lighthouse/eth2/state_processing/src/per_slot_processing.rs
2019-03-07 08:37:13 +11:00

59 lines
1.5 KiB
Rust

use crate::*;
use types::{BeaconState, BeaconStateError, ChainSpec, Hash256};
#[derive(Debug, PartialEq)]
pub enum Error {
BeaconStateError(BeaconStateError),
EpochProcessingError(EpochProcessingError),
}
/// Advances a state forward by one slot, performing per-epoch processing if required.
///
/// Spec v0.4.0
pub fn per_slot_processing(
state: &mut BeaconState,
previous_block_root: Hash256,
spec: &ChainSpec,
) -> Result<(), Error> {
if (state.slot + 1) % spec.slots_per_epoch == 0 {
per_epoch_processing(state, spec)?;
state.advance_caches();
}
state.slot += 1;
update_block_roots(state, previous_block_root, spec);
Ok(())
}
/// Updates the state's block roots as per-slot processing is performed.
///
/// Spec v0.4.0
pub fn update_block_roots(state: &mut BeaconState, previous_block_root: Hash256, spec: &ChainSpec) {
state.latest_block_roots[(state.slot.as_usize() - 1) % spec.latest_block_roots_length] =
previous_block_root;
if state.slot.as_usize() % spec.latest_block_roots_length == 0 {
let root = merkle_root(&state.latest_block_roots[..]);
state.batched_block_roots.push(root);
}
}
fn merkle_root(_input: &[Hash256]) -> Hash256 {
// TODO: implement correctly.
Hash256::zero()
}
impl From<BeaconStateError> for Error {
fn from(e: BeaconStateError) -> Error {
Error::BeaconStateError(e)
}
}
impl From<EpochProcessingError> for Error {
fn from(e: EpochProcessingError) -> Error {
Error::EpochProcessingError(e)
}
}