luabind/detail/object_rep.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_OBJECT_REP_HPP_INCLUDED
  25 #define LUABIND_OBJECT_REP_HPP_INCLUDED
  26
  27 #include <boost/aligned_storage.hpp>
  28 #include <luabind/config.hpp>
  29 #include <luabind/detail/instance_holder.hpp>
  30 #include <luabind/detail/ref.hpp>
  31
  32 namespace luabind { namespace detail
  33 {
  34         class class_rep;
  35
  36         void finalize(lua_State* L, class_rep* crep);
  37
  38         // this class is allocated inside lua for each pointer.
  39         // it contains the actual c++ object-pointer.
  40         // it also tells if it is const or not.
  41         class LUABIND_API object_rep
  42         {
  43         public:
  44                 enum { constant = 1, owner = 2, lua_class = 4, call_super = 8 };
  45
  46                 // dest is a function that is called to delete the c++ object this struct holds
  47                 object_rep(instance_holder* instance, class_rep* crep);
  48                 ~object_rep();
  49
  50                 const class_rep* crep() const { return m_classrep; }
  51                 class_rep* crep() { return m_classrep; }
  52
  53                 detail::lua_reference& get_lua_table() { return m_lua_table_ref; }
  54                 detail::lua_reference const& get_lua_table() const { return m_lua_table_ref; }
  55
  56                 void set_instance(instance_holder* instance) { m_instance = instance; }
  57
  58                 void add_dependency(lua_State* L, int index);
  59
  60                 std::pair<void*, int> get_instance(class_id target) const
  61                 {
  62                         if (m_instance == 0)
  63                                 return std::pair<void*, int>(0, -1);
  64                         return m_instance->get(target);
  65                 }
  66
  67                 bool is_const() const
  68                 {
  69                         return m_instance && m_instance->pointee_const();
  70                 }
  71
  72         void release()
  73         {
  74             if (m_instance)
  75                 m_instance->release();
  76         }
  77
  78                 void* allocate(std::size_t size)
  79                 {
  80                         if (size <= 32)
  81                                 return &m_instance_buffer;
  82                         return std::malloc(size);
  83                 }
  84
  85                 void deallocate(void* storage)
  86                 {
  87                         if (storage == &m_instance_buffer)
  88                                 return;
  89                         std::free(storage);
  90                 }
  91
  92         private:
  93         instance_holder* m_instance;
  94         boost::aligned_storage<32> m_instance_buffer;
  95                 class_rep* m_classrep; // the class information about this object's type
  96                 detail::lua_reference m_lua_table_ref; // reference to lua table if this is a lua class
  97                 int m_dependency_cnt; // counts dependencies
  98                 detail::lua_reference m_dependency_ref; // reference to lua table holding dependency references
  99         };
 100
 101         template<class T>
 102         struct delete_s
 103         {
 104                 static void apply(void* ptr)
 105                 {
 106                         delete static_cast<T*>(ptr);
 107                 }
 108         };
 109
 110         template<class T>
 111         struct destruct_only_s
 112         {
 113                 static void apply(void* ptr)
 114                 {
 115                         // Removes unreferenced formal parameter warning on VC7.
 116                         (void)ptr;
 117 #ifndef NDEBUG
 118                         int completeness_check[sizeof(T)];
 119                         (void)completeness_check;
 120 #endif
 121                         static_cast<T*>(ptr)->~T();
 122                 }
 123         };
 124
 125
 126         inline object_rep* is_class_object(lua_State* L, int index)
 127         {
 128                 object_rep* obj = static_cast<detail::object_rep*>(lua_touserdata(L, index));
 129                 if (!obj) return 0;
 130                 if (lua_getmetatable(L, index) == 0) return 0;
 131
 132                 lua_pushstring(L, "__luabind_class");
 133                 lua_gettable(L, -2);
 134                 bool confirmation = lua_toboolean(L, -1) != 0;
 135                 lua_pop(L, 2);
 136                 if (!confirmation) return 0;
 137                 return obj;
 138
 139         }
 140
 141     LUABIND_API object_rep* get_instance(lua_State* L, int index);
 142     LUABIND_API void push_instance_metatable(lua_State* L);
 143     LUABIND_API object_rep* push_new_instance(lua_State* L, class_rep* cls);
 144
 145 }}
 146
 147 #endif // LUABIND_OBJECT_REP_HPP_INCLUDED
 148