import asyncio async def application(scope, receive, send): assert scope['type'] == 'http' body = b'' while True: m = await receive() body += m.get('body', b'') if not m.get('more_body', False): break headers = scope.get('headers', []) def get_header(n, v=None): for h in headers: if h[0] == n: return h[1] return v parts = int(get_header(b'x-parts', 1)) delay = int(get_header(b'x-delay', 0)) loop = asyncio.get_event_loop() async def sleep(n): future = loop.create_future() loop.call_later(n, future.set_result, None) await future await send( { 'type': 'http.response.start', 'status': 200, 'headers': [ (b'content-length', str(len(body)).encode()), ], } ) if not body: await sleep(delay) return step = int(len(body) / parts) for i in range(0, len(body), step): await send( { 'type': 'http.response.body', 'body': body[i : i + step], 'more_body': True, } ) await sleep(delay)