src/filter_factory.hpp

   1 /* $Id: filter_factory.hpp,v 1.2 2005-10-29 17:58:14 marc Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7 #ifndef FILTER_FACTORY_HPP
   8 #define FILTER_FACTORY_HPP
   9
  10 #include <stdexcept>
  11 #include <iostream>
  12 #include <string>
  13 #include <map>
  14
  15 #include "config.hpp"
  16 #include "filter.hpp"
  17
  18
  19 namespace yp2 {
  20
  21     namespace filter {
  22
  23
  24
  25
  26     class FilterFactoryException : public std::runtime_error {
  27     public:
  28         FilterFactoryException(const std::string message)
  29             : std::runtime_error("FilterException: " + message){
  30         };
  31     };
  32
  33         class FilterFactory {
  34
  35         public:
  36             typedef yp2::filter::Base* (*CreateFilterCallback)();
  37             /// true if registration ok
  38
  39             bool add_creator(std::string fi, CreateFilterCallback cfc);
  40             /// true if unregistration ok
  41
  42             bool drop_creator(std::string fi);
  43
  44             /// factory create method
  45
  46             yp2::filter::Base* create(std::string fi);
  47
  48         private:
  49             typedef std::map<std::string, CreateFilterCallback> CallbackMap;
  50             CallbackMap m_fcm;
  51
  52         };
  53
  54     }
  55
  56     bool yp2::filter::FilterFactory::add_creator(std::string fi,
  57                                     CreateFilterCallback cfc)
  58     {
  59         return m_fcm.insert(CallbackMap::value_type(fi, cfc)).second;
  60     }
  61
  62
  63     bool yp2::filter::FilterFactory::drop_creator(std::string fi)
  64     {
  65         return m_fcm.erase(fi) == 1;
  66     }
  67
  68     yp2::filter::Base* yp2::filter::FilterFactory::create(std::string fi)
  69     {
  70         CallbackMap::const_iterator i = m_fcm.find(fi);
  71
  72         if (i == m_fcm.end()){
  73             std::string msg = "filter type '" + fi + "' not found";
  74             throw yp2::filter::FilterFactoryException(msg);
  75         }
  76         // call create function
  77         return (i->second());
  78     }
  79
  80
  81
  82 }
  83
  84 #endif
  85 /*
  86  * Local variables:
  87  * c-basic-offset: 4
  88  * indent-tabs-mode: nil
  89  * c-file-style: "stroustrup"
  90  * End:
  91  * vim: shiftwidth=4 tabstop=8 expandtab
  92  */