xapian-core/backends/slowvaluelist.h

   1 /** @file slowvaluelist.h
   2  * @brief Slow implementation for backends which don't streamed values.
   3  */
   4 /* Copyright (C) 2007,2008,2011,2014 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 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_SLOWVALUELIST_H
  22 #define XAPIAN_INCLUDED_SLOWVALUELIST_H
  23
  24 #include "valuelist.h"
  25
  26 #include "database.h"
  27
  28 /** Slow implementation for backends which don't streamed values.
  29  *
  30  *  Used by inmemory and remote backends.
  31  */
  32 class SlowValueList : public ValueList {
  33     /// Don't allow assignment.
  34     void operator=(const SlowValueList &);
  35
  36     /// Don't allow copying.
  37     SlowValueList(const SlowValueList &);
  38
  39     /// The subdatabase.
  40     Xapian::Internal::intrusive_ptr<const Xapian::Database::Internal> db;
  41
  42     /// The last docid in the database, or 0 if we're at_end.
  43     Xapian::docid last_docid;
  44
  45     /// The value slot we're iterating over.
  46     Xapian::valueno slot;
  47
  48     /// The value at the current position.
  49     std::string current_value;
  50
  51     /// The document id at the current position.
  52     Xapian::docid current_did;
  53
  54   public:
  55     SlowValueList(const Xapian::Database::Internal * db_, Xapian::valueno slot_)
  56         : db(db_), last_docid(db_->get_lastdocid()), slot(slot_), current_did(0)
  57     { }
  58
  59     Xapian::docid get_docid() const;
  60
  61     std::string get_value() const;
  62
  63     Xapian::valueno get_valueno() const;
  64
  65     bool at_end() const;
  66
  67     void next();
  68
  69     void skip_to(Xapian::docid);
  70
  71     bool check(Xapian::docid did);
  72
  73     std::string get_description() const;
  74 };
  75
  76 #endif // XAPIAN_INCLUDED_SLOWVALUELIST_H