Add benches, examples to fork_choice

eth2/fork_choice/benches/benches.rs

@@ -0,0 +1,75 @@
+use criterion::Criterion;
+use criterion::{criterion_group, criterion_main, Benchmark};
+use fork_choice::{test_utils::TestingForkChoiceBuilder, ForkChoice, OptimizedLMDGhost};
+use std::sync::Arc;
+use store::MemoryStore;
+use types::{ChainSpec, EthSpec, FoundationEthSpec};
+
+pub type TestedForkChoice<T, U> = OptimizedLMDGhost<T, U>;
+pub type TestedEthSpec = FoundationEthSpec;
+
+/// Helper function to setup a builder and spec.
+fn setup(
+    validator_count: usize,
+    chain_length: usize,
+) -> (
+    TestingForkChoiceBuilder<MemoryStore, TestedEthSpec>,
+    ChainSpec,
+) {
+    let store = MemoryStore::open();
+    let builder: TestingForkChoiceBuilder<MemoryStore, TestedEthSpec> =
+        TestingForkChoiceBuilder::new(validator_count, chain_length, Arc::new(store));
+    let spec = TestedEthSpec::spec();
+
+    (builder, spec)
+}
+
+/// Benches adding blocks to fork_choice.
+fn add_block(c: &mut Criterion) {
+    let validator_count = 16;
+    let chain_length = 100;
+
+    let (builder, spec) = setup(validator_count, chain_length);
+
+    c.bench(
+        &format!("{}_blocks", chain_length),
+        Benchmark::new("add_blocks", move |b| {
+            b.iter(|| {
+                let mut fc = builder.build::<TestedForkChoice<MemoryStore, TestedEthSpec>>();
+                for (root, block) in builder.chain.iter().skip(1) {
+                    fc.add_block(block, root, &spec).unwrap();
+                }
+            })
+        })
+        .sample_size(10),
+    );
+}
+
+/// Benches fork choice head finding.
+fn find_head(c: &mut Criterion) {
+    let validator_count = 16;
+    let chain_length = 64 * 2;
+
+    let (builder, spec) = setup(validator_count, chain_length);
+
+    let mut fc = builder.build::<TestedForkChoice<MemoryStore, TestedEthSpec>>();
+    for (root, block) in builder.chain.iter().skip(1) {
+        fc.add_block(block, root, &spec).unwrap();
+    }
+
+    let head_root = builder.chain.last().unwrap().0;
+    for i in 0..validator_count {
+        fc.add_attestation(i as u64, &head_root, &spec).unwrap();
+    }
+
+    c.bench(
+        &format!("{}_blocks", chain_length),
+        Benchmark::new("find_head", move |b| {
+            b.iter(|| fc.find_head(&builder.genesis_root(), &spec).unwrap())
+        })
+        .sample_size(10),
+    );
+}
+
+criterion_group!(benches, add_block, find_head);
+criterion_main!(benches);