278 lines
10 KiB
Rust
278 lines
10 KiB
Rust
use {
|
|
crate::bank::StakeRewards,
|
|
siphasher::sip::SipHasher13,
|
|
solana_sdk::{hash::Hash, pubkey::Pubkey},
|
|
std::hash::Hasher,
|
|
};
|
|
|
|
#[derive(Debug, Clone)]
|
|
pub(crate) struct EpochRewardsHasher {
|
|
hasher: SipHasher13,
|
|
partitions: usize,
|
|
}
|
|
|
|
impl EpochRewardsHasher {
|
|
/// Use SipHasher13 keyed on the `seed` for calculating epoch reward partition
|
|
pub(crate) fn new(partitions: usize, seed: &Hash) -> Self {
|
|
let mut hasher = SipHasher13::new();
|
|
hasher.write(seed.as_ref());
|
|
Self { hasher, partitions }
|
|
}
|
|
|
|
/// Return partition index (0..partitions) by hashing `address` with the `hasher`
|
|
pub(crate) fn hash_address_to_partition(self, address: &Pubkey) -> usize {
|
|
let Self {
|
|
mut hasher,
|
|
partitions,
|
|
} = self;
|
|
hasher.write(address.as_ref());
|
|
let hash64 = hasher.finish();
|
|
|
|
hash_to_partition(hash64, partitions)
|
|
}
|
|
}
|
|
|
|
/// Compute the partition index by modulo the address hash to number of partitions w.o bias.
|
|
/// (rand_int * DESIRED_RANGE_MAX) / (RAND_MAX + 1)
|
|
fn hash_to_partition(hash: u64, partitions: usize) -> usize {
|
|
((partitions as u128)
|
|
.saturating_mul(u128::from(hash))
|
|
.saturating_div(u128::from(u64::MAX).saturating_add(1))) as usize
|
|
}
|
|
|
|
pub(crate) fn hash_rewards_into_partitions(
|
|
stake_rewards: StakeRewards,
|
|
parent_block_hash: &Hash,
|
|
num_partitions: usize,
|
|
) -> Vec<StakeRewards> {
|
|
let hasher = EpochRewardsHasher::new(num_partitions, parent_block_hash);
|
|
let mut result = vec![vec![]; num_partitions];
|
|
|
|
for reward in stake_rewards {
|
|
// clone here so the hasher's state is re-used on each call to `hash_address_to_partition`.
|
|
// This prevents us from re-hashing the seed each time.
|
|
// The clone is explicit (as opposed to an implicit copy) so it is clear this is intended.
|
|
let partition_index = hasher
|
|
.clone()
|
|
.hash_address_to_partition(&reward.stake_pubkey);
|
|
result[partition_index].push(reward);
|
|
}
|
|
result
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use {
|
|
super::*,
|
|
solana_accounts_db::stake_rewards::StakeReward,
|
|
std::{collections::HashMap, ops::RangeInclusive},
|
|
};
|
|
|
|
#[test]
|
|
fn test_get_equal_partition_range() {
|
|
// show how 2 equal partition ranges are 0..=(max/2), (max/2+1)..=max
|
|
// the inclusive is tricky to think about
|
|
let range = get_equal_partition_range(0, 2);
|
|
assert_eq!(*range.start(), 0);
|
|
assert_eq!(*range.end(), u64::MAX / 2);
|
|
let range = get_equal_partition_range(1, 2);
|
|
assert_eq!(*range.start(), u64::MAX / 2 + 1);
|
|
assert_eq!(*range.end(), u64::MAX);
|
|
}
|
|
|
|
#[test]
|
|
fn test_hash_to_partitions() {
|
|
let partitions = 16;
|
|
assert_eq!(hash_to_partition(0, partitions), 0);
|
|
assert_eq!(hash_to_partition(u64::MAX / 16, partitions), 0);
|
|
assert_eq!(hash_to_partition(u64::MAX / 16 + 1, partitions), 1);
|
|
assert_eq!(hash_to_partition(u64::MAX / 16 * 2, partitions), 1);
|
|
assert_eq!(hash_to_partition(u64::MAX / 16 * 2 + 1, partitions), 1);
|
|
assert_eq!(hash_to_partition(u64::MAX - 1, partitions), partitions - 1);
|
|
assert_eq!(hash_to_partition(u64::MAX, partitions), partitions - 1);
|
|
}
|
|
|
|
fn test_partitions(partition: usize, partitions: usize) {
|
|
let partition = partition.min(partitions - 1);
