Struct GroupNode 

pub struct GroupNode {
    pub member_id: MemberId,
    pub group_id: GroupId,
    pub current_epoch: u64,
    pub last_transition_id: TransitionId,
    pub pending_transition_id: TransitionId,
    pub state: NodeState,
    pub transition_state: TransitionState,
    /* private fields */
}

GBP-layer node.

Owns the framing, AEAD, replay window, FSM and control plane. Sub-protocol semantics live in their own crates and use this type plus a Sealer for outbound traffic and on_wire + the resulting events for inbound traffic.

Fields

member_id: MemberId

Application-level member id.

group_id: GroupId

16-byte group identifier.

current_epoch: u64

Current epoch as observed by the GBP layer (the authoritative epoch lives in the underlying MLS group).

last_transition_id: TransitionId

Last applied transition_id.

pending_transition_id: TransitionId

Pending transition_id (set during PREPARE / READY).

state: NodeState

Node FSM.

transition_state: TransitionState

Transition FSM.

Implementations

impl GroupNode

pub fn new(member_id: MemberId, group_id: GroupId) -> Self

Builds a fresh node in the IDLE state.

pub fn bootstrap_as_creator(&mut self, epoch: u64)

Drives the node from IDLE to ACTIVE as a creator.

pub fn bootstrap_as_joiner(&mut self, epoch: u64, expected_first_tid: u32)

Drives the node from IDLE to ACTIVE as a joiner.

expected_first_tid lets the joiner pre-arm its pending transition state so that the very next EXECUTE_TRANSITION (which will arrive without a preceding PREPARE the joiner could decrypt — that PREPARE was sealed under the pre-Welcome epoch) is accepted by handle_control’s tid-validation matrix. Pass 0 if the joiner recovered out-of-band and is already current.

pub fn drain_events(&mut self) -> Vec<Event>

Drains and returns all queued events.

pub fn member_stream_id(&self, base: u32) -> StreamId

Returns a sender-unique stream_id within the given base class.

This is used so that the receiver’s replay window does not conflate streams that originate from different members.

pub fn send_payload<S: Sealer>( &mut self, seal: &mut S, target: MemberId, stream_type: StreamType, stream_id: StreamId, flags: u16, plaintext: &[u8], ) -> Result<OutboundFrame, NodeError>

Sends an opaque plaintext payload on the given stream.

Used by the sub-protocol clients: each one CBOR-encodes its message and forwards the resulting bytes here.

pub fn send_control<S: Sealer>( &mut self, seal: &mut S, target: MemberId, opcode: ControlOpcode, transition_id: TransitionId, request_id: u32, args: Vec<u8>, ) -> Result<OutboundFrame, NodeError>

Sends a control plane message on Stream 0. Wrapper around GroupNode::send_payload.

Side effect: when the coordinator originates a PREPARE_TRANSITION, it must locally adopt the same pending_transition_id so that the inbound READY / EXECUTE validation matrix in handle_control lines up. Without this, the coordinator never matches its own pending tid against the remote READY frames it expects, and the handshake never completes.

pub fn on_wire<S: Sealer>( &mut self, seal: &mut S, wire: &[u8], ) -> Result<Vec<Event>, NodeError>

Feeds wire bytes to the node.

Performs the §6.2 validation pipeline (version → group_id → epoch → payload_size → transition_id → replay), opens the AEAD payload and either:

• dispatches the parsed control message internally (for StreamType::Control), or
• surfaces an Event::PayloadReceived (for application streams).

Returns every event that was produced as a result.

pub fn apply_transition(&mut self, tid: TransitionId)

Applies a new epoch (called by the coordinator after EXECUTE_TRANSITION).

pub fn trigger_resync(&mut self)

Forces the node into the RESYNCING state.