1 files changed, 45 insertions, 0 deletions
diff --git a/src/utility.c b/src/utility.c
new file mode 100644
index 0000000..d42be1f
--- /dev/null
+++ b/src/utility.c
@@ -0,0 +1,45 @@
+/* LuaEvent - Copyright (C) 2007 Thomas Harning <harningt@gmail.com>
+ * Licensed as LGPL - See doc/COPYING for details */
+#include "utility.h"
+#include <lauxlib.h>
+
+#define WEAK_REF_LOCATION le_register_utility
+
+static void get_weakref_table(lua_State* L) {
+	lua_pushlightuserdata(L, WEAK_REF_LOCATION);
+	lua_gettable(L, LUA_REGISTRYINDEX);
+}
+
+void le_weak_ref(lua_State* L, void* ptr, int idx) {
+	get_weakref_table(L);
+	lua_pushlightuserdata(L, ptr);
+	if(idx < 0) idx-=2;
+	lua_pushvalue(L, idx);
+	lua_settable(L, -3);
+}
+void le_weak_unref(lua_State* L, void* ptr) {
+	get_weakref_table(L);
+	lua_pushlightuserdata(L, ptr);
+	lua_pushnil(L);
+	lua_settable(L, -3);
+}
+
+void le_weak_get(lua_State* L, void* ptr) {
+	get_weakref_table(L);
+	lua_pushlightuserdata(L, ptr);
+	lua_gettable(L, -2);
+}
+
+static void push_weak_table(lua_State* L, const char* mode) {
+	lua_newtable(L);
+	lua_createtable(L,0,1);
+	lua_pushstring(L,mode);
+	lua_setfield(L,-2,"__mode");
+	lua_setmetatable(L,-2);
+}
+
+void le_register_utility(lua_State* L) {
+	lua_pushlightuserdata(L, WEAK_REF_LOCATION);
+	push_weak_table(L, "v");
+	lua_settable(L, LUA_REGISTRYINDEX);
+}