Struct SubgroupObject 

pub struct SubgroupObject {
    pub object_id: VarInt,
    pub extension_headers: Vec<u8>,
    pub payload_length: VarInt,
    pub object_status: Option<ObjectStatus>,
    pub payload: Vec<u8>,
}

One object within a draft-18 subgroup stream. Object IDs are delta-encoded; whether a per-object “properties” block (the draft-18 equivalent of extension headers) is present depends on the PROPERTIES bit on the enclosing SubgroupHeader. Use SubgroupObjectReader to encode/decode.

Fields

object_id: VarInt

extension_headers: Vec<u8>

Raw properties bytes, excluding the byte-length prefix that precedes them on the wire. Empty unless the subgroup header sets the PROPERTIES bit, or when the block is present but zero-length. Opaque: SubgroupObjectReader::write_object re-emits the prefix and these bytes verbatim.

payload_length: VarInt

object_status: Option<ObjectStatus>

The object’s status, carried on the wire only when payload_length is zero: a zero-length object encodes a status code in place of its payload. None with a zero payload_length is written as ObjectStatus::Normal, the status draft-18 Section 11.2.1.1 gives an empty object.

Typed rather than a raw code. The wire field is a varint with room for any value, and draft-18 assigns three of them; the decoder refuses the rest, and this type is that same refusal on the encode side — 0x1 and 0x2 cannot be named here, so SubgroupObjectReader::write_object cannot emit a status this module’s own decoder would reject.

payload: Vec<u8>

Implementations

impl SubgroupObject

pub fn status(&self) -> ObjectStatus

The object’s status, with the one draft-18’s encoding elides filled in.

A subgroup object states its status only when its Object Payload Length is zero. An object that carries bytes therefore has no status field, and its status is ObjectStatus::Normal — the only status draft-18 Section 11.2.1.1 permits a payload, so the only one such an object could have had.

pub fn properties_permitted(&self) -> bool

Whether this object’s status is allowed to carry the properties it has.

Draft-18 Section 11.2.1.2: “Any Object with status Normal can have properties (Section 2.5). If an endpoint receives properties on an Object with status that is not Normal, it MUST close the session with a PROTOCOL_VIOLATION.”

So this is false for exactly one shape: a non-empty properties block on an object whose status is not ObjectStatus::Normal. An object with no properties is fine at any status, and an object at Normal may carry any properties. A zero-length block is “no properties” here and not a violation — Section 11.4.2 requires it of an object on a PROPERTIES subgroup stream that has none: “Objects with no properties set Properties Length to 0.”

Neither SubgroupObjectReader::read_object nor SubgroupObjectReader::write_object applies this itself, which is a deliberate contrast with the payload rule beside it. A status next to a payload has no encoding — the two share a position on the wire — so the writer refuses it as unrepresentable. Properties next to a status encode fine; the frame is well formed and merely non-conforming, and a codec that could not read or write it could not reproduce a capture containing one. The rule addresses an endpoint receiving such an Object, so the endpoint is where it is enforced, and this is what it asks.

The datagram carrier is the exception, and the draft is what makes it one: Section 11.3.1 states the same rule again as a per-datagram framing rule, so DatagramHeader::decode refuses it outright.

Trait Implementations

impl Clone for SubgroupObject

fn clone(&self) -> SubgroupObject

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubgroupObject

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

Formats the value using the given formatter.