nimbus-eth2/beacon_chain/consensus_object_pools/blockchain_dag.nim

2880 lines
109 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/[algorithm, sequtils, tables, sets],
stew/[arrayops, assign2, byteutils],
chronos, metrics, results, snappy, chronicles,
../spec/[beaconstate, eth2_merkleization, eth2_ssz_serialization, helpers,
state_transition, validator],
../spec/forks,
../spec/datatypes/[phase0, altair, bellatrix, capella],
".."/[beacon_chain_db, beacon_clock, era_db],
"."/[block_pools_types, block_quarantine]
from ../spec/datatypes/deneb import shortLog
export
eth2_merkleization, eth2_ssz_serialization,
block_pools_types, results, beacon_chain_db
logScope: topics = "chaindag"
# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#interop-metrics
declareGauge beacon_head_root, "Root of the head block of the beacon chain"
declareGauge beacon_head_slot, "Slot of the head block of the beacon chain"
# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#interop-metrics
declareGauge beacon_finalized_epoch, "Current finalized epoch" # On epoch transition
declareGauge beacon_finalized_root, "Current finalized root" # On epoch transition
declareGauge beacon_current_justified_epoch, "Current justified epoch" # On epoch transition
declareGauge beacon_current_justified_root, "Current justified root" # On epoch transition
declareGauge beacon_previous_justified_epoch, "Current previously justified epoch" # On epoch transition
declareGauge beacon_previous_justified_root, "Current previously justified root" # On epoch transition
declareGauge beacon_reorgs_total_total, "Total occurrences of reorganizations of the chain" # On fork choice; backwards-compat name (used to be a counter)
declareGauge beacon_reorgs_total, "Total occurrences of reorganizations of the chain" # Interop copy
declareCounter beacon_state_data_cache_hits, "EpochRef hits"
declareCounter beacon_state_data_cache_misses, "EpochRef misses"
declareCounter beacon_state_rewinds, "State database rewinds"
declareGauge beacon_active_validators, "Number of validators in the active validator set"
declareGauge beacon_current_active_validators, "Number of validators in the active validator set" # Interop copy
declareGauge beacon_pending_deposits, "Number of pending deposits (state.eth1_data.deposit_count - state.eth1_deposit_index)" # On block
declareGauge beacon_processed_deposits_total, "Number of total deposits included on chain" # On block
declareCounter beacon_dag_state_replay_seconds, "Time spent replaying states"
const
EPOCHS_PER_STATE_SNAPSHOT* = 32
## When finality happens, we prune historical states from the database except
## for a snapshot every 32 epochs from which replays can happen - there's a
## balance here between making long replays and saving on disk space
MAX_SLOTS_PER_PRUNE* = SLOTS_PER_EPOCH
## We prune the database incrementally so as not to introduce long
## processing breaks - this number is the maximum number of blocks we allow
## to be pruned every time the prune call is made (once per slot typically)
## unless head is moving faster (ie during sync)
proc putBlock*(
dag: ChainDAGRef, signedBlock: ForkyTrustedSignedBeaconBlock) =
dag.db.putBlock(signedBlock)
proc updateState*(
dag: ChainDAGRef, state: var ForkedHashedBeaconState, bsi: BlockSlotId,
save: bool, cache: var StateCache): bool {.gcsafe.}
template withUpdatedState*(
dag: ChainDAGRef, stateParam: var ForkedHashedBeaconState,
bsiParam: BlockSlotId, okBody: untyped, failureBody: untyped): untyped =
## Helper template that updates stateData to a particular BlockSlot - usage of
## stateData is unsafe outside of block, or across `await` boundaries
block:
let bsi {.inject.} = bsiParam
var cache {.inject.} = StateCache()
if updateState(dag, stateParam, bsi, false, cache):
template bid(): BlockId {.inject, used.} = bsi.bid
template updatedState(): ForkedHashedBeaconState {.inject, used.} = stateParam
okBody
else:
failureBody
func get_effective_balances(
validators: openArray[Validator], epoch: Epoch): seq[Gwei] =
## Get the balances from a state as counted for fork choice
result.newSeq(validators.len) # zero-init
for i in 0 ..< result.len:
# All non-active validators have a 0 balance
let validator = unsafeAddr validators[i]
if validator[].is_active_validator(epoch) and not validator[].slashed:
result[i] = validator[].effective_balance
proc updateValidatorKeys*(dag: ChainDAGRef, validators: openArray[Validator]) =
# Update validator key cache - must be called every time a valid block is
# applied to the state - this is important to ensure that when we sync blocks
# without storing a state (non-epoch blocks essentially), the deposits from
# those blocks are persisted to the in-database cache of immutable validator
# data (but no earlier than that the whole block as been validated)
dag.db.updateImmutableValidators(validators)
proc updateFinalizedBlocks*(db: BeaconChainDB, newFinalized: openArray[BlockId]) =
if db.db.readOnly: return # TODO abstraction leak - where to put this?
db.withManyWrites:
for bid in newFinalized:
db.finalizedBlocks.insert(bid.slot, bid.root)
proc updateFrontfillBlocks*(dag: ChainDAGRef) =
# When backfilling is done and manages to reach the frontfill point, we can
# write the frontfill index knowing that the block information in the
# era files match the chain
if dag.db.db.readOnly: return # TODO abstraction leak - where to put this?
if dag.frontfillBlocks.len == 0 or dag.backfill.slot > GENESIS_SLOT:
return
info "Writing frontfill index", slots = dag.frontfillBlocks.len
dag.db.withManyWrites:
let low = dag.db.finalizedBlocks.low.expect(
"wrote at least tailRef during init")
let blocks = min(low.int, dag.frontfillBlocks.len - 1)
var parent: Eth2Digest
for i in 0..blocks:
let root = dag.frontfillBlocks[i]
if not isZero(root):
dag.db.finalizedBlocks.insert(Slot(i), root)
dag.db.putBeaconBlockSummary(
root, BeaconBlockSummary(slot: Slot(i), parent_root: parent))
parent = root
reset(dag.frontfillBlocks)
func validatorKey*(
dag: ChainDAGRef, index: ValidatorIndex or uint64): Opt[CookedPubKey] =
## Returns the validator pubkey for the index, assuming it's been observed
## at any point in time - this function may return pubkeys for indicies that
## are not (yet) part of the head state (if the key has been observed on a
## non-head branch)!
dag.db.immutableValidators.load(index)
template is_merge_transition_complete*(
stateParam: ForkedHashedBeaconState): bool =
withState(stateParam):
when consensusFork >= ConsensusFork.Bellatrix:
is_merge_transition_complete(forkyState.data)
else:
false
func effective_balances*(epochRef: EpochRef): seq[Gwei] =
try:
SSZ.decode(snappy.decode(epochRef.effective_balances_bytes, uint32.high),
List[Gwei, Limit VALIDATOR_REGISTRY_LIMIT]).toSeq()
except CatchableError as exc:
raiseAssert exc.msg
func getBlockRef*(dag: ChainDAGRef, root: Eth2Digest): Opt[BlockRef] =
## Retrieve a resolved block reference, if available - this function does
## not return historical finalized blocks, see `getBlockIdAtSlot` for a
## function that covers the entire known history
let key = KeyedBlockRef.asLookupKey(root)
# HashSet lacks the api to do check-and-get in one lookup - `[]` will return
# the copy of the instance in the set which has more fields than `root` set!
if key in dag.forkBlocks:
try: ok(dag.forkBlocks[key].blockRef())
except KeyError: raiseAssert "contains"
else:
err()
func getBlockIdAtSlot*(
state: ForkyHashedBeaconState, slot: Slot): Opt[BlockSlotId] =
## Use given state to attempt to find a historical `BlockSlotId`.
if slot > state.data.slot:
return Opt.none(BlockSlotId) # State does not know about requested slot
if state.data.slot > slot + SLOTS_PER_HISTORICAL_ROOT:
return Opt.none(BlockSlotId) # Cache has expired
var idx = slot mod SLOTS_PER_HISTORICAL_ROOT
let root =
if slot == state.data.slot:
state.latest_block_root
else:
state.data.block_roots[idx]
var bid = BlockId(slot: slot, root: root)
let availableSlots =
min(slot.uint64, slot + SLOTS_PER_HISTORICAL_ROOT - state.data.slot)
for i in 0 ..< availableSlots:
if idx == 0:
idx = SLOTS_PER_HISTORICAL_ROOT
dec idx
if state.data.block_roots[idx] != root:
return Opt.some BlockSlotId.init(bid, slot)
dec bid.slot
if bid.slot == GENESIS_SLOT:
return Opt.some BlockSlotId.init(bid, slot)
Opt.none(BlockSlotId) # Unknown if there are more empty slots before
func getBlockIdAtSlot*(dag: ChainDAGRef, slot: Slot): Opt[BlockSlotId] =
## Retrieve the canonical block at the given slot, or the last block that
## comes before - similar to atSlot, but without the linear scan - may hit
## the database to look up early indices.
if slot > dag.finalizedHead.slot:
return dag.head.atSlot(slot).toBlockSlotId() # iterate to the given slot
if dag.finalizedHead.blck == nil:
# Not initialized yet (in init)
return Opt.none(BlockSlotId)
if slot >= dag.finalizedHead.blck.slot:
# finalized head is still in memory
return dag.finalizedHead.blck.atSlot(slot).toBlockSlotId()
# Load from memory, if the block ID is sufficiently recent.
# For checkpoint sync, this is the only available of historical block IDs
# until sufficient blocks have been backfilled.
template tryWithState(state: ForkedHashedBeaconState) =
block:
withState(state):
# State must be a descendent of the finalized chain to be viable
let finBsi = forkyState.getBlockIdAtSlot(dag.finalizedHead.slot)
if finBsi.isSome and # DAG finalized bid slot wrong if CP not @ epoch
finBsi.unsafeGet.bid.root == dag.finalizedHead.blck.bid.root:
let bsi = forkyState.getBlockIdAtSlot(slot)
if bsi.isSome:
return bsi
tryWithState dag.headState
tryWithState dag.epochRefState
tryWithState dag.clearanceState
# Fallback to database, this only works for backfilled blocks
let finlow = dag.db.finalizedBlocks.low.expect("at least tailRef written")
if slot >= finlow:
var pos = slot
while true:
let root = dag.db.finalizedBlocks.get(pos)
if root.isSome():
return ok BlockSlotId.init(
BlockId(root: root.get(), slot: pos), slot)
doAssert pos > finlow, "We should have returned the finlow"
pos = pos - 1
if slot == GENESIS_SLOT and dag.genesis.isSome():
return ok dag.genesis.get().atSlot()
err() # not backfilled yet
proc containsBlock(
cfg: RuntimeConfig, db: BeaconChainDB, slot: Slot, root: Eth2Digest): bool =
db.containsBlock(root, cfg.consensusForkAtEpoch(slot.epoch))
proc containsBlock*(dag: ChainDAGRef, bid: BlockId): bool =
dag.cfg.containsBlock(dag.db, bid.slot, bid.root)
proc getForkedBlock*(db: BeaconChainDB, root: Eth2Digest):
Opt[ForkedTrustedSignedBeaconBlock] =
# When we only have a digest, we don't know which fork it's from so we try
# them one by one - this should be used sparingly
static: doAssert high(ConsensusFork) == ConsensusFork.Electra
if (let blck = db.getBlock(root, electra.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
elif (let blck = db.getBlock(root, deneb.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
elif (let blck = db.getBlock(root, capella.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
elif (let blck = db.getBlock(root, bellatrix.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
elif (let blck = db.getBlock(root, altair.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
elif (let blck = db.getBlock(root, phase0.TrustedSignedBeaconBlock);
blck.isSome()):
ok(ForkedTrustedSignedBeaconBlock.init(blck.get()))
else:
err()
proc getBlock*(
dag: ChainDAGRef, bid: BlockId,
T: type ForkyTrustedSignedBeaconBlock): Opt[T] =
dag.db.getBlock(bid.root, T) or
getBlock(
dag.era, getStateField(dag.headState, historical_roots).asSeq,
dag.headState.historical_summaries().asSeq,
bid.slot, Opt[Eth2Digest].ok(bid.root), T)
proc getBlockSSZ*(dag: ChainDAGRef, bid: BlockId, bytes: var seq[byte]): bool =
# Load the SSZ-encoded data of a block into `bytes`, overwriting the existing
# content
let fork = dag.cfg.consensusForkAtEpoch(bid.slot.epoch)
dag.db.getBlockSSZ(bid.root, bytes, fork) or
(bid.slot <= dag.finalizedHead.slot and
getBlockSSZ(
dag.era, getStateField(dag.headState, historical_roots).asSeq,
dag.headState.historical_summaries().asSeq,
bid.slot, bytes).isOk() and bytes.len > 0)
