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Merge pull request #416 from michaelsproul/op-pool-improvements

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Op Pool: Max Cover and Persistence
This commit is contained in:
Michael Sproul 2019-07-01 17:29:49 +10:00 committed by GitHub
commit 863b2d6fdb
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15 changed files with 893 additions and 164 deletions
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3
beacon_node/beacon_chain/Cargo.toml
View File

@ -26,3 +26,6 @@ state_processing = { path = "../../eth2/state_processing" }
tree_hash = { path = "../../eth2/utils/tree_hash" }
types = { path = "../../eth2/types" }
lmd_ghost = { path = "../../eth2/lmd_ghost" }
[dev-dependencies]
rand = "0.5.5"

10
beacon_node/beacon_chain/src/beacon_chain.rs
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@ -6,7 +6,7 @@ use crate::persisted_beacon_chain::{PersistedBeaconChain, BEACON_CHAIN_DB_KEY};
use lmd_ghost::LmdGhost;
use log::trace;
use operation_pool::DepositInsertStatus;
use operation_pool::OperationPool;
use operation_pool::{OperationPool, PersistedOperationPool};
use parking_lot::{RwLock, RwLockReadGuard};
use slot_clock::SlotClock;
use state_processing::per_block_processing::errors::{
@ -147,11 +147,13 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
let last_finalized_root = p.canonical_head.beacon_state.finalized_root;
let last_finalized_block = &p.canonical_head.beacon_block;
let op_pool = p.op_pool.into_operation_pool(&p.state, &spec);
Ok(Some(BeaconChain {
spec,
slot_clock,
fork_choice: ForkChoice::new(store.clone(), last_finalized_block, last_finalized_root),
op_pool: OperationPool::default(),
op_pool,
canonical_head: RwLock::new(p.canonical_head),
state: RwLock::new(p.state),
genesis_block_root: p.genesis_block_root,
@ -164,6 +166,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
pub fn persist(&self) -> Result<(), Error> {
let p: PersistedBeaconChain<T> = PersistedBeaconChain {
canonical_head: self.canonical_head.read().clone(),
op_pool: PersistedOperationPool::from_operation_pool(&self.op_pool),
genesis_block_root: self.genesis_block_root,
state: self.state.read().clone(),
};
@ -506,8 +509,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
&self,
deposit: Deposit,
) -> Result<DepositInsertStatus, DepositValidationError> {
self.op_pool
.insert_deposit(deposit, &*self.state.read(), &self.spec)
self.op_pool.insert_deposit(deposit)
}
/// Accept some exit and queue it for inclusion in an appropriate block.

3
beacon_node/beacon_chain/src/persisted_beacon_chain.rs
View File

@ -1,4 +1,5 @@
use crate::{BeaconChainTypes, CheckPoint};
use operation_pool::PersistedOperationPool;
use ssz::{Decode, Encode};
use ssz_derive::{Decode, Encode};
use store::{DBColumn, Error as StoreError, StoreItem};
@ -10,7 +11,7 @@ pub const BEACON_CHAIN_DB_KEY: &str = "PERSISTEDBEACONCHAINPERSISTEDBEA";
#[derive(Encode, Decode)]
pub struct PersistedBeaconChain<T: BeaconChainTypes> {
pub canonical_head: CheckPoint<T::EthSpec>,
// TODO: operations pool.
pub op_pool: PersistedOperationPool,
pub genesis_block_root: Hash256,
pub state: BeaconState<T::EthSpec>,
}

6
beacon_node/beacon_chain/src/test_utils.rs
View File

@ -14,6 +14,8 @@ use types::{
Hash256, Keypair, RelativeEpoch, SecretKey, Signature, Slot,
};
pub use crate::persisted_beacon_chain::{PersistedBeaconChain, BEACON_CHAIN_DB_KEY};
/// Indicates how the `BeaconChainHarness` should produce blocks.
#[derive(Clone, Copy, Debug)]
pub enum BlockStrategy {
@ -68,8 +70,8 @@ where
E: EthSpec,
{
pub chain: BeaconChain<CommonTypes<L, E>>,
keypairs: Vec<Keypair>,
spec: ChainSpec,
pub keypairs: Vec<Keypair>,
pub spec: ChainSpec,
}
impl<L, E> BeaconChainHarness<L, E>