|
|
let range = get_equal_partition_range(partition, partitions);
|
|
// beginning and end of this partition
|
|
assert_eq!(hash_to_partition(*range.start(), partitions), partition);
|
|
assert_eq!(hash_to_partition(*range.end(), partitions), partition);
|
|
if partition < partitions - 1 {
|
|
// first index in next partition
|
|
assert_eq!(
|
|
hash_to_partition(*range.end() + 1, partitions),
|
|
partition + 1
|
|
);
|
|
} else {
|
|
assert_eq!(*range.end(), u64::MAX);
|
|
}
|
|
if partition > 0 {
|
|
// last index in previous partition
|
|
assert_eq!(
|
|
hash_to_partition(*range.start() - 1, partitions),
|
|
partition - 1
|
|
);
|
|
} else {
|
|
assert_eq!(*range.start(), 0);
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn test_hash_to_partitions_equal_ranges() {
|
|
for partitions in [2, 4, 8, 16, 4096] {
|
|
assert_eq!(hash_to_partition(0, partitions), 0);
|
|
for partition in [0, 1, 2, partitions - 1] {
|
|
test_partitions(partition, partitions);
|
|
}
|
|
|
|
let range = get_equal_partition_range(0, partitions);
|
|
for partition in 1..partitions {
|
|
let this_range = get_equal_partition_range(partition, partitions);
|
|
assert_eq!(
|
|
this_range.end() - this_range.start(),
|
|
range.end() - range.start()
|
|
);
|
|
}
|
|
}
|
|
// verify non-evenly divisible partitions (partitions will be different sizes by at most 1 from any other partition)
|
|
for partitions in [3, 19, 1019, 4095] {
|
|
for partition in [0, 1, 2, partitions - 1] {
|
|
test_partitions(partition, partitions);
|
|
}
|
|
let expected_len_of_partition =
|
|
((u128::from(u64::MAX) + 1) / partitions as u128) as u64;
|
|
for partition in 0..partitions {
|
|
let this_range = get_equal_partition_range(partition, partitions);
|
|
let len = this_range.end() - this_range.start();
|
|
// size is same or 1 less
|
|
assert!(
|
|
len == expected_len_of_partition || len + 1 == expected_len_of_partition,
|
|
"{}, {}, {}, {}",
|
|
expected_len_of_partition,
|
|
len,
|
|
partition,
|
|
partitions
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// return start and end_inclusive of `partition` indexes out of from u64::MAX+1 elements in equal `partitions`
|
|
/// These will be equal as long as (u64::MAX + 1) divides by `partitions` evenly
|
|
fn get_equal_partition_range(partition: usize, partitions: usize) -> RangeInclusive<u64> {
|
|
let max_inclusive = u128::from(u64::MAX);
|
|
let max_plus_1 = max_inclusive + 1;
|
|
let partition = partition as u128;
|
|
let partitions = partitions as u128;
|
|
let mut start = max_plus_1 * partition / partitions;
|
|
if partition > 0 && start * partitions / max_plus_1 == partition - 1 {
|
|
// partitions don't evenly divide and the start of this partition needs to be 1 greater
|
|
start += 1;
|
|
}
|
|
|
|
let mut end_inclusive = start + max_plus_1 / partitions - 1;
|
|
if partition < partitions.saturating_sub(1) {
|
|
let next = end_inclusive + 1;
|
|
if next * partitions / max_plus_1 == partition {
|
|
// this partition is far enough into partitions such that the len of this partition is 1 larger than expected
|
|
end_inclusive += 1;
|
|
}
|
|
} else {
|
|
end_inclusive = max_inclusive;
|
|
}
|
|
RangeInclusive::new(start as u64, end_inclusive as u64)
|
|
}
|
|
|
|
/// Make sure that each time hash_address_to_partition is called, it uses the initial seed state and that clone correctly copies the initial hasher state.