proc getBlockSZ*(dag: ChainDAGRef, bid: BlockId, bytes: var seq[byte]): bool =
# Load the snappy-frame-compressed ("SZ") SSZ-encoded data of a block into
# `bytes`, overwriting the existing content
# careful: there are two snappy encodings in use, with and without framing!
# Returns true if the block is found, false if not
let fork = dag.cfg.consensusForkAtEpoch(bid.slot.epoch)
dag.db.getBlockSZ(bid.root, bytes, fork) or
(bid.slot <= dag.finalizedHead.slot and
getBlockSZ(
dag.era, getStateField(dag.headState, historical_roots).asSeq,
dag.headState.historical_summaries().asSeq,
bid.slot, bytes).isOk and bytes.len > 0)
proc getForkedBlock*(
dag: ChainDAGRef, bid: BlockId): Opt[ForkedTrustedSignedBeaconBlock] =
let fork = dag.cfg.consensusForkAtEpoch(bid.slot.epoch)
result.ok(ForkedTrustedSignedBeaconBlock(kind: fork))
withBlck(result.get()):
type T = type(forkyBlck)
forkyBlck = getBlock(dag, bid, T).valueOr:
getBlock(
dag.era, getStateField(dag.headState, historical_roots).asSeq,
dag.headState.historical_summaries().asSeq,
bid.slot, Opt[Eth2Digest].ok(bid.root), T).valueOr:
result.err()
return
proc getBlockId*(db: BeaconChainDB, root: Eth2Digest): Opt[BlockId] =
block: # We might have a summary in the database
let summary = db.getBeaconBlockSummary(root)
if summary.isOk():
return ok(BlockId(root: root, slot: summary.get().slot))
block:
# We might have a block without having written a summary - this can happen
# if there was a crash between writing the block and writing the summary,
# specially in databases written by older nimbus versions
let forked = db.getForkedBlock(root)
if forked.isSome():
# Shouldn't happen too often but..
let
blck = forked.get()
summary = withBlck(blck): forkyBlck.message.toBeaconBlockSummary()
debug "Writing summary", blck = shortLog(blck)
db.putBeaconBlockSummary(root, summary)
return ok(BlockId(root: root, slot: summary.slot))
err()
proc getBlockId*(dag: ChainDAGRef, root: Eth2Digest): Opt[BlockId] =
## Look up block id by root in history - useful for turning a root into a
## slot - may hit the database, may return blocks that have since become
## unviable - use `getBlockIdAtSlot` to check that the block is still viable
## if used in a sensitive context
block: # If we have a BlockRef, this is the fastest way to get a block id
let blck = dag.getBlockRef(root)
if blck.isOk():
return ok(blck.get().bid)
dag.db.getBlockId(root)
proc getForkedBlock*(
dag: ChainDAGRef, root: Eth2Digest): Opt[ForkedTrustedSignedBeaconBlock] =
let bid = dag.getBlockId(root)
if bid.isSome():
dag.getForkedBlock(bid.get())
else:
# In case we didn't have a summary - should be rare, but ..
dag.db.getForkedBlock(root)
func isCanonical*(dag: ChainDAGRef, bid: BlockId): bool =
## Returns `true` if the given `bid` is part of the history selected by
## `dag.head`.
let current = dag.getBlockIdAtSlot(bid.slot).valueOr:
return false # We don't know, so ..
return current.bid == bid
func isFinalized*(dag: ChainDAGRef, bid: BlockId): bool =
## Returns `true` if the given `bid` is part of the finalized history
## selected by `dag.finalizedHead`.
dag.isCanonical(bid) and (bid.slot <= dag.finalizedHead.slot)
func parent*(dag: ChainDAGRef, bid: BlockId): Opt[BlockId] =
if bid.slot == 0:
return err()
if bid.slot > dag.finalizedHead.slot:
# Make sure we follow the correct history as there may be forks
let blck = ? dag.getBlockRef(bid.root)
doAssert not isNil(blck.parent), "should reach finalized head"
return ok blck.parent.bid
let bids = ? dag.getBlockIdAtSlot(bid.slot - 1)
ok(bids.bid)
func parentOrSlot*(dag: ChainDAGRef, bsi: BlockSlotId): Opt[BlockSlotId] =
if bsi.slot == 0:
return err()
if bsi.isProposed:
let parent = ? dag.parent(bsi.bid)
ok BlockSlotId.init(parent, bsi.slot)
else:
ok BlockSlotId.init(bsi.bid, bsi.slot - 1)
func atSlot*(dag: ChainDAGRef, bid: BlockId, slot: Slot): Opt[BlockSlotId] =
if bid.slot > dag.finalizedHead.slot:
let blck = ? dag.getBlockRef(bid.root)
if slot > dag.finalizedHead.slot:
return blck.atSlot(slot).toBlockSlotId()
else:
# Check if the given `bid` is still part of history - it might hail from an
# orphaned fork
let existing = ? dag.getBlockIdAtSlot(bid.slot)
if existing.bid != bid:
return err() # Not part of known / relevant history
if existing.slot == slot: # and bid.slot == slot
return ok existing
if bid.slot <= slot:
ok BlockSlotId.init(bid, slot)
else:
dag.getBlockIdAtSlot(slot)
func nextTimestamp[I, T](cache: var LRUCache[I, T]): uint32 =
if cache.timestamp == uint32.high:
for i in 0 ..< I:
template e: untyped = cache.entries[i]
if e.lastUsed != 0:
e.lastUsed = 1
cache.timestamp = 1
inc cache.timestamp
cache.timestamp
template peekIt[I, T](cache: var LRUCache[I, T], predicate: untyped): Opt[T] =
block:
var res: Opt[T]
for i in 0 ..< I:
template e: untyped = cache.entries[i]
template it: untyped {.inject, used.} = e.value
if e.lastUsed != 0 and predicate:
res.ok it
break
res
template findIt[I, T](cache: var LRUCache[I, T], predicate: untyped): Opt[T] =
block:
var res: Opt[T]
for i in 0 ..< I:
template e: untyped = cache.entries[i]
template it: untyped {.inject, used.} = e.value
if e.lastUsed != 0 and predicate:
e.lastUsed = cache.nextTimestamp
res.ok it
break
res
template delIt[I, T](cache: var LRUCache[I, T], predicate: untyped) =
block:
for i in 0 ..< I:
template e: untyped = cache.entries[i]
template it: untyped {.inject, used.} = e.value
if e.lastUsed != 0 and predicate:
e.reset()
func put[I, T](cache: var LRUCache[I, T], value: T) =
var lru = 0
block:
var min = uint32.high
for i in 0 ..< I:
template e: untyped = cache.entries[i]
if e.lastUsed < min:
min = e.lastUsed
lru = i
if min == 0:
break
template e: untyped = cache.entries[lru]
e.value = value
e.lastUsed = cache.nextTimestamp
func epochAncestor(dag: ChainDAGRef, bid: BlockId, epoch: Epoch):
Opt[BlockSlotId] =
## The epoch ancestor is the last block that has an effect on the epoch-
## related state data, as updated in `process_epoch` - this block determines
## effective balances, validator addtions and removals etc and serves as a
## base for `EpochRef` construction.
if epoch < dag.tail.slot.epoch or bid.slot < dag.tail.slot:
# Not enough information in database to meaningfully process pre-tail epochs
return Opt.none BlockSlotId
let
dependentSlot =
if epoch == dag.tail.slot.epoch:
# Use the tail as "dependent block" - this may be the genesis block, or,
# in the case of checkpoint sync, the checkpoint block
dag.tail.slot
else:
epoch.start_slot() - 1
bsi = ? dag.atSlot(bid, dependentSlot)
epochSlot =
if epoch == dag.tail.slot.epoch:
dag.tail.slot
else:
epoch.start_slot()
ok BlockSlotId(bid: bsi.bid, slot: epochSlot)
func epochKey(dag: ChainDAGRef, bid: BlockId, epoch: Epoch): Opt[EpochKey] =
## The state transition works by storing information from blocks in a
## "working" area until the epoch transition, then batching work collected
## during the epoch. Thus, last block in the ancestor epochs is the block
## that has an impact on epoch currently considered.
##
## This function returns an epoch key pointing to that epoch boundary, i.e. the
## boundary where the last block has been applied to the state and epoch
## processing has been done.
let bsi = dag.epochAncestor(bid, epoch).valueOr:
return Opt.none(EpochKey)
Opt.some(EpochKey(bid: bsi.bid, epoch: epoch))
func putShufflingRef*(dag: ChainDAGRef, shufflingRef: ShufflingRef) =
## Store shuffling in the cache
if shufflingRef.epoch < dag.finalizedHead.slot.epoch():
# Only cache epoch information for unfinalized blocks - earlier states
# are seldomly used (ie RPC), so no need to cache
return
dag.shufflingRefs.put shufflingRef
func findShufflingRef*(
dag: ChainDAGRef, bid: BlockId, epoch: Epoch): Opt[ShufflingRef] =
## Lookup a shuffling in the cache, returning `none` if it's not present - see
## `getShufflingRef` for a version that creates a new instance if it's missing
let
dependent_slot = epoch.attester_dependent_slot()
dependent_bsi = ? dag.atSlot(bid, dependent_slot)
# Check `ShufflingRef` cache
let shufflingRef = dag.shufflingRefs.findIt(
it.epoch == epoch and it.attester_dependent_root == dependent_bsi.bid.root)
if shufflingRef.isOk:
return shufflingRef
# Check `EpochRef` cache
let epochRef = dag.epochRefs.peekIt(
it.shufflingRef.epoch == epoch and
it.shufflingRef.attester_dependent_root == dependent_bsi.bid.root)
if epochRef.isOk:
dag.putShufflingRef(epochRef.get.shufflingRef)
return ok epochRef.get.shufflingRef
err()
func findEpochRef*(
dag: ChainDAGRef, bid: BlockId, epoch: Epoch): Opt[EpochRef] =
## Lookup an EpochRef in the cache, returning `none` if it's not present - see
## `getEpochRef` for a version that creates a new instance if it's missing
let key = ? dag.epochKey(bid, epoch)
dag.epochRefs.findIt(it.key == key)
func putEpochRef(dag: ChainDAGRef, epochRef: EpochRef) =
if epochRef.epoch < dag.finalizedHead.slot.epoch():
# Only cache epoch information for unfinalized blocks - earlier states
# are seldomly used (ie RPC), so no need to cache
return
dag.epochRefs.put epochRef
func init*(
T: type ShufflingRef, state: ForkedHashedBeaconState,
cache: var StateCache, epoch: Epoch): T =
let attester_dependent_root =
withState(state): forkyState.dependent_root(epoch.get_previous_epoch)
ShufflingRef(
epoch: epoch,
attester_dependent_root: attester_dependent_root,
shuffled_active_validator_indices:
cache.get_shuffled_active_validator_indices(state, epoch),
)
func init*(
T: type EpochRef, dag: ChainDAGRef, state: ForkedHashedBeaconState,
cache: var StateCache): T =
let
epoch = state.get_current_epoch()
proposer_dependent_root = withState(state):
forkyState.proposer_dependent_root
shufflingRef = dag.findShufflingRef(state.latest_block_id, epoch).valueOr:
let tmp = ShufflingRef.init(state, cache, epoch)
dag.putShufflingRef(tmp)
tmp
total_active_balance = withState(state):
get_total_active_balance(forkyState.data, cache)
epochRef = EpochRef(
key: dag.epochKey(state.latest_block_id, epoch).expect(
"Valid epoch ancestor when processing state"),
eth1_data:
getStateField(state, eth1_data),
eth1_deposit_index:
getStateField(state, eth1_deposit_index),
checkpoints:
FinalityCheckpoints(
justified: getStateField(state, current_justified_checkpoint),
finalized: getStateField(state, finalized_checkpoint)),
# beacon_proposers: Separately filled below
proposer_dependent_root: proposer_dependent_root,
shufflingRef: shufflingRef,
total_active_balance: total_active_balance
)
epochStart = epoch.start_slot()
for i in 0'u64..<SLOTS_PER_EPOCH:
epochRef.beacon_proposers[i] =
get_beacon_proposer_index(state, cache, epochStart + i)
# When fork choice runs, it will need the effective balance of the justified
# checkpoint - we pre-load the balances here to avoid rewinding the justified
# state later and compress them because not all checkpoints end up being used
# for fork choice - specially during long periods of non-finalization
func snappyEncode(inp: openArray[byte]): seq[byte] =
try:
snappy.encode(inp)
except CatchableError as err:
raiseAssert err.msg
epochRef.effective_balances_bytes =
snappyEncode(SSZ.encode(
List[Gwei, Limit VALIDATOR_REGISTRY_LIMIT](
get_effective_balances(getStateField(state, validators).asSeq, epoch))))
epochRef
func loadStateCache(
dag: ChainDAGRef, cache: var StateCache, bid: BlockId, epoch: Epoch) =
# When creating a state cache, we want the current and the previous epoch
# information to be preloaded as both of these are used in state transition
# functions
template load(e: Epoch) =
block:
let epoch = e
if epoch notin cache.shuffled_active_validator_indices:
let shufflingRef = dag.findShufflingRef(bid, epoch)
if shufflingRef.isSome():
cache.shuffled_active_validator_indices[epoch] =
shufflingRef[][].shuffled_active_validator_indices
let epochRef = dag.findEpochRef(bid, epoch)
if epochRef.isSome():
let start_slot = epoch.start_slot()
for i, idx in epochRef[][].beacon_proposers:
cache.beacon_proposer_indices[start_slot + i] = idx
cache.total_active_balance[epoch] = epochRef[][].total_active_balance
load(epoch)
if epoch > 0:
load(epoch - 1)
if dag.head != nil: # nil during init.. sigh
let period = dag.head.slot.sync_committee_period
if period == epoch.sync_committee_period and
period notin cache.sync_committees and
period > dag.cfg.ALTAIR_FORK_EPOCH.sync_committee_period():
# If the block we're aiming for shares ancestry with head, we can reuse
# the cached head committee - this accounts for most "live" cases like
# syncing and checking blocks since the committees rarely change
let periodBsi = dag.atSlot(bid, period.start_slot)
if periodBsi.isSome and periodBsi ==
dag.atSlot(dag.head.bid, period.start_slot):