52
beacon_node/beacon_chain/tests/tests.rs
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@ -1,16 +1,21 @@
#![cfg(not(debug_assertions))]
use beacon_chain::test_utils::{AttestationStrategy, BeaconChainHarness, BlockStrategy};
use beacon_chain::test_utils::{
AttestationStrategy, BeaconChainHarness, BlockStrategy, CommonTypes, PersistedBeaconChain,
BEACON_CHAIN_DB_KEY,
};
use lmd_ghost::ThreadSafeReducedTree;
use store::MemoryStore;
use types::{EthSpec, MinimalEthSpec, Slot};
use rand::Rng;
use store::{MemoryStore, Store};
use types::test_utils::{SeedableRng, TestRandom, XorShiftRng};
use types::{Deposit, EthSpec, Hash256, MinimalEthSpec, Slot};
// Should ideally be divisible by 3.
pub const VALIDATOR_COUNT: usize = 24;
fn get_harness(
validator_count: usize,
) -> BeaconChainHarness<ThreadSafeReducedTree<MemoryStore, MinimalEthSpec>, MinimalEthSpec> {
type TestForkChoice = ThreadSafeReducedTree<MemoryStore, MinimalEthSpec>;
fn get_harness(validator_count: usize) -> BeaconChainHarness<TestForkChoice, MinimalEthSpec> {
let harness = BeaconChainHarness::new(validator_count);
// Move past the zero slot.
@ -225,3 +230,38 @@ fn does_not_finalize_without_attestation() {
"no epoch should have been finalized"
);
}
#[test]
fn roundtrip_operation_pool() {
let num_blocks_produced = MinimalEthSpec::slots_per_epoch() * 5;
let harness = get_harness(VALIDATOR_COUNT);
// Add some attestations
harness.extend_chain(
num_blocks_produced as usize,
BlockStrategy::OnCanonicalHead,
AttestationStrategy::AllValidators,
);
assert!(harness.chain.op_pool.num_attestations() > 0);
// Add some deposits
let rng = &mut XorShiftRng::from_seed([66; 16]);
for _ in 0..rng.gen_range(1, VALIDATOR_COUNT) {
harness
.chain
.process_deposit(Deposit::random_for_test(rng))
.unwrap();
}
// TODO: could add some other operations
harness.chain.persist().unwrap();
let key = Hash256::from_slice(&BEACON_CHAIN_DB_KEY.as_bytes());
let p: PersistedBeaconChain<CommonTypes<TestForkChoice, MinimalEthSpec>> =
harness.chain.store.get(&key).unwrap().unwrap();
let restored_op_pool = p.op_pool.into_operation_pool(&p.state, &harness.spec);
assert_eq!(harness.chain.op_pool, restored_op_pool);
}

2
eth2/operation_pool/Cargo.toml
View File

@ -5,9 +5,11 @@ authors = ["Michael Sproul <michael@sigmaprime.io>"]
edition = "2018"
[dependencies]
boolean-bitfield = { path = "../utils/boolean-bitfield" }
int_to_bytes = { path = "../utils/int_to_bytes" }
itertools = "0.8"
parking_lot = "0.7"
types = { path = "../types" }
state_processing = { path = "../state_processing" }
ssz = { path = "../utils/ssz" }
ssz_derive = { path = "../utils/ssz_derive" }

91
eth2/operation_pool/src/attestation.rs Normal file
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@ -0,0 +1,91 @@
use crate::max_cover::MaxCover;
use boolean_bitfield::BooleanBitfield;
use types::{Attestation, BeaconState, EthSpec};
pub struct AttMaxCover<'a> {
/// Underlying attestation.
att: &'a Attestation,
/// Bitfield of validators that are covered by this attestation.
fresh_validators: BooleanBitfield,
}
impl<'a> AttMaxCover<'a> {
pub fn new(att: &'a Attestation, fresh_validators: BooleanBitfield) -> Self {
Self {
att,
fresh_validators,
}
}
}
impl<'a> MaxCover for AttMaxCover<'a> {
type Object = Attestation;
type Set = BooleanBitfield;
fn object(&self) -> Attestation {
self.att.clone()
}
fn covering_set(&self) -> &BooleanBitfield {
&self.fresh_validators
}
/// Sneaky: we keep all the attestations together in one bucket, even though
/// their aggregation bitfields refer to different committees. In order to avoid
/// confusing committees when updating covering sets, we update only those attestations
/// whose shard and epoch match the attestation being included in the solution, by the logic
/// that a shard and epoch uniquely identify a committee.
fn update_covering_set(
&mut self,
best_att: &Attestation,
covered_validators: &BooleanBitfield,
) {
if self.att.data.shard == best_att.data.shard
&& self.att.data.target_epoch == best_att.data.target_epoch
{
self.fresh_validators.difference_inplace(covered_validators);
}
}
fn score(&self) -> usize {
self.fresh_validators.num_set_bits()
}
}
/// Extract the validators for which `attestation` would be their earliest in the epoch.
///
/// The reward paid to a proposer for including an attestation is proportional to the number
/// of validators for which the included attestation is their first in the epoch. The attestation
/// is judged against the state's `current_epoch_attestations` or `previous_epoch_attestations`
/// depending on when it was created, and all those validators who have already attested are
/// removed from the `aggregation_bitfield` before returning it.
// TODO: This could be optimised with a map from validator index to whether that validator has
// attested in each of the current and previous epochs. Currently quadratic in number of validators.
pub fn earliest_attestation_validators<T: EthSpec>(
attestation: &Attestation,
state: &BeaconState<T>,
) -> BooleanBitfield {
// Bitfield of validators whose attestations are new/fresh.
let mut new_validators = attestation.aggregation_bitfield.clone();
let state_attestations = if attestation.data.target_epoch == state.current_epoch() {
&state.current_epoch_attestations
} else if attestation.data.target_epoch == state.previous_epoch() {
&state.previous_epoch_attestations
} else {
return BooleanBitfield::from_elem(attestation.aggregation_bitfield.len(), false);
};
state_attestations
.iter()
// In a single epoch, an attester should only be attesting for one shard.
// TODO: we avoid including slashable attestations in the state here,
// but maybe we should do something else with them (like construct slashings).
.filter(|existing_attestation| existing_attestation.data.shard == attestation.data.shard)
.for_each(|existing_attestation| {
// Remove the validators who have signed the existing attestation (they are not new)
new_validators.difference_inplace(&existing_attestation.aggregation_bitfield);
});
new_validators
}

