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beacon_chain.rs
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beacon_chain.rs
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use crate::attestation_verification::{
Error as AttestationError, SignatureVerifiedAttestation, VerifiedAggregatedAttestation,
VerifiedUnaggregatedAttestation,
};
use crate::beacon_proposer_cache::BeaconProposerCache;
use crate::block_verification::{
check_block_is_finalized_descendant, check_block_relevancy, get_block_root,
signature_verify_chain_segment, BlockError, FullyVerifiedBlock, GossipVerifiedBlock,
IntoFullyVerifiedBlock,
};
use crate::chain_config::ChainConfig;
use crate::errors::{BeaconChainError as Error, BlockProductionError};
use crate::eth1_chain::{Eth1Chain, Eth1ChainBackend};
use crate::events::ServerSentEventHandler;
use crate::head_tracker::HeadTracker;
use crate::migrate::BackgroundMigrator;
use crate::naive_aggregation_pool::{Error as NaiveAggregationError, NaiveAggregationPool};
use crate::observed_attestations::{Error as AttestationObservationError, ObservedAttestations};
use crate::observed_attesters::{ObservedAggregators, ObservedAttesters};
use crate::observed_block_producers::ObservedBlockProducers;
use crate::observed_operations::{ObservationOutcome, ObservedOperations};
use crate::persisted_beacon_chain::{PersistedBeaconChain, DUMMY_CANONICAL_HEAD_BLOCK_ROOT};
use crate::persisted_fork_choice::PersistedForkChoice;
use crate::shuffling_cache::{BlockShufflingIds, ShufflingCache};
use crate::snapshot_cache::SnapshotCache;
use crate::timeout_rw_lock::TimeoutRwLock;
use crate::validator_monitor::{
get_block_delay_ms, get_slot_delay_ms, timestamp_now, ValidatorMonitor,
HISTORIC_EPOCHS as VALIDATOR_MONITOR_HISTORIC_EPOCHS,
};
use crate::validator_pubkey_cache::ValidatorPubkeyCache;
use crate::BeaconForkChoiceStore;
use crate::BeaconSnapshot;
use crate::{metrics, BeaconChainError};
use eth2::types::{EventKind, SseBlock, SseFinalizedCheckpoint, SseHead};
use fork_choice::ForkChoice;
use futures::channel::mpsc::Sender;
use itertools::process_results;
use operation_pool::{OperationPool, PersistedOperationPool};
use parking_lot::{Mutex, RwLock};
use slasher::Slasher;
use slog::{crit, debug, error, info, trace, warn, Logger};
use slot_clock::SlotClock;
use state_processing::{
common::get_indexed_attestation,
per_block_processing,
per_block_processing::errors::AttestationValidationError,
per_slot_processing,
state_advance::{complete_state_advance, partial_state_advance},
BlockSignatureStrategy, SigVerifiedOp,
};
use std::borrow::Cow;
use std::cmp::Ordering;
use std::collections::HashMap;
use std::collections::HashSet;
use std::io::prelude::*;
use std::sync::Arc;
use std::time::{Duration, Instant};
use store::iter::{BlockRootsIterator, ParentRootBlockIterator, StateRootsIterator};
use store::{Error as DBError, HotColdDB, KeyValueStore, KeyValueStoreOp, StoreItem, StoreOp};
use types::beacon_state::CloneConfig;
use types::*;
pub type ForkChoiceError = fork_choice::Error<crate::ForkChoiceStoreError>;
/// The time-out before failure during an operation to take a read/write RwLock on the canonical
/// head.
pub const HEAD_LOCK_TIMEOUT: Duration = Duration::from_secs(1);
/// The time-out before failure during an operation to take a read/write RwLock on the block
/// processing cache.
pub const BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1);
/// The time-out before failure during an operation to take a read/write RwLock on the
/// attestation cache.
pub const ATTESTATION_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1);
/// The time-out before failure during an operation to take a read/write RwLock on the
/// validator pubkey cache.
pub const VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT: Duration = Duration::from_secs(1);
// These keys are all zero because they get stored in different columns, see `DBColumn` type.
pub const BEACON_CHAIN_DB_KEY: Hash256 = Hash256::zero();
pub const OP_POOL_DB_KEY: Hash256 = Hash256::zero();
pub const ETH1_CACHE_DB_KEY: Hash256 = Hash256::zero();
pub const FORK_CHOICE_DB_KEY: Hash256 = Hash256::zero();
/// The result of a chain segment processing.
pub enum ChainSegmentResult<T: EthSpec> {
/// Processing this chain segment finished successfully.
Successful { imported_blocks: usize },
/// There was an error processing this chain segment. Before the error, some blocks could
/// have been imported.
