nimbus-eth2/beacon_chain/block_pool.nim

249 lines
9.4 KiB
Nim

# beacon_chain
# Copyright (c) 2018-2020 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import
std/[algorithm, sequtils, sets],
extras, beacon_chain_db,
stew/results,
spec/[beaconstate, crypto, datatypes, digest, presets, validator],
block_pools/[block_pools_types, clearance, candidate_chains, quarantine]
export results, block_pools_types
# Block_Pools
# --------------------------------------------
#
# Compatibility shims to minimize PR breakage
# during block_pool refactor
type
BlockPool* = object
quarantine: Quarantine
dag*: CandidateChains
{.push raises: [Defect], inline.}
# Quarantine dispatch
# --------------------------------------------
func checkMissing*(pool: var BlockPool): seq[FetchRecord] =
checkMissing(pool.quarantine)
# CandidateChains
# --------------------------------------------
template tail*(pool: BlockPool): BlockRef =
pool.dag.tail
template heads*(pool: BlockPool): seq[BlockRef] =
pool.dag.heads
template head*(pool: BlockPool): BlockRef =
pool.dag.head
template finalizedHead*(pool: BlockPool): BlockSlot =
pool.dag.finalizedHead
proc addRawBlock*(pool: var BlockPool, signedBlock: SignedBeaconBlock,
onBlockAdded: OnBlockAdded
): Result[BlockRef, BlockError] =
## Add a raw block to the blockpool
## Trigger "callback" on success
## Adding a rawblock might unlock a consequent amount of blocks in quarantine
# TODO: `addRawBlock` is accumulating significant cruft
# and is in dire need of refactoring
# - the ugly `inAdd` field
# - the callback
# - callback may be problematic as it's called in async validator duties
result = addRawBlock(pool.dag, pool.quarantine, signedBlock, onBlockAdded)
export parent # func parent*(bs: BlockSlot): BlockSlot
export isAncestorOf # func isAncestorOf*(a, b: BlockRef): bool
export getAncestorAt # func isAncestorOf*(a, b: BlockRef): bool
export get_ancestor # func get_ancestor*(blck: BlockRef, slot: Slot): BlockRef
export atSlot # func atSlot*(blck: BlockRef, slot: Slot): BlockSlot
proc init*(T: type BlockPool,
preset: RuntimePreset,
db: BeaconChainDB,
updateFlags: UpdateFlags = {}): BlockPool =
result.dag = init(CandidateChains, preset, db, updateFlags)
func addFlags*(pool: BlockPool, flags: UpdateFlags) =
## Add a flag to the block processing
## This is destined for testing to add skipBLSValidation flag
pool.dag.updateFlags.incl flags
export init # func init*(T: type BlockRef, root: Eth2Digest, blck: BeaconBlock): BlockRef
export addFlags
func getRef*(pool: BlockPool, root: Eth2Digest): BlockRef =
## Retrieve a resolved block reference, if available
pool.dag.getRef(root)
func getBlockRange*(
pool: BlockPool, startSlot: Slot, skipStep: Natural,
output: var openArray[BlockRef]): 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.
pool.dag.getBlockRange(startSlot, skipStep, output)
func getBlockBySlot*(pool: BlockPool, slot: Slot): BlockRef =
## Retrieves the first block in the current canonical chain
## with slot number less or equal to `slot`.
pool.dag.getBlockBySlot(slot)
func getBlockByPreciseSlot*(pool: BlockPool, slot: Slot): BlockRef =
## Retrieves a block from the canonical chain with a slot
## number equal to `slot`.
pool.dag.getBlockByPreciseSlot(slot)
proc get*(pool: BlockPool, blck: BlockRef): BlockData =
## Retrieve the associated block body of a block reference
pool.dag.get(blck)
proc get*(pool: BlockPool, root: Eth2Digest): Option[BlockData] =
## Retrieve a resolved block reference and its associated body, if available
pool.dag.get(root)
func getOrResolve*(pool: var BlockPool, root: Eth2Digest): BlockRef =
## Fetch a block ref, or nil if not found (will be added to list of
## blocks-to-resolve)
getOrResolve(pool.dag, pool.quarantine, root)
