From 441ae9b58cc31f784793eb2bbfcbe3a146c48f12 Mon Sep 17 00:00:00 2001 From: Zahary Karadjov Date: Fri, 3 Jul 2020 22:29:23 +0300 Subject: [PATCH] Introduce a RuntimePreset object for the overridable testnet preset values --- beacon_chain/beacon_node.nim | 2 + beacon_chain/network_metadata.nim | 49 ++++- beacon_chain/spec/beaconstate.nim | 4 +- beacon_chain/spec/datatypes.nim | 3 +- beacon_chain/spec/helpers.nim | 2 +- beacon_chain/spec/presets/custom.nim | 199 ++++++++++-------- beacon_chain/spec/presets/v0_12_1/mainnet.nim | 7 +- beacon_chain/spec/presets/v0_12_1/minimal.nim | 7 +- beacon_chain/validator_api.nim | 6 +- 9 files changed, 166 insertions(+), 113 deletions(-) diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim index 339afcc8a..67e705784 100644 --- a/beacon_chain/beacon_node.nim +++ b/beacon_chain/beacon_node.nim @@ -1128,6 +1128,8 @@ programMain: let networkName = config.eth2Network.get metadata = case toLowerAscii(networkName) + of "mainnet": + mainnetMetadata of "altona": altonaMetadata else: diff --git a/beacon_chain/network_metadata.nim b/beacon_chain/network_metadata.nim index 03ecac037..72510d962 100644 --- a/beacon_chain/network_metadata.nim +++ b/beacon_chain/network_metadata.nim @@ -1,7 +1,8 @@ import os, strutils, - stew/byteutils, nimcrypto/hash, - eth/common/[eth_types, eth_types_json_serialization] + stew/byteutils, stew/shims/macros, nimcrypto/hash, + eth/common/[eth_types, eth_types_json_serialization], + spec/presets/custom # ATTENTION! This file will produce a large C file, because we are inlining # genesis states as C literals in the generated code (and blobs in the final @@ -29,8 +30,11 @@ type customEth2Network altona + PresetIncompatible* = object of CatchableError + Eth2NetworkMetadata* = object eth1Network*: Eth1Network + runtimePreset*: RuntimePreset # Parsing `enr.Records` is still not possible at compile-time bootstrapNodes*: seq[string] @@ -52,19 +56,60 @@ type # unknown genesis state. genesisData*: string +const presetValueLoaders = genCode(nnkBracket): + for constName in PresetValue: + let + constNameIdent = ident $constName + constType = ident getType(constName) + + yield quote do: + proc (preset: RuntimePreset, presetValue: string): bool + {.gcsafe, noSideEffect, raises: [Defect].} = + try: + when `constNameIdent` in runtimeValues: + preset.`constNameIdent` = parse(`constType`, presetValue) + true + else: + `constNameIdent` == parse(`constType`, presetValue) + except CatchableError: + false + proc loadEth2NetworkMetadata*(path: string): Eth2NetworkMetadata {.raises: [CatchableError, Defect].} = let genesisPath = path / "genesis.ssz" + config = readPresetFile(path / "config.yaml") + + var runtimePreset = RuntimePreset() + + for name, value in config.values: + if name notin runtimeValues: + if not presetValueLoaders[name](runtimePreset, value): + raise newException(PresetIncompatible, + "The preset '{path}' is not compatible with the current build due to an incompatible value {name} = {value}") Eth2NetworkMetadata( eth1Network: goerli, + runtimePreset: runtimePreset, bootstrapNodes: readFile(path / "bootstrap_nodes.txt").split("\n"), depositContractAddress: Eth1Address.fromHex readFile(path / "deposit_contract.txt").strip, depositContractDeployedAt: Eth1BlockHash.fromHex readFile(path / "deposit_contract_block.txt").strip, genesisData: if fileExists(genesisPath): readFile(genesisPath) else: "") const + mainnetMetadata* = Eth2NetworkMetadata( + eth1Network: mainnet, + runtimePreset: RuntimePreset( + MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 16384, + MIN_GENESIS_TIME: 1578009600, + GENESIS_FORK_VERSION: [byte 0, 0, 0, 0], + GENESIS_DELAY: 172800), + # TODO The values below are just placeholders for now + bootstrapNodes: @[], + depositContractAddress: "0x1234567890123456789012345678901234567890", + depositContractDeployedAt: "", + genesisData: "") + altonaMetadata* = loadEth2NetworkMetadata( currentSourcePath.parentDir / ".." / "vendor" / "eth2-testnets" / "shared" / "altona") diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim index b50a12c2d..e7c33e1ad 100644 --- a/beacon_chain/spec/beaconstate.nim +++ b/beacon_chain/spec/beaconstate.nim @@ -226,8 +226,8 @@ proc initialize_beacon_state_from_eth1*( var state = BeaconStateRef( fork: Fork( - previous_version: Version(GENESIS_FORK_VERSION), - current_version: Version(GENESIS_FORK_VERSION), + previous_version: GENESIS_FORK_VERSION, + current_version: GENESIS_FORK_VERSION, epoch: GENESIS_EPOCH), genesis_time: genesis_time_from_eth1_timestamp(eth1_timestamp), eth1_data: diff --git a/beacon_chain/spec/datatypes.nim b/beacon_chain/spec/datatypes.nim index 03dad23ba..8c6a96fd0 100644 --- a/beacon_chain/spec/datatypes.nim +++ b/beacon_chain/spec/datatypes.nim @@ -61,7 +61,7 @@ else: Epoch* = distinct uint64 import ./presets/custom - loadCustomPreset const_preset + createConstantsFromPreset const_preset const SPEC_VERSION* = "0.12.1" ## \ @@ -163,7 +163,6 @@ type data*: AttestationData signature*: TrustedSig - Version* = distinct array[4, byte] ForkDigest* = distinct array[4, byte] # https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/beacon-chain.md#forkdata diff --git a/beacon_chain/spec/helpers.nim b/beacon_chain/spec/helpers.nim index ce33dae2a..dc26a3833 100644 --- a/beacon_chain/spec/helpers.nim +++ b/beacon_chain/spec/helpers.nim @@ -158,7 +158,7 @@ func compute_fork_digest*(current_version: Version, # https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/beacon-chain.md#compute_domain func compute_domain*( domain_type: DomainType, - fork_version: Version = Version(GENESIS_FORK_VERSION), + fork_version = GENESIS_FORK_VERSION, genesis_validators_root: Eth2Digest = ZERO_HASH): Domain = # Return the domain for the ``domain_type`` and ``fork_version``. let fork_data_root = diff --git a/beacon_chain/spec/presets/custom.nim b/beacon_chain/spec/presets/custom.nim index 7571a16b7..8db43708d 100644 --- a/beacon_chain/spec/presets/custom.nim +++ b/beacon_chain/spec/presets/custom.nim @@ -1,112 +1,87 @@ import - macros, strutils, tables, + macros, strutils, parseutils, tables, stew/endians2 export toBytesBE type - BeaconChainConstants* {.pure.} = enum - BASE_REWARDS_PER_EPOCH + PresetValue* {.pure.