Struct ClosedTimestampTracker 

pub struct ClosedTimestampTracker { /* private fields */ }

Tracks the most recent apply instant per Raft group plus the shared node-wide HLC.

Implementations

impl ClosedTimestampTracker

pub fn new() -> Self

Construct a tracker with a fresh, node-private HLC. Tests and stand-alone follower-read setups use this; production paths should call Self::with_hlc to share the node-wide clock.

pub fn with_hlc(hlc: Arc<HlcClock>) -> Self

Construct a tracker wired to a caller-supplied HLC. Use this in production so the tracker’s fold_remote_hlc advances the same clock that other subsystems read via now().

pub fn hlc(&self) -> &Arc<HlcClock>

Read access to the shared HLC. Other apply-side subsystems (descriptor leases, metadata cache) advance and read it through this handle.

pub fn mark_applied(&self, group_id: u64)

Record that group_id just applied one or more entries. Called by the raft-loop applier after each apply batch.

pub fn mark_applied_at(&self, group_id: u64, at: Instant)

Record that group_id just applied, using a caller-supplied instant. Exposed for deterministic testing with paused time.

pub fn fold_remote_hlc(&self, group_id: u64, remote: Hlc) -> Hlc

Mark a group applied AND fold the leader-stamped remote HLC into the local clock. Returns the merged HLC that any local stamp emitted after this call is guaranteed to be strictly greater than.

This is the production apply-path entry point: every committed entry that carries a leader HLC (descriptor leases, catalog DDL, drain events) should route through here so cross-node _ts_system skew is bounded at this node.

pub fn is_fresh_enough(&self, group_id: u64, max_staleness: Duration) -> bool

Check whether this node’s replica of group_id has applied recently enough that a read with max_staleness can be served locally.

Returns false if the group has never applied on this node (no closed timestamp recorded).

pub fn staleness(&self, group_id: u64) -> Option<Duration>

Return the age of the closed timestamp for a group, or None if the group has never applied on this node. Useful for observability (metrics, SHOW commands).

Trait Implementations

impl Default for ClosedTimestampTracker

fn default() -> Self

Returns the “default value” for a type.