# We often end up sharing sync committees with head during sync / gossip
# validation / head updates
cache.sync_committees[period] = dag.headSyncCommittees
func containsForkBlock*(dag: ChainDAGRef, root: Eth2Digest): bool =
## Checks for blocks at the finalized checkpoint or newer
KeyedBlockRef.asLookupKey(root) in dag.forkBlocks
func isFinalizedStateSnapshot(slot: Slot): bool =
slot.is_epoch and slot.epoch mod EPOCHS_PER_STATE_SNAPSHOT == 0
func isStateCheckpoint(dag: ChainDAGRef, bsi: BlockSlotId): bool =
## State checkpoints are the points in time for which we store full state
## snapshots, which later serve as rewind starting points when replaying state
## transitions from database, for example during reorgs.
##
# As a policy, we only store epoch boundary states without the epoch block
# (if it exists) applied - the rest can be reconstructed by loading an epoch
# boundary state and applying the missing blocks.
# We also avoid states that were produced with empty slots only - as such,
# there is only a checkpoint for the first epoch after a block.
# The tail block also counts as a state checkpoint!
(bsi.isProposed and bsi.bid == dag.tail) or
(bsi.slot.is_epoch and bsi.slot.epoch == (bsi.bid.slot.epoch + 1))
proc getState(
db: BeaconChainDB, cfg: RuntimeConfig, block_root: Eth2Digest, slot: Slot,
state: var ForkedHashedBeaconState, rollback: RollbackProc): bool =
let state_root = db.getStateRoot(block_root, slot).valueOr:
return false
db.getState(cfg.consensusForkAtEpoch(slot.epoch), state_root, state, rollback)
proc containsState*(
db: BeaconChainDB, cfg: RuntimeConfig, block_root: Eth2Digest,
slots: Slice[Slot], legacy = true): bool =
var slot = slots.b
while slot >= slots.a:
let state_root = db.getStateRoot(block_root, slot)
if state_root.isSome() and
db.containsState(
cfg.consensusForkAtEpoch(slot.epoch), state_root.get(), legacy):
return true
if slot == slots.a: # avoid underflow at genesis
break
slot -= 1
false
proc getState*(
db: BeaconChainDB, cfg: RuntimeConfig, block_root: Eth2Digest,
slots: Slice[Slot], state: var ForkedHashedBeaconState,
rollback: RollbackProc): bool =
var slot = slots.b
while slot >= slots.a:
let state_root = db.getStateRoot(block_root, slot)
if state_root.isSome() and
db.getState(
cfg.consensusForkAtEpoch(slot.epoch), state_root.get(), state,
rollback):
return true
if slot == slots.a: # avoid underflow at genesis
break
slot -= 1
false
proc getState(
dag: ChainDAGRef, bsi: BlockSlotId, state: var ForkedHashedBeaconState): bool =
## Load a state from the database given a block and a slot - this will first
## lookup the state root in the state root table then load the corresponding
## state, if it exists
if not dag.isStateCheckpoint(bsi):
return false
let rollbackAddr =
# Any restore point will do as long as it's not the object being updated
if unsafeAddr(state) == unsafeAddr(dag.headState):
unsafeAddr dag.clearanceState
else:
unsafeAddr dag.headState
let v = addr state
func rollback() =
assign(v[], rollbackAddr[])
dag.db.getState(dag.cfg, bsi.bid.root, bsi.slot, state, rollback)
proc getStateByParent(
dag: ChainDAGRef, bid: BlockId, state: var ForkedHashedBeaconState): bool =
## Try to load the state referenced by the parent of the given `bid` - this
## state can be used to advance to the `bid` state itself.
let slot = bid.slot
let
summary = dag.db.getBeaconBlockSummary(bid.root).valueOr:
return false
parentMinSlot =
dag.db.getBeaconBlockSummary(summary.parent_root).
map(proc(x: auto): auto = x.slot).valueOr:
# in the cases that we don't have slot information, we'll search for the
# state for a few back from the `bid` slot - if there are gaps of empty
# slots larger than this, we will not be able to load the state using this
# trick
if slot.uint64 >= (EPOCHS_PER_STATE_SNAPSHOT * 2) * SLOTS_PER_EPOCH:
slot - (EPOCHS_PER_STATE_SNAPSHOT * 2) * SLOTS_PER_EPOCH
else:
Slot(0)
let rollbackAddr =
# Any restore point will do as long as it's not the object being updated
if unsafeAddr(state) == unsafeAddr(dag.headState):
unsafeAddr dag.clearanceState
else:
unsafeAddr dag.headState
let v = addr state
func rollback() =
assign(v[], rollbackAddr[])
dag.db.getState(
dag.cfg, summary.parent_root, parentMinSlot..slot, state, rollback)
proc getNearbyState(
dag: ChainDAGRef, state: var ForkedHashedBeaconState, bid: BlockId,
lowSlot: Slot): Opt[void] =
## Load state from DB that is close to `bid` and has at least slot `lowSlot`.
var
e = bid.slot.epoch
b = bid
while true:
let stateSlot = e.start_slot
if stateSlot < lowSlot:
return err()
b = (? dag.atSlot(b, max(stateSlot, 1.Slot) - 1)).bid
let bsi = BlockSlotId.init(b, stateSlot)
if not dag.getState(bsi, state):
if e == GENESIS_EPOCH:
return err()
dec e
continue
return ok()
proc currentSyncCommitteeForPeriod*(
dag: ChainDAGRef,
tmpState: var ForkedHashedBeaconState,
period: SyncCommitteePeriod): Opt[SyncCommittee] =
## Fetch a `SyncCommittee` for a given sync committee period.
## For non-finalized periods, follow the chain as selected by fork choice.
let lowSlot = max(dag.tail.slot, dag.cfg.ALTAIR_FORK_EPOCH.start_slot)
if period < lowSlot.sync_committee_period:
return err()
let
periodStartSlot = period.start_slot
syncCommitteeSlot = max(periodStartSlot, lowSlot)
bsi = ? dag.getBlockIdAtSlot(syncCommitteeSlot)
dag.withUpdatedState(tmpState, bsi) do:
withState(updatedState):
when consensusFork >= ConsensusFork.Altair:
ok forkyState.data.current_sync_committee
else: err()
do: err()
proc getBlockIdAtSlot*(
dag: ChainDAGRef, state: ForkyHashedBeaconState, slot: Slot): Opt[BlockId] =
if slot >= state.data.slot:
Opt.some state.latest_block_id
elif state.data.slot <= slot + SLOTS_PER_HISTORICAL_ROOT:
dag.getBlockId(state.data.get_block_root_at_slot(slot))
else:
Opt.none(BlockId)
proc updateBeaconMetrics(
state: ForkedHashedBeaconState, bid: BlockId, cache: var StateCache) =
# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#additional-metrics
# both non-negative, so difference can't overflow or underflow int64
beacon_head_root.set(bid.root.toGaugeValue)
beacon_head_slot.set(bid.slot.toGaugeValue)
withState(state):
beacon_pending_deposits.set(
(forkyState.data.eth1_data.deposit_count -
forkyState.data.eth1_deposit_index).toGaugeValue)
beacon_processed_deposits_total.set(
forkyState.data.eth1_deposit_index.toGaugeValue)
beacon_current_justified_epoch.set(
forkyState.data.current_justified_checkpoint.epoch.toGaugeValue)
beacon_current_justified_root.set(
forkyState.data.current_justified_checkpoint.root.toGaugeValue)
beacon_previous_justified_epoch.set(
forkyState.data.previous_justified_checkpoint.epoch.toGaugeValue)
beacon_previous_justified_root.set(
forkyState.data.previous_justified_checkpoint.root.toGaugeValue)
beacon_finalized_epoch.set(
forkyState.data.finalized_checkpoint.epoch.toGaugeValue)
beacon_finalized_root.set(
forkyState.data.finalized_checkpoint.root.toGaugeValue)
let active_validators = count_active_validators(
forkyState.data, forkyState.data.slot.epoch, cache).toGaugeValue
beacon_active_validators.set(active_validators)
beacon_current_active_validators.set(active_validators)
import blockchain_dag_light_client
export
blockchain_dag_light_client.getLightClientBootstrap,
blockchain_dag_light_client.getLightClientUpdateForPeriod,
blockchain_dag_light_client.getLightClientFinalityUpdate,
blockchain_dag_light_client.getLightClientOptimisticUpdate
proc putState(dag: ChainDAGRef, state: ForkedHashedBeaconState, bid: BlockId) =
# Store a state and its root
let slot = getStateField(state, slot)
logScope:
blck = shortLog(bid)
stateSlot = shortLog(slot)
stateRoot = shortLog(getStateRoot(state))
if not dag.isStateCheckpoint(BlockSlotId.init(bid, slot)):
return
# Don't consider legacy tables here, they are slow to read so we'll want to
# rewrite things in the new table anyway.
if dag.db.containsState(
dag.cfg.consensusForkAtEpoch(slot.epoch), getStateRoot(state),
legacy = false):
return
let startTick = Moment.now()
# Ideally we would save the state and the root lookup cache in a single
# transaction to prevent database inconsistencies, but the state loading code
# is resilient against one or the other going missing
withState(state):
dag.db.putState(forkyState)
debug "Stored state", putStateDur = Moment.now() - startTick
proc advanceSlots*(
dag: ChainDAGRef, state: var ForkedHashedBeaconState, slot: Slot, save: bool,
cache: var StateCache, info: var ForkedEpochInfo) =
# Given a state, advance it zero or more slots by applying empty slot
# processing - the state must be positioned at or before `slot`
doAssert getStateField(state, slot) <= slot
let stateBid = state.latest_block_id
while getStateField(state, slot) < slot:
let
preEpoch = getStateField(state, slot).epoch
loadStateCache(dag, cache, stateBid, getStateField(state, slot).epoch)
process_slots(
dag.cfg, state, getStateField(state, slot) + 1, cache, info,
dag.updateFlags).expect("process_slots shouldn't fail when state slot is correct")
if save:
dag.putState(state, stateBid)
# The reward information in the state transition is computed for epoch
# transitions - when transitioning into epoch N, the activities in epoch
# N-2 are translated into balance updates, and this is what we capture
# in the monitor. This may be inaccurate during a deep reorg (>1 epoch)
# which is an acceptable tradeoff for monitoring.
withState(state):
let postEpoch = forkyState.data.slot.epoch
if preEpoch != postEpoch and postEpoch >= 2:
var proposers: array[SLOTS_PER_EPOCH, Opt[ValidatorIndex]]
let epochRef = dag.findEpochRef(stateBid, postEpoch - 2)
if epochRef.isSome():
proposers = epochRef[][].beacon_proposers
dag.validatorMonitor[].registerEpochInfo(
forkyState.data, proposers, info)
proc applyBlock(
dag: ChainDAGRef, state: var ForkedHashedBeaconState, bid: BlockId,
cache: var StateCache, info: var ForkedEpochInfo): Result[void, cstring] =
loadStateCache(dag, cache, bid, getStateField(state, slot).epoch)
discard case dag.cfg.consensusForkAtEpoch(bid.slot.epoch)
of ConsensusFork.Phase0:
let data = getBlock(dag, bid, phase0.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
of ConsensusFork.Altair:
let data = getBlock(dag, bid, altair.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
of ConsensusFork.Bellatrix:
let data = getBlock(dag, bid, bellatrix.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
of ConsensusFork.Capella:
let data = getBlock(dag, bid, capella.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
of ConsensusFork.Deneb:
let data = getBlock(dag, bid, deneb.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
of ConsensusFork.Electra:
let data = getBlock(dag, bid, electra.TrustedSignedBeaconBlock).valueOr:
return err("Block load failed")
? state_transition(
dag.cfg, state, data, cache, info,
dag.updateFlags + {slotProcessed}, noRollback)
ok()
proc init*(T: type ChainDAGRef, cfg: RuntimeConfig, db: BeaconChainDB,
validatorMonitor: ref ValidatorMonitor, updateFlags: UpdateFlags,
eraPath = ".",
onBlockCb: OnBlockCallback = nil, onHeadCb: OnHeadCallback = nil,
onReorgCb: OnReorgCallback = nil, onFinCb: OnFinalizedCallback = nil,
vanityLogs = default(VanityLogs),
lcDataConfig = default(LightClientDataConfig)): ChainDAGRef =
cfg.checkForkConsistency()
doAssert updateFlags - {strictVerification} == {},
"Other flags not supported in ChainDAG"
# TODO we require that the db contains both a head and a tail block -
# asserting here doesn't seem like the right way to go about it however..
# Tail is the first block for which we can construct a state - either
# genesis or a checkpoint
let
startTick = Moment.now()
genesisRoot = db.getGenesisBlock()
tailRoot = db.getTailBlock().expect(
"preInit should have initialized the database with a tail block root")
tail = db.getBlockId(tailRoot).expect(
"tail block summary in database, database corrupt?")
headRoot = db.getHeadBlock().expect("head root, database corrupt?")
head = db.getBlockId(headRoot).expect("head block id, database corrupt?")
