Divan benchmarking PoC

Cargo.toml

@@ -34,6 +34,7 @@ features = ["derive"]
 version = "1.0.61"
 
 [dev-dependencies]
+divan = "0.1.5"
 insta = { version = "1.26.0", default-features = false }
 
 [dev-dependencies.quickcheck]
@@ -49,7 +50,11 @@ unstable = []
 tracing = ["dep:tracing", "dep:tracing-subscriber", "dep:tracing-flame"]
 
 [[bench]]
-name = "bnf"
+name = "criterion"
+harness = false
+
+[[bench]]
+name = "divan"
 harness = false
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

benches/README.md

@@ -34,7 +34,7 @@ These benchmarks are not run during continuous integration testing. But if a dev
 
 #### Flamegraph
 
-> CARGO_PROFILE_BENCH_DEBUG=true cargo flamegraph --bench bnf -- --bench
+> CARGO_PROFILE_BENCH_DEBUG=true cargo flamegraph --bench divan -- --bench
 
 `sudo` may be required for `dtrace` on macOS
 

benches/bnf.rs → benches/criterion.rs

@@ -1,32 +1,11 @@
+mod util;
+
 use bnf::Grammar;
 use criterion::{criterion_group, criterion_main, Criterion};
 use rand::seq::SliceRandom;
 
-#[cfg(feature = "tracing")]
-fn init_tracing() -> impl Drop {
-    use tracing_flame::FlameLayer;
-    use tracing_subscriber::{fmt, prelude::*};
-    let filter_layer = tracing_subscriber::EnvFilter::from_default_env();
-    let fmt_layer = fmt::Layer::default();
-    let (flame_layer, _guard) = FlameLayer::with_file("./tracing.folded").unwrap();
-
-    tracing_subscriber::registry()
-        .with(filter_layer)
-        .with(fmt_layer)
-        .with(flame_layer)
-        .init();
-
-    _guard
-}
-
-#[cfg(not(feature = "tracing"))]
-fn init_tracing() {}
-
 fn examples(c: &mut Criterion) {
-    init_tracing();
-
-    #[cfg(feature = "tracing")]
-    let _span = tracing::span!(tracing::Level::DEBUG, "BENCH EXAMPLES").entered();
+    let _tracing = util::init_tracing();
 
     c.bench_function("parse postal", |b| {
         let input = std::include_str!("../tests/fixtures/postal_address.terminated.input.bnf");

benches/divan.rs

@@ -0,0 +1,90 @@
+mod util;
+
+fn main() {
+    let _tracing = util::init_tracing();
+
+    #[cfg(feature = "tracing")]
+    let _span = tracing::span!(tracing::Level::DEBUG, "BENCH EXAMPLES").entered();
+
+    divan::main();
+}
+
+mod examples {
+    #[divan::bench(min_time = 5, max_time = 60)]
+    fn parse_postal(bencher: divan::Bencher) {
+        let input = divan::black_box(include_str!(
+            "../tests/fixtures/postal_address.terminated.input.bnf"
+        ));
+
+        bencher.bench(|| {
+            input.parse::<bnf::Grammar>().unwrap();
+        });
+    }
+
+    #[divan::bench(min_time = 5, max_time = 60)]
+    fn generate_dna(bencher: divan::Bencher) {
+        bencher
+            .with_inputs(|| {
+                let input = "<dna> ::= <base> | <base> <dna>
+            <base> ::= 'A' | 'C' | 'G' | 'T'";
+                let grammar: bnf::Grammar = input.parse().unwrap();
+                grammar
+            })
+            .bench_refs(|grammar| {
+                grammar.generate().unwrap();
+            });
+    }
+
+    #[divan::bench(min_time = 5, max_time = 60)]
+    fn parse_polish_calculator(bencher: divan::Bencher) {
+        let polish_calc_grammar: bnf::Grammar = "<product> ::= <number> | <op> <product> <product>
+            <op> ::= '+' | '-' | '*' | '/'
+            <number> ::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
+        "
+        .parse()
+        .unwrap();
+
+        // use pseudo random for consistent metrics
+        use rand::seq::SliceRandom;
+        let mut rng: rand::rngs::StdRng = rand::SeedableRng::seed_from_u64(0);
+        let random_walk_count = 100usize;
+        let mut random_walks: Vec<_> = (0..random_walk_count)
+            .map(|_| polish_calc_grammar.generate_seeded(&mut rng).unwrap())
+            .collect();
+
+        random_walks.shuffle(&mut rng);
+        let random_walks = divan::black_box(random_walks);
+        let mut index = (0..random_walk_count).cycle();
+
+        bencher.bench_local(|| {
+            let index = index.next().unwrap();
+            let input = &random_walks[index];
+            polish_calc_grammar
+                .parse_input(input)
+                .for_each(divan::black_box_drop);
+        });
+    }
+
+    #[divan::bench(min_time = 5, max_time = 60)]
+    fn parse_infinite_nullable_grammar(bencher: divan::Bencher) {
+        use rand::Rng;
+
+        let infinite_grammar: bnf::Grammar = "
+                <a> ::= '' | <b>
+                <b> ::= <a>"
+            .parse()
+            .unwrap();
+
+        let mut rng: rand::rngs::StdRng = rand::SeedableRng::seed_from_u64(0);
+
+        bencher
+            .with_inputs(|| rng.gen_range(1..100))
+            .count_inputs_as::<divan::counter::ItemsCount>()
+            .bench_local_values(|parse_count| {
+                infinite_grammar
+                    .parse_input("")
+                    .take(parse_count)
+                    .for_each(divan::black_box_drop);
+            });
+    }
+}

benches/util.rs

@@ -0,0 +1,19 @@
+#[cfg(feature = "tracing")]
+pub fn init_tracing() -> impl Drop {
+    use tracing_flame::FlameLayer;
+    use tracing_subscriber::{fmt, prelude::*};
+    let filter_layer = tracing_subscriber::EnvFilter::from_default_env();
+    let fmt_layer = fmt::Layer::default();
+    let (flame_layer, _guard) = FlameLayer::with_file("./tracing.folded").unwrap();
+
+    tracing_subscriber::registry()
+        .with(filter_layer)
+        .with(fmt_layer)
+        .with(flame_layer)
+        .init();
+
+    _guard
+}
+
+#[cfg(not(feature = "tracing"))]
+pub fn init_tracing() {}