xapian-core/matcher/msetpostlist.h

   1 /** @file msetpostlist.h
   2  *  @brief PostList returning entries from an MSet
   3  */
   4 /* Copyright (C) 2006,2007,2008,2009,2011,2015 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 #ifndef XAPIAN_INCLUDED_MSETPOSTLIST_H
  22 #define XAPIAN_INCLUDED_MSETPOSTLIST_H
  23
  24 #include "xapian/enquire.h"
  25
  26 #include "api/omenquireinternal.h"
  27 #include "api/postlist.h"
  28
  29 /** PostList returning entries from an MSet.
  30  *
  31  *  This class is used with the remote backend.  We perform a match on the
  32  *  remote server, then serialise the resulting MSet and pass it back to the
  33  *  client where we include it in the match by wrapping it in an MSetPostList.
  34  */
  35 class MSetPostList : public PostList {
  36     /// Don't allow assignment.
  37     void operator=(const MSetPostList &);
  38
  39     /// Don't allow copying.
  40     MSetPostList(const MSetPostList &);
  41
  42     /// The MSet element that this PostList is pointing to.
  43     int cursor;
  44
  45     /// The MSet::Internal object which we're returning entries from.
  46     Xapian::Internal::intrusive_ptr<Xapian::MSet::Internal> mset_internal;
  47
  48     /** Is the sort order such the relevance decreases down the MSet?
  49      *
  50      *  This is true for sort_by_relevance and sort_by_relevance_then_value.
  51      */
  52     bool decreasing_relevance;
  53
  54   public:
  55     MSetPostList(const Xapian::MSet mset, bool decreasing_relevance_)
  56         : cursor(-1), mset_internal(mset.internal),
  57           decreasing_relevance(decreasing_relevance_) { }
  58
  59     Xapian::doccount get_termfreq_min() const;
  60
  61     Xapian::doccount get_termfreq_est() const;
  62
  63     Xapian::doccount get_termfreq_max() const;
  64
  65     double get_maxweight() const;
  66
  67     Xapian::docid get_docid() const;
  68
  69     double get_weight() const;
  70
  71     const std::string * get_sort_key() const;
  72
  73     const std::string * get_collapse_key() const;
  74
  75     /// Not implemented for MSetPostList.
  76     Xapian::termcount get_doclength() const;
  77
  78     Xapian::termcount get_unique_terms() const;
  79
  80     double recalc_maxweight();
  81
  82     PostList *next(double w_min);
  83
  84     /// Not meaningful for MSetPostList.
  85     PostList *skip_to(Xapian::docid did, double w_min);
  86
  87     bool at_end() const;
  88
  89     std::string get_description() const;
  90 };
  91
  92 #endif /* XAPIAN_INCLUDED_MSETPOSTLIST_H */