Compute diff of validators list manually

beacon_node/store/Cargo.toml

@@ -7,6 +7,8 @@ edition = { workspace = true }
 [dev-dependencies]
 tempfile = { workspace = true }
 beacon_chain = { workspace = true }
+criterion = { workspace = true }
+rand = { workspace = true }
 
 [dependencies]
 db-key = "0.0.5"
@@ -31,3 +33,7 @@ zstd = { workspace = true }
 bls = { workspace = true }
 smallvec = { workspace = true }
 logging = { workspace = true }
+
+[[bench]]
+name = "hdiff"
+harness = false

beacon_node/store/benches/hdiff.rs

@@ -0,0 +1,116 @@
+use bls::PublicKeyBytes;
+use criterion::{criterion_group, criterion_main, Criterion};
+use rand::Rng;
+use ssz::Decode;
+use store::{
+    hdiff::{HDiff, HDiffBuffer},
+    StoreConfig,
+};
+use types::{BeaconState, Epoch, Eth1Data, EthSpec, MainnetEthSpec as E, Validator};
+
+pub fn all_benches(c: &mut Criterion) {
+    let spec = E::default_spec();
+    let genesis_time = 0;
+    let eth1_data = Eth1Data::default();
+    let mut rng = rand::thread_rng();
+    let validator_mutations = 1000;
+    let validator_additions = 100;
+
+    for n in [1_000_000, 1_500_000, 2_000_000] {
+        let mut source_state = BeaconState::<E>::new(genesis_time, eth1_data.clone(), &spec);
+
+        for _ in 0..n {
+            append_validator(&mut source_state, &mut rng);
+        }
+
+        let mut target_state = source_state.clone();
+        // Change all balances
+        for i in 0..n {
+            let balance = target_state.balances_mut().get_mut(i).unwrap();
+            *balance += rng.gen_range(1..=1_000_000);
+        }
+        // And some validator records
+        for _ in 0..validator_mutations {
+            let index = rng.gen_range(1..n);
+            // TODO: Only change a few things, and not the pubkey
+            *target_state.validators_mut().get_mut(index).unwrap() = rand_validator(&mut rng);
+        }
+        for _ in 0..validator_additions {
+            append_validator(&mut target_state, &mut rng);
+        }
+
+        bench_against_states(
+            c,
+            source_state,
+            target_state,
+            &format!("n={n} v_mut={validator_mutations} v_add={validator_additions}"),
+        );
+    }
+}
+
+fn bench_against_states(
+    c: &mut Criterion,
+    source_state: BeaconState<E>,
+    target_state: BeaconState<E>,
+    id: &str,
+) {
+    let slot_diff = target_state.slot() - source_state.slot();
+    let config = StoreConfig::default();
+    let source = HDiffBuffer::from_state(source_state);
+    let target = HDiffBuffer::from_state(target_state);
+    let diff = HDiff::compute(&source, &target, &config).unwrap();
+    println!(
+        "state slot diff {slot_diff} - diff size {id} {}",
+        diff.size()
+    );
+
+    c.bench_function(&format!("compute hdiff {id}"), |b| {
+        b.iter(|| {
+            HDiff::compute(&source, &target, &config).unwrap();
+        })
+    });
+    c.bench_function(&format!("apply hdiff {id}"), |b| {
+        b.iter(|| {
+            let mut source = source.clone();
+            diff.apply(&mut source, &config).unwrap();
+        })
+    });
+}
+
+fn rand_validator(mut rng: impl Rng) -> Validator {
+    let mut pubkey = [0u8; 48];
+    rng.fill_bytes(&mut pubkey);
+    let withdrawal_credentials: [u8; 32] = rng.gen();
+
+    Validator {
+        pubkey: PublicKeyBytes::from_ssz_bytes(&pubkey).unwrap(),
+        withdrawal_credentials: withdrawal_credentials.into(),
+        slashed: false,
+        effective_balance: 32_000_000_000,
+        activation_eligibility_epoch: Epoch::max_value(),
+        activation_epoch: Epoch::max_value(),
+        exit_epoch: Epoch::max_value(),
+        withdrawable_epoch: Epoch::max_value(),
+    }
+}
+
+fn append_validator(state: &mut BeaconState<E>, mut rng: impl Rng) {
+    state
+        .balances_mut()
+        .push(32_000_000_000 + rng.gen_range(1..=1_000_000_000))
+        .unwrap();
+    if let Ok(inactivity_scores) = state.inactivity_scores_mut() {
+        inactivity_scores.push(0).unwrap();
+    }
+    state
+        .validators_mut()
+        .push(rand_validator(&mut rng))
+        .unwrap();
+}
+
+criterion_group! {
+  name = benches;
+  config = Criterion::default().sample_size(10);
+  targets = all_benches
+}
+criterion_main!(benches);