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 first, by wide_type_refusal, which decodes it in full so stream_type_error can tell a padding or SETUP stream — both assigned, both several bytes wide — from a Type Table 3 does not assign. Only the last of those ends the session.

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

Serialize the header exactly as its Type byte describes it.

Infallible, and so willing to write a Type draft-19 Section 11.4.2 tells an endpoint to reject — including a reserved-mode Type this module’s own Self::decode refuses to read back. Prefer Self::encode_checked, which refuses those Types instead.

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

Serialize the header, refusing a Type value draft-19 forbids.

Errors with CodecError::InvalidField for exactly the Types draft-19 Section 11.4.2 lists as invalid (the same set Self::decode refuses), before any byte is written, so a refused header leaves buf untouched. Everything else is written by Self::encode.

The check belongs on the encode side as well as the decode side because the two halves would otherwise disagree about which streams exist: a reserved-mode header written by Self::encode cannot be read back by Self::decode, and a codec used to rewrite captured traffic would emit a stream it could not then parse.

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.

3 never comes back from Self::decode, which refuses the Types carrying it. header_type is a public field, so a hand-built header can still report it; Self::encode_checked is what refuses to put one on the wire.

pub fn is_end_of_group(&self) -> bool

pub fn is_first_object(&self) -> bool

true when the FIRST_OBJECT bit (0x40) is set, signaling the first object on this stream is the original publisher’s first object in the subgroup. Added in draft-18.

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.