nimbus-eth2/beacon_chain/spec/validator.nim

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2019-02-25 14:48:36 +00:00
# Copyright (c) 2018-2019 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
# Helpers and functions pertaining to managing the validator set
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import
options, nimcrypto, sequtils, math, tables,
./datatypes, ./digest, ./helpers
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# TODO: Proceed to renaming and signature changes
initial 0.9.0 spec sync (#509) * rename compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * remove some unnecessary imports; remove some crosslink-related code and tests; complete renaming of compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * rm more transfer-related code and tests; rm more unnecessary strutils imports * rm remaining unused imports * remove useless get_empty_per_epoch_cache(...)/compute_start_slot_of_epoch(...) calls * rename compute_start_slot_of_epoch(...) to compute_start_slot_at_epoch(...) * rename ACTIVATION_EXIT_DELAY to MAX_SEED_LOOKAHEAD * update domain types to 0.9.0 * mark AttesterSlashing, IndexedAttestation, AttestationDataAndCustodyBit, DepositData, BeaconBlockHeader, Fork, integer_squareroot(...), and process_voluntary_exit(...) as 0.9.0 * mark increase_balance(...), decrease_balance(...), get_block_root(...), CheckPoint, Deposit, PendingAttestation, HistoricalBatch, is_active_validator(...), and is_slashable_attestation_data(...) as 0.9.0 * mark compute_activation_exit_epoch(...), bls_verify(...), Validator, get_active_validator_indices(...), get_current_epoch(...), get_total_active_balance(...), and get_previous_epoch(...) as 0.9.0 * mark get_block_root_at_slot(...), ProposerSlashing, get_domain(...), VoluntaryExit, mainnet preset Gwei values, minimal preset max operations, process_block_header(...), and is_slashable_validator(...) as 0.9.0 * mark makeWithdrawalCredentials(...), get_validator_churn_limit(...), get_total_balance(...), is_valid_indexed_attestation(...), bls_aggregate_pubkeys(...), initial genesis value/constants, Attestation, get_randao_mix(...), mainnet preset max operations per block constants, minimal preset Gwei values and time parameters, process_eth1_data(...), get_shuffled_seq(...), compute_committee(...), and process_slots(...) as 0.9.0; partially update get_indexed_attestation(...) to 0.9.0 by removing crosslink refs and associated tests * mark initiate_validator_exit(...), process_registry_updates(...), BeaconBlock, Eth1Data, compute_domain(...), process_randao(...), process_attester_slashing(...), get_base_reward(...), and process_slot(...) as 0.9.0
2019-10-30 19:41:19 +00:00
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.0/specs/core/0_beacon-chain.md#compute_shuffled_index
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.0/specs/core/0_beacon-chain.md#compute_committee
func get_shuffled_seq*(seed: Eth2Digest,
list_size: uint64,
): seq[ValidatorIndex] =
## Via https://github.com/protolambda/eth2-shuffle/blob/master/shuffle.go
## Shuffles ``validators`` into crosslink committees seeded by ``seed`` and
## ``slot``.
## Returns a list of ``SLOTS_PER_EPOCH * committees_per_slot`` committees
## where each committee is itself a list of validator indices.
##
## Invert the inner/outer loops from the spec, essentially. Most useful
## hash result re-use occurs within a round.
# Empty size -> empty list.
if list_size == 0:
return
var
# Share these buffers.
# TODO: Redo to follow spec.
# We can have an "Impl" private version that takes buffer as parameters
# so that we avoid alloc on repeated calls from compute_committee
pivot_buffer: array[(32+1), byte]
source_buffer: array[(32+1+4), byte]
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shuffled_active_validator_indices = mapIt(
0 ..< list_size.int, it.ValidatorIndex)
sources = repeat(Eth2Digest(), (list_size div 256) + 1)
