Re: simple performance question

[Dirk Luetjens <dirk post lfm rwth-aachen de>]

Hi,

isnīt this worth a note on the "GNOME Tricks and Tips" web page? Not
everybody is digging in the glib sources and they falsely assume
g_list_append is a fast opperation.

Dirk

> >  I have seen, that the g_list_append in glib function always searches the
> >  end of the list, since there is no pointer to the last element. And I have
> >  seen, that a few programs uses this function to set up lists.
> 
> Most lists are short and then do not need any further optimization.
> Places in Gtk and and Gnome where there could be potentially very long
> lists use the following method:
> 
>       struct SomeGtkObject {
> 	     ...
> 	     GList *items_list;
> 	     GList *items_list_end;
>       };
> 
> And to insert an item at the end of the list, you can use the
> following code:
> 
> 	  if (!items_list) {
> 	     items_list = g_list_append (items_list, my_data);
> 	     items_list_end = items_list;
> 	  } else
> 	     items_list_end = g_list_append (items_list_end, my_data)->next;
> 
> So it's not hard to do.  If you will be having very long lists, you
> may want to consider using this method.
>
>
>  Federico