luabind/detail/class_registry.hpp

   1 // Copyright (c) 2003 Daniel Wallin and Arvid Norberg
   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
  24 #ifndef LUABIND_CLASS_REGISTRY_HPP_INCLUDED
  25 #define LUABIND_CLASS_REGISTRY_HPP_INCLUDED
  26
  27 #include <luabind/config.hpp>
  28 #include <luabind/open.hpp>
  29 #include <string>
  30
  31 namespace luabind { namespace detail
  32 {
  33         class class_rep;
  34
  35         struct class_registry
  36         {
  37                 class_registry(lua_State* L)
  38                         : m_cpp_instance_metatable(create_cpp_instance_metatable(L))
  39                         , m_cpp_class_metatable(create_cpp_class_metatable(L))
  40                         , m_lua_instance_metatable(create_lua_instance_metatable(L))
  41                         , m_lua_class_metatable(create_lua_class_metatable(L))
  42                         , m_lua_function_metatable(create_lua_function_metatable(L))
  43                 {}
  44
  45                 static inline class_registry* get_registry(lua_State* L)
  46                 {
  47
  48 #ifdef LUABIND_NOT_THREADSAFE
  49
  50                         // if we don't have to be thread safe, we can keep a
  51                         // chache of the class_registry pointer without the
  52                         // need of a mutex
  53                         static lua_State* cache_key = 0;
  54                         static class_registry* registry_cache = 0;
  55                         if (cache_key == L) return registry_cache;
  56
  57 #endif
  58
  59                         lua_pushstring(L, "__luabind_classes");
  60                         lua_gettable(L, LUA_REGISTRYINDEX);
  61                         class_registry* p = static_cast<class_registry*>(lua_touserdata(L, -1));
  62                         lua_pop(L, 1);
  63
  64 #ifdef LUABIND_NOT_THREADSAFE
  65
  66                         cache_key = L;
  67                         registry_cache = p;
  68
  69 #endif
  70
  71                         return p;
  72                 }
  73
  74                 int cpp_instance() const { return m_cpp_instance_metatable; }
  75                 int cpp_class() const { return m_cpp_class_metatable; }
  76
  77                 int lua_instance() const { return m_lua_instance_metatable; }
  78                 int lua_class() const { return m_lua_class_metatable; }
  79                 int lua_function() const { return m_lua_function_metatable; }
  80
  81                 void add_class(LUABIND_TYPE_INFO info, class_rep* crep)
  82                 {
  83                         // class is already registered
  84                         assert((m_classes.find(info) == m_classes.end()) && "you are trying to register a class twice");
  85                         m_classes[info] = crep;
  86                 }
  87
  88                 struct cmp
  89                 {
  90                         bool operator()(const std::type_info* a, const std::type_info* b) const
  91                         {
  92                                 return a->before(*b) != 0;
  93                         }
  94
  95                         template<class T>
  96                         bool operator()(const T& a, const T& b) const
  97                         {
  98                                 return a < b;
  99                         }
 100                 };
 101
 102                 class_rep* find_class(LUABIND_TYPE_INFO info)
 103                 {
 104                         std::map<LUABIND_TYPE_INFO, class_rep*, cmp>::iterator i = m_classes.find(info);
 105                         if (i == m_classes.end()) return 0; // the type is not registered
 106                         return i->second;
 107                 }
 108
 109         private:
 110
 111                 std::map<LUABIND_TYPE_INFO, class_rep*, cmp> m_classes;
 112
 113                 // this is a lua reference that points to the lua table
 114                 // that is to be used as meta table for all C++ class
 115                 // instances. It is a kind of v-table.
 116                 int m_cpp_instance_metatable;
 117
 118                 // this is a lua reference to the metatable to be used
 119                 // for all classes defined in C++.
 120                 int m_cpp_class_metatable;
 121
 122                 // this is a lua reference that points to the lua table
 123                 // that is to be used as meta table for all lua class
 124                 // instances. It is a kind of v-table.
 125                 int m_lua_instance_metatable;
 126
 127                 // this is a lua reference to the metatable to be used
 128                 // for all classes defined in lua
 129                 int m_lua_class_metatable;
 130
 131                 // this metatable only contains a destructor
 132                 // for luabind::Detail::free_functions::function_rep
 133                 int m_lua_function_metatable;
 134
 135         };
 136
 137 }}
 138
 139 #endif // LUABIND_CLASS_REGISTRY_HPP_INCLUDED
 140