nimbus-eth2/beacon_chain/spec/validator.nim

78 lines
3.1 KiB
Nim

# Copyright (c) 2018 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
# Helpers and functions pertaining to managing the validator set
import
options, nimcrypto, sequtils, math,
eth_common,
../ssz,
./crypto, ./datatypes, ./digest, ./helpers
func min_empty_validator_index*(
validators: seq[Validator],
validator_balances: seq[uint64],
current_slot: uint64): Option[int] =
for i, v in validators:
if validator_balances[i] == 0 and
v.latest_status_change_slot +
ZERO_BALANCE_VALIDATOR_TTL.uint64 <= current_slot:
return some(i)
func get_shuffling*(seed: Eth2Digest,
validators: openArray[Validator],
crosslinking_start_shard: uint64, # TODO remove
slot_nonaligned: uint64
): array[EPOCH_LENGTH, seq[ShardCommittee]] =
## Split up validators into groups at the start of every epoch,
## determining at what height they can make attestations and what shard they are making crosslinks for
## Implementation should do the following: http://vitalik.ca/files/ShuffleAndAssign.png
let
slot = slot_nonaligned - slot_nonaligned mod EPOCH_LENGTH
active_validator_indices = get_active_validator_indices(validators, slot)
committees_per_slot = clamp(
len(active_validator_indices) div EPOCH_LENGTH div TARGET_COMMITTEE_SIZE,
1, SHARD_COUNT div EPOCH_LENGTH).uint64
# Shuffle with seed
shuffled_active_validator_indices = shuffle(active_validator_indices, seed)
# Split the shuffled list into cycle_length pieces
validators_per_slot = split(shuffled_active_validator_indices, EPOCH_LENGTH)
assert validators_per_slot.len() == EPOCH_LENGTH # what split should do..
for slot, slot_indices in validators_per_slot:
let
shard_indices = split(slot_indices, committees_per_slot)
shard_id_start =
crosslinking_start_shard + slot.uint64 * committees_per_slot
var committees = newSeq[ShardCommittee](shard_indices.len)
for shard_position, indices in shard_indices:
committees[shard_position].shard =
shard_id_start + shard_position.uint64 mod SHARD_COUNT.uint64
committees[shard_position].committee = indices
committees[shard_position].total_validator_count =
len(active_validator_indices).uint64
result[slot] = committees
func get_new_validator_registry_delta_chain_tip*(
current_validator_registry_delta_chain_tip: Eth2Digest,
index: Uint24,
pubkey: ValidatorPubKey,
slot: uint64,
flag: ValidatorSetDeltaFlags): Eth2Digest =
## Compute the next hash in the validator registry delta hash chain.
hash_tree_root_final(ValidatorRegistryDeltaBlock(
latest_registry_delta_root: current_validator_registry_delta_chain_tip,
validator_index: index,
pubkey: pubkey,
slot: slot,
flag: flag
))