38
eth2/operation_pool/src/attestation_id.rs Normal file
View File

@ -0,0 +1,38 @@
use int_to_bytes::int_to_bytes8;
use ssz::ssz_encode;
use ssz_derive::{Decode, Encode};
use types::{AttestationData, BeaconState, ChainSpec, Domain, Epoch, EthSpec};
/// Serialized `AttestationData` augmented with a domain to encode the fork info.
#[derive(PartialEq, Eq, Clone, Hash, Debug, PartialOrd, Ord, Encode, Decode)]
pub struct AttestationId {
v: Vec<u8>,
}
/// Number of domain bytes that the end of an attestation ID is padded with.
const DOMAIN_BYTES_LEN: usize = 8;
impl AttestationId {
pub fn from_data<T: EthSpec>(
attestation: &AttestationData,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> Self {
let mut bytes = ssz_encode(attestation);
let epoch = attestation.target_epoch;
bytes.extend_from_slice(&AttestationId::compute_domain_bytes(epoch, state, spec));
AttestationId { v: bytes }
}
pub fn compute_domain_bytes<T: EthSpec>(
epoch: Epoch,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> Vec<u8> {
int_to_bytes8(spec.get_domain(epoch, Domain::Attestation, &state.fork))
}
pub fn domain_bytes_match(&self, domain_bytes: &[u8]) -> bool {
&self.v[self.v.len() - DOMAIN_BYTES_LEN..] == domain_bytes
}
}

