Tidy per epoch processing

- Add comments to ValidatorStatuses
- Add some checks to guard against a bad statuses list
- Remove unused attester_sets.rs file.
This commit is contained in:
Paul Hauner 2019-03-14 16:00:22 +11:00
parent 10aee6214c
commit 1c1c15a122
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GPG Key ID: D362883A9218FCC6
4 changed files with 87 additions and 143 deletions

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@ -7,7 +7,6 @@ use types::{validator_registry::get_active_validator_indices, *};
use validator_statuses::{TotalBalances, ValidatorStatuses};
use winning_root::{winning_root, WinningRoot};
pub mod attester_sets;
pub mod errors;
pub mod inclusion_distance;
pub mod tests;
@ -271,12 +270,18 @@ pub fn process_rewards_and_penalities(
let base_reward_quotient =
total_balances.previous_epoch.integer_sqrt() / spec.base_reward_quotient;
// Guard against a divide-by-zero during the validator balance update.
if base_reward_quotient == 0 {
return Err(Error::BaseRewardQuotientIsZero);
}
// Guard against a divide-by-zero during the validator balance update.
if total_balances.previous_epoch == 0 {
return Err(Error::PreviousTotalBalanceIsZero);
}
// Guard against an out-of-bounds during the validator balance update.
if statuses.statuses.len() != state.validator_balances.len() {
return Err(Error::ValidatorStatusesInconsistent);
}
// Justification and finalization
@ -288,7 +293,7 @@ pub fn process_rewards_and_penalities(
.enumerate()
.map(|(index, &balance)| {
let mut balance = balance;
let status = &statuses.get(index);
let status = &statuses.statuses[index];
let base_reward = state.base_reward(index, base_reward_quotient, spec);
if epochs_since_finality <= 4 {
@ -367,8 +372,13 @@ pub fn process_rewards_and_penalities(
// Attestation inclusion
// Guard against an out-of-bounds during the attester inclusion balance update.
if statuses.statuses.len() != state.validator_registry.len() {
return Err(Error::ValidatorStatusesInconsistent);
}
for (index, _validator) in state.validator_registry.iter().enumerate() {
let status = &statuses.get(index);
let status = &statuses.statuses[index];
if status.is_previous_epoch_attester {
let proposer_index = status.inclusion_info.proposer_index;