} = enum BASE_REWARD_FACTOR BLS_WITHDRAWAL_PREFIX CHURN_LIMIT_QUOTIENT - CUSTODY_PERIOD_TO_RANDAO_PADDING DEPOSIT_CONTRACT_ADDRESS - DEPOSIT_CONTRACT_TREE_DEPTH DOMAIN_AGGREGATE_AND_PROOF DOMAIN_BEACON_ATTESTER DOMAIN_BEACON_PROPOSER - DOMAIN_CUSTODY_BIT_SLASHING DOMAIN_DEPOSIT - DOMAIN_LIGHT_CLIENT DOMAIN_RANDAO DOMAIN_SELECTION_PROOF - DOMAIN_SHARD_COMMITTEE - DOMAIN_SHARD_PROPOSAL DOMAIN_VOLUNTARY_EXIT - EARLY_DERIVED_SECRET_PENALTY_MAX_FUTURE_EPOCHS EARLY_DERIVED_SECRET_REVEAL_SLOT_REWARD_MULTIPLE EFFECTIVE_BALANCE_INCREMENT EJECTION_BALANCE - EPOCHS_PER_CUSTODY_PERIOD EPOCHS_PER_ETH1_VOTING_PERIOD EPOCHS_PER_HISTORICAL_VECTOR EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION EPOCHS_PER_SLASHINGS_VECTOR ETH1_FOLLOW_DISTANCE - GASPRICE_ADJUSTMENT_COEFFICIENT - GENESIS_EPOCH GENESIS_FORK_VERSION GENESIS_DELAY - GENESIS_SLOT HISTORICAL_ROOTS_LIMIT HYSTERESIS_DOWNWARD_MULTIPLIER HYSTERESIS_QUOTIENT HYSTERESIS_UPWARD_MULTIPLIER INACTIVITY_PENALTY_QUOTIENT - INITIAL_ACTIVE_SHARDS - JUSTIFICATION_BITS_LENGTH - LIGHT_CLIENT_COMMITTEE_PERIOD - LIGHT_CLIENT_COMMITTEE_SIZE MAX_ATTESTATIONS MAX_ATTESTER_SLASHINGS MAX_COMMITTEES_PER_SLOT - MAX_CUSTODY_KEY_REVEALS - MAX_CUSTODY_SLASHINGS MAX_DEPOSITS - MAX_EARLY_DERIVED_SECRET_REVEALS MAX_EFFECTIVE_BALANCE MAX_EPOCHS_PER_CROSSLINK - MAX_GASPRICE MAX_PROPOSER_SLASHINGS - MAX_REVEAL_LATENESS_DECREMENT MAX_SEED_LOOKAHEAD - MAX_SHARDS - MAX_SHARD_BLOCKS_PER_ATTESTATION - MAX_SHARD_BLOCK_CHUNKS MAX_VALIDATORS_PER_COMMITTEE MAX_VOLUNTARY_EXITS - MINOR_REWARD_QUOTIENT MIN_ATTESTATION_INCLUSION_DELAY MIN_DEPOSIT_AMOUNT MIN_EPOCHS_TO_INACTIVITY_PENALTY - MIN_GASPRICE MIN_GENESIS_ACTIVE_VALIDATOR_COUNT MIN_GENESIS_TIME MIN_PER_EPOCH_CHURN_LIMIT MIN_SEED_LOOKAHEAD MIN_SLASHING_PENALTY_QUOTIENT MIN_VALIDATOR_WITHDRAWABILITY_DELAY - ONLINE_PERIOD - PHASE_1_FORK_VERSION - PHASE_1_GENESIS_SLOT PROPOSER_REWARD_QUOTIENT - RANDAO_PENALTY_EPOCHS RANDOM_SUBNETS_PER_VALIDATOR SAFE_SLOTS_TO_UPDATE_JUSTIFIED - SECONDS_PER_DAY SECONDS_PER_ETH1_BLOCK SECONDS_PER_SLOT - SHARD_BLOCK_CHUNK_SIZE - SHARD_BLOCK_OFFSETS SHARD_COMMITTEE_PERIOD SHUFFLE_ROUND_COUNT SLOTS_PER_EPOCH SLOTS_PER_HISTORICAL_ROOT TARGET_AGGREGATORS_PER_COMMITTEE TARGET_COMMITTEE_SIZE - TARGET_SHARD_BLOCK_SIZE VALIDATOR_REGISTRY_LIMIT WHISTLEBLOWER_REWARD_QUOTIENT const + runtimeValues* = { + MIN_GENESIS_ACTIVE_VALIDATOR_COUNT, + MIN_GENESIS_TIME, + DEPOSIT_CONTRACT_ADDRESS, + GENESIS_FORK_VERSION, + GENESIS_DELAY, + } + # These constants cannot really be overriden in a preset. # If we encounter them, we'll just ignore the preset value. - dubiousConstants = { - # They are derived from other constants: - GENESIS_EPOCH, - SECONDS_PER_DAY, + ignoredValues = { + # The deposit contract address is loaded through a dedicated + # metadata file. It would break the property we are exploiting + # right now that all preset values can be parsed as uint64 + DEPOSIT_CONTRACT_ADDRESS # These are defined as an enum in datatypes.nim: DOMAIN_BEACON_PROPOSER, @@ -116,74 +91,116 @@ const DOMAIN_VOLUNTARY_EXIT, DOMAIN_SELECTION_PROOF, DOMAIN_AGGREGATE_AND_PROOF, - DOMAIN_SHARD_PROPOSAL, - DOMAIN_SHARD_COMMITTEE, - DOMAIN_LIGHT_CLIENT, DOMAIN_CUSTODY_BIT_SLASHING, } -const - forkVersionConversionFn = "'u32.toBytesBE" - # The fork version