lighthouse/beacon_node/beacon_chain/src/eth1_chain.rs
2020-04-22 01:05:46 +10:00

1050 lines
36 KiB
Rust

use crate::metrics;
use eth1::{Config as Eth1Config, Eth1Block, Service as HttpService};
use eth2_hashing::hash;
use futures::Future;
use slog::{debug, error, trace, Logger};
use ssz::{Decode, Encode};
use ssz_derive::{Decode, Encode};
use state_processing::per_block_processing::get_new_eth1_data;
use std::cmp::Ordering;
use std::collections::HashMap;
use std::iter::DoubleEndedIterator;
use std::marker::PhantomData;
use std::sync::Arc;
use store::{DBColumn, Error as StoreError, SimpleStoreItem, Store};
use types::{
BeaconState, BeaconStateError, ChainSpec, Deposit, Eth1Data, EthSpec, Hash256, Slot, Unsigned,
DEPOSIT_TREE_DEPTH,
};
type BlockNumber = u64;
type Eth1DataVoteCount = HashMap<(Eth1Data, BlockNumber), u64>;
#[derive(Debug, PartialEq)]
pub enum Error {
/// Unable to return an Eth1Data for the given epoch.
EpochUnavailable,
/// An error from the backend service (e.g., the web3 data fetcher).
BackendError(String),
/// The deposit index of the state is higher than the deposit contract. This is a critical
/// consensus error.
DepositIndexTooHigh,
/// The current state was unable to return the root for the state at the start of the eth1
/// voting period.
UnableToGetPreviousStateRoot(BeaconStateError),
/// The state required to find the previous eth1 block was not found in the store.
PreviousStateNotInDB(Hash256),
/// There was an error accessing an object in the database.
StoreError(StoreError),
/// The eth1 head block at the start of the eth1 voting period is unknown.
///
/// The eth1 caches are likely stale.
UnknownVotingPeriodHead,
/// The block that was previously voted into the state is unknown.
///
/// The eth1 caches are stale, or a junk value was voted into the chain.
UnknownPreviousEth1BlockHash,
/// An arithmetic error occurred.
ArithError(safe_arith::ArithError),
}
impl From<safe_arith::ArithError> for Error {
fn from(e: safe_arith::ArithError) -> Self {
Self::ArithError(e)
}
}
#[derive(Encode, Decode, Clone)]
pub struct SszEth1 {
use_dummy_backend: bool,
backend_bytes: Vec<u8>,
}
impl SimpleStoreItem for SszEth1 {
fn db_column() -> DBColumn {
DBColumn::Eth1Cache
}
fn as_store_bytes(&self) -> Vec<u8> {
self.as_ssz_bytes()
}
fn from_store_bytes(bytes: &[u8]) -> Result<Self, StoreError> {
Self::from_ssz_bytes(bytes).map_err(Into::into)
}
}
/// Holds an `Eth1ChainBackend` and serves requests from the `BeaconChain`.
pub struct Eth1Chain<T, E, S>
where
T: Eth1ChainBackend<E, S>,
E: EthSpec,
S: Store<E>,
{
backend: T,
/// When `true`, the backend will be ignored and dummy data from the 2019 Canada interop method
/// will be used instead.
pub use_dummy_backend: bool,
_phantom: PhantomData<(E, S)>,
}
impl<T, E, S> Eth1Chain<T, E, S>
where
T: Eth1ChainBackend<E, S>,
E: EthSpec,
S: Store<E>,
{
pub fn new(backend: T) -> Self {
Self {
backend,
use_dummy_backend: false,
_phantom: PhantomData,
}
}
/// Returns the `Eth1Data` that should be included in a block being produced for the given
/// `state`.
pub fn eth1_data_for_block_production(
&self,
state: &BeaconState<E>,
spec: &ChainSpec,
) -> Result<Eth1Data, Error> {
if self.use_dummy_backend {
let dummy_backend: DummyEth1ChainBackend<E, S> = DummyEth1ChainBackend::default();
dummy_backend.eth1_data(state, spec)
} else {
self.backend.eth1_data(state, spec)
}
}
/// Returns a list of `Deposits` that may be included in a block.
