nimbus-eth2/tests/spec_epoch_processing/justification_finalization_...

107 lines
4.2 KiB
Nim

# beacon_chain
# 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.
import
# Standard library
strformat,
# Specs
../../beacon_chain/spec/[datatypes, state_transition_epoch, validator, helpers],
# Internals
../../beacon_chain/[state_transition],
# Test helpers
../helpers/digest_helpers
# Justification and finalization utils
# ---------------------------------------------------------------
iterator getShardsForSlot(state: BeaconState, slot: Slot): Shard =
let
epoch = compute_epoch_of_slot(slot)
epoch_start_shard = get_start_shard(state, epoch)
committees_per_slot = get_committee_count(state, epoch) div SLOTS_PER_EPOCH
shard = epoch_start_shard + committees_per_slot * (slot mod SLOTS_PER_EPOCH)
for i in 0 ..< committees_per_slot.int:
yield shard + Shard(i)
proc addMockAttestations*(
state: var BeaconState, epoch: Epoch,
source, target: Checkpoint,
sufficient_support = false
) =
# We must be at the end of the epoch
doAssert (state.slot + 1) mod SLOTS_PER_EPOCH == 0
# Alias the attestations container
var attestations: ptr seq[PendingAttestation]
if state.get_current_epoch() == epoch:
attestations = state.current_epoch_attestations.addr
elif state.get_previous_epoch() == epoch:
attestations = state.previous_epoch_attestations.addr
else:
raise newException(ValueError, &"Cannot include attestations from epoch {state.get_current_epoch()} in epoch {epoch}")
# TODO: Working with an unsigned Gwei balance is a recipe for underflows to happen
var remaining_balance = state.get_total_active_balance().int64 * 2 div 3
let start_slot = compute_start_slot_of_epoch(epoch)
# for-loop of distinct type is broken: https://github.com/nim-lang/Nim/issues/12074
for slot in start_slot.uint64 ..< start_slot.uint64 + SLOTS_PER_EPOCH:
for shard in getShardsForSlot(state, slot.Slot):
# TODO: can we move cache out of the loops
var cache = get_empty_per_epoch_cache()
let committee = get_crosslink_committee(
state, slot.Slot.compute_epoch_of_slot(),
shard, cache
)
# Create a bitfield filled with the given count per attestation,
# exactly on the right-most part of the committee field.
var aggregation_bits = init(CommitteeValidatorsBits, committee.len)
for v in 0 ..< committee.len * 2 div 3 + 1:
if remaining_balance > 0:
# Beware of the underflows, use int
remaining_balance -= state.validators[v].effective_balance.int64
aggregation_bits[v] = true
else:
break
# Remove just one attester to make the marginal support insufficient
if not sufficient_support:
# Find the first attester if any
let idx = aggregation_bits.find(true)
if idx != -1:
aggregation_bits[idx] = false
attestations[].add PendingAttestation(
aggregation_bits: aggregation_bits,
data: AttestationData(
beacon_block_root: [byte 0xFF] * 32, # Irrelevant for testing
source: source,
target: target,
crosslink: Crosslink(shard: shard)
),
inclusion_delay: 1
)
proc getCheckpoints*(epoch: Epoch): tuple[c1, c2, c3, c4, c5: Checkpoint] =
if epoch >= 1: result.c1 = Checkpoint(epoch: epoch - 1, root: [byte 0xAA] * 32)
if epoch >= 2: result.c2 = Checkpoint(epoch: epoch - 2, root: [byte 0xBB] * 32)
if epoch >= 3: result.c3 = Checkpoint(epoch: epoch - 3, root: [byte 0xCC] * 32)
if epoch >= 4: result.c4 = Checkpoint(epoch: epoch - 4, root: [byte 0xDD] * 32)
if epoch >= 5: result.c5 = Checkpoint(epoch: epoch - 5, root: [byte 0xEE] * 32)
proc putCheckpointsInBlockRoots*(
state: var BeaconState,
checkpoints: openarray[Checkpoint]) =
for c in checkpoints:
let idx = c.epoch.compute_start_slot_of_epoch() mod SLOTS_PER_HISTORICAL_ROOT
state.block_roots[idx] = c.root