/* * luaobject.c - useful functions for handling Lua objects * * Copyright © 2009 Julien Danjou * * 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. * */ #include "common/luaobject.h" /** Setup the object system at startup. * \param L The Lua VM state. */ void luaA_object_setup(lua_State *L) { /* Push identification string */ lua_pushliteral(L, LUAA_OBJECT_REGISTRY_KEY); /* Create an empty table */ lua_newtable(L); /* Create an empty metatable */ lua_newtable(L); /* Set this empty table as the registry metatable. * It's used to store the number of reference on stored objects. */ lua_setmetatable(L, -2); /* Register table inside registry */ lua_rawset(L, LUA_REGISTRYINDEX); } /** Increment a object reference in its store table. * \param L The Lua VM state. * \param tud The table index on the stack. * \param oud The object index on the stack. * \return A pointer to the object. */ void * luaA_object_incref(lua_State *L, int tud, int oud) { /* Get pointer value of the item */ void *pointer = (void *) lua_topointer(L, oud); /* Not referencable. */ if(!pointer) { lua_remove(L, oud); return NULL; } /* Push the pointer (key) */ lua_pushlightuserdata(L, pointer); /* Push the data (value) */ lua_pushvalue(L, oud < 0 ? oud - 1 : oud); /* table.lightudata = data */ lua_rawset(L, tud < 0 ? tud - 2 : tud); /* refcount++ */ /* Get the metatable */ lua_getmetatable(L, tud); /* Push the pointer (key) */ lua_pushlightuserdata(L, pointer); /* Get the number of references */ lua_rawget(L, -2); /* Get the number of references and increment it */ int count = lua_tonumber(L, -1) + 1; lua_pop(L, 1); /* Push the pointer (key) */ lua_pushlightuserdata(L, pointer); /* Push count (value) */ lua_pushinteger(L, count); /* Set metatable[pointer] = count */ lua_rawset(L, -3); /* Pop metatable */ lua_pop(L, 1); /* Remove referenced item */ lua_remove(L, oud); return pointer; } /** Decrement a object reference in its store table. * \param L The Lua VM state. * \param tud The table index on the stack. * \param oud The object index on the stack. * \return A pointer to the object. */ void luaA_object_decref(lua_State *L, int tud, void *pointer) { if(!pointer) return; /* First, refcount-- */ /* Get the metatable */ lua_getmetatable(L, tud); /* Push the pointer (key) */ lua_pushlightuserdata(L, pointer); /* Get the number of references */ lua_rawget(L, -2); /* Get the number of references and decrement it */ int count = lua_tonumber(L, -1) - 1; lua_pop(L, 1); /* Push the pointer (key) */ lua_pushlightuserdata(L, pointer); /* Hasn't the ref reached 0? */ if(count) lua_pushinteger(L, count); else /* Yup, delete it, set nil as value */ lua_pushnil(L); /* Set meta[pointer] = count/nil */ lua_rawset(L, -3); /* Pop metatable */ lua_pop(L, 1); /* Wait, no more ref? */ if(!count) { /* Yes? So remove it from table */ lua_pushlightuserdata(L, pointer); /* Push nil as value */ lua_pushnil(L); /* table[pointer] = nil */ lua_rawset(L, tud < 0 ? tud - 2 : tud); } } /** Add a signal to an object. * \param L The Lua VM state. * \param oud The object index on the stack. * \param name The name of the signal. * \param ud The index of function to call when signal is emited. */ void luaA_object_add_signal(lua_State *L, int oud, const char *name, int ud) { luaA_checkfunction(L, ud); lua_object_t *obj = lua_touserdata(L, oud); signal_add(&obj->signals, name, luaA_object_ref_item(L, oud, ud)); } /** Remove a signal to an object. * \param L The Lua VM state. * \param oud The object index on the stack. * \param name The name of the signal. * \param ud The index of function to call when signal is emited. */ void luaA_object_remove_signal(lua_State *L, int oud, const char *name, int ud) { luaA_checkfunction(L, ud); lua_object_t *obj = lua_touserdata(L, oud); void *ref = (void *) lua_topointer(L, ud); signal_remove(&obj->signals, name, ref); luaA_object_unref_item(L, oud, ref); lua_remove(L, ud); } /** Emit a signal to an object. * \param L The Lua VM state. * \param oud The object index on the stack. * \param name The name of the signal. * \param nargs The number of arguments to pass to the called functions. */ void luaA_object_emit_signal(lua_State *L, int oud, const char *name, int nargs) { int oud_abs = luaA_absindex(L, oud); lua_object_t *obj = lua_touserdata(L, oud); signal_t *sigfound = signal_array_getbyid(&obj->signals, a_strhash((const unsigned char *) name)); if(sigfound) foreach(ref, sigfound->sigfuncs) { lua_pushvalue(L, oud_abs); for(int i = 0; i < nargs; i++) lua_pushvalue(L, - nargs - 1); luaA_object_push_item(L, oud_abs, (void *) *ref); luaA_dofunction(L, nargs + 1, 0); } lua_pop(L, nargs); } int luaA_object_add_signal_simple(lua_State *L) { luaA_object_add_signal(L, 1, luaL_checkstring(L, 2), 3); return 0; } int luaA_object_remove_signal_simple(lua_State *L) { luaA_object_remove_signal(L, 1, luaL_checkstring(L, 2), 3); return 0; } int luaA_object_emit_signal_simple(lua_State *L) { luaA_object_emit_signal(L, 1, luaL_checkstring(L, 2), lua_gettop(L) - 2); return 0; } // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80