///
/// Including all of the returned `Deposits` in a block should _not_ cause it to become
/// invalid (i.e., this function should respect the maximum).
///
/// `eth1_data_vote` is the `Eth1Data` that the block producer would include in their
/// block. This vote may change the `state.eth1_data` value, which would change the deposit
/// count and therefore change the output of this function.
pub fn deposits_for_block_inclusion(
&self,
state: &BeaconState<E>,
eth1_data_vote: &Eth1Data,
spec: &ChainSpec,
) -> Result<Vec<Deposit>, Error> {
if self.use_dummy_backend {
let dummy_backend: DummyEth1ChainBackend<E, S> = DummyEth1ChainBackend::default();
dummy_backend.queued_deposits(state, eth1_data_vote, spec)
} else {
self.backend.queued_deposits(state, eth1_data_vote, spec)
}
}
/// Instantiate `Eth1Chain` from a persisted `SszEth1`.
///
/// The `Eth1Chain` will have the same caches as the persisted `SszEth1`.
pub fn from_ssz_container(
ssz_container: &SszEth1,
config: Eth1Config,
store: Arc<S>,
log: &Logger,
) -> Result<Self, String> {
let backend =
Eth1ChainBackend::from_bytes(&ssz_container.backend_bytes, config, store, log.clone())?;
Ok(Self {
use_dummy_backend: ssz_container.use_dummy_backend,
backend,
_phantom: PhantomData,
})
}
/// Return a `SszEth1` containing the state of `Eth1Chain`.
pub fn as_ssz_container(&self) -> SszEth1 {
SszEth1 {
use_dummy_backend: self.use_dummy_backend,
backend_bytes: self.backend.as_bytes(),
}
}
/// Consumes `self`, returning the backend.
pub fn into_backend(self) -> T {
self.backend
}
}
pub trait Eth1ChainBackend<T: EthSpec, S: Store<T>>: Sized + Send + Sync {
/// Returns the `Eth1Data` that should be included in a block being produced for the given
/// `state`.
fn eth1_data(&self, beacon_state: &BeaconState<T>, spec: &ChainSpec)
-> Result<Eth1Data, Error>;
/// Returns all `Deposits` between `state.eth1_deposit_index` and
/// `state.eth1_data.deposit_count`.
///
/// # Note:
///
/// It is possible that not all returned `Deposits` can be included in a block. E.g., there may
/// be more than `MAX_DEPOSIT_COUNT` or the churn may be too high.
fn queued_deposits(
&self,
beacon_state: &BeaconState<T>,
eth1_data_vote: &Eth1Data,
spec: &ChainSpec,
) -> Result<Vec<Deposit>, Error>;
/// Encode the `Eth1ChainBackend` instance to bytes.
fn as_bytes(&self) -> Vec<u8>;
/// Create a `Eth1ChainBackend` instance given encoded bytes.
fn from_bytes(
bytes: &[u8],
config: Eth1Config,
store: Arc<S>,
log: Logger,
) -> Result<Self, String>;
}
/// Provides a simple, testing-only backend that generates deterministic, meaningless eth1 data.
///
/// Never creates deposits, therefore the validator set is static.
///
/// This was used in the 2019 Canada interop workshops.
pub struct DummyEth1ChainBackend<T: EthSpec, S: Store<T>>(PhantomData<(T, S)>);
impl<T: EthSpec, S: Store<T>> Eth1ChainBackend<T, S> for DummyEth1ChainBackend<T, S> {
/// Produce some deterministic junk based upon the current epoch.
fn eth1_data(&self, state: &BeaconState<T>, _spec: &ChainSpec) -> Result<Eth1Data, Error> {
let current_epoch = state.current_epoch();
let slots_per_voting_period = T::slots_per_eth1_voting_period() as u64;
let current_voting_period: u64 = current_epoch.as_u64() / slots_per_voting_period;
let deposit_root = hash(&int_to_bytes32(current_voting_period));
let block_hash = hash(&deposit_root);
Ok(Eth1Data {
deposit_root: Hash256::from_slice(&deposit_root),
deposit_count: state.eth1_deposit_index,
block_hash: Hash256::from_slice(&block_hash),
})
}
/// The dummy back-end never produces deposits.
