src/filter_factory.hpp

   1 /* $Id: filter_factory.hpp,v 1.3 2005-10-29 22:51:11 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             FilterFactory(){};
  40
  41             bool add_creator(std::string fi, CreateFilterCallback cfc);
  42             /// true if unregistration ok
  43
  44             bool drop_creator(std::string fi);
  45
  46             /// factory create method
  47
  48             yp2::filter::Base* create(std::string fi);
  49
  50         private:
  51             typedef std::map<std::string, CreateFilterCallback> CallbackMap;
  52             CallbackMap m_fcm;
  53
  54         private:
  55             /// disabled because class is singleton
  56             FilterFactory(const FilterFactory &);
  57
  58             /// disabled because class is singleton
  59             FilterFactory& operator=(const FilterFactory &);
  60         };
  61
  62     }
  63
  64     bool yp2::filter::FilterFactory::add_creator(std::string fi,
  65                                     CreateFilterCallback cfc)
  66     {
  67         return m_fcm.insert(CallbackMap::value_type(fi, cfc)).second;
  68     }
  69
  70
  71     bool yp2::filter::FilterFactory::drop_creator(std::string fi)
  72     {
  73         return m_fcm.erase(fi) == 1;
  74     }
  75
  76     yp2::filter::Base* yp2::filter::FilterFactory::create(std::string fi)
  77     {
  78         CallbackMap::const_iterator i = m_fcm.find(fi);
  79
  80         if (i == m_fcm.end()){
  81             std::string msg = "filter type '" + fi + "' not found";
  82             throw yp2::filter::FilterFactoryException(msg);
  83         }
  84         // call create function
  85         return (i->second());
  86     }
  87
  88
  89
  90 }
  91
  92 #endif
  93 /*
  94  * Local variables:
  95  * c-basic-offset: 4
  96  * indent-tabs-mode: nil
  97  * c-file-style: "stroustrup"
  98  * End:
  99  * vim: shiftwidth=4 tabstop=8 expandtab
 100  */