Declare one fanout queue for each websocket client

- Add license
- Make package installable
- Add one single test

Author: Marco Paolini

.gitignore

@@ -22,3 +22,5 @@ build
 *.egg
 *.manifest
 *.spec
+/.tox
+/.cache

LICENSE.txt

@@ -0,0 +1,9 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Marco Paolini
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

MANIFEST.in

@@ -0,0 +1,2 @@
+include README.md
+include requirements.txt

pushpull/__init__.py

@@ -12,28 +12,34 @@ class Exchanger:
     ROLE_WS = 1
     ROLE_APP = 2
 
-    def __init__(self, name, role, **connection_params):
+    def __init__(self, name, role, client_id=0, **connection_params):
         self._conn_params = connection_params
         if role not in [self.ROLE_WS, self.ROLE_APP]:
             raise ValueError('bad role {}'.format(role))
         self.role = role
-        self.q_names = [x.format(name) for x in ('{}.from_ws', '{}.to_ws')]
-        if role == self.ROLE_APP:
-            self.q_names.reverse()
+        self.client_id = client_id
+        self.name = name
 
     async def __aenter__(self):
-        logger.debug('connecting sender and receiver')
+        logger.debug('connecting with role {}'.format(self.role))
         self._conn = await asynqp.connect(**self._conn_params)
         self._chan = await self._conn.open_channel()
-        queues, exchanges = [], []
-        for name in self.q_names:
-            exchange = await self._chan.declare_exchange(name, 'direct')
-            exchanges.append(exchange)
-            queue = await self._chan.declare_queue(name)
-            await queue.bind(exchange, name)
-            queues.append(queue)
-        logger.debug('connected sender and receiver')
-        return Sender(exchanges[0], self.q_names[0]), Receiver(queues[1])
+        app_routing_key = '{}.app'.format(self.name)
+        app_exchange = await self._chan.declare_exchange(app_routing_key, 'fanout')
+        ws_routing_key = '{}.ws'.format(self.name)
+        ws_exchange = await self._chan.declare_exchange(ws_routing_key, 'direct')
+        if self.role == self.ROLE_WS:
+            receive_queue = await self._chan.declare_queue('{}.ws.{}'.format(self.name, self.client_id))
+            await receive_queue.bind(app_exchange, app_routing_key)
+            send_exchange = ws_exchange
+            send_routing_key = ws_routing_key
+        if self.role == self.ROLE_APP:
+            receive_queue = await self._chan.declare_queue('{}.app'.format(self.name))
+            await receive_queue.bind(ws_exchange, ws_routing_key)
+            send_exchange = app_exchange
+            send_routing_key = app_routing_key
+        logger.debug('connected ok')
+        return Sender(send_exchange, send_routing_key), Receiver(receive_queue)
 
     async def __aexit__(self, exc_type, exc_value, traceback):
         logger.debug('closing connection and channel %r %r', exc_type, exc_value)

pushpull/amqp/gateway.py

@@ -18,7 +18,8 @@ def client():
 @click.argument('name')
 def challenge_websocket(url, name):
     logging.basicConfig(level=logging.DEBUG)
-    click.echo(asyncio.get_event_loop().run_until_complete(websocket_client.challenge(url, name, sys.stdin, sys.stdout)))
+    loop = asyncio.get_event_loop()
+    click.echo(loop.run_until_complete(websocket_client.challenge(url, name, sys.stdin, sys.stdout, loop)))
 client.add_command(challenge_websocket)
 
 

pushpull/cli/client.py

@@ -9,21 +9,21 @@
 logger = logging.getLogger(__name__)
 
 
-async def challenge(url, name, fd_in, fd_out):
-    with aiohttp.ClientSession() as session:
+async def challenge(url, name, fd_in, fd_out, loop=None):
+    with aiohttp.ClientSession(loop=loop) as session:
         async with session.ws_connect('{}?name={}'.format(url, name)) as ws:
             logger.debug('opening websocket')
-            sender = send_from_fd_to_ws(fd_in, ws)
+            sender = send_from_fd_to_ws(fd_in, ws, loop=loop)
             receiver = send_from_ws_to_fd(ws, fd_out)
-            _, pending = await asyncio.wait([sender, receiver], return_when=asyncio.FIRST_COMPLETED)
+            done, pending = await asyncio.wait([sender, receiver], return_when=asyncio.FIRST_COMPLETED)
             for task in pending:
                 task.cancel()
             logger.debug('closing websocket')
             # await ws.close()
 
 
-async def send_from_fd_to_ws(fd, ws):
-    async for line in FdLineReader(fd):
+async def send_from_fd_to_ws(fd, ws, loop=None):
+    async for line in FdLineReader(fd, loop=loop):
         logger.debug('sending line from fd to ws %r', line)
         ws.send_str(line)
         await ws._writer.writer.drain()

pushpull/websocket/__init__.py

@@ -3,6 +3,7 @@
 """
 import logging
 import asyncio
+import random
 
 import aiohttp
 import aiohttp.web
@@ -14,17 +15,22 @@
 
 
 async def websocket_rabbitmq_gateway(request):
+    # TODO: AUTHENTICATION
     name = request.GET.get('name')
     if not name:
         return aiohttp.web.Response(body=b'name is required', status=400)
     ws = aiohttp.web.WebSocketResponse()
     logger.debug('websocket connection open')
     try:
         await ws.prepare(request)
-        async with Exchanger(name, Exchanger.ROLE_WS) as (amqp_sender, amqp_receiver):
-            send_coro = asyncio.ensure_future(send_from_amqp_to_websocket(amqp_receiver, ws))
-            receive_coro = asyncio.ensure_future(send_from_websocket_to_amqp(ws, amqp_sender))
+        # TODO: get client_id from request
+        async with Exchanger(name, Exchanger.ROLE_WS, client_id=random.randint(1, 100)) as (amqp_sender, amqp_receiver):
+            send_coro = send_from_amqp_to_websocket(amqp_receiver, ws)
+            receive_coro = send_from_websocket_to_amqp(ws, amqp_sender)
             await asyncio.gather(receive_coro, send_coro)
+    except Exception as exc:
+        logger.exception('exception while handling request')
+        raise
     finally:
         logger.debug('websocket connection closing')
         await ws.close()

pushpull/websocket/client.py

@@ -0,0 +1,3 @@
+[flake8]
+max-line-length = 119
+exclude = migrations,tests,tests.py,.svn,CVS,.bzr,.hg,.git,__pycache__