# Have to be careful with this instance, it is not yet fully initialized so
# as to avoid having to allocate a separate "init" state
dag = ChainDAGRef(
db: db,
validatorMonitor: validatorMonitor,
genesis: genesisRoot.map(
proc(x: auto): auto = BlockId(root: x, slot: GENESIS_SLOT)),
tail: tail,
# The only allowed flag right now is strictVerification, as the others all
# allow skipping some validation.
updateFlags: updateFlags * {strictVerification},
cfg: cfg,
vanityLogs: vanityLogs,
lcDataStore: initLightClientDataStore(
lcDataConfig, cfg, db.getLightClientDataDB()),
onBlockAdded: onBlockCb,
onHeadChanged: onHeadCb,
onReorgHappened: onReorgCb,
onFinHappened: onFinCb,
)
loadTick = Moment.now()
var
headRef, curRef: BlockRef
# When starting from a checkpoint with an empty block, we'll store the state
# "ahead" of the head slot - this slot would be considered finalized
slot = max(head.slot, (tail.slot.epoch + 1).start_slot)
# To know the finalized checkpoint of the head, we need to recreate its
# state - the tail is implicitly finalized, and if we have a finalized block
# table, that provides another hint
finalizedSlot = db.finalizedBlocks.high.get(tail.slot)
cache: StateCache
foundHeadState = false
headBlocks: seq[BlockRef]
# Load head -> finalized, or all summaries in case the finalized block table
# hasn't been written yet
for blck in db.getAncestorSummaries(head.root):
# The execution block root gets filled in as needed. Nonfinalized Bellatrix
# and later blocks are loaded as optimistic, which gets adjusted that first
# `VALID` fcU from an EL plus markBlockVerified. Pre-merge blocks still get
# marked as `VALID`.
let newRef = BlockRef.init(
blck.root, Opt.none Eth2Digest, executionValid = false,
blck.summary.slot)
if headRef == nil:
headRef = newRef
if curRef != nil:
link(newRef, curRef)
curRef = newRef
dag.forkBlocks.incl(KeyedBlockRef.init(curRef))
if not foundHeadState:
foundHeadState = db.getState(
cfg, blck.root, blck.summary.slot..slot, dag.headState, noRollback)
slot = blck.summary.slot
if not foundHeadState:
# When the database has been written with a pre-fork version of the
# software, it may happen that blocks produced using an "unforked"
# chain get written to the database - we need to skip such blocks
# when loading the database with a fork-compatible version
if containsBlock(cfg, db, curRef.slot, curRef.root):
headBlocks.add curRef
else:
if headBlocks.len > 0:
fatal "Missing block needed to create head state, database corrupt?",
curRef = shortLog(curRef)
quit 1
# Without the block data we can't form a state for this root, so
# we'll need to move the head back
headRef = nil
dag.forkBlocks.excl(KeyedBlockRef.init(curRef))
if curRef.slot <= finalizedSlot:
# Only non-finalized slots get a `BlockRef`
break
let summariesTick = Moment.now()
if not foundHeadState:
if not dag.getStateByParent(curRef.bid, dag.headState):
fatal "Could not load head state, database corrupt?",
head = shortLog(head), tail = shortLog(dag.tail)
quit 1
block:
# EpochRef needs an epoch boundary state
assign(dag.epochRefState, dag.headState)
var info: ForkedEpochInfo
while headBlocks.len > 0:
dag.applyBlock(
dag.headState, headBlocks.pop().bid, cache,
info).expect("head blocks should apply")
dag.head = headRef
dag.heads = @[headRef]
withState(dag.headState):
when consensusFork >= ConsensusFork.Altair:
dag.headSyncCommittees = forkyState.data.get_sync_committee_cache(cache)
assign(dag.clearanceState, dag.headState)
if dag.headState.latest_block_root == tail.root:
# In case we started from a checkpoint with an empty slot
finalizedSlot = getStateField(dag.headState, slot)
finalizedSlot =
max(
finalizedSlot,
getStateField(dag.headState, finalized_checkpoint).epoch.start_slot)
let
configFork = case dag.headState.kind
of ConsensusFork.Phase0: genesisFork(cfg)
of ConsensusFork.Altair: altairFork(cfg)
of ConsensusFork.Bellatrix: bellatrixFork(cfg)
of ConsensusFork.Capella: capellaFork(cfg)
of ConsensusFork.Deneb: denebFork(cfg)
of ConsensusFork.Electra: electraFork(cfg)
stateFork = getStateField(dag.headState, fork)
# Here, we check only the `current_version` field because the spec
# mandates that testnets starting directly from a particular fork
# should have `previous_version` set to `current_version` while
# this doesn't happen to be the case in network that go through
# regular hard-fork upgrades. See for example:
# https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.3/specs/bellatrix/beacon-chain.md#testing
if stateFork.current_version != configFork.current_version:
error "State from database does not match network, check --network parameter",
tail = dag.tail, headRef, stateFork, configFork
quit 1
# Need to load state to find genesis validators root, before loading era db
dag.era = EraDB.new(
cfg, eraPath, getStateField(dag.headState, genesis_validators_root))
# We used an interim finalizedHead while loading the head state above - now
# that we have loaded the dag up to the finalized slot, we can also set
# finalizedHead to its real value
dag.finalizedHead = headRef.atSlot(finalizedSlot)
dag.lastPrunePoint = dag.finalizedHead.toBlockSlotId().expect("not nil")
doAssert dag.finalizedHead.blck != nil,
"The finalized head should exist at the slot"
block: # Top up finalized blocks
if db.finalizedBlocks.high.isNone or
db.finalizedBlocks.high.get() < dag.finalizedHead.blck.slot:
# Versions prior to 1.7.0 did not store finalized blocks in the
# database, and / or the application might have crashed between the head
# and finalized blocks updates.
info "Loading finalized blocks",
finHigh = db.finalizedBlocks.high,
finalizedHead = shortLog(dag.finalizedHead)
var
newFinalized: seq[BlockId]
tmp = dag.finalizedHead.blck
while tmp.parent != nil:
newFinalized.add(tmp.bid)
let p = tmp.parent
tmp.parent = nil
tmp = p
for blck in db.getAncestorSummaries(tmp.root):
if db.finalizedBlocks.high.isSome and
blck.summary.slot <= db.finalizedBlocks.high.get:
break
newFinalized.add(BlockId(slot: blck.summary.slot, root: blck.root))
db.updateFinalizedBlocks(newFinalized)
doAssert dag.finalizedHead.blck.parent == nil,
"The finalized head is the last BlockRef with a parent"
block:
let finalized = db.finalizedBlocks.get(db.finalizedBlocks.high.get()).expect(
"tail at least")
if finalized != dag.finalizedHead.blck.root:
error "Head does not lead to finalized block, database corrupt?",
head = shortLog(head), finalizedHead = shortLog(dag.finalizedHead),
tail = shortLog(dag.tail), finalized = shortLog(finalized)
quit 1
dag.backfill = block:
let backfillSlot = db.finalizedBlocks.low.expect("tail at least")
if backfillSlot <= dag.horizon:
# Backfill done, no need to load anything
BeaconBlockSummary()
elif backfillSlot < dag.tail.slot:
let backfillRoot = db.finalizedBlocks.get(backfillSlot).expect(
"low to be loadable")
db.getBeaconBlockSummary(backfillRoot).expect(
"Backfill block must have a summary: " & $backfillRoot)
elif dag.containsBlock(dag.tail):
db.getBeaconBlockSummary(dag.tail.root).expect(
"Tail block must have a summary: " & $dag.tail.root)
else:
# Checkpoint sync, checkpoint block unavailable
BeaconBlockSummary(
slot: dag.tail.slot + 1,
parent_root: dag.tail.root)
dag.forkDigests = newClone ForkDigests.init(
cfg, getStateField(dag.headState, genesis_validators_root))
withState(dag.headState):
dag.validatorMonitor[].registerState(forkyState.data)
updateBeaconMetrics(dag.headState, dag.head.bid, cache)
let finalizedTick = Moment.now()
if dag.backfill.slot > GENESIS_SLOT: # Try frontfill from era files
let backfillSlot = dag.backfill.slot - 1
dag.frontfillBlocks = newSeqOfCap[Eth2Digest](backfillSlot.int)
let
historical_roots = getStateField(dag.headState, historical_roots).asSeq()
historical_summaries = dag.headState.historical_summaries.asSeq()
var
blocks = 0
# Here, we'll build up the slot->root mapping in memory for the range of
# blocks from genesis to backfill, if possible.
for bid in dag.era.getBlockIds(
historical_roots, historical_summaries, Slot(0), Eth2Digest()):
# If backfill has not yet started, the backfill slot itself also needs
# to be served from era files. Checkpoint sync starts from state only
if bid.slot > backfillSlot or
(bid.slot == backfillSlot and bid.root != dag.tail.root):
# If we end up in here, we failed the root comparison just below in
# an earlier iteration
fatal "Era summaries don't lead up to backfill, database or era files corrupt?",
bid, backfillSlot
quit 1
# In BeaconState.block_roots, empty slots are filled with the root of
# the previous block - in our data structure, we use a zero hash instead
dag.frontfillBlocks.setLen(bid.slot.int + 1)
dag.frontfillBlocks[bid.slot.int] = bid.root
if bid.root == dag.backfill.parent_root:
# We've reached the backfill point, meaning blocks are available
# in the sqlite database from here onwards - remember this point in
# time so that we can write summaries to the database - it's a lot
# faster to load from database than to iterate over era files with
# the current naive era file reader.
reset(dag.backfill)
dag.updateFrontfillBlocks()
break
blocks += 1
if blocks > 0:
info "Front-filled blocks from era files", blocks, backfillSlot
let frontfillTick = Moment.now()
# Fill validator key cache in case we're loading an old database that doesn't
# have a cache
dag.updateValidatorKeys(getStateField(dag.headState, validators).asSeq())
# Initialize pruning such that when starting with a database that hasn't been
# pruned, we work our way from the tail to the horizon in incremental steps
dag.lastHistoryPruneHorizon = dag.horizon()
dag.lastHistoryPruneBlockHorizon = block:
let boundary = min(dag.tail.slot, dag.horizon())
if boundary.epoch() >= EPOCHS_PER_STATE_SNAPSHOT:
start_slot(boundary.epoch() - EPOCHS_PER_STATE_SNAPSHOT)
else:
Slot(0)
info "Block DAG initialized",
head = shortLog(dag.head),
finalizedHead = shortLog(dag.finalizedHead),
tail = shortLog(dag.tail),
backfill = shortLog(dag.backfill),
loadDur = loadTick - startTick,
summariesDur = summariesTick - loadTick,
finalizedDur = finalizedTick - summariesTick,
frontfillDur = frontfillTick - finalizedTick,
keysDur = Moment.now() - frontfillTick
dag.initLightClientDataCache()
dag
template genesis_validators_root*(dag: ChainDAGRef): Eth2Digest =
getStateField(dag.headState, genesis_validators_root)
proc genesisBlockRoot*(dag: ChainDAGRef): Eth2Digest =
dag.db.getGenesisBlock().expect("DB must be initialized with genesis block")
func getEpochRef*(
dag: ChainDAGRef, state: ForkedHashedBeaconState, cache: var StateCache): EpochRef =
## Get a cached `EpochRef` or construct one based on the given state - always
## returns an EpochRef instance
let
bid = state.latest_block_id
epoch = state.get_current_epoch()
dag.findEpochRef(bid, epoch).valueOr:
let res = EpochRef.init(dag, state, cache)
dag.putEpochRef(res)
res
proc getEpochRef*(
dag: ChainDAGRef, bid: BlockId, epoch: Epoch,
preFinalized: bool): Result[EpochRef, cstring] =
## Return a cached EpochRef or construct one from the database, if possible -
## returns `none` on failure.
##
## When `preFinalized` is true, include epochs from before the finalized
## checkpoint in the search - this potentially can result in long processing
## times due to state replays.
##
## Requests for epochs >= dag.finalizedHead.slot.epoch always return an
## instance. One must be careful to avoid race conditions in `async` code
## where the finalized head might change during an `await`.
##
## Requests for epochs < dag.finalizedHead.slot.epoch may fail, either because
## the search was limited by the `preFinalized` flag or because state history
## has been pruned - `none` will be returned in this case.
if not preFinalized and epoch < dag.finalizedHead.slot.epoch:
return err("Requesting pre-finalized EpochRef")
if bid.slot < dag.tail.slot or epoch < dag.tail.slot.epoch:
return err("Requesting EpochRef for pruned state")
let epochRef = dag.findEpochRef(bid, epoch)
if epochRef.isOk():
beacon_state_data_cache_hits.inc
return ok epochRef.get()
beacon_state_data_cache_misses.inc
let
ancestor = dag.epochAncestor(bid, epoch).valueOr:
# If we got in here, the bid must be unknown or we would have gotten
# _some_ ancestor (like the tail)
return err("Requesting EpochRef for non-canonical block")
var cache: StateCache
if not updateState(dag, dag.epochRefState, ancestor, false, cache):
return err("Could not load requested state")
ok(dag.getEpochRef(dag.epochRefState, cache))
proc getEpochRef*(
dag: ChainDAGRef, blck: BlockRef, epoch: Epoch,
preFinalized: bool): Result[EpochRef, cstring] =
dag.getEpochRef(blck.bid, epoch, preFinalized)
proc getFinalizedEpochRef*(dag: ChainDAGRef): EpochRef =
dag.getEpochRef(
dag.finalizedHead.blck, dag.finalizedHead.slot.epoch, false).expect(
"getEpochRef for finalized head should always succeed")
