Refactor beacon_chain.

Moves all the `BeaconChain` impls into the same file that the struct is
defined in.
This commit is contained in:
Paul Hauner 2019-02-05 03:52:47 +11:00
parent bd1cfeeba9
commit c1ed5cd2d8
No known key found for this signature in database
GPG Key ID: D362883A9218FCC6
14 changed files with 648 additions and 790 deletions

View File

@ -20,19 +20,18 @@ pub struct AttestationAggregator {
store: HashMap<Vec<u8>, Attestation>,
}
/// The outcome of sucessfully processing a `FreeAttestation`.
#[derive(Debug, PartialEq)]
pub enum ProcessOutcome {
pub struct Outcome {
pub valid: bool,
pub message: Message,
}
pub enum Message {
/// The free attestation was added to an existing attestation.
Aggregated,
/// The free attestation has already been aggregated to an existing attestation.
AggregationNotRequired,
/// The free attestation was transformed into a new attestation.
NewAttestationCreated,
}
#[derive(Debug, PartialEq)]
pub enum Error {
/// The supplied `validator_index` is not in the committee for the given `shard` and `slot`.
BadValidatorIndex,
/// The given `signature` did not match the `pubkey` in the given
@ -42,8 +41,20 @@ pub enum Error {
BadSlot,
/// The given `shard` does not match the validators committee assignment.
BadShard,
/// There was an error finding the committee for the given `validator_index`.
CommitteesError(CommitteesError),
}
macro_rules! some_or_invalid {
($expression: expr, $error: expr) => {
match $expression {
Some(x) => x,
None => {
return Ok(Outcome {
valid: false,
message: $error,
});
}
}
};
}
impl AttestationAggregator {
@ -66,33 +77,45 @@ impl AttestationAggregator {
state: &BeaconState,
free_attestation: &FreeAttestation,
spec: &ChainSpec,
) -> Result<ProcessOutcome, Error> {
let (slot, shard, committee_index) = state
.attestation_slot_and_shard_for_validator(
) -> Result<Outcome, CommitteesError> {
let (slot, shard, committee_index) = some_or_invalid!(
state.attestation_slot_and_shard_for_validator(
free_attestation.validator_index as usize,
spec,
)?
.ok_or_else(|| Error::BadValidatorIndex)?;
)?,
Message::BadValidatorIndex
);
if free_attestation.data.slot != slot {
return Err(Error::BadSlot);
return Ok(Outcome {
valid: false,
message: Message::BadSlot,
});
}
if free_attestation.data.shard != shard {
return Err(Error::BadShard);
return Ok(Outcome {
valid: false,
message: Message::BadShard,
});
}
let signable_message = free_attestation.data.signable_message(PHASE_0_CUSTODY_BIT);
let validator_pubkey = &state
.validator_registry
.get(free_attestation.validator_index as usize)
.ok_or_else(|| Error::BadValidatorIndex)?
.pubkey;
let validator_record = some_or_invalid!(
state
.validator_registry
.get(free_attestation.validator_index as usize),
Message::BadValidatorIndex
);
if !free_attestation
.signature
.verify(&signable_message, &validator_pubkey)
.verify(&signable_message, &validator_record.pubkey)
{
return Err(Error::BadSignature);
return Ok(Outcome {
valid: false,
message: Message::BadSignature,
});
}
if let Some(existing_attestation) = self.store.get(&signable_message) {
@ -102,9 +125,15 @@ impl AttestationAggregator {
committee_index as usize,
) {
self.store.insert(signable_message, updated_attestation);
Ok(ProcessOutcome::Aggregated)
Ok(Outcome {
valid: true,
message: Message::Aggregated,
})
} else {
Ok(ProcessOutcome::AggregationNotRequired)
Ok(Outcome {
valid: true,
message: Message::AggregationNotRequired,
})
}
} else {
let mut aggregate_signature = AggregateSignature::new();
@ -118,7 +147,10 @@ impl AttestationAggregator {
aggregate_signature,
};
self.store.insert(signable_message, new_attestation);
Ok(ProcessOutcome::NewAttestationCreated)
Ok(Outcome {
valid: true,
message: Message::NewAttestationCreated,
})
}
}
@ -183,9 +215,3 @@ fn aggregate_attestation(
})
}
}
impl From<CommitteesError> for Error {
fn from(e: CommitteesError) -> Error {
Error::CommitteesError(e)
}
}

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@ -1,35 +0,0 @@
use super::{BeaconChain, ClientDB, SlotClock};
pub use crate::attestation_aggregator::{Error as AggregatorError, ProcessOutcome};
use types::FreeAttestation;
#[derive(Debug, PartialEq)]
pub enum Error {
/// The free attestation was not processed succesfully.
AggregatorError(AggregatorError),
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Validate a `FreeAttestation` and either:
///
/// - Create a new `Attestation`.
/// - Aggregate it to an existing `Attestation`.
pub fn process_free_attestation(
&self,
free_attestation: FreeAttestation,
) -> Result<ProcessOutcome, Error> {
self.attestation_aggregator
.write()
.process_free_attestation(&self.state.read(), &free_attestation, &self.spec)
.map_err(|e| e.into())
}
}
impl From<AggregatorError> for Error {
fn from(e: AggregatorError) -> Error {
Error::AggregatorError(e)
}
}

