831 lines
32 KiB
Nim
831 lines
32 KiB
Nim
# beacon_chain
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# Copyright (c) 2022 Status Research & Development GmbH
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# Licensed and distributed under either of
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# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
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# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
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# at your option. This file may not be copied, modified, or distributed except according to those terms.
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{.push raises: [Defect].}
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# This implements the pre-release proposal of the libp2p based light client sync
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# protocol. See https://github.com/ethereum/consensus-specs/pull/2802
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import
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# Status libraries
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stew/[bitops2, objects],
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chronos,
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# Beacon chain internals
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../spec/datatypes/[phase0, altair, bellatrix],
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"."/[block_pools_types, blockchain_dag]
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logScope: topics = "chaindag"
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type
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HashedBeaconStateWithSyncCommittee =
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bellatrix.HashedBeaconState |
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altair.HashedBeaconState
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TrustedSignedBeaconBlockWithSyncAggregate =
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bellatrix.TrustedSignedBeaconBlock |
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altair.TrustedSignedBeaconBlock
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template nextEpochBoundarySlot(slot: Slot): Slot =
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## Compute the first possible epoch boundary state slot of a `Checkpoint`
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## referring to a block at given slot.
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(slot + (SLOTS_PER_EPOCH - 1)).epoch.start_slot
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func computeEarliestLightClientSlot*(dag: ChainDAGRef): Slot =
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## Compute the earliest slot for which light client data is retained.
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let
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minSupportedSlot = max(
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dag.cfg.ALTAIR_FORK_EPOCH.start_slot,
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dag.lightClientCache.importTailSlot)
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currentSlot = getStateField(dag.headState, slot)
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if currentSlot < minSupportedSlot:
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return minSupportedSlot
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let
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MIN_EPOCHS_FOR_BLOCK_REQUESTS =
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dag.cfg.MIN_VALIDATOR_WITHDRAWABILITY_DELAY +
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dag.cfg.CHURN_LIMIT_QUOTIENT div 2
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MIN_SLOTS_FOR_BLOCK_REQUESTS =
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MIN_EPOCHS_FOR_BLOCK_REQUESTS * SLOTS_PER_EPOCH
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if currentSlot - minSupportedSlot < MIN_SLOTS_FOR_BLOCK_REQUESTS:
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return minSupportedSlot
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let earliestSlot = currentSlot - MIN_SLOTS_FOR_BLOCK_REQUESTS
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max(earliestSlot.sync_committee_period.start_slot, minSupportedSlot)
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proc updateExistingState(
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dag: ChainDAGRef, state: var ForkedHashedBeaconState, bsi: BlockSlotId,
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save: bool, cache: var StateCache): bool =
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## Wrapper around `updateState` for states expected to exist.
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let ok = dag.updateState(state, bsi, save, cache)
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if not ok:
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error "State failed to load unexpectedly", bsi, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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ok
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template withUpdatedExistingState(
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dag: ChainDAGRef, state: var ForkedHashedBeaconState,
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bsiParam: BlockSlotId, okBody: untyped, failureBody: untyped): untyped =
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## Wrapper around `withUpdatedState` for states expected to exist.
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block:
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let bsi = bsiParam
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dag.withUpdatedState(state, bsiParam) do:
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okBody
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do:
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error "State failed to load unexpectedly", bsi, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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failureBody
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proc getExistingBlockIdAtSlot(dag: ChainDAGRef, slot: Slot): Opt[BlockSlotId] =
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## Wrapper around `getBlockIdAtSlot` for blocks expected to exist.
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let bsi = dag.getBlockIdAtSlot(slot)
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if bsi.isErr:
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error "Block failed to load unexpectedly", slot, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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bsi
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proc existingParent(dag: ChainDAGRef, bid: BlockId): Opt[BlockId] =
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## Wrapper around `parent` for parents known to exist.
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let parent = dag.parent(bid)
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if parent.isErr:
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error "Parent failed to load unexpectedly", bid, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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parent
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proc getExistingForkedBlock(dag: ChainDAGRef, root: Eth2Digest):
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Opt[ForkedTrustedSignedBeaconBlock] =
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## Wrapper around `getForkedBlock` for blocks expected to exist.
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let bdata = dag.getForkedBlock(root)
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if bdata.isErr:
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error "Block failed to load unexpectedly", root, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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bdata
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proc getExistingForkedBlock*(
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dag: ChainDAGRef, bid: BlockId): Opt[ForkedTrustedSignedBeaconBlock] =
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## Wrapper around `getForkedBlock` for blocks expected to exist.
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let bdata = dag.getForkedBlock(bid)
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if bdata.isErr:
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error "Block failed to load unexpectedly", bid, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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bdata
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proc existingCurrentSyncCommitteeForPeriod(
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dag: ChainDAGRef,
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tmpState: var ForkedHashedBeaconState,
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period: SyncCommitteePeriod): Opt[SyncCommittee] =
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## Wrapper around `currentSyncCommitteeForPeriod` for states known to exist.