fn queued_deposits(
&self,
_: &BeaconState<T>,
_: &Eth1Data,
_: &ChainSpec,
) -> Result<Vec<Deposit>, Error> {
Ok(vec![])
}
/// Return empty Vec<u8> for dummy backend.
fn as_bytes(&self) -> Vec<u8> {
Vec::new()
}
/// Create dummy eth1 backend.
fn from_bytes(
_bytes: &[u8],
_config: Eth1Config,
_store: Arc<S>,
_log: Logger,
) -> Result<Self, String> {
Ok(Self(PhantomData))
}
}
impl<T: EthSpec, S: Store<T>> Default for DummyEth1ChainBackend<T, S> {
fn default() -> Self {
Self(PhantomData)
}
}
/// Maintains a cache of eth1 blocks and deposits and provides functions to allow block producers
/// to include new deposits and vote on `Eth1Data`.
///
/// The `core` connects to some external eth1 client (e.g., Parity/Geth) and polls it for
/// information.
#[derive(Clone)]
pub struct CachingEth1Backend<T: EthSpec, S> {
pub core: HttpService,
store: Arc<S>,
log: Logger,
_phantom: PhantomData<T>,
}
impl<T: EthSpec, S: Store<T>> CachingEth1Backend<T, S> {
/// Instantiates `self` with empty caches.
///
/// Does not connect to the eth1 node or start any tasks to keep the cache updated.
pub fn new(config: Eth1Config, log: Logger, store: Arc<S>) -> Self {
Self {
core: HttpService::new(config, log.clone()),
store,
log,
_phantom: PhantomData,
}
}
/// Starts the routine which connects to the external eth1 node and updates the caches.
pub fn start(
&self,
exit: tokio::sync::oneshot::Receiver<()>,
) -> impl Future<Item = (), Error = ()> {
self.core.auto_update(exit)
}
/// Instantiates `self` from an existing service.
pub fn from_service(service: HttpService, store: Arc<S>) -> Self {
Self {
log: service.log.clone(),
core: service,
store,
_phantom: PhantomData,
}
}
}
impl<T: EthSpec, S: Store<T>> Eth1ChainBackend<T, S> for CachingEth1Backend<T, S> {
fn eth1_data(&self, state: &BeaconState<T>, spec: &ChainSpec) -> Result<Eth1Data, Error> {
let period = T::SlotsPerEth1VotingPeriod::to_u64();
let voting_period_start_slot = (state.slot / period) * period;
let voting_period_start_seconds = slot_start_seconds::<T>(
state.genesis_time,
spec.milliseconds_per_slot,
voting_period_start_slot,
);
let blocks = self.core.blocks().read();
let votes_to_consider =
get_votes_to_consider(blocks.iter(), voting_period_start_seconds, spec);
trace!(
self.log,
"Found eth1 data votes_to_consider";
"votes_to_consider" => votes_to_consider.len(),
);
let valid_votes = collect_valid_votes(state, &votes_to_consider);
let eth1_data = if let Some(eth1_data) = find_winning_vote(valid_votes) {
eth1_data
} else {
// In this case, there are no valid votes available.
//
// Here we choose the eth1_data corresponding to the latest block in our voting window.
// If no votes exist, choose `state.eth1_data` as default vote.
