src/class_registry.cpp

   1 // Copyright (c) 2004 Daniel Wallin
   2
   3 // Permission is hereby granted, free of charge, to any person obtaining a
   4 // copy of this software and associated documentation files (the "Software"),
   5 // to deal in the Software without restriction, including without limitation
   6 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7 // and/or sell copies of the Software, and to permit persons to whom the
   8 // Software is furnished to do so, subject to the following conditions:
   9
  10 // The above copyright notice and this permission notice shall be included
  11 // in all copies or substantial portions of the Software.
  12
  13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
  14 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
  15 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  16 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
  17 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  18 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  19 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
  21 // OR OTHER DEALINGS IN THE SOFTWARE.
  22
  23 #define LUABIND_BUILDING
  24
  25 #include <luabind/lua_include.hpp>
  26
  27 #include <luabind/luabind.hpp>
  28 #include <luabind/detail/class_registry.hpp>
  29 #include <luabind/detail/class_rep.hpp>
  30 #include <luabind/detail/operator_id.hpp>
  31
  32 namespace luabind { namespace detail {
  33
  34     LUABIND_API void push_instance_metatable(lua_State* L);
  35
  36     namespace {
  37
  38         int create_cpp_class_metatable(lua_State* L)
  39         {
  40             lua_newtable(L);
  41
  42             // mark the table with our (hopefully) unique tag
  43             // that says that the user data that has this
  44             // metatable is a class_rep
  45             lua_pushstring(L, "__luabind_classrep");
  46             lua_pushboolean(L, 1);
  47             lua_rawset(L, -3);
  48
  49             lua_pushstring(L, "__gc");
  50             lua_pushcclosure(
  51                 L
  52               , &garbage_collector_s<
  53                     detail::class_rep
  54                 >::apply
  55                 , 0);
  56
  57             lua_rawset(L, -3);
  58
  59             lua_pushstring(L, "__call");
  60             lua_pushcclosure(L, &class_rep::constructor_dispatcher, 0);
  61             lua_rawset(L, -3);
  62
  63             lua_pushstring(L, "__index");
  64             lua_pushcclosure(L, &class_rep::static_class_gettable, 0);
  65             lua_rawset(L, -3);
  66
  67             lua_pushstring(L, "__newindex");
  68             lua_pushcclosure(L, &class_rep::lua_settable_dispatcher, 0);
  69             lua_rawset(L, -3);
  70
  71             return luaL_ref(L, LUA_REGISTRYINDEX);
  72         }
  73
  74         int create_lua_class_metatable(lua_State* L)
  75         {
  76             lua_newtable(L);
  77
  78             lua_pushstring(L, "__luabind_classrep");
  79             lua_pushboolean(L, 1);
  80             lua_rawset(L, -3);
  81
  82             lua_pushstring(L, "__gc");
  83             lua_pushcclosure(
  84                 L
  85               , &detail::garbage_collector_s<
  86                     detail::class_rep
  87                 >::apply
  88                 , 0);
  89
  90             lua_rawset(L, -3);
  91
  92             lua_pushstring(L, "__newindex");
  93             lua_pushcclosure(L, &class_rep::lua_settable_dispatcher, 0);
  94             lua_rawset(L, -3);
  95
  96             lua_pushstring(L, "__call");
  97             lua_pushcclosure(L, &class_rep::constructor_dispatcher, 0);
  98             lua_rawset(L, -3);
  99
 100             lua_pushstring(L, "__index");
 101             lua_pushcclosure(L, &class_rep::static_class_gettable, 0);
 102             lua_rawset(L, -3);
 103
 104             return luaL_ref(L, LUA_REGISTRYINDEX);
 105         }
 106
 107     } // namespace unnamed
 108
 109     class class_rep;
 110
 111     class_registry::class_registry(lua_State* L)
 112         : m_cpp_class_metatable(create_cpp_class_metatable(L))
 113         , m_lua_class_metatable(create_lua_class_metatable(L))
 114     {
 115         push_instance_metatable(L);
 116         m_instance_metatable = luaL_ref(L, LUA_REGISTRYINDEX);
 117     }
 118
 119     class_registry* class_registry::get_registry(lua_State* L)
 120     {
 121
 122 #ifdef LUABIND_NOT_THREADSAFE
 123
 124         // if we don't have to be thread safe, we can keep a
 125         // chache of the class_registry pointer without the
 126         // need of a mutex
 127         static lua_State* cache_key = 0;
 128         static class_registry* registry_cache = 0;
 129         if (cache_key == L) return registry_cache;
 130
 131 #endif
 132
 133         lua_pushstring(L, "__luabind_classes");
 134         lua_gettable(L, LUA_REGISTRYINDEX);
 135         class_registry* p = static_cast<class_registry*>(lua_touserdata(L, -1));
 136         lua_pop(L, 1);
 137
 138 #ifdef LUABIND_NOT_THREADSAFE
 139
 140         cache_key = L;
 141         registry_cache = p;
 142
 143 #endif
 144
 145         return p;
 146     }
 147
 148     void class_registry::add_class(type_id const& info, class_rep* crep)
 149     {
 150         // class is already registered
 151         assert((m_classes.find(info) == m_classes.end())
 152             && "you are trying to register a class twice");
 153         m_classes[info] = crep;
 154     }
 155
 156     class_rep* class_registry::find_class(type_id const& info) const
 157     {
 158         std::map<type_id, class_rep*>::const_iterator i(
 159             m_classes.find(info));
 160
 161         if (i == m_classes.end()) return 0; // the type is not registered
 162         return i->second;
 163     }
 164
 165 }} // namespace luabind::detail
 166