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@ -1,133 +0,0 @@
use fnv::FnvHashSet;
use types::*;
/// A set of validator indices, along with the total balance of all those attesters.
#[derive(Default)]
pub struct Attesters {
/// A set of validator indices.
pub indices: FnvHashSet<usize>,
/// The total balance of all validators in `self.indices`.
pub balance: u64,
}
impl Attesters {
/// Add the given indices to the set, incrementing the sets balance by the provided balance.
fn add(&mut self, additional_indices: &[usize], additional_balance: u64) {
self.indices.reserve(additional_indices.len());
for i in additional_indices {
self.indices.insert(*i);
}
self.balance = self.balance.saturating_add(additional_balance);
}
}
/// A collection of `Attester` objects, representing set of attesters that are rewarded/penalized
/// during an epoch transition.
pub struct AttesterSets {
/// All validators who attested during the state's current epoch.
pub current_epoch: Attesters,
/// All validators who attested that the beacon block root of the first slot of the state's
/// current epoch is the same as the one stored in this state.
///
/// In short validators who agreed with the state about the first slot of the current epoch.
pub current_epoch_boundary: Attesters,
/// All validators who attested during the state's previous epoch.
pub previous_epoch: Attesters,
/// All validators who attested that the beacon block root of the first slot of the state's
/// previous epoch is the same as the one stored in this state.
///
/// In short, validators who agreed with the state about the first slot of the previous epoch.
pub previous_epoch_boundary: Attesters,
/// All validators who attested that the beacon block root at the pending attestation's slot is
/// the same as the one stored in this state.
///
/// In short, validators who agreed with the state about the current beacon block root when
/// they attested.
pub previous_epoch_head: Attesters,
}
impl AttesterSets {
/// Loop through all attestations in the state and instantiate a complete `AttesterSets` struct.
///
/// Spec v0.4.0
pub fn new(state: &BeaconState, spec: &ChainSpec) -> Result<Self, BeaconStateError> {
let mut current_epoch = Attesters::default();
let mut current_epoch_boundary = Attesters::default();
let mut previous_epoch = Attesters::default();
let mut previous_epoch_boundary = Attesters::default();
let mut previous_epoch_head = Attesters::default();
for a in &state.latest_attestations {
let attesting_indices =
state.get_attestation_participants(&a.data, &a.aggregation_bitfield, spec)?;
let attesting_balance = state.get_total_balance(&attesting_indices, spec);
if is_from_epoch(a, state.current_epoch(spec), spec) {
current_epoch.add(&attesting_indices, attesting_balance);
if has_common_epoch_boundary_root(a, state, state.current_epoch(spec), spec)? {
current_epoch_boundary.add(&attesting_indices, attesting_balance);
}
} else if is_from_epoch(a, state.previous_epoch(spec), spec) {
previous_epoch.add(&attesting_indices, attesting_balance);
if has_common_epoch_boundary_root(a, state, state.previous_epoch(spec), spec)? {
previous_epoch_boundary.add(&attesting_indices, attesting_balance);
}
if has_common_beacon_block_root(a, state, spec)? {
previous_epoch_head.add(&attesting_indices, attesting_balance);
}
}
}
Ok(Self {
current_epoch,
current_epoch_boundary,
previous_epoch,
previous_epoch_boundary,
previous_epoch_head,
})
}
}
/// Returns `true` if some `PendingAttestation` is from the supplied `epoch`.
///
/// Spec v0.4.0
fn is_from_epoch(a: &PendingAttestation, epoch: Epoch, spec: &ChainSpec) -> bool {
a.data.slot.epoch(spec.slots_per_epoch) == epoch
}
/// Returns `true` if a `PendingAttestation` and `BeaconState` share the same beacon block hash for
/// the first slot of the given epoch.
///
/// Spec v0.4.0
fn has_common_epoch_boundary_root(
a: &PendingAttestation,
state: &BeaconState,
epoch: Epoch,
spec: &ChainSpec,
) -> Result<bool, BeaconStateError> {
let slot = epoch.start_slot(spec.slots_per_epoch);
let state_boundary_root = *state
.get_block_root(slot, spec)
.ok_or_else(|| BeaconStateError::InsufficientBlockRoots)?;
Ok(a.data.epoch_boundary_root == state_boundary_root)
}
/// Returns `true` if a `PendingAttestation` and `BeaconState` share the same beacon block hash for
/// the current slot of the `PendingAttestation`.
///
/// Spec v0.4.0
fn has_common_beacon_block_root(
a: &PendingAttestation,
state: &BeaconState,
spec: &ChainSpec,
) -> Result<bool, BeaconStateError> {
let state_block_root = *state
.get_block_root(a.data.slot, spec)
.ok_or_else(|| BeaconStateError::InsufficientBlockRoots)?;
Ok(a.data.beacon_block_root == state_block_root)
}

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@ -8,6 +8,7 @@ pub enum EpochProcessingError {
NoRandaoSeed,
PreviousTotalBalanceIsZero,
InclusionDistanceZero,
ValidatorStatusesInconsistent,
/// Unable to get the inclusion distance for a validator that should have an inclusion
/// distance. This indicates an internal inconsistency.
///