let default_vote = votes_to_consider
.iter()
.max_by(|(_, x), (_, y)| x.cmp(y))
.map(|vote| {
let vote = vote.0.clone();
debug!(
self.log,
"No valid eth1_data votes";
"outcome" => "Casting vote corresponding to last candidate eth1 block",
);
vote
})
.unwrap_or_else(|| {
let vote = state.eth1_data.clone();
error!(
self.log,
"No valid eth1_data votes, `votes_to_consider` empty";
"lowest_block_number" => self.core.lowest_block_number(),
"earliest_block_timestamp" => self.core.earliest_block_timestamp(),
"genesis_time" => state.genesis_time,
"outcome" => "casting `state.eth1_data` as eth1 vote"
);
metrics::inc_counter(&metrics::DEFAULT_ETH1_VOTES);
vote
});
default_vote
};
debug!(
self.log,
"Produced vote for eth1 chain";
"deposit_root" => format!("{:?}", eth1_data.deposit_root),
"deposit_count" => eth1_data.deposit_count,
"block_hash" => format!("{:?}", eth1_data.block_hash),
);
Ok(eth1_data)
}
fn queued_deposits(
&self,
state: &BeaconState<T>,
eth1_data_vote: &Eth1Data,
_spec: &ChainSpec,
) -> Result<Vec<Deposit>, Error> {
let deposit_index = state.eth1_deposit_index;
let deposit_count = if let Some(new_eth1_data) = get_new_eth1_data(state, eth1_data_vote)? {
new_eth1_data.deposit_count
} else {
state.eth1_data.deposit_count
};
match deposit_index.cmp(&deposit_count) {
Ordering::Greater => Err(Error::DepositIndexTooHigh),
Ordering::Equal => Ok(vec![]),
Ordering::Less => {
let next = deposit_index;
let last = std::cmp::min(deposit_count, next + T::MaxDeposits::to_u64());
self.core
.deposits()
.read()
.cache
.get_deposits(next, last, deposit_count, DEPOSIT_TREE_DEPTH)
.map_err(|e| Error::BackendError(format!("Failed to get deposits: {:?}", e)))
.map(|(_deposit_root, deposits)| deposits)
}
}
}
/// Return encoded byte representation of the block and deposit caches.
fn as_bytes(&self) -> Vec<u8> {
self.core.as_bytes()
}
/// Recover the cached backend from encoded bytes.
fn from_bytes(
bytes: &[u8],
config: Eth1Config,
store: Arc<S>,
log: Logger,
) -> Result<Self, String> {
let inner = HttpService::from_bytes(bytes, config, log.clone())?;
Ok(Self {
core: inner,
store,
log,
_phantom: PhantomData,
})
}
}
/// Get all votes from eth1 blocks which are in the list of candidate blocks for the
/// current eth1 voting period.
///
/// Returns a hashmap of `Eth1Data` to its associated eth1 `block_number`.
fn get_votes_to_consider<'a, I>(
blocks: I,
voting_period_start_seconds: u64,
spec: &ChainSpec,
) -> HashMap<Eth1Data, u64>
where
I: DoubleEndedIterator<Item = &'a Eth1Block> + Clone,
{
blocks
.rev()
.skip_while(|eth1_block| !is_candidate_block(eth1_block, voting_period_start_seconds, spec))
.take_while(|eth1_block| is_candidate_block(eth1_block, voting_period_start_seconds, spec))
.filter_map(|eth1_block| {
eth1_block
.clone()
.eth1_data()
.map(|eth1_data| (eth1_data, eth1_block.number))
})
.collect()
}
/// Collect all valid votes that are cast during the current voting period.
/// Return hashmap with count of each vote cast.
fn collect_valid_votes<T: EthSpec>(
state: &BeaconState<T>,
votes_to_consider: &HashMap<Eth1Data, BlockNumber>,
) -> Eth1DataVoteCount {
let mut valid_votes = HashMap::new();
state
.eth1_data_votes
.iter()
.filter_map(|vote| {
if let Some(block_num) = votes_to_consider.get(vote) {
Some((vote.clone(), *block_num))
} else {
None
}
})
.for_each(|(eth1_data, block_number)| {
valid_votes
.entry((eth1_data, block_number))
.and_modify(|count| *count += 1)
.or_insert(1_u64);
});
valid_votes
}
/// Selects the winning vote from `valid_votes`.
fn find_winning_vote(valid_votes: Eth1DataVoteCount) -> Option<Eth1Data> {
valid_votes
.iter()
.max_by_key(|((_eth1_data, block_number), vote_count)| (*vote_count, block_number))
.map(|((eth1_data, _), _)| eth1_data.clone())
}
/// Returns `int` as little-endian bytes with a length of 32.
