Struct FetchObjectHeader 

pub struct FetchObjectHeader {
    pub group_id: VarInt,
    pub subgroup_id: VarInt,
    pub object_id: VarInt,
    pub publisher_priority: u8,
    pub extension_headers_length: VarInt,
    pub extensions: Vec<u8>,
    pub object_status: ObjectStatus,
    pub payload_length: VarInt,
}

Object within a fetch stream (draft-10).

Uses extension_headers_length instead of extension_count.

Fields

group_id: VarInt

Group identifier.

subgroup_id: VarInt

Subgroup identifier within the group.

object_id: VarInt

Object identifier within the subgroup.

publisher_priority: u8

Publisher priority for delivery ordering.

extension_headers_length: VarInt

Total byte length of extension headers, as it arrived.

Advisory on encode. Every encoder here writes VarInt::from_usize(self.extensions.len()) and never reads this field, so a hand-built header whose stated length disagrees with the bytes beside it goes on the wire with the derived length and is read back consistent. Decoding always sets the two together, so a value that came off the wire never disagrees.

It is kept because it is what the peer stated, which is not always recoverable from the bytes: a non-minimal varint length encodes the same number in more bytes, and a relay that must forward the block unchanged has to know which it saw.

extensions: Vec<u8>

Raw extension bytes (opaque).

object_status: ObjectStatus

Status of this object.

payload_length: VarInt

Length of the object payload in bytes.

Implementations

impl FetchObjectHeader

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

Encode the fetch object header into the buffer.

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

Encode the header, refusing a status the framing cannot carry.

Section 9.4.4 puts the Object Status field on the wire only when the Object Payload Length is zero, and Section 9.1.1.1 says “Any object with a status code other than zero MUST have an empty payload”. A non-zero status paired with a non-zero payload length therefore has no encoding at all: Self::encode drops the status and the peer reads an ordinary object, which is a different object from the one the caller described. This refuses instead.

The datagram types on this draft already refuse the same pairing. These two did not, and they are the ones a publisher writes on every stream.

Errors

CodecError::InvalidField if a non-zero Object Status is paired with a non-zero Object Payload Length.

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

Decode a fetch object header from the buffer.

Trait Implementations

impl Clone for FetchObjectHeader

fn clone(&self) -> FetchObjectHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FetchObjectHeader

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

Formats the value using the given formatter.

impl Eq for FetchObjectHeader

impl PartialEq for FetchObjectHeader

fn eq(&self, other: &FetchObjectHeader) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FetchObjectHeader