add bench

Author: howardjohn

Cargo.toml

@@ -63,6 +63,10 @@ harness = false
 name = "family"
 harness = false
 
+[[bench]]
+name = "histogram"
+harness = false
+
 [[bench]]
 name = "text"
 path = "benches/encoding/text.rs"

benches/histogram.rs

@@ -0,0 +1,30 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use prometheus_client::metrics::histogram::{exponential_buckets, Histogram};
+use prometheus_client::metrics::native_histogram::NativeHistogram;
+
+const OBSERVATION: f64 = 64.0;
+
+pub fn histogram(c: &mut Criterion) {
+    let mut group = c.benchmark_group("observe");
+
+    group.bench_function("histogram", |b| {
+        let histogram = Histogram::new(exponential_buckets(1.0, 2.0, 10));
+
+        b.iter(|| {
+            histogram.observe(black_box(OBSERVATION));
+        })
+    });
+
+    group.bench_function("native histogram", |b| {
+        let histogram = NativeHistogram::new(0);
+
+        b.iter(|| {
+            histogram.observe(black_box(OBSERVATION));
+        })
+    });
+
+    group.finish();
+}
+
+criterion_group!(benches, histogram);
+criterion_main!(benches);