Function read_next_directory_page 

pub async fn read_next_directory_page<E, C>(
    enumerator: &E,
    path: &DavPath,
    state: &mut DavDirectoryPageState<E::Cursor>,
    requested_entries: usize,
    limits: DavDirectoryPageLimits,
    cancellation: &C,
) -> Result<Option<DavValidatedDirectoryPage<E::Entry>>, DavDirectoryReadError>
where
    E: DavDirectoryEnumerator,
    C: DavCancellation,

Requests and validates the next directory page.

Cancellation is checked before every backend call. The product cursor remains opaque and is moved into the state only after the page passes all validation. An invalid product page poisons the state so subsequent calls return the same validation error without repeating the backend request.

Errors

Returns an error on cancellation, backend failure, exhausted limits, or an invalid page.