## The pivot's a function of seed and round only.
## This doesn't change across rounds.
pivot_buffer[0..31] = seed.data
source_buffer[0..31] = seed.data
for round in 0 ..< SHUFFLE_ROUND_COUNT:
let round_bytes1 = int_to_bytes1(round)[0]
pivot_buffer[32] = round_bytes1
source_buffer[32] = round_bytes1
# Only one pivot per round.
let pivot = bytes_to_int(eth2hash(pivot_buffer).data.toOpenArray(0, 7)) mod list_size
## Only need to run, per round, position div 256 hashes, so precalculate
## them. This consumes memory, but for low-memory devices, it's possible
## to mitigate by some light LRU caching and similar.
for reduced_position in 0 ..< sources.len:
source_buffer[33..36] = int_to_bytes4(reduced_position.uint64)
sources[reduced_position] = eth2hash(source_buffer)
## Iterate over all the indices. This was in get_permuted_index, but large
## efficiency gains exist in caching and re-using data.
for index in 0 ..< list_size.int:
let
cur_idx_permuted = shuffled_active_validator_indices[index]
flip = ((list_size + pivot) - cur_idx_permuted.uint64) mod list_size
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position = max(cur_idx_permuted.int, flip.int)
let
source = sources[position div 256].data
byte_value = source[(position mod 256) div 8]
bit = (byte_value shr (position mod 8)) mod 2
if bit != 0:
shuffled_active_validator_indices[index] = flip.ValidatorIndex
result = shuffled_active_validator_indices
initial 0.9.0 spec sync (#509) * rename compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * remove some unnecessary imports; remove some crosslink-related code and tests; complete renaming of compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * rm more transfer-related code and tests; rm more unnecessary strutils imports * rm remaining unused imports * remove useless get_empty_per_epoch_cache(...)/compute_start_slot_of_epoch(...) calls * rename compute_start_slot_of_epoch(...) to compute_start_slot_at_epoch(...) * rename ACTIVATION_EXIT_DELAY to MAX_SEED_LOOKAHEAD * update domain types to 0.9.0 * mark AttesterSlashing, IndexedAttestation, AttestationDataAndCustodyBit, DepositData, BeaconBlockHeader, Fork, integer_squareroot(...), and process_voluntary_exit(...) as 0.9.0 * mark increase_balance(...), decrease_balance(...), get_block_root(...), CheckPoint, Deposit, PendingAttestation, HistoricalBatch, is_active_validator(...), and is_slashable_attestation_data(...) as 0.9.0 * mark compute_activation_exit_epoch(...), bls_verify(...), Validator, get_active_validator_indices(...), get_current_epoch(...), get_total_active_balance(...), and get_previous_epoch(...) as 0.9.0 * mark get_block_root_at_slot(...), ProposerSlashing, get_domain(...), VoluntaryExit, mainnet preset Gwei values, minimal preset max operations, process_block_header(...), and is_slashable_validator(...) as 0.9.0 * mark makeWithdrawalCredentials(...), get_validator_churn_limit(...), get_total_balance(...), is_valid_indexed_attestation(...), bls_aggregate_pubkeys(...), initial genesis value/constants, Attestation, get_randao_mix(...), mainnet preset max operations per block constants, minimal preset Gwei values and time parameters, process_eth1_data(...), get_shuffled_seq(...), compute_committee(...), and process_slots(...) as 0.9.0; partially update get_indexed_attestation(...) to 0.9.0 by removing crosslink refs and associated tests * mark initiate_validator_exit(...), process_registry_updates(...), BeaconBlock, Eth1Data, compute_domain(...), process_randao(...), process_attester_slashing(...), get_base_reward(...), and process_slot(...) as 0.9.0
2019-10-30 19:41:19 +00:00
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.0/specs/core/0_beacon-chain.md#get_previous_epoch
func get_previous_epoch*(state: BeaconState): Epoch =
# Return the previous epoch (unless the current epoch is ``GENESIS_EPOCH``).
let current_epoch = get_current_epoch(state)
if current_epoch == GENESIS_EPOCH:
current_epoch
else:
More 0.8.0 updates (#311) * replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0 * update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0 * mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0 * rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...) * convert remaining references to finalized_epoch to finalized_checkpoint.epoch * update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0 * rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0 * update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0 * replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
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current_epoch - 1
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/core/0_beacon-chain.md#get_shard_delta
func get_shard_delta*(state: BeaconState, epoch: Epoch): uint64 =
## Return the number of shards to increment ``state.start_shard``
## during ``epoch``.
min(get_committee_count(state, epoch),
(SHARD_COUNT - SHARD_COUNT div SLOTS_PER_EPOCH).uint64)
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/core/0_beacon-chain.md#get_start_shard
