add benchmark for class / method calls (#4016)

pytests/src/pyclasses.rs

@@ -11,6 +11,12 @@ impl EmptyClass {
     fn new() -> Self {
         EmptyClass {}
     }
+
+    fn method(&self) {}
+
+    fn __len__(&self) -> usize {
+        0
+    }
 }
 
 /// This is for demonstrating how to return a value from __next__

pytests/tests/test_pyclasses.py

@@ -8,14 +8,38 @@ def test_empty_class_init(benchmark):
     benchmark(pyclasses.EmptyClass)
 
 
+def test_method_call(benchmark):
+    obj = pyclasses.EmptyClass()
+    assert benchmark(obj.method) is None
+
+
+def test_proto_call(benchmark):
+    obj = pyclasses.EmptyClass()
+    assert benchmark(len, obj) == 0
+
+
 class EmptyClassPy:
+    def method(self):
         pass
 
+    def __len__(self) -> int:
+        return 0
+
 
 def test_empty_class_init_py(benchmark):
     benchmark(EmptyClassPy)
 
 
+def test_method_call_py(benchmark):
+    obj = EmptyClassPy()
+    assert benchmark(obj.method) == pyclasses.EmptyClass().method()
+
+
+def test_proto_call_py(benchmark):
+    obj = EmptyClassPy()
+    assert benchmark(len, obj) == len(pyclasses.EmptyClass())
+
+
 def test_iter():
     i = pyclasses.PyClassIter()
     assert next(i) == 1