src/filter_factory.hpp

   1 /* $Id: filter_factory.hpp,v 1.4 2005-10-31 09:40:18 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     class FilterFactoryException : public std::runtime_error {
  24     public:
  25         FilterFactoryException(const std::string message)
  26             : std::runtime_error("FilterException: " + message){
  27         };
  28     };
  29
  30         class FilterFactory {
  31
  32         public:
  33             typedef yp2::filter::Base* (*CreateFilterCallback)();
  34             /// true if registration ok
  35
  36             FilterFactory(){};
  37
  38             bool add_creator(std::string fi, CreateFilterCallback cfc);
  39             /// true if unregistration ok
  40
  41             bool drop_creator(std::string fi);
  42
  43             /// factory create method
  44
  45             yp2::filter::Base* create(std::string fi);
  46
  47         private:
  48             typedef std::map<std::string, CreateFilterCallback> CallbackMap;
  49             CallbackMap m_fcm;
  50
  51         private:
  52             /// disabled because class is singleton
  53             FilterFactory(const FilterFactory &);
  54
  55             /// disabled because class is singleton
  56             FilterFactory& operator=(const FilterFactory &);
  57         };
  58
  59     }
  60
  61     bool yp2::filter::FilterFactory::add_creator(std::string fi,
  62                                     CreateFilterCallback cfc)
  63     {
  64         return m_fcm.insert(CallbackMap::value_type(fi, cfc)).second;
  65     }
  66
  67
  68     bool yp2::filter::FilterFactory::drop_creator(std::string fi)
  69     {
  70         return m_fcm.erase(fi) == 1;
  71     }
  72
  73     yp2::filter::Base* yp2::filter::FilterFactory::create(std::string fi)
  74     {
  75         CallbackMap::const_iterator i = m_fcm.find(fi);
  76
  77         if (i == m_fcm.end()){
  78             std::string msg = "filter type '" + fi + "' not found";
  79             throw yp2::filter::FilterFactoryException(msg);
  80         }
  81         // call create function
  82         return (i->second());
  83     }
  84
  85
  86
  87 }
  88
  89 #endif
  90 /*
  91  * Local variables:
  92  * c-basic-offset: 4
  93  * indent-tabs-mode: nil
  94  * c-file-style: "stroustrup"
  95  * End:
  96  * vim: shiftwidth=4 tabstop=8 expandtab
  97  */