bench: Benchmark header parser

age/Cargo.toml

@@ -120,6 +120,10 @@ bench = false
 name = "test_vectors"
 required-features = ["ssh"]
 
+[[bench]]
+name = "parser"
+harness = false
+
 [[bench]]
 name = "throughput"
 harness = false

age/benches/parser.rs

@@ -0,0 +1,48 @@
+use age::{x25519, Decryptor, Encryptor, Recipient};
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
+
+#[cfg(unix)]
+use pprof::criterion::{Output, PProfProfiler};
+
+use std::io::Write;
+
+fn bench(c: &mut Criterion) {
+    let recipients: Vec<_> = (0..10)
+        .map(|_| Box::new(x25519::Identity::generate().to_public()))
+        .collect();
+    let mut group = c.benchmark_group("header");
+
+    for count in 1..10 {
+        group.throughput(Throughput::Elements(count as u64));
+        group.bench_function(BenchmarkId::new("parse", count), |b| {
+            let mut encrypted = vec![];
+            let mut output = Encryptor::with_recipients(
+                recipients
+                    .iter()
+                    .take(count)
+                    .cloned()
+                    .map(|r| r as Box<dyn Recipient>)
+                    .collect(),
+            )
+            .wrap_output(&mut encrypted)
+            .unwrap();
+            output.write_all(&[]).unwrap();
+            output.finish().unwrap();
+
+            b.iter(|| Decryptor::new(&encrypted[..]))
+        });
+    }
+
+    group.finish();
+}
+
+#[cfg(unix)]
+criterion_group!(
+    name = benches;
+    config = Criterion::default()
+        .with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
+    targets = bench
+);
+#[cfg(not(unix))]
+criterion_group!(benches, bench);
+criterion_main!(benches);