nimbus-eth2/research/state_sim.nim

171 lines
6.1 KiB
Nim

# beacon_chain
# Copyright (c) 2019-2021 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
# `state_sim` runs the state transition function in isolation, creating blocks
# and attesting to them as if the network was running as a whole.
import
confutils, stats, times,
strformat,
options, sequtils, random, tables,
../tests/testblockutil,
../beacon_chain/spec/datatypes/phase0,
../beacon_chain/spec/eth2_apis/eth2_rest_serialization,
../beacon_chain/spec/[beaconstate, forks, helpers],
./simutils
type Timers = enum
tBlock = "Process non-epoch slot with block"
tEpoch = "Process epoch slot with block"
tHashBlock = "Tree-hash block"
tShuffle = "Retrieve committee once using get_beacon_committee"
tAttest = "Combine committee attestations"
func jsonName(prefix, slot: auto): string =
fmt"{prefix:04}-{shortLog(slot):08}.json"
proc writeJson*(fn, v: auto) =
var f: File
defer: close(f)
RestJson.saveFile(fn, v, pretty = true)
cli do(slots = SLOTS_PER_EPOCH * 5,
validators = SLOTS_PER_EPOCH * 400, # One per shard is minimum
json_interval = SLOTS_PER_EPOCH,
write_last_json = false,
prefix: int = 0,
attesterRatio {.desc: "ratio of validators that attest in each round"} = 0.82,
validate = true):
let
flags = if validate: {} else: {skipBlsValidation}
(state, _) = loadGenesis(validators, validate)
genesisBlock = get_initial_beacon_block(state[])
echo "Starting simulation..."
var
attestations = initTable[Slot, seq[Attestation]]()
latest_block_root = withBlck(genesisBlock): blck.root
timers: array[Timers, RunningStat]
attesters: RunningStat
r = initRand(1)
signedBlock: ForkedSignedBeaconBlock
cache = StateCache()
proc maybeWrite(last: bool) =
if write_last_json:
if getStateField(state[], slot) mod json_interval.uint64 == 0:
write(stdout, ":")
else:
write(stdout, ".")
if last:
withState(state[]): writeJson("state.json", state.data)
else:
withState(state[]):
if state.data.slot mod json_interval.uint64 == 0:
writeJson(jsonName(prefix, state.data.slot), state.data)
write(stdout, ":")
else:
write(stdout, ".")
# TODO doAssert against this up-front
# indexed attestation: validator index beyond max validators per committee
# len(indices) <= MAX_VALIDATORS_PER_COMMITTEE
for i in 0..<slots:
maybeWrite(false)
verifyConsensus(state[].phase0Data.data, attesterRatio)
let
attestations_idx = getStateField(state[], slot)
blockAttestations = attestations.getOrDefault(attestations_idx)
attestations.del attestations_idx
doAssert attestations.lenu64 <=
SLOTS_PER_EPOCH + MIN_ATTESTATION_INCLUSION_DELAY
let t =
if (getStateField(state[], slot) > GENESIS_SLOT and
(getStateField(state[], slot) + 1).isEpoch): tEpoch
else: tBlock
withTimer(timers[t]):
signedBlock = addTestBlock(
state[], latest_block_root, cache, attestations = blockAttestations,
flags = flags)
latest_block_root = withTimerRet(timers[tHashBlock]):
withBlck(signedBlock): hash_tree_root(blck.message)
if attesterRatio > 0.0:
# attesterRatio is the fraction of attesters that actually do their
# work for every slot - we'll randomize it deterministically to give
# some variation
let
target_slot = getStateField(state[], slot) + MIN_ATTESTATION_INCLUSION_DELAY - 1
committees_per_slot =
get_committee_count_per_slot(state[], target_slot.epoch, cache)
let
scass = withTimerRet(timers[tShuffle]):
mapIt(
0 ..< committees_per_slot.int,
get_beacon_committee(state[], target_slot, it.CommitteeIndex, cache))
for i, scas in scass:
var
attestation: Attestation
first = true
attesters.push scas.len()
withTimer(timers[tAttest]):
var agg {.noInit.}: AggregateSignature
for v in scas:
if (rand(r, high(int)).float * attesterRatio).int <= high(int):
if first:
attestation =
makeAttestation(state[], latest_block_root, scas, target_slot,
i.CommitteeIndex, v, cache, flags)
agg.init(attestation.signature.load.get())
first = false
else:
let att2 =
makeAttestation(state[], latest_block_root, scas, target_slot,
i.CommitteeIndex, v, cache, flags)
if not att2.aggregation_bits.overlaps(attestation.aggregation_bits):
attestation.aggregation_bits.incl(att2.aggregation_bits)
if skipBlsValidation notin flags:
agg.aggregate(att2.signature.load.get())
attestation.signature = agg.finish().toValidatorSig()
if not first:
# add the attestation if any of the validators attested, as given
# by the randomness. We have to delay when the attestation is
# actually added to the block per the attestation delay rule!
let target_slot =
attestation.data.slot + MIN_ATTESTATION_INCLUSION_DELAY - 1
doAssert target_slot > attestations_idx
var target_slot_attestations =
getOrDefault(attestations, target_slot)
target_slot_attestations.add attestation
attestations[target_slot] = target_slot_attestations
flushFile(stdout)
if getStateField(state[], slot).isEpoch:
echo &" slot: {shortLog(getStateField(state[], slot))} ",
&"epoch: {shortLog(state[].get_current_epoch())}"
maybeWrite(true) # catch that last state as well..
echo "Done!"
printTimers(state[], attesters, validate, timers)