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let syncCommittee = dag.currentSyncCommitteeForPeriod(tmpState, period)
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if syncCommittee.isErr:
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error "Current sync committee failed to load unexpectedly",
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period, tail = dag.tail.slot
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doAssert verifyFinalization notin dag.updateFlags
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syncCommittee
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template syncCommitteeRoot(
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state: HashedBeaconStateWithSyncCommittee): Eth2Digest =
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## Compute a root to uniquely identify `current_sync_committee` and
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## `next_sync_committee`.
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withEth2Hash:
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h.update state.data.current_sync_committee.hash_tree_root().data
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h.update state.data.next_sync_committee.hash_tree_root().data
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proc syncCommitteeRootForPeriod(
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dag: ChainDAGRef,
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tmpState: var ForkedHashedBeaconState,
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period: SyncCommitteePeriod): Opt[Eth2Digest] =
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## Compute a root to uniquely identify `current_sync_committee` and
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## `next_sync_committee` for a given sync committee period.
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## For non-finalized periods, follow the chain as selected by fork choice.
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let earliestSlot = dag.computeEarliestLightClientSlot
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doAssert period >= earliestSlot.sync_committee_period
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let
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periodStartSlot = period.start_slot
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syncCommitteeSlot = max(periodStartSlot, earliestSlot)
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bsi = ? dag.getExistingBlockIdAtSlot(syncCommitteeSlot)
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dag.withUpdatedExistingState(tmpState, bsi) do:
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withState(state):
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when stateFork >= BeaconStateFork.Altair:
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ok state.syncCommitteeRoot
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else: raiseAssert "Unreachable"
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do: err()
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proc getLightClientData(
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dag: ChainDAGRef,
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bid: BlockId): CachedLightClientData =
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## Fetch cached light client data about a given block.
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## Data must be cached (`cacheLightClientData`) before calling this function.
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try: dag.lightClientCache.data[bid]
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except KeyError: raiseAssert "Unreachable"
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proc cacheLightClientData*(
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dag: ChainDAGRef,
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state: HashedBeaconStateWithSyncCommittee,
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blck: TrustedSignedBeaconBlockWithSyncAggregate) =
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## Cache data for a given block and its post-state to speed up creating future
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## `LightClientUpdate` and `LightClientBootstrap` instances that refer to this
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## block and state.
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let bid = BlockId(root: blck.root, slot: blck.message.slot)
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var cachedData {.noinit.}: CachedLightClientData
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state.data.build_proof(
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altair.CURRENT_SYNC_COMMITTEE_INDEX,
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cachedData.current_sync_committee_branch)
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state.data.build_proof(
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altair.NEXT_SYNC_COMMITTEE_INDEX,
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cachedData.next_sync_committee_branch)
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cachedData.finalized_slot =
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state.data.finalized_checkpoint.epoch.start_slot
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state.data.build_proof(
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altair.FINALIZED_ROOT_INDEX,
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cachedData.finality_branch)
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if dag.lightClientCache.data.hasKeyOrPut(bid, cachedData):
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doAssert false, "Redundant `cacheLightClientData` call"
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proc deleteLightClientData*(dag: ChainDAGRef, bid: BlockId) =
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## Delete cached light client data for a given block. This needs to be called
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## when a block becomes unreachable due to finalization of a different fork.
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if dag.importLightClientData == ImportLightClientData.None:
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return
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dag.lightClientCache.data.del bid
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template lazy_header(name: untyped): untyped {.dirty.} =
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## `createLightClientUpdates` helper to lazily load a known block header.
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var `name ptr`: ptr[BeaconBlockHeader]
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template `assign _ name`(target: var BeaconBlockHeader,
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bid: BlockId): bool =
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if `name ptr` != nil:
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target = `name ptr`[]
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true
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else:
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let bdata = dag.getExistingForkedBlock(bid)
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if bdata.isOk:
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target = bdata.get.toBeaconBlockHeader
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`name ptr` = addr target
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bdata.isOk
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template lazy_data(name: untyped): untyped {.dirty.} =
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## `createLightClientUpdates` helper to lazily load cached light client state.
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var `name` {.noinit.}: CachedLightClientData
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`name`.finalized_slot = FAR_FUTURE_SLOT
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template `load _ name`(bid: BlockId) =
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if `name`.finalized_slot == FAR_FUTURE_SLOT:
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`name` = dag.getLightClientData(bid)
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template lazy_bid(name: untyped): untyped {.dirty.} =
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## `createLightClientUpdates` helper to lazily load a block id.