View File

@ -1,26 +1,40 @@
use super::WinningRootHashSet;
use types::*;
/// Sets the boolean `var` on `self` to be true if it is true on `other`. Otherwise leaves `self`
/// as is.
macro_rules! set_self_if_other_is_true {
($self_: ident, $other: ident, $var: ident) => {
$self_.$var = $other.$var & !$self_.$var;
if $other.$var {
$self_.$var = true;
}
};
}
/// The information required to reward some validator for their participation in a "winning"
/// crosslink root.
#[derive(Default, Clone)]
pub struct WinningRootInfo {
/// The total balance of the crosslink committee.
pub total_committee_balance: u64,
/// The total balance of the crosslink committee that attested for the "winning" root.
pub total_attesting_balance: u64,
}
/// The information required to reward a block producer for including an attestation in a block.
#[derive(Clone)]
pub struct InclusionInfo {
/// The earliest slot a validator had an attestation included in the previous epoch.
pub slot: Slot,
/// The distance between the attestation slot and the slot that attestation was included in a
/// block.
pub distance: Slot,
/// The index of the proposer at the slot where the attestation was included.
pub proposer_index: usize,
}
impl Default for InclusionInfo {
/// Defaults to `slot` and `distance` at their maximum values and `proposer_index` at zero.
fn default() -> Self {
Self {
slot: Slot::max_value(),
@ -31,6 +45,8 @@ impl Default for InclusionInfo {
}
impl InclusionInfo {
/// Tests if some `other` `InclusionInfo` has a lower inclusion slot than `self`. If so,
/// replaces `self` with `other`.
pub fn update(&mut self, other: &Self) {
if other.slot < self.slot {
self.slot = other.slot;
@ -40,23 +56,43 @@ impl InclusionInfo {
}
}
/// Information required to reward some validator during the current and previous epoch.
#[derive(Default, Clone)]
pub struct AttesterStatus {
/// True if the validator was active in the state's _current_ epoch.
pub is_active_in_current_epoch: bool,
/// True if the validator was active in the state's _previous_ epoch.
pub is_active_in_previous_epoch: bool,
/// True if the validator had an attestation included in the _current_ epoch.
pub is_current_epoch_attester: bool,
/// True if the validator's beacon block root attestation for the first slot of the _current_
/// epoch matches the block root known to the state.
pub is_current_epoch_boundary_attester: bool,
/// True if the validator had an attestation included in the _previous_ epoch.
pub is_previous_epoch_attester: bool,
/// True if the validator's beacon block root attestation for the first slot of the _previous_
/// epoch matches the block root known to the state.
pub is_previous_epoch_boundary_attester: bool,
/// True if the validator's beacon block root attestation in the _previous_ epoch at the
/// attestation's slot (`attestation_data.slot`) matches the block root known to the state.
pub is_previous_epoch_head_attester: bool,
/// Information used to reward the block producer of this validators earliest-included
/// attestation.
pub inclusion_info: InclusionInfo,
/// Information used to reward/penalize the validator if they voted in the super-majority for
/// some shard block.
pub winning_root_info: Option<WinningRootInfo>,
}
impl AttesterStatus {
/// Note: does not update the winning root info.
/// Accepts some `other` `AttesterStatus` and updates `self` if required.
///
/// Will never set one of the `bool` fields to `false`, it will only set it to `true` if other
/// contains a `true` field.
///
/// Note: does not update the winning root info, this is done manually.
pub fn update(&mut self, other: &Self) {
// Update all the bool fields, only updating `self` if `other` is true (never setting
// `self` to false).
@ -72,24 +108,46 @@ impl AttesterStatus {
}
}
/// The total effective balances for different sets of validators during the previous and current
/// epochs.
#[derive(Default, Clone)]
pub struct TotalBalances {
/// The total effective balance of all active validators during the _current_ epoch.
pub current_epoch: u64,
/// The total effective balance of all active validators during the _previous_ epoch.
pub previous_epoch: u64,
/// The total effective balance of all validators who attested during the _current_ epoch.
pub current_epoch_attesters: u64,
/// The total effective balance of all validators who attested during the _current_ epoch and
/// agreed with the state about the beacon block at the first slot of the _current_ epoch.
pub current_epoch_boundary_attesters: u64,
/// The total effective balance of all validators who attested during the _previous_ epoch.
pub previous_epoch_attesters: u64,
/// The total effective balance of all validators who attested during the _previous_ epoch and
/// agreed with the state about the beacon block at the first slot of the _previous_ epoch.
pub previous_epoch_boundary_attesters: u64,
/// The total effective balance of all validators who attested during the _previous_ epoch and
/// agreed with the state about the beacon block at the time of attestation.
pub previous_epoch_head_attesters: u64,
}
/// Summarised information about validator participation in the _previous and _current_ epochs of
/// some `BeaconState`.
#[derive(Clone)]
pub struct ValidatorStatuses {
statuses: Vec<AttesterStatus>,
/// Information about each individual validator from the state's validator registy.
pub statuses: Vec<AttesterStatus>,
/// Summed balances for various sets of validators.
pub total_balances: TotalBalances,
}
impl ValidatorStatuses {
/// Initializes a new instance, determining:
///
/// - Active validators
/// - Total balances for the current and previous epochs.
///
/// Spec v0.4.0
pub fn new(state: &BeaconState, spec: &ChainSpec) -> Self {
let mut statuses = Vec::with_capacity(state.validator_registry.len());
let mut total_balances = TotalBalances::default();
@ -116,10 +174,10 @@ impl ValidatorStatuses {
}
}
pub fn get(&self, i: usize) -> &AttesterStatus {
&self.statuses[i]
}
/// Process some attestations from the given `state` updating the `statuses` and
/// `total_balances` fields.
///
/// Spec v0.4.0
pub fn process_attestations(
&mut self,
state: &BeaconState,
@ -174,6 +232,10 @@ impl ValidatorStatuses {
Ok(())
}
/// Update the `statuses` for each validator based upon whether or not they attested to the
/// "winning" shard block root for the previous epoch.
///
/// Spec v0.4.0
pub fn process_winning_roots(
&mut self,
state: &BeaconState,
@ -207,6 +269,10 @@ impl ValidatorStatuses {
}
}
/// Returns the distance between when the attestation was created and when it was included in a
/// block.
///
/// Spec v0.4.0
fn inclusion_distance(a: &PendingAttestation) -> Slot {
a.inclusion_slot - a.data.slot
}