python websocket 聊天服务器

向右看齐 2021-09-20 05:08 263阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

前提：

安装

pip install -U channels
    
    add channels to your INSTALLED_APPS setting

服务端：consumers.py

# -*- coding: utf-8 -*-
    from __future__ import unicode_literals
    
    import datetime
    import json
    
    from channels import Group
    from channels.auth import channel_session_user_from_http, channel_session_user
    
    
    @channel_session_user_from_http
    def ws_connect(message, game, room_id):
        # Add to the chat group
        Group(game).add(message.reply_channel)
        # Accept the connection
        message.reply_channel.send({"accept": True})
    
    
    @channel_session_user
    def ws_message(message, game, room_id):
        user = message.user
        if not user.id:
            data = {'stream': 'unauthorized', 'payload': {}}
            Group(game).send({"text": json.dumps(data)}, immediately=True)
            return
    
        data = {
            'stream': 'test',
            'payload': {
                'id': user.id,
                'username': user.username,
            }
        }
        Group(game).send({"text": json.dumps(data)}, immediately=True)
    
    
    @channel_session_user
    def ws_disconnect(message, game, room_id):
        Group(game).discard(message.reply_channel)

路由文件：routing.py

fromchannels.routing import route
    from myapp.consumers import ws_add, ws_message, ws_disconnect
    channel_routing= [
        route("websocket.connect",ws_add,path=r"^/(?P<game>[a-zA-Z]+)/(?P<room_id>[0-9]+)/$"),
        route("websocket.receive",ws_message,path=r"^/(?P<game>[a-zA-Z]+)/(?P<room_id>[0-9]+)/$"),
       route("websocket.disconnect", ws_disconnect,path=r"^/(?P<game>[a-zA-Z]+)/(?P<room_id>[0-9]+)/$"),
    ]

配置文件：setting.py

CHANNEL_LAYERS = {
        "default": {
            "BACKEND": "asgiref.inmemory.ChannelLayer",
            "ROUTING": "common.routing.channel_routing",
        },
    }

它将channel数据存储在内存中的一个字典里，所以不能跨进程。当部署时还是要换成Redis后端asgi\_redis等。

CHANNEL_LAYERS = {
        "default": {
            "BACKEND": "asgi_redis.RedisChannelLayer",
            "CONFIG": {
                "hosts": [("localhost", 6379)],
            },
            "ROUTING": "myproject.routing.channel_routing",
        },
    }

因为Channles是分布式系统，默认它按workers从队列中获得的顺序处理消息。很可能interface server发出非常近的connect和receive消息，connect还未被处理完，receive就被另一个worker处理。

Channels的解决方法是enforce\_ordering装饰器。所有websocket消息都包含一个order键，这个装饰器用这个键确保message按顺序处理。有两个模式：

Slightordering：connect先处理，其他无序。

Strictordering：所有都按序。

参考：http://blog.csdn.net/linshiyx/article/details/51680418

http://blog.csdn.net/zhu\_free/article/details/48137375

http://www.toutiao.com/i6396086415800664577/

https://github.com/jacobian/channels-example

转载于:https://my.oschina.net/jamescasta/blog/876273

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20210726/bbb945125a6f47d6b4703235aac4dc89.png