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Remove old attestation aggregator

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Paul Hauner 2019-03-30 19:15:15 +11:00
parent 935c64deef
commit 65ae8fda47
No known key found for this signature in database
GPG Key ID: 303E4494BB28068C
2 changed files with 0 additions and 220 deletions
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218
beacon_node/beacon_chain/src/attestation_aggregator.rs
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@ -1,218 +0,0 @@
use ssz::TreeHash;
use state_processing::per_block_processing::validate_attestation_without_signature;
use std::collections::{HashMap, HashSet};
use types::*;
const PHASE_0_CUSTODY_BIT: bool = false;
/// Provides the functionality to:
///
/// - Recieve a `FreeAttestation` and aggregate it into an `Attestation` (or create a new if it
/// doesn't exist).
/// - Store all aggregated or created `Attestation`s.
/// - Produce a list of attestations that would be valid for inclusion in some `BeaconState` (and
/// therefore valid for inclusion in a `BeaconBlock`.
///
/// Note: `Attestations` are stored in memory and never deleted. This is not scalable and must be
/// rectified in a future revision.
#[derive(Default)]
pub struct AttestationAggregator {
store: HashMap<Vec<u8>, Attestation>,
}
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,
/// 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
/// `state.validator_registry`.
BadSignature,
/// The given `slot` does not match the validators committee assignment.
BadSlot,
/// The given `shard` does not match the validators committee assignment, or is not included in
/// a committee for the given slot.
BadShard,
/// Attestation is from the epoch prior to this, ignoring.
TooOld,
}
macro_rules! valid_outcome {
($error: expr) => {
return Ok(Outcome {
valid: true,
message: $error,
});
};
}
macro_rules! invalid_outcome {
($error: expr) => {
return Ok(Outcome {
valid: false,
message: $error,
});
};
}
impl AttestationAggregator {
/// Instantiates a new AttestationAggregator with an empty database.
pub fn new() -> Self {
Self {
store: HashMap::new(),
}
}
/// Accepts some `FreeAttestation`, validates it and either aggregates it upon some existing
/// `Attestation` or produces a new `Attestation`.
///
/// The "validation" provided is not complete, instead the following points are checked:
/// - The given `validator_index` is in the committee for the given `shard` for the given
/// `slot`.
/// - The signature is verified against that of the validator at `validator_index`.
pub fn process_free_attestation(
&mut self,
state: &BeaconState,
free_attestation: &FreeAttestation,
spec: &ChainSpec,
) -> Result<Outcome, BeaconStateError> {
let duties =
match state.get_attestation_duties(free_attestation.validator_index as usize, spec) {
Err(BeaconStateError::EpochCacheUninitialized(e)) => {
panic!("Attempted to access unbuilt cache {:?}.", e)
}
Err(BeaconStateError::EpochOutOfBounds) => invalid_outcome!(Message::TooOld),
Err(BeaconStateError::ShardOutOfBounds) => invalid_outcome!(Message::BadShard),
Err(e) => return Err(e),
Ok(None) => invalid_outcome!(Message::BadValidatorIndex),
Ok(Some(attestation_duties)) => attestation_duties,
};
if free_attestation.data.slot != duties.slot {
invalid_outcome!(Message::BadSlot);
}
if free_attestation.data.shard != duties.shard {
invalid_outcome!(Message::BadShard);
}
let signable_message = AttestationDataAndCustodyBit {
data: free_attestation.data.clone(),
custody_bit: PHASE_0_CUSTODY_BIT,
}
.hash_tree_root();
let validator_record = match state
.validator_registry
.get(free_attestation.validator_index as usize)
{
None => invalid_outcome!(Message::BadValidatorIndex),
Some(validator_record) => validator_record,
};
if !free_attestation.signature.verify(
&signable_message,
spec.get_domain(state.current_epoch(spec), Domain::Attestation, &state.fork),
&validator_record.pubkey,
) {
invalid_outcome!(Message::BadSignature);
}
if let Some(existing_attestation) = self.store.get(&signable_message) {
if let Some(updated_attestation) = aggregate_attestation(
existing_attestation,
&free_attestation.signature,
duties.committee_index as usize,
) {
self.store.insert(signable_message, updated_attestation);
valid_outcome!(Message::Aggregated);
} else {
valid_outcome!(Message::AggregationNotRequired);
}
} else {
let mut aggregate_signature = AggregateSignature::new();
aggregate_signature.add(&free_attestation.signature);
let mut aggregation_bitfield = Bitfield::new();
aggregation_bitfield.set(duties.committee_index as usize, true);
let new_attestation = Attestation {
data: free_attestation.data.clone(),
aggregation_bitfield,
custody_bitfield: Bitfield::new(),
aggregate_signature,
};
self.store.insert(signable_message, new_attestation);
valid_outcome!(Message::NewAttestationCreated);
}
}
/// Returns all known attestations which are:
///
/// - Valid for the given state
/// - Not already in `state.latest_attestations`.
pub fn get_attestations_for_state(
&self,
state: &BeaconState,
spec: &ChainSpec,
) -> Vec<Attestation> {
let mut known_attestation_data: HashSet<AttestationData> = HashSet::new();
state
.previous_epoch_attestations
.iter()
.chain(state.current_epoch_attestations.iter())
.for_each(|attestation| {
known_attestation_data.insert(attestation.data.clone());
});
self.store
.values()
.filter_map(|attestation| {
if validate_attestation_without_signature(&state, attestation, spec).is_ok()
&& !known_attestation_data.contains(&attestation.data)
{
Some(attestation.clone())
} else {
None
}
})
.collect()
}
}
/// Produces a new `Attestation` where:
///
/// - `signature` is added to `Attestation.aggregate_signature`
/// - Attestation.aggregation_bitfield[committee_index]` is set to true.
fn aggregate_attestation(
existing_attestation: &Attestation,
signature: &Signature,
committee_index: usize,
) -> Option<Attestation> {
let already_signed = existing_attestation
.aggregation_bitfield
.get(committee_index)
.unwrap_or(false);
if already_signed {
None
} else {
let mut aggregation_bitfield = existing_attestation.aggregation_bitfield.clone();
aggregation_bitfield.set(committee_index, true);
let mut aggregate_signature = existing_attestation.aggregate_signature.clone();
aggregate_signature.add(&signature);
Some(Attestation {
aggregation_bitfield,
aggregate_signature,
..existing_attestation.clone()
})
}
}

2
beacon_node/beacon_chain/src/lib.rs
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@ -1,4 +1,3 @@
mod attestation_aggregator;
mod beacon_chain; mod beacon_chain;
mod checkpoint; mod checkpoint;
mod errors; mod errors;
@ -8,7 +7,6 @@ pub mod test_utils;
pub use self::beacon_chain::{BeaconChain, BlockProcessingOutcome, InvalidBlock, ValidBlock}; pub use self::beacon_chain::{BeaconChain, BlockProcessingOutcome, InvalidBlock, ValidBlock};
pub use self::checkpoint::CheckPoint; pub use self::checkpoint::CheckPoint;
pub use self::errors::BeaconChainError; pub use self::errors::BeaconChainError;
pub use attestation_aggregator::Outcome as AggregationOutcome;
pub use db; pub use db;
pub use fork_choice; pub use fork_choice;
pub use parking_lot; pub use parking_lot;