Struct LeaderState 

pub struct LeaderState {
    pub ballot: u64,
    pub leader_id: String,
    pub priority: i32,
    pub lease_expiry_nanos: u64,
    pub versionstamp: [u8; 12],
}

The core leader state - stored at a single key

Contains all information needed to determine leadership without scanning candidates.

Ballot Numbers

The ballot number works like Raft’s term:

• Monotonically increasing counter
• Higher ballot always wins
• Prevents split-brain after recovery/partition
• Incremented on every leadership claim or refresh

Fields

ballot: u64

Ballot number (like Raft’s term)

Always increments when claiming or refreshing leadership. Higher ballot wins in any conflict.

leader_id: String

Unique identifier of the leader process

priority: i32

Leader’s priority (higher = more preferred)

Used for preemption decisions when allow_preemption is enabled.

lease_expiry_nanos: u64

Absolute timestamp when lease expires (nanos since epoch)

Leadership is only valid while current_time < lease_expiry_nanos.

versionstamp: [u8; 12]

Versionstamp assigned when this process registered

Used for identity consistency and ordering.

Implementations

impl LeaderState

pub fn is_lease_valid(&self, current_time: Duration) -> bool

Check if the lease is still valid

Arguments

• current_time - Current time as Duration since epoch

Returns

true if the lease has not expired

pub fn remaining_lease(&self, current_time: Duration) -> Option<Duration>

Get remaining lease duration, if any

Arguments

• current_time - Current time as Duration since epoch

Returns

Some(Duration) if lease is still valid, None if expired

Trait Implementations

impl Clone for LeaderState

fn clone(&self) -> LeaderState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LeaderState

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

Formats the value using the given formatter.

impl PartialEq for LeaderState

fn eq(&self, other: &LeaderState) -> 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 LeaderState

impl StructuralPartialEq for LeaderState