Add benchmark showing that extract::<i64> is costly due to PyNumber_Index trying hard.

Author: adamreichold

Cargo.toml

@@ -169,6 +169,10 @@ harness = false
 name = "bench_intern"
 harness = false
 
+[[bench]]
+name = "bench_extract"
+harness = false
+
 [workspace]
 members = [
     "pyo3-ffi",

benches/bench_extract.rs

@@ -0,0 +1,112 @@
+use criterion::{black_box, criterion_group, criterion_main, Bencher, Criterion};
+
+use pyo3::{
+    types::{PyDict, PyInt, PyString},
+    IntoPy, PyAny, PyObject, Python,
+};
+
+fn extract_str_extract_success(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let s = PyString::new(py, "Hello, World!") as &PyAny;
+
+        bench.iter(|| {
+            let v = black_box(s).extract::<&str>().unwrap();
+            black_box(v);
+        });
+    });
+}
+
+fn extract_str_extract_fail(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let d = PyDict::new(py) as &PyAny;
+
+        bench.iter(|| match black_box(d).extract::<&str>() {
+            Ok(v) => panic!("should err {}", v),
+            Err(e) => black_box(e),
+        });
+    });
+}
+
+fn extract_str_downcast_success(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let s = PyString::new(py, "Hello, World!") as &PyAny;
+
+        bench.iter(|| {
+            let py_str = black_box(s).downcast::<PyString>().unwrap();
+            let v = py_str.to_str().unwrap();
+            black_box(v);
+        });
+    });
+}
+
+fn extract_str_downcast_fail(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let d = PyDict::new(py) as &PyAny;
+
+        bench.iter(|| match black_box(d).downcast::<PyString>() {
+            Ok(v) => panic!("should err {}", v),
+            Err(e) => black_box(e),
+        });
+    });
+}
+
+fn extract_int_extract_success(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let int_obj: PyObject = 123.into_py(py);
+        let int = int_obj.as_ref(py);
+
+        bench.iter(|| {
+            let v = black_box(int).extract::<i64>().unwrap();
+            black_box(v);
+        });
+    });
+}
+
+fn extract_int_extract_fail(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let d = PyDict::new(py) as &PyAny;
+
+        bench.iter(|| match black_box(d).extract::<i64>() {
+            Ok(v) => panic!("should err {}", v),
+            Err(e) => black_box(e),
+        });
+    });
+}
+
+fn extract_int_downcast_success(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let int_obj: PyObject = 123.into_py(py);
+        let int = int_obj.as_ref(py);
+
+        bench.iter(|| {
+            let py_int = black_box(int).downcast::<PyInt>().unwrap();
+            let v = py_int.extract::<i64>().unwrap();
+            black_box(v);
+        });
+    });
+}
+
+fn extract_int_downcast_fail(bench: &mut Bencher<'_>) {
+    Python::with_gil(|py| {
+        let d = PyDict::new(py) as &PyAny;
+
+        bench.iter(|| match black_box(d).downcast::<PyInt>() {
+            Ok(v) => panic!("should err {}", v),
+            Err(e) => black_box(e),
+        });
+    });
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("extract_str_extract_success", extract_str_extract_success);
+    c.bench_function("extract_str_extract_fail", extract_str_extract_fail);
+    c.bench_function("extract_str_downcast_success", extract_str_downcast_success);
+    c.bench_function("extract_str_downcast_fail", extract_str_downcast_fail);
+    c.bench_function("extract_int_extract_success", extract_int_extract_success);
+    c.bench_function("extract_int_extract_fail", extract_int_extract_fail);
+    c.bench_function("extract_int_downcast_success", extract_int_downcast_success);
+    c.bench_function("extract_int_downcast_fail", extract_int_downcast_fail);
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);