|
|
#[test]
|
|
fn test_hasher_copy() {
|
|
let seed = Hash::new_unique();
|
|
let partitions = 10;
|
|
let hasher = EpochRewardsHasher::new(partitions, &seed);
|
|
|
|
let pk = Pubkey::new_unique();
|
|
|
|
let b1 = hasher.clone().hash_address_to_partition(&pk);
|
|
let b2 = hasher.hash_address_to_partition(&pk);
|
|
assert_eq!(b1, b2);
|
|
|
|
// make sure b1 includes the seed's hash
|
|
let mut hasher = SipHasher13::new();
|
|
hasher.write(seed.as_ref());
|
|
hasher.write(pk.as_ref());
|
|
let partition = hash_to_partition(hasher.finish(), partitions);
|
|
assert_eq!(partition, b1);
|
|
}
|
|
|
|
#[test]
|
|
fn test_hash_rewards_into_partitions() {
|
|
// setup the expected number of stake rewards
|
|
let expected_num = 12345;
|
|
|
|
let stake_rewards = (0..expected_num)
|
|
.map(|_| StakeReward::new_random())
|
|
.collect::<Vec<_>>();
|
|
|
|
let total = stake_rewards
|
|
.iter()
|
|
.map(|stake_reward| stake_reward.stake_reward_info.lamports)
|
|
.sum::<i64>();
|
|
|
|
let stake_rewards_in_bucket =
|
|
hash_rewards_into_partitions(stake_rewards.clone(), &Hash::default(), 5);
|
|
|
|
let stake_rewards_in_bucket_clone =
|
|
stake_rewards_in_bucket.iter().flatten().cloned().collect();
|
|
compare(&stake_rewards, &stake_rewards_in_bucket_clone);
|
|
|
|
let total_after_hash_partition = stake_rewards_in_bucket
|
|
.iter()
|
|
.flatten()
|
|
.map(|stake_reward| stake_reward.stake_reward_info.lamports)
|
|
.sum::<i64>();
|
|
|
|
let total_num_after_hash_partition: usize =
|
|
stake_rewards_in_bucket.iter().map(|x| x.len()).sum();
|
|
|
|
// assert total is same, so nothing is dropped or duplicated
|
|
assert_eq!(total, total_after_hash_partition);
|
|
assert_eq!(expected_num, total_num_after_hash_partition);
|
|
}
|
|
|
|
#[test]
|
|
fn test_hash_rewards_into_partitions_empty() {
|
|
let stake_rewards = vec![];
|
|
let total = 0;
|
|
|
|
let num_partitions = 5;
|
|
let stake_rewards_in_bucket =
|
|
hash_rewards_into_partitions(stake_rewards, &Hash::default(), num_partitions);
|
|
|
|
let total_after_hash_partition = stake_rewards_in_bucket
|
|
.iter()
|
|
.flatten()
|
|
.map(|stake_reward| stake_reward.stake_reward_info.lamports)
|
|
.sum::<i64>();
|
|
|
|
assert_eq!(total, total_after_hash_partition);
|
|
|
|
assert_eq!(stake_rewards_in_bucket.len(), num_partitions);
|
|
for bucket in stake_rewards_in_bucket.iter().take(num_partitions) {
|
|
assert!(bucket.is_empty());
|
|
}
|
|
}
|
|
|
|
fn compare(a: &StakeRewards, b: &StakeRewards) {
|
|
let mut a = a
|
|
.iter()
|
|
.map(|stake_reward| (stake_reward.stake_pubkey, stake_reward.clone()))
|
|
.collect::<HashMap<_, _>>();
|
|
b.iter().for_each(|stake_reward| {
|
|
let reward = a.remove(&stake_reward.stake_pubkey).unwrap();
|
|
assert_eq!(&reward, stake_reward);
|
|
});
|
|
assert!(a.is_empty());
|
|
}
|
|
}
|