appears as a number in the preset, - # but our codebase works with a byte array. - - customTypes = { - BASE_REWARD_FACTOR: "'u64", - BLS_WITHDRAWAL_PREFIX: ".byte", - EFFECTIVE_BALANCE_INCREMENT: "'u64", - EJECTION_BALANCE: "'u64", - EPOCHS_PER_SLASHINGS_VECTOR: "'u64", - GENESIS_FORK_VERSION: forkVersionConversionFn, - GENESIS_SLOT: ".Slot", - INACTIVITY_PENALTY_QUOTIENT: "'u64", - MAX_EFFECTIVE_BALANCE: "'u64", - MIN_DEPOSIT_AMOUNT: "'u64", - MIN_EPOCHS_TO_INACTIVITY_PENALTY: "'u64", - MIN_VALIDATOR_WITHDRAWABILITY_DELAY: "'u64", - PHASE_1_FORK_VERSION: forkVersionConversionFn, - PROPOSER_REWARD_QUOTIENT: "'u64", - SECONDS_PER_SLOT: "'u64", - WHISTLEBLOWER_REWARD_QUOTIENT: "'u64", + presetValueTypes* = { + BASE_REWARD_FACTOR: "uint64", + BLS_WITHDRAWAL_PREFIX: "byte", + EFFECTIVE_BALANCE_INCREMENT: "uint64", + EJECTION_BALANCE: "uint64", + EPOCHS_PER_SLASHINGS_VECTOR: "uint64", + GENESIS_FORK_VERSION: "Version", + GENESIS_SLOT: "Slot", + INACTIVITY_PENALTY_QUOTIENT: "uint64", + MAX_EFFECTIVE_BALANCE: "uint64", + MIN_DEPOSIT_AMOUNT: "uint64", + MIN_EPOCHS_TO_INACTIVITY_PENALTY: "uint64", + MIN_VALIDATOR_WITHDRAWABILITY_DELAY: "uint64", + PROPOSER_REWARD_QUOTIENT: "uint64", + SECONDS_PER_SLOT: "uint64", + WHISTLEBLOWER_REWARD_QUOTIENT: "uint64", }.toTable +func parse*(T: type uint64, input: string): T + {.raises: [ValueError, Defect].} = + if input.len > 2 and input[0] == '0' and input[1] == 'x': + parseHex(input, result) + else: + parseInt(input, result) + +template parse*(T: type byte, input: string): T = + byte parse(uint64, input) + +proc parse*(T: type Version, input: string): T = + toBytesBE(uint32 parse(uint64, input)) + +template parse*(T: type Slot, input: string): T = + Slot parse(uint64, input) + +template getType*(presetValue: PresetValue): string = + presetValueTypes.getOrDefault(presetValue, "int") + template entireSet(T: type enum): untyped = {low(T) .. high(T)} -macro loadCustomPreset*(path: static string): untyped = - result = newStmtList() +macro genRuntimePresetType: untyped = + var fields = newTree(nnkRecList) + for field in runtimeValues: + fields.add newTree(nnkIdentDefs, + ident $field, + ident getType(field), + newEmptyNode()) # default value + + result = newTree(nnkObjectTy, + newEmptyNode(), # pragmas + newEmptyNode(), # base type + fields) + +type + RuntimePresetObj* = genRuntimePresetType() + RuntimePreset* = ref RuntimePresetObj + + PresetFile = object + values*: Table[PresetValue, TaintedString] + missingValues*: set[PresetValue] + + PresetFileError = object of CatchableError + +proc readPresetFile(path: string): PresetFile + {.raises: [IOError, PresetFileError, Defect].} = var - presetContents = staticRead(path) - presetConstants = dubiousConstants lineNum = 0 + presetValues = ignoredValues - for line in splitLines(presetContents): + template lineinfo: string = + "$1($2) " % [path, $lineNum] + + template fail(msg) = + raise newException(PresetFileError, lineinfo & msg) + + for line in splitLines(readFile(path)): inc lineNum if line.len == 0 or line[0] == '#': continue - template lineinfo: string = - "$1($2) " % [path, $lineNum] + var lineParts = line.split(":") + if lineParts.len != 2: + fail "Invalid syntax: A preset file should include only assignments in the form 'ConstName: Value'" - var constParts = line.split(":") - if constParts.len != 2: - error lineinfo & "Invalid syntax: A preset file should include only assignments in the form 'ConstName: Value'" + let value = try: parseEnum[PresetValue](lineParts[0]) + except ValueError: fail "Unrecognized constant in a preset: " & lineParts[0] - try: - let constant = parseEnum[BeaconChainConstants](constParts[0]) - if constant in dubiousConstants: continue - if customTypes.hasKey(constant): - constParts.add customTypes[constant] - presetConstants.incl constant - except ValueError: - warning lineinfo & "Unrecognized constant in a preset: " & constParts[0] - continue + if value in ignoredValues: continue + presetValues.incl value + result.add value, lineParts[1] - if constParts.len == 3: - result.add parseStmt("const $1* {.intdefine.} = $2$3" % constParts) - else: - result.add parseStmt("const $1* {.intdefine.} = $2" % constParts) + result.missingValues = PresetValue.entireSet - presetValues - let missingConstants = BeaconChainConstants.entireSet - presetConstants - if missingConstants.card > 0: - warning "Missing constants in preset: " & $missingConstants +macro createConstantsFromPreset*(path: static string): untyped = + result = newStmtList() + + let preset = try: loadPreset(path) + except PresetError as err: error err.msg + + for name, value in preset: + var value = value + if presetValueTypes.hasKey(name): + let typ = presetValueTypes[name] + value = typ & "(" & value & ")" + + result.add parseStmt("const $1* {.intdefine.} = $2" % [name, value]) + + if preset.missingValues.card > 0: + warning "Missing constants in preset: " & $preset.missingValues diff --git a/beacon_chain/spec/presets/v0_12_1/mainnet.nim b/beacon_chain/spec/presets/v0_12_1/mainnet.nim index 9e29e93fe..9f5b47fc1 100644 --- a/beacon_chain/spec/presets/v0_12_1/mainnet.nim +++ b/beacon_chain/spec/presets/v0_12_1/mainnet.nim @@ -14,6 +14,7 @@ import type Slot* = distinct uint64 Epoch* = distinct uint64 + Version* = distinct array[4, byte] {.experimental: "codeReordering".} # SLOTS_PER_EPOCH is use before being defined in spec @@ -41,8 +42,6 @@ const MIN_PER_EPOCH_CHURN_LIMIT* = 4 CHURN_LIMIT_QUOTIENT* = 2^16 SHUFFLE_ROUND_COUNT* = 90 - MIN_GENESIS_ACTIVE_VALIDATOR_COUNT* {.intdefine.} = 16384 - MIN_GENESIS_TIME* {.intdefine.} = 1578009600 HYSTERESIS_QUOTIENT* = 4 HYSTERESIS_DOWNWARD_MULTIPLIER* = 1 @@ -68,13 +67,11 @@ const # Initial values # --------------------------------------------------------------- # https://github.com/ethereum/eth2.0-specs/blob/v0.11.3/configs/mainnet.yaml#L70 - GENESIS_FORK_VERSION* = [0'u8, 0'u8, 0'u8, 0'u8] BLS_WITHDRAWAL_PREFIX* = 0'u8 # Time parameters # --------------------------------------------------------------- # https://github.com/ethereum/eth2.0-specs/blob/v0.11.3/configs/mainnet.yaml#L77 - GENESIS_DELAY* {.intdefine.} = 172800 # 172800 seconds (2 days) SECONDS_PER_SLOT* {.intdefine.