Failed {
imported_blocks: usize,
error: BlockError<T>,
},
}
/// The accepted clock drift for nodes gossiping blocks and attestations. See:
///
/// https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/p2p-interface.md#configuration
pub const MAXIMUM_GOSSIP_CLOCK_DISPARITY: Duration = Duration::from_millis(500);
#[derive(Debug, PartialEq)]
pub enum AttestationProcessingOutcome {
Processed,
EmptyAggregationBitfield,
UnknownHeadBlock {
beacon_block_root: Hash256,
},
/// The attestation is attesting to a state that is later than itself. (Viz., attesting to the
/// future).
AttestsToFutureBlock {
block: Slot,
attestation: Slot,
},
/// The slot is finalized, no need to import.
FinalizedSlot {
attestation: Slot,
finalized: Slot,
},
FutureEpoch {
attestation_epoch: Epoch,
current_epoch: Epoch,
},
PastEpoch {
attestation_epoch: Epoch,
current_epoch: Epoch,
},
BadTargetEpoch,
UnknownTargetRoot(Hash256),
InvalidSignature,
NoCommitteeForSlotAndIndex {
slot: Slot,
index: CommitteeIndex,
},
Invalid(AttestationValidationError),
}
/// Defines how a `BeaconState` should be "skipped" through skip-slots.
pub enum StateSkipConfig {
/// Calculate the state root during each skip slot, producing a fully-valid `BeaconState`.
WithStateRoots,
/// Don't calculate the state root at each slot, instead just use the zero hash. This is orders
/// of magnitude faster, however it produces a partially invalid state.
///
/// This state is useful for operations that don't use the state roots; e.g., for calculating
/// the shuffling.
WithoutStateRoots,
}
#[derive(Debug, PartialEq)]
pub struct HeadInfo {
pub slot: Slot,
pub block_root: Hash256,
pub state_root: Hash256,
pub current_justified_checkpoint: types::Checkpoint,
pub finalized_checkpoint: types::Checkpoint,
pub fork: Fork,
pub genesis_time: u64,
pub genesis_validators_root: Hash256,
pub proposer_shuffling_decision_root: Hash256,
}
pub trait BeaconChainTypes: Send + Sync + 'static {
type HotStore: store::ItemStore<Self::EthSpec>;
type ColdStore: store::ItemStore<Self::EthSpec>;
type SlotClock: slot_clock::SlotClock;
type Eth1Chain: Eth1ChainBackend<Self::EthSpec>;
type EthSpec: types::EthSpec;
}
pub type BeaconForkChoice<T> = ForkChoice<
BeaconForkChoiceStore<
<T as BeaconChainTypes>::EthSpec,
<T as BeaconChainTypes>::HotStore,
<T as BeaconChainTypes>::ColdStore,
>,
<T as BeaconChainTypes>::EthSpec,
>;
pub type BeaconStore<T> = Arc<
HotColdDB<
<T as BeaconChainTypes>::EthSpec,
<T as BeaconChainTypes>::HotStore,
<T as BeaconChainTypes>::ColdStore,
>,
>;
/// Represents the "Beacon Chain" component of Ethereum 2.0. Allows import of blocks and block
/// operations and chooses a canonical head.
pub struct BeaconChain<T: BeaconChainTypes> {
pub spec: ChainSpec,
/// Configuration for `BeaconChain` runtime behaviour.
pub config: ChainConfig,
/// Persistent storage for blocks, states, etc. Typically an on-disk store, such as LevelDB.
pub store: BeaconStore<T>,
/// Database migrator for running background maintenance on the store.
pub store_migrator: BackgroundMigrator<T::EthSpec, T::HotStore, T::ColdStore>,
/// Reports the current slot, typically based upon the system clock.
pub slot_clock: T::SlotClock,
/// Stores all operations (e.g., `Attestation`, `Deposit`, etc) that are candidates for
/// inclusion in a block.
pub op_pool: OperationPool<T::EthSpec>,
/// A pool of attestations dedicated to the "naive aggregation strategy" defined in the eth2
/// specs.
///
/// This pool accepts `Attestation` objects that only have one aggregation bit set and provides
/// a method to get an aggregated `Attestation` for some `AttestationData`.
pub naive_aggregation_pool: RwLock<NaiveAggregationPool<T::EthSpec>>,
/// Contains a store of attestations which have been observed by the beacon chain.
pub(crate) observed_attestations: RwLock<ObservedAttestations<T::EthSpec>>,
/// Maintains a record of which validators have been seen to attest in recent epochs.
pub(crate) observed_attesters: RwLock<ObservedAttesters<T::EthSpec>>,
/// Maintains a record of which validators have been seen to create `SignedAggregateAndProofs`
/// in recent epochs.
pub(crate) observed_aggregators: RwLock<ObservedAggregators<T::EthSpec>>,
/// Maintains a record of which validators have proposed blocks for each slot.
pub(crate) observed_block_producers: RwLock<ObservedBlockProducers<T::EthSpec>>,
/// Maintains a record of which validators have submitted voluntary exits.