func get_start_shard*(state: BeaconState, epoch: Epoch): Shard =
# Return the start shard of the 0th committee at ``epoch``.
doAssert epoch <= get_current_epoch(state) + 1
var
check_epoch = get_current_epoch(state) + 1
shard =
(state.start_shard +
get_shard_delta(state, get_current_epoch(state))) mod SHARD_COUNT
while check_epoch > epoch:
check_epoch -= 1.Epoch
shard = (shard + SHARD_COUNT - get_shard_delta(state, check_epoch)) mod
SHARD_COUNT
return shard
# TODO remove when shim layer isn't needed
func get_slot_and_index*(state: BeaconState, epoch: Epoch, shard: Shard): auto =
# This is simply the index get_crosslink_committee(...) computes for
# compute_committee(...)
let gcc_index = (shard + SHARD_COUNT - get_start_shard(state, epoch)) mod SHARD_COUNT
# Want (slot % SLOTS_PER_EPOCH) * committees_per_slot + index to result in
# same index, where
# committees_per_slot = get_committee_count_at_slot(state, slot)
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.0/specs/core/0_beacon-chain.md#get_beacon_committee
let committees_per_slot = get_committee_count_at_slot(state, compute_start_slot_at_epoch(epoch))
# get_beacon_committee(...) uses a straightforward linear mapping, row-centric
# minimize the `index` offset (s.t. >= 0) and maximize `slot`.
let
slot = gcc_index div committees_per_slot
index = gcc_index mod committees_per_slot
# TODO it might be bad if slot >= SLOTS_PER_EPOCH in this construction,
# but not necessarily
(compute_start_slot_at_epoch(epoch) + slot, index)
initial 0.9.0 spec sync (#509) * rename compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * remove some unnecessary imports; remove some crosslink-related code and tests; complete renaming of compute_epoch_of_slot(...) to compute_epoch_at_slot(...) * rm more transfer-related code and tests; rm more unnecessary strutils imports * rm remaining unused imports * remove useless get_empty_per_epoch_cache(...)/compute_start_slot_of_epoch(...) calls * rename compute_start_slot_of_epoch(...) to compute_start_slot_at_epoch(...) * rename ACTIVATION_EXIT_DELAY to MAX_SEED_LOOKAHEAD * update domain types to 0.9.0 * mark AttesterSlashing, IndexedAttestation, AttestationDataAndCustodyBit, DepositData, BeaconBlockHeader, Fork, integer_squareroot(...), and process_voluntary_exit(...) as 0.9.0 * mark increase_balance(...), decrease_balance(...), get_block_root(...), CheckPoint, Deposit, PendingAttestation, HistoricalBatch, is_active_validator(...), and is_slashable_attestation_data(...) as 0.9.0 * mark compute_activation_exit_epoch(...), bls_verify(...), Validator, get_active_validator_indices(...), get_current_epoch(...), get_total_active_balance(...), and get_previous_epoch(...) as 0.9.0 * mark get_block_root_at_slot(...), ProposerSlashing, get_domain(...), VoluntaryExit, mainnet preset Gwei values, minimal preset max operations, process_block_header(...), and is_slashable_validator(...) as 0.9.0 * mark makeWithdrawalCredentials(...), get_validator_churn_limit(...), get_total_balance(...), is_valid_indexed_attestation(...), bls_aggregate_pubkeys(...), initial genesis value/constants, Attestation, get_randao_mix(...), mainnet preset max operations per block constants, minimal preset Gwei values and time parameters, process_eth1_data(...), get_shuffled_seq(...), compute_committee(...), and process_slots(...) as 0.9.0; partially update get_indexed_attestation(...) to 0.9.0 by removing crosslink refs and associated tests * mark initiate_validator_exit(...), process_registry_updates(...), BeaconBlock, Eth1Data, compute_domain(...), process_randao(...), process_attester_slashing(...), get_base_reward(...), and process_slot(...) as 0.9.0
2019-10-30 19:41:19 +00:00
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.0/specs/core/0_beacon-chain.md#compute_committee
