Add micro-benchmark for attrs classes (#33)

Microbenchmarks for this PR: python/mypy#11328

Author: chadrik

README.md

@@ -24,6 +24,7 @@ Prerequisites:
 * Python 3.7 or later on Linux, macOS, or Windows
 * `mypyc` in `PATH`
 * A working Python C development environment
+* A python environment with mypy test-requirements.txt installed
 
 Display the names of available benchmarks using `runbench.py --list`:
 

microbenchmarks/attrs.py

@@ -0,0 +1,86 @@
+from typing import List, Dict
+
+import attr
+from benchmarking import benchmark
+
+
+@attr.s(auto_attribs=True)
+class C:
+    n: int
+    l: List[str]
+    b: bool
+
+    def add(self, m: int) -> None:
+        self.n = self.get() + m
+
+    def get(self) -> int:
+        return self.n ^ 1
+
+
+@attr.s(auto_attribs=True)
+class C2:
+    l: List[str]
+    n: int
+
+
+@benchmark
+def create_attrs() -> None:
+    N = 40
+    a = [C(1, [], True)] * N
+    l = ['x']
+    for i in range(10000):
+        for n in range(N):
+            a[n] = C(n, l, False)
+        b = []
+        for n in range(N):
+            b.append(C2(n=n, l=l))
+
+
+@benchmark
+def attrs_attr_access() -> None:
+    N = 40
+    a = []
+    for n in range(N):
+        a.append(C(n, [str(n)], n % 3 == 0))
+    c = 0
+    for i in range(100000):
+        for o in a:
+            c += o.n
+            c += len(o.l)
+            if o.b:
+                c -= 1
+            o.n ^= 1
+    assert c == 80600000, c
+
+
+@benchmark
+def attrs_method() -> None:
+    N = 40
+    a = []
+    for n in range(N):
+        a.append(C(n, [str(n)], n % 3 == 0))
+    c = 0
+    for i in range(10000):
+        for o in a:
+            o.add(i & 3)
+            c += o.n
+    assert c == 3007600000, c
+
+
+@attr.s(auto_attribs=True, hash=True)
+class F:
+    n: int
+    s: str
+
+
+@benchmark
+def attrs_as_dict_key() -> None:
+    d: Dict[F, int] = {}
+    a = [F(i % 4, str(i % 3)) for i in range(100)]
+    for i in range(1000):
+        for f in a:
+            if f in d:
+                d[f] += 1
+            else:
+                d[f] = 1
+    assert len(d) == 12, len(d)