lighthouse/beacon_node/beacon_chain/src/persisted_beacon_chain.rs
Paul Hauner bd39cc8e26 Apply hotfix for inconsistent head (#1639)
## Issue Addressed

- Resolves #1616

## Proposed Changes

If we look at the function which persists fork choice and the canonical head to disk:

1db8daae0c/beacon_node/beacon_chain/src/beacon_chain.rs (L234-L280)

There is a race-condition which might cause the canonical head and fork choice values to be out-of-sync.

I believe this is the cause of #1616. I managed to recreate the issue and produce a database that was unable to sync under the `master` branch but able to sync with this branch.

These new changes solve the issue by ignoring the persisted `canonical_head_block_root` value and instead getting fork choice to generate it. This ensures that the canonical head is in-sync with fork choice.

## Additional Info

This is hotfix method that leaves some crusty code hanging around. Once this PR is merged (to satisfy the v0.2.x users) we should later update and merge #1638 so we can have a clean fix for the v0.3.x versions.
2020-09-22 02:06:10 +00:00

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951 B
Rust

use crate::head_tracker::SszHeadTracker;
use ssz::{Decode, Encode};
use ssz_derive::{Decode, Encode};
use store::{DBColumn, Error as StoreError, StoreItem};
use types::Hash256;
#[derive(Clone, Encode, Decode)]
pub struct PersistedBeaconChain {
/// This value is ignored to resolve the issue described here:
///
/// https://github.com/sigp/lighthouse/pull/1639
///
/// The following PR will clean-up and remove this field:
///
/// https://github.com/sigp/lighthouse/pull/1638
pub canonical_head_block_root: Hash256,
pub genesis_block_root: Hash256,
pub ssz_head_tracker: SszHeadTracker,
}
impl StoreItem for PersistedBeaconChain {
fn db_column() -> DBColumn {
DBColumn::BeaconChain
}
fn as_store_bytes(&self) -> Vec<u8> {
self.as_ssz_bytes()
}
fn from_store_bytes(bytes: &[u8]) -> Result<Self, StoreError> {
Self::from_ssz_bytes(bytes).map_err(Into::into)
}
}