func compute_committee(indices: seq[ValidatorIndex], seed: Eth2Digest,
index: uint64, count: uint64, stateCache: var StateCache): seq[ValidatorIndex] =
## Return the committee corresponding to ``indices``, ``seed``, ``index``,
## and committee ``count``.
let
start = (len(indices).uint64 * index) div count
endIdx = (len(indices).uint64 * (index + 1)) div count
key = (indices.len, seed)
if key notin stateCache.crosslink_committee_cache:
stateCache.crosslink_committee_cache[key] =
get_shuffled_seq(seed, len(indices).uint64)
# These assertions from compute_shuffled_index(...)
let index_count = indices.len().uint64
doAssert endIdx <= index_count
doAssert index_count <= 2'u64^40
# In spec, this calls get_shuffled_index() every time, but that's wasteful
mapIt(
start.int .. (endIdx.int-1),
indices[stateCache.crosslink_committee_cache[key][it]])
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/core/0_beacon-chain.md#get_beacon_committee
func get_beacon_committee*(state: BeaconState, slot: Slot, index: uint64, cache: var StateCache, gcc_index: uint64 = 100): seq[ValidatorIndex] =
# Return the beacon committee at ``slot`` for ``index``.
let
epoch = compute_epoch_at_slot(slot)
committees_per_slot = get_committee_count_at_slot(state, slot)
let gbc_index = (slot mod SLOTS_PER_EPOCH) * committees_per_slot + index
doAssert gcc_index == 100 or gbc_index == gcc_index
if epoch notin cache.committee_count_cache:
cache.committee_count_cache[epoch] = get_committee_count(state, epoch)
# TODO profiling & make sure caches populated
compute_committee(
cache.active_validator_indices_cache[epoch],
# TODO switch to 0.9 seed calculation
#get_seed(state, epoch, DOMAIN_BEACON_ATTESTER),
get_seed(state, epoch),
(slot mod SLOTS_PER_EPOCH) * committees_per_slot + index,
# TODO switch to 0.9's
# committees_per_slot * SLOTS_PER_EPOCH,
cache.committee_count_cache[epoch],
cache
)
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/core/0_beacon-chain.md#get_crosslink_committee
func get_crosslink_committee*(state: BeaconState, epoch: Epoch, shard: Shard,
stateCache: var StateCache): seq[ValidatorIndex] =
doAssert shard >= 0'u64
# This seems to be required, basically, to be true? But I'm not entirely sure
#doAssert shard >= get_start_shard(state, epoch)
## This is a somewhat more fragile, but high-ROI, caching setup --
## get_active_validator_indices() is slow to run in a loop and only
## changes once per epoch.
if epoch notin stateCache.active_validator_indices_cache:
stateCache.active_validator_indices_cache[epoch] =
get_active_validator_indices(state, epoch)
if epoch notin stateCache.start_shard_cache:
stateCache.start_shard_cache[epoch] = get_start_shard(state, epoch)
if epoch notin stateCache.committee_count_cache:
stateCache.committee_count_cache[epoch] = get_committee_count(state, epoch)
let gcc_index = (shard + SHARD_COUNT - stateCache.start_shard_cache[epoch]) mod SHARD_COUNT
let old = compute_committee(
stateCache.active_validator_indices_cache[epoch],
get_seed(state, epoch),
(shard + SHARD_COUNT - stateCache.start_shard_cache[epoch]) mod
SHARD_COUNT,
stateCache.committee_count_cache[epoch],
stateCache
)
let
(gbc_slot, gbc_index) = get_slot_and_index(state, epoch, shard)
new = get_beacon_committee(
state, gbc_slot, gbc_index, stateCache, gcc_index)
doAssert old == new
result = new
# Not from spec
func get_empty_per_epoch_cache*(): StateCache =
result.crosslink_committee_cache =
initTable[tuple[a: int, b: Eth2Digest], seq[ValidatorIndex]]()
result.active_validator_indices_cache =
initTable[Epoch, seq[ValidatorIndex]]()
result.start_shard_cache = initTable[Epoch, Shard]()
result.committee_count_cache = initTable[Epoch, uint64]()
0.6.2 updates (#275) * update process_justification_and_finalization to 0.6.2; mark AttesterSlashing as 0.6.2 * replace get_effective_balance(...) with state.validator_registry[idx].effective_balance; rm get_effective_balance, process_ejections, should_update_validator_registry, update_validator_registry, and update_registry_and_shuffling_data; update get_total_balance to 0.6.2; implement process_registry_updates * rm exit_validator; implement is_slashable_attestation_data; partly update processAttesterSlashings * mark HistoricalBatch and Eth1Data as 0.6.2; implement get_shard_delta(...); replace 0.5 finish_epoch_update with 0.6 process_final_updates * mark