196
eth2/operation_pool/src/lib.rs
View File

@ -1,13 +1,19 @@
use int_to_bytes::int_to_bytes8;
mod attestation;
mod attestation_id;
mod max_cover;
mod persistence;
pub use persistence::PersistedOperationPool;
use attestation::{earliest_attestation_validators, AttMaxCover};
use attestation_id::AttestationId;
use itertools::Itertools;
use max_cover::maximum_cover;
use parking_lot::RwLock;
use ssz::ssz_encode;
use state_processing::per_block_processing::errors::{
AttestationValidationError, AttesterSlashingValidationError, DepositValidationError,
ExitValidationError, ProposerSlashingValidationError, TransferValidationError,
};
#[cfg(not(test))]
use state_processing::per_block_processing::verify_deposit_merkle_proof;
use state_processing::per_block_processing::{
get_slashable_indices_modular, validate_attestation,
validate_attestation_time_independent_only, verify_attester_slashing, verify_exit,
@ -16,13 +22,12 @@ use state_processing::per_block_processing::{
};
use std::collections::{btree_map::Entry, hash_map, BTreeMap, HashMap, HashSet};
use std::marker::PhantomData;
use types::chain_spec::Domain;
use types::{
Attestation, AttestationData, AttesterSlashing, BeaconState, ChainSpec, Deposit, Epoch,
EthSpec, ProposerSlashing, Transfer, Validator, VoluntaryExit,
Attestation, AttesterSlashing, BeaconState, ChainSpec, Deposit, EthSpec, ProposerSlashing,
Transfer, Validator, VoluntaryExit,
};
#[derive(Default)]
#[derive(Default, Debug)]
pub struct OperationPool<T: EthSpec + Default> {
/// Map from attestation ID (see below) to vectors of attestations.
attestations: RwLock<HashMap<AttestationId, Vec<Attestation>>>,
@ -43,71 +48,6 @@ pub struct OperationPool<T: EthSpec + Default> {
_phantom: PhantomData<T>,
}
/// Serialized `AttestationData` augmented with a domain to encode the fork info.
#[derive(PartialEq, Eq, Clone, Hash, Debug)]
struct AttestationId(Vec<u8>);
/// Number of domain bytes that the end of an attestation ID is padded with.
const DOMAIN_BYTES_LEN: usize = 8;
impl AttestationId {
fn from_data<T: EthSpec>(
attestation: &AttestationData,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> Self {
let mut bytes = ssz_encode(attestation);
let epoch = attestation.target_epoch;
bytes.extend_from_slice(&AttestationId::compute_domain_bytes(epoch, state, spec));
AttestationId(bytes)
}
fn compute_domain_bytes<T: EthSpec>(
epoch: Epoch,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> Vec<u8> {
int_to_bytes8(spec.get_domain(epoch, Domain::Attestation, &state.fork))
}
fn domain_bytes_match(&self, domain_bytes: &[u8]) -> bool {
&self.0[self.0.len() - DOMAIN_BYTES_LEN..] == domain_bytes
}
}
/// Compute a fitness score for an attestation.
///
/// The score is calculated by determining the number of *new* attestations that
/// the aggregate attestation introduces, and is proportional to the size of the reward we will
/// receive for including it in a block.
// TODO: this could be optimised with a map from validator index to whether that validator has
// attested in each of the current and previous epochs. Currently quadractic in number of validators.
fn attestation_score<T: EthSpec>(attestation: &Attestation, state: &BeaconState<T>) -> usize {
// Bitfield of validators whose attestations are new/fresh.
let mut new_validators = attestation.aggregation_bitfield.clone();
let state_attestations = if attestation.data.target_epoch == state.current_epoch() {
&state.current_epoch_attestations
} else if attestation.data.target_epoch == state.previous_epoch() {
&state.previous_epoch_attestations
} else {
return 0;
};
state_attestations
.iter()
// In a single epoch, an attester should only be attesting for one shard.
// TODO: we avoid including slashable attestations in the state here,
// but maybe we should do something else with them (like construct slashings).
.filter(|current_attestation| current_attestation.data.shard == attestation.data.shard)
.for_each(|current_attestation| {
// Remove the validators who have signed the existing attestation (they are not new)
new_validators.difference_inplace(&current_attestation.aggregation_bitfield);
});
new_validators.num_set_bits()
}
#[derive(Debug, PartialEq, Clone)]
pub enum DepositInsertStatus {
/// The deposit was not already in the pool.
@ -176,29 +116,19 @@ impl<T: EthSpec> OperationPool<T> {
let current_epoch = state.current_epoch();
let prev_domain_bytes = AttestationId::compute_domain_bytes(prev_epoch, state, spec);
let curr_domain_bytes = AttestationId::compute_domain_bytes(current_epoch, state, spec);
self.attestations
.read()
let reader = self.attestations.read();
let valid_attestations = reader
.iter()
.filter(|(key, _)| {
key.domain_bytes_match(&prev_domain_bytes)
|| key.domain_bytes_match(&curr_domain_bytes)
})
.flat_map(|(_, attestations)| attestations)
// That are not superseded by an attestation included in the state...
.filter(|attestation| !superior_attestation_exists_in_state(state, attestation))
// That are valid...
.filter(|attestation| validate_attestation(state, attestation, spec).is_ok())
// Scored by the number of new attestations they introduce (descending)
// TODO: need to consider attestations introduced in THIS block
.map(|att| (att, attestation_score(att, state)))
// Don't include any useless attestations (score 0)
.filter(|&(_, score)| score != 0)
.sorted_by_key(|&(_, score)| std::cmp::Reverse(score))
// Limited to the maximum number of attestations per block
.take(spec.max_attestations as usize)
.map(|(att, _)| att)
.cloned()
.collect()
.map(|att| AttMaxCover::new(att, earliest_attestation_validators(att, state)));
maximum_cover(valid_attestations, spec.max_attestations as usize)
}
/// Remove attestations which are too old to be included in a block.
@ -219,20 +149,14 @@ impl<T: EthSpec> OperationPool<T> {
/// Add a deposit to the pool.
///
/// No two distinct deposits should be added with the same index.
#[cfg_attr(test, allow(unused_variables))]