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var
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`name` = BlockId(slot: FAR_FUTURE_SLOT)
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`name _ ok` = true
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template `load _ name`(slot: Slot): bool =
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if `name _ ok` and `name`.slot == FAR_FUTURE_SLOT:
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let bsi = dag.getBlockIdAtSlot(slot)
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if bsi.isErr:
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`name _ ok` = false
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else:
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`name` = bsi.get.bid
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`name _ ok`
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proc createLightClientUpdates(
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dag: ChainDAGRef,
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state: HashedBeaconStateWithSyncCommittee,
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blck: TrustedSignedBeaconBlockWithSyncAggregate,
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parent_bid: BlockId) =
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## Create `LightClientUpdate` instances for a given block and its post-state,
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## and keep track of best / latest ones. Data about the parent block's
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## post-state must be cached (`cacheLightClientData`) before calling this.
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# Verify sync committee has sufficient participants
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template sync_aggregate(): auto = blck.message.body.sync_aggregate
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template sync_committee_bits(): auto = sync_aggregate.sync_committee_bits
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let num_active_participants = countOnes(sync_committee_bits).uint64
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if num_active_participants < MIN_SYNC_COMMITTEE_PARTICIPANTS:
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return
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# Verify attested block (parent) is recent enough and that state is available
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template attested_bid(): auto = parent_bid
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let
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earliest_slot = dag.computeEarliestLightClientSlot
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attested_slot = attested_bid.slot
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if attested_slot < earliest_slot:
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return
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# Lazy variables to hold historic data
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lazy_header(attested_header)
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lazy_data(attested_data)
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lazy_bid(finalized_bid)
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lazy_header(finalized_header)
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# Update latest light client data
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template latest(): auto = dag.lightClientCache.latest
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var
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newFinality = false
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newOptimistic = false
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let
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signature_slot = blck.message.slot
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is_later =
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if attested_slot != latest.attested_header.slot:
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attested_slot > latest.attested_header.slot
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else:
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signature_slot > latest.signature_slot
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if is_later and latest.attested_header.assign_attested_header(attested_bid):
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load_attested_data(attested_bid)
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let finalized_slot = attested_data.finalized_slot
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if finalized_slot == latest.finalized_header.slot:
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latest.finality_branch = attested_data.finality_branch
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elif finalized_slot == GENESIS_SLOT:
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latest.finalized_header.reset()
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latest.finality_branch = attested_data.finality_branch
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elif load_finalized_bid(finalized_slot) and
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latest.finalized_header.assign_finalized_header(finalized_bid):
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latest.finality_branch = attested_data.finality_branch
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newFinality = true
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else:
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latest.finalized_header.reset()
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latest.finality_branch.reset()
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latest.sync_aggregate = isomorphicCast[SyncAggregate](sync_aggregate)
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latest.signature_slot = signature_slot
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newOptimistic = true
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# Track best light client data for current period
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let
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attested_period = attested_slot.sync_committee_period
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signature_period = signature_slot.sync_committee_period
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if attested_period == signature_period:
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template next_sync_committee(): auto = state.data.next_sync_committee
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let isNextSyncCommitteeFinalized =
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attested_period.start_slot <= dag.finalizedHead.slot
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var best =
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if isNextSyncCommitteeFinalized:
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dag.lightClientCache.best.getOrDefault(attested_period)
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else:
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let key = (attested_period, state.syncCommitteeRoot)
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dag.lightClientCache.pendingBest.getOrDefault(key)
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load_attested_data(attested_bid)
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let
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finalized_slot = attested_data.finalized_slot
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meta = LightClientUpdateMetadata(
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attested_slot: attested_slot,
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finalized_slot: finalized_slot,
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signature_slot: signature_slot,
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has_sync_committee: true,
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has_finality: load_finalized_bid(finalized_slot),
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num_active_participants: num_active_participants)
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is_better = is_better_data(meta, best.toMeta)
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if is_better and best.attested_header.assign_attested_header(attested_bid):
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best.next_sync_committee = next_sync_committee
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best.next_sync_committee_branch = attested_data.next_sync_committee_branch
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if finalized_slot == best.finalized_header.slot:
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best.finality_branch = attested_data.finality_branch
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elif finalized_slot == GENESIS_SLOT:
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best.finalized_header.reset()
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best.finality_branch = attested_data.finality_branch
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elif meta.has_finality and
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best.finalized_header.assign_finalized_header(finalized_bid):
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best.finality_branch = attested_data.finality_branch
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else:
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best.finalized_header.reset()
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best.finality_branch.reset()
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best.sync_aggregate = isomorphicCast[SyncAggregate](sync_aggregate)
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best.signature_slot = signature_slot
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if isNextSyncCommitteeFinalized:
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dag.lightClientCache.best[attested_period] = best
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debug "Best update for period improved",
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period = attested_period, update = best
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else:
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let key = (attested_period, state.syncCommitteeRoot)
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dag.lightClientCache.pendingBest[key] = best
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debug "Best update for period improved",
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period = key, update = best
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if newFinality and dag.onLightClientFinalityUpdate != nil:
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dag.onLightClientFinalityUpdate(latest)
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if newOptimistic and dag.onLightClientOptimisticUpdate != nil:
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dag.onLightClientOptimisticUpdate(latest.toOptimistic)
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proc processNewBlockForLightClient*(
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dag: ChainDAGRef,
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state: ForkedHashedBeaconState,
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signedBlock: ForkyTrustedSignedBeaconBlock,
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parentBid: BlockId) =
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## Update light client data with information from a new block.
