common/luaobject.h

   1 /*
   2  * luaobject.h - useful functions for handling Lua objects
   3  *
   4  * Copyright © 2009 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #ifndef AWESOME_COMMON_LUAOBJECT
  23 #define AWESOME_COMMON_LUAOBJECT
  24
  25 #include <lauxlib.h>
  26 #include "common/array.h"
  27
  28 /** Type for Lua references */
  29 typedef int luaA_ref;
  30
  31 static inline int
  32 luaA_settype(lua_State *L, const char *type)
  33 {
  34     luaL_getmetatable(L, type);
  35     lua_setmetatable(L, -2);
  36     return 1;
  37 }
  38
  39 DO_ARRAY(luaA_ref, luaA_ref, DO_NOTHING)
  40
  41 #define LUA_OBJECT_FUNCS(type, prefix, lua_type)                               \
  42     static inline type *                                                       \
  43     prefix##_new(lua_State *L)                                                 \
  44     {                                                                          \
  45         type *p = lua_newuserdata(L, sizeof(type));                            \
  46         p_clear(p, 1);                                                         \
  47         luaA_settype(L, lua_type);                                             \
  48         return p;                                                              \
  49     }                                                                          \
  50                                                                                \
  51     static inline int                                                          \
  52     prefix##_push(lua_State *L, type *item)                                    \
  53     {                                                                          \
  54         if(item)                                                               \
  55         {                                                                      \
  56             assert(item->refs.len);                                            \
  57             lua_rawgeti(L, LUA_REGISTRYINDEX, item->refs.tab[0]);              \
  58         }                                                                      \
  59         else                                                                   \
  60             lua_pushnil(L);                                                    \
  61         return 1;                                                              \
  62     }                                                                          \
  63                                                                                \
  64     static inline type *                                                       \
  65     prefix##_ref(lua_State *L)                                                 \
  66     {                                                                          \
  67         if(lua_isnil(L, -1))                                                   \
  68             return NULL;                                                       \
  69         type *item = luaL_checkudata(L, -1, lua_type);                         \
  70         luaA_ref_array_append(&item->refs, luaL_ref(L, LUA_REGISTRYINDEX));    \
  71         return item;                                                           \
  72     }                                                                          \
  73                                                                                \
  74     static inline void                                                         \
  75     prefix##_unref(lua_State *L, type *item)                                   \
  76     {                                                                          \
  77         if(item)                                                               \
  78         {                                                                      \
  79             assert(item->refs.len);                                            \
  80             luaL_unref(L, LUA_REGISTRYINDEX, item->refs.tab[0]);               \
  81             luaA_ref_array_take(&item->refs, 0);                               \
  82         }                                                                      \
  83     }
  84
  85 #endif
  86
  87 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80