Tulip и Асинхронное Программирование в Python 3

Андрей Саломатин
Асинхронный код — просто и эффективно. Tulip позволяет писать приложения, которые используют возможности ОС для асинхронного ввода/вывода. Фреймворк станет частью Python 3.4. Доклад о том, как устроен Tulip и как им пользоваться.

Transcript

1. Tulip и Асинхронное Программирование в Python 3 Андрей Саломатин andreysalomatin.me @filipovskii
2. C10K PROBLEM
3. Решение 1 ПОТОК НА КАЖДОГО КЛИЕНТА
4. Решение 2 ПОТОК НА НЕСКОЛЬКО КЛИЕНТОВ
5. 1 on_data(cl1, header1) Request Response LOOP
6. 1 2 3 Request Response on_data(cl1, header1) write_response(cl1, 400) on_data(cl2, header2) on_data(cl3, header3) 200MB LOOP
7. write_response(cl1, 400) on_data(cl2, header2) on_data(cl3, header3) 1 2 3 Request Response 200MB LOOP
8. 1 2 3 Request Response on_data(cl2, header2) on_data(cl3, header3) on_data(cl2, body2) 200MB 1MB LOOP
9. 1 2 3 Request Response on_data(cl3, header3) on_data(cl2, body2) write_response(cl3, 400) 200MB 1MB LOOP
10. asyncio event loop import asyncio loop = asyncio.get_event_loop() loop.call_soon(func) loop.run_forever() ∞
11. event loop basic api loop.call_soon(cb, *args) loop.call_later(delay, cb, *args) loop.run_forever() loop.stop()
12. BACK< to futures future = asyncio.Future() future.set_result(result) future.set_exception(exception) future.result() future.exception()
13. BACK< to futures } future.done() future.cancelled() future.cancel()
14. BACK< to futures | future.add_done_callback(cb) future.remove_done_callback(cb)
15. CALLBACKS def read_data_from(name): waiter = asyncio.Future() result = “Data from {}”.format(name) loop.call_later(.1, waiter.set_result, result) return waiter def on_data(future): print(future.result()) loop.stop() def read_and_process(): read_data_from('file').add_done_callback(on_data) loop.call_soon(read_and_process) loop.run_forever()
16. COROUTINES def coro_func(): print("Before yield") (yield) print("After yield") return 'coroutine result' coro = coro_func() next(coro) # Before yield next(coro) # After yield
17. COROUTINES @asyncio.coroutine def coro_func(): print("Before yield") (yield) print("After yield") return 'coroutine result' coro = coro_func() next(coro) # Before yield next(coro) # After yield, StopIteration
18. COROUTINES @asyncio.coroutine def coro_usage(): result = yeild from coro_func() print(result) coro = coro_usage() next(coro) # Before yield next(coro) # After yield # coroutine result # StopIteration
19. # read one source, callbacks def on_data(future): print(future.result()) loop.stop() def read_and_process(): future = read_data_from(’file’) future.add_done_callback(on_data) loop.call_soon(read_and_process) loop.run_forever() CALLBACKS
20. # read one source, coroutines @asyncio.coroutine def read_and_process(): future = read_data_from('file') result = yield from future print(result) loop.run_until_complete(read_and_process()) COROUTINES
21. # read two sources sequentially, callbacks def on_data_2(future2): print("Content2: %s" % future2.result()) loop.stop() def on_data_1(future1): print("Content1: %s\n" % future1.result()) future2 = read_data_from('file2') future2.add_done_callback(on_data_2) def read_and_process(): future1 = read_data_from('file1') future1.add_done_callback(on_data_1) loop.call_soon(read_and_process) loop.run_forever() CALLBACKS
22. # read two sources sequentially, coroutines def read_and_process(): future1 = read_data_from('file1') content1 = yield from future1 print("Content1: %s" % content1) future2 = read_data_from('file2') content2 = yield from future2 print("Content2: %s" % content1) loop.run_until_complete(read_and_process()) COROUTINES
23. # read two sources in parallel, callbacks def on_data_2(future): print("Content2: %s\n" % future.result()) # loop.stop() def on_data_1(future): print("Content1: %s\n" % future.result()) # loop.stop() def read_and_process(): future1 = read_data_from('file1') future2 = read_data_from('file2') future1.add_done_callback(on_data_1) future2.add_done_callback(on_data_2) loop.call_soon(read_and_process) loop.run_forever() CALLBACKS
24. # read two sources in parallel, coroutines def read_and_process(): content = asyncio.gather( read_data_from('file1'), read_data_from('file2')) content1, content2 = yield from content print( "Content1: %s\nContent2: %s\n" % \ (content1, content2)) loop.run_until_complete(read_and_process()) COROUTINES
25. Transports & Protocols
26. transport api BaseTransport.close() ReadTransport.pause_reading() ReadTransport.resume_reading() WriteTransport.write(data) WriteTransport.writelines(list_of_data)
27. protocol api BaseProtocol.connection_made(transport) BaseProtocol.connection_lost(exc) Protocol.data_received(data) Protocol.eof_received() BaseProtocol.pause_writing() BaseProtocol.resume_writing()
28. koa.py Coroutine-Based Middleware-Driven Lightweight-Something https://github.com/filipovskii/koa.py
29. koa.py middleware @asyncio.coroutine def log_headers(ctx, nxt): print(ctx.request.headers) yield from nxt @asyncio.coroutine def say_hello(ctx, nxt): ctx.response.status = 200 ctx.response.write('Hello') yield from nxt
30. koa.py application app = Application() app.use(log_headers) app.use(say_hello) app.listen(8000)
31. Спасибо! Андрей Саломатин andreysalomatin.me @filipovskii