# Author: Ovidiu Predescu # Date: July 2011 # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. import asyncio import logging import signal import unittest import warnings from tornado.escape import utf8 from tornado import gen from tornado.httpclient import AsyncHTTPClient from tornado.httpserver import HTTPServer from tornado.ioloop import IOLoop from tornado.testing import bind_unused_port, AsyncTestCase, gen_test from tornado.web import RequestHandler, Application try: from twisted.internet.defer import ( # type: ignore Deferred, inlineCallbacks, returnValue, ) from twisted.internet.protocol import Protocol # type: ignore from twisted.internet.asyncioreactor import AsyncioSelectorReactor # type: ignore from twisted.web.client import Agent, readBody # type: ignore from twisted.web.resource import Resource # type: ignore from twisted.web.server import Site # type: ignore have_twisted = True except ImportError: have_twisted = False else: # Not used directly but needed for `yield deferred` to work. import tornado.platform.twisted # noqa: F401 skipIfNoTwisted = unittest.skipUnless(have_twisted, "twisted module not present") def save_signal_handlers(): saved = {} signals = [signal.SIGINT, signal.SIGTERM] if hasattr(signal, "SIGCHLD"): signals.append(signal.SIGCHLD) for sig in signals: saved[sig] = signal.getsignal(sig) if "twisted" in repr(saved): # This indicates we're not cleaning up after ourselves properly. raise Exception("twisted signal handlers already installed") return saved def restore_signal_handlers(saved): for sig, handler in saved.items(): signal.signal(sig, handler) # Test various combinations of twisted and tornado http servers, # http clients, and event loop interfaces. @skipIfNoTwisted class CompatibilityTests(unittest.TestCase): def setUp(self): self.saved_signals = save_signal_handlers() self.saved_policy = asyncio.get_event_loop_policy() if hasattr(asyncio, "WindowsSelectorEventLoopPolicy"): # Twisted requires a selector event loop, even if Tornado is # doing its own tricks in AsyncIOLoop to support proactors. # Setting an AddThreadSelectorEventLoop exposes various edge # cases so just use a regular selector. asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) # type: ignore self.io_loop = IOLoop() self.io_loop.make_current() self.reactor = AsyncioSelectorReactor() def tearDown(self): self.reactor.disconnectAll() self.io_loop.clear_current() self.io_loop.close(all_fds=True) asyncio.set_event_loop_policy(self.saved_policy) restore_signal_handlers(self.saved_signals) def start_twisted_server(self): class HelloResource(Resource): isLeaf = True def render_GET(self, request): return b"Hello from twisted!" site = Site(HelloResource()) port = self.reactor.listenTCP(0, site, interface="127.0.0.1") self.twisted_port = port.getHost().port def start_tornado_server(self): class HelloHandler(RequestHandler): def get(self): self.write("Hello from tornado!") app = Application([("/", HelloHandler)], log_function=lambda x: None) server = HTTPServer(app) sock, self.tornado_port = bind_unused_port() server.add_sockets([sock]) def run_reactor(self): # In theory, we can run the event loop through Tornado, # Twisted, or asyncio interfaces. However, since we're trying # to avoid installing anything as the global event loop, only # the twisted interface gets everything wired up correectly # without extra hacks. This method is a part of a # no-longer-used generalization that allowed us to test # different combinations. self.stop_loop = self.reactor.stop self.stop = self.reactor.stop self.reactor.run() def tornado_fetch(self, url, runner): client = AsyncHTTPClient() fut = asyncio.ensure_future(client.fetch(url)) fut.add_done_callback(lambda f: self.stop_loop()) runner() return fut.result() def twisted_fetch(self, url, runner): # http://twistedmatrix.com/documents/current/web/howto/client.html chunks = [] client = Agent(self.reactor) d = client.request(b"GET", utf8(url)) class Accumulator(Protocol): def __init__(self, finished): self.finished = finished def dataReceived(self, data): chunks.append(data) def connectionLost(self, reason): self.finished.callback(None) def callback(response): finished = Deferred() response.deliverBody(Accumulator(finished)) return finished d.addCallback(callback) def shutdown(failure): if hasattr(self, "stop_loop"): self.stop_loop() elif failure is not None: # loop hasn't been initialized yet; try our best to # get an error message out. (the runner() interaction # should probably be refactored). try: failure.raiseException() except: logging.error("exception before starting loop", exc_info=True) d.addBoth(shutdown) runner() self.assertTrue(chunks) return b"".join(chunks) def twisted_coroutine_fetch(self, url, runner): body = [None] @gen.coroutine def f(): # This is simpler than the non-coroutine version, but it cheats # by reading the body in one blob instead of streaming it with # a Protocol. client = Agent(self.reactor) response = yield client.request(b"GET", utf8(url)) with warnings.catch_warnings(): # readBody has a buggy DeprecationWarning in Twisted 15.0: # https://twistedmatrix.com/trac/changeset/43379 warnings.simplefilter("ignore", category=DeprecationWarning) body[0] = yield readBody(response) self.stop_loop() self.io_loop.add_callback(f) runner() return body[0] def testTwistedServerTornadoClientReactor(self): self.start_twisted_server() response = self.tornado_fetch( "http://127.0.0.1:%d" % self.twisted_port, self.run_reactor ) self.assertEqual(response.body, b"Hello from twisted!") def testTornadoServerTwistedClientReactor(self): self.start_tornado_server() response = self.twisted_fetch( "http://127.0.0.1:%d" % self.tornado_port, self.run_reactor ) self.assertEqual(response, b"Hello from tornado!") def testTornadoServerTwistedCoroutineClientReactor(self): self.start_tornado_server() response = self.twisted_coroutine_fetch( "http://127.0.0.1:%d" % self.tornado_port, self.run_reactor ) self.assertEqual(response, b"Hello from tornado!") @skipIfNoTwisted class ConvertDeferredTest(AsyncTestCase): @gen_test def test_success(self): @inlineCallbacks def fn(): if False: # inlineCallbacks doesn't work with regular functions; # must have a yield even if it's unreachable. yield returnValue(42) res = yield fn() self.assertEqual(res, 42) @gen_test def test_failure(self): @inlineCallbacks def fn(): if False: yield 1 / 0 with self.assertRaises(ZeroDivisionError): yield fn() if __name__ == "__main__": unittest.main()