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@ -1,48 +0,0 @@
use super::{BeaconChain, ClientDB, SlotClock};
use types::{AttestationData, Hash256};
#[derive(Debug, PartialEq)]
pub enum Error {
/// The `justified_block_root` is unknown. This is an internal error.
UnknownJustifiedRoot,
/// The `epoch_boundary_root` is unknown. This is an internal error.
UnknownBoundaryRoot,
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Produce an `AttestationData` that is valid for the present `slot` and given `shard`.
pub fn produce_attestation_data(&self, shard: u64) -> Result<AttestationData, Error> {
let justified_slot = self.justified_slot();
let justified_block_root = self
.state
.read()
.get_block_root(justified_slot, &self.spec)
.ok_or_else(|| Error::UnknownJustifiedRoot)?
.clone();
let epoch_boundary_root = self
.state
.read()
.get_block_root(
self.state.read().current_epoch_start_slot(&self.spec),
&self.spec,
)
.ok_or_else(|| Error::UnknownBoundaryRoot)?
.clone();
Ok(AttestationData {
slot: self.state.read().slot,
shard,
beacon_block_root: self.head().beacon_block_root.clone(),
epoch_boundary_root,
shard_block_root: Hash256::zero(),
latest_crosslink_root: Hash256::zero(),
justified_slot,
justified_block_root,
})
}
}

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@ -1,4 +1,3 @@
use crate::{BeaconChain, ClientDB, SlotClock};
use std::collections::HashMap;
use types::Hash256;
@ -21,23 +20,3 @@ impl AttestationTargets {
self.map.insert(validator_index, block_hash)
}
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
pub fn insert_latest_attestation_target(&self, validator_index: u64, block_root: Hash256) {
let mut targets = self.latest_attestation_targets.write();
targets.insert(validator_index, block_root);
}
pub fn get_latest_attestation_target(&self, validator_index: u64) -> Option<Hash256> {
let targets = self.latest_attestation_targets.read();
match targets.get(validator_index) {
Some(hash) => Some(hash.clone()),
None => None,
}
}
}