fn int_to_bytes32(int: u64) -> Vec<u8> {
let mut vec = int.to_le_bytes().to_vec();
vec.resize(32, 0);
vec
}
/// Returns the unix-epoch seconds at the start of the given `slot`.
fn slot_start_seconds<T: EthSpec>(
genesis_unix_seconds: u64,
milliseconds_per_slot: u64,
slot: Slot,
) -> u64 {
genesis_unix_seconds + slot.as_u64() * milliseconds_per_slot / 1_000
}
/// Returns a boolean denoting if a given `Eth1Block` is a candidate for `Eth1Data` calculation
/// at the timestamp `period_start`.
///
/// Note: `period_start` needs to be atleast (`spec.seconds_per_eth1_block * spec.eth1_follow_distance * 2`)
/// for this function to return meaningful values.
fn is_candidate_block(block: &Eth1Block, period_start: u64, spec: &ChainSpec) -> bool {
block.timestamp
<= period_start.saturating_sub(spec.seconds_per_eth1_block * spec.eth1_follow_distance)
&& block.timestamp
>= period_start
.saturating_sub(spec.seconds_per_eth1_block * spec.eth1_follow_distance * 2)
}
#[cfg(test)]
mod test {
use super::*;
use environment::null_logger;
use std::iter::FromIterator;
use types::{test_utils::DepositTestTask, MinimalEthSpec};
type E = MinimalEthSpec;
fn get_eth1_data(i: u64) -> Eth1Data {
Eth1Data {
block_hash: Hash256::from_low_u64_be(i),
deposit_root: Hash256::from_low_u64_be(u64::max_value() - i),
deposit_count: i,
}
}
fn get_voting_period_start_seconds(state: &BeaconState<E>, spec: &ChainSpec) -> u64 {
let period = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let voting_period_start_slot = (state.slot / period) * period;
slot_start_seconds::<E>(
state.genesis_time,
spec.milliseconds_per_slot,
voting_period_start_slot,
)
}
#[test]
fn slot_start_time() {
let zero_sec = 0;
assert_eq!(slot_start_seconds::<E>(100, zero_sec, Slot::new(2)), 100);
let half_sec = 500;
assert_eq!(slot_start_seconds::<E>(100, half_sec, Slot::new(0)), 100);
assert_eq!(slot_start_seconds::<E>(100, half_sec, Slot::new(1)), 100);
assert_eq!(slot_start_seconds::<E>(100, half_sec, Slot::new(2)), 101);
assert_eq!(slot_start_seconds::<E>(100, half_sec, Slot::new(3)), 101);
let one_sec = 1_000;
assert_eq!(slot_start_seconds::<E>(100, one_sec, Slot::new(0)), 100);
assert_eq!(slot_start_seconds::<E>(100, one_sec, Slot::new(1)), 101);
assert_eq!(slot_start_seconds::<E>(100, one_sec, Slot::new(2)), 102);
let three_sec = 3_000;
assert_eq!(slot_start_seconds::<E>(100, three_sec, Slot::new(0)), 100);
assert_eq!(slot_start_seconds::<E>(100, three_sec, Slot::new(1)), 103);
assert_eq!(slot_start_seconds::<E>(100, three_sec, Slot::new(2)), 106);
}
fn get_eth1_block(timestamp: u64, number: u64) -> Eth1Block {
Eth1Block {
number,
timestamp,
hash: Hash256::from_low_u64_be(number),
deposit_root: Some(Hash256::from_low_u64_be(number)),
deposit_count: Some(number),
}
}
mod eth1_chain_json_backend {
use super::*;
use eth1::DepositLog;
use store::MemoryStore;
use types::test_utils::{generate_deterministic_keypair, TestingDepositBuilder};
fn get_eth1_chain() -> Eth1Chain<CachingEth1Backend<E, MemoryStore<E>>, E, MemoryStore<E>> {
let eth1_config = Eth1Config {
..Eth1Config::default()
};
let log = null_logger().unwrap();
let store = Arc::new(MemoryStore::open());
Eth1Chain::new(CachingEth1Backend::new(eth1_config, log, store))
}
fn get_deposit_log(i: u64, spec: &ChainSpec) -> DepositLog {
let keypair = generate_deterministic_keypair(i as usize);
let mut builder =
TestingDepositBuilder::new(keypair.pk.clone(), spec.max_effective_balance);
builder.sign(DepositTestTask::Valid, &keypair, spec);
