import timeit, random, os
def main():
    chunk = b''
    for i in range(512):
        chunk += bytes([random.randint(0, 255)])
    with open('test.file', 'wb') as f:
        start = timeit.default_timer()
        for i in range(1000):
            print(i, end='\r')
            f.write(chunk)
            f.flush()
            os.fsync(f.fileno())
        end = timeit.default_timer()
    print('1000 fsync:', int((end - start) * 1000), 'ms', 'rate:', 1000 / (end - start), 'fsync/s')
main()