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                 void set_instance(instance_holder* instance) { m_instance = instance; }
  54
  55                 void add_dependency(lua_State* L, int index);
  56         void release_dependency_refs(lua_State* L);
  57
  58                 std::pair<void*, int> get_instance(type_id const& target) const
  59                 {
  60                         if (m_instance == 0)
  61                                 return std::pair<void*, int>(0, -1);
  62                         return m_instance->get(target);
  63                 }
  64
  65                 bool is_const() const
  66                 {
  67                         return m_instance && m_instance->pointee_const();
  68                 }
  69
  70         void release()
  71         {
  72             if (m_instance)
  73                 m_instance->release();
  74         }
  75
  76                 void* allocate(std::size_t size)
  77                 {
  78                         if (size <= 32)
  79                                 return &m_instance_buffer;
  80                         return std::malloc(size);
  81                 }
  82
  83                 void deallocate(void* storage)
  84                 {
  85                         if (storage == &m_instance_buffer)
  86                                 return;
  87                         std::free(storage);
  88                 }
  89
  90         private:
  91         instance_holder* m_instance;
  92         boost::aligned_storage<32> m_instance_buffer;
  93                 class_rep* m_classrep; // the class information about this object's type
  94                 int m_dependency_cnt; // counts dependencies
  95         };
  96
  97         template<class T>
  98         struct delete_s
  99         {
 100                 static void apply(void* ptr)
 101                 {
 102                         delete static_cast<T*>(ptr);
 103                 }
 104         };
 105
 106         template<class T>
 107         struct destruct_only_s
 108         {
 109                 static void apply(void* ptr)
 110                 {
 111                         // Removes unreferenced formal parameter warning on VC7.
 112                         (void)ptr;
 113 #ifndef NDEBUG
 114                         int completeness_check[sizeof(T)];
 115                         (void)completeness_check;
 116 #endif
 117                         static_cast<T*>(ptr)->~T();
 118                 }
 119         };
 120
 121
 122         inline object_rep* is_class_object(lua_State* L, int index)
 123         {
 124                 object_rep* obj = static_cast<detail::object_rep*>(lua_touserdata(L, index));
 125                 if (!obj) return 0;
 126                 if (lua_getmetatable(L, index) == 0) return 0;
 127
 128                 lua_pushstring(L, "__luabind_class");
 129                 lua_gettable(L, -2);
 130                 bool confirmation = lua_toboolean(L, -1) != 0;
 131                 lua_pop(L, 2);
 132                 if (!confirmation) return 0;
 133                 return obj;
 134
 135         }
 136
 137     LUABIND_API object_rep* get_instance(lua_State* L, int index);
 138     LUABIND_API void push_instance_metatable(lua_State* L);
 139     LUABIND_API object_rep* push_new_instance(lua_State* L, class_rep* cls);
 140
 141 }}
 142
 143 #endif // LUABIND_OBJECT_REP_HPP_INCLUDED
 144