`notmuch_database_begin_atomic` and `notmuch_database_end_atomic`
allow multiple database operations to be performed atomically.
`notmuch_database_find_message_by_filename` does exactly what it says.
`notmuch_database_begin_atomic` and `notmuch_database_end_atomic`
allow multiple database operations to be performed atomically.
`notmuch_database_find_message_by_filename` does exactly what it says.