proc ancestorSlot*(
dag: ChainDAGRef, state: ForkyHashedBeaconState, bid: BlockId,
lowSlot: Slot): Opt[Slot] =
## Return common ancestor slot of `bid` and `state`, if at least `lowSlot`.
## Return `none` if no common ancestor is found with slot >= `lowSlot`.
if state.data.slot < lowSlot or bid.slot < lowSlot:
return Opt.none(Slot)
var stateBid = ? dag.getBlockIdAtSlot(state, bid.slot)
if stateBid.slot < lowSlot:
return Opt.none(Slot)
var blockBid = (? dag.atSlot(bid, stateBid.slot)).bid
if blockBid.slot < lowSlot:
return Opt.none(Slot)
while stateBid != blockBid:
if stateBid.slot >= blockBid.slot:
stateBid = ? dag.getBlockIdAtSlot(
state, min(blockBid.slot, stateBid.slot - 1))
if stateBid.slot < lowSlot:
return Opt.none(Slot)
else:
blockBid = ? dag.parent(blockBid)
if blockBid.slot < lowSlot:
return Opt.none(Slot)
Opt.some stateBid.slot
proc computeRandaoMix(
bdata: ForkedTrustedSignedBeaconBlock): Opt[Eth2Digest] =
## Compute the requested RANDAO mix for `bdata` without `state`, if possible.
withBlck(bdata):
when consensusFork >= ConsensusFork.Bellatrix:
if forkyBlck.message.is_execution_block:
var mix = eth2digest(forkyBlck.message.body.randao_reveal.toRaw())
mix.data.mxor forkyBlck.message.body.execution_payload.prev_randao.data
return ok mix
Opt.none(Eth2Digest)
proc computeRandaoMix*(
dag: ChainDAGRef, state: ForkyHashedBeaconState, bid: BlockId,
lowSlot: Slot): Opt[Eth2Digest] =
## Compute the requested RANDAO mix for `bid` based on `state`.
## Return `none` if `state` and `bid` do not share a common ancestor
## with slot >= `lowSlot`.
let ancestorSlot = ? dag.ancestorSlot(state, bid, lowSlot)
doAssert ancestorSlot <= state.data.slot
doAssert ancestorSlot <= bid.slot
# If `blck` is post merge, RANDAO information is immediately available
let
bdata = ? dag.getForkedBlock(bid)
fullMix = computeRandaoMix(bdata)
if fullMix.isSome:
return fullMix
# RANDAO mix has to be recomputed from `bid` and `state`
var mix {.noinit.}: Eth2Digest
proc mixToAncestor(highBid: BlockId): Opt[void] =
## Mix in/out RANDAO reveals back to `ancestorSlot`
var bid = highBid
while bid.slot > ancestorSlot:
let bdata = ? dag.getForkedBlock(bid)
withBlck(bdata): # See `process_randao` / `process_randao_mixes_reset`
mix.data.mxor eth2digest(
forkyBlck.message.body.randao_reveal.toRaw()).data
bid = ? dag.parent(bid)
ok()
# Mix in RANDAO from `bid`
if ancestorSlot < bid.slot:
withBlck(bdata):
mix = eth2digest(forkyBlck.message.body.randao_reveal.toRaw())
? mixToAncestor(? dag.parent(bid))
else:
mix.reset()
# Mix in RANDAO from `state`
let ancestorEpoch = ancestorSlot.epoch
if ancestorEpoch + EPOCHS_PER_HISTORICAL_VECTOR <= state.data.slot.epoch:
return Opt.none(Eth2Digest)
let mixRoot = state.dependent_root(ancestorEpoch + 1)
if mixRoot.isZero:
return Opt.none(Eth2Digest)
? mixToAncestor(? dag.getBlockId(mixRoot))
mix.data.mxor state.data.get_randao_mix(ancestorEpoch).data
ok mix
proc computeRandaoMixFromMemory*(
dag: ChainDAGRef, bid: BlockId, lowSlot: Slot): Opt[Eth2Digest] =
## Compute requested RANDAO mix for `bid` from available states (~5 ms).
template tryWithState(state: ForkedHashedBeaconState) =
block:
withState(state):
let mix = dag.computeRandaoMix(forkyState, bid, lowSlot)
if mix.isSome:
return mix
tryWithState dag.headState
tryWithState dag.epochRefState
tryWithState dag.clearanceState
proc computeRandaoMixFromDatabase*(
dag: ChainDAGRef, bid: BlockId, lowSlot: Slot): Opt[Eth2Digest] =
## Compute requested RANDAO mix for `bid` using closest DB state (~500 ms).
let state = assignClone(dag.headState)
? dag.getNearbyState(state[], bid, lowSlot)
withState(state[]):
dag.computeRandaoMix(forkyState, bid, lowSlot)
proc computeRandaoMix(
dag: ChainDAGRef, bid: BlockId, lowSlot: Slot): Opt[Eth2Digest] =
# Try to compute from states available in memory
let mix = dag.computeRandaoMixFromMemory(bid, lowSlot)
if mix.isSome:
return mix
# If `blck` is post merge, RANDAO information is immediately available
let
bdata = ? dag.getForkedBlock(bid)
fullMix = computeRandaoMix(bdata)
if fullMix.isSome:
return fullMix
# Fall back to database
dag.computeRandaoMixFromDatabase(bid, lowSlot)
proc computeRandaoMix*(dag: ChainDAGRef, bid: BlockId): Opt[Eth2Digest] =
## Compute requested RANDAO mix for `bid`.
const maxSlotDistance = SLOTS_PER_HISTORICAL_ROOT
let lowSlot = max(bid.slot, maxSlotDistance.Slot) - maxSlotDistance
dag.computeRandaoMix(bid, lowSlot)
proc lowSlotForAttesterShuffling*(epoch: Epoch): Slot =
## Return minimum slot that a state must share ancestry with a block history
## so that RANDAO at `epoch.attester_dependent_slot` can be computed.
# A state must be somewhat recent so that `get_active_validator_indices`
# for the queried `epoch` cannot be affected by any such skipped processing.
const numDelayEpochs = compute_activation_exit_epoch(GENESIS_EPOCH).uint64
let lowEpoch = max(epoch, (numDelayEpochs - 1).Epoch) - (numDelayEpochs - 1)
lowEpoch.start_slot
proc computeShufflingRef*(
dag: ChainDAGRef, state: ForkyHashedBeaconState,
blck: BlockRef, epoch: Epoch): Opt[ShufflingRef] =
## Compute `ShufflingRef` for `blck@epoch` based on `state`.
## If `state` has unviable `get_active_validator_indices`, return `none`.
let
dependentBid = (? dag.atSlot(blck.bid, epoch.attester_dependent_slot)).bid
lowSlot = epoch.lowSlotForAttesterShuffling
mix = ? dag.computeRandaoMix(state, dependentBid, lowSlot)
return ok ShufflingRef(
epoch: epoch,
attester_dependent_root: dependentBid.root,
shuffled_active_validator_indices:
state.data.get_shuffled_active_validator_indices(epoch, mix))
proc computeShufflingRefFromMemory*(
dag: ChainDAGRef, blck: BlockRef, epoch: Epoch): Opt[ShufflingRef] =
## Compute `ShufflingRef` from available states (~5 ms).
template tryWithState(state: ForkedHashedBeaconState) =
block:
withState(state):
let shufflingRef = dag.computeShufflingRef(forkyState, blck, epoch)
if shufflingRef.isOk:
return shufflingRef
tryWithState dag.headState
tryWithState dag.epochRefState
tryWithState dag.clearanceState
proc getShufflingRef*(
dag: ChainDAGRef, blck: BlockRef, epoch: Epoch,
preFinalized: bool): Opt[ShufflingRef] =
## Return the shuffling in the given history and epoch - this potentially is
## faster than returning a full EpochRef because the shuffling is determined
## an epoch in advance and therefore is less sensitive to reorgs
var shufflingRef = dag.findShufflingRef(blck.bid, epoch)
if shufflingRef.isSome:
return shufflingRef
# Use existing states to quickly compute the shuffling
shufflingRef = dag.computeShufflingRefFromMemory(blck, epoch)
if shufflingRef.isSome:
dag.putShufflingRef(shufflingRef.get)
return shufflingRef
# Last resort, this can take several seconds as this may replay states
let epochRef = dag.getEpochRef(blck, epoch, preFinalized).valueOr:
return Opt.none ShufflingRef
dag.putShufflingRef(epochRef.shufflingRef)
Opt.some epochRef.shufflingRef
func stateCheckpoint*(dag: ChainDAGRef, bsi: BlockSlotId): BlockSlotId =
## The first ancestor BlockSlot that is a state checkpoint
var bsi = bsi
while not dag.isStateCheckpoint(bsi):
if bsi.isProposed:
bsi.bid = dag.parent(bsi.bid).valueOr:
break
else:
bsi.slot = bsi.slot - 1
bsi
template forkAtEpoch*(dag: ChainDAGRef, epoch: Epoch): Fork =
forkAtEpoch(dag.cfg, epoch)
proc getBlockRange*(
dag: ChainDAGRef, startSlot: Slot, skipStep: uint64,
output: var openArray[BlockId]): Natural =
## This function populates an `output` buffer of blocks
## with a slots ranging from `startSlot` up to, but not including,
## `startSlot + skipStep * output.len`, skipping any slots that don't have
## a block.
##
## Blocks will be written to `output` from the end without gaps, even if
## a block is missing in a particular slot. The return value shows how
## many slots were missing blocks - to iterate over the result, start
## at this index.
##
## If there were no blocks in the range, `output.len` will be returned.
let
requestedCount = output.lenu64
headSlot = dag.head.slot
trace "getBlockRange entered",
head = shortLog(dag.head.root), requestedCount, startSlot, skipStep, headSlot
if startSlot < dag.backfill.slot:
debug "Got request for pre-backfill slot",
startSlot, backfillSlot = dag.backfill.slot, horizonSlot = dag.horizon
return output.len
if headSlot <= startSlot or requestedCount == 0:
return output.len # Identical to returning an empty set of block as indicated above
let
runway = uint64(headSlot - startSlot)
# This is the number of blocks that will follow the start block
extraSlots = min(runway div skipStep, requestedCount - 1)
# If `skipStep` is very large, `extraSlots` should be 0 from
# the previous line, so `endSlot` will be equal to `startSlot`:
endSlot = startSlot + extraSlots * skipStep
var
curSlot = endSlot
o = output.len
# Process all blocks that follow the start block (may be zero blocks)
while curSlot > startSlot:
let bs = dag.getBlockIdAtSlot(curSlot)
if bs.isSome and bs.get().isProposed():
o -= 1
output[o] = bs.get().bid
curSlot -= skipStep
# Handle start slot separately (to avoid underflow when computing curSlot)
let bs = dag.getBlockIdAtSlot(startSlot)
if bs.isSome and bs.get().isProposed():
o -= 1
output[o] = bs.get().bid
o # Return the index of the first non-nil item in the output
proc updateState*(
dag: ChainDAGRef, state: var ForkedHashedBeaconState, bsi: BlockSlotId,
save: bool, cache: var StateCache): bool =
## Rewind or advance state such that it matches the given block and slot -
## this may include replaying from an earlier snapshot if blck is on a
## different branch or has advanced to a higher slot number than slot
## If `bs.slot` is higher than `bs.blck.slot`, `updateState` will fill in
## with empty/non-block slots
# First, see if we're already at the requested block. If we are, also check
# that the state has not been advanced past the desired block - if it has,
# an earlier state must be loaded since there's no way to undo the slot
# transitions
let
startTick = Moment.now()
current {.used.} = withState(state):
BlockSlotId.init(forkyState.latest_block_id, forkyState.data.slot)
var
ancestors: seq[BlockId]
found = false
template exactMatch(state: ForkedHashedBeaconState, bsi: BlockSlotId): bool =
# The block is the same and we're at an early enough slot - the state can
# be used to arrive at the desired blockslot
state.matches_block_slot(bsi.bid.root, bsi.slot)
template canAdvance(state: ForkedHashedBeaconState, bsi: BlockSlotId): bool =
# The block is the same and we're at an early enough slot - the state can
# be used to arrive at the desired blockslot
state.can_advance_slots(bsi.bid.root, bsi.slot)
# Fast path: check all caches for an exact match - this is faster than
# advancing a state where there's epoch processing to do, by a wide margin -
# it also avoids `hash_tree_root` for slot processing
if exactMatch(state, bsi):
found = true
elif not save:
# When required to save states, we cannot rely on the caches because that
# would skip the extra processing that save does - not all information that
# goes into the database is cached
if exactMatch(dag.headState, bsi):
assign(state, dag.headState)
found = true
elif exactMatch(dag.clearanceState, bsi):
assign(state, dag.clearanceState)
found = true
elif exactMatch(dag.epochRefState, bsi):
assign(state, dag.epochRefState)
found = true
const RewindBlockThreshold = 64
if not found:
# No exact match found - see if any in-memory state can be used as a base
# onto which we can apply a few blocks - there's a tradeoff here between
# loading the state from disk and performing the block applications
var cur = bsi
while ancestors.len < RewindBlockThreshold:
if isZero(cur.bid.root): # tail reached
break
if canAdvance(state, cur): # Typical case / fast path when there's no reorg
found = true
break
if not save: # see above
if canAdvance(dag.headState, cur):
assign(state, dag.headState)
found = true
break
if canAdvance(dag.clearanceState, cur):
assign(state, dag.clearanceState)
found = true
break
if canAdvance(dag.epochRefState, cur):
assign(state, dag.epochRefState)
found = true
break
if cur.isProposed():
# This is not an empty slot, so the block will need to be applied to
# eventually reach bs
ancestors.add(cur.bid)
# Move slot by slot to capture epoch boundary states
cur = dag.parentOrSlot(cur).valueOr:
break
if not found:
debug "UpdateStateData cache miss",
current = shortLog(current), target = shortLog(bsi)
# Either the state is too new or was created by applying a different block.
# We'll now resort to loading the state from the database then reapplying
# blocks until we reach the desired point in time.
var cur = bsi
ancestors.setLen(0)