pub fn insert_deposit(
&self,
deposit: Deposit,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> Result<DepositInsertStatus, DepositValidationError> {
use DepositInsertStatus::*;
match self.deposits.write().entry(deposit.index) {
Entry::Vacant(entry) => {
// TODO: fix tests to generate valid merkle proofs
#[cfg(not(test))]
verify_deposit_merkle_proof(state, &deposit, spec)?;
entry.insert(deposit);
Ok(Fresh)
}
@ -240,9 +164,6 @@ impl<T: EthSpec> OperationPool<T> {
if entry.get() == &deposit {
Ok(Duplicate)
} else {
// TODO: fix tests to generate valid merkle proofs
#[cfg(not(test))]
verify_deposit_merkle_proof(state, &deposit, spec)?;
Ok(Replaced(Box::new(entry.insert(deposit))))
}
}
@ -253,7 +174,9 @@ impl<T: EthSpec> OperationPool<T> {
///
/// Take at most the maximum number of deposits, beginning from the current deposit index.
pub fn get_deposits(&self, state: &BeaconState<T>, spec: &ChainSpec) -> Vec<Deposit> {
// TODO: might want to re-check the Merkle proof to account for Eth1 forking
// TODO: We need to update the Merkle proofs for existing deposits as more deposits
// are added. It probably makes sense to construct the proofs from scratch when forming
// a block, using fresh info from the ETH1 chain for the current deposit root.
let start_idx = state.deposit_index;
(start_idx..start_idx + spec.max_deposits)
.map(|idx| self.deposits.read().get(&idx).cloned())
@ -484,34 +407,6 @@ impl<T: EthSpec> OperationPool<T> {
}
}
/// Returns `true` if the state already contains a `PendingAttestation` that is superior to the
/// given `attestation`.
///
/// A validator has nothing to gain from re-including an attestation and it adds load to the
/// network.
///
/// An existing `PendingAttestation` is superior to an existing `attestation` if:
///
/// - Their `AttestationData` is equal.
/// - `attestation` does not contain any signatures that `PendingAttestation` does not have.
fn superior_attestation_exists_in_state<T: EthSpec>(
state: &BeaconState<T>,
attestation: &Attestation,
) -> bool {
state
.current_epoch_attestations
.iter()
.chain(state.previous_epoch_attestations.iter())
.any(|existing_attestation| {
let bitfield = &attestation.aggregation_bitfield;
let existing_bitfield = &existing_attestation.aggregation_bitfield;
existing_attestation.data == attestation.data
&& bitfield.intersection(existing_bitfield).num_set_bits()
== bitfield.num_set_bits()
})
}
/// Filter up to a maximum number of operations out of an iterator.
fn filter_limit_operations<'a, T: 'a, I, F>(operations: I, filter: F, limit: u64) -> Vec<T>
where
@ -547,6 +442,18 @@ fn prune_validator_hash_map<T, F, E: EthSpec>(
});
}
/// Compare two operation pools.
impl<T: EthSpec + Default> PartialEq for OperationPool<T> {
fn eq(&self, other: &Self) -> bool {
*self.attestations.read() == *other.attestations.read()
&& *self.deposits.read() == *other.deposits.read()
&& *self.attester_slashings.read() == *other.attester_slashings.read()
&& *self.proposer_slashings.read() == *other.proposer_slashings.read()
&& *self.voluntary_exits.read() == *other.voluntary_exits.read()
&& *self.transfers.read() == *other.transfers.read()
}
}
#[cfg(test)]
mod tests {
use super::DepositInsertStatus::*;
@ -557,22 +464,15 @@ mod tests {
#[test]
fn insert_deposit() {
let rng = &mut XorShiftRng::from_seed([42; 16]);
let (ref spec, ref state) = test_state(rng);
let op_pool = OperationPool::new();
let op_pool = OperationPool::<MinimalEthSpec>::new();
let deposit1 = make_deposit(rng);
let mut deposit2 = make_deposit(rng);
deposit2.index = deposit1.index;
assert_eq!(op_pool.insert_deposit(deposit1.clone()), Ok(Fresh));
assert_eq!(op_pool.insert_deposit(deposit1.clone()), Ok(Duplicate));
assert_eq!(
op_pool.insert_deposit(deposit1.clone(), state, spec),
Ok(Fresh)
);
assert_eq!(
op_pool.insert_deposit(deposit1.clone(), state, spec),
Ok(Duplicate)
);
assert_eq!(
op_pool.insert_deposit(deposit2, state, spec),
op_pool.insert_deposit(deposit2),
Ok(Replaced(Box::new(deposit1)))
);
}
@ -591,10 +491,7 @@ mod tests {
let deposits = dummy_deposits(rng, start, max_deposits + extra);
for deposit in &deposits {
assert_eq!(
op_pool.insert_deposit(deposit.clone(), &state, &spec),
Ok(Fresh)
);
assert_eq!(op_pool.insert_deposit(deposit.clone()), Ok(Fresh));
}
state.deposit_index = start + offset;
@ -610,8 +507,7 @@ mod tests {
#[test]
fn prune_deposits() {
let rng = &mut XorShiftRng::from_seed([42; 16]);
let (spec, state) = test_state(rng);
let op_pool = OperationPool::new();
let op_pool = OperationPool::<MinimalEthSpec>::new();
let start1 = 100;
// test is super slow in debug mode if this parameter is too high
@ -623,7 +519,7 @@ mod tests {
let deposits2 = dummy_deposits(rng, start2, count);
for d in deposits1.into_iter().chain(deposits2) {
assert!(op_pool.insert_deposit(d, &state, &spec).is_ok());
assert!(op_pool.insert_deposit(d).is_ok());
}
assert_eq!(op_pool.num_deposits(), 2 * count as usize);
@ -734,15 +630,13 @@ mod tests {
state_builder.teleport_to_slot(slot);
state_builder.build_caches(&spec).unwrap();
let (state, keypairs) = state_builder.build();
(state, keypairs, MainnetEthSpec::default_spec())
}
#[test]
fn test_attestation_score() {
fn test_earliest_attestation() {
let (ref mut state, ref keypairs, ref spec) =
attestation_test_state::<MainnetEthSpec>(1);
let slot = state.slot - 1;
let committees = state
.get_crosslink_committees_at_slot(slot)
@ -775,9 +669,8 @@ mod tests {
assert_eq!(
att1.aggregation_bitfield.num_set_bits(),
attestation_score(&att1, state)
earliest_attestation_validators(&att1, state).num_set_bits()
);
state.current_epoch_attestations.push(PendingAttestation {
aggregation_bitfield: att1.aggregation_bitfield.clone(),
data: att1.data.clone(),
@ -785,7 +678,10 @@ mod tests {
proposer_index: 0,
});
assert_eq!(cc.committee.len() - 2, attestation_score(&att2, state));
assert_eq!(
cc.committee.len() - 2,
earliest_attestation_validators(&att2, state).num_set_bits()
);
}
}

