moqtap-codec 0.5.0

//! Draft-12 types.

/// Object status values, from MoQ Transport draft-12 Section 9.2.1.1
/// "Object Status".
///
/// Draft-12 assigns 0x0, 0x1, 0x3 and 0x4, the same four as draft-11. Of every
/// other value the section says: "Any other value SHOULD be treated as a
/// protocol error and terminate the session with a Protocol Violation".
/// [`ObjectStatus::from_u64`] answers `None` for 0x2, for 0x5, and for
/// everything else the draft leaves unassigned.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
pub enum ObjectStatus {
    /// Normal object. Implicit for any non-zero length object; zero-length
    /// objects encode it explicitly.
    Normal = 0,
    /// The object does not exist at any publisher and will not be published in
    /// the future.
    ObjectDoesNotExist = 1,
    /// End of Group. Object ID is one greater than the largest object produced
    /// in the group identified by the Group ID; 0 means the group is empty.
    EndOfGroup = 3,
    /// End of Track. Either Group ID is the largest group produced in the track
    /// and Object ID is one greater than the largest object in that group, or
    /// Group ID is one greater than the largest group produced and Object ID is
    /// zero.
    EndOfTrack = 4,
}

impl ObjectStatus {
    /// Every status draft-12 assigns, in ascending wire order.
    ///
    /// This is exactly the set [`ObjectStatus::from_u64`] accepts. Any other
    /// value is one the draft does not assign.
    pub const ALL: &[ObjectStatus] = &[
        ObjectStatus::Normal,
        ObjectStatus::ObjectDoesNotExist,
        ObjectStatus::EndOfGroup,
        ObjectStatus::EndOfTrack,
    ];

    /// Convert a raw u64 to an `ObjectStatus`, or `None` if draft-12 does not
    /// assign that value.
    pub fn from_u64(v: u64) -> Option<Self> {
        match v {
            0 => Some(ObjectStatus::Normal),
            1 => Some(ObjectStatus::ObjectDoesNotExist),
            3 => Some(ObjectStatus::EndOfGroup),
            4 => Some(ObjectStatus::EndOfTrack),
            _ => None,
        }
    }

    /// Return the wire value.
    pub fn as_u64(self) -> u64 {
        self as u64
    }
}