lighthouse/consensus/state_processing/src/per_slot_processing.rs
blacktemplar 23a8f31f83 Fix clippy warnings (#1385)
## Issue Addressed

NA

## Proposed Changes

Fixes most clippy warnings and ignores the rest of them, see issue #1388.
2020-07-23 14:18:00 +00:00

82 lines
2.3 KiB
Rust

use crate::{per_epoch_processing::EpochProcessingSummary, *};
use types::*;
#[derive(Debug, PartialEq)]
pub enum Error {
BeaconStateError(BeaconStateError),
EpochProcessingError(EpochProcessingError),
}
/// Advances a state forward by one slot, performing per-epoch processing if required.
///
/// If the root of the supplied `state` is known, then it can be passed as `state_root`. If
/// `state_root` is `None`, the root of `state` will be computed using a cached tree hash.
/// Providing the `state_root` makes this function several orders of magniude faster.
///
/// Spec v0.12.1
pub fn per_slot_processing<T: EthSpec>(
state: &mut BeaconState<T>,
state_root: Option<Hash256>,
spec: &ChainSpec,
) -> Result<Option<EpochProcessingSummary>, Error> {
cache_state(state, state_root)?;
let summary = if state.slot > spec.genesis_slot && (state.slot + 1) % T::slots_per_epoch() == 0
{
Some(per_epoch_processing(state, spec)?)
} else {
None
};
state.slot += 1;
Ok(summary)
}
fn cache_state<T: EthSpec>(
state: &mut BeaconState<T>,
state_root: Option<Hash256>,
) -> Result<(), Error> {
let previous_state_root = if let Some(root) = state_root {
root
} else {
state.update_tree_hash_cache()?
};
// Note: increment the state slot here to allow use of our `state_root` and `block_root`
// getter/setter functions.
//
// This is a bit hacky, however it gets the job safely without lots of code.
let previous_slot = state.slot;
state.slot += 1;
// Store the previous slot's post state transition root.
state.set_state_root(previous_slot, previous_state_root)?;
// Cache latest block header state root
if state.latest_block_header.state_root == Hash256::zero() {
state.latest_block_header.state_root = previous_state_root;
}
// Cache block root
let latest_block_root = state.latest_block_header.canonical_root();
state.set_block_root(previous_slot, latest_block_root)?;
// Set the state slot back to what it should be.
state.slot -= 1;
Ok(())
}
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)
}
}