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

36 lines
1.2 KiB
Rust

use safe_arith::SafeArith;
use types::{BeaconStateError as Error, *};
/// Process slashings.
///
/// Spec v0.12.1
pub fn process_slashings<T: EthSpec>(
state: &mut BeaconState<T>,
total_balance: u64,
spec: &ChainSpec,
) -> Result<(), Error> {
let epoch = state.current_epoch();
let sum_slashings = state.get_all_slashings().iter().sum::<u64>();
for (index, validator) in state.validators.iter().enumerate() {
if validator.slashed
&& epoch + T::EpochsPerSlashingsVector::to_u64().safe_div(2)?
== validator.withdrawable_epoch
{
let increment = spec.effective_balance_increment;
let penalty_numerator = validator
.effective_balance
.safe_div(increment)?
.safe_mul(std::cmp::min(sum_slashings.safe_mul(3)?, total_balance))?;
let penalty = penalty_numerator
.safe_div(total_balance)?
.safe_mul(increment)?;
// Equivalent to `decrease_balance(state, index, penalty)`, but avoids borrowing `state`.
state.balances[index] = state.balances[index].saturating_sub(penalty);
}
}
Ok(())
}