awesome/common/luaobject.h

210 lines
7.5 KiB
C

/*
* luaobject.h - useful functions for handling Lua objects
*
* Copyright © 2009 Julien Danjou <julien@danjou.info>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#ifndef AWESOME_COMMON_LUAOBJECT
#define AWESOME_COMMON_LUAOBJECT
#include <lauxlib.h>
#include "common/array.h"
static inline int
luaA_settype(lua_State *L, const char *type)
{
luaL_getmetatable(L, type);
lua_setmetatable(L, -2);
return 1;
}
#define LUAA_OBJECT_REGISTRY_KEY "awesome.object.registry"
void luaA_object_setup(lua_State *);
void * luaA_object_incref(lua_State *, int, int);
void luaA_object_decref(lua_State *, int, void *);
/** Store an item in the environment table of an object.
* \param L The Lua VM state.
* \param ud The index of the object on the stack.
* \param iud The index of the item on the stack.
* \return The item reference.
*/
static inline void *
luaA_object_ref_item(lua_State *L, int ud, int iud)
{
/* Get the env table from the object */
lua_getfenv(L, ud);
void *pointer = luaA_object_incref(L, -1, iud < 0 ? iud - 1 : iud);
/* Remove env table */
lua_pop(L, 1);
return pointer;
}
/** Unref an item from the environment table of an object.
* \param L The Lua VM state.
* \param ud The index of the object on the stack.
* \param ref item.
*/
static inline void
luaA_object_unref_item(lua_State *L, int ud, void *pointer)
{
/* Get the env table from the object */
lua_getfenv(L, ud);
/* Decrement */
luaA_object_decref(L, -1, pointer);
/* Remove env table */
lua_pop(L, 1);
}
/** Push an object item on the stack.
* \param L The Lua VM state.
* \param ud The object index on the stack.
* \param pointer The item pointer.
* \return The number of element pushed on stack.
*/
static inline int
luaA_object_push_item(lua_State *L, int ud, void *pointer)
{
/* Get env table of the object */
lua_getfenv(L, ud);
/* Push key */
lua_pushlightuserdata(L, pointer);
/* Get env.pointer */
lua_rawget(L, -2);
/* Remove env table */
lua_remove(L, -2);
return 1;
}
static inline void
luaA_object_registry_push(lua_State *L)
{
lua_pushliteral(L, LUAA_OBJECT_REGISTRY_KEY);
lua_rawget(L, LUA_REGISTRYINDEX);
}
/** Reference an object and return a pointer to it.
* That only works with userdata, table, thread or function.
* \param L The Lua VM state.
* \param oud The object index on the stack.
* \return The object reference, or NULL if not referencable.
*/
static inline void *
luaA_object_ref(lua_State *L, int oud)
{
luaA_object_registry_push(L);
void *p = luaA_object_incref(L, -1, oud < 0 ? oud - 1 : oud);
lua_pop(L, 1);
return p;
}
/** Unreference an object and return a pointer to it.
* That only works with userdata, table, thread or function.
* \param L The Lua VM state.
* \param oud The object index on the stack.
*/
static inline void
luaA_object_unref(lua_State *L, void *pointer)
{
luaA_object_registry_push(L);
luaA_object_decref(L, -1, pointer);
lua_pop(L, 1);
}
/** Push a referenced object onto the stack.
* \param L The Lua VM state.
* \param pointer The object to push.
* \return The number of element pushed on stack.
*/
static inline int
luaA_object_push(lua_State *L, void *pointer)
{
luaA_object_registry_push(L);
lua_pushlightuserdata(L, pointer);
lua_rawget(L, -2);
lua_remove(L, -2);
return 1;
}
#define LUA_OBJECT_HEADER
/** Generic type for all objects.
* All Lua objects can be casted to this type.
*/
typedef struct
{
LUA_OBJECT_HEADER
} lua_object_t;
#define LUA_OBJECT_FUNCS(type, prefix, lua_type) \
static inline type * \
prefix##_new(lua_State *L) \
{ \
type *p = lua_newuserdata(L, sizeof(type)); \
p_clear(p, 1); \
luaA_settype(L, lua_type); \
lua_newtable(L); \
lua_newtable(L); \
lua_setmetatable(L, -2); \
lua_setfenv(L, -2); \
return p; \
} \
\
static inline int \
prefix##_push(lua_State *L, type *item) \
{ \
return luaA_object_push(L, item); \
} \
\
static inline type * \
prefix##_ref(lua_State *L, int ud) \
{ \
return luaA_object_ref(L, ud); \
} \
\
static inline void \
prefix##_unref(lua_State *L, type *item) \
{ \
luaA_object_unref(L, item); \
} \
\
static inline int \
prefix##_push_item(lua_State *L, type *item, void *ref) \
{ \
prefix##_push(L, item); \
luaA_object_push_item(L, -1, ref); \
lua_remove(L, -2); \
return 1; \
}
/** Garbage collect a Lua object.
* \param L The Lua VM state.
* \return The number of elements pushed on stack.
*/
static inline int
luaA_object_gc(lua_State *L)
{
return 0;
}
#endif
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