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@ -0,0 +1,586 @@
use db::{
stores::{BeaconBlockStore, BeaconStateStore},
ClientDB, DBError,
};
use genesis::{genesis_beacon_block, genesis_beacon_state};
use log::{debug, trace};
use parking_lot::{RwLock, RwLockReadGuard};
use slot_clock::SlotClock;
use ssz::ssz_encode;
use std::sync::Arc;
use types::{
beacon_state::{BlockProcessingError, CommitteesError, SlotProcessingError},
readers::{BeaconBlockReader, BeaconStateReader},
AttestationData, BeaconBlock, BeaconBlockBody, BeaconState, ChainSpec, Eth1Data,
FreeAttestation, Hash256, PublicKey, Signature,
};
use crate::attestation_aggregator::{AttestationAggregator, Outcome as AggregationOutcome};
use crate::attestation_targets::AttestationTargets;
use crate::block_graph::BlockGraph;
use crate::checkpoint::CheckPoint;
#[derive(Debug, PartialEq)]
pub enum Error {
InsufficientValidators,
BadRecentBlockRoots,
CommitteesError(CommitteesError),
DBInconsistent(String),
DBError(String),
}
#[derive(Debug, PartialEq)]
pub enum ValidBlock {
/// The block was sucessfully processed.
Processed,
}
#[derive(Debug, PartialEq)]
pub enum InvalidBlock {
/// The block slot is greater than the present slot.
FutureSlot,
/// The block state_root does not match the generated state.
StateRootMismatch,
/// The blocks parent_root is unknown.
ParentUnknown,
/// There was an error whilst advancing the parent state to the present slot. This condition
/// should not occur, it likely represents an internal error.
SlotProcessingError(SlotProcessingError),
/// The block could not be applied to the state, it is invalid.
PerBlockProcessingError(BlockProcessingError),
}
#[derive(Debug, PartialEq)]
pub enum BlockProcessingOutcome {
/// The block was sucessfully validated.
ValidBlock(ValidBlock),
/// The block was not sucessfully validated.
InvalidBlock(InvalidBlock),
}
pub struct BeaconChain<T: ClientDB + Sized, U: SlotClock> {
pub block_store: Arc<BeaconBlockStore<T>>,
pub state_store: Arc<BeaconStateStore<T>>,
pub slot_clock: U,
pub block_graph: BlockGraph,
pub attestation_aggregator: RwLock<AttestationAggregator>,
canonical_head: RwLock<CheckPoint>,
finalized_head: RwLock<CheckPoint>,
justified_head: RwLock<CheckPoint>,
pub state: RwLock<BeaconState>,
pub latest_attestation_targets: RwLock<AttestationTargets>,
pub spec: ChainSpec,
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Instantiate a new Beacon Chain, from genesis.
pub fn genesis(
state_store: Arc<BeaconStateStore<T>>,
block_store: Arc<BeaconBlockStore<T>>,
slot_clock: U,
spec: ChainSpec,
) -> Result<Self, Error> {
if spec.initial_validators.is_empty() {
return Err(Error::InsufficientValidators);
}
let genesis_state = genesis_beacon_state(&spec);
let state_root = genesis_state.canonical_root();
state_store.put(&state_root, &ssz_encode(&genesis_state)[..])?;
let genesis_block = genesis_beacon_block(state_root, &spec);
let block_root = genesis_block.canonical_root();
block_store.put(&block_root, &ssz_encode(&genesis_block)[..])?;
let block_graph = BlockGraph::new();
block_graph.add_leaf(&Hash256::zero(), block_root.clone());
let finalized_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let justified_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let canonical_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let attestation_aggregator = RwLock::new(AttestationAggregator::new());
let latest_attestation_targets = RwLock::new(AttestationTargets::new());
Ok(Self {
block_store,
state_store,
slot_clock,
block_graph,
attestation_aggregator,
state: RwLock::new(genesis_state.clone()),
justified_head,
finalized_head,
canonical_head,
latest_attestation_targets,
spec: spec,
})
}
/// Update the canonical head to some new values.
pub fn update_canonical_head(
&self,
new_beacon_block: BeaconBlock,
new_beacon_block_root: Hash256,
new_beacon_state: BeaconState,
new_beacon_state_root: Hash256,
) {
let mut head = self.canonical_head.write();
head.update(
new_beacon_block,
new_beacon_block_root,
new_beacon_state,
new_beacon_state_root,
);
}
/// Returns a read-lock guarded `CheckPoint` struct for reading the head (as chosen by the
/// fork-choice rule).
///
/// 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 recieved, which could be some slots prior to
/// now.
pub fn head(&self) -> RwLockReadGuard<CheckPoint> {
self.canonical_head.read()
}
/// Update the justified head to some new values.
pub fn update_finalized_head(
&self,
new_beacon_block: BeaconBlock,
new_beacon_block_root: Hash256,
new_beacon_state: BeaconState,
new_beacon_state_root: Hash256,
) {
let mut finalized_head = self.finalized_head.write();
finalized_head.update(
new_beacon_block,
new_beacon_block_root,
new_beacon_state,
new_beacon_state_root,
);
}
/// Returns a read-lock guarded `CheckPoint` struct for reading the justified head (as chosen,
/// indirectly, by the fork-choice rule).
pub fn finalized_head(&self) -> RwLockReadGuard<CheckPoint> {
self.finalized_head.read()
}
/// Advance the `self.state` `BeaconState` to the supplied slot.
///
/// This will perform per_slot and per_epoch processing as required.
///
/// The `previous_block_root` will be set to the root of the current head block (as determined
/// by the fork-choice rule).
///
/// It is important to note that this is _not_ the state corresponding to the canonical head
/// block, instead it is that state which may or may not have had additional per slot/epoch
/// processing applied to it.
pub fn advance_state(&self, slot: u64) -> Result<(), SlotProcessingError> {
let state_slot = self.state.read().slot;
let head_block_root = self.head().beacon_block_root;
for _ in state_slot..slot {
self.state
.write()
.per_slot_processing(head_block_root.clone(), &self.spec)?;
}
Ok(())
}
/// Returns the the validator index (if any) for the given public key.
///
/// Information is retrieved from the present `beacon_state.validator_registry`.
pub fn validator_index(&self, pubkey: &PublicKey) -> Option<usize> {
for (i, validator) in self
.head()
.beacon_state
.validator_registry
.iter()
.enumerate()
{
if validator.pubkey == *pubkey {
return Some(i);
}
}
None
}
/// Returns the number of slots the validator has been required to propose.
///
/// Returns `None` if the `validator_index` is invalid.
///
/// Information is retrieved from the present `beacon_state.validator_registry`.
pub fn proposer_slots(&self, validator_index: usize) -> Option<u64> {
if let Some(validator) = self.state.read().validator_registry.get(validator_index) {
Some(validator.proposer_slots)
} else {
None
}
}
/// Reads the slot clock, returns `None` 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).
///
/// This is distinct to `present_slot`, which simply reads the latest state. If a
/// call to `read_slot_clock` results in a higher slot than a call to `present_slot`,
/// `self.state` should undergo per slot processing.
pub fn read_slot_clock(&self) -> Option<u64> {
match self.slot_clock.present_slot() {
Ok(some_slot) => some_slot,
_ => None,
}
}
/// Returns slot of the present state.
///
/// This is distinct to `read_slot_clock`, which reads from the actual system clock. If
/// `self.state` has not been transitioned it is possible for the system clock to be on a
/// different slot to what is returned from this call.
pub fn present_slot(&self) -> u64 {
self.state.read().slot
}
/// Returns the block proposer for a given slot.
///
/// Information is read from the present `beacon_state` shuffling, so only information from the
/// present and prior epoch is available.
pub fn block_proposer(&self, slot: u64) -> Result<usize, CommitteesError> {
let index = self
.state
.read()
.get_beacon_proposer_index(slot, &self.spec)?;
Ok(index)
}
/// Returns the justified slot for the present state.
pub fn justified_slot(&self) -> u64 {
self.state.read().justified_slot
}
/// Returns the attestation slot and shard for a given validator index.
///
/// Information is read from the current state, so only information from the present and prior