pub(crate) observed_voluntary_exits: Mutex<ObservedOperations<SignedVoluntaryExit, T::EthSpec>>,
/// Maintains a record of which validators we've seen proposer slashings for.
pub(crate) observed_proposer_slashings: Mutex<ObservedOperations<ProposerSlashing, T::EthSpec>>,
/// Maintains a record of which validators we've seen attester slashings for.
pub(crate) observed_attester_slashings:
Mutex<ObservedOperations<AttesterSlashing<T::EthSpec>, T::EthSpec>>,
/// Provides information from the Ethereum 1 (PoW) chain.
pub eth1_chain: Option<Eth1Chain<T::Eth1Chain, T::EthSpec>>,
/// Stores a "snapshot" of the chain at the time the head-of-the-chain block was received.
pub(crate) canonical_head: TimeoutRwLock<BeaconSnapshot<T::EthSpec>>,
/// The root of the genesis block.
pub genesis_block_root: Hash256,
/// The root of the genesis state.
pub genesis_state_root: Hash256,
/// The root of the list of genesis validators, used during syncing.
pub genesis_validators_root: Hash256,
/// A state-machine that is updated with information from the network and chooses a canonical
/// head block.
pub fork_choice: RwLock<BeaconForkChoice<T>>,
/// A handler for events generated by the beacon chain. This is only initialized when the
/// HTTP server is enabled.
pub event_handler: Option<ServerSentEventHandler<T::EthSpec>>,
/// Used to track the heads of the beacon chain.
pub(crate) head_tracker: Arc<HeadTracker>,
/// A cache dedicated to block processing.
pub(crate) snapshot_cache: TimeoutRwLock<SnapshotCache<T::EthSpec>>,
/// Caches the attester shuffling for a given epoch and shuffling key root.
pub(crate) shuffling_cache: TimeoutRwLock<ShufflingCache>,
/// Caches the beacon block proposer shuffling for a given epoch and shuffling key root.
pub beacon_proposer_cache: Mutex<BeaconProposerCache>,
/// Caches a map of `validator_index -> validator_pubkey`.
pub(crate) validator_pubkey_cache: TimeoutRwLock<ValidatorPubkeyCache<T>>,
/// A list of any hard-coded forks that have been disabled.
pub disabled_forks: Vec<String>,
/// Sender given to tasks, so that if they encounter a state in which execution cannot
/// continue they can request that everything shuts down.
pub shutdown_sender: Sender<&'static str>,
/// Logging to CLI, etc.
pub(crate) log: Logger,
/// Arbitrary bytes included in the blocks.
pub(crate) graffiti: Graffiti,
/// Optional slasher.
pub slasher: Option<Arc<Slasher<T::EthSpec>>>,
/// Provides monitoring of a set of explicitly defined validators.
pub validator_monitor: RwLock<ValidatorMonitor<T::EthSpec>>,
}
type BeaconBlockAndState<T> = (BeaconBlock<T>, BeaconState<T>);
impl<T: BeaconChainTypes> BeaconChain<T> {
/// Persists the head tracker and fork choice.
///
/// We do it atomically even though no guarantees need to be made about blocks from
/// the head tracker also being present in fork choice.
pub fn persist_head_and_fork_choice(&self) -> Result<(), Error> {
let mut batch = vec![];
let _head_timer = metrics::start_timer(&metrics::PERSIST_HEAD);
batch.push(self.persist_head_in_batch());
let _fork_choice_timer = metrics::start_timer(&metrics::PERSIST_FORK_CHOICE);
batch.push(self.persist_fork_choice_in_batch());
self.store.hot_db.do_atomically(batch)?;
Ok(())
}
/// Return a `PersistedBeaconChain` representing the current head.
pub fn make_persisted_head(&self) -> PersistedBeaconChain {
PersistedBeaconChain {
_canonical_head_block_root: DUMMY_CANONICAL_HEAD_BLOCK_ROOT,
genesis_block_root: self.genesis_block_root,
ssz_head_tracker: self.head_tracker.to_ssz_container(),
}
}
/// Return a database operation for writing the beacon chain head to disk.
pub fn persist_head_in_batch(&self) -> KeyValueStoreOp {
self.make_persisted_head()
.as_kv_store_op(BEACON_CHAIN_DB_KEY)
}
/// Return a database operation for writing fork choice to disk.
pub fn persist_fork_choice_in_batch(&self) -> KeyValueStoreOp {
let fork_choice = self.fork_choice.read();
let persisted_fork_choice = PersistedForkChoice {
fork_choice: fork_choice.to_persisted(),
fork_choice_store: fork_choice.fc_store().to_persisted(),
};
persisted_fork_choice.as_kv_store_op(FORK_CHOICE_DB_KEY)
}
/// Load fork choice from disk, returning `None` if it isn't found.
pub fn load_fork_choice(store: BeaconStore<T>) -> Result<Option<BeaconForkChoice<T>>, Error> {
let persisted_fork_choice =
match store.get_item::<PersistedForkChoice>(&FORK_CHOICE_DB_KEY)? {
Some(fc) => fc,
None => return Ok(None),
};
let fc_store =
BeaconForkChoiceStore::from_persisted(persisted_fork_choice.fork_choice_store, store)?;
Ok(Some(ForkChoice::from_persisted(
persisted_fork_choice.fork_choice,
fc_store,
)?))
