nimbus-eth2/research/block_sim.nim

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# beacon_chain
# Copyright (c) 2019-2020 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.
# `block_sim` is a block and attestation simulator similar to `state_sim` whose
# task is to run the beacon chain without considering the network or the
# wall clock. Functionally, it achieves the same as the distributed beacon chain
# by producing blocks and attestations as if they were created by separate
# nodes, just like a set of `beacon_node` instances would.
#
# Similar to `state_sim`, but uses the block and attestation pools along with
# a database, as if a real node was running.
import
math, stats, times, strformat,
options, random, tables, os,
confutils, chronicles, eth/db/kvstore_sqlite3,
../tests/[testblockutil],
../beacon_chain/spec/[beaconstate, crypto, datatypes, digest, presets,
helpers, validator, signatures, state_transition],
../beacon_chain/[
attestation_pool, beacon_node_types, beacon_chain_db,
validator_pool, eth1_monitor, extras],
../beacon_chain/block_pools/[
spec_cache, chain_dag, quarantine, clearance],
../beacon_chain/ssz/[merkleization, ssz_serialization],
./simutils
type Timers = enum
tBlock = "Process non-epoch slot with block"
tEpoch = "Process epoch slot with block"
tHashBlock = "Tree-hash block"
tSignBlock = "Sign block"
tAttest = "Have committee attest to block"
tReplay = "Replay all produced blocks"
proc gauss(r: var Rand; mu = 0.0; sigma = 1.0): float =
# TODO This is present in Nim 1.4
const K = sqrt(2 / E)
var
a = 0.0
b = 0.0
while true:
a = rand(r, 1.0)
b = (2.0 * rand(r, 1.0) - 1.0) * K
if b * b <= -4.0 * a * a * ln(a): break
result = mu + sigma * (b / a)
# TODO confutils is an impenetrable black box. how can a help text be added here?
cli do(slots = SLOTS_PER_EPOCH * 6,
validators = SLOTS_PER_EPOCH * 200, # One per shard is minimum
attesterRatio {.desc: "ratio of validators that attest in each round"} = 0.82,
blockRatio {.desc: "ratio of slots with blocks"} = 1.0,
replay = true):
let
(state, depositContractSnapshot) = loadGenesis(validators, false)
genesisBlock = get_initial_beacon_block(state[].data)
runtimePreset = defaultRuntimePreset
genesisTime = float state[].data.genesis_time
echo "Starting simulation..."
let db = BeaconChainDB.init(runtimePreset, "block_sim_db")
defer: db.close()
ChainDAGRef.preInit(db, state[].data, state[].data, genesisBlock)
putInitialDepositContractSnapshot(db, depositContractSnapshot)
var
chainDag = ChainDAGRef.init(runtimePreset, db)
eth1Chain = Eth1Chain.init(runtimePreset, db)
merkleizer = depositContractSnapshot.createMerkleizer
quarantine = QuarantineRef()
attPool = AttestationPool.init(chainDag, quarantine)
timers: array[Timers, RunningStat]
attesters: RunningStat
r = initRand(1)
eth1Chain.addBlock Eth1Block(
number: Eth1BlockNumber 1,
timestamp: Eth1BlockTimestamp genesisTime,
voteData: Eth1Data(
deposit_root: merkleizer.getDepositsRoot,
deposit_count: merkleizer.getChunkCount))
let replayState = assignClone(chainDag.headState)
proc handleAttestations(slot: Slot) =
let
attestationHead = chainDag.head.atSlot(slot)
chainDag.withState(chainDag.tmpState, attestationHead):
let committees_per_slot =
get_committee_count_per_slot(state, slot.epoch, cache)
for committee_index in 0'u64..<committees_per_slot:
let committee = get_beacon_committee(
state, slot, committee_index.CommitteeIndex, cache)
for index_in_committee, validatorIdx in committee:
if rand(r, 1.0) <= attesterRatio:
let
data = makeAttestationData(
