from collections.abc import MutableMapping, Mapping
import time


def update_new(left, right):
    if isinstance(right, Mapping):
        for k, v in right.items():
            left[k] = v
        return
    raise RuntimeError


update_old = MutableMapping.update

d_str_small = {f"{i:010}": i for i in range(10)}
d_str_large = {f"{i:010}": i for i in range(1_000_000)}
d_int_small = {i: i for i in range(10)}
d_int_large = {i: i for i in range(1_000_000)}


def count_loops(fn, timeout=5):
    r"""Run `fn` until timeout is reached, counting the number of calls."""
    start = time.time()
    count = 0
    while time.time() - start < timeout:
        fn()
        count += 1
    return count


cases = [
    ("str_small, str_small", d_str_small, d_str_small),
    ("str_small, str_large", d_str_small, d_str_large),
    ("str_large, str_small", d_str_large, d_str_small),
    ("str_large, str_small", d_str_large, d_str_small),
    ("int_small, int_small", d_int_small, d_int_small),
    ("int_small, int_large", d_int_small, d_int_large),
    ("int_large, int_small", d_int_large, d_int_small),
    ("int_large, int_small", d_int_large, d_int_small),
]

results = []
for case, left, right in cases:
    n_new = count_loops(lambda: update_new(left, right))
    n_old = count_loops(lambda: update_old(left, right))
    improvement = (n_new - n_old) / n_old
    result = {
        "Case": case,
        "new": n_new,
        "old": n_old,
        "Improvement (%)": f"{improvement:.1f}",
    }
    results.append(result)
    print(f"{case=} {n_new=:10d}  {n_old=:10d}  {improvement=: 4.1%}", flush=True)