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if dag.importLightClientData == ImportLightClientData.None:
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return
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if signedBlock.message.slot < dag.computeEarliestLightClientSlot:
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return
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when signedBlock is bellatrix.TrustedSignedBeaconBlock:
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dag.cacheLightClientData(state.bellatrixData, signedBlock)
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dag.createLightClientUpdates(state.bellatrixData, signedBlock, parentBid)
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elif signedBlock is altair.TrustedSignedBeaconBlock:
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dag.cacheLightClientData(state.altairData, signedBlock)
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dag.createLightClientUpdates(state.altairData, signedBlock, parentBid)
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elif signedBlock is phase0.TrustedSignedBeaconBlock:
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raiseAssert "Unreachable" # `earliestSlot` cannot be before Altair
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else:
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{.error: "Unreachable".}
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proc processHeadChangeForLightClient*(dag: ChainDAGRef) =
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## Update light client data to account for a new head block.
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## Note that `dag.finalizedHead` is not yet updated when this is called.
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if dag.importLightClientData == ImportLightClientData.None:
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return
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if dag.head.slot < dag.computeEarliestLightClientSlot:
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return
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# Update `best` from `pendingBest` to ensure light client data
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# only refers to sync committees as selected by fork choice
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let headPeriod = dag.head.slot.sync_committee_period
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if headPeriod.start_slot > dag.finalizedHead.slot:
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let finalizedPeriod = dag.finalizedHead.slot.sync_committee_period
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if headPeriod > finalizedPeriod + 1:
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var tmpState = assignClone(dag.headState)
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for period in finalizedPeriod + 1 ..< headPeriod:
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let
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syncCommitteeRoot =
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dag.syncCommitteeRootForPeriod(tmpState[], period).valueOr:
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continue
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key = (period, syncCommitteeRoot)
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dag.lightClientCache.best[period] =
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dag.lightClientCache.pendingBest.getOrDefault(key)
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withState(dag.headState):
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when stateFork >= BeaconStateFork.Altair:
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let key = (headPeriod, state.syncCommitteeRoot)
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dag.lightClientCache.best[headPeriod] =
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dag.lightClientCache.pendingBest.getOrDefault(key)
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else: raiseAssert "Unreachable"
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proc processFinalizationForLightClient*(
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dag: ChainDAGRef, oldFinalizedHead: BlockSlot) =
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## Prune cached data that is no longer useful for creating future
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## `LightClientUpdate` and `LightClientBootstrap` instances.
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## This needs to be called whenever `finalized_checkpoint` changes.
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if dag.importLightClientData == ImportLightClientData.None:
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return
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let
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earliestSlot = dag.computeEarliestLightClientSlot
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finalizedSlot = dag.finalizedHead.slot
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if finalizedSlot < earliestSlot:
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return
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# Cache `LightClientBootstrap` for newly finalized epoch boundary blocks
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let lowSlot = max(oldFinalizedHead.slot + 1, earliestSlot)
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var boundarySlot = finalizedSlot
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while boundarySlot >= lowSlot:
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let
