#include #include #include "object-refs.h" static char const * const object_ref_table_name = "GSL.objref"; void object_ref_prepare (lua_State *L) { lua_newtable (L); /* the metatable to define it as a weak table */ lua_newtable (L); lua_pushstring (L, "k"); lua_setfield (L, -2, "__mode"); lua_setmetatable (L, -2); lua_setfield (L, LUA_REGISTRYINDEX, object_ref_table_name); } void object_ref_add (lua_State *L, int key_index, int val_index) { int ref; bool add_table = false; lua_getfield (L, LUA_REGISTRYINDEX, object_ref_table_name); lua_pushvalue (L, key_index); lua_rawget (L, -2); if (lua_isnil (L, -1)) { lua_pop (L, 1); lua_newtable (L); lua_pushvalue (L, val_index); ref = 1; add_table = true; } else { lua_pushvalue (L, val_index); lua_pushvalue (L, val_index); lua_rawget (L, -3); ref = lua_tointeger (L, -1) + 1; lua_pop (L, 1); } lua_pushinteger (L, ref); lua_rawset (L, -3); if (add_table) { lua_pushvalue (L, key_index); lua_insert (L, -2); lua_rawset (L, -3); lua_pop (L, 1); } else lua_pop (L, 2); } void object_ref_remove (lua_State *L, int key_index, int val_index) { lua_getfield (L, LUA_REGISTRYINDEX, object_ref_table_name); lua_pushvalue (L, key_index); lua_rawget (L, -2); if (! lua_isnil (L, -1)) { int ref; lua_pushvalue (L, val_index); lua_pushvalue (L, val_index); lua_rawget (L, -3); ref = lua_tointeger (L, -1); lua_pop (L, 1); if (ref <= 1) lua_pushnil (L); else lua_pushinteger (L, ref - 1); lua_rawset (L, -3); } lua_pop (L, 2); }