fix websockets chat example (#591)

websockets/chat/README.md

@@ -1,13 +1,14 @@
 # Websocket chat example
 
-This is extension of the [actix chat example](https://github.com/actix/examples/tree/HEAD/websockets/chat)
+This is a multi-threaded chat server example.
 
-Added features:
+Fancy shiny features:
 
-- Browser WebSocket client
+- Browser-based WebSocket client served from static html+js
 - Chat server runs in separate thread
 - Tcp listener runs in separate thread
 - Application state is shared with the websocket server and a resource at `/count/`
+- Uses actors for improved readability of code in the server.rs implementation
 
 ## Server
 
@@ -17,18 +18,22 @@ Added features:
 - `/join name` - join room, if room does not exist, create new one
 - `/name name` - set session name
 - `some message` - just string, send message to all peers in same room
-- client has to send heartbeat `Ping` messages, if server does not receive a heartbeat message for 10 seconds connection gets dropped
+- client has to respond to heartbeat `Ping` messages, if server does not receive a heartbeat 'Pong' message for 10 seconds connection gets dropped
 
 2. [http://localhost:8080/count/](http://localhost:8080/count/) is a non-websocket endpoint and will affect and display state.
 
 To start server use command: `cargo run --bin websocket-chat-server`
 
-## Client
-
-Client connects to server. Reads input from stdin and sends to server.
-
-To run client use command: `cargo run --bin websocket-chat-client`
-
 ## WebSocket Browser Client
 
 Open url: [http://localhost:8080/](http://localhost:8080/)
+Use two tabs to set up a proper conversation.
+
+## Python Client using aiohttp
+
+Client connects to server. Reads input from stdin and sends to server.
+Fetch the needed python libraries `pip3 install --requirements requirements.txt`
+Then start client as `./client.py`
+
+
+

websockets/chat/client.py

@@ -1,80 +1,76 @@
 #!/usr/bin/env python3
-"""websocket cmd client for actix/websocket-tcp-chat example."""
+"""websocket cmd client for web_ws.py example."""
+
 import argparse
 import asyncio
-import signal
 import sys
+from contextlib import suppress
 
 import aiohttp
 
-queue = asyncio.Queue()
 
+async def start_client(url: str) -> None:
+    name = input("Please enter your name: ")
 
-async def start_client(url, loop):
-    name = input('Please enter your name: ')
-
-    ws = await aiohttp.ClientSession().ws_connect(url, autoclose=False, autoping=False)
-
-    def stdin_callback():
-        line = sys.stdin.buffer.readline().decode('utf-8')
-        if not line:
-            loop.stop()
-        else:
-            # Queue.put is a coroutine, so you can't call it directly.
-            asyncio.ensure_future(queue.put(ws.send_str(name + ': ' + line)))
-
-    loop.add_reader(sys.stdin, stdin_callback)
-
-    async def dispatch():
+    async def dispatch(ws: aiohttp.ClientWebSocketResponse) -> None:
         while True:
             msg = await ws.receive()
+
             if msg.type == aiohttp.WSMsgType.TEXT:
-                print('Text: ', msg.data.strip())
+                print("Text: ", msg.data.strip())
             elif msg.type == aiohttp.WSMsgType.BINARY:
-                print('Binary: ', msg.data)
+                print("Binary: ", msg.data)
             elif msg.type == aiohttp.WSMsgType.PING:
                 await ws.pong()
             elif msg.type == aiohttp.WSMsgType.PONG:
-                print('Pong received')
+                print("Pong received")
             else:
                 if msg.type == aiohttp.WSMsgType.CLOSE:
                     await ws.close()
                 elif msg.type == aiohttp.WSMsgType.ERROR:
-                    print('Error during receive %s' % ws.exception())
+                    print("Error during receive %s" % ws.exception())
                 elif msg.type == aiohttp.WSMsgType.CLOSED:
                     pass
+
                 break
 
-    await dispatch()
+    async with aiohttp.ClientSession() as session:
+        async with session.ws_connect(url, autoclose=False, autoping=False) as ws:
+            # send request
+            dispatch_task = asyncio.create_task(dispatch(ws))
 
+            # Exit with Ctrl+D
+            while line := await asyncio.to_thread(sys.stdin.readline):
+                await ws.send_str(name + ": " + line)
 
-async def tick():
-    while True:
-        await (await queue.get())
-
-
-async def main(url, loop):
-    await asyncio.wait([start_client(url, loop), tick()])
+            dispatch_task.cancel()
+            with suppress(asyncio.CancelledError):
+                await dispatch_task
 
 
 ARGS = argparse.ArgumentParser(
-    description="websocket console client for wssrv.py example.")
+    description="websocket console client for wssrv.py example."
+)
 ARGS.add_argument(
-    '--host', action="store", dest='host',
-    default='127.0.0.1', help='Host name')
+    "--host", action="store", dest="host", default="127.0.0.1", help="Host name"
+)
 ARGS.add_argument(
-    '--port', action="store", dest='port',
-    default=8080, type=int, help='Port number')
+    "--port", action="store", dest="port", default=8080, type=int, help="Port number"
+)
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     args = ARGS.parse_args()
-    if ':' in args.host:
-        args.host, port = args.host.split(':', 1)
+    if ":" in args.host:
+        args.host, port = args.host.split(":", 1)
         args.port = int(port)
 
-    url = 'http://{}:{}/ws/'.format(args.host, args.port)
+    url = f"http://{args.host}:{args.port}/ws"
 
-    loop = asyncio.get_event_loop()
-    loop.add_signal_handler(signal.SIGINT, loop.stop)
-    asyncio.Task(main(url, loop))
-    loop.run_forever()
+    print("""
+    /list 	list all available rooms
+    /join name 	join room, if room does not exist, create new one
+    /name name 	set session name
+    some message 	just string, send message to all peers in same room
+    ctrl-D to exit
+    """)
+    asyncio.run(start_client(url))

websockets/chat/requirements.txt

@@ -0,0 +1 @@
+aiohttp