Add tags() method that returns Option<Arc<RwLock<BTreeMap<u64, String>>>>.
The BTreeMap holds available tags in a mail backend and uses the tag's
hash as key.
The method returns an Option because not all backends may support
tagging.
Change folders() signature:
- fn folders(&self) -> FnvHashMap<FolderHash, Folder>;
+ fn folders(&self) -> Result<FnvHashMap<FolderHash, Folder>>;
Imap may not be online, therefore we need the ability to return an
error.
Make startup methods return Results so that the main binary can exit
cleanly instead of using std::process::exit from arbitrary positions,
which exits the process immediately and doesn't run destructors.
Manos Pitsidianakis