prysm-pulse/beacon-chain/core/helpers/block.go
Victor Farazdagi b577869ed6
Fixes import aliases (#8497)
* Fixes import aliases

* another fix

* reset gw files

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2021-02-22 23:20:57 +00:00

73 lines
2.7 KiB
Go

package helpers
import (
"math"
"github.com/pkg/errors"
types "github.com/prysmaticlabs/eth2-types"
ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
stateTrie "github.com/prysmaticlabs/prysm/beacon-chain/state"
"github.com/prysmaticlabs/prysm/shared/params"
)
// VerifyNilBeaconBlock checks if any composite field of input signed beacon block is nil.
// Access to these nil fields will result in run time panic,
// it is recommended to run these checks as first line of defense.
func VerifyNilBeaconBlock(b *ethpb.SignedBeaconBlock) error {
if b == nil {
return errors.New("signed beacon block can't be nil")
}
if b.Block == nil {
return errors.New("beacon block can't be nil")
}
if b.Block.Body == nil {
return errors.New("beacon block body can't be nil")
}
return nil
}
// BlockRootAtSlot returns the block root stored in the BeaconState for a recent slot.
// It returns an error if the requested block root is not within the slot range.
//
// Spec pseudocode definition:
// def get_block_root_at_slot(state: BeaconState, slot: Slot) -> Hash:
// """
// Return the block root at a recent ``slot``.
// """
// assert slot < state.slot <= slot + SLOTS_PER_HISTORICAL_ROOT
// return state.block_roots[slot % SLOTS_PER_HISTORICAL_ROOT]
func BlockRootAtSlot(state *stateTrie.BeaconState, slot types.Slot) ([]byte, error) {
if math.MaxUint64-slot < params.BeaconConfig().SlotsPerHistoricalRoot {
return []byte{}, errors.New("slot overflows uint64")
}
if slot >= state.Slot() || state.Slot() > slot+params.BeaconConfig().SlotsPerHistoricalRoot {
return []byte{}, errors.Errorf("slot %d out of bounds", slot)
}
return state.BlockRootAtIndex(uint64(slot % params.BeaconConfig().SlotsPerHistoricalRoot))
}
// StateRootAtSlot returns the cached state root at that particular slot. If no state
// root has been cached it will return a zero-hash.
func StateRootAtSlot(state *stateTrie.BeaconState, slot types.Slot) ([]byte, error) {
if slot >= state.Slot() || state.Slot() > slot+params.BeaconConfig().SlotsPerHistoricalRoot {
return []byte{}, errors.Errorf("slot %d out of bounds", slot)
}
return state.StateRootAtIndex(uint64(slot % params.BeaconConfig().SlotsPerHistoricalRoot))
}
// BlockRoot returns the block root stored in the BeaconState for epoch start slot.
//
// Spec pseudocode definition:
// def get_block_root(state: BeaconState, epoch: Epoch) -> Hash:
// """
// Return the block root at the start of a recent ``epoch``.
// """
// return get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch))
func BlockRoot(state *stateTrie.BeaconState, epoch types.Epoch) ([]byte, error) {
s, err := StartSlot(epoch)
if err != nil {
return nil, err
}
return BlockRootAtSlot(state, s)
}