Struct Hello 

pub struct Hello {
    pub versions: Vec<u64>,
    pub max_header_bytes: u64,
    pub max_transfers: u64,
    pub capabilities: Vec<u64>,
    pub required_capabilities: Vec<u64>,
    pub guarantees_offered: Option<GuaranteeSet>,
    pub guarantees_required: Option<GuaranteeSet>,
}

HELLO header: connection negotiation input.

Fields

versions: Vec<u64>

Wire protocol versions the sender supports.

max_header_bytes: u64

Largest header the sender is willing to receive.

max_transfers: u64

Advisory concurrent inbound transfer count.

capabilities: Vec<u64>

Capability codes the sender supports.

required_capabilities: Vec<u64>

Capability codes the sender requires the peer to support.

guarantees_offered: Option<GuaranteeSet>

Guarantee set the sender can honour (key 5).

None means the default set: an absent key and GuaranteeSet::CORE are the same declaration, which is why a v0 HELLO is unchanged on the wire.

guarantees_required: Option<GuaranteeSet>

Guarantee set the sender requires of the peer (key 6).

MUST be reachable by guarantees_offered on every dimension: requiring what you cannot honour yourself is a configuration error (docs/PROTOCOL.md §6.1), and a decoder rejects it.

Implementations

impl Hello

pub fn v0(max_header_bytes: u64, max_transfers: u64) -> Hello

The HELLO a v0 implementation sends: no guarantee declarations, so core offered and core required.

pub fn offered(&self) -> GuaranteeSet

The set this HELLO offers; an absent declaration means core.

pub fn required(&self) -> GuaranteeSet

The set this HELLO requires; an absent declaration means core.

pub fn encode(&self) -> Vec<u8>

Encodes the header.

pub fn encode_into(&self, out: &mut Vec<u8>)

Appends the encoded header to out, for a send path that reuses a buffer (B-250). The canonical form has one implementation and this is it; Self::encode is a wrapper.

pub fn decode(bytes: &[u8]) -> Result<Hello, HeaderError>

Decodes the header.

Trait Implementations

impl Clone for Hello

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Hello

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

Formats the value using the given formatter.

impl Eq for Hello

impl PartialEq for Hello

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Hello