xapian-core/include/xapian/registry.h

   1 /** @file
   2  * @brief Class for looking up user subclasses during unserialisation.
   3  */
   4 /* Copyright 2009 Lemur Consulting Ltd
   5  * Copyright 2009,2011,2013,2014 Olly Betts
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  20  * USA
  21  */
  22
  23 #ifndef XAPIAN_INCLUDED_REGISTRY_H
  24 #define XAPIAN_INCLUDED_REGISTRY_H
  25
  26 #if !defined XAPIAN_IN_XAPIAN_H && !defined XAPIAN_LIB_BUILD
  27 # error Never use <xapian/registry.h> directly; include <xapian.h> instead.
  28 #endif
  29
  30 #include <xapian/intrusive_ptr.h>
  31 #include <xapian/visibility.h>
  32 #include <string>
  33
  34 namespace Xapian {
  35
  36 // Forward declarations.
  37 class LatLongMetric;
  38 class MatchSpy;
  39 class PostingSource;
  40 class Weight;
  41
  42 /** Registry for user subclasses.
  43  *
  44  *  This class provides a way for the remote server to look up user subclasses
  45  *  when unserialising.
  46  */
  47 class XAPIAN_VISIBILITY_DEFAULT Registry {
  48   public:
  49     /// Class holding details of the registry.
  50     class Internal;
  51
  52   private:
  53     /// @internal Reference counted internals.
  54     Xapian::Internal::intrusive_ptr<Internal> internal;
  55
  56   public:
  57     /** Copy constructor.
  58      *
  59      *  The internals are reference counted, so copying is cheap.
  60      *
  61      *  @param other    The object to copy.
  62      */
  63     Registry(const Registry & other);
  64
  65     /** Assignment operator.
  66      *
  67      *  The internals are reference counted, so assignment is cheap.
  68      *
  69      *  @param other    The object to copy.
  70      */
  71     Registry & operator=(const Registry & other);
  72
  73 #ifdef XAPIAN_MOVE_SEMANTICS
  74     /** Move constructor.
  75      *
  76      * @param other     The object to move.
  77      */
  78     Registry(Registry && other);
  79
  80     /** Move assignment operator.
  81      *
  82      * @param other     The object to move.
  83      */
  84     Registry & operator=(Registry && other);
  85 #endif
  86
  87     /** Default constructor.
  88      *
  89      *  The registry will contain all standard subclasses of user-subclassable
  90      *  classes.
  91      */
  92     Registry();
  93
  94     ~Registry();
  95
  96     /** Register a weighting scheme.
  97      *
  98      *  @param wt       The weighting scheme to register.
  99      */
 100     void register_weighting_scheme(const Xapian::Weight &wt);
 101
 102     /** Get the weighting scheme given a name.
 103      *
 104      *  @param name     The name of the weighting scheme to find.
 105      *  @return         An object with the requested name, or NULL if the
 106      *                  weighting scheme could not be found.  The returned
 107      *                  object is owned by the registry and so must not be
 108      *                  deleted by the caller.
 109      */
 110     const Xapian::Weight *
 111             get_weighting_scheme(const std::string & name) const;
 112
 113     /** Register a user-defined posting source class.
 114      *
 115      *  @param source   The posting source to register.
 116      */
 117     void register_posting_source(const Xapian::PostingSource &source);
 118
 119     /** Get a posting source given a name.
 120      *
 121      *  @param name     The name of the posting source to find.
 122      *  @return         An object with the requested name, or NULL if the
 123      *                  posting source could not be found.  The returned
 124      *                  object is owned by the registry and so must not be
 125      *                  deleted by the caller.
 126      */
 127     const Xapian::PostingSource *
 128             get_posting_source(const std::string & name) const;
 129
 130     /** Register a user-defined match spy class.
 131      *
 132      *  @param spy      The match spy to register.
 133      */
 134     void register_match_spy(const Xapian::MatchSpy &spy);
 135
 136     /** Get a match spy given a name.
 137      *
 138      *  @param name     The name of the match spy to find.
 139      *  @return         An object with the requested name, or NULL if the
 140      *                  match spy could not be found.  The returned
 141      *                  object is owned by the registry and so must not be
 142      *                  deleted by the caller.
 143      */
 144     const Xapian::MatchSpy *
 145             get_match_spy(const std::string & name) const;
 146
 147     /// Register a user-defined lat-long metric class.
 148     void register_lat_long_metric(const Xapian::LatLongMetric &metric);
 149
 150     /** Get a lat-long metric given a name.
 151      *
 152      *  The returned metric is owned by the registry object.
 153      *
 154      *  Returns NULL if the metric could not be found.
 155      */
 156     const Xapian::LatLongMetric *
 157             get_lat_long_metric(const std::string & name) const;
 158
 159 };
 160
 161 }
 162
 163 #endif /* XAPIAN_INCLUDED_REGISTRY_H */