}
/// Persists `self.op_pool` to disk.
///
/// ## Notes
///
/// This operation is typically slow and causes a lot of allocations. It should be used
/// sparingly.
pub fn persist_op_pool(&self) -> Result<(), Error> {
let _timer = metrics::start_timer(&metrics::PERSIST_OP_POOL);
self.store.put_item(
&OP_POOL_DB_KEY,
&PersistedOperationPool::from_operation_pool(&self.op_pool),
)?;
Ok(())
}
/// Persists `self.eth1_chain` and its caches to disk.
pub fn persist_eth1_cache(&self) -> Result<(), Error> {
let _timer = metrics::start_timer(&metrics::PERSIST_OP_POOL);
if let Some(eth1_chain) = self.eth1_chain.as_ref() {
self.store
.put_item(Ð1_CACHE_DB_KEY, ð1_chain.as_ssz_container())?;
}
Ok(())
}
/// Returns the slot _right now_ according to `self.slot_clock`. Returns `Err` if the slot is
/// unavailable.
///
/// The slot might be unavailable due to an error with the system clock, or if the present time
/// is before genesis (i.e., a negative slot).
pub fn slot(&self) -> Result<Slot, Error> {
self.slot_clock.now().ok_or(Error::UnableToReadSlot)
}
/// Returns the epoch _right now_ according to `self.slot_clock`. Returns `Err` if the epoch is
/// unavailable.
///
/// The epoch might be unavailable due to an error with the system clock, or if the present time
/// is before genesis (i.e., a negative epoch).
pub fn epoch(&self) -> Result<Epoch, Error> {
self.slot()
.map(|slot| slot.epoch(T::EthSpec::slots_per_epoch()))
}
/// Iterates across all `(block_root, slot)` pairs from the head of the chain (inclusive) to
/// the earliest reachable ancestor (may or may not be genesis).
///
/// ## Notes
///
/// `slot` always decreases by `1`.
/// - Skipped slots contain the root of the closest prior
/// non-skipped slot (identical to the way they are stored in `state.block_roots`) .
/// - Iterator returns `(Hash256, Slot)`.
/// - As this iterator starts at the `head` of the chain (viz., the best block), the first slot
/// returned may be earlier than the wall-clock slot.
pub fn rev_iter_block_roots(
&self,
) -> Result<impl Iterator<Item = Result<(Hash256, Slot), Error>>, Error> {
let head = self.head()?;
let iter = BlockRootsIterator::owned(self.store.clone(), head.beacon_state);
Ok(
std::iter::once(Ok((head.beacon_block_root, head.beacon_block.slot())))
.chain(iter)
.map(|result| result.map_err(|e| e.into())),
)
}
pub fn forwards_iter_block_roots(
&self,
start_slot: Slot,
) -> Result<impl Iterator<Item = Result<(Hash256, Slot), Error>>, Error> {
let local_head = self.head()?;
let iter = HotColdDB::forwards_block_roots_iterator(
self.store.clone(),
start_slot,
local_head.beacon_state,
local_head.beacon_block_root,
&self.spec,
)?;
Ok(iter.map(|result| result.map_err(Into::into)))
}
/// Traverse backwards from `block_root` to find the block roots of its ancestors.
///
/// ## Notes
///
/// `slot` always decreases by `1`.
/// - Skipped slots contain the root of the closest prior
/// non-skipped slot (identical to the way they are stored in `state.block_roots`) .
/// - Iterator returns `(Hash256, Slot)`.
/// - The provided `block_root` is included as the first item in the iterator.
pub fn rev_iter_block_roots_from(
&self,
block_root: Hash256,
) -> Result<impl Iterator<Item = Result<(Hash256, Slot), Error>>, Error> {
let block = self
.get_block(&block_root)?
.ok_or(Error::MissingBeaconBlock(block_root))?;
let state = self
.get_state(&block.state_root(), Some(block.slot()))?