/// epoch is available.
pub fn validator_attestion_slot_and_shard(
&self,
validator_index: usize,
) -> Result<Option<(u64, u64)>, CommitteesError> {
if let Some((slot, shard, _committee)) = self
.state
.read()
.attestation_slot_and_shard_for_validator(validator_index, &self.spec)?
{
Ok(Some((slot, shard)))
} else {
Ok(None)
}
}
/// Produce an `AttestationData` that is valid for the present `slot` and given `shard`.
pub fn produce_attestation_data(&self, shard: u64) -> Result<AttestationData, Error> {
let justified_slot = self.justified_slot();
let justified_block_root = self
.state
.read()
.get_block_root(justified_slot, &self.spec)
.ok_or_else(|| Error::BadRecentBlockRoots)?
.clone();
let epoch_boundary_root = self
.state
.read()
.get_block_root(
self.state.read().current_epoch_start_slot(&self.spec),
&self.spec,
)
.ok_or_else(|| Error::BadRecentBlockRoots)?
.clone();
Ok(AttestationData {
slot: self.state.read().slot,
shard,
beacon_block_root: self.head().beacon_block_root.clone(),
epoch_boundary_root,
shard_block_root: Hash256::zero(),
latest_crosslink_root: Hash256::zero(),
justified_slot,
justified_block_root,
})
}
/// Validate a `FreeAttestation` and either:
///
/// - Create a new `Attestation`.
/// - Aggregate it to an existing `Attestation`.
pub fn process_free_attestation(
&self,
free_attestation: FreeAttestation,
) -> Result<AggregationOutcome, Error> {
self.attestation_aggregator
.write()
.process_free_attestation(&self.state.read(), &free_attestation, &self.spec)
.map_err(|e| e.into())
}
/// Set the latest attestation target for some validator.
pub fn insert_latest_attestation_target(&self, validator_index: u64, block_root: Hash256) {
let mut targets = self.latest_attestation_targets.write();
targets.insert(validator_index, block_root);
}
/// Get the latest attestation target for some validator.
pub fn get_latest_attestation_target(&self, validator_index: u64) -> Option<Hash256> {
let targets = self.latest_attestation_targets.read();
match targets.get(validator_index) {
Some(hash) => Some(hash.clone()),
None => None,
}
}
/// Dumps the entire canonical chain, from the head to genesis to a vector for analysis.
///
/// This could be a very expensive operation and should only be done in testing/analysis
/// activities.
pub fn chain_dump(&self) -> Result<Vec<CheckPoint>, Error> {
let mut dump = vec![];
let mut last_slot = CheckPoint {
beacon_block: self.head().beacon_block.clone(),
beacon_block_root: self.head().beacon_block_root,
beacon_state: self.head().beacon_state.clone(),
beacon_state_root: self.head().beacon_state_root,
};
dump.push(last_slot.clone());
loop {
let beacon_block_root = last_slot.beacon_block.parent_root;
if beacon_block_root == self.spec.zero_hash {
break; // Genesis has been reached.
}
let beacon_block = self
.block_store
.get_deserialized(&beacon_block_root)?
.ok_or_else(|| {
Error::DBInconsistent(format!("Missing block {}", beacon_block_root))
})?;
let beacon_state_root = beacon_block.state_root;
let beacon_state = self
.state_store
.get_deserialized(&beacon_state_root)?
.ok_or_else(|| {
Error::DBInconsistent(format!("Missing state {}", beacon_state_root))
})?;
let slot = CheckPoint {
beacon_block,
beacon_block_root,
beacon_state,
beacon_state_root,
};
dump.push(slot.clone());
last_slot = slot;
}
Ok(dump)
}
/// Accept some block and attempt to add it to block DAG.
///
/// Will accept blocks from prior slots, however it will reject any block from a future slot.
pub fn process_block<V>(&self, block: BeaconBlock) -> Result<BlockProcessingOutcome, Error> {
debug!("Processing block with slot {}...", block.slot());
let block_root = block.canonical_root();
let present_slot = self.present_slot();
if block.slot > present_slot {
return Ok(BlockProcessingOutcome::InvalidBlock(
InvalidBlock::FutureSlot,
));
}
// Load the blocks parent block from the database, returning invalid if that block is not
// found.
let parent_block_root = block.parent_root;
let parent_block = match self.block_store.get_reader(&parent_block_root)? {
Some(parent_root) => parent_root,
None => {
return Ok(BlockProcessingOutcome::InvalidBlock(
InvalidBlock::ParentUnknown,
));
}
};
// Load the parent blocks state from the database, returning an error if it is not found.
// It is an error because if know the parent block we should also know the parent state.
let parent_state_root = parent_block.state_root();
let parent_state = self
.state_store
.get_reader(&parent_state_root)?
.ok_or(Error::DBInconsistent(format!(
"Missing state {}",
parent_state_root
)))?
.into_beacon_state()
.ok_or(Error::DBInconsistent(format!(
"State SSZ invalid {}",
parent_state_root
)))?;
// TODO: check the block proposer signature BEFORE doing a state transition. This will
// significantly lower exposure surface to DoS attacks.
// Transition the parent state to the present slot.
let mut state = parent_state;
for _ in state.slot..present_slot {
if let Err(e) = state.per_slot_processing(parent_block_root.clone(), &self.spec) {
return Ok(BlockProcessingOutcome::InvalidBlock(
InvalidBlock::SlotProcessingError(e),
));
}
}
// Apply the recieved block to its parent state (which has been transitioned into this
// slot).
if let Err(e) = state.per_block_processing(&block, &self.spec) {
return Ok(BlockProcessingOutcome::InvalidBlock(
InvalidBlock::PerBlockProcessingError(e),
));
}
let state_root = state.canonical_root();
if block.state_root != state_root {
return Ok(BlockProcessingOutcome::InvalidBlock(
InvalidBlock::StateRootMismatch,
));
}
// Store the block and state.
self.block_store.put(&block_root, &ssz_encode(&block)[..])?;
self.state_store.put(&state_root, &ssz_encode(&state)[..])?;
// Update the block DAG.
self.block_graph
.add_leaf(&parent_block_root, block_root.clone());
// If the parent block was the parent_block, automatically update the canonical head.
//
// TODO: this is a first-in-best-dressed scenario that is not ideal; fork_choice should be
// run instead.
if self.head().beacon_block_root == parent_block_root {
self.update_canonical_head(
block.clone(),
block_root.clone(),
state.clone(),
state_root.clone(),
);
// Update the local state variable.
*self.state.write() = state.clone();
}
Ok(BlockProcessingOutcome::ValidBlock(ValidBlock::Processed))
}
/// Produce a new block at the present slot.
///
/// The produced block will not be inheriently valid, it must be signed by a block producer.
/// Block signing is out of the scope of this function and should be done by a separate program.
pub fn produce_block(&self, randao_reveal: Signature) -> Option<(BeaconBlock, BeaconState)> {
debug!("Producing block at slot {}...", self.state.read().slot);
let mut state = self.state.read().clone();
trace!("Finding attestations for new block...");
let attestations = self
.attestation_aggregator
.read()
.get_attestations_for_state(&state, &self.spec);
trace!(
"Inserting {} attestation(s) into new block.",
attestations.len()
);
let parent_root = state
.get_block_root(state.slot.saturating_sub(1), &self.spec)?
.clone();
let mut block = BeaconBlock {
slot: state.slot,
parent_root,
state_root: Hash256::zero(), // Updated after the state is calculated.
randao_reveal: randao_reveal,
eth1_data: Eth1Data {
// TODO: replace with real data
deposit_root: Hash256::zero(),
block_hash: Hash256::zero(),
},
signature: self.spec.empty_signature.clone(), // To be completed by a validator.
body: BeaconBlockBody {
proposer_slashings: vec![],
casper_slashings: vec![],
attestations: attestations,
custody_reseeds: vec![],
custody_challenges: vec![],
custody_responses: vec![],
deposits: vec![],
exits: vec![],
},
};
state
.per_block_processing_without_verifying_block_signature(&block, &self.spec)
.ok()?;
let state_root = state.canonical_root();
block.state_root = state_root;
trace!("Block produced.");
Some((block, state))
}
}
impl From<DBError> for Error {
fn from(e: DBError) -> Error {
Error::DBError(e.message)
}
}
impl From<CommitteesError> for Error {
fn from(e: CommitteesError) -> Error {
Error::CommitteesError(e)
}
}