# Look for a state in the database and load it - as long as it cannot be
# found, keep track of the blocks that are needed to reach it from the
# state that eventually will be found.
# If we hit the tail, it means that we've reached a point for which we can
# no longer recreate history - this happens for example when starting from
# a checkpoint block
let startEpoch = bsi.slot.epoch
while not canAdvance(state, cur) and
not dag.db.getState(dag.cfg, cur.bid.root, cur.slot, state, noRollback):
# There's no state saved for this particular BlockSlot combination, and
# the state we have can't trivially be advanced (in case it was older than
# RewindBlockThreshold), keep looking..
if cur.isProposed():
# This is not an empty slot, so the block will need to be applied to
# eventually reach bs
ancestors.add(cur.bid)
if cur.slot == GENESIS_SLOT or (cur.slot < dag.finalizedHead.slot and
cur.slot.epoch + uint64(EPOCHS_PER_STATE_SNAPSHOT) * 2 < startEpoch):
# We've either walked two full state snapshot lengths or hit the tail
# and still can't find a matching state: this can happen when
# starting the node from an arbitrary finalized checkpoint and not
# backfilling the states
notice "Request for pruned historical state",
request = shortLog(bsi), tail = shortLog(dag.tail),
cur = shortLog(cur), finalized = shortLog(dag.finalizedHead)
return false
# Move slot by slot to capture epoch boundary states
cur = dag.parentOrSlot(cur).valueOr:
if not dag.getStateByParent(cur.bid, state):
notice "Request for pruned historical state",
request = shortLog(bsi), tail = shortLog(dag.tail),
cur = shortLog(cur)
return false
break
beacon_state_rewinds.inc()
# Starting state has been assigned, either from memory or database
let
assignTick = Moment.now()
ancestor {.used.} = withState(state):
BlockSlotId.init(forkyState.latest_block_id, forkyState.data.slot)
ancestorRoot {.used.} = getStateRoot(state)
var info: ForkedEpochInfo
# Time to replay all the blocks between then and now
for i in countdown(ancestors.len - 1, 0):
# Because the ancestors are in the database, there's no need to persist them
# again. Also, because we're applying blocks that were loaded from the
# database, we can skip certain checks that have already been performed
# before adding the block to the database.
if (let res = dag.applyBlock(state, ancestors[i], cache, info); res.isErr):
warn "Failed to apply block from database",
blck = shortLog(ancestors[i]),
state_bid = shortLog(state.latest_block_id),
error = res.error()
return false
# ...and make sure to process empty slots as requested
dag.advanceSlots(state, bsi.slot, save, cache, info)
# ...and make sure to load the state cache, if it exists
loadStateCache(dag, cache, bsi.bid, getStateField(state, slot).epoch)
let
assignDur = assignTick - startTick
replayDur = Moment.now() - assignTick
beacon_dag_state_replay_seconds.inc(replayDur.toFloatSeconds)
# TODO https://github.com/status-im/nim-chronicles/issues/108
if (assignDur + replayDur) >= MinSignificantProcessingDuration:
# This might indicate there's a cache that's not in order or a disk that is
# too slow - for now, it's here for investigative purposes and the cutoff
# time might need tuning
info "State replayed",
blocks = ancestors.len,
slots = getStateField(state, slot) - ancestor.slot,
current = shortLog(current),
ancestor = shortLog(ancestor),
target = shortLog(bsi),
ancestorStateRoot = shortLog(ancestorRoot),
targetStateRoot = shortLog(getStateRoot(state)),
found,
assignDur,
replayDur
elif ancestors.len > 0:
debug "State replayed",
blocks = ancestors.len,
slots = getStateField(state, slot) - ancestor.slot,
current = shortLog(current),
ancestor = shortLog(ancestor),
target = shortLog(bsi),
ancestorStateRoot = shortLog(ancestorRoot),
targetStateRoot = shortLog(getStateRoot(state)),
found,
assignDur,
replayDur
else: # Normal case!
trace "State advanced",
blocks = ancestors.len,
slots = getStateField(state, slot) - ancestor.slot,
current = shortLog(current),
ancestor = shortLog(ancestor),
target = shortLog(bsi),
ancestorStateRoot = shortLog(ancestorRoot),
targetStateRoot = shortLog(getStateRoot(state)),
found,
assignDur,
replayDur
true
proc delState(dag: ChainDAGRef, bsi: BlockSlotId) =
# Delete state and mapping for a particular block+slot
if not dag.isStateCheckpoint(bsi):
return # We only ever save epoch states
if (let root = dag.db.getStateRoot(bsi.bid.root, bsi.slot); root.isSome()):
dag.db.withManyWrites:
dag.db.delStateRoot(bsi.bid.root, bsi.slot)
dag.db.delState(
dag.cfg.consensusForkAtEpoch(bsi.slot.epoch), root.get())
proc pruneBlockSlot(dag: ChainDAGRef, bs: BlockSlot) =
# TODO: should we move that disk I/O to `onSlotEnd`
dag.delState(bs.toBlockSlotId().expect("not nil"))
if bs.isProposed():
# Update light client data
dag.deleteLightClientData(bs.blck.bid)
bs.blck.executionValid = true
dag.forkBlocks.excl(KeyedBlockRef.init(bs.blck))
discard dag.db.delBlock(
dag.cfg.consensusForkAtEpoch(bs.blck.slot.epoch), bs.blck.root)
proc pruneBlocksDAG(dag: ChainDAGRef) =
## This prunes the block DAG
## This does NOT prune the cached state checkpoints and EpochRef
## This must be done after a new finalization point is reached
## to invalidate pending blocks or attestations referring
## to a now invalid fork.
##
## This does NOT update the `dag.lastPrunePoint` field.
## as the caches and fork choice can be pruned at a later time.
# Clean up block refs, walking block by block
let startTick = Moment.now()
# Finalization means that we choose a single chain as the canonical one -
# it also means we're no longer interested in any branches from that chain
# up to the finalization point
let hlen = dag.heads.len
for i in 0..<hlen:
let n = hlen - i - 1
let head = dag.heads[n]
if dag.finalizedHead.blck.isAncestorOf(head):
continue
var cur = head.atSlot()
# The block whose parent is nil is the `BlockRef` that's part of the
# canonical chain but has now been finalized - in theory there could be
# states at empty slot iff the fork had epoch-long gaps where the epoch
# transition was not on the canonical chain - these will not properly get
# cleaned up by the current logic - but they should also be rare
# TODO clean up the above as well
doAssert dag.finalizedHead.blck.parent == nil,
"finalizedHead parent should have been pruned from memory already"
while cur.blck.parent != nil:
dag.pruneBlockSlot(cur)
cur = cur.parentOrSlot
dag.heads.del(n)
debug "Pruned the blockchain DAG",
currentCandidateHeads = dag.heads.len,
prunedHeads = hlen - dag.heads.len,
dagPruneDur = Moment.now() - startTick
# https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.3/sync/optimistic.md#helpers
func is_optimistic*(dag: ChainDAGRef, bid: BlockId): bool =
let blck =
if bid.slot <= dag.finalizedHead.slot:
dag.finalizedHead.blck
else:
dag.getBlockRef(bid.root).valueOr:
# The block is part of the DB but is not reachable via `BlockRef`;
# it could have been orphaned or the DB is slightly inconsistent.
# Report it as optimistic until it becomes reachable or gets deleted
return true
not blck.executionValid
proc markBlockVerified*(dag: ChainDAGRef, blck: BlockRef) =
var cur = blck
while true:
cur.executionValid = true
debug "markBlockVerified", blck = shortLog(cur)
if cur.parent.isNil:
break
cur = cur.parent
# Always check at least as far back as the parent so that when a new block
# is added with executionValid already set, it stil sets the ancestors, to
# the next valid in the chain.
if cur.executionValid:
return
iterator syncSubcommittee*(
syncCommittee: openArray[ValidatorIndex],
subcommitteeIdx: SyncSubcommitteeIndex): ValidatorIndex =
var i = subcommitteeIdx.asInt * SYNC_SUBCOMMITTEE_SIZE
let onePastEndIdx = min(syncCommittee.len, i + SYNC_SUBCOMMITTEE_SIZE)
while i < onePastEndIdx:
yield syncCommittee[i]
inc i
iterator syncSubcommitteePairs*(
syncCommittee: openArray[ValidatorIndex],
subcommitteeIdx: SyncSubcommitteeIndex): tuple[validatorIdx: ValidatorIndex,
subcommitteeIdx: int] =
var i = subcommitteeIdx.asInt * SYNC_SUBCOMMITTEE_SIZE
let onePastEndIdx = min(syncCommittee.len, i + SYNC_SUBCOMMITTEE_SIZE)
while i < onePastEndIdx:
yield (syncCommittee[i], i)
inc i
func syncCommitteeParticipants*(dag: ChainDAGRef,
slot: Slot): seq[ValidatorIndex] =
withState(dag.headState):
when consensusFork >= ConsensusFork.Altair:
let
period = sync_committee_period(slot)
curPeriod = sync_committee_period(forkyState.data.slot)
if period == curPeriod:
@(dag.headSyncCommittees.current_sync_committee)
elif period == curPeriod + 1:
@(dag.headSyncCommittees.next_sync_committee)
else: @[]
else:
@[]
func getSubcommitteePositionsAux(
dag: ChainDAGRef,
syncCommittee: openArray[ValidatorIndex],
subcommitteeIdx: SyncSubcommitteeIndex,
validatorIdx: uint64): seq[uint64] =
var pos = 0'u64
for valIdx in syncCommittee.syncSubcommittee(subcommitteeIdx):
if validatorIdx == uint64(valIdx):
result.add pos
inc pos
func getSubcommitteePositions*(
dag: ChainDAGRef,
slot: Slot,
subcommitteeIdx: SyncSubcommitteeIndex,
validatorIdx: uint64): seq[uint64] =
withState(dag.headState):
when consensusFork >= ConsensusFork.Altair:
let
period = sync_committee_period(slot)
curPeriod = sync_committee_period(forkyState.data.slot)
template search(syncCommittee: openArray[ValidatorIndex]): seq[uint64] =
dag.getSubcommitteePositionsAux(
syncCommittee, subcommitteeIdx, validatorIdx)
if period == curPeriod:
search(dag.headSyncCommittees.current_sync_committee)
elif period == curPeriod + 1:
search(dag.headSyncCommittees.next_sync_committee)
else: @[]
else:
@[]
template syncCommitteeParticipants*(
dag: ChainDAGRef,
slot: Slot,
subcommitteeIdx: SyncSubcommitteeIndex): seq[ValidatorIndex] =
toSeq(syncSubcommittee(dag.syncCommitteeParticipants(slot), subcommitteeIdx))
iterator syncCommitteeParticipants*(
dag: ChainDAGRef,
slot: Slot,
subcommitteeIdx: SyncSubcommitteeIndex,
aggregationBits: SyncCommitteeAggregationBits): ValidatorIndex =
for pos, valIdx in dag.syncCommitteeParticipants(slot, subcommitteeIdx):
if pos < aggregationBits.bits and aggregationBits[pos]:
yield valIdx
func needStateCachesAndForkChoicePruning*(dag: ChainDAGRef): bool =
dag.lastPrunePoint != dag.finalizedHead.toBlockSlotId().expect("not nil")
proc pruneStateCachesDAG*(dag: ChainDAGRef) =
## This prunes the cached state checkpoints and EpochRef
## This does NOT prune the state associated with invalidated blocks on a fork
## They are pruned via `pruneBlocksDAG`
##
## This updates the `dag.lastPrunePoint` variable
doAssert dag.needStateCachesAndForkChoicePruning()
let startTick = Moment.now()
block: # Remove states, walking slot by slot
# We remove all state checkpoints that come _before_ the current finalized
# head, as we might frequently be asked to replay states from the
# finalized checkpoint and onwards (for example when validating blocks and
# attestations)
var
finPoint = dag.finalizedHead.toBlockSlotId().expect("not nil")
cur = dag.parentOrSlot(dag.stateCheckpoint(finPoint))
prev = dag.parentOrSlot(dag.stateCheckpoint(dag.lastPrunePoint))
while cur.isSome and prev.isSome and cur.get() != prev.get():
let bs = cur.get()
if not isFinalizedStateSnapshot(bs.slot) and
bs.slot != dag.tail.slot:
dag.delState(bs)
let tmp = cur.get()
cur = dag.parentOrSlot(tmp)
let statePruneTick = Moment.now()
block: # Clean up old EpochRef instances
# After finalization, we can clear up the epoch cache and save memory -
# it will be recomputed if needed
dag.epochRefs.delIt(it.epoch < dag.finalizedHead.slot.epoch)
dag.shufflingRefs.delIt(it.epoch < dag.finalizedHead.slot.epoch)
let epochRefPruneTick = Moment.now()
dag.lastPrunePoint = dag.finalizedHead.toBlockSlotId().expect("not nil")
debug "Pruned the state checkpoints and DAG caches.",
statePruneDur = statePruneTick - startTick,
epochRefPruneDur = epochRefPruneTick - statePruneTick
func pruneStep(horizon, lastHorizon, lastBlockHorizon: Slot):
