nimbus-eth2/beacon_chain/el/eth1_chain.nim

394 lines
15 KiB
Nim

# beacon_chain
# Copyright (c) 2018-2024 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.
{.push raises: [].}
import
std/[deques, tables, strformat],
chronicles, metrics,
../beacon_chain_db,
../spec/[deposit_snapshots, digest, eth2_merkleization, forks, network],
../spec/datatypes/base,
web3/[primitives, eth_api_types],
./merkle_minimal
export beacon_chain_db, deques, digest, base, forks
logScope:
topics = "elchain"
declarePublicGauge eth1_finalized_head,
"Block number of the highest Eth1 block finalized by Eth2 consensus"
declarePublicGauge eth1_finalized_deposits,
"Number of deposits that were finalized by the Eth2 consensus"
declareGauge eth1_chain_len,
"The length of the in-memory chain of Eth1 blocks"
type
Eth1BlockNumber* = uint64
Eth1BlockTimestamp* = uint64
Eth1BlockObj* = object
hash*: Eth2Digest
number*: Eth1BlockNumber
timestamp*: Eth1BlockTimestamp
## Basic properties of the block
## These must be initialized in the constructor
deposits*: seq[DepositData]
## Deposits inside this particular block
depositRoot*: Eth2Digest
depositCount*: uint64
## Global deposits count and hash tree root of the entire sequence
## These are computed when the block is added to the chain (see `addBlock`)
Eth1Block* = ref Eth1BlockObj
Eth1Chain* = object
db: BeaconChainDB
cfg*: RuntimeConfig
finalizedBlockHash*: Eth2Digest
finalizedDepositsMerkleizer*: DepositsMerkleizer
## The latest block that reached a 50% majority vote from
## the Eth2 validators according to the follow distance and
## the ETH1_VOTING_PERIOD
blocks*: Deque[Eth1Block]
## A non-forkable chain of blocks ending at the block with
## ETH1_FOLLOW_DISTANCE offset from the head.
blocksByHash: Table[BlockHash, Eth1Block]
headMerkleizer: DepositsMerkleizer
## Merkleizer state after applying all `blocks`
hasConsensusViolation*: bool
## The local chain contradicts the observed consensus on the network
BlockProposalEth1Data* = object
vote*: Eth1Data
deposits*: seq[Deposit]
hasMissingDeposits*: bool
func asEth2Digest*(x: BlockHash): Eth2Digest =
Eth2Digest(data: array[32, byte](x))
template asBlockHash*(x: Eth2Digest): BlockHash =
BlockHash(x.data)
# https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.7/specs/phase0/validator.md#get_eth1_data
func compute_time_at_slot(genesis_time: uint64, slot: Slot): uint64 =
genesis_time + slot * SECONDS_PER_SLOT
# https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.7/specs/phase0/validator.md#get_eth1_data
func voting_period_start_time(state: ForkedHashedBeaconState): uint64 =
let eth1_voting_period_start_slot =
getStateField(state, slot) - getStateField(state, slot) mod
SLOTS_PER_ETH1_VOTING_PERIOD.uint64
compute_time_at_slot(
getStateField(state, genesis_time), eth1_voting_period_start_slot)
# https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.7/specs/phase0/validator.md#get_eth1_data
func is_candidate_block(cfg: RuntimeConfig,
blk: Eth1Block,
period_start: uint64): bool =
(blk.timestamp + cfg.SECONDS_PER_ETH1_BLOCK * cfg.ETH1_FOLLOW_DISTANCE <= period_start) and
(blk.timestamp + cfg.SECONDS_PER_ETH1_BLOCK * cfg.ETH1_FOLLOW_DISTANCE * 2 >= period_start)
func shortLog*(b: Eth1Block): string =
try:
&"{b.number}:{shortLog b.hash}(deposits = {b.depositCount})"
except ValueError as exc: raiseAssert exc.msg
template findBlock(chain: Eth1Chain, eth1Data: Eth1Data): Eth1Block =
getOrDefault(chain.blocksByHash, asBlockHash(eth1Data.block_hash), nil)
func makeSuccessorWithoutDeposits*(existingBlock: Eth1Block,
successor: BlockObject): Eth1Block =
result = Eth1Block(
hash: successor.hash.asEth2Digest,
number: Eth1BlockNumber successor.number,
timestamp: Eth1BlockTimestamp successor.timestamp)
func latestCandidateBlock(chain: Eth1Chain, periodStart: uint64): Eth1Block =
for i in countdown(chain.blocks.len - 1, 0):
let blk = chain.blocks[i]
if is_candidate_block(chain.cfg, blk, periodStart):
return blk
proc popFirst(chain: var Eth1Chain) =
let removed = chain.blocks.popFirst
chain.blocksByHash.del removed.hash.asBlockHash
eth1_chain_len.set chain.blocks.len.int64
proc addBlock*(chain: var Eth1Chain, newBlock: Eth1Block) =
for deposit in newBlock.deposits:
chain.headMerkleizer.addChunk hash_tree_root(deposit).data
newBlock.depositCount = chain.headMerkleizer.getChunkCount
newBlock.depositRoot = chain.headMerkleizer.getDepositsRoot
chain.blocks.addLast newBlock
chain.blocksByHash[newBlock.hash.asBlockHash] = newBlock
eth1_chain_len.set chain.blocks.len.int64
func toVoteData(blk: Eth1Block): Eth1Data =
Eth1Data(
deposit_root: blk.depositRoot,
deposit_count: blk.depositCount,
block_hash: blk.hash)
func hash*(x: Eth1Data): Hash =
hash(x.block_hash)