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@ -1,151 +0,0 @@
use super::{BeaconChain, ClientDB, DBError, SlotClock};
use log::debug;
use ssz::{ssz_encode, Encodable};
use types::{
beacon_state::{BlockProcessingError, SlotProcessingError},
readers::{BeaconBlockReader, BeaconStateReader},
Hash256,
};
#[derive(Debug, PartialEq)]
pub enum ValidBlock {
/// The block was sucessfully processed.
Processed,
}
#[derive(Debug, PartialEq)]
pub enum InvalidBlock {
/// The block slot is greater than the present slot.
FutureSlot,
/// The block state_root does not match the generated state.
StateRootMismatch,
}
#[derive(Debug, PartialEq)]
pub enum Outcome {
/// The block was sucessfully validated.
ValidBlock(ValidBlock),
/// The block was not sucessfully validated.
InvalidBlock(InvalidBlock),
}
#[derive(Debug, PartialEq)]
pub enum Error {
/// There was in internal database error.
DBError(String),
/// The block SSZ encoding is unreadable.
UnableToDecodeBlock,
/// The blocks parent state is not in the database. This is an internal error.
MissingParentState(Hash256),
/// The blocks parent state is in the database, but invalid. This is an internal error.
InvalidParentState(Hash256),
/// The blocks parent state is in the database, but invalid. This is an internal error.
MissingBeaconBlock(Hash256),
/// The parent block is not in the database. The block should not be processed.
InvalidBeaconBlock(Hash256),
/// The parent block is not in the database, but invalid. This is an internal error.
MissingParentBlock(Hash256),
/// There was an error whilst advancing the parent state to the present slot. This is an
/// internal error.
SlotProcessingError(SlotProcessingError),
/// There was an error whilst processing the block against it's state. The block is invalid.
PerBlockProcessingError(BlockProcessingError),
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Accept some block and attempt to add it to block DAG.
///
/// Will accept blocks from prior slots, however it will reject any block from a future slot.
pub fn process_block<V>(&self, block: V) -> Result<Outcome, Error>
where
V: BeaconBlockReader + Encodable + Sized,
{
debug!("Processing block with slot {}...", block.slot());
let block = block
.into_beacon_block()
.ok_or(Error::UnableToDecodeBlock)?;
let block_root = block.canonical_root();
let present_slot = self.present_slot();
if block.slot() > present_slot {
return Ok(Outcome::InvalidBlock(InvalidBlock::FutureSlot));
}
let parent_block_root = block.parent_root();
let parent_block = self
.block_store
.get_reader(&parent_block_root)?
.ok_or(Error::MissingParentBlock(parent_block_root))?;
let parent_state_root = parent_block.state_root();
let parent_state = self
.state_store
.get_reader(&parent_state_root)?
.ok_or(Error::MissingParentState(parent_state_root))?
.into_beacon_state()
.ok_or(Error::InvalidParentState(parent_state_root))?;
let mut state = parent_state;
for _ in state.slot..present_slot {
state.per_slot_processing(parent_block_root.clone(), &self.spec)?;
}
state.per_block_processing(&block, &self.spec)?;
let state_root = state.canonical_root();
if block.state_root != state_root {
return Ok(Outcome::InvalidBlock(InvalidBlock::StateRootMismatch));
}
// Store the block and state.
self.block_store.put(&block_root, &ssz_encode(&block)[..])?;
self.state_store.put(&state_root, &ssz_encode(&state)[..])?;
// Update the block DAG.
self.block_graph
.add_leaf(&parent_block_root, block_root.clone());
// If the parent block was the parent_block, automatically update the canonical head.
//
// TODO: this is a first-in-best-dressed scenario that is not ideal; fork_choice should be
// run instead.
if self.head().beacon_block_root == parent_block_root {
self.update_canonical_head(
block.clone(),
block_root.clone(),
state.clone(),
state_root.clone(),
);
// Update the local state variable.
*self.state.write() = state.clone();
}
Ok(Outcome::ValidBlock(ValidBlock::Processed))
}
}
impl From<DBError> for Error {
fn from(e: DBError) -> Error {
Error::DBError(e.message)
}
}
impl From<SlotProcessingError> for Error {
fn from(e: SlotProcessingError) -> Error {
Error::SlotProcessingError(e)
}
}
impl From<BlockProcessingError> for Error {
fn from(e: BlockProcessingError) -> Error {
Error::PerBlockProcessingError(e)
}
}

