lighthouse/eth2/lmd_ghost/tests/test.rs
Michael Sproul bd1b61a5b1 Forwards block root iterators (#672)
* Implement forwards block root iterators

* Clean up errors and docs
2019-12-06 18:52:11 +11:00

400 lines
13 KiB
Rust

#![cfg(not(debug_assertions))]
#[macro_use]
extern crate lazy_static;
use beacon_chain::test_utils::{
generate_deterministic_keypairs, AttestationStrategy,
BeaconChainHarness as BaseBeaconChainHarness, BlockStrategy, HarnessType,
};
use lmd_ghost::{LmdGhost, ThreadSafeReducedTree as BaseThreadSafeReducedTree};
use rand::{prelude::*, rngs::StdRng};
use std::sync::Arc;
use store::{iter::AncestorIter, MemoryStore, Store};
use types::{BeaconBlock, EthSpec, Hash256, MinimalEthSpec, Slot};
// Should ideally be divisible by 3.
pub const VALIDATOR_COUNT: usize = 3 * 8;
type TestEthSpec = MinimalEthSpec;
type ThreadSafeReducedTree = BaseThreadSafeReducedTree<MemoryStore<TestEthSpec>, TestEthSpec>;
type BeaconChainHarness = BaseBeaconChainHarness<HarnessType<TestEthSpec>>;
type RootAndSlot = (Hash256, Slot);
lazy_static! {
/// A lazy-static instance of a `BeaconChainHarness` that contains two forks.
///
/// Reduces test setup time by providing a common harness.
static ref FORKED_HARNESS: ForkedHarness = ForkedHarness::new();
}
/// Contains a `BeaconChainHarness` that has two forks, caused by a validator skipping a slot and
/// then some validators building on one head and some on the other.
///
/// Care should be taken to ensure that the `ForkedHarness` does not expose any interior mutability
/// from it's fields. This would cause cross-contamination between tests when used with
/// `lazy_static`.
struct ForkedHarness {
/// Private (not `pub`) because the `BeaconChainHarness` has interior mutability. We
/// don't expose it to avoid contamination between tests.
harness: BeaconChainHarness,
pub genesis_block_root: Hash256,
pub genesis_block: BeaconBlock<TestEthSpec>,
pub honest_head: RootAndSlot,
pub faulty_head: RootAndSlot,
/// Honest roots in reverse order (slot high to low)
pub honest_roots: Vec<RootAndSlot>,
/// Faulty roots in reverse order (slot high to low)
pub faulty_roots: Vec<RootAndSlot>,
}
impl ForkedHarness {
/// A new standard instance of with constant parameters.
pub fn new() -> Self {
let harness = BeaconChainHarness::new(
MinimalEthSpec,
generate_deterministic_keypairs(VALIDATOR_COUNT),
);
// Move past the zero slot.
harness.advance_slot();
let delay = TestEthSpec::default_spec().min_attestation_inclusion_delay as usize;
let initial_blocks = delay + 5;
// Build an initial chain where all validators agree.
harness.extend_chain(
initial_blocks,
BlockStrategy::OnCanonicalHead,
AttestationStrategy::AllValidators,
);
let two_thirds = (VALIDATOR_COUNT / 3) * 2;
let honest_validators: Vec<usize> = (0..two_thirds).collect();
let faulty_validators: Vec<usize> = (two_thirds..VALIDATOR_COUNT).collect();
let honest_fork_blocks = delay + 5;
let faulty_fork_blocks = delay + 5;
let (honest_head, faulty_head) = harness.generate_two_forks_by_skipping_a_block(
&honest_validators,
&faulty_validators,
honest_fork_blocks,
faulty_fork_blocks,
);
let mut honest_roots = get_ancestor_roots(harness.chain.store.clone(), honest_head);
honest_roots.insert(
0,
(honest_head, get_slot_for_block_root(&harness, honest_head)),
);
let mut faulty_roots = get_ancestor_roots(harness.chain.store.clone(), faulty_head);
faulty_roots.insert(
0,
(faulty_head, get_slot_for_block_root(&harness, faulty_head)),
);
let genesis_block_root = harness.chain.genesis_block_root;
let genesis_block = harness
.chain
.store
.get::<BeaconBlock<TestEthSpec>>(&genesis_block_root)
.expect("Genesis block should exist")
.expect("DB should not error");
Self {
harness,
genesis_block_root,
genesis_block,
honest_head: *honest_roots.last().expect("Chain cannot be empty"),
faulty_head: *faulty_roots.last().expect("Chain cannot be empty"),
honest_roots,
faulty_roots,
}
}
pub fn store_clone(&self) -> MemoryStore<TestEthSpec> {
(*self.harness.chain.store).clone()
}
/// Return a brand-new, empty fork choice with a reference to `harness.store`.