proc pruneOldBlocks(chain: var Eth1Chain, depositIndex: uint64) =
## Called on block finalization to delete old and now redundant data.
let initialChunks = chain.finalizedDepositsMerkleizer.getChunkCount
var lastBlock: Eth1Block
while chain.blocks.len > 0:
let blk = chain.blocks.peekFirst
if blk.depositCount >= depositIndex:
break
else:
for deposit in blk.deposits:
chain.finalizedDepositsMerkleizer.addChunk hash_tree_root(deposit).data
chain.popFirst()
lastBlock = blk
if chain.finalizedDepositsMerkleizer.getChunkCount > initialChunks:
chain.finalizedBlockHash = lastBlock.hash
chain.db.putDepositContractSnapshot DepositContractSnapshot(
eth1Block: lastBlock.hash,
depositContractState: chain.finalizedDepositsMerkleizer.toDepositContractState,
blockHeight: lastBlock.number)
eth1_finalized_head.set lastBlock.number.toGaugeValue
eth1_finalized_deposits.set lastBlock.depositCount.toGaugeValue
debug "Eth1 blocks pruned",
newTailBlock = lastBlock.hash,
depositsCount = lastBlock.depositCount
func advanceMerkleizer(chain: Eth1Chain,
merkleizer: var DepositsMerkleizer,
depositIndex: uint64): bool =
if chain.blocks.len == 0:
return depositIndex == merkleizer.getChunkCount
if chain.blocks.peekLast.depositCount < depositIndex:
return false
let
firstBlock = chain.blocks[0]
depositsInLastPrunedBlock = firstBlock.depositCount -
firstBlock.deposits.lenu64
# advanceMerkleizer should always be called shortly after prunning the chain
doAssert depositsInLastPrunedBlock == merkleizer.getChunkCount
for blk in chain.blocks:
for deposit in blk.deposits:
if merkleizer.getChunkCount < depositIndex:
merkleizer.addChunk hash_tree_root(deposit).data
else:
return true
return merkleizer.getChunkCount == depositIndex
iterator getDepositsRange*(chain: Eth1Chain, first, last: uint64): DepositData =
# TODO It's possible to make this faster by performing binary search that
# will locate the blocks holding the `first` and `last` indices.
# TODO There is an assumption here that the requested range will be present
# in the Eth1Chain. This should hold true at the call sites right now,
# but we need to guard the pre-conditions better.
for blk in chain.blocks:
if blk.depositCount <= first:
continue
let firstDepositIdxInBlk = blk.depositCount - blk.deposits.lenu64
if firstDepositIdxInBlk >= last:
break
for i in 0 ..< blk.deposits.lenu64:
let globalIdx = firstDepositIdxInBlk + i
if globalIdx >= first and globalIdx < last:
yield blk.deposits[i]
func lowerBound(chain: Eth1Chain, depositCount: uint64): Eth1Block =
# TODO: This can be replaced with a proper binary search in the
# future, but the `algorithm` module currently requires an
# `openArray`, which the `deques` module can't provide yet.
for eth1Block in chain.blocks:
if eth1Block.depositCount > depositCount:
return
result = eth1Block
proc trackFinalizedState*(chain: var Eth1Chain,
finalizedEth1Data: Eth1Data,
finalizedStateDepositIndex: uint64,
blockProposalExpected = false): bool =
## This function will return true if the ELManager is synced
## to the finalization point.
if chain.blocks.len == 0:
debug "Eth1 chain not initialized"
return false
let latest = chain.blocks.peekLast
if latest.depositCount < finalizedEth1Data.deposit_count:
if blockProposalExpected:
error "The Eth1 chain is not synced",
ourDepositsCount = latest.depositCount,
targetDepositsCount = finalizedEth1Data.deposit_count
return false
let matchingBlock = chain.lowerBound(finalizedEth1Data.deposit_count)
result = if matchingBlock != nil:
if matchingBlock.depositRoot == finalizedEth1Data.deposit_root:
true
else:
error "Corrupted deposits history detected",
ourDepositsCount = matchingBlock.depositCount,
targetDepositsCount = finalizedEth1Data.deposit_count,
ourDepositsRoot = matchingBlock.depositRoot,
targetDepositsRoot = finalizedEth1Data.deposit_root
chain.hasConsensusViolation = true
false
else:
error "The Eth1 chain is in inconsistent state",
checkpointHash = finalizedEth1Data.block_hash,
checkpointDeposits = finalizedEth1Data.deposit_count,
localChainStart = shortLog(chain.blocks.peekFirst),
localChainEnd = shortLog(chain.blocks.peekLast)
chain.hasConsensusViolation = true
false
if result:
chain.pruneOldBlocks(finalizedStateDepositIndex)
# https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.7/specs/phase0/validator.md#get_eth1_data
proc getBlockProposalData*(chain: var Eth1Chain,
state: ForkedHashedBeaconState,
finalizedEth1Data: Eth1Data,
finalizedStateDepositIndex: uint64): BlockProposalEth1Data =
let
periodStart = voting_period_start_time(state)
hasLatestDeposits = chain.trackFinalizedState(finalizedEth1Data,
finalizedStateDepositIndex,
blockProposalExpected = true)
var otherVotesCountTable = initCountTable[Eth1Data]()
for vote in getStateField(state, eth1_data_votes):
let eth1Block = chain.findBlock(vote)
if eth1Block != nil and
eth1Block.depositRoot == vote.deposit_root and
vote.deposit_count >= getStateField(state, eth1_data).deposit_count and
is_candidate_block(chain.cfg, eth1Block, periodStart):
otherVotesCountTable.inc vote
else:
debug "Ignoring eth1 vote",
root = vote.block_hash,
deposits = vote.deposit_count,
depositsRoot = vote.deposit_root,
localDeposits = getStateField(state, eth1_data).deposit_count
let
stateDepositIdx = getStateField(state, eth1_deposit_index)
stateDepositsCount = getStateField(state, eth1_data).deposit_count
# A valid state should never have this condition, but it doesn't hurt
# to be extra defensive here because we are working with uint types
var pendingDepositsCount = if stateDepositsCount > stateDepositIdx:
stateDepositsCount - stateDepositIdx
else:
0
if otherVotesCountTable.len > 0:
let (winningVote, votes) = otherVotesCountTable.largest
debug "Voting on eth1 head with majority", votes
result.vote = winningVote
if uint64((votes + 1) * 2) > SLOTS_PER_ETH1_VOTING_PERIOD:
pendingDepositsCount = winningVote.deposit_count - stateDepositIdx
else:
let latestBlock = chain.latestCandidateBlock(periodStart)
if latestBlock == nil:
debug "No acceptable eth1 votes and no recent candidates. Voting no change"
result.vote = getStateField(state, eth1_data)
else:
debug "No acceptable eth1 votes. Voting for latest candidate"
result.vote = latestBlock.toVoteData
if pendingDepositsCount > 0:
if hasLatestDeposits:
let
totalDepositsInNewBlock = min(MAX_DEPOSITS, pendingDepositsCount)
postStateDepositIdx = stateDepositIdx + pendingDepositsCount
var
deposits = newSeqOfCap[DepositData](totalDepositsInNewBlock)
depositRoots = newSeqOfCap[Eth2Digest](pendingDepositsCount)
for data in chain.getDepositsRange(stateDepositIdx, postStateDepositIdx):
if deposits.lenu64 < totalDepositsInNewBlock:
deposits.add data
depositRoots.add hash_tree_root(data)
var scratchMerkleizer = chain.finalizedDepositsMerkleizer
if chain.advanceMerkleizer(scratchMerkleizer, stateDepositIdx):
let proofs = scratchMerkleizer.addChunksAndGenMerkleProofs(depositRoots)
for i in 0 ..< totalDepositsInNewBlock:
var proof: array[33, Eth2Digest]
proof[0..31] = proofs.getProof(i.int)
proof[32] = default(Eth2Digest)
proof[32].data[0..7] = toBytesLE uint64(postStateDepositIdx)
result.deposits.add Deposit(data: deposits[i], proof: proof)
else:
error "The Eth1 chain is in inconsistent state" # This should not really happen
result.hasMissingDeposits = true
else:
result.hasMissingDeposits = true
func clear*(chain: var Eth1Chain) =
chain.blocks.clear()
chain.blocksByHash.clear()
chain.headMerkleizer = chain.finalizedDepositsMerkleizer
chain.hasConsensusViolation = false
proc init*(T: type Eth1Chain,
cfg: RuntimeConfig,
db: BeaconChainDB,
depositContractBlockNumber: uint64,
depositContractBlockHash: Eth2Digest): T =
let
(finalizedBlockHash, depositContractState) =
if db != nil:
let treeSnapshot = db.getDepositContractSnapshot()
if treeSnapshot.isSome:
(treeSnapshot.get.eth1Block, treeSnapshot.get.depositContractState)
else:
let oldSnapshot = db.getUpgradableDepositSnapshot()
if oldSnapshot.isSome:
(oldSnapshot.get.eth1Block, oldSnapshot.get.depositContractState)
else:
db.putDepositContractSnapshot DepositContractSnapshot(
eth1Block: depositContractBlockHash,
blockHeight: depositContractBlockNumber)
(depositContractBlockHash, default(DepositContractState))
else:
(depositContractBlockHash, default(DepositContractState))
m = DepositsMerkleizer.init(depositContractState)
T(db: db,
cfg: cfg,
finalizedBlockHash: finalizedBlockHash,
finalizedDepositsMerkleizer: m,
headMerkleizer: m)