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bsi = dag.getExistingBlockIdAtSlot(boundarySlot).valueOr:
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break
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bid = bsi.bid
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if bid.slot >= lowSlot:
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dag.lightClientCache.bootstrap[bid.slot] =
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CachedLightClientBootstrap(
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current_sync_committee_branch:
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dag.getLightClientData(bid).current_sync_committee_branch)
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boundarySlot = bid.slot.nextEpochBoundarySlot
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if boundarySlot < SLOTS_PER_EPOCH:
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break
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boundarySlot -= SLOTS_PER_EPOCH
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# Prune light client data that is no longer referrable by future updates
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var bidsToDelete: seq[BlockId]
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for bid, data in dag.lightClientCache.data:
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if bid.slot >= finalizedSlot:
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continue
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bidsToDelete.add bid
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for bid in bidsToDelete:
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dag.lightClientCache.data.del bid
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# Prune bootstrap data that is no longer relevant
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var slotsToDelete: seq[Slot]
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for slot in dag.lightClientCache.bootstrap.keys:
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if slot < earliestSlot:
|
|
slotsToDelete.add slot
|
|
for slot in slotsToDelete:
|
|
dag.lightClientCache.bootstrap.del slot
|
|
|
|
# Prune best `LightClientUpdate` that are no longer relevant
|
|
let earliestPeriod = earliestSlot.sync_committee_period
|
|
var periodsToDelete: seq[SyncCommitteePeriod]
|
|
for period in dag.lightClientCache.best.keys:
|
|
if period < earliestPeriod:
|
|
periodsToDelete.add period
|
|
for period in periodsToDelete:
|
|
dag.lightClientCache.best.del period
|
|
|
|
# Prune best `LightClientUpdate` referring to non-finalized sync committees
|
|
# that are no longer relevant, i.e., orphaned or too old
|
|
let finalizedPeriod = finalizedSlot.sync_committee_period
|
|
var keysToDelete: seq[(SyncCommitteePeriod, Eth2Digest)]
|
|
for (period, committeeRoot) in dag.lightClientCache.pendingBest.keys:
|
|
if period <= finalizedPeriod:
|
|
keysToDelete.add (period, committeeRoot)
|
|
for key in keysToDelete:
|
|
dag.lightClientCache.pendingBest.del key
|
|
|
|
proc initLightClientBootstrapForPeriod(
|
|
dag: ChainDAGRef,
|
|
period: SyncCommitteePeriod) =
|
|
## Compute and cache `LightClientBootstrap` data for all finalized
|
|
## epoch boundary blocks within a given sync committee period.
|
|
let periodStartSlot = period.start_slot
|
|
if periodStartSlot > dag.finalizedHead.slot:
|
|
return
|
|
let
|
|
earliestSlot = dag.computeEarliestLightClientSlot
|
|
periodEndSlot = periodStartSlot + SLOTS_PER_SYNC_COMMITTEE_PERIOD - 1
|
|
if periodEndSlot < earliestSlot:
|
|
return
|
|
|
|
let startTick = Moment.now()
|
|
debug "Caching bootstrap data for period", period
|
|
defer:
|
|
let endTick = Moment.now()
|
|
debug "Bootstrap data for period cached", period,
|
|
cacheDur = endTick - startTick
|
|
|
|
let
|
|
lowSlot = max(periodStartSlot, earliestSlot)
|
|
highSlot = min(periodEndSlot, dag.finalizedHead.blck.slot)
|
|
lowBoundarySlot = lowSlot.nextEpochBoundarySlot
|
|
highBoundarySlot = highSlot.nextEpochBoundarySlot
|
|
var
|
|
tmpState = assignClone(dag.headState)
|
|
tmpCache: StateCache
|
|
nextBoundarySlot = lowBoundarySlot
|
|
while nextBoundarySlot <= highBoundarySlot:
|
|
defer: nextBoundarySlot += SLOTS_PER_EPOCH
|
|
let
|
|
bsi = dag.getExistingBlockIdAtSlot(nextBoundarySlot).valueOr:
|
|
continue
|
|
bid = bsi.bid
|
|
boundarySlot = bid.slot.nextEpochBoundarySlot
|
|
if boundarySlot == nextBoundarySlot and bid.slot >= lowSlot and
|
|
not dag.lightClientCache.bootstrap.hasKey(bid.slot):
|
|
var cachedBootstrap {.noinit.}: CachedLightClientBootstrap
|
|
if not dag.updateExistingState(
|
|
tmpState[], bid.atSlot, save = false, tmpCache):
|
|
continue
|
|
withStateVars(tmpState[]):
|
|
withState(state):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
state.data.build_proof(
|
|
altair.CURRENT_SYNC_COMMITTEE_INDEX,
|
|
cachedBootstrap.current_sync_committee_branch)
|
|
else: raiseAssert "Unreachable"
|
|
dag.lightClientCache.bootstrap[bid.slot] = cachedBootstrap
|
|
|
|
proc initLightClientUpdateForPeriod(
|
|
dag: ChainDAGRef, period: SyncCommitteePeriod) =
|
|
## Compute and cache the best `LightClientUpdate` within a given
|
|
## sync committee period up through the finalized head block.
|
|
## Non-finalized blocks are processed incrementally.
|
|
let periodStartSlot = period.start_slot
|
|
if periodStartSlot > dag.finalizedHead.slot:
|
|
return
|
|
let
|
|
earliestSlot = dag.computeEarliestLightClientSlot
|
|
periodEndSlot = periodStartSlot + SLOTS_PER_SYNC_COMMITTEE_PERIOD - 1
|
|
if periodEndSlot < earliestSlot:
|
|
return
|
|
if dag.lightClientCache.best.hasKey(period):
|
|
return
|
|
let startTick = Moment.now()