let deposit_data = builder.build().data;
DepositLog {
deposit_data,
block_number: i,
index: i,
}
}
#[test]
fn deposits_empty_cache() {
let spec = &E::default_spec();
let eth1_chain = get_eth1_chain();
assert_eq!(
eth1_chain.use_dummy_backend, false,
"test should not use dummy backend"
);
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), &spec);
state.eth1_deposit_index = 0;
state.eth1_data.deposit_count = 0;
assert!(
eth1_chain
.deposits_for_block_inclusion(&state, &Eth1Data::default(), spec)
.is_ok(),
"should succeed if cache is empty but no deposits are required"
);
state.eth1_data.deposit_count = 1;
assert!(
eth1_chain
.deposits_for_block_inclusion(&state, &Eth1Data::default(), spec)
.is_err(),
"should fail to get deposits if required, but cache is empty"
);
}
#[test]
fn deposits_with_cache() {
let spec = &E::default_spec();
let eth1_chain = get_eth1_chain();
let max_deposits = <E as EthSpec>::MaxDeposits::to_u64();
assert_eq!(
eth1_chain.use_dummy_backend, false,
"test should not use dummy backend"
);
let deposits: Vec<_> = (0..max_deposits + 2)
.map(|i| get_deposit_log(i, spec))
.inspect(|log| {
eth1_chain
.backend
.core
.deposits()
.write()
.cache
.insert_log(log.clone())
.expect("should insert log")
})
.collect();
assert_eq!(
eth1_chain.backend.core.deposits().write().cache.len(),
deposits.len(),
"cache should store all logs"
);
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), &spec);
state.eth1_deposit_index = 0;
state.eth1_data.deposit_count = 0;
assert!(
eth1_chain
.deposits_for_block_inclusion(&state, &Eth1Data::default(), spec)
.is_ok(),
"should succeed if no deposits are required"
);
(0..3).for_each(|initial_deposit_index| {
state.eth1_deposit_index = initial_deposit_index as u64;
(initial_deposit_index..deposits.len()).for_each(|i| {
state.eth1_data.deposit_count = i as u64;
let deposits_for_inclusion = eth1_chain
.deposits_for_block_inclusion(&state, &Eth1Data::default(), spec)
.unwrap_or_else(|_| panic!("should find deposit for {}", i));
let expected_len =
std::cmp::min(i - initial_deposit_index, max_deposits as usize);
assert_eq!(
deposits_for_inclusion.len(),
expected_len,
"should find {} deposits",
expected_len
);
let deposit_data_for_inclusion: Vec<_> = deposits_for_inclusion
.into_iter()
.map(|deposit| deposit.data)
.collect();
let expected_deposit_data: Vec<_> = deposits[initial_deposit_index
..std::cmp::min(initial_deposit_index + expected_len, deposits.len())]
.iter()
.map(|log| log.deposit_data.clone())
.collect();
assert_eq!(
deposit_data_for_inclusion, expected_deposit_data,
"should find the correct deposits for {}",
i
);
});
})
}
#[test]
fn eth1_data_empty_cache() {
let spec = &E::default_spec();
let eth1_chain = get_eth1_chain();
assert_eq!(
eth1_chain.use_dummy_backend, false,
"test should not use dummy backend"
);
let state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), &spec);
let a = eth1_chain
.eth1_data_for_block_production(&state, &spec)
.expect("should produce default eth1 data vote");
assert_eq!(
a, state.eth1_data,
"default vote should be same as state.eth1_data"
);
}
#[test]
fn default_vote() {
let spec = &E::default_spec();
let slots_per_eth1_voting_period = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let eth1_follow_distance = spec.eth1_follow_distance;
let eth1_chain = get_eth1_chain();
assert_eq!(
eth1_chain.use_dummy_backend, false,
"test should not use dummy backend"
);