tuple[stateHorizon, blockHorizon: Slot] =
## Compute a reasonable incremental pruning step considering the current
## horizon, how far the database has been pruned already and where we want the
## tail to be - the return value shows the first state and block that we
## should _keep_ (inclusive).
const SLOTS_PER_STATE_SNAPSHOT =
uint64(EPOCHS_PER_STATE_SNAPSHOT * SLOTS_PER_EPOCH)
let
blockHorizon = block:
let
# Keep up with horizon if it's moving fast, ie if we're syncing
maxSlots = max(horizon - lastHorizon, MAX_SLOTS_PER_PRUNE)
# Move the block horizon cap with a lag so that it moves slot-by-slot
# instead of a big jump every time we prune a state - assuming we
# prune every slot, this makes us prune one slot at a time instead of
# a burst of prunes (as computed by maxSlots) around every snapshot
# change followed by no pruning for the rest of the period
maxBlockHorizon =
if horizon + 1 >= SLOTS_PER_STATE_SNAPSHOT:
horizon + 1 - SLOTS_PER_STATE_SNAPSHOT
else:
Slot(0)
# `lastBlockHorizon` captures the case where we're incrementally
# pruning a database that hasn't been pruned for a while: it's
# initialized to a pre-tail value on startup and moves to approach
# `maxBlockHorizon`.
min(maxBlockHorizon, lastBlockHorizon + maxSlots)
# Round up such that we remove state only once blocks have been removed
stateHorizon =
((blockHorizon + SLOTS_PER_STATE_SNAPSHOT - 1) div
SLOTS_PER_STATE_SNAPSHOT) * SLOTS_PER_STATE_SNAPSHOT
(Slot(stateHorizon), blockHorizon)
proc pruneHistory*(dag: ChainDAGRef, startup = false) =
## Perform an incremental pruning step of the history
if dag.db.db.readOnly:
return
let
horizon = dag.horizon()
(stateHorizon, blockHorizon) = pruneStep(
horizon, dag.lastHistoryPruneHorizon, dag.lastHistoryPruneBlockHorizon)
doAssert blockHorizon <= stateHorizon,
"we must never prune blocks while leaving the state"
debug "Pruning history",
horizon, blockHorizon, stateHorizon,
lastHorizon = dag.lastHistoryPruneHorizon,
lastBlockHorizon = dag.lastHistoryPruneBlockHorizon,
tail = dag.tail, head = dag.head
dag.lastHistoryPruneHorizon = horizon
dag.lastHistoryPruneBlockHorizon = blockHorizon
dag.db.withManyWrites:
if stateHorizon > dag.tail.slot:
# First, we want to see if it's possible to prune any states - we store one
# state every EPOCHS_PER_STATE_SNAPSHOT, so this happens infrequently.
var
cur = dag.getBlockIdAtSlot(stateHorizon)
var first = true
while cur.isSome():
let bs = cur.get()
# We don't delete legacy states because the legacy database is openend
# in read-only and slow to delete from due to its sub-optimal structure
if dag.db.containsState(
dag.cfg, bs.bid.root, bs.slot..bs.slot, legacy = first):
if first:
# We leave the state on the prune horizon intact and update the tail
# to point to this state, indicating the new point in time from
# which we can load states in general.
debug "Updating tail", bs
dag.db.putTailBlock(bs.bid.root)
dag.tail = bs.bid
first = false
else:
debug "Pruning historical state", bs
dag.delState(bs)
elif not bs.isProposed:
trace "Reached already-pruned slot, done pruning states", bs
break
if bs.isProposed:
# We store states either at the same slot at the block (checkpoint) or
# by advancing the slot to the nearest epoch start - check both when
# pruning
cur = dag.parentOrSlot(bs)
elif bs.slot.epoch > EPOCHS_PER_STATE_SNAPSHOT:
# Jump one snapshot interval at a time, but don't prune genesis
cur = dag.getBlockIdAtSlot(start_slot(bs.slot.epoch() - EPOCHS_PER_STATE_SNAPSHOT))
else:
break
# Prune blocks after sanity-checking that we don't prune post-tail blocks -
# this could happen if a state is missing at the expected state horizon and
# would indicate a partially inconsistent database since the base
# invariant is that there exists a state at the snapshot slot - better not
# further mess things up regardless
if blockHorizon > GENESIS_SLOT and blockHorizon <= dag.tail.slot:
var
# Leave the horizon block itself
cur = dag.getBlockIdAtSlot(blockHorizon - 1).map(proc(x: auto): auto = x.bid)
while cur.isSome:
let
bid = cur.get()
fork = dag.cfg.consensusForkAtEpoch(bid.slot.epoch)
if bid.slot == GENESIS_SLOT:
# Leave genesis block for nostalgia and the REST API
break
if not dag.db.delBlock(fork, bid.root):
# Stop at the first gap - this is typically the pruning point of the
# previous call to pruneHistory. An inconsistent DB might have more
# blocks beyond that point but we have no efficient way of detecting
# that.
break
cur = dag.parent(bid)
# TODO There have been varied reports of startup pruning causing long
# startup times - an incremental approach would be needed here also
if false and
startup and
dag.cfg.consensusForkAtEpoch(blockHorizon.epoch) > ConsensusFork.Phase0:
# Once during start, we'll clear all "old fork" data - this ensures we get
# rid of any leftover junk in the tables - we do so after linear pruning
# so as to "mostly" clean up the phase0 tables as well (which cannot be
# pruned easily by fork) - one fork at a time, so as not to take too long
let stateFork = dag.cfg.consensusForkAtEpoch(dag.tail.slot.epoch)
var clearedStates = false
if stateFork > ConsensusFork.Phase0:
for fork in ConsensusFork.Phase0..<stateFork:
if dag.db.clearStates(fork):
clearedStates = true
break
let blockFork = dag.cfg.consensusForkAtEpoch(blockHorizon.epoch)
if not clearedStates and blockFork > ConsensusFork.Phase0:
for fork in ConsensusFork.Phase0..<blockFork:
if dag.db.clearBlocks(fork):
break
proc loadExecutionBlockHash*(
dag: ChainDAGRef, bid: BlockId): Opt[Eth2Digest] =
let blockData = dag.getForkedBlock(bid).valueOr:
# Besides database inconsistency issues, this is hit with checkpoint sync.
# The initial `BlockRef` is creted before the checkpoint block is loaded.
# It is backfilled later, so return `none` and keep retrying.
return Opt.none(Eth2Digest)
withBlck(blockData):
when consensusFork >= ConsensusFork.Bellatrix:
Opt.some forkyBlck.message.body.execution_payload.block_hash
else:
Opt.some ZERO_HASH
proc loadExecutionBlockHash*(
dag: ChainDAGRef, blck: BlockRef): Opt[Eth2Digest] =
if blck.executionBlockHash.isNone:
blck.executionBlockHash = dag.loadExecutionBlockHash(blck.bid)
blck.executionBlockHash
from std/packedsets import PackedSet, incl, items
func getValidatorChangeStatuses(
state: ForkedHashedBeaconState, vis: openArray[ValidatorIndex]):
PackedSet[ValidatorIndex] =
var res: PackedSet[ValidatorIndex]
withState(state):
for vi in vis:
if forkyState.data.validators[vi].withdrawal_credentials.data[0] ==
BLS_WITHDRAWAL_PREFIX:
res.incl vi
res
func checkBlsToExecutionChanges(
state: ForkedHashedBeaconState, vis: PackedSet[ValidatorIndex]): bool =
# Within each fork, BLS_WITHDRAWAL_PREFIX to ETH1_ADDRESS_WITHDRAWAL_PREFIX
# and never ETH1_ADDRESS_WITHDRAWAL_PREFIX to BLS_WITHDRAWAL_PREFIX. Latter
# can still happen via reorgs.
# Cases:
# 1) unchanged (BLS_WITHDRAWAL_PREFIX or ETH1_ADDRESS_WITHDRAWAL_PREFIX) from
# old to new head.
# 2) ETH1_ADDRESS_WITHDRAWAL_PREFIX to BLS_WITHDRAWAL_PREFIX
# 3) BLS_WITHDRAWAL_PREFIX to ETH1_ADDRESS_WITHDRAWAL_PREFIX
#
# Only report (3), i.e. whether there were validator indices with withdrawal
# credentials previously using BLS_WITHDRAWAL_PREFIX now using, instead, the
# ETH1_ADDRESS_WITHDRAWAL_PREFIX prefix indicating a BLS to execution change
# went through.
#
# Since it tracks head, it's possible reorgs trigger reporting the same
# validator indices multiple times; this is fine.
withState(state):
anyIt( vis, forkyState.data.validators[it].has_eth1_withdrawal_credential)
proc updateHead*(
dag: ChainDAGRef, newHead: BlockRef, quarantine: var Quarantine,
knownValidators: openArray[ValidatorIndex]) =
## Update what we consider to be the current head, as given by the fork
## choice.
##
## The choice of head affects the choice of finalization point - the order
## of operations naturally becomes important here - after updating the head,
## blocks that were once considered potential candidates for a tree will
## now fall from grace, or no longer be considered resolved.
doAssert not newHead.isNil()
# Could happen if enough blocks get invalidated and would corrupt database -
# When finalized checkpoint is empty, the slot may also be smaller
doAssert newHead.slot >= dag.finalizedHead.slot or
newHead == dag.finalizedHead.blck
let lastHead = dag.head
logScope:
newHead = shortLog(newHead)
lastHead = shortLog(lastHead)
if lastHead == newHead:
trace "No head block update"
return
if newHead.parent.isNil:
# The new head should always have the finalizedHead as ancestor - thus,
# this should not happen except in a race condition where the selected
# `BlockRef` had its parent set to nil as happens during finalization -
# notably, resetting the head to be the finalizedHead is not allowed
error "Cannot update head to block without parent"
return
let
lastHeadStateRoot = getStateRoot(dag.headState)
lastHeadMergeComplete = dag.headState.is_merge_transition_complete()
lastHeadKind = dag.headState.kind
lastKnownValidatorsChangeStatuses = getValidatorChangeStatuses(
dag.headState, knownValidators)
# Start off by making sure we have the right state - updateState will try
# to use existing in-memory states to make this smooth
var cache: StateCache
if not updateState(
dag, dag.headState, newHead.bid.atSlot(), false, cache):
# Advancing the head state should never fail, given that the tail is
# implicitly finalised, the head is an ancestor of the tail and we always
# store the tail state in the database, as well as every epoch slot state in
# between
fatal "Unable to load head state during head update, database corrupt?",
lastHead = shortLog(lastHead)
quit 1
dag.head = newHead
if dag.headState.is_merge_transition_complete() and not
lastHeadMergeComplete and
dag.vanityLogs.onMergeTransitionBlock != nil:
dag.vanityLogs.onMergeTransitionBlock()
if dag.headState.kind > lastHeadKind:
case dag.headState.kind
of ConsensusFork.Phase0 .. ConsensusFork.Bellatrix:
discard
of ConsensusFork.Capella:
if dag.vanityLogs.onUpgradeToCapella != nil:
dag.vanityLogs.onUpgradeToCapella()
of ConsensusFork.Deneb:
if dag.vanityLogs.onUpgradeToDeneb != nil:
dag.vanityLogs.onUpgradeToDeneb()
of ConsensusFork.Electra:
if dag.vanityLogs.onUpgradeToElectra != nil:
dag.vanityLogs.onUpgradeToElectra()
if dag.vanityLogs.onKnownBlsToExecutionChange != nil and
checkBlsToExecutionChanges(
dag.headState, lastKnownValidatorsChangeStatuses):
dag.vanityLogs.onKnownBlsToExecutionChange()
dag.db.putHeadBlock(newHead.root)
updateBeaconMetrics(dag.headState, dag.head.bid, cache)
withState(dag.headState):
when consensusFork >= ConsensusFork.Altair:
dag.headSyncCommittees = forkyState.data.get_sync_committee_cache(cache)
let
finalized_checkpoint =
getStateField(dag.headState, finalized_checkpoint)
finalizedSlot =
# finalized checkpoint may move back in the head state compared to what
# we've seen in other forks - it does not move back in fork choice
# however, so we'll use the last-known-finalized in that case
max(finalized_checkpoint.epoch.start_slot(), dag.finalizedHead.slot)
finalizedHead = newHead.atSlot(finalizedSlot)
doAssert (not finalizedHead.blck.isNil),
"Block graph should always lead to a finalized block"
# Update light client data
dag.processHeadChangeForLightClient()
let (isAncestor, ancestorDepth) = lastHead.getDepth(newHead)
if not(isAncestor):
notice "Updated head block with chain reorg",
headParent = shortLog(newHead.parent),
stateRoot = shortLog(getStateRoot(dag.headState)),
justified = shortLog(getStateField(
dag.headState, current_justified_checkpoint)),
finalized = shortLog(getStateField(dag.headState, finalized_checkpoint)),
isOptHead = not newHead.executionValid
if not(isNil(dag.onReorgHappened)):
let
# TODO (cheatfate): Proper implementation required
data = ReorgInfoObject.init(dag.head.slot, uint64(ancestorDepth),
lastHead.root, newHead.root,
lastHeadStateRoot,
getStateRoot(dag.headState))
dag.onReorgHappened(data)
# A reasonable criterion for "reorganizations of the chain"
quarantine.clearAfterReorg()
beacon_reorgs_total_total.inc()
beacon_reorgs_total.inc()
else:
debug "Updated head block",
stateRoot = shortLog(getStateRoot(dag.headState)),
justified = shortLog(getStateField(
dag.headState, current_justified_checkpoint)),
finalized = shortLog(getStateField(dag.headState, finalized_checkpoint)),
isOptHead = not newHead.executionValid
if not(isNil(dag.onHeadChanged)):
let
depRoot = withState(dag.headState): forkyState.proposer_dependent_root
prevDepRoot = withState(dag.headState):
forkyState.attester_dependent_root
epochTransition = (finalizedHead != dag.finalizedHead)
# TODO (cheatfate): Proper implementation required
data = HeadChangeInfoObject.init(dag.head.slot, dag.head.root,
getStateRoot(dag.headState),
epochTransition, prevDepRoot,
depRoot)
dag.onHeadChanged(data)
withState(dag.headState):