proc updateHead*(pool: BlockPool, newHead: BlockRef) =
## 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.
updateHead(pool.dag, newHead)
proc addMissing*(pool: var BlockPool, broot: Eth2Digest) {.inline.} =
pool.quarantine.addMissing(broot)
proc isInitialized*(T: type BlockPool, db: BeaconChainDB): bool =
isInitialized(CandidateChains, db)
proc preInit*(
T: type BlockPool, db: BeaconChainDB, state: BeaconState,
signedBlock: SignedBeaconBlock) =
preInit(CandidateChains, db, state, signedBlock)
proc getProposer*(pool: BlockPool, head: BlockRef, slot: Slot):
Option[(ValidatorIndex, ValidatorPubKey)] =
getProposer(pool.dag, head, slot)
# Rewinder / State transitions
# --------------------------------------------
template headState*(pool: BlockPool): StateData =
pool.dag.headState
template tmpState*(pool: BlockPool): StateData =
pool.dag.tmpState
template balanceState*(pool: BlockPool): StateData =
pool.dag.balanceState
template withState*(
pool: BlockPool, cache: var StateData, blockSlot: BlockSlot, body: untyped):
untyped =
## Helper template that updates state to a particular BlockSlot - usage of
## cache is unsafe outside of block.
## TODO async transformations will lead to a race where cache gets updated
## while waiting for future to complete - catch this here somehow?
withState(pool.dag, cache, blockSlot, body)
template withEpochState*(
pool: BlockPool, cache: var StateData, blockSlot: BlockSlot, body: untyped):
untyped =
## Helper template that updates state to a state with an epoch matching the
## epoch of blockSlot. This aims to be at least as fast as withState, quick
## enough to expose to unautheticated, remote use, but trades off that it's
## possible for it to decide that finding a state from a matching epoch may
## provide too expensive for such use cases.
##
## cache is unsafe outside of block.
withEpochState(pool.dag, cache, blockSlot, body)
proc updateStateData*(
pool: BlockPool, state: var StateData, bs: BlockSlot,
matchEpoch: bool = false) =
## 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 slot is higher than blck.slot, replay will fill in with empty/non-block
## slots, else it is ignored
updateStateData(pool.dag, state, bs)
proc loadTailState*(pool: BlockPool): StateData =
loadTailState(pool.dag)
proc isValidBeaconBlock*(
pool: var BlockPool, signed_beacon_block: SignedBeaconBlock,
current_slot: Slot, flags: UpdateFlags): Result[void, BlockError] =
isValidBeaconBlock(
pool.dag, pool.quarantine, signed_beacon_block, current_slot, flags)
# Spec functions implemented based on cached values instead of the full state
func count_active_validators*(epochInfo: EpochRef): uint64 =
epochInfo.shuffled_active_validator_indices.lenu64
func get_committee_count_per_slot*(epochInfo: EpochRef): uint64 =
get_committee_count_per_slot(count_active_validators(epochInfo))
func get_beacon_committee*(
epochRef: EpochRef, slot: Slot, index: CommitteeIndex): seq[ValidatorIndex] =
# Return the beacon committee at ``slot`` for ``index``.
let
committees_per_slot = get_committee_count_per_slot(epochRef)
compute_committee(
epochRef.shuffled_active_validator_indices,
(slot mod SLOTS_PER_EPOCH) * committees_per_slot +
index.uint64,
committees_per_slot * SLOTS_PER_EPOCH
)
# https://github.com/ethereum/eth2.0-specs/blob/v0.12.2/specs/phase0/beacon-chain.md#get_attesting_indices
func get_attesting_indices*(epochRef: EpochRef,
data: AttestationData,
bits: CommitteeValidatorsBits):
HashSet[ValidatorIndex] =
get_attesting_indices(
bits,
get_beacon_committee(epochRef, data.slot, data.index.CommitteeIndex))
# https://github.com/ethereum/eth2.0-specs/blob/v0.12.2/specs/phase0/beacon-chain.md#get_indexed_attestation
func get_indexed_attestation*(epochRef: EpochRef, attestation: Attestation): IndexedAttestation =
# Return the indexed attestation corresponding to ``attestation``.
let
attesting_indices =
get_attesting_indices(
epochRef, attestation.data, attestation.aggregation_bits)
IndexedAttestation(
attesting_indices:
List[uint64, Limit MAX_VALIDATORS_PER_COMMITTEE].init(
sorted(mapIt(attesting_indices, it.uint64), system.cmp)),
data: attestation.data,
signature: attestation.signature
)