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