }
  74
  75 PostList *
  76 ContiguousAllDocsPostList::next(Xapian::weight)
  77 {
  78     Assert(!at_end());
  79     if (did == doccount) {
  80         db = NULL;
  81     } else {
  82         ++did;
  83     }
  84     return NULL;
  85 }
  86
  87 PostList *
  88 ContiguousAllDocsPostList::skip_to(Xapian::docid target, Xapian::weight)
  89 {
  90     Assert(!at_end());
  91     if (target > did) {
  92         if (target > doccount) {
  93             db = NULL;
  94         } else {
  95             did = target;
  96         }
  97     }
  98     return NULL;
  99 }
 100
 101 bool
 102 ContiguousAllDocsPostList::at_end() const
 103 {
 104     return db.get() == NULL;
 105 }
 106
 107 string
 108 ContiguousAllDocsPostList::get_description() const
 109 {
 110     string msg("ContiguousAllDocsPostList(1..");
 111     msg += str(doccount);
 112     msg += ')';
 113     return msg;
 114 }