.ok_or_else(|| Error::MissingBeaconState(block.state_root()))?;
let iter = BlockRootsIterator::owned(self.store.clone(), state);
Ok(std::iter::once(Ok((block_root, block.slot())))
.chain(iter)
.map(|result| result.map_err(|e| e.into())))
}
/// Traverse backwards from `block_root` to find the root of the ancestor block at `slot`.
pub fn get_ancestor_block_root(
&self,
block_root: Hash256,
slot: Slot,
) -> Result<Option<Hash256>, Error> {
process_results(self.rev_iter_block_roots_from(block_root)?, |mut iter| {
iter.find(|(_, ancestor_slot)| *ancestor_slot == slot)
.map(|(ancestor_block_root, _)| ancestor_block_root)
})
}
/// Iterates across all `(state_root, slot)` pairs from the head of the chain (inclusive) to
/// the earliest reachable ancestor (may or may not be genesis).
///
/// ## Notes
///
/// `slot` always decreases by `1`.
/// - Iterator returns `(Hash256, Slot)`.
/// - As this iterator starts at the `head` of the chain (viz., the best block), the first slot
/// returned may be earlier than the wall-clock slot.
pub fn rev_iter_state_roots(
&self,
) -> Result<impl Iterator<Item = Result<(Hash256, Slot), Error>>, Error> {
let head = self.head()?;
let head_slot = head.beacon_state.slot;
let head_state_root = head.beacon_state_root();
let iter = StateRootsIterator::owned(self.store.clone(), head.beacon_state);
let iter = std::iter::once(Ok((head_state_root, head_slot)))
.chain(iter)
.map(|result| result.map_err(Into::into));
Ok(iter)
}
/// As for `rev_iter_state_roots` but starting from an arbitrary `BeaconState`.
pub fn rev_iter_state_roots_from<'a>(
&self,
state_root: Hash256,
state: &'a BeaconState<T::EthSpec>,
) -> impl Iterator<Item = Result<(Hash256, Slot), Error>> + 'a {
std::iter::once(Ok((state_root, state.slot)))
.chain(StateRootsIterator::new(self.store.clone(), state))
.map(|result| result.map_err(Into::into))
}
/// Returns the block at the given slot, if any. Only returns blocks in the canonical chain.
///
/// ## Errors
///
/// May return a database error.
pub fn block_at_slot(
&self,
slot: Slot,
) -> Result<Option<SignedBeaconBlock<T::EthSpec>>, Error> {
let root = process_results(self.rev_iter_block_roots()?, |mut iter| {
iter.find(|(_, this_slot)| *this_slot == slot)
.map(|(root, _)| root)
})?;
if let Some(block_root) = root {
Ok(self.store.get_item(&block_root)?)
} else {
Ok(None)
}
}
/// Returns the block at the given slot, if any. Only returns blocks in the canonical chain.
///
/// ## Errors
///
/// May return a database error.
pub fn state_root_at_slot(&self, slot: Slot) -> Result<Option<Hash256>, Error> {
process_results(self.rev_iter_state_roots()?, |mut iter| {
iter.find(|(_, this_slot)| *this_slot == slot)
.map(|(root, _)| root)
})
}
/// Returns the block root at the given slot, if any. Only returns roots in the canonical chain.
///
/// ## Errors
///
/// May return a database error.
pub fn block_root_at_slot(&self, slot: Slot) -> Result<Option<Hash256>, Error> {
process_results(self.rev_iter_block_roots()?, |mut iter| {
iter.find(|(_, this_slot)| *this_slot == slot)
.map(|(root, _)| root)
})
}
/// Returns the block at the given root, if any.
///
/// ## Errors
///
/// May return a database error.
pub fn get_block(
&self,
block_root: &Hash256,
) -> Result<Option<SignedBeaconBlock<T::EthSpec>>, Error> {
Ok(self.store.get_block(block_root)?)
}
/// Returns the state at the given root, if any.
///
/// ## Errors
///
/// May return a database error.
pub fn get_state(
&self,
state_root: &Hash256,
slot: Option<Slot>,
) -> Result<Option<BeaconState<T::EthSpec>>, Error> {
Ok(self.store.get_state(state_root, slot)?)
}
/// Returns a `Checkpoint` representing the head block and state. Contains the "best block";
/// the head of the canonical `BeaconChain`.
///
/// It is important to note that the `beacon_state` returned may not match the present slot. It
/// is the state as it was when the head block was received, which could be some slots prior to
/// now.
pub fn head(&self) -> Result<BeaconSnapshot<T::EthSpec>, Error> {
self.with_head(|head| Ok(head.clone_with(CloneConfig::committee_caches_only())))
}
/// Apply a function to the canonical head without cloning it.
pub fn with_head<U, E>(
&self,
f: impl FnOnce(&BeaconSnapshot<T::EthSpec>) -> Result<U, E>,
) -> Result<U, E>
where
E: From<Error>,
{
let head_lock = self
.canonical_head
.try_read_for(HEAD_LOCK_TIMEOUT)
.ok_or(Error::CanonicalHeadLockTimeout)?;
f(&head_lock)
}
/// Returns the beacon block root at the head of the canonical chain.