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), &spec);
state.slot = Slot::from(slots_per_eth1_voting_period * 10);
let follow_distance_seconds = eth1_follow_distance * spec.seconds_per_eth1_block;
let voting_period_start = get_voting_period_start_seconds(&state, &spec);
let start_eth1_block = voting_period_start - follow_distance_seconds * 2;
let end_eth1_block = voting_period_start - follow_distance_seconds;
// Populate blocks cache with candidate eth1 blocks
let blocks = (start_eth1_block..end_eth1_block)
.map(|i| get_eth1_block(i, i))
.collect::<Vec<_>>();
blocks.iter().for_each(|block| {
eth1_chain
.backend
.core
.blocks()
.write()
.insert_root_or_child(block.clone())
.expect("should add blocks to cache");
});
let vote = eth1_chain
.eth1_data_for_block_production(&state, &spec)
.expect("should produce default eth1 data vote");
assert_eq!(
vote,
blocks
.last()
.expect("should have blocks")
.clone()
.eth1_data()
.expect("should have valid eth1 data"),
"default vote must correspond to last block in candidate blocks"
);
}
}
mod eth1_data_sets {
use super::*;
#[test]
fn empty_cache() {
let spec = &E::default_spec();
let state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), spec);
let blocks = vec![];
assert_eq!(
get_votes_to_consider(
blocks.iter(),
get_voting_period_start_seconds(&state, spec),
&spec,
),
HashMap::new()
);
}
#[test]
fn ideal_scenario() {
let spec = E::default_spec();
let slots_per_eth1_voting_period = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let eth1_follow_distance = spec.eth1_follow_distance;
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), &spec);
state.genesis_time = 0;
state.slot = Slot::from(slots_per_eth1_voting_period * 10);
let follow_distance_seconds = eth1_follow_distance * spec.seconds_per_eth1_block;
let voting_period_start = get_voting_period_start_seconds(&state, &spec);
let start_eth1_block = voting_period_start - follow_distance_seconds * 2;
let end_eth1_block = voting_period_start - follow_distance_seconds;
let blocks = (start_eth1_block..end_eth1_block)
.map(|i| get_eth1_block(i, i))
.collect::<Vec<_>>();
let votes_to_consider =
get_votes_to_consider(blocks.iter(), voting_period_start, &spec);
assert_eq!(
votes_to_consider.len() as u64,
end_eth1_block - start_eth1_block,
"all produced eth1 blocks should be in votes to consider"
);
(start_eth1_block..end_eth1_block)
.map(|i| get_eth1_block(i, i))
.for_each(|eth1_block| {
assert_eq!(
eth1_block.number,
*votes_to_consider
.get(&eth1_block.clone().eth1_data().unwrap())
.expect("votes_to_consider should have expected block numbers")
)
});
}
}
mod collect_valid_votes {
use super::*;
fn get_eth1_data_vec(n: u64, block_number_offset: u64) -> Vec<(Eth1Data, BlockNumber)> {
(0..n)
.map(|i| (get_eth1_data(i), i + block_number_offset))
.collect()
}
macro_rules! assert_votes {
($votes: expr, $expected: expr, $text: expr) => {
let expected: Vec<(Eth1Data, BlockNumber)> = $expected;
assert_eq!(
$votes.len(),
expected.len(),
"map should have the same number of elements"
);
expected.iter().for_each(|(eth1_data, block_number)| {
$votes
.get(&(eth1_data.clone(), *block_number))
.expect("should contain eth1 data");
})
};
}
#[test]
fn no_votes_in_state() {
let slots = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let spec = &E::default_spec();
let state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), spec);
let votes_to_consider = get_eth1_data_vec(slots, 0);
let votes = collect_valid_votes(
&state,
