xapian-core/backends/valuestats.h

   1 /** @file valuestats.h
   2  * @brief Statistics about values.
   3  */
   4 /* Copyright 2008 Lemur Consulting Ltd
   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
  19  * USA
  20  */
  21
  22 #ifndef XAPIAN_INCLUDED_VALUESTATS_H
  23 #define XAPIAN_INCLUDED_VALUESTATS_H
  24
  25 #include <string>
  26 #include "xapian/types.h"
  27
  28 /** Class to hold statistics for a given slot. */
  29 struct ValueStats {
  30     /** The number of documents which have a (non-empty) value stored in the
  31      *  slot.
  32      */
  33     Xapian::doccount freq;
  34
  35     /** A lower bound on the values stored in the given value slot.
  36      */
  37     std::string lower_bound;
  38
  39     /** An upper bound on the values stored in the given value slot.
  40      */
  41     std::string upper_bound;
  42
  43     /// Construct an empty ValueStats object.
  44     ValueStats() : freq(0), lower_bound(), upper_bound() {}
  45
  46     /** Clear the statistics.
  47      */
  48     void clear() {
  49         freq = 0;
  50         lower_bound.resize(0);
  51         upper_bound.resize(0);
  52     }
  53 };
  54
  55 #endif /* XAPIAN_INCLUDED_VALUESTATS_H */