///
/// See `Self::head` for more information.
pub fn head_beacon_block_root(&self) -> Result<Hash256, Error> {
self.with_head(|s| Ok(s.beacon_block_root))
}
/// Returns the beacon block at the head of the canonical chain.
///
/// See `Self::head` for more information.
pub fn head_beacon_block(&self) -> Result<SignedBeaconBlock<T::EthSpec>, Error> {
self.with_head(|s| Ok(s.beacon_block.clone()))
}
/// Returns the beacon state at the head of the canonical chain.
///
/// See `Self::head` for more information.
pub fn head_beacon_state(&self) -> Result<BeaconState<T::EthSpec>, Error> {
self.with_head(|s| {
Ok(s.beacon_state
.clone_with(CloneConfig::committee_caches_only()))
})
}
/// Returns info representing the head block and state.
///
/// A summarized version of `Self::head` that involves less cloning.
pub fn head_info(&self) -> Result<HeadInfo, Error> {
self.with_head(|head| {
let proposer_shuffling_decision_root = head
.beacon_state
.proposer_shuffling_decision_root(head.beacon_block_root)?;
Ok(HeadInfo {
slot: head.beacon_block.slot(),
block_root: head.beacon_block_root,
state_root: head.beacon_state_root(),
current_justified_checkpoint: head.beacon_state.current_justified_checkpoint,
finalized_checkpoint: head.beacon_state.finalized_checkpoint,
fork: head.beacon_state.fork,
genesis_time: head.beacon_state.genesis_time,
genesis_validators_root: head.beacon_state.genesis_validators_root,
proposer_shuffling_decision_root,
})
})
}
/// Returns the current heads of the `BeaconChain`. For the canonical head, see `Self::head`.
///
/// Returns `(block_root, block_slot)`.
pub fn heads(&self) -> Vec<(Hash256, Slot)> {
self.head_tracker.heads()
}
pub fn knows_head(&self, block_hash: &SignedBeaconBlockHash) -> bool {
self.head_tracker.contains_head((*block_hash).into())
}
/// Returns the `BeaconState` at the given slot.
///
/// Returns `None` when the state is not found in the database or there is an error skipping
/// to a future state.
pub fn state_at_slot(
&self,
slot: Slot,
config: StateSkipConfig,
) -> Result<BeaconState<T::EthSpec>, Error> {
let head_state = self.head()?.beacon_state;
match slot.cmp(&head_state.slot) {
Ordering::Equal => Ok(head_state),
Ordering::Greater => {
if slot > head_state.slot + T::EthSpec::slots_per_epoch() {
warn!(
self.log,
"Skipping more than an epoch";
"head_slot" => head_state.slot,
"request_slot" => slot
)
}
let start_slot = head_state.slot;
let task_start = Instant::now();
let max_task_runtime = Duration::from_secs(self.spec.seconds_per_slot);
let head_state_slot = head_state.slot;
let mut state = head_state;
let skip_state_root = match config {
StateSkipConfig::WithStateRoots => None,
StateSkipConfig::WithoutStateRoots => Some(Hash256::zero()),
};
while state.slot < slot {
// Do not allow and forward state skip that takes longer than the maximum task duration.
//
// This is a protection against nodes doing too much work when they're not synced
// to a chain.
if task_start + max_task_runtime < Instant::now() {
return Err(Error::StateSkipTooLarge {
start_slot,
requested_slot: slot,
max_task_runtime,
});
}
// Note: supplying some `state_root` when it is known would be a cheap and easy
// optimization.
match per_slot_processing(&mut state, skip_state_root, &self.spec) {
Ok(_) => (),
Err(e) => {
warn!(
self.log,
"Unable to load state at slot";
"error" => ?e,
"head_slot" => head_state_slot,
"requested_slot" => slot
);
return Err(Error::NoStateForSlot(slot));
}
};
}
Ok(state)
}
Ordering::Less => {
let state_root = process_results(self.rev_iter_state_roots()?, |iter| {
iter.take_while(|(_, current_slot)| *current_slot >= slot)
.find(|(_, current_slot)| *current_slot == slot)
.map(|(root, _slot)| root)
})?
.ok_or(Error::NoStateForSlot(slot))?;
Ok(self
.get_state(&state_root, Some(slot))?
.ok_or(Error::NoStateForSlot(slot))?)
}
}
}
/// Returns the `BeaconState` the current slot (viz., `self.slot()`).
///
/// - A reference to the head state (note: this keeps a read lock on the head, try to use
/// sparingly).
/// - The head state, but with skipped slots (for states later than the head).