pub fn new_fork_choice(&self) -> ThreadSafeReducedTree {
// Take a full clone of the store built by the harness.
//
// Taking a clone here ensures that each fork choice gets it's own store so there is no
// cross-contamination between tests.
let store: MemoryStore<TestEthSpec> = self.store_clone();
ThreadSafeReducedTree::new(
Arc::new(store),
&self.genesis_block,
self.genesis_block_root,
)
}
pub fn all_block_roots(&self) -> Vec<RootAndSlot> {
let mut all_roots = self.honest_roots.clone();
all_roots.append(&mut self.faulty_roots.clone());
all_roots.dedup();
all_roots
}
pub fn weight_function(_validator_index: usize) -> Option<u64> {
Some(1)
}
}
/// Helper: returns all the ancestor roots and slots for a given block_root.
fn get_ancestor_roots<U: Store<TestEthSpec>>(
store: Arc<U>,
block_root: Hash256,
) -> Vec<(Hash256, Slot)> {
let block = store
.get::<BeaconBlock<TestEthSpec>>(&block_root)
.expect("block should exist")
.expect("store should not error");
<BeaconBlock<TestEthSpec> as AncestorIter<_, _, _>>::try_iter_ancestor_roots(&block, store)
.expect("should be able to create ancestor iter")
.collect()
}
/// Helper: returns the slot for some block_root.
fn get_slot_for_block_root(harness: &BeaconChainHarness, block_root: Hash256) -> Slot {
harness
.chain
.store
.get::<BeaconBlock<TestEthSpec>>(&block_root)
.expect("head block should exist")
.expect("DB should not error")
.slot
}
const RANDOM_ITERATIONS: usize = 50;
const RANDOM_ACTIONS_PER_ITERATION: usize = 100;
/// Create a single LMD instance and have one validator vote in reverse (highest to lowest slot)
/// down the chain.
#[test]
fn random_scenario() {
let harness = &FORKED_HARNESS;
let block_roots = harness.all_block_roots();
let validators: Vec<usize> = (0..VALIDATOR_COUNT).collect();
let mut rng = StdRng::seed_from_u64(9375205782030385); // Keyboard mash.
for _ in 0..RANDOM_ITERATIONS {
let lmd = harness.new_fork_choice();
for _ in 0..RANDOM_ACTIONS_PER_ITERATION {
let (root, slot) = block_roots[rng.next_u64() as usize % block_roots.len()];
let validator_index = validators[rng.next_u64() as usize % validators.len()];
lmd.process_attestation(validator_index, root, slot)
.expect("fork choice should accept randomly-placed attestations");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"New tree should have integrity"
);
}
}
}
/// Create a single LMD instance and have one validator vote in reverse (highest to lowest slot)
/// down the chain.
#[test]
fn single_voter_persistent_instance_reverse_order() {
let harness = &FORKED_HARNESS;
let lmd = harness.new_fork_choice();
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"New tree should have integrity"
);
for (root, slot) in &harness.honest_roots {
lmd.process_attestation(0, *root, *slot)
.expect("fork choice should accept attestations to honest roots in reverse");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained whilst processing attestations"
);
}
// The honest head should be selected.
let (head_root, _) = harness.honest_roots.first().unwrap();
let (finalized_root, finalized_slot) = harness.honest_roots.last().unwrap();
assert_eq!(
lmd.find_head(
*finalized_slot,
*finalized_root,
ForkedHarness::weight_function
),
Ok(*head_root),
"Honest head should be selected"
);
}
/// A single validator applies a single vote to each block in the honest fork, using a new tree
/// each time.