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@ -1,102 +0,0 @@
use super::{BeaconChain, ClientDB, DBError, SlotClock};
use bls::Signature;
use log::debug;
use types::{
beacon_state::{BlockProcessingError, SlotProcessingError},
BeaconBlock, BeaconBlockBody, BeaconState, Eth1Data, Hash256,
};
#[derive(Debug, PartialEq)]
pub enum Error {
DBError(String),
SlotProcessingError(SlotProcessingError),
PerBlockProcessingError(BlockProcessingError),
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Produce a new block at the present slot.
///
/// The produced block will not be inheriently valid, it must be signed by a block producer.
/// Block signing is out of the scope of this function and should be done by a separate program.
pub fn produce_block(
&self,
randao_reveal: Signature,
) -> Result<(BeaconBlock, BeaconState), Error> {
debug!("Starting block production...");
let mut state = self.state.read().clone();
debug!("Finding attesatations for new block...");
let attestations = self
.attestation_aggregator
.read()
.get_attestations_for_state(&state, &self.spec);
debug!(
"Inserting {} attestation(s) into new block.",
attestations.len()
);
let parent_root = state
.get_block_root(state.slot.saturating_sub(1), &self.spec)
// TODO: fix unwrap
.unwrap()
.clone();
let mut block = BeaconBlock {
slot: state.slot,
parent_root,
state_root: Hash256::zero(), // Updated after the state is calculated.
randao_reveal: randao_reveal,
eth1_data: Eth1Data {
// TODO: replace with real data
deposit_root: Hash256::zero(),
block_hash: Hash256::zero(),
},
signature: self.spec.empty_signature.clone(), // To be completed by a validator.
body: BeaconBlockBody {
proposer_slashings: vec![],
casper_slashings: vec![],
attestations: attestations,
custody_reseeds: vec![],
custody_challenges: vec![],
custody_responses: vec![],
deposits: vec![],
exits: vec![],
},
};
state.per_block_processing_without_verifying_block_signature(&block, &self.spec)?;
let state_root = state.canonical_root();
block.state_root = state_root;
debug!("Block produced.");
Ok((block, state))
}
}
impl From<DBError> for Error {
fn from(e: DBError) -> Error {
Error::DBError(e.message)
}
}
impl From<SlotProcessingError> for Error {
fn from(e: SlotProcessingError) -> Error {
Error::SlotProcessingError(e)
}
}
impl From<BlockProcessingError> for Error {
fn from(e: BlockProcessingError) -> Error {
Error::PerBlockProcessingError(e)
}
}