///
/// Returns `None` when there is an error skipping to a future state or the slot clock cannot
/// be read.
pub fn wall_clock_state(&self) -> Result<BeaconState<T::EthSpec>, Error> {
self.state_at_slot(self.slot()?, StateSkipConfig::WithStateRoots)
}
/// Returns the slot of the highest block in the canonical chain.
pub fn best_slot(&self) -> Result<Slot, Error> {
self.canonical_head
.try_read_for(HEAD_LOCK_TIMEOUT)
.map(|head| head.beacon_block.slot())
.ok_or(Error::CanonicalHeadLockTimeout)
}
/// Returns the validator index (if any) for the given public key.
///
/// ## Notes
///
/// This query uses the `validator_pubkey_cache` which contains _all_ validators ever seen,
/// even if those validators aren't included in the head state. It is important to remember
/// that just because a validator exists here, it doesn't necessarily exist in all
/// `BeaconStates`.
///
/// ## Errors
///
/// May return an error if acquiring a read-lock on the `validator_pubkey_cache` times out.
pub fn validator_index(&self, pubkey: &PublicKeyBytes) -> Result<Option<usize>, Error> {
let pubkey_cache = self
.validator_pubkey_cache
.try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT)
.ok_or(Error::ValidatorPubkeyCacheLockTimeout)?;
Ok(pubkey_cache.get_index(pubkey))
}
/// Returns the validator pubkey (if any) for the given validator index.
///
/// ## Notes
///
/// This query uses the `validator_pubkey_cache` which contains _all_ validators ever seen,
/// even if those validators aren't included in the head state. It is important to remember
/// that just because a validator exists here, it doesn't necessarily exist in all
/// `BeaconStates`.
///
/// ## Errors
///
/// May return an error if acquiring a read-lock on the `validator_pubkey_cache` times out.
pub fn validator_pubkey(&self, validator_index: usize) -> Result<Option<PublicKey>, Error> {
let pubkey_cache = self
.validator_pubkey_cache
.try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT)
.ok_or(Error::ValidatorPubkeyCacheLockTimeout)?;
Ok(pubkey_cache.get(validator_index).cloned())
}
/// As per `Self::validator_pubkey`, but returns `PublicKeyBytes`.
pub fn validator_pubkey_bytes(
&self,
validator_index: usize,
) -> Result<Option<PublicKeyBytes>, Error> {
let pubkey_cache = self
.validator_pubkey_cache
.try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT)
.ok_or(Error::ValidatorPubkeyCacheLockTimeout)?;
Ok(pubkey_cache.get_pubkey_bytes(validator_index).copied())
}
/// As per `Self::validator_pubkey_bytes` but will resolve multiple indices at once to avoid
/// bouncing the read-lock on the pubkey cache.
///
/// Returns a map that may have a length less than `validator_indices.len()` if some indices
/// were unable to be resolved.
pub fn validator_pubkey_bytes_many(
&self,
validator_indices: &[usize],
) -> Result<HashMap<usize, PublicKeyBytes>, Error> {
let pubkey_cache = self
.validator_pubkey_cache
.try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT)
.ok_or(Error::ValidatorPubkeyCacheLockTimeout)?;
let mut map = HashMap::with_capacity(validator_indices.len());
for &validator_index in validator_indices {
if let Some(pubkey) = pubkey_cache.get_pubkey_bytes(validator_index) {
map.insert(validator_index, *pubkey);
}
}
Ok(map)
}
/// Returns the block canonical root of the current canonical chain at a given slot.
///
/// Returns `None` if the given slot doesn't exist in the chain.
pub fn root_at_slot(&self, target_slot: Slot) -> Result<Option<Hash256>, Error> {
process_results(self.rev_iter_block_roots()?, |mut iter| {
iter.find(|(_, slot)| *slot == target_slot)
.map(|(root, _)| root)
})
}
/// Returns the block canonical root of the current canonical chain at a given slot, starting from the given state.
///
/// Returns `None` if the given slot doesn't exist in the chain.
pub fn root_at_slot_from_state(
&self,
target_slot: Slot,
beacon_block_root: Hash256,
state: &BeaconState<T::EthSpec>,
) -> Result<Option<Hash256>, Error> {
let iter = BlockRootsIterator::new(self.store.clone(), state);
let iter_with_head = std::iter::once(Ok((beacon_block_root, state.slot)))
.chain(iter)
.map(|result| result.map_err(|e| e.into()));
process_results(iter_with_head, |mut iter| {
iter.find(|(_, slot)| *slot == target_slot)
.map(|(root, _)| root)
})
}
/// Returns the attestation duties for the given validator indices using the shuffling cache.
///
/// An error may be returned if `head_block_root` is a finalized block, this function is only
/// designed for operations at the head of the chain.
///
/// The returned `Vec` will have the same length as `validator_indices`, any
/// non-existing/inactive validators will have `None` values.
