degesch: Lua: use references for hook callbacks

Don't associate the callback with the full userdata object,
we'll need this for something else.

1 files changed, 8 insertions, 10 deletions

diff --git a/degesch.c b/degesch.c
index 0a8d4b5..b66114b 100644
--- a/degesch.c
+++ b/degesch.c
@@ -7549,6 +7549,7 @@ struct lua_hook
 {
 	struct lua_plugin *plugin;          ///< The plugin we belong to
 	enum lua_hook_type type;            ///< Type of the hook
+	int ref_callback;                   ///< Reference to the callback
 	union
 	{
 		struct hook hook;               ///< Hook base structure
@@ -7581,6 +7582,9 @@ lua_hook_unhook (lua_State *L)
 		break;
 	}
 
+	luaL_unref (L, LUA_REGISTRYINDEX, hook->ref_callback);
+	hook->ref_callback = LUA_REFNIL;
+
 	// The hook no longer has to stay alive
 	hook->type = XLUA_HOOK_DEFUNCT;
 	lua_cache_invalidate (L, hook);
@@ -7668,10 +7672,8 @@ lua_input_hook_filter (struct input_hook *self, struct buffer *buffer,
 
 	lua_pushcfunction (L, lua_plugin_error_handler);
 
+	lua_rawgeti (L, LUA_REGISTRYINDEX, hook->ref_callback);
 	lua_rawgetp (L, LUA_REGISTRYINDEX, hook);  // 1: hook
-	lua_getuservalue (L, -1);                  // Retrieve function
-	lua_insert (L, -2);                        // Swap with the hook
-
 	lua_plugin_push_buffer (plugin, buffer);   // 2: buffer
 	lua_pushstring (L, input);                 // 3: input
 
@@ -7706,10 +7708,8 @@ lua_irc_hook_filter (struct irc_hook *self, struct server *s, char *message)
 
 	lua_pushcfunction (L, lua_plugin_error_handler);
 
+	lua_rawgeti (L, LUA_REGISTRYINDEX, hook->ref_callback);
 	lua_rawgetp (L, LUA_REGISTRYINDEX, hook);  // 1: hook
-	lua_getuservalue (L, -1);                  // Retrieve function
-	lua_insert (L, -2);                        // Swap with the hook
-
 	lua_plugin_push_server (plugin, s);        // 2: server
 	lua_pushstring (L, message);               // 3: message
 
@@ -7743,9 +7743,8 @@ lua_timer_hook_dispatch (void *user_data)
 
 	lua_pushcfunction (L, lua_plugin_error_handler);
 
+	lua_rawgeti (L, LUA_REGISTRYINDEX, hook->ref_callback);
 	lua_rawgetp (L, LUA_REGISTRYINDEX, hook);  // 1: hook
-	lua_getuservalue (L, -1);                  // Retrieve function
-	lua_insert (L, -2);                        // Swap with the hook
 
 	if (lua_pcall (L, 1, 0, -3))
 	{
@@ -7778,9 +7777,8 @@ lua_plugin_push_hook (struct lua_plugin *plugin, int callback_index,
 	hook->type = type;
 	hook->plugin = plugin;
 
-	// Associate the callback with the hook
 	lua_pushvalue (L, callback_index);
-	lua_setuservalue (L, -2);
+	hook->ref_callback = luaL_ref (L, LUA_REGISTRYINDEX);
 
 	// Make sure the hook doesn't get garbage collected and return it
 	lua_cache_store (L, hook, -1);