src/utility.c

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/* LuaEvent - Copyright (C) 2007 Thomas Harning <harningt@gmail.com>
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 * Licensed as LGPL - See doc/COPYING for details */
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#include "utility.h"
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#include <lauxlib.h>
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#define WEAK_REF_LOCATION le_register_utility
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static void get_weakref_table(lua_State* L) {
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	lua_pushlightuserdata(L, WEAK_REF_LOCATION);
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	lua_gettable(L, LUA_REGISTRYINDEX);
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}
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void le_weak_ref(lua_State* L, void* ptr, int idx) {
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	get_weakref_table(L);
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	lua_pushlightuserdata(L, ptr);
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	if(idx < 0) idx-=2;
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	lua_pushvalue(L, idx);
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	lua_settable(L, -3);
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}
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void le_weak_unref(lua_State* L, void* ptr) {
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	get_weakref_table(L);
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	lua_pushlightuserdata(L, ptr);
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	lua_pushnil(L);
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	lua_settable(L, -3);
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}
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void le_weak_get(lua_State* L, void* ptr) {
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	get_weakref_table(L);
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	lua_pushlightuserdata(L, ptr);
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	lua_gettable(L, -2);
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}
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static void push_weak_table(lua_State* L, const char* mode) {
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	lua_newtable(L);
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	lua_createtable(L,0,1);
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	lua_pushstring(L,mode);
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	lua_setfield(L,-2,"__mode");
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	lua_setmetatable(L,-2);
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}
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void le_register_utility(lua_State* L) {
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	lua_pushlightuserdata(L, WEAK_REF_LOCATION);
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	push_weak_table(L, "v");
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	lua_settable(L, LUA_REGISTRYINDEX);
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}