use asyncio instead of tornado to handle websocket stuff

woodwind/tasks.py

@@ -210,7 +210,8 @@ def notify_feed_updated(session, feed, entries):
                     for e in entries
                 ],
             })
-            redis.publish('woodwind_notify', message)
+            for topic in 'user:{}'.format(user.id), 'feed:{}'.format(feed.id):
+                redis.publish('woodwind_notify:{}'.format(topic), message)
 
 
 def is_content_equal(e1, e2):

woodwind/websocket_server.py

@@ -1,56 +1,22 @@
-import itertools
-import json
-import redis
-import threading
-import tornado.ioloop
-import tornado.websocket
+import websockets
+import asyncio
+import asyncio_redis
 
 
-SUBSCRIBERS = {}
+@asyncio.coroutine
+def handle_subscription(websocket, path):
+    topic = yield from websocket.recv()
+    redis = yield from asyncio_redis.Connection.create()
+    ps = yield from redis.start_subscribe()
+    yield from ps.subscribe(['woodwind_notify:' + topic])
+    while True:
+        message = yield from ps.next_published()
+        if not websocket.open:
+            break
+        yield from websocket.send(message.value)
+    redis.close()
 
 
-def redis_loop():
-    r = redis.StrictRedis()
-    ps = r.pubsub()
-    ps.subscribe('woodwind_notify')
-    for message in ps.listen():
-        if message['type'] == 'message':
-            msg_data = str(message.get('data'), 'utf-8')
-            msg_blob = json.loads(msg_data)
-            user_topic = 'user:{}'.format(msg_blob.get('user'))
-            feed_topic = 'feed:{}'.format(msg_blob.get('feed'))
-            for subscriber in itertools.chain(
-                    SUBSCRIBERS.get(user_topic, []),
-                    SUBSCRIBERS.get(feed_topic, [])):
-                tornado.ioloop.IOLoop.instance().add_callback(
-                    lambda: subscriber.forward_message(msg_data))
-
-
-class WSHandler(tornado.websocket.WebSocketHandler):
-    def check_origin(self, origin):
-        return True
-
-    def forward_message(self, message):
-        try:
-            self.write_message(message)
-        except tornado.websocket.WebSocketClosedError:
-            self.on_close()
-
-    def on_message(self, topic):
-        self.topic = topic
-        SUBSCRIBERS.setdefault(topic, []).append(self)
-
-    def on_close(self):
-        if hasattr(self, 'topic'):
-            SUBSCRIBERS.get(self.topic, []).remove(self)
-
-
-application = tornado.web.Application([
-    (r'/', WSHandler),
-])
-
-
-if __name__ == '__main__':
-    threading.Thread(target=redis_loop).start()
-    application.listen(8077)
-    tornado.ioloop.IOLoop.instance().start()
+asyncio.get_event_loop().run_until_complete(
+    websockets.serve(handle_subscription, 'localhost', 8077))
+asyncio.get_event_loop().run_forever()