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@ -1,47 +0,0 @@
use crate::{BeaconChain, CheckPoint, ClientDB, SlotClock};
use parking_lot::RwLockReadGuard;
use types::{beacon_state::SlotProcessingError, BeaconBlock, BeaconState, Hash256};
#[derive(Debug, PartialEq)]
pub enum Error {
SlotProcessingError(SlotProcessingError),
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Update the canonical head to some new values.
pub fn update_canonical_head(
&self,
new_beacon_block: BeaconBlock,
new_beacon_block_root: Hash256,
new_beacon_state: BeaconState,
new_beacon_state_root: Hash256,
) {
let mut head = self.canonical_head.write();
head.update(
new_beacon_block,
new_beacon_block_root,
new_beacon_state,
new_beacon_state_root,
);
}
/// Returns a read-lock guarded `CheckPoint` struct for reading the head (as chosen by the
/// fork-choice rule).
///
/// 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 recieved, which could be some slots prior to
/// now.
pub fn head(&self) -> RwLockReadGuard<CheckPoint> {
self.canonical_head.read()
}
}
impl From<SlotProcessingError> for Error {
fn from(e: SlotProcessingError) -> Error {
Error::SlotProcessingError(e)
}
}

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@ -1,69 +0,0 @@
use super::{BeaconChain, CheckPoint, ClientDB, DBError, SlotClock};
use types::Hash256;
#[derive(Debug, Clone)]
pub enum Error {
/// There was an error reading from the database. This is an internal error.
DBError(String),
/// There is a missing (or invalid) block in the database. This is an internal error.
MissingBlock(Hash256),
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Dumps the entire canonical chain, from the head to genesis to a vector for analysis.
///
/// This could be a very expensive operation and should only be done in testing/analysis
/// activities.
pub fn chain_dump(&self) -> Result<Vec<CheckPoint>, Error> {
let mut dump = vec![];
let mut last_slot = CheckPoint {
beacon_block: self.head().beacon_block.clone(),
beacon_block_root: self.head().beacon_block_root,
beacon_state: self.head().beacon_state.clone(),
beacon_state_root: self.head().beacon_state_root,
};
dump.push(last_slot.clone());
loop {
let beacon_block_root = last_slot.beacon_block.parent_root;
if beacon_block_root == self.spec.zero_hash {
break; // Genesis has been reached.
}
let beacon_block = self
.block_store
.get_deserialized(&beacon_block_root)?
.ok_or_else(|| Error::MissingBlock(beacon_block_root))?;
let beacon_state_root = beacon_block.state_root;
let beacon_state = self
.state_store
.get_deserialized(&beacon_state_root)?
.ok_or_else(|| Error::MissingBlock(beacon_state_root))?;
let slot = CheckPoint {
beacon_block,
beacon_block_root,
beacon_state,
beacon_state_root,
};
dump.push(slot.clone());
last_slot = slot;
}
Ok(dump)
}
}
impl From<DBError> for Error {
fn from(e: DBError) -> Error {
Error::DBError(e.message)
}
}

View File

@ -1,32 +0,0 @@
use crate::{BeaconChain, CheckPoint, ClientDB, SlotClock};
use parking_lot::RwLockReadGuard;
use types::{BeaconBlock, BeaconState, Hash256};
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Update the justified head to some new values.
pub fn update_finalized_head(
&self,
new_beacon_block: BeaconBlock,
new_beacon_block_root: Hash256,
new_beacon_state: BeaconState,
new_beacon_state_root: Hash256,
) {
let mut finalized_head = self.finalized_head.write();
finalized_head.update(
new_beacon_block,
new_beacon_block_root,
new_beacon_state,
new_beacon_state_root,
);
}
/// Returns a read-lock guarded `CheckPoint` struct for reading the justified head (as chosen,
/// indirectly, by the fork-choice rule).
pub fn finalized_head(&self) -> RwLockReadGuard<CheckPoint> {
self.finalized_head.read()
}
}

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@ -1,100 +0,0 @@
use super::{BeaconChain, ClientDB, SlotClock};
use types::{beacon_state::CommitteesError, PublicKey};
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Returns the the validator index (if any) for the given public key.
///
/// Information is retrieved from the present `beacon_state.validator_registry`.
pub fn validator_index(&self, pubkey: &PublicKey) -> Option<usize> {
for (i, validator) in self
.head()
.beacon_state
.validator_registry
.iter()
.enumerate()
{
if validator.pubkey == *pubkey {
return Some(i);
}
}
None
}
/// Returns the number of slots the validator has been required to propose.
///
/// Returns `None` if the `validator_index` is invalid.
///
/// Information is retrieved from the present `beacon_state.validator_registry`.
pub fn proposer_slots(&self, validator_index: usize) -> Option<u64> {
if let Some(validator) = self.state.read().validator_registry.get(validator_index) {
Some(validator.proposer_slots)
} else {
None
}
}
/// Reads the slot clock, returns `None` 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).
///
/// This is distinct to `present_slot`, which simply reads the latest state. If a
/// call to `read_slot_clock` results in a higher slot than a call to `present_slot`,
/// `self.state` should undergo per slot processing.
pub fn read_slot_clock(&self) -> Option<u64> {
match self.slot_clock.present_slot() {
Ok(some_slot) => some_slot,
_ => None,
}
}
/// Returns slot of the present state.
///
/// This is distinct to `read_slot_clock`, which reads from the actual system clock. If
/// `self.state` has not been transitioned it is possible for the system clock to be on a
/// different slot to what is returned from this call.
pub fn present_slot(&self) -> u64 {
self.state.read().slot
}
/// Returns the block proposer for a given slot.
///
/// Information is read from the present `beacon_state` shuffling, so only information from the
/// present and prior epoch is available.
pub fn block_proposer(&self, slot: u64) -> Result<usize, CommitteesError> {
let index = self
.state
.read()
.get_beacon_proposer_index(slot, &self.spec)?;
Ok(index)
}
/// Returns the justified slot for the present state.
pub fn justified_slot(&self) -> u64 {
self.state.read().justified_slot
}
/// Returns the attestation slot and shard for a given validator index.
///
/// Information is read from the current state, so only information from the present and prior
/// epoch is available.
pub fn validator_attestion_slot_and_shard(
&self,
validator_index: usize,
) -> Result<Option<(u64, u64)>, CommitteesError> {
if let Some((slot, shard, _committee)) = self
.state
.read()
.attestation_slot_and_shard_for_validator(validator_index, &self.spec)?
{
Ok(Some((slot, shard)))
} else {
Ok(None)
}
}
}