state, slot, committee_index.CommitteeIndex, blck.root)
sig =
get_attestation_signature(state.fork,
state.genesis_validators_root,
data, hackPrivKey(state.validators[validatorIdx]))
var aggregation_bits = CommitteeValidatorsBits.init(committee.len)
aggregation_bits.setBit index_in_committee
attPool.addAttestation(
Attestation(
data: data,
aggregation_bits: aggregation_bits,
signature: sig
), [validatorIdx].toHashSet(), data.slot)
proc proposeBlock(slot: Slot) =
if rand(r, 1.0) > blockRatio:
return
let
head = chainDag.head
chainDag.withState(chainDag.tmpState, head.atSlot(slot)):
let
finalizedEpochRef = chainDag.getFinalizedEpochRef()
proposerIdx = get_beacon_proposer_index(state, cache).get()
privKey = hackPrivKey(state.validators[proposerIdx])
eth1ProposalData = eth1Chain.getBlockProposalData(
state,
finalizedEpochRef.eth1_data,
finalizedEpochRef.eth1_deposit_index)
message = makeBeaconBlock(
runtimePreset,
hashedState,
proposerIdx,
head.root,
privKey.genRandaoReveal(state.fork, state.genesis_validators_root, slot),
eth1ProposalData.vote,
default(GraffitiBytes),
attPool.getAttestationsForBlock(state, cache),
eth1ProposalData.deposits,
@[],
@[],
@[],
noRollback,
cache)
var
newBlock = SignedBeaconBlock(
message: message.get()
)
let blockRoot = withTimerRet(timers[tHashBlock]):
hash_tree_root(newBlock.message)
newBlock.root = blockRoot
# Careful, state no longer valid after here because of the await..
newBlock.signature = withTimerRet(timers[tSignBlock]):
get_block_signature(
state.fork, state.genesis_validators_root, newBlock.message.slot,
blockRoot, privKey)
let added = chainDag.addRawBlock(quarantine, newBlock) do (
blckRef: BlockRef, signedBlock: SignedBeaconBlock,
epochRef: EpochRef, state: HashedBeaconState):
# Callback add to fork choice if valid
attPool.addForkChoice(epochRef, blckRef, signedBlock.message, blckRef.slot)
blck() = added[]
chainDag.updateHead(added[], quarantine)
var
lastEth1BlockAt = genesisTime
eth1BlockNum = 1000
for i in 0..<slots:
let
slot = Slot(i + 1)
t =
if slot.isEpoch: tEpoch
else: tBlock
now = genesisTime + float(slot * SECONDS_PER_SLOT)
while true:
let nextBlockTime = lastEth1BlockAt +
max(1.0, gauss(r, float SECONDS_PER_ETH1_BLOCK, 3.0))
if nextBlockTime > now:
break
inc eth1BlockNum
var eth1Block = Eth1Block(
number: Eth1BlockNumber eth1BlockNum,
timestamp: Eth1BlockTimestamp nextBlockTime,
voteData: Eth1Data(
block_hash: makeFakeHash(eth1BlockNum)))
let newDeposits = int clamp(gauss(r, 5.0, 8.0), 0.0, 1000.0)
for i in 0 ..< newDeposits:
let d = makeDeposit(merkleizer.getChunkCount.int, {skipBLSValidation})
eth1Block.deposits.add d
merkleizer.addChunk hash_tree_root(d).data
eth1Block.voteData.deposit_root = merkleizer.getDepositsRoot
eth1Block.voteData.deposit_count = merkleizer.getChunkCount
eth1Chain.addBlock eth1Block
lastEth1BlockAt = nextBlockTime
if blockRatio > 0.0:
withTimer(timers[t]):
proposeBlock(slot)
if attesterRatio > 0.0:
withTimer(timers[tAttest]):
handleAttestations(slot)
# TODO if attestation pool was smarter, it would include older attestations
# too!
verifyConsensus(chainDag.headState.data.data, attesterRatio * blockRatio)
if t == tEpoch:
echo &". slot: {shortLog(slot)} ",
&"epoch: {shortLog(slot.compute_epoch_at_slot)}"
else:
write(stdout, ".")
flushFile(stdout)
if replay:
withTimer(timers[tReplay]):
var cache = StateCache()
chainDag.updateStateData(
replayState[], chainDag.head.atSlot(Slot(slots)), false, cache)
echo "Done!"
printTimers(chainDag.headState.data.data, attesters, true, timers)