# Every time the head changes, the "canonical" view of balances and other
# state-related metrics change - notify the validator monitor.
# Doing this update during head update ensures there's a reasonable number
# of such updates happening - at most once per valid block.
dag.validatorMonitor[].registerState(forkyState.data)
if finalizedHead != dag.finalizedHead:
debug "Reached new finalization checkpoint",
stateRoot = shortLog(getStateRoot(dag.headState)),
justified = shortLog(getStateField(
dag.headState, current_justified_checkpoint)),
finalized = shortLog(getStateField(dag.headState, finalized_checkpoint))
let oldFinalizedHead = dag.finalizedHead
block:
# Update `dag.finalizedBlocks` with all newly finalized blocks (those
# newer than the previous finalized head), then update `dag.finalizedHead`
var newFinalized: seq[BlockId]
var tmp = finalizedHead.blck
while not isNil(tmp) and tmp.slot >= dag.finalizedHead.slot:
newFinalized.add(tmp.bid)
if tmp != finalizedHead.blck:
# The newly finalized block itself should remain in here so that fork
# choice still can find it via root
dag.forkBlocks.excl(KeyedBlockRef.init(tmp))
let p = tmp.parent
tmp.parent = nil # Reset all parent links to release memory
tmp = p
dag.finalizedHead = finalizedHead
dag.db.updateFinalizedBlocks(newFinalized)
let oldBlockHash = dag.loadExecutionBlockHash(oldFinalizedHead.blck)
if oldBlockHash.isSome and oldBlockHash.unsafeGet.isZero:
let newBlockHash = dag.loadExecutionBlockHash(dag.finalizedHead.blck)
if newBlockHash.isSome and not newBlockHash.unsafeGet.isZero:
if dag.vanityLogs.onFinalizedMergeTransitionBlock != nil:
dag.vanityLogs.onFinalizedMergeTransitionBlock()
# Pruning the block dag is required every time the finalized head changes
# in order to clear out blocks that are no longer viable and should
# therefore no longer be considered as part of the chain we're following
dag.pruneBlocksDAG()
# Update light client data
dag.processFinalizationForLightClient(oldFinalizedHead)
# Send notification about new finalization point via callback.
if not(isNil(dag.onFinHappened)):
let stateRoot =
if dag.finalizedHead.slot == dag.head.slot: getStateRoot(dag.headState)
elif dag.finalizedHead.slot + SLOTS_PER_HISTORICAL_ROOT > dag.head.slot:
getStateField(dag.headState, state_roots).data[
int(dag.finalizedHead.slot mod SLOTS_PER_HISTORICAL_ROOT)]
else:
Eth2Digest() # The thing that finalized was >8192 blocks old?
# TODO (cheatfate): Proper implementation required
let data = FinalizationInfoObject.init(
dag.finalizedHead.blck.root, stateRoot, dag.finalizedHead.slot.epoch)
dag.onFinHappened(dag, data)
proc isInitialized*(T: type ChainDAGRef, db: BeaconChainDB): Result[void, cstring] =
## Lightweight check to see if it is likely that the given database has been
## initialized
let
tailBlockRoot = db.getTailBlock()
if not tailBlockRoot.isSome():
return err("Tail block root missing")
let
tailBlock = db.getBlockId(tailBlockRoot.get())
if not tailBlock.isSome():
return err("Tail block information missing")
ok()
proc preInit*(
T: type ChainDAGRef, db: BeaconChainDB, state: ForkedHashedBeaconState) =
## Initialize a database using the given state, which potentially may be a
## non-genesis state.
##
## When used with a non-genesis state, the resulting database will not be
## compatible with pre-22.11 versions.
logScope:
stateRoot = $getStateRoot(state)
stateSlot = getStateField(state, slot)
doAssert getStateField(state, slot).is_epoch,
"Can only initialize database from epoch states"
withState(state):
db.putState(forkyState)
if forkyState.data.slot == GENESIS_SLOT:
let blck = get_initial_beacon_block(forkyState)
db.putBlock(blck)
db.putGenesisBlock(blck.root)
db.putHeadBlock(blck.root)
db.putTailBlock(blck.root)
notice "Database initialized from genesis",
blockRoot = $blck.root
else:
let blockRoot = forkyState.latest_block_root()
# We write a summary but not the block contents - these will have to be
# backfilled from the network
db.putBeaconBlockSummary(blockRoot, BeaconBlockSummary(
slot: forkyState.data.latest_block_header.slot,
parent_root: forkyState.data.latest_block_header.parent_root
))
db.putHeadBlock(blockRoot)
db.putTailBlock(blockRoot)
if db.getGenesisBlock().isSome():
notice "Checkpoint written to database", blockRoot = $blockRoot
else:
notice "Database initialized from checkpoint", blockRoot = $blockRoot
proc getProposer*(
dag: ChainDAGRef, head: BlockRef, slot: Slot): Opt[ValidatorIndex] =
let
epochRef = dag.getEpochRef(head.bid, slot.epoch(), false).valueOr:
notice "Cannot load EpochRef for given head", head, slot, error
return Opt.none(ValidatorIndex)
slotInEpoch = slot.since_epoch_start()
let proposer = epochRef.beacon_proposers[slotInEpoch]
if proposer.isSome():
if proposer.get().uint64 >= dag.db.immutableValidators.lenu64():
# Sanity check - it should never happen that the key cache doesn't contain
# a key for the selected proposer - that would mean that we somehow
# created validators in the state without updating the cache!
warn "Proposer key not found",
keys = dag.db.immutableValidators.lenu64(), proposer = proposer.get()
return Opt.none(ValidatorIndex)
proposer
proc getProposalState*(
dag: ChainDAGRef, head: BlockRef, slot: Slot, cache: var StateCache):
Result[ref ForkedHashedBeaconState, cstring] =
## Return a state suitable for making proposals for the given head and slot -
## in particular, the state can be discarded after use and does not have a
## state root set
# Start with the clearance state, since this one typically has been advanced
# and thus has a hot hash tree cache
let state = assignClone(dag.clearanceState)
var
info = ForkedEpochInfo()
if not state[].can_advance_slots(head.root, slot):
# The last state root will be computed as part of block production, so skip
# it now
if not dag.updateState(
state[], head.atSlot(slot - 1).toBlockSlotId().expect("not nil"),
false, cache):
error "Cannot get proposal state - skipping block production, database corrupt?",
head = shortLog(head),
slot
return err("Cannot create proposal state")
else:
loadStateCache(dag, cache, head.bid, slot.epoch)
if getStateField(state[], slot) < slot:
process_slots(
dag.cfg, state[], slot, cache, info,
{skipLastStateRootCalculation}).expect("advancing 1 slot should not fail")
ok state
func aggregateAll*(
dag: ChainDAGRef,
validator_indices: openArray[ValidatorIndex]): Result[CookedPubKey, cstring] =
if validator_indices.len == 0:
# Aggregation spec requires non-empty collection
# - https://tools.ietf.org/html/draft-irtf-cfrg-bls-signature-04
# Consensus specs require at least one attesting index in attestation
# - https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.6/specs/phase0/beacon-chain.md#is_valid_indexed_attestation
return err("aggregate: no attesting keys")
let
firstKey = dag.validatorKey(validator_indices[0]).valueOr:
return err("aggregate: invalid validator index")
var aggregateKey{.noinit.}: AggregatePublicKey
aggregateKey.init(firstKey)
for i in 1 ..< validator_indices.len:
let key = dag.validatorKey(validator_indices[i]).valueOr:
return err("aggregate: invalid validator index")
aggregateKey.aggregate(key)
ok(finish(aggregateKey))
func aggregateAll*(
dag: ChainDAGRef,
validator_indices: openArray[ValidatorIndex|uint64],
bits: BitSeq | BitArray): Result[CookedPubKey, cstring] =
if validator_indices.len() != bits.len():
return err("aggregateAll: mismatch in bits length")
var
aggregateKey{.noinit.}: AggregatePublicKey
inited = false
for i in 0..<bits.len():
if bits[i]:
let key = dag.validatorKey(validator_indices[i]).valueOr:
return err("aggregate: invalid validator index")
if inited:
aggregateKey.aggregate(key)
else:
aggregateKey = AggregatePublicKey.init(key)
inited = true
if not inited:
err("aggregate: no attesting keys")
else:
ok(finish(aggregateKey))
func needsBackfill*(dag: ChainDAGRef): bool =
dag.backfill.slot > dag.horizon
proc rebuildIndex*(dag: ChainDAGRef) =
## After a checkpoint sync, we lack intermediate states to replay from - this
## function rebuilds them so that historical replay can take place again
## TODO the pruning of junk states could be moved to a separate function that
## runs either on startup
# First, we check what states we already have in the database - that allows
# resuming the operation at any time
let
roots = dag.db.loadStateRoots()
historicalRoots = getStateField(dag.headState, historical_roots).asSeq()
historicalSummaries = dag.headState.historical_summaries.asSeq()
var
canonical = newSeq[Eth2Digest](
(dag.finalizedHead.slot.epoch + EPOCHS_PER_STATE_SNAPSHOT - 1) div
EPOCHS_PER_STATE_SNAPSHOT)
# `junk` puts in place some infrastructure to prune unnecessary states - it
# will be more useful in the future as a base for pruning
junk: seq[((Slot, Eth2Digest), Eth2Digest)]
for k, v in roots:
if k[0] >= dag.finalizedHead.slot:
continue # skip newer stuff
if k[0] < dag.backfill.slot:
continue # skip stuff for which we have no blocks
if not isFinalizedStateSnapshot(k[0]):
# `tail` will move at the end of the process, so we won't need any
# intermediate states
junk.add((k, v))
continue # skip non-snapshot slots
if k[0] > 0:
let bs = dag.getBlockIdAtSlot(k[0] - 1)
if bs.isNone or bs.get().bid.root != k[1]:
# remove things that are no longer a canonical part of the chain or
# cannot be reached via a block
junk.add((k, v))
continue
if not dag.db.containsState(dag.cfg.consensusForkAtEpoch(k[0].epoch), v):
continue # If it's not in the database..
canonical[k[0].epoch div EPOCHS_PER_STATE_SNAPSHOT] = v
let
state = (ref ForkedHashedBeaconState)()
var
cache: StateCache
info: ForkedEpochInfo
tailBid: Opt[BlockId]
states: int
# `canonical` holds all slots at which a state is expected to appear, using a
# zero root whenever a particular state is missing - this way, if there's
# partial progress or gaps, they will be dealt with correctly
for i, state_root in canonical.mpairs():
let
slot = Epoch(i * EPOCHS_PER_STATE_SNAPSHOT).start_slot
if slot < dag.backfill.slot:
# TODO if we have era files, we could try to load blocks from them at
# this point
# TODO if we don't do the above, we can of course compute the starting `i`
continue
if tailBid.isNone():
if state_root.isZero:
# If we can find an era file with this state, use it as an alternative
# starting point - ignore failures for now
if dag.era.getState(
historicalRoots, historicalSummaries, slot, state[]).isOk():
state_root = getStateRoot(state[])
withState(state[]): dag.db.putState(forkyState)
tailBid = Opt.some state[].latest_block_id()
else:
if not dag.db.getState(
dag.cfg.consensusForkAtEpoch(slot.epoch), state_root, state[],
noRollback):
fatal "Cannot load state, database corrupt or created for a different network?",
state_root, slot
quit 1
tailBid = Opt.some state[].latest_block_id()
continue
if i == 0 or canonical[i - 1].isZero:
reset(tailBid) # No unbroken history!
continue
if not state_root.isZero:
states += 1
continue
let
startSlot = Epoch((i - 1) * EPOCHS_PER_STATE_SNAPSHOT).start_slot
info "Recreating state snapshot",
slot, startStateRoot = canonical[i - 1], startSlot
if getStateRoot(state[]) != canonical[i - 1]:
if not dag.db.getState(
dag.cfg.consensusForkAtEpoch(startSlot.epoch), canonical[i - 1],
state[], noRollback):
error "Can't load start state, database corrupt?",
startStateRoot = shortLog(canonical[i - 1]), slot = startSlot
return
for slot in startSlot..<startSlot + (EPOCHS_PER_STATE_SNAPSHOT * SLOTS_PER_EPOCH):
let bids = dag.getBlockIdAtSlot(slot).valueOr:
warn "Block id missing, cannot continue - database corrupt?", slot
return
# The slot check is needed to avoid re-applying a block
if bids.isProposed and getStateField(state[], latest_block_header).slot < bids.bid.slot:
let res = dag.applyBlock(state[], bids.bid, cache, info)
if res.isErr:
error "Failed to apply block while building index",
state_bid = shortLog(state[].latest_block_id()),
error = res.error()
return
if slot.is_epoch:
cache.prune(slot.epoch)
process_slots(
dag.cfg, state[], slot, cache, info,
dag.updateFlags).expect("process_slots shouldn't fail when state slot is correct")
withState(state[]):
dag.db.putState(forkyState)
dag.db.checkpoint()
state_root = forkyState.root
# Now that we've found a starting point and topped up with "intermediate"
# states, we can update the tail to start at the starting point of the
# first loadable state
if tailBid.isSome():
dag.tail = tailBid.get()
dag.db.putTailBlock(dag.tail.root)
if junk.len > 0:
info "Dropping redundant states", states, redundant = junk.len
for i in junk:
dag.db.delStateRoot(i[0][1], i[0][0])
dag.db.delState(dag.cfg.consensusForkAtEpoch(i[0][0].epoch), i[1])