|
|
debug "Computing best update for period", period
|
|
proc logBest(endTick = Moment.now()) =
|
|
# Using a helper function reduces code size as the `defer` beneath is
|
|
# replicated on every `return`, and the log statement allocates another
|
|
# copy of the arguments on the stack for each instantiation (~1 MB stack!)
|
|
debug "Best update for period computed",
|
|
period, update = dag.lightClientCache.best.getOrDefault(period),
|
|
computeDur = endTick - startTick
|
|
defer: logBest()
|
|
|
|
proc maxParticipantsBlock(
|
|
dag: ChainDAGRef, highBid: BlockId, lowSlot: Slot): Opt[BlockId] =
|
|
## Determine the earliest block with most sync committee signatures among
|
|
## ancestors of `highBid` with at least `lowSlot` as parent block slot.
|
|
## Return `err` if no block with `MIN_SYNC_COMMITTEE_PARTICIPANTS` exists.
|
|
var
|
|
maxParticipants = MIN_SYNC_COMMITTEE_PARTICIPANTS
|
|
maxBid: Opt[BlockId]
|
|
bid = highBid
|
|
while true:
|
|
let parentBid = dag.parent(bid).valueOr:
|
|
break
|
|
if parentBid.slot < lowSlot:
|
|
break
|
|
let
|
|
bdata = dag.getExistingForkedBlock(bid).valueOr:
|
|
break
|
|
numParticipants =
|
|
withBlck(bdata):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
countOnes(blck.message.body.sync_aggregate.sync_committee_bits)
|
|
else: raiseAssert "Unreachable"
|
|
if numParticipants >= maxParticipants:
|
|
maxParticipants = numParticipants
|
|
maxBid = ok bid
|
|
bid = parentBid
|
|
maxBid
|
|
|
|
# Determine the block in the period with highest sync committee participation
|
|
let
|
|
lowSlot = max(periodStartSlot, earliestSlot)
|
|
highSlot = min(periodEndSlot, dag.finalizedHead.blck.slot)
|
|
highBsi = dag.getExistingBlockIdAtSlot(highSlot).valueOr:
|
|
return
|
|
highBid = highBsi.bid
|
|
maxParticipantsBid = dag.maxParticipantsBlock(highBid, lowSlot).valueOr:
|
|
dag.lightClientCache.best[period] =
|
|
default(altair.LightClientUpdate)
|
|
return
|
|
|
|
# The block with highest participation may refer to a `finalized_checkpoint`
|
|
# in a different sync committee period. If that is the case, search for a
|
|
# later block with a `finalized_checkpoint` within the given sync committee
|
|
# period, despite it having a lower sync committee participation
|
|
var
|
|
tmpState = assignClone(dag.headState)
|
|
signatureBid = BlockId(slot: FAR_FUTURE_SLOT)
|
|
finalizedBid = BlockId(slot: FAR_FUTURE_SLOT)
|
|
while true:
|
|
if signatureBid.slot == FAR_FUTURE_SLOT:
|
|
signatureBid = maxParticipantsBid
|
|
else:
|
|
let nextLowSlot = signatureBid.slot + 1
|
|
signatureBid = dag.maxParticipantsBlock(highBid, nextLowSlot).valueOr:
|
|
signatureBid = maxParticipantsBid
|
|
break
|
|
let
|
|
attestedBid = dag.existingParent(signatureBid).valueOr:
|
|
continue
|
|
finalizedEpoch = block:
|
|
dag.withUpdatedExistingState(tmpState[], attestedBid.atSlot) do:
|
|
withState(state):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
state.data.finalized_checkpoint.epoch
|
|
else: raiseAssert "Unreachable"
|
|
do: continue
|
|
finalizedSlot = finalizedEpoch.start_slot
|
|
finalizedBsi = dag.getBlockIdAtSlot(finalizedSlot).valueOr:
|
|
continue
|
|
if finalizedBid.slot >= lowSlot:
|
|
finalizedBid = finalizedBsi.bid
|
|
break
|
|
if signatureBid == maxParticipantsBid:
|
|
finalizedBid = finalizedBsi.bid # For fallback `break` at start of loop
|
|
|
|
# Save best light client data for given period
|
|
var update {.noinit.}: LightClientUpdate
|
|
let attestedBid = dag.existingParent(signatureBid).valueOr:
|
|
return
|
|
dag.withUpdatedExistingState(tmpState[], attestedBid.atSlot) do:
|
|
let bdata = dag.getExistingForkedBlock(bid).valueOr:
|
|
return
|
|
withStateAndBlck(state, bdata):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
update.attested_header = blck.toBeaconBlockHeader
|
|
update.next_sync_committee = state.data.next_sync_committee
