Struct StewardList 

pub struct StewardList { /* private fields */ }

An ordered list of steward identities for a range of epochs.

Generated deterministically so all conversation members arrive at the same list. The list covers epochs [election_epoch, election_epoch + len).

Implementations

impl StewardList

pub fn generate( election_epoch: u64, conversation_id: &[u8], member_ids: &[Vec<u8>], sn: usize, config: StewardListConfig, retry_round: u32, ) -> Result<Self, CoreError>

Generate the deterministic steward list. Sorts candidates by SHA256(epoch || retry_round || member_id || conversation_id) and takes the first sn. Errors on empty member_ids or sn outside the config bounds.

pub fn validate( proposed: &[Vec<u8>], election_epoch: u64, conversation_id: &[u8], member_ids: &[Vec<u8>], config: &StewardListConfig, retry_round: u32, ) -> Result<bool, CoreError>

True iff proposed equals what Self::generate would produce for the same parameters. Compares in place — does not allocate a full StewardList.

pub fn epoch_steward(&self, epoch: u64) -> Option<&[u8]>

Nominal epoch steward at index (epoch - election_epoch) % len. Use Self::live_steward_from with the eligibility predicate to skip stewards no longer in the conversation.

pub fn backup_steward(&self, epoch: u64) -> Option<&[u8]>

Nominal backup steward at index (epoch - election_epoch + 1) % len.

pub fn live_epoch_and_backup<F: Fn(&[u8]) -> bool>( &self, epoch: u64, eligible: F, ) -> (Option<&[u8]>, Option<&[u8]>)

Live epoch steward + a distinct backup. Resolving them together stops the epoch-steward walk from landing on the nominal backup and collapsing both roles onto the same identity. Backup is None when fewer than two stewards are eligible.

pub fn live_steward_from<F: Fn(&[u8]) -> bool>( &self, epoch: u64, offset: usize, eligible: F, ) -> Option<&[u8]>

Walk the rotation starting at offset past eligible == false and return the first eligible steward. offset = 0 resolves the epoch steward; offset = 1 resolves the backup. Returns None when the list is exhausted at epoch or no candidate is eligible.

pub fn is_exhausted(&self, epoch: u64) -> bool

true once every steward has served — the list covers [election_epoch, election_epoch + len). A new election MUST follow.

pub fn contains(&self, member_id: &[u8]) -> bool

pub fn members(&self) -> &[Vec<u8>]

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn config(&self) -> &StewardListConfig

pub fn election_epoch(&self) -> u64

pub fn retry_round(&self) -> u32

Historical tag — the retry-round seed that was fed into the SHA256 sort when this list was accepted. Joiners carry this value in ConversationSync so they can re-derive the same ordering.

Trait Implementations

impl Clone for StewardList

fn clone(&self) -> StewardList

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StewardList

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

Formats the value using the given formatter.

impl PartialEq for StewardList

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for StewardList

impl StructuralPartialEq for StewardList