189
eth2/operation_pool/src/max_cover.rs Normal file
View File

@ -0,0 +1,189 @@
/// Trait for types that we can compute a maximum cover for.
///
/// Terminology:
/// * `item`: something that implements this trait
/// * `element`: something contained in a set, and covered by the covering set of an item
/// * `object`: something extracted from an item in order to comprise a solution
/// See: https://en.wikipedia.org/wiki/Maximum_coverage_problem
pub trait MaxCover {
/// The result type, of which we would eventually like a collection of maximal quality.
type Object;
/// The type used to represent sets.
type Set: Clone;
/// Extract an object for inclusion in a solution.
fn object(&self) -> Self::Object;
/// Get the set of elements covered.
fn covering_set(&self) -> &Self::Set;
/// Update the set of items covered, for the inclusion of some object in the solution.
fn update_covering_set(&mut self, max_obj: &Self::Object, max_set: &Self::Set);
/// The quality of this item's covering set, usually its cardinality.
fn score(&self) -> usize;
}
/// Helper struct to track which items of the input are still available for inclusion.
/// Saves removing elements from the work vector.
struct MaxCoverItem<T> {
item: T,
available: bool,
}
impl<T> MaxCoverItem<T> {
fn new(item: T) -> Self {
MaxCoverItem {
item,
available: true,
}
}
}
/// Compute an approximate maximum cover using a greedy algorithm.
///
/// * Time complexity: `O(limit * items_iter.len())`
/// * Space complexity: `O(item_iter.len())`
pub fn maximum_cover<'a, I, T>(items_iter: I, limit: usize) -> Vec<T::Object>
where
I: IntoIterator<Item = T>,
T: MaxCover,
{
// Construct an initial vec of all items, marked available.
let mut all_items: Vec<_> = items_iter
.into_iter()
.map(MaxCoverItem::new)
.filter(|x| x.item.score() != 0)
.collect();
let mut result = vec![];
for _ in 0..limit {
// Select the item with the maximum score.
let (best_item, best_cover) = match all_items
.iter_mut()
.filter(|x| x.available && x.item.score() != 0)
.max_by_key(|x| x.item.score())
{
Some(x) => {
x.available = false;
(x.item.object(), x.item.covering_set().clone())
}
None => return result,
};
// Update the covering sets of the other items, for the inclusion of the selected item.
// Items covered by the selected item can't be re-covered.
all_items
.iter_mut()
.filter(|x| x.available && x.item.score() != 0)
.for_each(|x| x.item.update_covering_set(&best_item, &best_cover));
result.push(best_item);
}
result
}
#[cfg(test)]
mod test {
use super::*;
use std::iter::FromIterator;
use std::{collections::HashSet, hash::Hash};
impl<T> MaxCover for HashSet<T>
where
T: Clone + Eq + Hash,
{
type Object = Self;
type Set = Self;
fn object(&self) -> Self {
self.clone()
}
fn covering_set(&self) -> &Self {
&self
}
fn update_covering_set(&mut self, _: &Self, other: &Self) {
let mut difference = &*self - other;
std::mem::swap(self, &mut difference);
}
fn score(&self) -> usize {
self.len()
}
}
fn example_system() -> Vec<HashSet<usize>> {
vec![
HashSet::from_iter(vec![3]),
HashSet::from_iter(vec![1, 2, 4, 5]),
HashSet::from_iter(vec![1, 2, 4, 5]),
HashSet::from_iter(vec![1]),
HashSet::from_iter(vec![2, 4, 5]),
]
}
#[test]
fn zero_limit() {
let cover = maximum_cover(example_system(), 0);
assert_eq!(cover.len(), 0);
}
#[test]
fn one_limit() {
let sets = example_system();
let cover = maximum_cover(sets.clone(), 1);
assert_eq!(cover.len(), 1);
assert_eq!(cover[0], sets[1]);
}
// Check that even if the limit provides room, we don't include useless items in the soln.
#[test]
fn exclude_zero_score() {
let sets = example_system();
for k in 2..10 {
let cover = maximum_cover(sets.clone(), k);
assert_eq!(cover.len(), 2);
assert_eq!(cover[0], sets[1]);
assert_eq!(cover[1], sets[0]);
}
}
fn quality<T: Eq + Hash>(solution: &[HashSet<T>]) -> usize {
solution.iter().map(HashSet::len).sum()
}
// Optimal solution is the first three sets (quality 15) but our greedy algorithm
// will select the last three (quality 11). The comment at the end of each line
// shows that set's score at each iteration, with a * indicating that it will be chosen.
#[test]
fn suboptimal() {
let sets = vec![
HashSet::from_iter(vec![0, 1, 8, 11, 14]), // 5, 3, 2
HashSet::from_iter(vec![2, 3, 7, 9, 10]), // 5, 3, 2
HashSet::from_iter(vec![4, 5, 6, 12, 13]), // 5, 4, 2
HashSet::from_iter(vec![9, 10]), // 4, 4, 2*
HashSet::from_iter(vec![5, 6, 7, 8]), // 4, 4*
HashSet::from_iter(vec![0, 1, 2, 3, 4]), // 5*
];
let cover = maximum_cover(sets.clone(), 3);
assert_eq!(quality(&cover), 11);
}
#[test]
fn intersecting_ok() {
let sets = vec![
HashSet::from_iter(vec![1, 2, 3, 4, 5, 6, 7, 8]),
HashSet::from_iter(vec![1, 2, 3, 9, 10, 11]),
HashSet::from_iter(vec![4, 5, 6, 12, 13, 14]),
HashSet::from_iter(vec![7, 8, 15, 16, 17, 18]),
HashSet::from_iter(vec![1, 2, 9, 10]),
HashSet::from_iter(vec![1, 5, 6, 8]),
HashSet::from_iter(vec![1, 7, 11, 19]),
];
let cover = maximum_cover(sets.clone(), 5);
assert_eq!(quality(&cover), 19);
assert_eq!(cover.len(), 5);
}
}

