Add perftest to devtools (#236)

* Add perftest to devtools

* Add example output from the perf script

* Rename to avoid pytest collection

* Fix git mv failing to remove the original file..

devtools/perftest.py

@@ -0,0 +1,93 @@
+"""Script for testing update performance on devices."""
+import asyncio
+import time
+
+import asyncclick as click
+import pandas as pd
+
+from kasa import Discover
+
+
+async def _update(dev, lock=None):
+    if lock is not None:
+        await lock.acquire()
+        await asyncio.sleep(2)
+    try:
+        start_time = time.time()
+        # print("%s >> Updating" % id(dev))
+        await dev.update()
+        # print("%s >> done in %s" % (id(dev), time.time() - start_time))
+        return {"id": f"{id(dev)}-{dev.model}", "took": (time.time() - start_time)}
+    finally:
+        if lock is not None:
+            lock.release()
+
+
+async def _update_concurrently(devs):
+    start_time = time.time()
+    update_futures = [asyncio.ensure_future(_update(dev)) for dev in devs]
+    await asyncio.gather(*update_futures)
+    return {"type": "concurrently", "took": (time.time() - start_time)}
+
+
+async def _update_sequentially(devs):
+    start_time = time.time()
+
+    for dev in devs:
+        await _update(dev)
+
+    return {"type": "sequential", "took": (time.time() - start_time)}
+
+
+@click.command()
+@click.argument("addrs", nargs=-1)
+@click.option("--rounds", default=5)
+async def main(addrs, rounds):
+    """Test update performance on given devices."""
+    print(f"Running {rounds} rounds on {addrs}")
+    devs = []
+
+    for addr in addrs:
+        try:
+            dev = await Discover.discover_single(addr)
+            devs.append(dev)
+        except Exception as ex:
+            print(f"unable to add {addr}: {ex}")
+
+    data = []
+    test_gathered = True
+
+    if test_gathered:
+        print("=== Testing using gather on all devices ===")
+        for i in range(rounds):
+            data.append(await _update_concurrently(devs))
+            await asyncio.sleep(2)
+
+        await asyncio.sleep(5)
+
+        for i in range(rounds):
+            data.append(await _update_sequentially(devs))
+            await asyncio.sleep(2)
+
+        df = pd.DataFrame(data)
+        print(df.groupby("type").describe())
+
+    print("=== Testing per-device performance ===")
+
+    futs = []
+    data = []
+    locks = {dev: asyncio.Lock() for dev in devs}
+    for i in range(rounds):
+        for dev in devs:
+            futs.append(asyncio.ensure_future(_update(dev, locks[dev])))
+
+    for fut in asyncio.as_completed(futs):
+        res = await fut
+        data.append(res)
+
+    df = pd.DataFrame(data)
+    print(df.groupby("id").describe())
+
+
+if __name__ == "__main__":
+    main(_anyio_backend="asyncio")