Struct EpochCache 

pub struct EpochCache { /* private fields */ }

Available on crate feature unstable only.

A cache of validator committees indexed by epoch.

The cache always knows about the current committee (the one in effect at the network’s most recently observed epoch) and remembers each completed epoch’s committee. Lookups via Self::committee_for_epoch return the committee that was active during the requested epoch, or None if the epoch falls outside the half-open range [start_epoch, current_epoch].

The cache is advanced by calling Self::apply_ratchet_update with the committee that takes effect for the next epoch. The driver in super::ratchet is responsible for fetching and BLS-verifying the end-of-epoch summaries that feed these updates.

Committees are stored behind Arc so lookups don’t have to clone the (potentially ~100-member) committee body. Callers receive an Arc<ValidatorCommittee> they can clone cheaply.

Implementations

impl EpochCache

pub fn new(starting_committee: ValidatorCommittee) -> Self

Build a fresh cache seeded with starting_committee.

starting_committee.epoch becomes the cache’s starting epoch and the committee is treated as covering that epoch onwards until the first ratchet update is applied. The starting epoch need not be zero — clients that bootstrap from a bundled trust anchor or resume from a known checkpoint may seed the cache partway through the chain.

pub fn current_committee(&self) -> &ValidatorCommittee

The committee in effect for the current epoch.

pub fn current_epoch(&self) -> u64

The epoch number the cache is currently tracking.

pub fn starting_epoch(&self) -> u64

The earliest epoch the cache has a committee for.

pub fn committee_for_epoch(&self, epoch: u64) -> Option<Arc<ValidatorCommittee>>

Look up the validator committee that was in effect during epoch.

Returns None if epoch falls outside the range the cache knows about — either before Self::starting_epoch or strictly after Self::current_epoch.

pub fn apply_ratchet_update( &mut self, new_committee: ValidatorCommittee, ) -> Result<(), LightClientError>

Advance the cache: move the current epoch into completed_committees and install new_committee as the new current epoch.

new_committee.epoch must be exactly one greater than the cache’s current epoch.

Trait Implementations

impl Clone for EpochCache

fn clone(&self) -> EpochCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EpochCache

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

Formats the value using the given formatter.