Add initial benchmark framework (#7827)

* Add initial benchmark framework

* Use timer from timeit

homeassistant/scripts/benchmark/__init__.py

@@ -0,0 +1,74 @@
+"""Script to run benchmarks."""
+import asyncio
+import argparse
+from contextlib import suppress
+import logging
+from timeit import default_timer as timer
+
+from homeassistant import core
+
+BENCHMARKS = {}
+
+
+def run(args):
+    """Handle ensure config commandline script."""
+    # Disable logging
+    logging.getLogger('homeassistant.core').setLevel(logging.CRITICAL)
+
+    parser = argparse.ArgumentParser(
+        description=("Run a Home Assistant benchmark."))
+    parser.add_argument('name', choices=BENCHMARKS)
+    parser.add_argument('--script', choices=['benchmark'])
+
+    args = parser.parse_args()
+
+    bench = BENCHMARKS[args.name]
+
+    print('Using event loop:', asyncio.get_event_loop_policy().__module__)
+
+    with suppress(KeyboardInterrupt):
+        while True:
+            loop = asyncio.new_event_loop()
+            hass = core.HomeAssistant(loop)
+            hass.async_stop_track_tasks()
+            runtime = loop.run_until_complete(bench(hass))
+            print('Benchmark {} done in {}s'.format(bench.__name__, runtime))
+            loop.run_until_complete(hass.async_stop())
+            loop.close()
+
+    return 0
+
+
+def benchmark(func):
+    """Decorator to mark a benchmark."""
+    BENCHMARKS[func.__name__] = func
+    return func
+
+
+@benchmark
+@asyncio.coroutine
+def async_million_events(hass):
+    """Run a million events."""
+    count = 0
+    event_name = 'benchmark_event'
+    event = asyncio.Event(loop=hass.loop)
+
+    @core.callback
+    def listener(_):
+        """Handle event."""
+        nonlocal count
+        count += 1
+
+        if count == 10**6:
+            event.set()
+
+    hass.bus.async_listen(event_name, listener)
+
+    start = timer()
+
+    for _ in range(10**6):
+        hass.bus.async_fire(event_name)
+
+    yield from event.wait()
+
+    return timer() - start