lighthouse/consensus/state_processing/src/per_epoch_processing/registry_updates.rs
2020-06-19 11:18:27 +10:00

61 lines
2.3 KiB
Rust

use super::super::common::initiate_validator_exit;
use super::Error;
use itertools::Itertools;
use types::*;
/// Performs a validator registry update, if required.
///
/// Spec v0.12.1
pub fn process_registry_updates<T: EthSpec>(
state: &mut BeaconState<T>,
spec: &ChainSpec,
) -> Result<(), Error> {
// Process activation eligibility and ejections.
// Collect eligible and exiting validators (we need to avoid mutating the state while iterating).
// We assume it's safe to re-order the change in eligibility and `initiate_validator_exit`.
// Rest assured exiting validators will still be exited in the same order as in the spec.
let current_epoch = state.current_epoch();
let is_ejectable = |validator: &Validator| {
validator.is_active_at(current_epoch)
&& validator.effective_balance <= spec.ejection_balance
};
let indices_to_update: Vec<_> = state
.validators
.iter()
.enumerate()
.filter(|(_, validator)| {
validator.is_eligible_for_activation_queue(spec) || is_ejectable(validator)
})
.map(|(idx, _)| idx)
.collect();
for index in indices_to_update {
if state.validators[index].is_eligible_for_activation_queue(spec) {
state.validators[index].activation_eligibility_epoch = current_epoch + 1;
}
if is_ejectable(&state.validators[index]) {
initiate_validator_exit(state, index, spec)?;
}
}
// Queue validators eligible for activation and not dequeued for activation prior to finalized epoch
let activation_queue = state
.validators
.iter()
.enumerate()
.filter(|(_, validator)| validator.is_eligible_for_activation(state, spec))
.sorted_by_key(|(index, validator)| (validator.activation_eligibility_epoch, *index))
.map(|(index, _)| index)
.collect_vec();
// Dequeue validators for activation up to churn limit
let churn_limit = state.get_churn_limit(spec)? as usize;
let delayed_activation_epoch = state.compute_activation_exit_epoch(current_epoch, spec);
for index in activation_queue.into_iter().take(churn_limit) {
let validator = &mut state.validators[index];
validator.activation_epoch = delayed_activation_epoch;
}
Ok(())
}