Re: [Evolution-hackers] Support for LIST-EXTENDED's SUBSCRIBED parameter

[Philip Van Hoof <spam pvanhoof be>]

Oh, and it's wrong.

It seems that an IMAP server can send an multiple parameters after the
directory separator for a namespace. So after the directory separator,
the ptr should be read skipping each \"string\" until "))" is seen.

And it seems that it's a skiplist, so a parameter can be a
"SOMETHING" ("Some setting" "Some more"). hrm ... that's more work :)


On Thu, 2007-12-20 at 21:46 +0100, Philip Van Hoof wrote:
> This is some first piece of code to parse "the other" namespaces
> 
> In: imap_connect_online 
> 
> 
> 		result = camel_imap_response_extract (store, response, "NAMESPACE", ex);
> 		if (!result)
> 			goto done;
> 
> #if 0
> 		/* new code... */
> 		namespaces = imap_parse_namespace_response (result);
> 		imap_namespaces_destroy (namespaces);
> 		/* end new code */
> #endif
> 
> 		name = camel_strstrcase (result, "NAMESPACE ((");
> 		if (name) {
> 			gboolean first = TRUE;
> 			gboolean cont = TRUE;
> 			name += 10;
> 
> 			while (cont) {
> 				char *sep, *str = NULL;
> 
> 				while (*name == ' ')
> 					name++;
> 
> 				if (*name == '(' && *(name+1) == '(') {
> 					name += 2;
> 					if (first)
> 						store->namespace = imap_parse_string ((const char **) &name, &len);
> 					else
> 						str = imap_parse_string ((const char **) &name, &len);
> 
> 					if (name && *name++ == ' ') {
> 						sep = imap_parse_string ((const char **) &name, &len);
> 						if (sep) {
> 							if (first)
> 								store->dir_sep = *sep;
> 							g_free (sep);
> 						}
> 						if (*name != ')' || *(name+1) != ')') {
> 							cont = FALSE;
> 							break;
> 						}
> 						/* The )) */
> 						name += 2;
> 					}
> 				} else if (!strncmp (name, "NIL", 3))
> 					name += 3;
> 
> 				if (!name)
> 					cont = FALSE;
> 
> 				if (str) {
> printf ("Other namespace:%s\n", str);
> 					g_free (str);
> 				}
> 				first = FALSE;
> 			}
> 		}
> 		g_free (result);
> 	}
> 
> On Thu, 2007-12-20 at 14:06 +0100, Philip Van Hoof wrote:
> > I further changed Camel-lite in such a way that only the following
> > protocol conversation takes place:
> > 
> > if CAPABILITIES contains NAMESPACE
> >   -> NAMESPACE
> >   <- NAMESPACE (("namespace that matters" "dir_sep_char") ... )
> >   # Camel ignores the other namespaces (this is bad!)
> >   item = "namespace that matters" + dir_sep_char + "*" or "%"
> > else
> >   namespace = false
> >   item = "*"
> > endif
> > 
> > Note that usually "namespace that matters" is simply "INBOX". Note that
> > Camel ignores all not-first namespaces (and that supporting all
> > namespaces implies a format change of the CamelStoreSummary's caching).
> > 
> > Then this is done to know the subscription state of INBOX (and counts as
> > a roundtrip, I'm still figuring out how I can avoid this one as I think
> > it's unnecessary):
> > 
> > (now, this only happens if namespace != "")
> > 
> > if capabilities contains LIST-EXTENDED
> >   -> LIST (SUBSCRIBED) "" INBOX
> >   <- LIST (\Subscribed) INBOX ...
> > else
> >   ->  LIST "" INBOX
> >   <- LIST INBOX ...
> >   ->  LSUB "" INBOX
> >   <- LSUB INBOX ...
> > endif
> > 
> > This is getting the list of folders. Either item is "namespace.*' or
> > it's "*". Note that requesting "*" is a very bad idea for very large
> > folder lists (it's recursive, not all IMAP servers will like you for
> > doing this, and it'll be a lot slower than requesting "%" in stead).
> > 
> > In case you don't request a recursive list, Camel puts "%" in stead of
> > "*", but note that most of Evolution's code requests a recursive one (so
> > it'll at least once occur that a recursive is requested, and therefore
> > it'll request it as "*" anyway, or at least that's what I saw happening
> > when analysing the traffic).
> > 
> > Better would indeed be to request a new list each time you click-open a
> > tree node, and request "%" in stead. This might not be practical for the
> > UI developer, though.
> > 
> > Here the LIST-EXTENDED changes kick into action.
> > 
> > if capabilities contains LIST-EXTENDED
> >   -> LIST (SUBSCRIBED) "" item
> >   <- LIST (\NonExistent \Subscribed) ...
> >   <- LIST (\Subscribed) ...
> >   <- ...
> > else
> >   -> LIST "" item
> >   <- LIST ...
> >   -> LSUB "" item
> >   <- LSUB ...
> > endif
> > 
> > Now. What Evolution does (it doesn't support the LIST-EXTENDED case) is
> > merge the LIST and LSUB together while marking items in LSUB as
> > CAMEL_FOLDER_SUBSCRIBED. Marking them is fine, of course, but merging
> > them together is utterly wrong. 
> > 
> > Courier is one of the IMAP server that don't do housekeeping of LSUB
> > when you for example delete a folder yet don't unsubscribed it first.
> > The net result is that with Evolution you get folder-nodes that don't
> > exist at the server.
> > 
> > For the user this means that when he clicks on that folder-node, that he
> > gets an error about the folder not existing.
> > 
> > Of course in Courier you can have subfolders of folders that don't
> > exist. Oh the joys of IMAP :) (and the joys of server people disagreeing
> > on the interpretation of the standard).
> > 
> > As how I see it should the IMAP server give in its LIST response a
> > \NonExistant and/or \NoSelect flag for such folders. But should not omit
> > them in LIST. But merging LSUB and LIST together is even more wrong. At
> > least in my opinion (you end up showing folders to the user that simply
> > don't exist on the server).
> > 
> > Note: A greyish tree node that presents a parent for child-folders when
> > it ain't selectable ... would be a more correct UI presentation of such
> > a \NoSelect parent folder (or, placeholder in the folder tree).
> > 
> > Note. An example is the [GMail] folder of Google IMAP. Google's IMAP
> > server is one of the first times that I saw \NoSelect being actively
> > used by an IMAP server in a default-ish way.
> > 
> > Evolution will soon get a lot of GMail IMAP users ...
> > 
> > Sounds like something to correctly handle from now on.
> > 
> > 
> > 
> > 
> > On Wed, 2007-12-19 at 21:32 +0100, Philip Van Hoof wrote:
> > > The net result of this patch is less round trips when connecting with an
> > > IMAP server that has support for LIST-EXTENDED.
> > > 
> > > http://tinymail.org/trac/tinymail/changeset/3155
> > > 
> > > Note that Evolution merges LIST and LSUB together. This is wrong
> > > behaviour. An item not in LIST yet in LSUB simply doesn't exist.
> > > 
> > > 
> > -- 
> > Philip Van Hoof, freelance software developer
> > home: me at pvanhoof dot be 
> > gnome: pvanhoof at gnome dot org 
> > http://pvanhoof.be/blog
> > http://codeminded.be
> > 
> > 
> > 
> > 
> > _______________________________________________
> > Evolution-hackers mailing list
> > Evolution-hackers gnome org
> > http://mail.gnome.org/mailman/listinfo/evolution-hackers
-- 
Philip Van Hoof, freelance software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://pvanhoof.be/blog
http://codeminded.be