&HashMap::from_iter(votes_to_consider.clone().into_iter()),
);
assert_eq!(
votes.len(),
0,
"should not find any votes when state has no votes"
);
}
#[test]
fn distinct_votes_in_state() {
let slots = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let spec = &E::default_spec();
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), spec);
let votes_to_consider = get_eth1_data_vec(slots, 0);
state.eth1_data_votes = votes_to_consider[0..slots as usize / 4]
.iter()
.map(|(eth1_data, _)| eth1_data)
.cloned()
.collect::<Vec<_>>()
.into();
let votes = collect_valid_votes(
&state,
&HashMap::from_iter(votes_to_consider.clone().into_iter()),
);
assert_votes!(
votes,
votes_to_consider[0..slots as usize / 4].to_vec(),
"should find as many votes as were in the state"
);
}
#[test]
fn duplicate_votes_in_state() {
let slots = <E as EthSpec>::SlotsPerEth1VotingPeriod::to_u64();
let spec = &E::default_spec();
let mut state: BeaconState<E> = BeaconState::new(0, get_eth1_data(0), spec);
let votes_to_consider = get_eth1_data_vec(slots, 0);
let duplicate_eth1_data = votes_to_consider
.last()
.expect("should have some eth1 data")
.clone();
state.eth1_data_votes = vec![duplicate_eth1_data.clone(); 4]
.iter()
.map(|(eth1_data, _)| eth1_data)
.cloned()
.collect::<Vec<_>>()
.into();
let votes = collect_valid_votes(
&state,
&HashMap::from_iter(votes_to_consider.clone().into_iter()),
);
assert_votes!(
votes,
// There should only be one value if there's a duplicate
vec![duplicate_eth1_data.clone()],
"should find as many votes as were in the state"
);
assert_eq!(
*votes
.get(&duplicate_eth1_data)
.expect("should contain vote"),
4,
"should have four votes"
);
}
}
mod winning_vote {
use super::*;
type Vote = ((Eth1Data, u64), u64);
fn vote(block_number: u64, vote_count: u64) -> Vote {
(
(
Eth1Data {
deposit_root: Hash256::from_low_u64_be(block_number),
deposit_count: block_number,
block_hash: Hash256::from_low_u64_be(block_number),
},
block_number,
),
vote_count,
)
}
fn vote_data(vote: &Vote) -> Eth1Data {
(vote.0).0.clone()
}
#[test]
fn no_votes() {
let no_votes = vec![vote(0, 0), vote(1, 0), vote(3, 0), vote(2, 0)];
assert_eq!(
// Favour the highest block number when there are no votes.
vote_data(&no_votes[2]),
find_winning_vote(Eth1DataVoteCount::from_iter(no_votes.into_iter()))
.expect("should find winner")
);
}
#[test]
fn equal_votes() {
let votes = vec![vote(0, 1), vote(1, 1), vote(3, 1), vote(2, 1)];
assert_eq!(
// Favour the highest block number when there are equal votes.
vote_data(&votes[2]),
find_winning_vote(Eth1DataVoteCount::from_iter(votes.into_iter()))
.expect("should find winner")
);
}
#[test]
fn some_votes() {
let votes = vec![vote(0, 0), vote(1, 1), vote(3, 1), vote(2, 2)];
assert_eq!(
// Favour the highest vote over the highest block number.
vote_data(&votes[3]),
find_winning_vote(Eth1DataVoteCount::from_iter(votes.into_iter()))
.expect("should find winner")
);
}
#[test]
fn tying_votes() {
let votes = vec![vote(0, 0), vote(1, 1), vote(2, 2), vote(3, 2)];
assert_eq!(
// Favour the highest block number for tying votes.
vote_data(&votes[3]),
find_winning_vote(Eth1DataVoteCount::from_iter(votes.into_iter()))
.expect("should find winner")
);
}
#[test]
fn all_tying_votes() {
let votes = vec![vote(3, 42), vote(2, 42), vote(1, 42), vote(0, 42)];
assert_eq!(
// Favour the highest block number for tying votes.
vote_data(&votes[0]),
find_winning_vote(Eth1DataVoteCount::from_iter(votes.into_iter()))
.expect("should find winner")
);
}
}
}