increase_balance, decrease_balance, get_delayed_activation_exit_epoch, bls_aggregate_pubkeys, bls_verify_multiple, Attestation, Transfer, slot_to_epoch, Crosslink, get_current_epoch, int_to_bytes*, various constants, processEth1Data, processTransfers, and verifyStateRoot as 0.6.2; rm is_double_vote and is_surround_vote * mark get_bitfield_bit, verify_bitfield, ProposerSlashing, DepositData, VoluntaryExit, PendingAttestation, Fork, integer_squareroot, get_epoch_start_slot, is_active_validator, generate_seed, some constants to 0.6.2; rename MIN_PENALTY_QUOTIENT to MIN_SLASHING_PENALTY_QUOTIENT * rm get_previous_total_balance, get_current_epoch_boundary_attestations, get_previous_epoch_boundary_attestations, and get_previous_epoch_matching_head_attestations * update BeaconState to 0.6.2; simplify legacy get_crosslink_committees_at_slot infrastructure a bit by noting that registry_change is always false; reimplment 0.5 get_crosslink_committees_at_slot in terms of 0.6 get_crosslink_committee * mark process_deposit(...), get_block_root_at_slot(...), get_block_root(...), Deposit, BeaconBlockHeader, BeaconBlockBody, hash(...), get_active_index_root(...), various constants, get_shard_delta(...), get_epoch_start_shard(...), get_crosslink_committee(...), processRandao(...), processVoluntaryExits(...), cacheState(...) as 0.6.2 * rm removed-since-0.5 split(...), is_power_of_2(...), get_shuffling(...); rm 0.5 versions of get_active_validator_indices and get_epoch_committee_count; add a few tests for integer_squareroot * mark bytes_to_int(...) and advanceState(...) as 0.6.2 * rm 0.5 get_attesting_indices; update get_attesting_balance to 0.6.2 * another tiny commit to poke AppVeyor to maybe not timeout at connecting to GitHub partway through CI: mark get_churn_limit(...), initiate_validator_exit(...), and Validator as 0.6.2 * mark get_attestation_slot(...), AttestationDataAndCustodyBit, and BeaconBlock as 0.6.2
2019-06-03 10:31:04 +00:00
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/core/0_beacon-chain.md#get_beacon_proposer_index
func get_beacon_proposer_index*(state: BeaconState, stateCache: var StateCache):
ValidatorIndex =
More 0.8.0 updates (#311) * replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0 * update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0 * mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0 * rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...) * convert remaining references to finalized_epoch to finalized_checkpoint.epoch * update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0 * rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0 * update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0 * replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
2019-07-05 08:30:05 +00:00
# Return the beacon proposer index at the current slot.
const
MAX_RANDOM_BYTE = 255
let
epoch = get_current_epoch(state)
committees_per_slot =
get_committee_count(state, epoch) div SLOTS_PER_EPOCH
offset = committees_per_slot * (state.slot mod SLOTS_PER_EPOCH)
shard = (get_start_shard(state, epoch) + offset) mod SHARD_COUNT
first_committee = get_crosslink_committee(state, epoch, shard, stateCache)
seed = get_seed(state, epoch)
# This mainly fails when there are no active validators for some reason
doAssert first_committee.len > 0
var
i = 0
buffer: array[(32+8), byte]
buffer[0..31] = seed.data
while true:
More 0.8.0 updates (#311) * replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0 * update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0 * mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0 * rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...) * convert remaining references to finalized_epoch to finalized_checkpoint.epoch * update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0 * rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0 * update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0 * replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
2019-07-05 08:30:05 +00:00
# TODO update to new int_to_bytes interface
buffer[32..39] = int_to_bytes8(i.uint64 div 32)
let
candidate_index = first_committee[((epoch + i.uint64) mod
len(first_committee).uint64).int]
random_byte = (eth2hash(buffer).data)[i mod 32]
effective_balance =
state.validators[candidate_index].effective_balance
if effective_balance * MAX_RANDOM_BYTE >=
MAX_EFFECTIVE_BALANCE * random_byte:
return candidate_index
i += 1