} = 12'u64 # Compile with -d:SECONDS_PER_SLOT=1 for 12x faster slots ## TODO consistent time unit across projects, similar to C++ chrono? @@ -193,9 +190,7 @@ const # Time parameters # https://github.com/ethereum/eth2.0-specs/blob/v0.11.3/configs/mainnet.yaml#L199 RANDAO_PENALTY_EPOCHS* = 2 # epochs (12.8 minutes) - EARLY_DERIVED_SECRET_PENALTY_MAX_FUTURE_EPOCHS* = 16384 # epochs (~73 days) EPOCHS_PER_CUSTODY_PERIOD* = 2048 # epochs (~9 days) - CUSTODY_PERIOD_TO_RANDAO_PADDING* = 2048 # epochs (~9 days) MAX_REVEAL_LATENESS_DECREMENT* = 128 # epochs (~14 hours) # Max operations diff --git a/beacon_chain/spec/presets/v0_12_1/minimal.nim b/beacon_chain/spec/presets/v0_12_1/minimal.nim index 91e4926d4..f6b525482 100644 --- a/beacon_chain/spec/presets/v0_12_1/minimal.nim +++ b/beacon_chain/spec/presets/v0_12_1/minimal.nim @@ -14,6 +14,7 @@ import type Slot* = distinct uint64 Epoch* = distinct uint64 + Version* = distinct array[4, byte] {.experimental: "codeReordering".} # SLOTS_PER_EPOCH is use before being defined in spec @@ -33,8 +34,6 @@ const # Changed SHUFFLE_ROUND_COUNT* = 10 - MIN_GENESIS_ACTIVE_VALIDATOR_COUNT* {.intdefine.} = 64 - MIN_GENESIS_TIME* {.intdefine.} = 1578009600 # 3 Jan, 2020 # Unchanged HYSTERESIS_QUOTIENT* = 4 @@ -55,7 +54,6 @@ const # --------------------------------------------------------------- # https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/configs/minimal.yaml#L70 - GENESIS_FORK_VERSION* = [0'u8, 0'u8, 0'u8, 1'u8] BLS_WITHDRAWAL_PREFIX* = 0'u8 # Time parameters @@ -63,7 +61,6 @@ const # https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/configs/minimal.yaml#L77 # Changed: Faster to spin up testnets, but does not give validator # reasonable warning time for genesis - GENESIS_DELAY* {.intdefine.} = 300 # Unchanged SECONDS_PER_SLOT*{.intdefine.} = 6'u64 @@ -172,9 +169,7 @@ const # Time parameters # https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/configs/minimal.yaml#L202 RANDAO_PENALTY_EPOCHS* = 2 - EARLY_DERIVED_SECRET_PENALTY_MAX_FUTURE_EPOCHS* = 4096 # epochs EPOCHS_PER_CUSTODY_PERIOD* = 2048 - CUSTODY_PERIOD_TO_RANDAO_PADDING* = 2048 MAX_REVEAL_LATENESS_DECREMENT* = 128 # Max operations diff --git a/beacon_chain/validator_api.nim b/beacon_chain/validator_api.nim index 44aca3cfb..702e5d029 100644 --- a/beacon_chain/validator_api.nim +++ b/beacon_chain/validator_api.nim @@ -45,7 +45,7 @@ proc installValidatorApiHandlers*(rpcServer: RpcServer, node: BeaconNode) = return (genesis_time: node.blockPool.headState.data.data.genesis_time, genesis_validators_root: node.blockPool.headState.data.data.genesis_validators_root, - genesis_fork_version: Version(GENESIS_FORK_VERSION)) + genesis_fork_version: GENESIS_FORK_VERSION) rpcServer.rpc("get_v1_beacon_states_root") do (stateId: string) -> Eth2Digest: debug "get_v1_beacon_states_root", stateId = stateId @@ -75,8 +75,8 @@ proc installValidatorApiHandlers*(rpcServer: RpcServer, node: BeaconNode) = of "head": node.blockPool.headState.data.data.fork of "genesis": - Fork(previous_version: Version(GENESIS_FORK_VERSION), - current_version: Version(GENESIS_FORK_VERSION), + Fork(previous_version: GENESIS_FORK_VERSION, + current_version: GENESIS_FORK_VERSION, epoch: GENESIS_EPOCH) of "finalized": node.blockPool.withState(node.blockPool.tmpState, node.blockPool.finalizedHead):