121
eth2/operation_pool/src/persistence.rs Normal file
View File

@ -0,0 +1,121 @@
use crate::attestation_id::AttestationId;
use crate::OperationPool;
use parking_lot::RwLock;
use ssz_derive::{Decode, Encode};
use types::*;
/// SSZ-serializable version of `OperationPool`.
///
/// Operations are stored in arbitrary order, so it's not a good idea to compare instances
/// of this type (or its encoded form) for equality. Convert back to an `OperationPool` first.
#[derive(Encode, Decode)]
pub struct PersistedOperationPool {
/// Mapping from attestation ID to attestation mappings.
// We could save space by not storing the attestation ID, but it might
// be difficult to make that roundtrip due to eager aggregation.
attestations: Vec<(AttestationId, Vec<Attestation>)>,
deposits: Vec<Deposit>,
/// Attester slashings.
attester_slashings: Vec<AttesterSlashing>,
/// Proposer slashings.
proposer_slashings: Vec<ProposerSlashing>,
/// Voluntary exits.
voluntary_exits: Vec<VoluntaryExit>,
/// Transfers.
transfers: Vec<Transfer>,
}
impl PersistedOperationPool {
/// Convert an `OperationPool` into serializable form.
pub fn from_operation_pool<T: EthSpec>(operation_pool: &OperationPool<T>) -> Self {
let attestations = operation_pool
.attestations
.read()
.iter()
.map(|(att_id, att)| (att_id.clone(), att.clone()))
.collect();
let deposits = operation_pool
.deposits
.read()
.iter()
.map(|(_, d)| d.clone())
.collect();
let attester_slashings = operation_pool
.attester_slashings
.read()
.iter()
.map(|(_, slashing)| slashing.clone())
.collect();
let proposer_slashings = operation_pool
.proposer_slashings
.read()
.iter()
.map(|(_, slashing)| slashing.clone())
.collect();
let voluntary_exits = operation_pool
.voluntary_exits
.read()
.iter()
.map(|(_, exit)| exit.clone())
.collect();
let transfers = operation_pool.transfers.read().iter().cloned().collect();
Self {
attestations,
deposits,
attester_slashings,
proposer_slashings,
voluntary_exits,
transfers,
}
}
/// Reconstruct an `OperationPool`.
pub fn into_operation_pool<T: EthSpec>(
self,
state: &BeaconState<T>,
spec: &ChainSpec,
) -> OperationPool<T> {
let attestations = RwLock::new(self.attestations.into_iter().collect());
let deposits = RwLock::new(self.deposits.into_iter().map(|d| (d.index, d)).collect());
let attester_slashings = RwLock::new(
self.attester_slashings
.into_iter()
.map(|slashing| {
(
OperationPool::attester_slashing_id(&slashing, state, spec),
slashing,
)
})
.collect(),
);
let proposer_slashings = RwLock::new(
self.proposer_slashings
.into_iter()
.map(|slashing| (slashing.proposer_index, slashing))
.collect(),
);
let voluntary_exits = RwLock::new(
self.voluntary_exits
.into_iter()
.map(|exit| (exit.validator_index, exit))
.collect(),
);
let transfers = RwLock::new(self.transfers.into_iter().collect());
OperationPool {
attestations,
deposits,
attester_slashings,
proposer_slashings,
voluntary_exits,
transfers,
_phantom: Default::default(),
}
}
}

3
eth2/utils/boolean-bitfield/src/lib.rs
View File

@ -13,7 +13,7 @@ use std::default;
/// A BooleanBitfield represents a set of booleans compactly stored as a vector of bits.
/// The BooleanBitfield is given a fixed size during construction. Reads outside of the current size return an out-of-bounds error. Writes outside of the current size expand the size of the set.
#[derive(Debug, Clone)]
#[derive(Debug, Clone, Hash)]
pub struct BooleanBitfield(BitVec);
/// Error represents some reason a request against a bitfield was not satisfied
@ -170,6 +170,7 @@ impl cmp::PartialEq for BooleanBitfield {
ssz::ssz_encode(self) == ssz::ssz_encode(other)
}
}
impl Eq for BooleanBitfield {}
/// Create a new bitfield that is a union of two other bitfields.
///

