prysm-pulse/beacon-chain/forkchoice/doubly-linked-tree/on_tick.go
Potuz fc509cc220
Prune during on_tick (#11387)
* Prune during on_tick

* add unit test

* fix tests

Co-authored-by: terencechain <terence@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2022-09-08 14:41:10 +00:00

75 lines
2.8 KiB
Go

package doublylinkedtree
import (
"context"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/v3/config/features"
types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
"github.com/prysmaticlabs/prysm/v3/time/slots"
)
// NewSlot mimics the implementation of `on_tick` in fork choice consensus spec.
// It resets the proposer boost root in fork choice, and it updates store's justified checkpoint
// if a better checkpoint on the store's finalized checkpoint chain.
// This should only be called at the start of every slot interval.
//
// Spec pseudocode definition:
// # Reset store.proposer_boost_root if this is a new slot
// if current_slot > previous_slot:
// store.proposer_boost_root = Root()
//
// # Not a new epoch, return
// if not (current_slot > previous_slot and compute_slots_since_epoch_start(current_slot) == 0):
// return
//
// # Update store.justified_checkpoint if a better checkpoint on the store.finalized_checkpoint chain
// if store.best_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
// finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
// ancestor_at_finalized_slot = get_ancestor(store, store.best_justified_checkpoint.root, finalized_slot)
// if ancestor_at_finalized_slot == store.finalized_checkpoint.root:
// store.justified_checkpoint = store.best_justified_checkpoint
func (f *ForkChoice) NewSlot(ctx context.Context, slot types.Slot) error {
// Reset proposer boost root
if err := f.ResetBoostedProposerRoot(ctx); err != nil {
return errors.Wrap(err, "could not reset boosted proposer root in fork choice")
}
// Return if it's not a new epoch.
if !slots.IsEpochStart(slot) {
return nil
}
// Update store.justified_checkpoint if a better checkpoint on the store.finalized_checkpoint chain
f.store.checkpointsLock.RLock()
bjcp := f.store.bestJustifiedCheckpoint
jcp := f.store.justifiedCheckpoint
fcp := f.store.finalizedCheckpoint
f.store.checkpointsLock.RUnlock()
if bjcp.Epoch > jcp.Epoch {
finalizedSlot, err := slots.EpochStart(fcp.Epoch)
if err != nil {
return err
}
// We check that the best justified checkpoint is a descendant of the finalized checkpoint.
// This should always happen as forkchoice enforces that every node is a descendant of the
// finalized checkpoint. This check is here for additional security, consider removing the extra
// loop call here.
r, err := f.AncestorRoot(ctx, bjcp.Root, finalizedSlot)
if err != nil {
return err
}
if r == fcp.Root {
f.store.checkpointsLock.Lock()
f.store.prevJustifiedCheckpoint = jcp
f.store.justifiedCheckpoint = bjcp
f.store.checkpointsLock.Unlock()
}
}
if !features.Get().DisablePullTips {
f.updateUnrealizedCheckpoints()
}
return f.store.prune(ctx)
}