Struct Membership 

pub struct Membership {
    pub epoch: u64,
    pub members: Vec<ReplicaId>,
    pub entry: Option<Entry>,
    pub previous: Vec<ReplicaId>,
}

The members of one epoch.

Membership change. Membership is fixed within an epoch. A change is a log entry (a reconfiguration body naming the next epoch’s members and addresses) that the primary proposes as the last entry of its epoch: it proposes nothing after it. Once that entry commits, every member of the new configuration that holds the log through it changes to the new epoch’s first view by an ordinary view change among the new members; members not in it retire; new members fetch the epoch and the log from the members, and take part in no view change until they hold the log through the entry. A change requires that a quorum of the new members are members now (so a quorum of the new epoch starts with the whole committed log): one step can add or remove members, or replace a minority, but not replace a majority.

Fields

epoch: u64

members: Vec<ReplicaId>

In order: the primary of the epoch’s view v is members[(v - first_view(epoch)) % len].

entry: Option<Entry>

The committed reconfiguration entry that began this epoch (none for epoch 0).

previous: Vec<ReplicaId>

The members this replica knew before (they hold the committed log through entry and serve it to members catching up into the epoch).

Implementations

impl Membership

pub fn initial(n: u8) -> Self

pub fn from_entry(e: &Entry) -> Option<Self>

From a committed reconfiguration entry.

pub fn addresses(&self) -> Vec<(ReplicaId, String)>

Every member’s address, as the reconfiguration entry names them (empty for epoch 0, whose addresses the host configures).

pub fn start(&self) -> Op

The op of the entry that began this epoch.

pub fn contains(&self, id: ReplicaId) -> bool

pub fn quorum(&self) -> usize

pub fn primary_of(&self, view: u64) -> ReplicaId

pub fn next( &self, primary: ReplicaId, members: &[(ReplicaId, String)], ) -> Result<Vec<(ReplicaId, String)>, &'static str>

Checks a requested membership for the next epoch and orders it: the current primary first if it stays (it then leads the new epoch’s first view), the other current members next, new members last.

Trait Implementations

impl Clone for Membership

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 Membership

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

Formats the value using the given formatter.

impl Eq for Membership

impl PartialEq for Membership

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Membership