#[test]
fn single_voter_many_instance_honest_blocks_voting_forwards() {
let harness = &FORKED_HARNESS;
for (root, slot) in harness.honest_roots.iter().rev() {
let lmd = harness.new_fork_choice();
lmd.process_attestation(0, *root, *slot)
.expect("fork choice should accept attestations to honest roots");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained whilst processing attestations"
);
}
}
/// Same as above, but in reverse order (votes on the highest honest block first).
#[test]
fn single_voter_many_instance_honest_blocks_voting_in_reverse() {
let harness = &FORKED_HARNESS;
// Same as above, but in reverse order (votes on the highest honest block first).
for (root, slot) in &harness.honest_roots {
let lmd = harness.new_fork_choice();
lmd.process_attestation(0, *root, *slot)
.expect("fork choice should accept attestations to honest roots in reverse");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained whilst processing attestations"
);
}
}
/// A single validator applies a single vote to each block in the faulty fork, using a new tree
/// each time.
#[test]
fn single_voter_many_instance_faulty_blocks_voting_forwards() {
let harness = &FORKED_HARNESS;
for (root, slot) in harness.faulty_roots.iter().rev() {
let lmd = harness.new_fork_choice();
lmd.process_attestation(0, *root, *slot)
.expect("fork choice should accept attestations to faulty roots");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained whilst processing attestations"
);
}
}
/// Same as above, but in reverse order (votes on the highest faulty block first).
#[test]
fn single_voter_many_instance_faulty_blocks_voting_in_reverse() {
let harness = &FORKED_HARNESS;
for (root, slot) in &harness.faulty_roots {
let lmd = harness.new_fork_choice();
lmd.process_attestation(0, *root, *slot)
.expect("fork choice should accept attestations to faulty roots in reverse");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained whilst processing attestations"
);
}
}
/// Ensure that votes with slots before the justified slot are not counted.
#[test]
fn discard_votes_before_justified_slot() {
let harness = &FORKED_HARNESS;
let lmd = harness.new_fork_choice();
let (genesis_root, genesis_slot) = *harness.honest_roots.last().unwrap();
// Add attestations from all validators for all honest blocks.
for (root, slot) in harness.honest_roots.iter().rev() {
for i in 0..VALIDATOR_COUNT {
lmd.process_attestation(i, *root, *slot)
.expect("should accept attestations in increasing order");
}
// Head starting from 0 checkpoint (genesis) should be current root
assert_eq!(
lmd.find_head(genesis_slot, genesis_root, ForkedHarness::weight_function),
Ok(*root),
"Honest head should be selected"
);
// Head from one slot after genesis should still be genesis, because the successor
// block of the genesis block has slot `genesis_slot + 1` which isn't greater than
// the slot we're starting from. This is a very artifical test, but one that's easy to
// describe.
assert_eq!(
lmd.find_head(
genesis_slot + 1,
genesis_root,
ForkedHarness::weight_function
),
Ok(genesis_root)
);
}
}
/// Ensures that the finalized root can be set to all values in `roots`.
fn test_update_finalized_root(roots: &[(Hash256, Slot)]) {
let harness = &FORKED_HARNESS;
let lmd = harness.new_fork_choice();
for (root, _slot) in roots.iter().rev() {
let block = harness
.store_clone()
.get::<BeaconBlock<TestEthSpec>>(root)
.expect("block should exist")
.expect("db should not error");
lmd.update_finalized_root(&block, *root)
.expect("finalized root should update for faulty fork");
assert_eq!(
lmd.verify_integrity(),
Ok(()),
"Tree integrity should be maintained after updating the finalized root"
);
}
}
/// Iterates from low-to-high slot through the faulty roots, updating the finalized root.
#[test]
fn update_finalized_root_faulty() {
let harness = &FORKED_HARNESS;
test_update_finalized_root(&harness.faulty_roots)
}
/// Iterates from low-to-high slot through the honest roots, updating the finalized root.
#[test]
fn update_finalized_root_honest() {
let harness = &FORKED_HARNESS;
test_update_finalized_root(&harness.honest_roots)
}