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@ -1,129 +1,9 @@
mod attestation_aggregator;
pub mod attestation_processing;
mod attestation_production;
mod attestation_targets;
mod beacon_chain;
mod block_graph;
pub mod block_processing;
pub mod block_production;
mod canonical_head;
mod checkpoint;
pub mod dump;
mod finalized_head;
mod getters;
mod lmd_ghost;
mod state;
use self::attestation_targets::AttestationTargets;
use self::block_graph::BlockGraph;
use attestation_aggregator::AttestationAggregator;
use db::{
stores::{BeaconBlockStore, BeaconStateStore},
ClientDB, DBError,
};
use genesis::{genesis_beacon_block, genesis_beacon_state, GenesisError};
use parking_lot::RwLock;
use slot_clock::SlotClock;
use ssz::ssz_encode;
use std::sync::Arc;
use types::{BeaconState, ChainSpec, Hash256};
pub use self::block_processing::Outcome as BlockProcessingOutcome;
pub use self::beacon_chain::{BeaconChain, Error};
pub use self::checkpoint::CheckPoint;
#[derive(Debug, PartialEq)]
pub enum BeaconChainError {
InsufficientValidators,
GenesisError(GenesisError),
DBError(String),
}
pub struct BeaconChain<T: ClientDB + Sized, U: SlotClock> {
pub block_store: Arc<BeaconBlockStore<T>>,
pub state_store: Arc<BeaconStateStore<T>>,
pub slot_clock: U,
pub block_graph: BlockGraph,
pub attestation_aggregator: RwLock<AttestationAggregator>,
canonical_head: RwLock<CheckPoint>,
finalized_head: RwLock<CheckPoint>,
justified_head: RwLock<CheckPoint>,
pub state: RwLock<BeaconState>,
pub latest_attestation_targets: RwLock<AttestationTargets>,
pub spec: ChainSpec,
}
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Instantiate a new Beacon Chain, from genesis.
pub fn genesis(
state_store: Arc<BeaconStateStore<T>>,
block_store: Arc<BeaconBlockStore<T>>,
slot_clock: U,
spec: ChainSpec,
) -> Result<Self, BeaconChainError> {
if spec.initial_validators.is_empty() {
return Err(BeaconChainError::InsufficientValidators);
}
let genesis_state = genesis_beacon_state(&spec)?;
let state_root = genesis_state.canonical_root();
state_store.put(&state_root, &ssz_encode(&genesis_state)[..])?;
let genesis_block = genesis_beacon_block(state_root, &spec);
let block_root = genesis_block.canonical_root();
block_store.put(&block_root, &ssz_encode(&genesis_block)[..])?;
let block_graph = BlockGraph::new();
block_graph.add_leaf(&Hash256::zero(), block_root.clone());
let finalized_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let justified_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let canonical_head = RwLock::new(CheckPoint::new(
genesis_block.clone(),
block_root.clone(),
genesis_state.clone(),
state_root.clone(),
));
let attestation_aggregator = RwLock::new(AttestationAggregator::new());
let latest_attestation_targets = RwLock::new(AttestationTargets::new());
Ok(Self {
block_store,
state_store,
slot_clock,
block_graph,
attestation_aggregator,
state: RwLock::new(genesis_state.clone()),
justified_head,
finalized_head,
canonical_head,
latest_attestation_targets,
spec: spec,
})
}
}
impl From<DBError> for BeaconChainError {
fn from(e: DBError) -> BeaconChainError {
BeaconChainError::DBError(e.message)
}
}
impl From<GenesisError> for BeaconChainError {
fn from(e: GenesisError) -> BeaconChainError {
BeaconChainError::GenesisError(e)
}
}

View File

@ -1,9 +1,9 @@
use super::{BeaconChain, SlotClock};
use crate::BeaconChain;
use db::{
stores::{BeaconBlockAtSlotError, BeaconBlockStore},
ClientDB, DBError,
};
use slot_clock::TestingSlotClockError;
use slot_clock::{SlotClock, TestingSlotClockError};
use std::collections::HashSet;
use std::sync::Arc;
use types::{

View File

@ -1,29 +0,0 @@
use crate::{BeaconChain, ClientDB, SlotClock};
use types::beacon_state::SlotProcessingError;
impl<T, U> BeaconChain<T, U>
where
T: ClientDB,
U: SlotClock,
{
/// Advance the `self.state` `BeaconState` to the supplied slot.
///
/// This will perform per_slot and per_epoch processing as required.
///
/// The `previous_block_root` will be set to the root of the current head block (as determined
/// by the fork-choice rule).
///
/// It is important to note that this is _not_ the state corresponding to the canonical head
/// block, instead it is that state which may or may not have had additional per slot/epoch
/// processing applied to it.
pub fn advance_state(&self, slot: u64) -> Result<(), SlotProcessingError> {
let state_slot = self.state.read().slot;
let head_block_root = self.head().beacon_block_root;
for _ in state_slot..slot {
self.state
.write()
.per_slot_processing(head_block_root.clone(), &self.spec)?;
}
Ok(())
}
}