Struct StabilityMonitor 

pub struct StabilityMonitor {
    replica_id: String,
    peer_frontiers: HashMap<String, VersionVector>,
    peer_heads: HashMap<String, Vec<Hash>>,
    last_update: HashMap<String, u64>,
    local_frontier: VersionVector,
    local_heads: Vec<Hash>,
    stable_frontier: VersionVector,
    config: StabilityConfig,
}

Monitors stability across replicas for safe compaction decisions.

Stability is achieved when an update has been delivered to all tracked peers. Only stable updates can be safely compacted.

Fields

replica_id: String

Our replica ID.

peer_frontiers: HashMap<String, VersionVector>

Known peer frontiers (version vectors).

peer_heads: HashMap<String, Vec<Hash>>

Known peer heads (DAG heads).

last_update: HashMap<String, u64>

Timestamp of last update from each peer.

local_frontier: VersionVector

Our current version vector.

local_heads: Vec<Hash>

Our current DAG heads.

stable_frontier: VersionVector

The computed stable frontier (min of all known frontiers).

config: StabilityConfig

Configuration.

Implementations

impl StabilityMonitor

pub fn new(replica_id: impl Into<String>) -> Self

Create a new stability monitor.

pub fn with_config( replica_id: impl Into<String>, config: StabilityConfig, ) -> Self

Create with custom configuration.

pub fn replica_id(&self) -> &str

Get our replica ID.

pub fn update_local_frontier(&mut self, vv: VersionVector, heads: Vec<Hash>)

Update our local frontier.

pub fn update_peer_frontier(&mut self, update: FrontierUpdate)

Update a peer’s frontier.

pub fn remove_peer(&mut self, peer_id: &str)

Remove a peer from tracking.

pub fn tracked_peers(&self) -> Vec<&String>

Get the list of tracked peers.

pub fn peer_count(&self) -> usize

Get the number of tracked peers.

pub fn peer_frontier(&self, peer_id: &str) -> Option<&VersionVector>

Get a peer’s frontier.

pub fn stable_frontier(&self) -> &VersionVector

Get the stable frontier.

pub fn local_frontier(&self) -> &VersionVector

Get the local frontier.

pub fn is_operation_stable(&self, replica_id: &str, sequence: u64) -> bool

Check if a specific operation is stable.

pub fn is_stable(&self, vv: &VersionVector) -> bool

Check if a version vector is fully stable.

pub fn stability_state(&self, vv: &VersionVector) -> StabilityState

Get the stability state for a version vector.

pub fn has_quorum(&self) -> bool

Check if we have enough peers for meaningful stability.

pub fn stale_peers(&self, current_time: u64) -> Vec<String>

Get stale peers (those with old frontier updates).

pub fn gc_stale_peers(&mut self, current_time: u64)

Remove stale peers.

fn recompute_stable_frontier(&mut self)

Recompute the stable frontier.

pub fn stats(&self) -> StabilityStats

Get statistics about stability.

pub fn create_frontier_update(&self, timestamp: u64) -> FrontierUpdate

Create a frontier update message for broadcasting.