93 lines
3.8 KiB
Nim
93 lines
3.8 KiB
Nim
# beacon_chain
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# Copyright (c) 2018 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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import
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# Standard library
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strformat, tables,
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# Specs
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../../beacon_chain/spec/[datatypes, state_transition_epoch, validator, helpers],
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# Test helpers
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../helpers/digest_helpers
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# Justification and finalization utils
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# ---------------------------------------------------------------
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proc addMockAttestations*(
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state: var BeaconState, epoch: Epoch,
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source, target: Checkpoint,
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sufficient_support = false
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) =
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# We must be at the end of the epoch
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doAssert (state.slot + 1).isEpoch
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# Alias the attestations container
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var attestations: ptr seq[PendingAttestation]
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if state.get_current_epoch() == epoch:
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attestations = state.current_epoch_attestations.asSeq.addr
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elif state.get_previous_epoch() == epoch:
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attestations = state.previous_epoch_attestations.asSeq.addr
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else:
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raise newException(ValueError, &"Cannot include attestations from epoch {state.get_current_epoch()} in epoch {epoch}")
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# TODO: Working with an unsigned Gwei balance is a recipe for underflows to happen
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var cache = StateCache()
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var remaining_balance = state.get_total_active_balance(cache).int64 * 2 div 3
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let
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start_slot = compute_start_slot_at_epoch(epoch)
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committees_per_slot = get_committee_count_per_slot(state, epoch, cache)
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# for-loop of distinct type is broken: https://github.com/nim-lang/Nim/issues/12074
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for slot in start_slot.uint64 ..< start_slot.uint64 + SLOTS_PER_EPOCH:
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for index in 0'u64 ..< committees_per_slot:
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let committee = get_beacon_committee(
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state, slot.Slot, index.CommitteeIndex, cache)
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# Create a bitfield filled with the given count per attestation,
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# exactly on the right-most part of the committee field.
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var aggregation_bits = init(CommitteeValidatorsBits, committee.len)
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for v in 0 ..< committee.len * 2 div 3 + 1:
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if remaining_balance > 0:
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# Beware of the underflows, use int
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remaining_balance -= state.validators[v].effective_balance.int64
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aggregation_bits[v] = true
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else:
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break
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# Remove just one attester to make the marginal support insufficient
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if not sufficient_support:
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# Find the first attester if any
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let idx = aggregation_bits.find(true)
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if idx != -1:
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aggregation_bits[idx] = false
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attestations[].add PendingAttestation(
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aggregation_bits: aggregation_bits,
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data: AttestationData(
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slot: slot.Slot,
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index: index,
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beacon_block_root: [byte 0xFF] * 32, # Irrelevant for testing
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source: source,
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target: target,
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),
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inclusion_delay: 1
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)
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proc getCheckpoints*(epoch: Epoch): tuple[c1, c2, c3, c4, c5: Checkpoint] =
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if epoch >= 1: result.c1 = Checkpoint(epoch: epoch - 1, root: [byte 0xAA] * 32)
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if epoch >= 2: result.c2 = Checkpoint(epoch: epoch - 2, root: [byte 0xBB] * 32)
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if epoch >= 3: result.c3 = Checkpoint(epoch: epoch - 3, root: [byte 0xCC] * 32)
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if epoch >= 4: result.c4 = Checkpoint(epoch: epoch - 4, root: [byte 0xDD] * 32)
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if epoch >= 5: result.c5 = Checkpoint(epoch: epoch - 5, root: [byte 0xEE] * 32)
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proc putCheckpointsInBlockRoots*(
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state: var BeaconState,
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checkpoints: openArray[Checkpoint]) =
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for c in checkpoints:
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let idx = c.epoch.compute_start_slot_at_epoch() mod SLOTS_PER_HISTORICAL_ROOT
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state.block_roots[idx] = c.root
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