///
/// ## Notes
///
/// This function will try to use the shuffling cache to return the value. If the value is not
/// in the shuffling cache, it will be added. Care should be taken not to wash out the
/// shuffling cache with historical/useless values.
pub fn validator_attestation_duties(
&self,
validator_indices: &[u64],
epoch: Epoch,
head_block_root: Hash256,
) -> Result<(Vec<Option<AttestationDuty>>, Hash256), Error> {
self.with_committee_cache(head_block_root, epoch, |committee_cache, dependent_root| {
let duties = validator_indices
.iter()
.map(|validator_index| {
let validator_index = *validator_index as usize;
committee_cache.get_attestation_duties(validator_index)
})
.collect();
Ok((duties, dependent_root))
})
}
/// Returns an aggregated `Attestation`, if any, that has a matching `attestation.data`.
///
/// The attestation will be obtained from `self.naive_aggregation_pool`.
pub fn get_aggregated_attestation(
&self,
data: &AttestationData,
) -> Option<Attestation<T::EthSpec>> {
self.naive_aggregation_pool.read().get(data)
}
/// Returns an aggregated `Attestation`, if any, that has a matching
/// `attestation.data.tree_hash_root()`.
///
/// The attestation will be obtained from `self.naive_aggregation_pool`.
pub fn get_aggregated_attestation_by_slot_and_root(
&self,
slot: Slot,
attestation_data_root: &Hash256,
) -> Option<Attestation<T::EthSpec>> {
self.naive_aggregation_pool
.read()
.get_by_slot_and_root(slot, attestation_data_root)
}
/// Produce an unaggregated `Attestation` that is valid for the given `slot` and `index`.
///
/// The produced `Attestation` will not be valid until it has been signed by exactly one
/// validator that is in the committee for `slot` and `index` in the canonical chain.
///
/// Always attests to the canonical chain.
pub fn produce_unaggregated_attestation(
&self,
slot: Slot,
index: CommitteeIndex,
) -> Result<Attestation<T::EthSpec>, Error> {
// Note: we're taking a lock on the head. The work involved here should be trivial enough
// that the lock should not be held for long.
let head = self
.canonical_head
.try_read_for(HEAD_LOCK_TIMEOUT)
.ok_or(Error::CanonicalHeadLockTimeout)?;
if slot >= head.beacon_block.slot() {
self.produce_unaggregated_attestation_for_block(
slot,
index,
head.beacon_block_root,
Cow::Borrowed(&head.beacon_state),
head.beacon_state_root(),
)
} else {
// We disallow producing attestations *prior* to the current head since such an
// attestation would require loading a `BeaconState` from disk. Loading `BeaconState`
// from disk is very resource intensive and proposes a DoS risk from validator clients.
//
// Although we generally allow validator clients to do things that might harm us (i.e.,
// we trust them), sometimes we need to protect the BN from accidental errors which
// could cause it significant harm.
//
// This case is particularity harmful since the HTTP API can effectively call this
// function an unlimited amount of times. If `n` validators all happen to call it at
// the same time, we're going to load `n` states (and tree hash caches) into memory all
// at once. With `n >= 10` we're looking at hundreds of MB or GBs of RAM.
Err(Error::AttestingPriorToHead {
head_slot: head.beacon_block.slot(),
request_slot: slot,
})
}
}
/// Produces an "unaggregated" attestation for the given `slot` and `index` that attests to
/// `beacon_block_root`. The provided `state` should match the `block.state_root` for the
/// `block` identified by `beacon_block_root`.
///
/// The attestation doesn't _really_ have anything about it that makes it unaggregated per say,
/// however this function is only required in the context of forming an unaggregated
/// attestation. It would be an (undetectable) violation of the protocol to create a
/// `SignedAggregateAndProof` based upon the output of this function.
pub fn produce_unaggregated_attestation_for_block(
&self,
slot: Slot,
index: CommitteeIndex,
beacon_block_root: Hash256,
mut state: Cow<BeaconState<T::EthSpec>>,
state_root: Hash256,
) -> Result<Attestation<T::EthSpec>, Error> {
let epoch = slot.epoch(T::EthSpec::slots_per_epoch());
if state.slot > slot {
return Err(Error::CannotAttestToFutureState);
} else if state.current_epoch() < epoch {
let mut_state = state.to_mut();
// Only perform a "partial" state advance since we do not require the state roots to be
// accurate.
partial_state_advance(
mut_state,
Some(state_root),
epoch.start_slot(T::EthSpec::slots_per_epoch()),
&self.spec,
)?;
mut_state.build_committee_cache(RelativeEpoch::Current, &self.spec)?;
}
let committee_len = state.get_beacon_committee(slot, index)?.committee.len();
let target_slot = epoch.start_slot(T::EthSpec::slots_per_epoch());
let target_root = if state.slot <= target_slot {
beacon_block_root
} else {
*state.get_block_root(target_slot)?
};
Ok(Attestation {
aggregation_bits: BitList::with_capacity(committee_len)?,
data: AttestationData {
slot,
index,
beacon_block_root,