|
|
state.data.build_proof(
|
|
altair.NEXT_SYNC_COMMITTEE_INDEX,
|
|
update.next_sync_committee_branch)
|
|
if finalizedBid.slot == FAR_FUTURE_SLOT:
|
|
update.finality_branch.reset()
|
|
else:
|
|
state.data.build_proof(
|
|
altair.FINALIZED_ROOT_INDEX,
|
|
update.finality_branch)
|
|
else: raiseAssert "Unreachable"
|
|
do: return
|
|
if finalizedBid.slot == FAR_FUTURE_SLOT or finalizedBid.slot == GENESIS_SLOT:
|
|
update.finalized_header.reset()
|
|
else:
|
|
let bdata = dag.getExistingForkedBlock(finalizedBid).valueOr:
|
|
return
|
|
withBlck(bdata):
|
|
update.finalized_header = blck.toBeaconBlockHeader
|
|
let bdata = dag.getExistingForkedBlock(signatureBid).valueOr:
|
|
return
|
|
withBlck(bdata):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
update.sync_aggregate =
|
|
isomorphicCast[SyncAggregate](blck.message.body.sync_aggregate)
|
|
else: raiseAssert "Unreachable"
|
|
update.signature_slot = signatureBid.slot
|
|
dag.lightClientCache.best[period] = update
|
|
|
|
proc initLightClientCache*(dag: ChainDAGRef) =
|
|
## Initialize cached light client data
|
|
if dag.importLightClientData == ImportLightClientData.None:
|
|
return
|
|
dag.lightClientCache.importTailSlot = dag.tail.slot
|
|
if dag.importLightClientData == ImportLightClientData.OnlyNew:
|
|
dag.lightClientCache.importTailSlot = dag.head.slot
|
|
var earliestSlot = dag.computeEarliestLightClientSlot
|
|
if dag.head.slot < earliestSlot:
|
|
return
|
|
|
|
# Import light client data for finalized period through finalized head
|
|
let
|
|
finalizedSlot = dag.finalizedHead.slot
|
|
finalizedPeriod = finalizedSlot.sync_committee_period
|
|
dag.initLightClientBootstrapForPeriod(finalizedPeriod)
|
|
dag.initLightClientUpdateForPeriod(finalizedPeriod)
|
|
|
|
let lightClientStartTick = Moment.now()
|
|
debug "Initializing cached light client data"
|
|
|
|
template handleUnexpectedError(buggedBid: BlockId) =
|
|
# Light client data is expected to be available from `earliestSlot` onward.
|
|
# If there is an error, adjust `importTailSlot` to avoid failed lookups of
|
|
# cached light client data. For new blocks / states, the caches can always
|
|
# be updated incrementally, because those blocks / states are passed in
|
|
# directly. It is only historical blocks (or sync committees) that depend
|
|
# on a potentially corrupted database.
|
|
doAssert buggedBid.slot > dag.lightClientCache.importTailSlot
|
|
dag.lightClientCache.importTailSlot = buggedBid.slot + 1
|
|
earliestSlot = dag.computeEarliestLightClientSlot
|
|
|
|
# Build list of block to process.
|
|
# As it is slow to load states in descending order,
|
|
# build a reverse todo list to then process them in ascending order
|
|
let lowSlot = max(finalizedSlot, earliestSlot)
|
|
var
|
|
blocks = newSeqOfCap[BlockId](dag.head.slot - lowSlot + 1)
|
|
bid = dag.head.bid
|
|
while bid.slot > lowSlot:
|
|
blocks.add bid
|
|
bid = dag.existingParent(bid).valueOr:
|
|
handleUnexpectedError(bid)
|
|
break
|
|
if bid.slot == lowSlot:
|
|
blocks.add bid
|
|
|
|
# Process blocks (reuses `dag.headState`, but restores it to the current head)
|
|
var
|
|
tmpState = assignClone(dag.headState)
|
|
tmpCache, cache: StateCache
|
|
oldCheckpoint: Checkpoint
|
|
cpIndex = 0
|
|
for i in countdown(blocks.high, blocks.low):
|
|
bid = blocks[i]
|
|
if not dag.updateExistingState(
|
|
dag.headState, bid.atSlot, save = false, cache):
|
|
handleUnexpectedError(bid)
|
|
continue
|
|
withStateVars(dag.headState):
|
|
let bdata = dag.getExistingForkedBlock(bid).valueOr:
|
|
handleUnexpectedError(bid)
|
|
continue
|
|
withStateAndBlck(state, bdata):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
# Cache light client data (non-finalized blocks may refer to this)
|
|
dag.cacheLightClientData(state, blck)
|
|
|
|
# Create `LightClientUpdate` instances
|
|
if bid.slot != lowSlot:
