key insertion is linear in size of document #540

#!/usr/bin/env python3

import gc
import time

import tomlkit


def insert_keys(n: int) -> float:
    doc = tomlkit.parse("[t]\n")
    table = doc["t"]

    gc.collect()
    gc.disable()
    try:
        start = time.perf_counter()
        for i in range(n):
            table[f"k{i}"] = i
        elapsed = time.perf_counter() - start
    finally:
        gc.enable()

    return elapsed


def main() -> None:
    print()
    print(f"{'N':>7} {'total (ms)':>12} {'us/key':>10} {'ratio':>7}")

    prev = None
    for n in (500, 1000, 2000, 4000, 8000):
        elapsed = insert_keys(n)
        total_ms = elapsed * 1e3
        us_per_key = elapsed / n * 1e6
        ratio = "" if prev is None else f"{elapsed / prev:6.2f}x"
        print(f"{n:>7} {total_ms:12.2f} {us_per_key:10.2f} {ratio:>7}")
        prev = elapsed


if __name__ == "__main__":
    main()