Struct SubgroupHeader 

pub struct SubgroupHeader {
    pub header_type: u8,
    pub track_alias: VarInt,
    pub group_id: VarInt,
    pub subgroup_id: VarInt,
    pub publisher_priority: Option<u8>,
}

Fields

header_type: u8

track_alias: VarInt

group_id: VarInt

subgroup_id: VarInt

publisher_priority: Option<u8>

Implementations

impl SubgroupHeader

pub fn decode(buf: &mut impl Buf) -> Result<Self, CodecError>

Decode a subgroup header, Type field included.

A Type spelled in more than one byte is refused before it is narrowed, by wide_type_refusal: every Type the subgroup form admits is a single byte, and the wider Types Table 3 assigns are not subgroup headers.

pub fn encode(&self, buf: &mut impl BufMut)

Serialize the header exactly as its type byte describes it.

The type byte is taken as the authority on framing and is written through unexamined, which is what makes this infallible. A value built by hand can therefore name a type draft-17 forbids — the reserved SUBGROUP_ID_MODE 0b11 above all — and produce a stream the receiver must answer with a PROTOCOL_VIOLATION. Prefer Self::encode_checked, which refuses such a header instead of emitting it.

pub fn encode_checked(&self, buf: &mut impl BufMut) -> Result<(), CodecError>

Serialize the header, refusing a type value draft-17 does not define.

The accepted set is the one Self::decode accepts, so bytes this writes always parse back through this module rather than being refused by the peer. Section 10.4.2 lists the excluded values under “The following Type values are invalid”, and a receiver that follows it closes the session rather than reading the stream, so writing one loses the whole session and not merely the stream.

Errors with CodecError::InvalidField before any byte is written, so a refused header leaves buf untouched rather than half a header the next write would run into.

pub fn has_properties(&self) -> bool

pub fn subgroup_id_mode(&self) -> u8

The subgroup-ID mode: (header_type & 0x06) >> 1.

0 = no subgroup ID on the wire and it is zero; 1 = the subgroup ID is the first object’s ID; 2 = an explicit ID follows the Group ID; 3 = reserved. Exposed because the mask is module-private and dispatch::AnySubgroupHeader::subgroup_id_mode cannot read it.

A decoded header never reports 3: draft-17 Section 10.4.2 lists every type value carrying that mode as invalid and Self::decode refuses them. It remains reachable on a header built by hand, which is what Self::encode_checked exists to catch.

pub fn is_end_of_group(&self) -> bool

Trait Implementations

impl Clone for SubgroupHeader

fn clone(&self) -> SubgroupHeader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SubgroupHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.