|
|
dag.createLightClientUpdates(state, blck, parentBid = blocks[i + 1])
|
|
else: raiseAssert "Unreachable"
|
|
|
|
let lightClientEndTick = Moment.now()
|
|
debug "Initialized cached light client data",
|
|
initDur = lightClientEndTick - lightClientStartTick
|
|
|
|
# Import historic data
|
|
if dag.importLightClientData == ImportLightClientData.Full:
|
|
let earliestPeriod = earliestSlot.sync_committee_period
|
|
for period in earliestPeriod ..< finalizedPeriod:
|
|
dag.initLightClientBootstrapForPeriod(period)
|
|
dag.initLightClientUpdateForPeriod(period)
|
|
|
|
proc getLightClientBootstrap*(
|
|
dag: ChainDAGRef,
|
|
blockRoot: Eth2Digest): Opt[altair.LightClientBootstrap] =
|
|
if not dag.serveLightClientData:
|
|
return err()
|
|
|
|
let bdata = dag.getForkedBlock(blockRoot).valueOr:
|
|
debug "LC bootstrap unavailable: Block not found", blockRoot
|
|
return err()
|
|
|
|
withBlck(bdata):
|
|
let slot = blck.message.slot
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
let earliestSlot = dag.computeEarliestLightClientSlot
|
|
if slot < earliestSlot:
|
|
debug "LC bootstrap unavailable: Block too old", slot
|
|
return err()
|
|
if slot > dag.finalizedHead.blck.slot:
|
|
debug "LC bootstrap unavailable: Not finalized", blockRoot
|
|
return err()
|
|
var cachedBootstrap = dag.lightClientCache.bootstrap.getOrDefault(slot)
|
|
if cachedBootstrap.current_sync_committee_branch.isZeroMemory:
|
|
if dag.importLightClientData == ImportLightClientData.OnDemand:
|
|
let bsi = ? dag.getExistingBlockIdAtSlot(slot)
|
|
var tmpState = assignClone(dag.headState)
|
|
dag.withUpdatedExistingState(tmpState[], bsi) do:
|
|
withState(state):
|
|
when stateFork >= BeaconStateFork.Altair:
|
|
state.data.build_proof(
|
|
altair.CURRENT_SYNC_COMMITTEE_INDEX,
|
|
cachedBootstrap.current_sync_committee_branch)
|
|
else: raiseAssert "Unreachable"
|
|
do: return err()
|
|
dag.lightClientCache.bootstrap[slot] = cachedBootstrap
|
|
else:
|
|
debug "LC bootstrap unavailable: Data not cached", slot
|
|
return err()
|
|
|
|
let period = slot.sync_committee_period
|
|
var tmpState = assignClone(dag.headState)
|
|
var bootstrap {.noinit.}: altair.LightClientBootstrap
|
|
bootstrap.header =
|
|
blck.toBeaconBlockHeader
|
|
bootstrap.current_sync_committee =
|
|
? dag.existingCurrentSyncCommitteeForPeriod(tmpState[], period)
|
|
bootstrap.current_sync_committee_branch =
|
|
cachedBootstrap.current_sync_committee_branch
|
|
return ok bootstrap
|
|
else:
|
|
debug "LC bootstrap unavailable: Block before Altair", slot
|
|
return err()
|
|
|
|
proc getLightClientUpdateForPeriod*(
|
|
dag: ChainDAGRef,
|
|
period: SyncCommitteePeriod): Option[altair.LightClientUpdate] =
|
|
if not dag.serveLightClientData:
|
|
return
|
|
|
|
if dag.importLightClientData == ImportLightClientData.OnDemand:
|
|
dag.initLightClientUpdateForPeriod(period)
|
|
result = some(dag.lightClientCache.best.getOrDefault(period))
|
|
let numParticipants = countOnes(result.get.sync_aggregate.sync_committee_bits)
|
|
if numParticipants < MIN_SYNC_COMMITTEE_PARTICIPANTS:
|
|
result.reset()
|
|
|
|
proc getLightClientFinalityUpdate*(
|
|
dag: ChainDAGRef): Option[altair.LightClientFinalityUpdate] =
|
|
if not dag.serveLightClientData:
|
|
return
|
|
|
|
result = some(dag.lightClientCache.latest)
|
|
let numParticipants = countOnes(result.get.sync_aggregate.sync_committee_bits)
|
|
if numParticipants < MIN_SYNC_COMMITTEE_PARTICIPANTS:
|
|
result.reset()
|
|
|
|
proc getLightClientOptimisticUpdate*(
|
|
dag: ChainDAGRef): Option[altair.LightClientOptimisticUpdate] =
|
|
if not dag.serveLightClientData:
|
|
return
|
|
|
|
result = some(dag.lightClientCache.latest.toOptimistic)
|
|
let numParticipants = countOnes(result.get.sync_aggregate.sync_committee_bits)
|
|
if numParticipants < MIN_SYNC_COMMITTEE_PARTICIPANTS:
|
|
result.reset()
|