Re: [Evolution-hackers] camel local provider and Bug 213072

[Philip Van Hoof <spam pvanhoof be>]

Hey Seb,

Thanks for your interest in wanting to improve Camel. Multiple projects
would benefit from your contributions, so I'll explain how you can
implement what you want to try to do (not sure if your specific feature
makes a lot sense, but nevertheless is it good that you are at least
reading code in stead of just whining feature-requests, right?) :-)

Because CamelSpoolFolder (camel/providers/local/camel-spool-folder.c)
does not implement it, it's going to be the default expunge of
CamelLocalFolder (camel/providers/local/camel-local-folder.c). That's
the case because the CamelSpoolFolder inherits the abstract
CamelLocalFolder type. 

Else it would have been the default implementation of CamelFolder, which
would just print a warning that it's not implemented (camel-folder.c)


These are the current methods being implemented by CamelSpoolFolder:

static void
camel_spool_folder_class_init(CamelSpoolFolderClass *klass)
{
	CamelLocalFolderClass *lklass = (CamelLocalFolderClass *)klass;

	parent_class = (CamelFolderClass *)camel_mbox_folder_get_type();

	lklass->create_summary = spool_create_summary;
	lklass->lock = spool_lock;
	lklass->unlock = spool_unlock;
}


static void
local_expunge(CamelFolder *folder, CamelException *ex)
{
	d(printf("expunge\n"));

	/* Just do a sync with expunge, serves the same purpose */
	/* call the callback directly, to avoid locking problems */
	CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(folder))->sync(folder, TRUE, ex);
}

The sync function pointer will resolve to this implementation:

static void
local_sync(CamelFolder *folder, gboolean expunge, CamelException *ex)
{
	CamelLocalFolder *lf = CAMEL_LOCAL_FOLDER(folder);

	d(printf("local sync '%s' , expunge=%s\n", folder->full_name, expunge?"true":"false"));

	if (camel_local_folder_lock(lf, CAMEL_LOCK_WRITE, ex) == -1)
		return;

	camel_object_state_write(lf);

	/* if sync fails, we'll pass it up on exit through ex */
	camel_local_summary_sync((CamelLocalSummary *)folder->summary, expunge, lf->changes, ex);
	camel_local_folder_unlock(lf);

	if (camel_folder_change_info_changed(lf->changes)) {
		camel_object_trigger_event(CAMEL_OBJECT(folder), "folder_changed", lf->changes);
		camel_folder_change_info_clear(lf->changes);
	}
}



If you want to implement a specialised version for "spool" folders, fill
in the function pointer like this:

static void
camel_spool_folder_class_init(CamelSpoolFolderClass *klass)
{
	CamelLocalFolderClass *lklass = (CamelLocalFolderClass *)klass;
+	CamelFolderClass *camel_folder_class = CAMEL_FOLDER_CLASS(camel_local_folder_class);

	parent_class = (CamelFolderClass *)camel_mbox_folder_get_type();

	lklass->create_summary = spool_create_summary;
	lklass->lock = spool_lock;
	lklass->unlock = spool_unlock;

	camel_folder_class->expunge = spool_expunge;

}

And implement it:

+ static void
+ spool_expunge(CamelFolder *folder, CamelException *ex)
+ {
+     /* Call the method on super */
+     parent_class->expunge (folder, ex);
+     return;
+ }


On Sun, 2007-01-14 at 21:00 +0000, Seb James wrote:
> Hi List,
> 
> I'm looking at the local provider for camel, written by Michael Zucchi.
> It seems to be related to Bug 213072, which is now rather old, and which
> affects me.
> 
> I'm trying to understand the code to begin with.
> 
> I use a standard unix mail spool as my inbox, and I am wondering why it
> is that I can't expunge deleted messages from the spool. The spool just
> gets bigger and bigger, filling up with messages, flagged as deleted.
> 
> So, question one to get me started is: What function in e-d-s carries
> out message expunging, as distinct from message deletion?
> 
> regards,
> 
> Seb James
> 
> 
> _______________________________________________
> Evolution-hackers mailing list
> Evolution-hackers gnome org
> http://mail.gnome.org/mailman/listinfo/evolution-hackers
-- 
Philip Van Hoof, software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://www.pvanhoof.be/blog