158
eth2/utils/ssz/src/decode/impls.rs
View File

@ -41,6 +41,153 @@ impl_decodable_for_uint!(usize, 32);
#[cfg(target_pointer_width = "64")]
impl_decodable_for_uint!(usize, 64);
macro_rules! impl_decode_for_tuples {
($(
$Tuple:ident {
$(($idx:tt) -> $T:ident)+
}
)+) => {
$(
impl<$($T: Decode),+> Decode for ($($T,)+) {
fn is_ssz_fixed_len() -> bool {
$(
<$T as Decode>::is_ssz_fixed_len() &&
)*
true
}
fn ssz_fixed_len() -> usize {
if <Self as Decode>::is_ssz_fixed_len() {
$(
<$T as Decode>::ssz_fixed_len() +
)*
0
} else {
BYTES_PER_LENGTH_OFFSET
}
}
fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
let mut builder = SszDecoderBuilder::new(bytes);
$(
builder.register_type::<$T>()?;
)*
let mut decoder = builder.build()?;
Ok(($(
decoder.decode_next::<$T>()?,
)*
))
}
}
)+
}
}
impl_decode_for_tuples! {
Tuple2 {
(0) -> A
(1) -> B
}
Tuple3 {
(0) -> A
(1) -> B
(2) -> C
}
Tuple4 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
}
Tuple5 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
}
Tuple6 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
}
Tuple7 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
}
Tuple8 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
}
Tuple9 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
}
Tuple10 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
}
Tuple11 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
(10) -> K
}
Tuple12 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
(10) -> K
(11) -> L
}
}
impl Decode for bool {
fn is_ssz_fixed_len() -> bool {
true
@ -520,4 +667,15 @@ mod tests {
})
);
}
#[test]
fn tuple() {
assert_eq!(<(u16, u16)>::from_ssz_bytes(&[0, 0, 0, 0]), Ok((0, 0)));
assert_eq!(<(u16, u16)>::from_ssz_bytes(&[16, 0, 17, 0]), Ok((16, 17)));
assert_eq!(<(u16, u16)>::from_ssz_bytes(&[0, 1, 2, 0]), Ok((256, 2)));
assert_eq!(
<(u16, u16)>::from_ssz_bytes(&[255, 255, 0, 0]),
Ok((65535, 0))
);
}
}

155
eth2/utils/ssz/src/encode/impls.rs
View File

@ -31,6 +31,154 @@ impl_encodable_for_uint!(usize, 32);
#[cfg(target_pointer_width = "64")]
impl_encodable_for_uint!(usize, 64);
// Based on the `tuple_impls` macro from the standard library.
macro_rules! impl_encode_for_tuples {
($(
$Tuple:ident {
$(($idx:tt) -> $T:ident)+
}
)+) => {
$(
impl<$($T: Encode),+> Encode for ($($T,)+) {
fn is_ssz_fixed_len() -> bool {
$(
<$T as Encode>::is_ssz_fixed_len() &&
)*
true
}
fn ssz_fixed_len() -> usize {
if <Self as Encode>::is_ssz_fixed_len() {
$(
<$T as Encode>::ssz_fixed_len() +
)*
0
} else {
BYTES_PER_LENGTH_OFFSET
}
}
fn ssz_append(&self, buf: &mut Vec<u8>) {
let offset = $(
<$T as Encode>::ssz_fixed_len() +
)*
0;
let mut encoder = SszEncoder::container(buf, offset);
$(
encoder.append(&self.$idx);
)*
encoder.finalize();
}
}
)+
}
}
impl_encode_for_tuples! {
Tuple2 {
(0) -> A
(1) -> B
}
Tuple3 {
(0) -> A
(1) -> B
(2) -> C
}
Tuple4 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
}
Tuple5 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
}
Tuple6 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
}
Tuple7 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
}
Tuple8 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
}
Tuple9 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
}
Tuple10 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
}
Tuple11 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
(10) -> K
}
Tuple12 {
(0) -> A
(1) -> B
(2) -> C
(3) -> D
(4) -> E
(5) -> F
(6) -> G
(7) -> H
(8) -> I
(9) -> J
(10) -> K
(11) -> L
}
}
/// The SSZ "union" type.
impl<T: Encode> Encode for Option<T> {
fn is_ssz_fixed_len() -> bool {
@ -292,4 +440,11 @@ mod tests {
assert_eq!([1, 0, 0, 0].as_ssz_bytes(), vec![1, 0, 0, 0]);
assert_eq!([1, 2, 3, 4].as_ssz_bytes(), vec![1, 2, 3, 4]);
}
#[test]
fn tuple() {
assert_eq!((10u8, 11u8).as_ssz_bytes(), vec![10, 11]);
assert_eq!((10u32, 11u8).as_ssz_bytes(), vec![10, 0, 0, 0, 11]);
assert_eq!((10u8, 11u8, 12u8).as_ssz_bytes(), vec![10, 11, 12]);
}
}

30
eth2/utils/ssz/tests/tests.rs
View File

@ -346,4 +346,34 @@ mod round_trip {
round_trip(vec);
}
#[test]
fn tuple_u8_u16() {
let vec: Vec<(u8, u16)> = vec![
(0, 0),
(0, 1),
(1, 0),
(u8::max_value(), u16::max_value()),
(0, u16::max_value()),
(u8::max_value(), 0),
(42, 12301),
];
round_trip(vec);
}
#[test]
fn tuple_vec_vec() {
let vec: Vec<(u64, Vec<u8>, Vec<Vec<u16>>)> = vec![
(0, vec![], vec![vec![]]),
(99, vec![101], vec![vec![], vec![]]),
(
42,
vec![12, 13, 14],
vec![vec![99, 98, 97, 96], vec![42, 44, 46, 48, 50]],
),
];
round_trip(vec);
}
}